Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable - Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 351	$ 303	$ 357
Additions- Charges to (Recovery of) Costs and Expenses	175	124	(54)
Deductions- Write- offs/Costs Incurred	265	76	0
Balance at End of Year	261	351	303
Deferred Tax Assets - Valuation Allowance [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	45,626	26,920	13,128
Additions- Charges to (Recovery of) Costs and Expenses	8,279	21,042	13,792
Deductions- Write- offs/Costs Incurred	2,316	2,336	0
Balance at End of Year	$ 51,589	$ 45,626	$ 26,920