Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 52,183	$ 37,711	$ 65,291	$ 74,393
Accounts receivable, net of allowance	254,188	229,885
Prepaid expenses and other current assets	21,119	31,228
Total current assets	327,490	298,824
Property and equipment, net	2,802,449	2,837,657
Goodwill	40,927	38,386
Non-current deferred tax assets	12,814	13,735
Other assets	88,718	83,002
Total assets	3,272,398	3,271,604
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	277,804	260,107
Income taxes payable	3,034	2,086
Current portion of long-term debt	10,000	10,000
Total current liabilities	290,838	272,193
Long-term debt, net	1,437,187	1,435,169
Deferred revenue	39,735	53,437
Other liabilities	53,030	51,842
Total liabilities	1,820,790	1,812,641
Total stockholders' equity	1,451,608	1,458,963	$ 1,462,748	$ 1,481,500
Total liabilities and stockholders' equity	3,272,398	3,271,604
Reportable Legal Entities | Parent
ASSETS
Cash and cash equivalents	25,745	11,378
Accounts receivable, net of allowance	211,673	237,495
Prepaid expenses and other current assets	1,835	7,582
Total current assets	239,253	256,455
Property and equipment, net	2,467,166	2,493,025
Goodwill	26,031	23,231
Other assets	421,474	339,391
Total assets	3,153,924	3,112,102
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	251,011	203,074
Income taxes payable	1,443	1,850
Current portion of long-term debt	10,000	10,000
Total current liabilities	262,454	214,924
Long-term debt, net	1,437,982	1,436,186
Non-current deferred tax liabilities	379	321
Other liabilities	1,501	1,708
Total liabilities	1,702,316	1,653,139
Total stockholders' equity	1,451,608	1,458,963
Total liabilities and stockholders' equity	3,153,924	3,112,102
Reportable Legal Entities | Combined Subsidiary Guarantors
ASSETS
Cash and cash equivalents	26,438	26,333
Accounts receivable, net of allowance	372,755	270,952
Prepaid expenses and other current assets	24,986	30,123
Total current assets	424,179	327,408
Property and equipment, net	335,283	344,632
Goodwill	14,896	15,155
Non-current deferred tax assets	13,193	14,056
Other assets	69,117	57,873
Total assets	856,668	759,124
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	362,701	342,072
Income taxes payable	1,591	236
Total current liabilities	364,292	342,308
Long-term debt, net	114,205	113,983
Deferred revenue	39,735	53,437
Other liabilities	51,529	50,134
Total liabilities	569,761	559,862
Total stockholders' equity	286,907	199,262
Total liabilities and stockholders' equity	856,668	759,124
Consolidating Adjustments and Other
ASSETS
Accounts receivable, net of allowance	(330,240)	(278,562)
Prepaid expenses and other current assets	(5,702)	(6,477)
Total current assets	(335,942)	(285,039)
Non-current deferred tax assets	(379)	(321)
Other assets	(401,873)	(314,262)
Total assets	(738,194)	(599,622)
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	(335,908)	(285,039)
Total current liabilities	(335,908)	(285,039)
Long-term debt, net	(115,000)	(115,000)
Non-current deferred tax liabilities	(379)	(321)
Total liabilities	(451,287)	(400,360)
Total stockholders' equity	(286,907)	(199,262)
Total liabilities and stockholders' equity	$ (738,194)	$ (599,622)