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Revenue Recognition - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2019 | Jun. 30, 2019 | Dec. 31, 2018
Disaggregation Of Revenue [Line Items] |  |  |
Period for credit risk identified |  | 30 days |
Sales revenues totaling | $ 0.6 | $ 4.0 |
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 | 33.1 | $ 33.1 | $ 15.7
Accounts Receivable [Member] |  |  |
Disaggregation Of Revenue [Line Items] |  |  |
Unbilled contract assets | $ 0.8 | $ 0.8 | $ 1.4

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- Definition Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045 + Details
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