Acquisition - Purchase Price Allocations of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended	3 Months Ended
	Dec. 31, 2014	Mar. 31, 2015
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)		5 years 6 months
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