Organization, Basis of Presentation and Summary of Significant Accounting Policies - Net Income (Loss) Per Share (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
Numerator:
Net loss available to common stockholders	$ (591)	$ (770)	$ (1,231)	$ (10)	$ 205	$ (1,142)	$ (5,695)	$ (5,167)	$ (2,602)	$ (11,799)	$ (27,953)
Denominator:
Weighted average shares outstanding - basic	45,860	46,160	46,257	45,501	45,053	41,225	38,518	37,714	45,946	40,649	36,982
Potential common shares - options (treasury stock method)									0	0	0
Weighted average shares outstanding - diluted	45,860	46,160	46,257	45,501	45,053	41,225	38,518	37,714	45,946	40,649	36,982
Shares excluded (anti-dilutive)									70	150	2
Shares excluded due to an exercise price greater than weighted average stock price for the period									1,132	1,511	2,150
Net loss per common share:
Basic	$ (0.01)	$ (0.02)	$ (0.03)	$ 0.00	$ 0.00	$ (0.03)	$ (0.15)	$ (0.14)	$ (0.06)	$ (0.29)	$ (0.76)
Diluted	$ (0.01)	$ (0.02)	$ (0.03)	$ 0.00	$ 0.00	$ (0.03)	$ (0.15)	$ (0.14)	$ (0.06)	$ (0.29)	$ (0.76)