Equity Appreciation Rights - Stock-based compensation cost by award type (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total Equity appreciation rights expense	$ 11.3	$ 5.3	$ 38.0	$ 32.6
EAR Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total Equity appreciation rights expense	0.0	5.3	0.0	32.6
Amended EAR Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Total Equity appreciation rights expense	$ 11.3	$ 0.0	$ 38.0	$ 0.0