Stock-Based Compensation Plans (Time-Based Restricted Stock Units) (Details) (Time-Based Restricted Stock [Member], USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Time-Based Restricted Stock [Member]
Non-vested, beginning balance, shares		1.6
Non-vested, beginning balance, weighted average fair value at date of grant		$ 13.04
Granted, shares	0.6
Granted, weighted average fair value at date of grant	$ 16.35
Vested, shares	(0.7)
Vested, weighted average fair value at date of grant	$ 12.75
Forfeited, shares	(0.1)
Forfeited, weighted average fair value at date of grant	$ 14.01
Non-vested, ending balance, shares	1.4	1.6
Non-vested, ending balance, weighted average fair value at date of grant	$ 14.62	$ 13.04