Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 98,994	$ 111,532
Trade accounts receivable, net of allowance of $3,339 and $3,675, respectively	232,903	204,394
Accounts receivable - related parties	47	50
Income tax receivable	2,659	3,475
Inventories	40,960	34,240
Prepaid expenses	12,951	9,597
Other current assets	8,898	8,289
Deferred tax assets	29,804	31,436
Total current assets	427,216	403,013
Property and equipment, net	923,232	928,037
Deferred debt costs, net of amortization	14,602	16,145
Goodwill	112,283	110,914
Other intangible assets, net of amortization	73,024	77,555
Other assets	8,499	7,675
Total assets	1,558,856	1,543,339
Current liabilities:
Accounts payable	54,737	45,508
Accrued expenses	84,141	77,058
Current portion of long-term debt	40,577	41,394
Other current liabilities	924	688
Total current liabilities	180,379	164,648
Long-term debt, net of unamortized premium on notes of $1,341 and $1,459, respectively	838,803	846,691
Deferred tax liabilities	163,375	164,306
Other long-term liabilities	25,861	22,407
Commitments and contingencies
Stockholders' equity:
Preferred stock; $0.01 par value; 5,000,000 shares authorized; none designated or issued at June 30, 2014 and December 31, 2013
Common stock; $0.01 par value; 80,000,000 shares authorized; 43,500,032 shares issued and 43,201,279 shares outstanding at June 30, 2014; 43,500,032 shares issued and 42,26,088 shares outstanding at December 31, 2013	435	435
Additional paid-in capital	362,378	363,674
Retained deficit	(6,190)	(6,726)
Treasury stock, at cost, 298,753 and 1,273,944 shares at June 30, 2014 and December 31, 2013, respectively	(6,185)	(12,096)
Total stockholders' equity	350,438	345,287
Total liabilities and stockholders' equity	$ 1,558,856	$ 1,543,339