Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2014

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

Schedule of stock option activity

	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Terms (Years)	Aggregate Intrinsic Value
						(in millions)
Options outstanding at December 31, 2013	162,404		$	8.90	3.3	$3.0
Granted	—		—
Exercised	(67,111	)	$	8.95
Cancelled	—		—
Options outstanding at December 31, 2014	95,293		$	8.86	3.1	$1.8

Schedule of restricted stock activity

	Number of Restricted Share Awards		Weighted Average Grant-Date Fair Value per Award
Restricted share awards outstanding at December 31, 2013	7,810,104		$	16.50
Granted	2,364,839		32.35
Vested	(2,625,396	)	16.09
Forfeited	(136,578	)	22.05
Restricted share awards outstanding at December 31, 2014	7,412,969		$	21.60