Computation of Basic and Diluted Earnings 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
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net (loss) income	$ (3,142)	$ 5,796	$ (6,311)	$ 7,178
Net (loss) income allocable to common shareholders (A)	(3,404)	5,562	(6,835)	6,710
Weighted average outstanding shares of common stock (B)	18,905,842	15,778,678	17,825,311	14,087,522
Dilutive effect of convertible preferred stock, employee stock options and warrants		199		118
Common stock and common stock equivalents (C)	18,905,842	15,977,939	17,825,311	14,205,583
(Loss) income per common share:
Basic (A/B)	$ (0.18)	$ 0.35	$ (0.38)	$ 0.48
Diluted (A/C)	$ (0.18)	$ 0.35	$ (0.38)	$ 0.47
Dividend Undeclared
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Accumulated undeclared dividends on preferred stock	$ (262)	$ (234)	$ (524)	$ (468)