EARNINGS PER SHARE - Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator
Net income attributable to Wabtec shareholders	$ 149.0	$ 112.0
Denominator
Weighted average shares outstanding- basic (in shares)	184.5	188.5
Assumed conversion of dilutive stock-based compensation plans (in shares)	0.5	0.4
Weighted average shares outstanding- diluted (in shares)	185.0	188.9
Net income attributable to Wabtec shareholders per common share
Basic (in dollars per share)	$ 0.80	$ 0.59
Diluted (in dollars per share)	$ 0.80	$ 0.59