Debt (Summary of Debt Instruments) (Parenthetical) (Detail) In Millions, unless otherwise specified	1 Months Ended		12 Months Ended			1 Months Ended				12 Months Ended	1 Months Ended					1 Months Ended		1 Months Ended			12 Months Ended	1 Months Ended
	Mar. 31, 2012	Nov. 30, 2007	Dec. 31, 2012 USD ($) Installment	Dec. 31, 2012 RUB Installment	Dec. 31, 2012 Russian Fuel Card Company [Member] USD ($)	Feb. 04, 2013 Subsequent Event [Member]	Jun. 15, 2012 Subsequent Event [Member] Russian Fuel Card Company [Member] USD ($)	Dec. 31, 2012 Minimum [Member] Eurodollar Rate [Member]	Dec. 31, 2012 Maximum [Member] Eurodollar Rate [Member]	Dec. 31, 2012 Term Note Payable-Domestic, June 22, 2011 [Member] USD ($)	Nov. 06, 2012 Term Note Payable-Domestic, June 22, 2011 [Member] Term Loan [Member] USD ($)	Nov. 06, 2012 Term Note Payable-Domestic, June 22, 2011 [Member] Term Loan Facility [Member] USD ($)	Nov. 06, 2012 Term Note Payable-Domestic, June 22, 2011 [Member] Revolving Credit Facility [Member] USD ($)	Dec. 31, 2012 Term Note Payable-Domestic, June 22, 2011 [Member] Line of Credit [Member] USD ($)	Dec. 31, 2012 Term Note Payable-Domestic, June 22, 2011 [Member] Swing Line Loans [Member] USD ($)	Nov. 06, 2012 Term Note Payable-Domestic, June 22, 2011 [Member] Minimum [Member] USD ($)	Dec. 31, 2012 Term Note Payable-Domestic, June 22, 2011 [Member] Minimum [Member]	Nov. 06, 2012 Term Note Payable-Domestic, June 22, 2011 [Member] Maximum [Member] USD ($)	Dec. 31, 2012 Term Note Payable-Domestic, June 22, 2011 [Member] Maximum [Member]	Dec. 31, 2012 Amended And Restated [Member] Swing Line Loans [Member] USD ($)	Dec. 31, 2012 Commercial Paper [Member]	Feb. 04, 2013 Commercial Paper [Member] Subsequent Event [Member]
Debt Instrument [Line Items]
Line of credit facility, increase additional borrowings											$ 250					$ 150		$ 250
Increase borrowing limit on revolving line of credit												550	850	20	20	600		850		110
United Kingdom entities as designated borrowers	Two
Interest on the line of credit, sum of rate plus								1.25%	2.25%								0.25%		1.25%
Principal payment due		Nov. 01, 2010								Jun. 01, 2016
Principal payments on term loan										17.5
Current purchase limit under the securitization facility			500
Securitization facility termination date			Feb. 03, 2014	Feb. 03, 2014
Program fee rate																					0.24%	0.24%
Program fee variable rate																					0.75%	0.675%
Unused facility fee payable rate			0.35%	0.35%		0.30%
Deferred payment			11.3		11.3		11.3
Contingent earn-out payment			$ 3.9	120.6
Number of installments for earn out payments			2	2