Guarantor Subsidiaries Financial Information - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Condensed Financial Statements, Captions [Line Items]
Total net sales	$ 2,236,284		$ 1,111,680		$ 3,829,901	$ 2,167,857
Total cost of sales	(1,621,608)		(787,713)		(2,826,208)	(1,533,009)
Gross profit	614,676		323,967		1,003,693	634,848
Total operating expenses	(414,039)		(200,444)		(735,749)	(380,046)
Income from operations	200,637		123,523		267,944	254,802
Interest expense, net	(58,560)		(31,920)		(103,129)	(52,204)
Other income (expense), net	2,177		2,171		(6,051)	4,757
Equity earnings (loss)	0		0		0	0
Income from operations before income taxes	144,254		93,774		158,764	207,355
Income tax benefit (expense)	(41,400)		(10,503)		(59,923)	(36,627)
Net income	102,854	$ (4,013)	83,271	$ 87,457	98,841	170,728
Less: Net loss attributable to noncontrolling interest	1,381		1,145		922	2,054
Net income attributable to Wabtec shareholders	104,235		84,416		99,763	172,782
Comprehensive income attributable to Wabtec shareholders	124,055		(105,801)		67,166	61,573
Elimination
Condensed Financial Statements, Captions [Line Items]
Total net sales	(486,942)		(68,087)		(542,443)	(118,547)
Total cost of sales	380,167		38,755		413,251	70,834
Gross profit	(106,775)		(29,332)		(129,192)	(47,713)
Total operating expenses	0		0		0	0
Income from operations	(106,775)		(29,332)		(129,192)	(47,713)
Interest expense, net	0		0		0	0
Other income (expense), net	0		0		0	0
Equity earnings (loss)	(269,739)		(247,515)		(440,980)	(446,319)
Income from operations before income taxes	(376,514)		(276,847)		(570,172)	(494,032)
Income tax benefit (expense)	0		0		0	0
Net income	(376,514)		(276,847)		(570,172)	(494,032)
Less: Net loss attributable to noncontrolling interest	0		0		0	0
Net income attributable to Wabtec shareholders	(376,514)		(276,847)		(570,172)	(494,032)
Comprehensive income attributable to Wabtec shareholders	(376,514)		(276,847)		(570,172)	(494,032)
Parent | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Total net sales	185,695		168,426		378,761	329,727
Total cost of sales	(144,237)		(122,919)		(301,887)	(241,577)
Gross profit	41,458		45,507		76,874	88,150
Total operating expenses	(67,447)		(49,780)		(164,987)	(85,407)
Income from operations	(25,989)		(4,273)		(88,113)	2,743
Interest expense, net	(59,365)		(31,734)		(101,011)	(52,128)
Other income (expense), net	1,237		483		21,570	9,212
Equity earnings (loss)	185,813		128,744		277,295	235,442
Income from operations before income taxes	101,696		93,220		109,741	195,269
Income tax benefit (expense)	2,538		(7,213)		(9,979)	(20,895)
Net income	104,234		86,007		99,762	174,374
Less: Net loss attributable to noncontrolling interest	0		0		0	0
Net income attributable to Wabtec shareholders	104,234		86,007		99,762	174,374
Comprehensive income attributable to Wabtec shareholders	104,234		86,231		99,762	174,881
Guarantors | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Total net sales	1,104,741		137,966		1,233,544	256,083
Total cost of sales	(820,294)		(88,688)		(902,309)	(161,678)
Gross profit	284,447		49,278		331,235	94,405
Total operating expenses	(81,933)		(12,267)		(97,254)	(25,941)
Income from operations	202,514		37,011		233,981	68,464
Interest expense, net	3,116		3,137		6,594	6,079
Other income (expense), net	(4,217)		0		(6,702)	(679)
Equity earnings (loss)	83,926		118,771		163,685	210,877
Income from operations before income taxes	285,339		158,919		397,558	284,741
Income tax benefit (expense)	(42,556)		0		(42,556)	0
Net income	242,783		158,919		355,002	284,741
Less: Net loss attributable to noncontrolling interest	0		0		0	0
Net income attributable to Wabtec shareholders	242,783		158,919		355,002	284,741
Comprehensive income attributable to Wabtec shareholders	242,783		158,919		355,002	284,741
Non-Guarantors | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Total net sales	1,432,790		873,375		2,760,039	1,700,594
Total cost of sales	(1,037,244)		(614,861)		(2,035,263)	(1,200,588)
Gross profit	395,546		258,514		724,776	500,006
Total operating expenses	(264,659)		(138,397)		(473,508)	(268,698)
Income from operations	130,887		120,117		251,268	231,308
Interest expense, net	(2,311)		(3,323)		(8,712)	(6,155)
Other income (expense), net	5,157		1,688		(20,919)	(3,776)
Equity earnings (loss)	0		0		0	0
Income from operations before income taxes	133,733		118,482		221,637	221,377
Income tax benefit (expense)	(1,382)		(3,290)		(7,388)	(15,732)
Net income	132,351		115,192		214,249	205,645
Less: Net loss attributable to noncontrolling interest	1,381		1,145		922	2,054
Net income attributable to Wabtec shareholders	133,732		116,337		215,171	207,699
Comprehensive income attributable to Wabtec shareholders	$ 153,552		$ (74,104)		$ 182,574	$ 95,983