Share-Based Compensation (Summary of Stock Options Outstanding) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of shares vested and exercisable	391,618	375,375
Options vested and exercisable weighted average remaining contractual life	4 years 10 months 13 days	4 years 11 months 1 day
Options vested and exercisable weighted average exercise price	$ 8.44	$ 7.31
Options vested and exercisable intrinsic value	$ 7,609	$ 4,159
$4.81-$10.34
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range	$ 4.81
Range of exercise prices, upper range	$ 10.34
Number of shares vested and exercisable	298,960
Options vested and exercisable weighted average remaining contractual life	3 years 11 months 19 days
Options vested and exercisable weighted average exercise price	$ 7.29
Options vested and exercisable intrinsic value	6,153
$10.70-$12.25
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range	$ 10.70
Range of exercise prices, upper range	$ 12.25
Number of shares vested and exercisable	37,450
Options vested and exercisable weighted average remaining contractual life	7 years 2 months 1 day
Options vested and exercisable weighted average exercise price	$ 10.87
Options vested and exercisable intrinsic value	637
$12.98-$28.69
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range	$ 12.98
Range of exercise prices, upper range	$ 28.69
Number of shares vested and exercisable	55,208
Options vested and exercisable weighted average remaining contractual life	8 years 1 month 24 days
Options vested and exercisable weighted average exercise price	$ 13.03
Options vested and exercisable intrinsic value	819
$4.81-$6.47
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range		$ 4.81
Range of exercise prices, upper range		$ 6.47
Number of shares vested and exercisable		89,400
Options vested and exercisable weighted average remaining contractual life		2 years 8 months 5 days
Options vested and exercisable weighted average exercise price		$ 5.43
Options vested and exercisable intrinsic value		1,159
$6.81-$8.65
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range		$ 6.81
Range of exercise prices, upper range		$ 8.65
Number of shares vested and exercisable		219,675
Options vested and exercisable weighted average remaining contractual life		5 years 0 months 18 days
Options vested and exercisable weighted average exercise price		$ 7.19
Options vested and exercisable intrinsic value		2,462
$9.13-$14.01
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower range		$ 9.13
Range of exercise prices, upper range		$ 14.01
Number of shares vested and exercisable		66,300
Options vested and exercisable weighted average remaining contractual life		7 years 6 months 18 days
Options vested and exercisable weighted average exercise price		$ 10.29
Options vested and exercisable intrinsic value		$ 538