Goodwill and Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Goodwill impairment charge	$ 379,863
Goodwill	205,143	[1]	$ 585,006
Accumulated Impairment	867,800		487,985
Amortization expense	6,226		3,543	$ 3,543
Finite-Lived intangible assets
2020	31,200
2021	31,100
2022	20,200
2023	2,500
2024	2,500
Trade Names
Indefinite-lived intangible assets
Indefinite-lived intangible assets, carrying value	50,400		50,400
Trade Names
Finite-Lived intangible assets
Finite-lived intangible assets, gross carrying value	51,100		51,100
Accumulated Amortization	$ 21,300		18,800
Weighted Average Amortization Period	20 years
Customer relationships
Finite-Lived intangible assets
Finite-lived intangible assets, gross carrying value	$ 23,200		23,200
Accumulated Amortization	$ 21,000		20,000
Weighted Average Amortization Period	12 years
Construction contract backlog
Finite-Lived intangible assets
Finite-lived intangible assets, gross carrying value	$ 149,300		73,700
Accumulated Amortization	76,400		$ 73,700
Increase in finite-lived assets, from acquisition	$ 75,600
Weighted Average Amortization Period	3 years

[1] As of December 31, 2019, accumulated impairment was $867.8 million.