Retirement Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Retirement Plans
Defined Contribution Plan, Cost Recognized	$ 312.4	$ 466.9	$ 382.8
Profit sharing component	$ 264.6	$ 421.6	$ 359.8
Percentage of employer's profit sharing contribution	8.00%	8.00%	8.00%
Employer's contribution to profit sharing plans for eligible employees	$ 211.6	$ 337.2	$ 287.8