Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands				12 Months Ended
		Aug. 09, 2017	Aug. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Purchase price, net of cash acquired	[1]			$ 705,257	$ 1,331,985	$ 49,069
Cash acquired				51,300
Deferred payments of previous acquisitions					6,100
Payments for other investing activities				38,953	(1,411)	8,470
Equity method investments				32,859	36,200
Aggregate purchase price						46,300
Issuance of new debt in acquisition				29,341	0	0
Shell
Business Acquisition [Line Items]
Cash acquired					11,100
Aggregate purchase price					76,700
Masternaut Group Holdings Limited
Business Acquisition [Line Items]
Equity method investments					7,900	8,400
Return on equity method investment					9,200
2017 Acquisitions
Business Acquisition [Line Items]
Cash acquired				96,200
Aggregate purchase price				720,800
Issuance of new debt in acquisition				29,300
Cambridge
Business Acquisition [Line Items]
Cash acquired		$ 94,500
Aggregate purchase price		616,100
Issuance of new debt in acquisition		23,800
Creative Lodging Solutions
Business Acquisition [Line Items]
Cash acquired				1,800
Aggregate purchase price				104,700
Issuance of new debt in acquisition				5,500
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Intangible assets					61,823
Servicos e Technologia de Pagamentos S.A.
Business Acquisition [Line Items]
Cash acquired			$ 40,200
Aggregate purchase price			1,230,000
Intangible assets			548,682
Liabilities arising from contingencies			15,100
Indemnification assets			$ 15,100
2014 Acquisition
Business Acquisition [Line Items]
Deferred payments of previous acquisitions						$ 3,400
Non-compete agreements | Cambridge
Business Acquisition [Line Items]
Intangible assets		$ 5,800
Non-compete agreements | Creative Lodging Solutions
Business Acquisition [Line Items]
Intangible assets				$ 4,500
Non-compete agreements | Servicos e Technologia de Pagamentos S.A.
Business Acquisition [Line Items]
Intangible assets					$ 23,200

[1] Amounts reported in acquisitions and investment, net of cash acquired, includes debt assumed and immediately repaid in acquisitions.