Financial Instruments (Available-for-sale Debt Securities) - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Corporate and municipal bonds	$ 45,300	$ 58,900
Maturity dates of bonds, start date	2020-04
Maturity dates of bonds, end date	2024-11
Unrealized losses on securities	$ 400
Funds held for clients	141,984	179,502
Certificates of Deposits and Other Depository Assets [Member]
Schedule Of Available For Sale Securities [Line Items]
Funds held for clients	$ 2,000	$ 2,500