Equity-Based Compensation - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 EquityPlan	Mar. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average estimated fair value of employee stock options and SAR granted and RSU granted	$ 4.30	$ 2.36
Number of equity incentive plans	5
Number of employee stock purchase plan	1
Common stock available for grant under the Company's employee stock purchase plan	398,000
Common stock available for grant under the Company's equity incentive plans	291,420
Additional information about stock options and SARs and RSUs outstanding and exercisable	$ 8.07
Aggregate equity-based compensation expenses	$ 1,043	$ 1,486
Total unrecognized compensation expense related to unvested equity-based compensation awards	$ 4,686
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life	4 years 6 months 11 days	4 years 1 month 21 days