Net loss per common share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net loss per common share
Net loss	$ (14)	$ (7)
Weighted average number of common shares outstanding - basic (in shares)	75.0	73.2
Weighted average number of common shares outstanding - diluted (in shares)	75.0	73.2
Basic net loss per common share
Basic net loss per common share (in dollars per share)	$ (0.19)	$ (0.10)
Diluted net loss per common share
Diluted net loss per common share (in dollars per share)	$ (0.19)	$ (0.10)