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	6 Months Ended
	Jun. 30, 2012
Time-Based Restricted Stock [Member]
Non-vested, beginning balance, shares	2.1
Non-vested, beginning balance, weighted average fair value at date of grant	$ 11.72
Granted, shares	0.9
Granted, weighted average fair value at date of grant	$ 12.93
Vested, shares	(1.0)
Vested, weighted average fair value at date of grant	$ 10.22
Forfeited, shares	(0.2)
Forfeited, weighted average fair value at date of grant	$ 13.01
Non-vested, ending balance, shares	1.8
Non-vested, ending balance, weighted average fair value at date of grant	$ 12.93