Guarantor Subsidiaries Financial Information - Income Statement (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Condensed Financial Statements, Captions [Line Items]
Total net sales	$ 1,929.9	$ 1,593.6
Total cost of sales	(1,351.2)	(1,204.6)
Gross profit	578.7	389.0
Total operating expenses	(361.4)	(321.7)
Income from operations	217.3	67.3
Interest expense, net	(53.3)	(44.6)
Other expense, net	(14.8)	(8.2)
Equity earnings (loss)	0.0	0.0
Income from operations before income taxes	149.2	14.5
Income tax (expense) benefit	(38.0)	(18.5)
Net income (loss)	111.2	(4.0)
Less: Net loss (gain) attributable to noncontrolling interest	0.4	(0.5)
Net income (loss) attributable to Wabtec shareholders	111.6	(4.5)
Comprehensive income (loss) attributable to Wabtec shareholders	(66.4)	(56.9)
Elimination
Condensed Financial Statements, Captions [Line Items]
Total net sales	(506.5)	(55.5)
Total cost of sales	404.6	33.1
Gross profit	(101.9)	(22.4)
Total operating expenses	0.0	0.0
Income from operations	(101.9)	(22.4)
Interest expense, net	0.0	0.0
Other expense, net	0.0	0.0
Equity earnings (loss)	(334.8)	(171.3)
Income from operations before income taxes	(436.7)	(193.7)
Income tax (expense) benefit	0.0	0.0
Net income (loss)	(436.7)	(193.7)
Less: Net loss (gain) attributable to noncontrolling interest	0.0	0.0
Net income (loss) attributable to Wabtec shareholders	(436.7)	(193.7)
Comprehensive income (loss) attributable to Wabtec shareholders	(436.7)	(193.7)
Parent | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Total net sales	168.4	193.1
Total cost of sales	(128.6)	(157.7)
Gross profit	39.8	35.4
Total operating expenses	(53.4)	(97.5)
Income from operations	(13.6)	(62.1)
Interest expense, net	(51.1)	(41.6)
Other expense, net	(32.8)	20.3
Equity earnings (loss)	220.7	91.5
Income from operations before income taxes	123.2	8.1
Income tax (expense) benefit	(11.7)	(12.5)
Net income (loss)	111.5	(4.4)
Less: Net loss (gain) attributable to noncontrolling interest	0.0	0.0
Net income (loss) attributable to Wabtec shareholders	111.5	(4.4)
Comprehensive income (loss) attributable to Wabtec shareholders	111.5	(4.4)
Guarantors | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Total net sales	903.0	128.8
Total cost of sales	(748.1)	(82.0)
Gross profit	154.9	46.8
Total operating expenses	(63.8)	(15.3)
Income from operations	91.1	31.5
Interest expense, net	2.4	3.5
Other expense, net	49.8	(2.5)
Equity earnings (loss)	114.1	79.8
Income from operations before income taxes	257.4	112.3
Income tax (expense) benefit	22.1	0.0
Net income (loss)	279.5	112.3
Less: Net loss (gain) attributable to noncontrolling interest	0.0	0.0
Net income (loss) attributable to Wabtec shareholders	279.5	112.3
Comprehensive income (loss) attributable to Wabtec shareholders	279.5	112.3
Non-Guarantors | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Total net sales	1,365.0	1,327.2
Total cost of sales	(879.1)	(998.0)
Gross profit	485.9	329.2
Total operating expenses	(244.2)	(208.9)
Income from operations	241.7	120.3
Interest expense, net	(4.6)	(6.5)
Other expense, net	(31.8)	(26.0)
Equity earnings (loss)	0.0	0.0
Income from operations before income taxes	205.3	87.8
Income tax (expense) benefit	(48.4)	(6.0)
Net income (loss)	156.9	81.8
Less: Net loss (gain) attributable to noncontrolling interest	0.4	(0.5)
Net income (loss) attributable to Wabtec shareholders	157.3	81.3
Comprehensive income (loss) attributable to Wabtec shareholders	$ (20.7)	$ 28.9