Construction Contracts (Net Position of Uncompleted Construction Contracts) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Contractors [Abstract]
Costs incurred on uncompleted construction contracts	$ 695,564	$ 594,006
Estimated earnings	24,553	20,375
Billings	(725,174)	(616,060)
Net position	(5,057)	(1,679)
Construction contract costs and estimated earnings in excess of billings	249	1,358
Billings in excess of construction contract costs and estimated earnings	$ (5,306)	$ (3,037)

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
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(c)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 912
-SubTopic 310
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=68054760&loc=d3e55302-109406

Reference 3: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(c)(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(c)(4))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_CostsInExcessOfBillingsOnUncompletedContractsOrPrograms
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant