Summary of Significant Accounting Policies (General Contractor Revenue) (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Billings in Excess of Cost	$ 161,000	$ 276,000
Costs in Excess of Billings	$ 29,100,000	$ 8,300,000

Amount of receivable reflecting the cost incurred on uncompleted contracts in excess of related billings.

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
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-Subparagraph (SX 210.5-02(3)(c)(2))
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Reference 3: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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Reference 4: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
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Period Type:	instant