Allowance for Doubtful Accounts - Summary of Allowance for Doubtful Accounts (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Schedule of Allowance for Doubtful Accounts Receivable [Line Items]
Available-for-sale Securities	$ 151,750,000
Debt Securities, Available-for-sale	156,757,000	$ 139,718,000
Allowance for Doubtful Accounts Receivable	5,209,000	$ 5,140,000
Debt Securities, Available-for-sale, Unrealized Gain (Loss)	18,000
Allowance for Doubtful Accounts Receivable [Roll Forward]
Provision charged to income	639,000
Write-offs	(514,000)
Currency	(56,000)
Cash and Cash Equivalents [Member]
Schedule of Allowance for Doubtful Accounts Receivable [Line Items]
Debt Securities, Available-for-sale	151,750,000
Investments [Domain]
Schedule of Allowance for Doubtful Accounts Receivable [Line Items]
Available-for-sale Securities	$ 0