Condensed Consolidating Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011
ASSETS
Cash and cash equivalents	$ 37,875	$ 62,897
Accounts receivable, net of allowance	233,470	252,764
Deferred tax assets	5,416	8,022
Prepaid expenses and other current assets	28,969	27,059
Total current assets	305,730	350,742
Property and equipment, net	2,538,825	2,568,791
Restricted cash	5,673	5,022
Investment in direct financing lease	6,500	7,467
Goodwill	11,158	11,988
Other assets	40,239	30,732
Non-current deferred tax assets	9,035
Total assets	2,917,160	2,974,742
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	228,022	166,000
Income taxes payable	652	102
Current liabilities of discontinued operations	79	356
Total current liabilities	228,753	166,458
Long-term debt	1,150,000	1,111,545
Deferred tax liabilities		139,526
Other liabilities	37,218	35,593
Total liabilities	1,415,971	1,453,122
Total stockholders' equity	1,501,189	1,521,620	1,464,570	1,480,022
Total liabilities and stockholders' equity	2,917,160	2,974,742
Parent
ASSETS
Cash and cash equivalents	8,971
Accounts receivable, net of allowance	318,510	136,128
Deferred tax assets	4	137
Prepaid expenses and other current assets	8,201	1,766
Total current assets	335,686	138,031
Property and equipment, net	2,445,166	2,462,917
Restricted cash	649
Investment in direct financing lease	6,500	7,467
Other assets	212,880	191,502
Total assets	3,000,881	2,799,917
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	348,266	28,061
Total current liabilities	348,266	28,061
Long-term debt	1,150,000	1,111,545
Deferred tax liabilities	526	138,691
Other liabilities	900
Total liabilities	1,499,692	1,278,297
Total stockholders' equity	1,501,189	1,521,620
Total liabilities and stockholders' equity	3,000,881	2,799,917
Combined Subsidiary Guarantors
ASSETS
Cash and cash equivalents	28,904	62,897
Accounts receivable, net of allowance	316,651	255,192
Deferred tax assets	5,412	7,885
Prepaid expenses and other current assets	30,366	35,175
Total current assets	381,333	361,149
Property and equipment, net	93,659	105,874
Restricted cash	5,024	5,022
Goodwill	11,158	11,988
Other assets	18,210	114,953
Non-current deferred tax assets	9,561
Total assets	518,945	598,986
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	291,046	286,342
Income taxes payable	652	102
Current liabilities of discontinued operations	79	356
Total current liabilities	291,777	286,800
Long-term debt	100,000	100,000
Deferred tax liabilities		835
Other liabilities	36,318	35,593
Total liabilities	428,095	423,228
Total stockholders' equity	90,850	175,758
Total liabilities and stockholders' equity	518,945	598,986
Consolidating Adjustments and Other
ASSETS
Accounts receivable, net of allowance	(401,691)	(138,556)
Prepaid expenses and other current assets	(9,598)	(9,882)
Total current assets	(411,289)	(148,438)
Other assets	(190,851)	(275,723)
Non-current deferred tax assets	(526)
Total assets	(602,666)	(424,161)
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	(411,290)	(148,403)
Total current liabilities	(411,290)	(148,403)
Long-term debt	(100,000)	(100,000)
Deferred tax liabilities	(526)
Total liabilities	(511,816)	(248,403)
Total stockholders' equity	(90,850)	(175,758)
Total liabilities and stockholders' equity	$ (602,666)	$ (424,161)