Condensed Consolidating Balance Sheet (Unaudited) (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
ASSETS
Cash and cash equivalents	$ 56,400	$ 52,183	$ 43,164	$ 37,711
Accounts receivable, net of allowance	212,634	254,188
Prepaid expenses and other current assets	19,566	21,119
Total current assets	288,600	327,490
Property and equipment, net	2,825,203	2,802,449
Goodwill	44,779	40,927
Non-current deferred tax assets	11,194	12,814
Other assets	94,674	88,718
Total assets	3,264,450	3,272,398
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	269,458	277,804
Income taxes payable	3,957	3,034
Current portion of long-term debt	12,429	10,000
Total current liabilities	285,844	290,838
Long-term debt, net	1,455,265	1,437,187
Deferred revenue	36,327	39,735
Other liabilities	52,804	53,030
Total liabilities	1,830,240	1,820,790
Total stockholders' equity	1,434,210	1,451,608	$ 1,463,161	$ 1,458,963
Total liabilities and stockholders' equity	3,264,450	3,272,398
Reportable Legal Entities | Parent
ASSETS
Cash and cash equivalents	35,420	25,745
Accounts receivable, net of allowance	160,505	211,673
Prepaid expenses and other current assets	2,803	1,835
Total current assets	198,728	239,253
Property and equipment, net	2,494,590	2,467,166
Goodwill	33,057	26,031
Other assets	460,517	421,474
Total assets	3,186,892	3,153,924
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	274,701	251,011
Income taxes payable	1,734	1,443
Current portion of long-term debt	12,429	10,000
Total current liabilities	288,864	262,454
Long-term debt, net	1,456,572	1,437,982
Non-current deferred tax liabilities	474	379
Other liabilities	6,772	1,501
Total liabilities	1,752,682	1,702,316
Total stockholders' equity	1,434,210	1,451,608
Total liabilities and stockholders' equity	3,186,892	3,153,924
Reportable Legal Entities | Combined Subsidiary Guarantors
ASSETS
Cash and cash equivalents	20,980	26,438
Accounts receivable, net of allowance	402,926	372,755
Prepaid expenses and other current assets	22,512	24,986
Total current assets	446,418	424,179
Property and equipment, net	330,577	335,283
Goodwill	11,722	14,896
Non-current deferred tax assets	11,668	13,193
Other assets	52,047	69,117
Total assets	852,432	856,668
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	348,636	362,701
Income taxes payable	2,223	1,591
Total current liabilities	350,859	364,292
Long-term debt, net	114,261	114,205
Deferred revenue	36,327	39,735
Other liabilities	46,032	51,529
Total liabilities	547,479	569,761
Total stockholders' equity	304,953	286,907
Total liabilities and stockholders' equity	852,432	856,668
Consolidating Adjustments and Other
ASSETS
Accounts receivable, net of allowance	(350,797)	(330,240)
Prepaid expenses and other current assets	(5,749)	(5,702)
Total current assets	(356,546)	(335,942)
Property and equipment, net	36
Non-current deferred tax assets	(474)	(379)
Other assets	(417,890)	(401,873)
Total assets	(774,874)	(738,194)
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	(353,879)	(335,908)
Total current liabilities	(353,879)	(335,908)
Long-term debt, net	(115,568)	(115,000)
Non-current deferred tax liabilities	(474)	(379)
Total liabilities	(469,921)	(451,287)
Total stockholders' equity	(304,953)	(286,907)
Total liabilities and stockholders' equity	$ (774,874)	$ (738,194)