Organization and Basis of Presentation Revenue Recognition (Details)	3 Months Ended	6 Months Ended
Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue from UK homebuilders	$ 611,000	$ 611,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 69,500,000	$ 69,500,000
Remaining performance obligation through years		2020

No definition available.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
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Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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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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No definition available.

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Year in which remaining performance obligation is expected to be recognized, in CCYY format.

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