Share-Based Compensation - Additional Information (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of average closing price to be paid by employees			85.00%
Share-based compensation	$ 475	$ 415	$ 1,285	$ 1,101
Estimated pre-vesting forfeiture rate	5.00%
Weighted-average grant date fair value for stock options (in dollars per share)			$ 5.73	$ 3.97
Aggregate intrinsic value of stock options exercised			106	46
Cash receipts of stock options exercised			97	67
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock purchases through advance payroll deductions in a calendar year			25
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option term			10 years
Stock options vesting percentage			100.00%
Estimated pre-vesting forfeiture rate			4.73%
Unrecognized compensation expense	96		96
Unrecognized compensation expense expected recognition period			6 months 15 days
Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period			6 months
Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period			2 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period			3 years
Unrecognized compensation expense	2,523		2,523
Unrecognized compensation expense expected recognition period			1 year 5 months 9 days
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	0		0
Grant date fair value of ESPP options	$ 29