Employee Stock Purchase Plan Stock Options and Warrants - Options Outstanding (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise	$ 9.58
Range of Exercise	$ 15.12
Number Outstanding	3,008
Number Exercisable	2,075
$7.65 - $9.70
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise	$ 9.58
Range of Exercise	$ 11.05
Number Outstanding	764
Weighted Average Remaining Contractual Life (in years)	1 year 11 months 5 days
Weighted Average Exercise Price	$ 9.96
Number Exercisable	639
Weighted Average Exercise Price	$ 9.97
$9.71 - $11.53
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise	$ 11.41
Range of Exercise	$ 12.02
Number Outstanding	859
Weighted Average Remaining Contractual Life (in years)	1 year 3 months 0 days
Weighted Average Exercise Price	$ 11.68
Number Exercisable	859
Weighted Average Exercise Price	$ 11.68
$12.02 - $13.75
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise	$ 12.1
Range of Exercise	$ 13.75
Number Outstanding	1,094
Weighted Average Remaining Contractual Life (in years)	4 years 10 months 24 days
Weighted Average Exercise Price	$ 13.53
Number Exercisable	367
Weighted Average Exercise Price	$ 13.60
$13.82 - $17.34
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise	$ 13.77
Range of Exercise	$ 15.12
Number Outstanding	291
Weighted Average Remaining Contractual Life (in years)	3 years 0 months 0 days
Weighted Average Exercise Price	$ 14.03
Number Exercisable	210
Weighted Average Exercise Price	$ 14.08