Commitments And Contingencies (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Letters of credit outstanding, amount	$ 312,700	$ 303,400
Surety Bonds Outstanding	2,400,000	2,200,000
Self-insurance liabilities	$ 563,103	$ 635,857	$ 627,067	$ 641,779
Incurred but not reported percentage of liability reserves	77.00%	74.00%
Adjustment to self insurance reserves	$ (130,841)	$ (64,965)	(81,131)
Right-of-use assets	77,400	73,485
Operating Lease, Liability	91,554	90,083
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	20,600	14,500
Operating Lease, Payments	23,400	21,900	20,800
Variable Lease, Cost	11,800	9,900	7,700
Short-term Lease, Cost	17,300	21,200	14,200
Lease, Cost	56,400	54,800	$ 43,300
Unsecured Letter Of Credit Facility [Member]
Loss Contingencies [Line Items]
Letters of credit outstanding, amount	$ 312,700	$ 303,400