Condensed Consolidating Balance Sheet (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
ASSETS
Cash and cash equivalents	$ 74,393	$ 77,909
Accounts receivable, net of allowance	248,588	244,957
Current deferred tax assets	13,229	9,241
Prepaid expenses and other current assets	29,775	20,612
Current assets of discontinued operations		15
Total current assets	365,985	352,734
Property and equipment, net	2,658,628	2,546,613
Restricted cash	2,858	5,589
Investment in direct financing lease	3,223	5,473
Goodwill	16,110	16,110
Non-current deferred tax assets	2,301	3,078
Other assets	78,086	77,828
Total assets	3,127,191	3,007,425
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	317,566	252,277
Income taxes payable	1,368	1,243
Current liabilities of discontinued operations	54	886
Total current liabilities	318,988	254,406
Long-term debt	1,200,000	1,205,000
Other liabilities	126,703	45,512
Total liabilities	1,645,691	1,504,918
Total stockholders' equity	1,481,500	1,502,507	1,521,620	1,408,022
Total liabilities and stockholders' equity	3,127,191	3,007,425
Parent
ASSETS
Cash and cash equivalents	12,337	31,647
Accounts receivable, net of allowance	167,626	203,018
Current deferred tax assets		2
Prepaid expenses and other current assets	17,060	7,580
Total current assets	197,023	242,247
Property and equipment, net	2,459,053	2,450,028
Restricted cash	1,267	1,016
Investment in direct financing lease	3,223	5,473
Other assets	241,690	245,028
Total assets	2,902,256	2,943,792
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	218,403	234,277
Income taxes payable	195
Current deferred tax liabilities	13
Total current liabilities	218,611	234,277
Long-term debt	1,200,000	1,205,000
Non-current deferred tax liabilities	477	555
Other liabilities	1,668	1,453
Total liabilities	1,420,756	1,441,285
Total stockholders' equity	1,481,500	1,502,507
Total liabilities and stockholders' equity	2,902,256	2,943,792
Combined Subsidiary Guarantors
ASSETS
Cash and cash equivalents	62,056	46,262
Accounts receivable, net of allowance	178,911	178,894
Current deferred tax assets	13,241	9,239
Prepaid expenses and other current assets	34,705	22,856
Current assets of discontinued operations		15
Total current assets	288,913	257,266
Property and equipment, net	199,575	96,585
Restricted cash	1,591	4,573
Goodwill	16,110	16,110
Non-current deferred tax assets	2,778	3,633
Other assets	47,046	45,149
Total assets	556,013	423,316
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	205,213	164,745
Income taxes payable	1,173	1,243
Note payable to an affiliate	13,854
Current liabilities of discontinued operations	54	886
Total current liabilities	220,294	166,874
Long-term debt	115,000	115,000
Other liabilities	125,035	44,059
Total liabilities	460,329	325,933
Total stockholders' equity	95,684	97,383
Total liabilities and stockholders' equity	556,013	423,316
Consolidating Adjustments and Other
ASSETS
Accounts receivable, net of allowance	(97,949)	(136,955)
Current deferred tax assets	(12)
Prepaid expenses and other current assets	(21,990)	(9,824)
Total current assets	(119,951)	(146,779)
Non-current deferred tax assets	(477)	(555)
Other assets	(210,650)	(212,349)
Total assets	(331,078)	(359,683)
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	(106,050)	(146,745)
Current deferred tax liabilities	(13)
Note payable to an affiliate	(13,854)
Total current liabilities	(119,917)	(146,745)
Long-term debt	(115,000)	(115,000)
Non-current deferred tax liabilities	(477)	(555)
Total liabilities	(235,394)	(262,300)
Total stockholders' equity	(95,684)	(97,383)
Total liabilities and stockholders' equity	$ (331,078)	$ (359,683)