Shareholders' Equity - Summary of Stock Option (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Beginning balance of outstanding shares	410	507	655
Forfeitures, Shares	(71)	(31)	(132)
Granted, Shares	1,215
Exercised, Shares		(66)	(16)
Ending balance of outstanding, shares	1,554	410	507	655
Exercisable, Shares	330	355	402
Beginning Balance of Outstanding Weighted Average Exercise Price	$ 11.45	$ 10.43	$ 10.53
Forfeitures, Weighted Average Exercise Price	10.86	6.84	11.53
Granted, Weighted Average Exercise Price	11.06
Exercised, Weighted Average Exercise Price		4.10	5.55
Ending Balance of Outstanding Weighted Average Exercise Price	11.17	11.45	10.43	$ 10.53
Exercisable, Weighted Average Exercise Price	$ 11.66	$ 12.08	$ 10.52
Outstanding, Weighted Average Remaining Contractual Term	5 years 9 months 18 days	4 years 8 months 12 days	5 years 2 months 12 days	6 years
Exercisable, Weighted Average Remaining Contractual Term	3 years	4 years 7 months 6 days	4 years 7 months 6 days
Outstanding, Aggregate Intrinsic Value	$ 195	$ 32	$ 186
Exercisable, Aggregate Intrinsic Value	$ 6	$ 29	$ 186