Quarterly report pursuant to Section 13 or 15(d)

Segment Information (Operating Results, Capital Expenditures And Assets By Reportable Segments) (Details)

v3.7.0.1
Segment Information (Operating Results, Capital Expenditures And Assets By Reportable Segments) (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Mar. 31, 2017
Dec. 31, 2016
Segment Reporting Information [Line Items]            
Operating Revenues $ 42,323 $ 57,271 $ 76,627 $ 117,150    
Operating Expenses 40,792 39,793 70,580 84,261    
Direct Vessel Profit (Loss) 1,531 17,478 6,047 32,889    
Administrative and general 21,705 11,929 33,531 24,327    
Depreciation and amortization 14,633 15,254 27,136 30,092    
Total costs and expenses 40,028 31,635 67,948 63,253    
Gains (Losses) on Asset Dispositions and Impairments, Net (6,318) (20,357) (1,499) (20,737)    
Operating Income (Loss) (44,815) (34,514) (63,400) (51,101)    
Historical Cost 1,155,155 1,098,914 1,155,155 1,098,914   $ 958,759
Accumulated depreciation (543,822) (556,909) (543,822) (556,909)   (540,619)
Property, Plant and Equipment, Net In Service 611,333 542,005 611,333 542,005    
Investments, at Equity, and Advances to 50% or Less Owned Companies 100,719   100,719     $ 138,311
Income (Loss) from Equity Method Investments 1,571 (3,315) 2,009 (1,154)    
Mexmar [Member]            
Segment Reporting Information [Line Items]            
Investments, at Equity, and Advances to 50% or Less Owned Companies         $ 58,700  
Income (Loss) from Equity Method Investments 1,222 846 2,589 3,431    
Other Offshore Marine Services Joint Ventures [Member]            
Segment Reporting Information [Line Items]            
Investments, at Equity, and Advances to 50% or Less Owned Companies         $ 42,000  
Income (Loss) from Equity Method Investments 349 (4,161) (580) (4,585)    
Personnel [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 20,577 25,841 37,368 53,399    
Repairs and maintenance [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 10,425 5,427 14,020 11,721    
Drydocking [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 2,251 1,963 5,318 5,666    
Insurance and loss reserves [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 2,126 1,103 3,685 2,981    
Fuel, lubes and supplies [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 3,190 3,353 5,532 6,450    
Other [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 2,223 2,106 4,657 4,044    
Leased-in equipment [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 3,690 4,452 7,281 8,834    
Time Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 38,803 49,234 69,533 100,807    
Bareboat Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 1,156 3,045 2,299 5,697    
Other Marine Services Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 2,364 4,992 4,795 10,646    
United States (primarily Gulf of Mexico) [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 6,087 9,780 9,908 21,733    
Operating Expenses 7,231 8,128 12,858 18,364    
Direct Vessel Profit (Loss) (1,144) 1,652 (2,950) 3,369    
Depreciation and amortization 5,749 7,157 11,349 14,034    
Historical Cost 417,675 446,819 417,675 446,819    
Accumulated depreciation 233,758 211,585 233,758 211,585    
Property, Plant and Equipment, Net In Service 183,917 235,234 183,917 235,234    
United States (primarily Gulf of Mexico) [Member] | Personnel [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 4,183 6,368 7,313 14,130    
United States (primarily Gulf of Mexico) [Member] | Repairs and maintenance [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 937 643 1,674 1,402    
United States (primarily Gulf of Mexico) [Member] | Drydocking [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 310 175 883 217    
United States (primarily Gulf of Mexico) [Member] | Insurance and loss reserves [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 1,205 680 2,010 1,679    
United States (primarily Gulf of Mexico) [Member] | Fuel, lubes and supplies [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 545 234 855 747    
United States (primarily Gulf of Mexico) [Member] | Other [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 51 28 123 189    
United States (primarily Gulf of Mexico) [Member] | Leased-in equipment [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 2,205 1,858 4,416 3,720    
United States (primarily Gulf of Mexico) [Member] | Time Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 4,889 8,726 7,884 19,768    
United States (primarily Gulf of Mexico) [Member] | Bareboat Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 0 0 0 0    
United States (primarily Gulf of Mexico) [Member] | Other Marine Services Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 1,198 1,054 2,024 1,965    
Africa Primarily West Africa [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 8,001 9,033 14,040 20,077    
Operating Expenses 9,277 5,789 14,873 11,116    
Direct Vessel Profit (Loss) (1,276) 3,244 (833) 8,961    
Depreciation and amortization 2,059 1,615 3,649 3,193    
Historical Cost 183,661 162,040 183,661 162,040    
Accumulated depreciation 59,300 75,267 59,300 75,267    
Property, Plant and Equipment, Net In Service 124,361 86,773 124,361 86,773    
Africa Primarily West Africa [Member] | Personnel [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 3,428 3,324 6,036 6,409    
Africa Primarily West Africa [Member] | Repairs and maintenance [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 3,234 522 3,778 1,493    
Africa Primarily West Africa [Member] | Drydocking [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 683 426 1,740 584    
Africa Primarily West Africa [Member] | Insurance and loss reserves [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 357 36 539 248    
Africa Primarily West Africa [Member] | Fuel, lubes and supplies [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 704 598 1,263 974    
Africa Primarily West Africa [Member] | Other [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 871 883 1,517 1,408    
Africa Primarily West Africa [Member] | Leased-in equipment [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 969 975 1,939 1,952    
Africa Primarily West Africa [Member] | Time Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 7,786 8,902 13,633 20,041    
Africa Primarily West Africa [Member] | Bareboat Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 0 0 0 0    
Africa Primarily West Africa [Member] | Other Marine Services Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 215 131 407 36    
Middle East and Asia [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 7,524 13,195 14,224 25,436    
Operating Expenses 10,774 8,909 16,966 18,594    
Direct Vessel Profit (Loss) (3,250) 4,286 (2,742) 6,842    
Depreciation and amortization 3,979 3,059 6,506 5,977    
Historical Cost 302,892 224,060 302,892 224,060    
Accumulated depreciation 83,880 95,133 83,880 95,133    
Property, Plant and Equipment, Net In Service 219,012 128,927 219,012 128,927    
Middle East and Asia [Member] | Personnel [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 4,147 5,058 7,270 9,236    
Middle East and Asia [Member] | Repairs and maintenance [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 3,947 1,659 4,523 3,493    
Middle East and Asia [Member] | Drydocking [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 358 (284) 516 1,393    
Middle East and Asia [Member] | Insurance and loss reserves [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 353 151 699 414    
Middle East and Asia [Member] | Fuel, lubes and supplies [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 908 1,498 1,432 2,452    
Middle East and Asia [Member] | Other [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 1,061 827 2,526 1,606    
Middle East and Asia [Member] | Leased-in equipment [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 516 1,123 862 2,299    
Middle East and Asia [Member] | Time Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 7,415 10,554 13,238 18,707    
Middle East and Asia [Member] | Bareboat Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 0 0 0 0    
Middle East and Asia [Member] | Other Marine Services Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 109 2,641 986 6,729    
Brazil, Mexico, Central and South America [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 1,318 3,543 2,536 6,777    
Operating Expenses 298 601 323 2,502    
Direct Vessel Profit (Loss) 1,020 2,942 2,213 4,275    
Depreciation and amortization 784 1,200 1,449 2,399    
Historical Cost 78,976 87,632 78,976 87,632    
Accumulated depreciation 41,565 50,701 41,565 50,701    
Property, Plant and Equipment, Net In Service 37,411 36,931 37,411 36,931    
Brazil, Mexico, Central and South America [Member] | Personnel [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 148 367 161 1,895    
Brazil, Mexico, Central and South America [Member] | Repairs and maintenance [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 116 59 120 207    
Brazil, Mexico, Central and South America [Member] | Drydocking [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 0 0 0 0    
Brazil, Mexico, Central and South America [Member] | Insurance and loss reserves [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 4 (12) 11 37    
Brazil, Mexico, Central and South America [Member] | Fuel, lubes and supplies [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 27 112 27 193    
Brazil, Mexico, Central and South America [Member] | Other [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 3 75 4 170    
Brazil, Mexico, Central and South America [Member] | Leased-in equipment [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 0 367 0 734    
Brazil, Mexico, Central and South America [Member] | Time Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 0 0 0 196    
Brazil, Mexico, Central and South America [Member] | Bareboat Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 1,156 3,045 2,299 5,697    
Brazil, Mexico, Central and South America [Member] | Other Marine Services Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 162 498 237 884    
Europe Primarily North Sea [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 19,393 21,720 35,919 43,127    
Operating Expenses 13,212 16,366 25,560 33,685    
Direct Vessel Profit (Loss) 6,181 5,354 10,359 9,442    
Depreciation and amortization 2,062 2,223 4,183 4,489    
Historical Cost 171,951 178,363 171,951 178,363    
Accumulated depreciation 125,319 124,223 125,319 124,223    
Property, Plant and Equipment, Net In Service 46,632 54,140 46,632 54,140    
Europe Primarily North Sea [Member] | Personnel [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 8,671 10,724 16,588 21,729    
Europe Primarily North Sea [Member] | Repairs and maintenance [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 2,191 2,544 3,925 5,126    
Europe Primarily North Sea [Member] | Drydocking [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 900 1,646 2,179 3,472    
Europe Primarily North Sea [Member] | Insurance and loss reserves [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 207 248 426 603    
Europe Primarily North Sea [Member] | Fuel, lubes and supplies [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 1,006 911 1,955 2,084    
Europe Primarily North Sea [Member] | Other [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 237 293 487 671    
Europe Primarily North Sea [Member] | Leased-in equipment [Member]            
Segment Reporting Information [Line Items]            
Operating Expenses 0 129 64 129    
Europe Primarily North Sea [Member] | Time Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 18,713 21,052 34,778 42,095    
Europe Primarily North Sea [Member] | Bareboat Charter Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues 0 0 0 0    
Europe Primarily North Sea [Member] | Other Marine Services Revenues [Member]            
Segment Reporting Information [Line Items]            
Operating Revenues $ 680 $ 668 $ 1,141 $ 1,032