Implemented Accounting Pronouncements - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Period for credit risk identified	30 days
Sales revenues totaling	$ 5.8
Unbilled contract assets	$ 32.3	$ 30.1
Period for warranties for rental equipment	90 days
Period for warranties for equipment manufactured	1 year
Deferred Income [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Customer contract liability	$ 15.7	6.8
Accounts Receivable [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Unbilled contract assets	$ 1.4	$ 2.0