Contract assets and deferred revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Contract assets - current	$ 28.9	$ 42.0
Contract assets - long-term	11.0	17.4
Deferred revenue - current	(200.7)	(253.2)
Deferred revenue - long-term	(122.3)	(150.7)
Revenue recognized that was included in deferred revenue at the beginning of the period	$ 235.4	$ 245.8