Consolidated Statements of Operations - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Marine Services Revenue	$ 274,806,000	$ 495,769,000	$ 454,604,000
Costs and expenses:
Direct operating expenses	169,837,000	236,244,000	217,422,000
Drydock expenses	15,387,000	24,840,000	24,094,000
General and administrative expenses	47,280,000	62,728,000	54,527,000
Depreciation and amortization	72,591,000	75,336,000	$ 63,955,000
Impairment charges	152,103,000	8,995,000
(Gain) loss on sale of assets and other	1,160,000	(14,039,000)	$ (5,870,000)
Total costs and expenses	458,358,000	394,104,000	354,128,000
Operating income (loss)	(183,552,000)	101,665,000	100,476,000
Other income (expense):
Interest expense	(36,946,000)	(29,332,000)	(23,821,000)
Interest income	260,000	$ 307,000	$ 202,000
Gain on extinguishment of debt	458,000
Foreign currency loss and other	(1,088,000)	$ (995,000)	$ (1,289,000)
Total other expense	(37,316,000)	(30,020,000)	(24,908,000)
Income (loss) before income taxes	(220,868,000)	71,645,000	75,568,000
Income tax benefit (provision)	5,633,000	(9,270,000)	(4,962,000)
Net income (loss)	$ (215,235,000)	$ 62,375,000	$ 70,606,000
Earnings (loss) per share:
Basic (in dollars per share)	$ (8.70)	$ 2.39	$ 2.70
Diluted (in dollars per share)	$ (8.70)	$ 2.39	$ 2.70
Weighted average shares outstanding:
Basic (in shares)	24,729	26,097	26,175
Diluted (in shares)	24,729	26,097	26,185
Dividend per share (in dollars per share)		$ 1	$ 1