Acquisitions - Summary of Purchase Price Allocation (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 26, 2017	Aug. 09, 2017	Dec. 31, 2016	Aug. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 4,715,823			$ 4,195,150		$ 3,546,034
Cambridge
Business Acquisition [Line Items]
Restricted cash			$ 37,666
Trade and other receivables			61,801
Prepaid expenses and other			15,190
Property and equipment			7,106
Other long term assets			10,025
Goodwill			500,391
Customer relationships and other identifiable intangible assets			271,793
Liabilities assumed			(194,552)
Deferred tax liabilities			(93,364)
Aggregate purchase price			$ 616,056
Creative Lodging Solutions
Business Acquisition [Line Items]
Trade and other receivables		$ 37,986
Prepaid expenses and other		1,426
Property and equipment		5,745
Other long term assets		53,259
Goodwill		55,711
Liabilities assumed		(32,202)
Deferred tax liabilities		(17,217)
Aggregate purchase price		$ 104,708
Servicos e Technologia de Pagamentos S.A.
Business Acquisition [Line Items]
Trade and other receivables					$ 243,157
Prepaid expenses and other					5,757
Deferred tax assets					20,644
Property and equipment					44,226
Other long term assets					14,280
Goodwill					663,040
Customer relationships and other identifiable intangible assets					548,682
Liabilities assumed					(312,297)
Aggregate purchase price					$ 1,227,489
Series of Individually Immaterial Business Acquisitions
Business Acquisition [Line Items]
Trade and other receivables				27,810
Prepaid expenses and other				5,097
Deferred tax assets				146
Property and equipment				992
Goodwill				28,540
Customer relationships and other identifiable intangible assets				61,823
Liabilities assumed				(42,550)
Deferred tax liabilities				(5,123)
Aggregate purchase price				$ 76,735
2015 Acquisitions
Business Acquisition [Line Items]
Trade and other receivables						521
Prepaid expenses and other						996
Property and equipment						197
Goodwill						9,561
Customer relationships and other identifiable intangible assets						39,791
Liabilities assumed						(2,331)
Deferred tax liabilities						(2,437)
Aggregate purchase price						$ 46,298