Common Stock (Schedule of Stock Option Activity) (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Equity and Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Weighted Average Exercise Price $ 19.99    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]      
Outstanding at beginning of period 875 1,288 1,536
Granted 0 74 1,148
Exercised (213) (484) (1,362)
Canceled (10) (3) (34)
Outstanding at end of period 652 875 1,288
Exercisable 564 684 770
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]      
Outstanding at beginning of period $ 17.85 $ 13.69 $ 9.30
Granted $ 0.00 $ 53.78 $ 22.17
Exercised $ 11.21 $ 12.22 $ 15.42
Canceled $ 19.98 $ 23.63 $ 32.26
Outstanding at end of period $ 19.99 $ 17.85 $ 13.69
Exercisable $ 16.18 $ 11.67 $ 10.97