Stock-Based Compensation - Restricted Stock Activity Rollforward (Details) (Restricted Stock, USD $)	12 Months Ended
	Dec. 31, 2014
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Restricted stock, beginning of year, number of shares	225,525
Granted, number of shares	148,278
Vested, number of shares	(96,143)
Forfeited, number of shares	(27,772)
Canceled, number of shares	(1,489)
Restricted stock, end of year, number of shares	248,399
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Restricted stock, beginning of year, weighted-average measurement date fair value	$ 16.08
Granted, weighted average grant date fair value	$ 24.36
Vested, weighted average grant date fair value	$ 15.54
Forfeited, weighted average grant date fair value	$ 16.43
Cancelled, weighted average grant date fair value	$ 21.39
Restricted stock, end of year, weighted-average measurement date fair value	$ 21.16