Fair Value Measurements - Additional Information (Detail) (USD $) In Billions, unless otherwise specified	3 Months Ended	6 Months Ended
	Jun. 30, 2012 Cross Currency Swaps	Jun. 30, 2013 Cross Currency Swaps	Apr. 30, 2013 Interest Rate Swaps Matured
Derivatives, Fair Value [Line Items]
Notional amount of interest rate swaps matured			$ 1.25
Proceeds from other debt		1.6
Pre-tax gain (loss) recognized in other comprehensive income	$ (0.1)	$ (0.1)