Unaudited Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 19,669,000	$ 21,939,000
Trade accounts receivable, net of allowance for doubtful accounts of $1,466 and $1,480, respectively	28,386,000	40,838,000
Other accounts receivable	7,113,000	7,571,000
Prepaid expenses and other current assets	16,009,000	16,649,000
Total current assets	71,177,000	86,997,000
Vessels, equipment, and other fixed assets at cost, net of accumulated depreciation of $473,341 and $457,670, respectively	1,095,529,000	1,195,669,000
Construction in progress	50,850,000	70,817,000
Deferred costs and other assets	6,413,000	7,769,000
Total assets	1,223,969,000	1,361,252,000
Current liabilities:
Accounts payable	15,674,000	13,170,000
Income and other taxes payable	2,481,000	6,485,000
Accrued personnel costs	10,504,000	12,942,000
Accrued interest expense	1,544,000	9,620,000
Other accrued liabilities	7,125,000	5,316,000
Total current liabilities	37,328,000	47,533,000
Long-term debt	486,090,000	490,589,000
Long-term income taxes:
Deferred tax liabilities	63,060,000	99,439,000
Other income taxes payable	21,041,000	21,351,000
Other liabilities	3,984,000	4,032,000
Stockholders' equity:
Preferred stock, $0.01 par value; 2,000 shares authorized; no shares issued	0	0
Class A Common Stock, $0.01 par value; 60,000 shares authorized; 28,017 and 27,994 shares issued and 25,790 and 25,792 outstanding, respectively; Class B Common Stock $0.01 per value; 60,000 shares authorized; no shares issued	276,000	274,000
Additional paid-in capital	418,208,000	417,289,000
Retained earnings	352,999,000	444,181,000
Accumulated other comprehensive income (loss)	(92,976,000)	(96,234,000)
Treasury stock, at cost	(74,914,000)	(75,922,000)
Deferred compensation expense	8,873,000	8,720,000
Total stockholders' equity	612,466,000	698,308,000
Total liabilities and stockholders' equity	$ 1,223,969,000	$ 1,361,252,000