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Revenue from Contracts with Customers - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) contract	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Minimum
Disaggregation of Revenue [Line Items]
Revenue recognition, contract term	12 months
Warranty, term	1 year
Maximum
Disaggregation of Revenue [Line Items]
Revenue recognition, contract term	36 months
Warranty, term	2 years
Transferred over Time | Product Concentration Risk | Revenue from Contract with Customer
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	85.00%	89.00%	100.00%
Transferred at Point in Time | Product Concentration Risk | Revenue from Contract with Customer
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	15.00%	11.00%
Heavy Civil Construction
Disaggregation of Revenue [Line Items]
Number of contracts (more than) | contract	150
Operating income (Loss)
Disaggregation of Revenue [Line Items]
Estimated construction gain (loss) before tax	$ 7.1	$ 0.9	$ (6.3)
Costs and Estimated Earnings in Excess of Billings
Disaggregation of Revenue [Line Items]
Contracts receivable unpaid project contract price	$ 9.3	$ 10.0

X

- Definition

Amount of unpaid project contract price that the Company is entitled to.

+ References

No definition available.

+ Details

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X

- Definition

Represents net estimated gross profit (loss) before tax.

+ References

No definition available.

+ Details

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X

- Definition

Revenue From Contract With Customer, Number Of Contracts

+ References

No definition available.

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X

- Definition

Represents the length of time the Company's contracts generally take to complete.

+ References

No definition available.

+ Details

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- Definition

Warranty, term

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No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 825
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- Definition

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.

+ References

No definition available.

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