Share-Based Compensation Plans (Options) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012 years Installments Y	Dec. 31, 2011	Dec. 31, 2010
Number of Shares
Options outstanding at December 31, 2012	3,765,000
Unrecognized Compensation Cost [Abstract]
Employee Stock Purchase Plan Percent of Stock Price At Closing Date	85.00%
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of annual installments in which stock options will vest	3
Estimated value of options granted during period	$ 9,300,000	$ 11,200,000	$ 20,600,000
Number of Shares
Options outstanding at December 31, 2011	4,601,000
Options granted	581,265	683,580	1,098,519
Options exercised	(744,000)
Options canceled	(673,000)
Options outstanding at December 31, 2012		4,601,000
Options vested and expected to vest at December 31, 2012	3,726,000
Options exercisable at December 31, 2012	2,242,000
Weighted Average Exercise Price
Options outstanding at December 31, 2011	$ 20.78
Options granted	$ 16.00
Options exercised	$ 18.99
Options canceled	$ 21.55
Options outstanding at December 31, 2012	$ 20.18	$ 20.78
Options vested and expected to vest at December 31, 2012	$ 20.22
Options exercisable at December 31, 2012	$ 22.33
Weighted Average Remaining Contractual Term
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	5.4
Options, Vested and Expected to Vest, Weighted Average Remaining Contractual Term (in years)	5.4
Option Exercisable, Weighted Average Remaining Contractual Term (in years)	3.6
Aggregate Intrinsic Value
Options Outstanding, Intrinsic Value	25,422,000
Options, Vested and Expected to Vest, Aggregate Intrinsic Value	25,007,000
Options Exercisable, Intrinsic Value	10,337,000
Unrecognized Compensation Cost [Abstract]
Unrecognized compensation costs related to restricted stock units	3,600,000
Total compensation cost not yet recognized, period for recognition (years)	1.8
Total intrinsic value of options exercised	$ 3,700,000	$ 500,000	$ 6,100,000