Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Condensed Consolidated Statements of Operations [Abstract]
Revenue	$ 96,911	$ 92,782	$ 178,200	$ 177,433
Costs and expenses:
Direct operating expenses	46,908	42,658	91,225	85,727
Drydock expense	3,683	6,159	10,207	13,123
General and administrative expenses	10,910	11,456	22,333	23,187
Depreciation and amortization	14,982	13,977	29,658	27,952
(Gain) loss on sale of assets		106	10	106
Impairment Charge		97,665		97,665
Total costs and expenses	76,483	172,021	153,433	247,760
Operating income (loss)	20,428	(79,239)	24,767	(70,327)
Other income (expense):
Interest expense	(5,630)	(5,062)	(11,357)	(10,051)
Interest income	119	37	184	142
Foreign currency gain (loss) and other	73	(1,020)	17	761
Total other expense	(5,438)	(6,045)	(11,156)	(9,148)
Income (loss) before income taxes	14,990	(85,284)	13,611	(79,475)
Income tax (provision) benefit	(1,699)	(5,447)	(1,487)	10,287
Net income (loss)	$ 13,291	$ (90,731)	$ 12,124	$ (69,188)
Earnings (loss) per share:
Basic	$ 0.51	$ (3.55)	$ 0.47	$ (2.72)
Diluted	$ 0.51	$ (3.55)	$ 0.46	$ (2.72)
Weighted average shares outstanding:
Basic	25,829	25,546	25,754	25,470
Diluted	25,949	25,546	25,885	25,470