Net Income (loss) per share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator:
Net income (loss)	$ (75.7)	$ (32.7)	$ (135.8)	$ 41.6
Denominator:
Weighted-average number of shares-basic (in shares)	49.9	53.7	50.2	53.6
Dilutive securities-equity awards (in shares)	0.0	0.0	0.0	0.7
Weighted-average number of shares-diluted (in shares)	49.9	53.7	50.2	54.3
Net income per share - basic (in dollars per share)	$ (1.52)	$ (0.61)	$ (2.71)	$ 0.78
Net income per share - diluted (in dollars per share)	$ (1.52)	$ (0.61)	$ (2.71)	$ 0.77
Anti-dilutive stock awards (in shares)	3.3	1.4	2.6	0.6