Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 112,966	$ 97,195
Trade accounts receivable, net of allowance for doubtful accounts of $154 and $283, respectively	80,677	66,714
Other accounts receivable	10,488	10,326
Prepaid expenses and other	16,443	16,645
Total current assets	220,574	190,880
Vessels, equipment, and other fixed assets at cost, net of accumulated depreciation of $320,945 and $282,395, respectively	1,150,994	1,191,280
Construction in progress	11,111	2,920
Goodwill	31,767	31,987
Intangibles, net of accumulated amortization of $9,370 and $7,208, respectively	25,228	27,390
Deferred costs and other assets	23,774	19,993
Total assets	1,463,448	1,464,450
Current liabilities:
Current portion of long-term debt	33,333	33,333
Accounts payable	16,273	15,130
Income and other taxes payable	4,418	4,066
Accrued personnel costs	22,134	23,417
Accrued interest expense	2,648	5,757
Other accrued liabilities	7,270	7,676
Total current liabilities	86,076	89,379
Long-term debt	268,146	293,095
Long-term income taxes:
Deferred tax liabilities	102,845	102,509
Other income taxes payable	21,285	19,400
Cash flow hedge	4,577	6,807
Other liabilities	6,718	7,303
Stockholders' equity:
Preferred stock, no par value; 2,000 authorized; no shares issued
Class A Common Stock, $0.01 par value; 60,000 shares authorized; 26,553 and 26,269 shares issued and 26,533 and 26,013 outstanding, respectively; Class B Common Stock $0.01 per value; 60,000 shares authorized; no shares issued	262	259
Additional paid-in capital	376,747	370,218
Retained earnings	562,757	536,468
Accumulated other comprehensive income	34,918	39,137
Treasury stock, at cost	(8,985)	(7,228)
Deferred compensation expense	8,102	7,103
Total stockholders' equity	973,801	945,957
Total liabilities and stockholders' equity	$ 1,463,448	$ 1,464,450