Share-Based Compensation Plans (Options) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013 Installments	Dec. 31, 2012 Installments	Dec. 31, 2011
Unrecognized Compensation Cost [Abstract]
Employee Stock Purchase Plan Percent of Stock Price At Closing Date	85.00%
Employee Stock Option [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	3,000
Award vesting period	10 years	10 years
Estimated value of options granted during period	$ 11,700,000	$ 9,300,000	$ 11,200,000
Number of Shares
Options outstanding at December 31, 2012	3,765,000
Options granted	445,705	581,265	683,580
Options exercised	(1,300,000)
Options canceled	(247,000)
Options outstanding at December 31, 2013	2,664,000	3,765,000
Options vested and expected to vest at December 31, 2013	2,628,000
Options exercisable at December 31, 2013	1,583,000
Weighted Average Exercise Price
Options outstanding at December 31, 2012	$ 20.18
Options granted	$ 26.18
Options exercised	$ 20.49
Options canceled	$ 19.20
Options outstanding at December 31, 2013	$ 21.12	$ 20.18
Options vested and expected to vest at December 31, 2013	$ 21.10
Options exercisable at December 31, 2013	$ 21.72
Weighted Average Remaining Contractual Term
Options Outstanding, Weighted Average Remaining Contractual Term (in years)	5 years 5 months 12 days
Option Exercisable, Weighted Average Remaining Contractual Term (in years)	3 years 7 months 20 days
Aggregate Intrinsic Value
Options Outstanding, Intrinsic Value	38,373,000
Options, Vested and Expected to Vest, Aggregate Intrinsic Value	32,147,000
Options Exercisable, Intrinsic Value	16,073,000
Unrecognized Compensation Cost [Abstract]
Unrecognized compensation costs related to restricted stock units	4,700,000
Total compensation cost not yet recognized, period for recognition (years)	1 year 9 months 3 days
Total intrinsic value of options exercised	$ 13,800,000	$ 3,700,000	$ 500,000