Common stock and additional paid-in capital - Schedule of Stockholders' Equity (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, common shares, outstanding (in shares)	178.2
Beginning balance, equity	$ 376.4	$ 501.6
Stock-based compensation - RSUs	2.7	2.7
Stock-based compensation - options	$ 0.6	0.7
Ending balance, common shares, outstanding (in shares)	179.1
Ending balance, equity	$ 243.0	$ 468.5
Number of common shares
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, common shares, outstanding (in shares)	178.2	176.1
Settlement of RSUs (in shares)	0.9	0.4
Ending balance, common shares, outstanding (in shares)	179.1	176.5
Common stock and additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, equity	$ 648.3	$ 635.3
Stock-based compensation - RSUs	2.7	2.7
Stock-based compensation - options	0.6	0.7
Ending balance, equity	$ 651.6	$ 638.7