Condensed Consolidating Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
ASSETS
Cash and cash equivalents	$ 74,022	$ 74,393
Restricted cash	2,254
Accounts receivable, net of allowance	226,275	248,588
Current deferred tax assets	11,414	13,229
Prepaid expenses and other current assets	29,213	29,775
Total current assets	343,178	365,985
Property and equipment, net	2,720,082	2,658,628
Restricted cash	105	2,858
Investment in direct financing lease	2,617	3,223
Goodwill	15,155	16,110
Non-current deferred tax assets	3,479	2,301
Other assets	75,155	78,086
Total assets	3,159,771	3,127,191
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	316,149	317,566
Income taxes payable	659	1,368
Current liabilities of discontinued operations		54
Total current liabilities	316,808	318,988
Long-term debt	1,240,000	1,200,000
Deferred revenue	91,607	87,227
Other liabilities	37,740	39,476
Total liabilities	1,686,155	1,645,691
Total stockholders' equity	1,473,616	1,481,500	1,499,016	1,502,507
Total liabilities and stockholders' equity	3,159,771	3,127,191
Parent
ASSETS
Cash and cash equivalents	20,456	12,337
Restricted cash	662
Accounts receivable, net of allowance	172,348	167,626
Current deferred tax assets	152
Prepaid expenses and other current assets	3,888	17,060
Total current assets	197,506	197,023
Property and equipment, net	2,485,077	2,459,053
Restricted cash	105	1,267
Investment in direct financing lease	2,617	3,223
Other assets	239,176	241,690
Total assets	2,924,481	2,902,256
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	209,626	218,403
Income taxes payable	1	195
Current deferred tax liabilities		13
Total current liabilities	209,627	218,611
Long-term debt	1,240,000	1,200,000
Non-current deferred tax liabilities	413	477
Other liabilities	825	1,668
Total liabilities	1,450,865	1,420,756
Total stockholders' equity	1,473,616	1,481,500
Total liabilities and stockholders' equity	2,924,481	2,902,256
Combined Subsidiary Guarantors
ASSETS
Cash and cash equivalents	53,566	62,056
Restricted cash	1,592
Accounts receivable, net of allowance	149,751	178,911
Current deferred tax assets	11,262	13,241
Prepaid expenses and other current assets	33,514	34,705
Total current assets	249,685	288,913
Property and equipment, net	235,005	199,575
Restricted cash		1,591
Goodwill	15,155	16,110
Non-current deferred tax assets	3,892	2,778
Other assets	45,874	47,046
Total assets	549,611	556,013
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	210,502	205,213
Income taxes payable	658	1,173
Note payable to an affiliate		13,854
Current liabilities of discontinued operations		54
Total current liabilities	211,160	220,294
Long-term debt	115,000	115,000
Deferred revenue	91,607	87,227
Other liabilities	36,915	37,808
Total liabilities	454,682	460,329
Total stockholders' equity	94,929	95,684
Total liabilities and stockholders' equity	549,611	556,013
Consolidating Adjustments and Other
ASSETS
Accounts receivable, net of allowance	(95,824)	(97,949)
Current deferred tax assets		(12)
Prepaid expenses and other current assets	(8,189)	(21,990)
Total current assets	(104,013)	(119,951)
Non-current deferred tax assets	(413)	(477)
Other assets	(209,895)	(210,650)
Total assets	(314,321)	(331,078)
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	(103,979)	(106,050)
Current deferred tax liabilities		(13)
Note payable to an affiliate		(13,854)
Total current liabilities	(103,979)	(119,917)
Long-term debt	(115,000)	(115,000)
Non-current deferred tax liabilities	(413)	(477)
Total liabilities	(219,392)	(235,394)
Total stockholders' equity	(94,929)	(95,684)
Total liabilities and stockholders' equity	$ (314,321)	$ (331,078)