Share Based Compensation - Summary of Stock Option Activity (Detail) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) $ / shares shares
Stockholders Equity Note [Abstract]
Number of Shares Outstanding, Beginning Balance | shares	13,861,000
Number of Shares Exercised | shares	121,000
Number of Shares Outstanding, Ending Balance | shares	13,740,000
Number of Shares Exercisable, Ending Balance | shares	10,255,000
Weighted Average Exercise Price Outstanding, Beginning Balance | $ / shares	$ 2.41
Weighted Average Exercise Price Exercised | $ / shares	2.23
Weighted Average Exercise Price Outstanding, Ending Balance | $ / shares	2.41
Weighted Average Exercise Price Exercisable, Ending Balance | $ / shares	$ 2.24
Weighted Average Remaining Contractual Term (Years) Outstanding, Ending Balance	6 years 4 months 24 days
Weighted Average Remaining Contractual Term (Years) Exercisable, Ending Balance	5 years 7 months 6 days
Aggregate Intrinsic Value Outstanding, Ending Balance | $	$ 3,532
Aggregate Intrinsic Value Exercisable, Ending Balance | $	$ 3,530