Company Operations and Summary of Significant Accounting Policies - Basic and Diluted EPS (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Excluded from Computation of Earnings Per Share, Amount									1,000	1,100
Basic net income per share:
Net income	$ (377)	$ (762)	$ (8,931)	$ 3,991	$ 7,113	$ (5,767)	$ (6,908)	$ (1,512)	$ (6,079)	$ (7,074)	$ 7,390
Less: income allocated to participating securities											(17)
Net income allocated to common stockholders											$ 7,373
Weighted average common shares outstanding — basic									34,104	34,451	33,836
Net income per share — basic	$ (0.01)	$ (0.02)	$ (0.26)	$ 0.12	$ 0.21	$ (0.17)	$ (0.20)	$ (0.04)	$ (0.18)	$ (0.21)	$ 0.22
Diluted net income per share:
Net income	$ (377)	$ (762)	$ (8,931)	$ 3,991	$ 7,113	$ (5,767)	$ (6,908)	$ (1,512)	$ (6,079)	$ (7,074)	$ 7,390
Less: income allocated to participating securities											(16)
Net income allocated to common stockholders											$ 7,374
Weighted average common shares outstanding — basic									34,104	34,451	33,836
Dilutive securities											1,111
Weighted average common shares outstanding — diluted									34,104	34,451	34,947
Net income per share — diluted	$ (0.01)	$ (0.02)	$ (0.26)	$ 0.11	$ 0.20	$ (0.17)	$ (0.20)	$ (0.04)	$ (0.18)	$ (0.21)	$ 0.21
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount									1,900	1,000	500