Segment Information - Summary of Reconciliation of Segment EBITDA to Income before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Revenue	$ 782,810	$ 760,617
Segment EBITDA	132,849	136,003
Equity-based compensation expense	(4,979)	(6,101)
Transaction-related expenses	(3,549)	(4,321)
Interest expense, net	(42,785)	(48,130)
Depreciation and amortization	(41,680)	(40,580)
Income before income taxes	39,856	36,871
U.S. Facilities [Member]
Segment Reporting Information [Line Items]
Revenue	509,217	487,960
U.S. Facilities [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue	509,217	487,960
Segment EBITDA	120,074	119,008
U.K. Facilities [Member]
Segment Reporting Information [Line Items]
Revenue	273,593	272,657
U.K. Facilities [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue	273,593	272,657
Segment EBITDA	36,168	40,056
Corporate and Other [Member] \| Corporate Reconciling Items and Eliminations [Member]
Segment Reporting Information [Line Items]
Segment EBITDA	$ (23,393)	$ (23,061)

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

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