Stockholders' Equity (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Stock-Based Compensation
Stock-based compensation (in dollars)	$ 1,120	$ 1,003
Stock options
Number of Shares
Balance at the beginning of the period (in shares)	3,250,852
Granted (in shares)	377,786
Canceled (in shares)	(22,871)
Exercised (in shares)	(25,616)
Balance at the end of the period (in shares)	3,580,151
Weighted Average Exercise Price
Balance at the beginning of the period (in dollars per share)	$ 6.40
Granted (in dollars per share)	$ 10.33
Cancelled (in dollars per share)	$ 15.16
Exercised (in dollars per share)	$ 4.43
Balance at the end of the period (in dollars per share)	$ 6.77
RSUs
Number of Shares
Balance at the beginning of the period (in shares)	864,634
Granted (in shares)	229,092
Forfeited (in shares)	(3,500)
Vested (in shares)	(358,115)
Balance at the end of the period (in shares)	732,111
Weighted Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per shares)	$ 3.68
Granted (in dollars per share)	$ 10.34
Forfeited (in dollars per share)	$ 8.61
Vested (in dollars per share)	$ 3.12
Balance at the end of the period (in dollars per shares)	$ 6.66
Performance share units
Number of Shares
Balance at the beginning of the period (in shares)	284,423
Granted (in shares)	0
Forfeited (in shares)	0
Vested (in shares)	0
Balance at the end of the period (in shares)	284,423
Weighted Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per shares)	$ 8.68
Balance at the end of the period (in dollars per shares)	$ 8.68
Stock-Based Compensation
Stock-based compensation (in dollars)	$ 0