Accounting Policies - Reclassifications Out of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Cost of sales	$ 646,327	$ 516,851
Income from Operations	99,465	137,464
Income tax expense	(27,461)	(43,301)
Interest expense, net	(17,712)	(4,871)
Net income attributable to Wabtec shareholders	73,889	94,163
Reclassification out of Accumulated Other Comprehensive Income | Pension and post retirement benefit plans
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Income from Operations	818	735
Income tax expense	(226)	(231)
Net income attributable to Wabtec shareholders	592	504
Reclassification out of Accumulated Other Comprehensive Income | Amortization of initial net obligation and prior service cost
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Cost of sales	(422)	(385)
Reclassification out of Accumulated Other Comprehensive Income | Amortization of net loss
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Cost of sales	1,240	1,120
Reclassification out of Accumulated Other Comprehensive Income | Derivative contracts
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income On Derivatives [Line Items]
Income tax expense	(163)	(149)
Interest expense, net	589	474
Net income attributable to Wabtec shareholders	$ 426	$ 325