Implemented Accounting Pronouncements - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Bad debt expense	$ 552,000	$ 156,000
Allowance for doubtful accounts	2,200,000		$ 1,883,000
Net investment in sales-type leases	2,500,000		$ 2,900,000
Credit loss expense	$ 0
Minimum [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Sales-type leases terms	12 months
Maximum [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Sales-type leases terms	36 months