Share-Based Compensation (Summary of Restricted Stock and PSU Activity) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014
Restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Awards, Unvested balances	3,826,470
Number of Awards, Granted	953,178	[1]
Number of Awards, Vested	(1,337,866)
Number of Awards, Forfeited	(72,342)
Number of Awards, Unvested balances	3,369,440
Weighted-Average Grant Date Fair Value, Unvested balances	$ 25.96
Weighted-Average Grant Date Fair Value, Granted	$ 36.94
Weighted-Average Grant Date Fair Value, Vested	$ 22.60
Weighted-Average Grant Date Fair Value, Forfeited	$ 27.38
Weighted-Average Grant Date Fair Value, Unvested balances	$ 30.35
PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Awards, Unvested balances	1,915,601
Number of Awards, Granted	787,906	[2]
Number of Awards, Vested	(56,659)
Number of Awards, Forfeited	(77,344)
Number of Awards, Unvested balances	2,569,504
Weighted-Average Grant Date Fair Value, Unvested balances	$ 30.03
Weighted-Average Grant Date Fair Value, Granted	$ 40.31
Weighted-Average Grant Date Fair Value, Vested	$ 25.28
Weighted-Average Grant Date Fair Value, Forfeited	$ 27.16
Weighted-Average Grant Date Fair Value, Unvested balances	$ 33.37

[1] Primarily reflects our company-wide equity grant issued in March 2014, as discussed above.

[2] PSUs granted in 2014 reflect awards issued to certain officers, as described above.