Debt - Summary (Details) - USD ($) $ in Millions	Dec. 31, 2023	Jan. 15, 2023	Dec. 31, 2022
Debt
Total	$ 1,151.4		$ 1,659.6
Less: unamortized discount and debt issuance costs	(9.2)		(12.0)
Less: amounts due within one year and short-term borrowings	(0.3)		(508.2)
Total long-term debt	1,141.9		1,139.4
Unsecured revolving credit facility maturing September 3, 2025
Debt
Total	0.0		0.0
Senior unsecured notes, interest payable semi-annually at 4.50%, effective rate of 4.63%, redeemed on January 15, 2023
Debt
Total	$ 0.0		$ 500.0
Semi-annual rate (as a percent)	4.50%	4.50%	4.50%
Effective rate (as a percent)	4.63%		4.63%
Senior unsecured notes, interest payable semi-annually at 1.30%, effective rate of 1.53%, maturing August 15, 2025
Debt
Total	$ 400.0		$ 400.0
Semi-annual rate (as a percent)	1.30%		1.30%
Effective rate (as a percent)	1.53%		1.53%
Senior unsecured notes, interest payable semi-annually at 2.15%, effective rate of 2.27%, maturing August 15, 2030
Debt
Total	$ 500.0		$ 500.0
Semi-annual rate (as a percent)	2.15%		2.15%
Effective rate (as a percent)	2.27%		2.27%
Senior unsecured notes, interest payable semi-annually at 6.85%, effective rate of 6.91%, maturing November 15, 2036
Debt
Total	$ 250.0		$ 250.0
Semi-annual rate (as a percent)	6.85%		6.85%
Effective rate (as a percent)	6.91%		6.91%
Other notes and revolving credit facilities
Debt
Total	$ 1.4		$ 9.6