Long-term Debt - Derivative (Details) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Oct. 25, 2012 Interest Rate Swap	Oct. 25, 2012 Amended and Restated Term Loan Interest Rate Swap Cash Flow Hedging	Dec. 31, 2012 Significant Other Observable Inputs (Level 2) Fair Value, Measurements, Recurring
Derivative
Notional amount of interest rate derivatives					$ 1,500,000,000
Derivative, Description of Variable Rate Basis				one-month LIBOR
Derivative, fixed interest rate					1.46%
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred	3,000,000
Unrealized loss on derivatives arising during period, net of tax	2,000,000	0	0
Derivative financial instruments						$ 4,000,000