Debt - Additional Information (Detail) (USD $)		3 Months Ended	1 Months Ended	3 Months Ended	1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2013 Secured Debt	Feb. 29, 2012 LIBOR Plus A Margin Of 138 Basis Points	Mar. 31, 2012 LIBOR Plus A Margin Of 138 Basis Points	Feb. 29, 2012 LIBOR Plus A Margin Of 175 Basis Points	Mar. 31, 2012 LIBOR Plus A Margin Of 175 Basis Points	Dec. 31, 2012 One Point Three Eight Percentage Variable Rate Term Loan [Member]
Debt Disclosure [Line Items]
Term loan				$ 1,200,000,000		$ 200,000,000
Maturity date			Dec. 31, 2017		Dec. 31, 2017
Base points margin				1.38%		1.75%
Term loan issued, payments made							1,200,000,000
Receivable securitization facility, borrowed amount		260,000,000
Repayments of Secured Debt		200,000,000
Receivable securitization facility, interest rate		0.95%
Debt and capital lease obligations	10,200,000,000
Debt fair value	$ 12,200,000,000