Stock-Based Compensation (Options) (Details) (Stock Options [Member], USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Stock Options [Member]
Aggregate Intrinsic Value
Options outstanding, Aggregate Intrinsic Value	$ 30,492
Options vested and expected to vest, Aggregate Intrinsic Value	30,403
Options exercisable, Aggregate Intrinsic Value	$ 28,737
Number of Shares
Options outstanding, beginning balance	2,562,000
Options granted	0	242,687
Options exercised	203,000
Options canceled	5,000
Options outstanding, ending balance	2,354,000
Options vested and expected to vest, outstanding	2,337,000
Options exercisable, end of period	2,061,000
Weighted Average Exercise Price
Options outstanding, Weighted Average Exercise Price, beginning balance	$ 22.32
Options granted, Weighted Average Exercise Price	$ 0.00
Options exercised, Weighted Average Exercise Price	$ 22.24
Options canceled, Weighted Average Exercise Price	$ 28.35
Options outstanding, Weighted Average Exercise Price, ending balance	$ 22.31
Options vested and expected to vest, Weighted Average Exercise Price	$ 22.26
Options exercisable, Weighted Average Exercise Price, end of period	$ 21.33
Weighted Average Remaining Contractual Term
Options outstanding, Weighted Average Remaining Contractual Term (in years)	5 years
Options vested and expected to vest, Weighted Average Remaining Contractual Term (in years)	4 years 11 months 6 days
Option exercisable, Weighted Average Remaining Contractual Term (in years)	4 years 5 months 12 days