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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

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