Unaudited Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 72,701	$ 185,175
Trade accounts receivable, net of allowance for doubtful accounts of $2,624 and $3,250, respectively	115,184	85,706
Other accounts receivable	9,672	8,506
Prepaid expenses and other current assets	23,910	25,186
Total current assets	221,467	304,573
Vessels, equipment, and other fixed assets at cost, net of accumulated depreciation of $400,035 and $389,469, respectively	1,091,529	1,136,360
Construction in progress	258,157	169,429
Goodwill	30,665	33,438
Intangibles, net of accumulated amortization of $14,417 and $12,975, respectively	20,182	21,624
Cash held in escrow	32,258	47,028
Deferred costs and other assets	30,709	33,222
Total assets	1,684,967	1,745,674
Current liabilities:
Accounts payable	23,801	29,089
Income and other taxes payable	4,310	6,262
Accrued personnel costs	19,591	23,656
Accrued interest expense	9,830	9,327
Other accrued liabilities	12,630	11,402
Total current liabilities	70,162	79,736
Long-term debt	500,933	500,999
Long-term income taxes:
Deferred tax liabilities	105,059	105,867
Other income taxes payable	22,444	23,665
Other liabilities	8,257	7,525
Stockholders' equity:
Class A Common Stock, $0.01 par value; 60,000 shares authorized; 27,153 and 26,941 shares issued and 26,796 and 26,906 outstanding, respectively; Class B Common Stock $0.01 per value; 60,000 shares authorized; no shares issued	269	266
Additional paid-in capital	396,565	389,881
Retained earnings	578,605	579,062
Accumulated other comprehensive income	15,386	59,875
Treasury stock, at cost	(19,982)	(11,533)
Deferred compensation expense	7,269	10,331
Total stockholders' equity	978,112	1,027,882
Total liabilities and stockholders' equity	$ 1,684,967	$ 1,745,674