Reconciliation of Shares Used to Determine Net Income per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Earnings Per Share Disclosure [Line Items]
Net Income	$ 334	$ 5,135	$ 4,803	$ 7,644
Weighted average number of shares - basic	24,891,115	23,841,996	24,605,541	23,813,776
Weighted average number of shares outstanding - diluted	26,859,009	26,177,960	26,670,232	26,149,740
Warrants
Earnings Per Share Disclosure [Line Items]
Weighted average number of shares underlying	383,123	277,867	432,705	277,867
Options
Earnings Per Share Disclosure [Line Items]
Weighted average number of shares underlying	1,584,771	2,058,097	1,631,986	2,058,097