Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
ASSETS
Cash and cash equivalents	$ 42,735	$ 37,711	$ 42,731	$ 65,291
Accounts receivable, net of allowance	241,143	229,885
Prepaid expenses and other current assets	20,178	31,228
Total current assets	304,056	298,824
Property and equipment, net	2,799,476	2,837,657
Goodwill	38,728	38,386
Non-current deferred tax assets	15,460	13,735
Other assets	85,046	83,002
Total assets	3,242,766	3,271,604
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	266,405	260,107
Income taxes payable	1,168	2,086
Current portion of long-term debt	10,000	10,000
Total current liabilities	277,573	272,193
Long-term debt, net	1,411,210	1,435,169
Deferred revenue	43,143	53,437
Other liabilities	52,159	51,842
Total liabilities	1,784,085	1,812,641
Total stockholders' equity	1,458,681	1,458,963	$ 1,444,193	$ 1,462,748
Total liabilities and stockholders' equity	3,242,766	3,271,604
Reportable Legal Entities | Parent
ASSETS
Cash and cash equivalents	20,122	11,378
Accounts receivable, net of allowance	190,866	237,495
Prepaid expenses and other current assets	2,583	7,582
Total current assets	213,571	256,455
Property and equipment, net	2,477,110	2,493,025
Goodwill	23,832	23,231
Other assets	405,683	339,391
Total assets	3,120,196	3,112,102
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	235,716	203,074
Income taxes payable	1,945	1,850
Current portion of long-term debt	10,000	10,000
Total current liabilities	247,661	214,924
Long-term debt, net	1,412,060	1,436,186
Non-current deferred tax liabilities	495	321
Other liabilities	1,299	1,708
Total liabilities	1,661,515	1,653,139
Total stockholders' equity	1,458,681	1,458,963
Total liabilities and stockholders' equity	3,120,196	3,112,102
Reportable Legal Entities | Combined Subsidiary Guarantors
ASSETS
Cash and cash equivalents	22,613	26,333
Accounts receivable, net of allowance	347,066	270,952
Prepaid expenses and other current assets	23,597	30,123
Total current assets	393,276	327,408
Property and equipment, net	322,366	344,632
Goodwill	14,896	15,155
Non-current deferred tax assets	15,955	14,056
Other assets	64,472	57,873
Total assets	810,965	759,124
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	333,480	342,072
Income taxes payable	(777)	236
Total current liabilities	332,703	342,308
Long-term debt, net	114,150	113,983
Deferred revenue	43,143	53,437
Other liabilities	50,860	50,134
Total liabilities	540,856	559,862
Total stockholders' equity	270,109	199,262
Total liabilities and stockholders' equity	810,965	759,124
Consolidating Adjustments and Other
ASSETS
Accounts receivable, net of allowance	(296,789)	(278,562)
Prepaid expenses and other current assets	(6,002)	(6,477)
Total current assets	(302,791)	(285,039)
Non-current deferred tax assets	(495)	(321)
Other assets	(385,109)	(314,262)
Total assets	(688,395)	(599,622)
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	(302,791)	(285,039)
Total current liabilities	(302,791)	(285,039)
Long-term debt, net	(115,000)	(115,000)
Non-current deferred tax liabilities	(495)	(321)
Total liabilities	(418,286)	(400,360)
Total stockholders' equity	(270,109)	(199,262)
Total liabilities and stockholders' equity	$ (688,395)	$ (599,622)