Unaudited Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 25,705	$ 60,566
Trade accounts receivable, net of allowance for doubtful accounts of $223 and $448, respectively	102,854	100,173
Other accounts receivable	12,008	11,194
Prepaid expenses and other current assets	21,269	18,132
Total current assets	161,836	190,065
Vessels, equipment, and other fixed assets at cost, net of accumulated depreciation of $439,781 and $420,355, respectively	1,440,958	1,316,838
Construction in progress	139,334	177,773
Goodwill	31,114	30,676
Intangibles, net of accumulated amortization of $16,578 and $15,858, respectively	18,021	18,741
Cash held in escrow	8,745	8,742
Deferred costs and other assets	29,746	30,457
Total assets	1,829,754	1,773,292
Current liabilities:
Accounts payable	24,586	27,229
Income and other taxes payable	3,398	3,340
Accrued personnel costs	18,960	19,624
Accrued interest expense	1,627	9,892
Other accrued liabilities	11,627	13,432
Total current liabilities	60,198	73,517
Long-term debt	551,760	500,864
Long-term income taxes:
Deferred tax liabilities	104,497	104,647
Other income taxes payable	24,198	23,673
Other liabilities	6,814	7,250
Stockholders' equity:
Class A Common Stock, $0.01 par value; 60,000 shares authorized; 27,315 and 27,165 shares issued and 26,639 and 26,616 outstanding, respectively; Class B Common Stock $0.01 per value; 60,000 shares authorized; no shares issued	270	269
Additional paid-in capital	404,352	402,286
Retained earnings	633,124	623,221
Accumulated other comprehensive income	58,140	49,965
Treasury stock, at cost	(20,570)	(18,690)
Deferred compensation expense	6,971	6,290
Total stockholders' equity	1,082,287	1,063,341
Total liabilities and stockholders' equity	$ 1,829,754	$ 1,773,292