Commitments and Contingencies (Warranty activity) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Letters of Credit Outstanding, Amount	$ 9,000		$ 9,000
Movement in Standard Product Warranty Accrual [Roll Forward]
Standard Product Warranty Accrual, Increase (Decrease) for Preexisting Warranties	(87)	$ (144)
Accrued Expenses
Movement in Standard Product Warranty Accrual [Roll Forward]
Warranty accrual, beginning of period	3,840	2,980
Warranties issued	840	653
Settlements	(420)	(862)
Warranty accrual, end of period	4,173	$ 2,627
Performance Bonds
Product Warranty Liability [Line Items]
Amount of performance bonds outstanding	$ 6,200		$ 5,400

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The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount as of the balance sheet date of the aggregate standard product warranty liability. Does not include the balance for the extended product warranty liability.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Amount of decrease in the standard product warranty accrual from payments made in cash or in kind to satisfy claims under the terms of the standard product warranty. Excludes extended product warranties.

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Amount of increase (decrease) in the standard product warranty accrual from changes in estimates attributable to preexisting product warranties. Excludes extended product warranties.

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Amount of increase in the standard product warranty accrual from warranties issued. Excludes extended product warranties.

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