Share-Based Compensation (Details 2) - Restricted Stock (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended				1 Months Ended			12 Months Ended
	Dec. 31, 2013 RSUs and RSAs		Dec. 31, 2012 RSUs and RSAs	Dec. 31, 2011 RSUs and RSAs	Feb. 28, 2009 RSUs Granted in February 2009 Performance-vesting, dependent on the company's TSR compared to other companies in the Russell 2000 Index	Feb. 28, 2009 RSUs Granted in February 2009 Performance-vesting, dependent on the company's TSR for a 3-yr performance period as compared to other companies in the Russell 2000 Index	Feb. 28, 2009 RSUs Granted in February 2009 Performance-vesting, dependent on the company's TSR for a 5-yr performance period as compared to other companies in the Russell 2000 Index	Dec. 31, 2013 RSUs Granted in 2013	Dec. 31, 2013 RSUs Granted in 2013 Service-vesting, ratably over 4-yr service-period installments	Dec. 31, 2013 RSUs Granted in 2013 Market-vesting
Restricted Stock Roll Forward
Number of units or shares outstanding, beginning of year	2,800,230
Number of units or shares granted	1,542,948				2,000,000	1,050,000	950,000	1,542,948	1,206,144	336,804
Number of units or shares released	(588,550)
Number of units or shares cancelled	(216,357)
Number of units or shares outstanding, end of year	3,538,271		2,800,230
Restricted Stock, Weighted-Average Grant-Date Fair Value
Weighted-average grant-date fair value of units or shares outstanding, beginning of year	$ 25.57
Weighted-average grant-date fair value of units or shares granted	$ 39.24		$ 51.78	$ 36.22
Weighted-average grant-date fair value of units or shares released	$ 35.43
Weighted-average grant-date fair value of units or shares cancelled	$ 42.23
Weighted-average grant-date fair value of units or shares outstanding, end of year	$ 28.79		$ 25.57
Restricted Stock, Additional Disclosures
Number of units or shares expected to vest after December 31, 2013	3,106,300	[1]
Weighted-average grant-date fair value of units or shares expected to vest after December 31, 2013	$ 29.78	[1]
Pre-tax intrinsic value of the RSUs and RSAs released	$ 29.7		$ 75.5	$ 7.7
Vesting period						3 years	5 years		4 years	3 years
Grant-date fair value of awards					$ 7.0
Number of equal installments in which awards vest									4

[1] Includes reduction of shares outstanding due to estimated forfeitures