Stock-based Compensation Stock-based Compensation (Details 3) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of awards vested	$ 15	$ 2,933
Total intrinsic value of options exercised	1,420	4,150
Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value per share (in dollars per share)	$ 24.10	$ 32.18
Total fair value of awards granted	51	186
Total fair value of awards vested	$ 340	$ 850