Share-Based Compensation Plans (Options) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Net income	$ 128,996	$ 74,467	$ 107,675
Employee Stock Option [Member]
Number of Shares
Options outstanding, beginning balance	2,563,000
Options granted	0	290,737	445,705
Options exercised	(695,000)
Options canceled	(42,000)
Options outstanding, ending balance	1,826,000	2,563,000
Options vested and expected to vest	1,818,000
Options exercisable	1,579,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Options outstanding, beginning balance	$ 21.33	$ 22.32
Options granted	0.00
Options exercised	24.53
Options canceled	28.62
Options outstanding, ending balance	21.33	$ 22.32
Options vested and expected to vest	21.30
Options exercisable	$ 20.09
Options outstanding, Weighted Average Remaining Contractual Term	5 years 1 month 2 days
Options outstanding, Aggregate Intrinsic Value	$ 22,867
Options vested and expected to vest, Weighted Average Remaining Contractual Term	4 years 12 months 28 days
Options vested and expected to vest, Aggregate Intrinsic Value	$ 22,849
Options exercisable, Weighted Average Remaining Contractual Term	4 years 8 months 2 days
Options exercisable, Aggregate Intrinsic Value	$ 21,756