Long-Term Equity Compensation (Weighted Average Grant Date Fair Value and Aggregate Intrinsic Value for RSU and PSU) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair values of RSUs and PSUs	$ 38.22
Restricted Stock Units and Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant-date fair values of RSUs and PSUs	$ 38.22	$ 30.65	$ 23.10
Aggregate intrinsic value of RSUs and PSUs vested	$ 49,000,000	$ 14,700,000	$ 18,000,000