Stock Benefit Plans and Stock-Based Compensation - Summary of Information about Restricted Stock Awards Activity (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Unvested beginning balance	361
Shares, Awarded	702
Shares, Vested	(77)
Shares, Forfeited	(109)
Shares, Unvested ending balance	877	361
Weighted average grant date fair value, Unvested beginning balance	$ 2.61
Weighted average grant date fair value, Awarded	$ 1.57
Weighted average grant date fair value, Vested	$ 2.95
Weighted average grant date fair value, Forfeited	$ 2.10
Weighted average grant date fair value, Unvested ending balance	$ 1.81	$ 2.61
Weighted average remaining recognition period (in years), Unvested beginning balance	1 year 5 months 27 days	3 years 2 months 19 days