Income Taxes - Components of Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax assets:
Acquisition and debt related costs	$ 5,557	$ 15,899
Net operating losses	201,604	294,986
Goodwill impairment	54,207
Self-insurance	6,992	9,766
Deferred revenue	2,627	4,696
Cash flow hedge	2,282	9,114
Restricted stock	4,097	3,374
Tax credits	7,922	6,882
Other	7,263	9,165
Total deferred income tax assets	292,551	353,882
Valuation allowance	(2,762)	(584)
Net deferred tax assets	289,789	353,298
Deferred income tax liabilities:
Property and equipment	(201,019)	(326,320)
Amortization - Goodwill	(37,291)	(49,493)
Amortization - Other Intangibles	(15,193)	(20,877)
Other	(3,466)	(4,527)
Total deferred income tax liabilities	(256,969)	(401,217)
Net deferred income tax assets	$ 32,820
Net deferred income tax (liabilities)		$ (47,919)