Shareholders' Equity - Summary of Stock Option Activity (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Shares, Beginning Balance	1,515,621
Granted at fair value, Number of Shares	330,850
Exercised, Number of Shares	(123,613)
Forfeited, Number of Shares	(12,959)
Expired, Number of Shares	(57,032)
Number of Shares, Ending Balance	1,652,867
Vested and expected to vest, Number of Shares, Ending Balance	1,561,427
Exercisable, Number of Shares, Ending Balance	983,478
Weighted Average Exercise Price, Beginning Balance	$ 3.36
Granted at fair value, Weighted Average Exercise Price	$ 3.32
Exercised, Weighted Average Exercise Price	$ 2.48
Forfeited, Weighted Average Exercise Price	$ 3.64
Expired, Weighted Average Exercise Price	$ 5.92
Weighted Average Exercise Price, Ending Balance	$ 3.33
Vested and expected to vest, Weighted Average Exercise Price, Ending Balance	$ 3.33
Exercisable, Weighted Average Exercise Price, Ending Balance	$ 3.30
Weighted Average Remaining Contractual Life (in years)	4 years 10 months 28 days
Vested and expected to vest, Weighted Average Remaining Contractual Life (in years)	4 years 8 months 9 days
Exercisable, Weighted Average Remaining Contractual Life (in years)	2 years 6 months 26 days
Aggregate Intrinsic Value	$ 444,091
Vested and expected to vest, Aggregate Intrinsic Value	444,151
Exercisable, Aggregate Intrinsic Value	$ 398,709