Summary of Changes in Allowance For Doubtful Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Balance at beginning of period	$ 1,460	$ 1,513
Additions (reductions) to expense	1,497	(23)
Write-offs, net of recoveries and other adjustments	(145)	(30)
Balance at end of period	$ 2,812	$ 1,460