Income Taxes - Schedule of Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Unrecognized tax benefits, Beginning Balance	$ 1,462,000	$ 1,104,000	$ 946,000
Additions based on tax positions related to the current year	571,000	245,000	138,000
Additions for tax positions of prior years	43,000	120,000	29,000
Settlements			(1,000)
Lapse of statute	(6,000)	(7,000)	(8,000)
Unrecognized tax benefits, Ending Balance	$ 2,070,000	$ 1,462,000	$ 1,104,000