Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 61,364	$ 86,939
Accounts and notes receivable, net of allowance of $807 and $571 as of June 30, 2014 and December 31, 2013, respectively	62,866	58,274
Inventory, net	6,919	5,302
Restricted cash	27,545	14,896
Current portion of deferred tax asset, net	20,397	21,202
Prepaid expenses, deferred costs, and other current assets	30,229	20,159
Total current assets	209,320	206,772
Property and equipment, net	284,167	270,966
Intangible assets, net	145,254	155,276
Goodwill	412,964	404,491
Deferred tax asset, net	12,119	9,680
Prepaid expenses, deferred costs, and other noncurrent assets	7,716	9,018
Total assets	1,071,540	1,056,203
Current liabilities:
Current portion of long-term debt	615	1,289
Current portion of other long-term liabilities	36,555	35,597
Accounts payable	21,199	38,981
Accrued liabilities	150,124	137,776
Current portion of deferred tax liability, net		1,152
Total current liabilities	208,493	214,795
Long-term liabilities:
Long-term debt	473,613	489,225
Asset retirement obligation	64,881	60,665
Deferred tax liability, net	5,555	5,668
Other long-term liabilities	42,392	38,736
Total liabilities	794,934	809,089
Commitments and contingencies
Stockholders' equity:
Common stock, $0.0001 par value; 125,000,000 shares authorized; 51,477,361 and 51,207,849 shares issued as of June 30, 2014 and December 31, 2013, respectively; 44,472,905 and 44,375,952 shares outstanding as of June 30, 2014 and December 31, 2013, respectively	5	5
Additional paid-in capital	339,842	330,862
Accumulated other comprehensive loss, net	(69,165)	(72,954)
Retained earnings	105,230	81,677
Treasury stock: 7,004,456 and 6,831,897 shares at cost as of June 30, 2014 and December 31, 2013, respectively	(96,824)	(90,679)
Total parent stockholders' equity	279,088	248,911
Noncontrolling interests	(2,482)	(1,797)
Total stockholders' equity	276,606	247,114
Total liabilities and stockholders' equity	$ 1,071,540	$ 1,056,203