Condensed Consolidating Balance Sheet (Unaudited) (Detail) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 71,368	$ 52,183
Restricted cash	5,163
Accounts receivable, net of allowance	217,857	254,188
Prepaid expenses and other current assets	32,401	21,119
Assets held for sale	12,600
Total current assets	339,389	327,490
Property and equipment, net	2,802,146	2,802,449
Goodwill	43,996	40,927
Non-current deferred tax assets	11,531	12,814
Other assets	95,715	88,718
Total assets	3,292,777	3,272,398
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	277,928	277,804
Income taxes payable	200	3,034
Current portion of long-term debt	6,193	10,000
Total current liabilities	284,321	290,838
Long-term debt, net	1,487,781	1,437,187
Deferred revenue	32,918	39,735
Other liabilities	59,839	53,030
Total liabilities	1,864,859	1,820,790
Total stockholders' equity	1,427,918	1,451,608	$ 1,463,344	$ 1,458,963
Total liabilities and stockholders' equity	3,292,777	3,272,398
Reportable Legal Entities | Parent
ASSETS
Cash and cash equivalents	41,992	25,745
Accounts receivable, net of allowance	151,045	211,673
Prepaid expenses and other current assets	2,824	1,835
Assets held for sale	12,600
Total current assets	208,461	239,253
Property and equipment, net	2,470,999	2,467,166
Goodwill	33,057	26,031
Other assets	488,835	421,474
Total assets	3,201,352	3,153,924
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	275,166	251,011
Income taxes payable	21	1,443
Current portion of long-term debt	6,193	10,000
Total current liabilities	281,380	262,454
Long-term debt, net	1,476,808	1,437,982
Non-current deferred tax liabilities	479	379
Other liabilities	14,767	1,501
Total liabilities	1,773,434	1,702,316
Total stockholders' equity	1,427,918	1,451,608
Total liabilities and stockholders' equity	3,201,352	3,153,924
Reportable Legal Entities | Combined Subsidiary Guarantors
ASSETS
Cash and cash equivalents	29,376	26,438
Accounts receivable, net of allowance	418,744	372,755
Prepaid expenses and other current assets	35,308	24,986
Total current assets	483,428	424,179
Property and equipment, net	324,477	335,283
Goodwill	10,939	14,896
Non-current deferred tax assets	12,010	13,193
Other assets	52,397	69,117
Total assets	883,251	856,668
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	360,213	362,701
Income taxes payable	179	1,591
Total current liabilities	360,392	364,292
Long-term debt, net	114,317	114,205
Deferred revenue	32,918	39,735
Other liabilities	45,072	51,529
Total liabilities	552,699	569,761
Total stockholders' equity	330,552	286,907
Total liabilities and stockholders' equity	883,251	856,668
Reportable Legal Entities | Non-Guarantor Subsidiaries
ASSETS
Restricted cash	5,163
Accounts receivable, net of allowance	(1)
Prepaid expenses and other current assets	14
Total current assets	5,176
Property and equipment, net	6,670
Total assets	11,846
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	190
Total current liabilities	190
Long-term debt, net	11,656
Total liabilities	11,846
Total liabilities and stockholders' equity	11,846
Consolidating Adjustments and Other
ASSETS
Accounts receivable, net of allowance	(351,931)	(330,240)
Prepaid expenses and other current assets	(5,745)	(5,702)
Total current assets	(357,676)	(335,942)
Non-current deferred tax assets	(479)	(379)
Other assets	(445,517)	(401,873)
Total assets	(803,672)	(738,194)
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	(357,641)	(335,908)
Total current liabilities	(357,641)	(335,908)
Long-term debt, net	(115,000)	(115,000)
Non-current deferred tax liabilities	(479)	(379)
Total liabilities	(473,120)	(451,287)
Total stockholders' equity	(330,552)	(286,907)
Total liabilities and stockholders' equity	$ (803,672)	$ (738,194)