Acquisition - Summary of Preliminary Estimated Fair Value of Intangible Assets Acquired and the Related Estimated Useful Lives (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Comdata Inc. [Member]
Business Acquisition [Line Items]
Intangible assets		$ 1,630,700
Comdata Inc. [Member] | Trade Names And Trademarks Indefinite Lived [Member]
Business Acquisition [Line Items]
Intangible assets		237,100
Other Acquisitions [Member]
Business Acquisition [Line Items]
Intangible assets		47,992
Other Acquisitions [Member] | Trade Names And Trademarks Indefinite Lived [Member]
Business Acquisition [Line Items]
Intangible assets		$ 2,900
Customer Relationships [Member] | Comdata Inc. [Member]
Business Acquisition [Line Items]
Useful Lives (in Years)		19 years
Intangible assets		$ 1,269,700
Customer Relationships [Member] | Other Acquisitions [Member]
Business Acquisition [Line Items]
Useful Lives (in Years)		8 years
Intangible assets		$ 15,592
Software [Member]
Business Acquisition [Line Items]
Useful Lives (in Years)	5 years 1 month 6 days
Software [Member] | Comdata Inc. [Member]
Business Acquisition [Line Items]
Intangible assets		$ 123,300
Software [Member] | Comdata Inc. [Member] | Minimum [Member]
Business Acquisition [Line Items]
Useful Lives (in Years)		4 years
Software [Member] | Comdata Inc. [Member] | Maximum [Member]
Business Acquisition [Line Items]
Useful Lives (in Years)		7 years
Non-compete [Member]
Business Acquisition [Line Items]
Useful Lives (in Years)	6 years
Non-compete [Member] | Comdata Inc. [Member]
Business Acquisition [Line Items]
Useful Lives (in Years)		3 years
Intangible assets		$ 600
Franchisee Agreement [Member] | Other Acquisitions [Member]
Business Acquisition [Line Items]
Useful Lives (in Years)		20 years
Intangible assets		$ 29,500