Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2012

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of share-based compensation, stock options, activity

	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Terms (Years)	Aggregate Intrinsic Value
						(in millions)
Options outstanding at December 31, 2011	653,516		$	16.30
Granted	—		—
Exercised	(419,158	)	$	16.04
Cancelled	(373	)	14.47
Options outstanding at December 31, 2012	233,985		$	16.78	4.1	$4.5
Options exercisable:
December 31, 2011	223,016		$	16.42	2.1	$3.0
December 31, 2012	233,985		$	16.78	4.1	$4.5

Schedule of share-based compensation, restricted stock and restricted stock units activity

	Number of Restricted Share Awards		Weighted Average Fair Value per Award
Restricted share awards outstanding at December 31, 2011	3,062,661		$	27.39
Granted	1,067,105		29.44
Vested	(644,044	)	27.78
Forfeited	(184,351	)	30.30
Restricted share awards outstanding at December 31, 2012	3,301,371		$	27.82