Cash, Cash Equivalents, and Restricted Cash (Narrative) (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Restricted Cash And Cash Equivalents Items [Line Items]
Surety, payment and performance bonds	$ 42,000,000.0	$ 42,300,000
Collateral payment for performance bonds	0	0
Workers Compensation Policy [Member]
Restricted Cash And Cash Equivalents Items [Line Items]
Collateral	2,400,000	2,300,000
Payment and Performance Bonds [Member]
Restricted Cash And Cash Equivalents Items [Line Items]
Collateral	$ 5,700,000	$ 6,000,000.0