Revenue Recognition - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Period for credit risk identified		30 days
Sales revenues totaling	$ 5.8	$ 9.8
Period for warranties for rental equipment		90 days
Period for warranties for equipment manufactured		1 year
Deferred Income [Member]
Disaggregation Of Revenue [Line Items]
Customer contract liability	18.6	$ 18.6	$ 15.7
Accounts Receivable [Member]
Disaggregation Of Revenue [Line Items]
Unbilled contract assets	$ 3.5	$ 3.5	$ 1.4