Income Taxes - Summary of Valuation Allowance (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Valuation Allowance [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 11,083	$ 11,959	$ 12,028	$ 7,798
Additions charged to income taxes expense	0	497	6,592
Deductions	$ (876)	$ (566)	$ (2,362)