Commitments and Contingencies (Narrative) (Details) - USD ($)				3 Months Ended
	Jun. 15, 2021	Apr. 23, 2021	Jan. 14, 2015	Mar. 31, 2022	Apr. 22, 2022	Apr. 18, 2022
Commitments And Contingencies [Line Items]
Outstanding performance bonds				$ 1,178,796,000
Revenue value remaining from outstanding performance bonds				473,471,000
Proceeds from Legal Settlements			$ 5,309,000
Fine for violation	$ 1,000,000
Potential liability for criminal matters					$ 2,000,000
Indemnification Commitment [Member]
Commitments And Contingencies [Line Items]
Aggregate demolition surety performance bond		$ 21,934,000
Minimum [Member]
Commitments And Contingencies [Line Items]
Bids bond range				$ 1,000,000
Warranty periods				1 year
Restitution owe on liability for criminal matters previously deposited						$ 0
Maximum [Member]
Commitments And Contingencies [Line Items]
Bids bond range				$ 10,000,000
Warranty periods				3 years
Restitution owe on liability for criminal matters previously deposited						$ 2,000,000