CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income attributable to Wabtec shareholders	$ 91.1	$ 87.7	$ 191.0	$ 260.6
Foreign currency translation loss	(181.1)	(44.3)	(208.9)	(159.0)
Unrealized gain (loss) on derivative contracts	0.2	0.0	(4.0)	(5.5)
Unrealized gain (loss) on pension benefit plans and post-retirement benefit plans	2.2	(6.9)	(0.1)	3.3
Other comprehensive income (loss) before tax	(178.7)	(51.2)	(213.0)	(161.2)
Income tax (benefit) expense related to components of other comprehensive income	(0.7)	1.7	1.0	0.5
Other comprehensive income (loss), net of tax	(179.4)	(49.5)	(212.0)	(160.7)
Comprehensive income (loss) attributable to Wabtec shareholders	$ (88.3)	$ 38.2	$ (21.0)	$ 99.9