Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 185,493	$ 161,752
Accounts receivable, net	25,477	29,930
Income taxes receivable	16,782	21,331
Prepaid and other current assets	19,474	10,898
Total Current Assets	247,226	223,911
Property, plant and equipment, net	820,009	831,892
Intangibles, net	962,933	965,745
Goodwill	172,129	172,129
Other assets	11,489	10,955
Total Assets	2,213,786	2,204,632
Current Liabilities:
Accounts payable and accrued liabilities	98,379	117,855
Deferred revenue	17,780	15,008
Current portion of long-term debt	15,938	14,375
Total Current Liabilities	132,097	147,238
Long-term debt	1,157,273	1,160,682
Deferred income taxes	212,864	207,154
Other liabilities	11,642	13,111
Total Liabilities	1,513,876	1,528,185
Commitments and contingencies (refer to note 14)
Stockholders' Equity
Preferred stock ($0.01 par value; 4,000,000 shares authorized; none issued or outstanding)
Common stock ($0.01 par value; 40,000,000 shares authorized; 5,887,899 shares issued; and 5,732,441 and 5,731,442 shares outstanding as of March 31, 2018 and December 31, 2017, respectively)	59	59
Additional paid-in capital	30,750	28,412
Retained earnings	759,004	728,386
Accumulated other comprehensive loss	(351)	(352)
Treasury stock, at cost (155,458 and 156,457 shares held as of March 31, 2018 and December 31, 2017, respectively)	(89,552)	(80,058)
Total Stockholders' Equity	699,910	676,447
Total Liabilities and Stockholders' Equity	$ 2,213,786	$ 2,204,632