Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 81,489	$ 134,565
Trade accounts receivable, net of allowance of $3,041 and $2,780, respectively	219,227	209,100
Accounts receivable-related parties	69	52
Income tax receivable	2,509	2,553
Inventories	39,619	40,230
Prepaid expenses	11,612	8,796
Other current assets	12,264	13,891
Deferred tax assets	31,168	29,113
Total current assets	397,957	438,300
Property and equipment, net	951,854	943,766
Deferred debt costs, net of amortization	18,060	18,733
Goodwill	115,731	105,836
Other intangible assets, net of amortization	85,383	82,762
Other assets	6,264	6,521
Total assets	1,575,249	1,595,918
Current liabilities:
Accounts payable	50,631	61,740
Accrued expenses	76,666	77,716
Current portion of long-term debt	38,755	38,235
Other current liabilities	333	306
Total current liabilities	166,385	177,997
Long-term debt, net of unamortized premium on notes of $1,630 and $1,683, respectively	847,297	844,906
Deferred tax liabilities	179,670	185,101
Other long-term liabilities	16,998	13,667
Commitments and contingencies
Stockholders' equity:
Preferred stock; $.01 par value; 5,000,000 shares authorized; none designated or issued at March 31, 2013 and December 31, 2012
Common stock; $.01 par value; 80,000,000 shares authorized; 43,500,032 shares issued and 42,224,450 shares outstanding at March 31, 2013; 43,500,032 shares issued and 41,721,299 shares outstanding at December 31, 2012	435	435
Additional paid-in capital	364,990	355,687
Retained earnings	25,735	34,513
Treasury stock, at cost, 1,275,582 and 1,778,803 shares at March 31, 2013 and December 31, 2012, respectively	(26,261)	(16,388)
Total stockholders' equity	364,899	374,247
Total liabilities and stockholders' equity	$ 1,575,249	$ 1,595,918