Share-Based Payments (Tables)

12 Months Ended

Dec. 31, 2013

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

Schedule of Weighted-Average Assumptions Used to Determine Fair Value of Stock Options

The fair values of the options granted during the years ended December 31, 2013, 2012, and 2011 have been estimated at the grant date using the Black-Scholes option-pricing model with the following weighted-average assumptions:

	For the Year Ended December 31,
	2013		2012		2011
Expected volatility	41.8	%	42.8	%	41.5	%
Risk-free interest rate	1.4	%	1.4	%	2.8	%
Expected life (years)	7.2		7.0		6.7
Dividend yield	0.0	%	0.0	%	0.0	%

Schedule of Stock Option Activity

A summary of our stock option activity and related information is as follows:

	Shares (In Thousands)		Weighted- Average Exercise Price per Share		Weighted- Average Remaining Life (Years)	Aggregate Intrinsic Value (In Millions)
Outstanding, December 31, 2012	2,575		$	21.12
Granted	141		24.17
Exercised	(338	)	24.39
Forfeitures	—		—
Expirations	(17	)	24.47
Outstanding, December 31, 2013	2,361		20.82		4.5	$	29.5
Exercisable, December 31, 2013	1,991		20.45		3.8	25.6

Schedule of Restricted Stock Activity

A summary of our issued restricted stock awards is as follows (share information in thousands):

	Shares		Weighted-Average Grant Date Fair Value
Nonvested shares at December 31, 2012	1,048		$	19.28
Granted	847		23.55
Vested	(690	)	18.25
Forfeited	(43	)	22.67
Nonvested shares at December 31, 2013	1,162		22.89