Guarantor Subsidiaries Financial Information - Condensed Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 1,056,177	$ 916,034
Cost of sales	(745,296)	(646,327)
Gross profit	310,881	269,707
Total operating expenses	(179,602)	(155,195)
Income from operations	131,279	114,512
Interest expense, net	(20,284)	(19,858)
Other income (expense), net	2,586	4,811
Equity earnings	0	0
Income from operations before income taxes	113,581	99,465
Income tax (expense) benefit	(26,124)	(27,461)
Net income	87,457	72,004
Less: Net loss attributable to noncontrolling interest	909	1,885
Net income attributable to Wabtec shareholders	88,366	73,889
Comprehensive income attributable to Wabtec shareholders	167,374	121,842
Elimination
Condensed Financial Statements, Captions [Line Items]
Net sales	(48,493)	(31,610)
Cost of sales	40,685	24,196
Gross profit	(7,808)	(7,414)
Total operating expenses	0	0
Income from operations	(7,808)	(7,414)
Interest expense, net	0	0
Other income (expense), net	0	0
Equity earnings	(135,418)	(80,227)
Income from operations before income taxes	(143,226)	(87,641)
Income tax (expense) benefit	0	0
Net income	(143,226)	(87,641)
Less: Net loss attributable to noncontrolling interest	0	0
Net income attributable to Wabtec shareholders	(143,226)	(87,641)
Comprehensive income attributable to Wabtec shareholders	(143,226)	(87,641)
Parent | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Net sales	161,301	144,544
Cost of sales	(118,658)	(98,950)
Gross profit	42,643	45,594
Total operating expenses	(35,627)	(24,463)
Income from operations	7,016	21,131
Interest expense, net	(20,394)	(14,966)
Other income (expense), net	8,729	13,266
Equity earnings	106,698	68,285
Income from operations before income taxes	102,049	87,716
Income tax (expense) benefit	(13,682)	(14,165)
Net income	88,367	73,551
Less: Net loss attributable to noncontrolling interest	0	0
Net income attributable to Wabtec shareholders	88,367	73,551
Comprehensive income attributable to Wabtec shareholders	88,649	74,407
Guarantors | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Net sales	301,706	258,712
Cost of sales	(179,090)	(167,607)
Gross profit	122,616	91,105
Total operating expenses	(37,327)	(29,871)
Income from operations	85,289	61,234
Interest expense, net	2,301	2,160
Other income (expense), net	(2,469)	(1,260)
Equity earnings	28,720	11,942
Income from operations before income taxes	113,841	74,076
Income tax (expense) benefit	1,194	(141)
Net income	115,035	73,935
Less: Net loss attributable to noncontrolling interest	215	0
Net income attributable to Wabtec shareholders	115,250	73,935
Comprehensive income attributable to Wabtec shareholders	115,250	73,935
Non-Guarantors | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Net sales	641,663	544,388
Cost of sales	(488,233)	(403,966)
Gross profit	153,430	140,422
Total operating expenses	(106,648)	(100,861)
Income from operations	46,782	39,561
Interest expense, net	(2,191)	(7,052)
Other income (expense), net	(3,674)	(7,195)
Equity earnings	0	0
Income from operations before income taxes	40,917	25,314
Income tax (expense) benefit	(13,636)	(13,155)
Net income	27,281	12,159
Less: Net loss attributable to noncontrolling interest	694	1,885
Net income attributable to Wabtec shareholders	27,975	14,044
Comprehensive income attributable to Wabtec shareholders	$ 106,701	$ 61,141