GUARANTOR SUBSIDIARIES FINANCIAL INFORMATION - Condensed Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 759,982	$ 675,574	$ 723,601	$ 772,031	$ 832,849	$ 809,527	$ 847,028	$ 818,594	$ 2,931,188	$ 3,307,998	$ 3,044,454
Cost of sales									(2,006,949)	(2,260,182)	(2,108,472)
Gross profit	219,189	212,481	237,389	255,180	267,628	257,069	267,764	255,355	924,239	1,047,816	935,982
Total operating expenses									(465,878)	(440,249)	(408,873)
Income from operations	62,800	120,096	133,284	142,181	151,209	152,078	155,860	148,420	458,361	607,567	527,109
Interest expense, net									(42,561)	(16,888)	(17,574)
Other (expense) income, net									(2,963)	(5,311)	(1,680)
Equity earnings (loss)									0	0	0
Income from operations before income taxes									412,837	585,368	507,855
Income tax expense									(99,433)	(186,740)	(156,175)
Net income									313,404	398,628	351,680
Less: Net income attributable to noncontrolling interest									(8,517)	0	0
Net income attributable to Wabtec shareholders	$ 37,811	$ 82,428	$ 90,485	$ 94,163	$ 101,779	$ 99,181	$ 101,504	$ 96,164	304,887	398,628	351,680
Comprehensive income attributable to Wabtec shareholders									202,001	281,395	227,050
Elimination
Condensed Financial Statements, Captions [Line Items]
Net sales									(145,559)	(172,776)	(195,893)
Cost of sales									103,421	90,989	121,153
Gross profit									(42,138)	(81,787)	(74,740)
Total operating expenses									0	0	0
Income from operations									(42,138)	(81,787)	(74,740)
Interest expense, net									0	0	0
Other (expense) income, net									0	0	0
Equity earnings (loss)									(453,884)	(619,189)	(489,438)
Income from operations before income taxes									(496,022)	(700,976)	(564,178)
Income tax expense									0	0	0
Net income									(496,022)	(700,976)	(564,178)
Less: Net income attributable to noncontrolling interest									0	0	0
Net income attributable to Wabtec shareholders									(496,022)	(700,976)	(564,178)
Comprehensive income attributable to Wabtec shareholders									(496,022)	(700,976)	(564,178)
Parent
Condensed Financial Statements, Captions [Line Items]
Net sales									641,809	743,262	722,317
Cost of sales									(473,700)	(531,269)	(516,607)
Gross profit									168,109	211,993	205,710
Total operating expenses									(141,940)	(142,953)	(140,002)
Income from operations									26,169	69,040	65,708
Interest expense, net									(34,975)	(23,129)	(23,551)
Other (expense) income, net									20,509	23,193	18,295
Equity earnings (loss)									322,650	506,903	399,507
Income from operations before income taxes									334,353	576,007	459,959
Income tax expense									(29,466)	(177,379)	(108,279)
Net income									304,887	398,628	351,680
Less: Net income attributable to noncontrolling interest									0	0	0
Net income attributable to Wabtec shareholders									304,887	398,628	351,680
Comprehensive income attributable to Wabtec shareholders									305,180	409,734	345,581
Guarantors
Condensed Financial Statements, Captions [Line Items]
Net sales									1,112,001	1,436,935	1,239,154
Cost of sales									(708,062)	(843,104)	(730,946)
Gross profit									403,939	593,831	508,208
Total operating expenses									(122,617)	(131,251)	(116,569)
Income from operations									281,322	462,580	391,639
Interest expense, net									7,012	5,914	5,793
Other (expense) income, net									(2,284)	(9,140)	(3,334)
Equity earnings (loss)									131,234	112,286	89,931
Income from operations before income taxes									417,284	571,640	484,029
Income tax expense									(57,667)	8,989	(15,222)
Net income									359,617	580,629	468,807
Less: Net income attributable to noncontrolling interest									0	0	0
Net income attributable to Wabtec shareholders									359,617	580,629	468,807
Comprehensive income attributable to Wabtec shareholders									359,617	580,629	468,807
Non-Guarantors
Condensed Financial Statements, Captions [Line Items]
Net sales									1,322,937	1,300,577	1,278,876
Cost of sales									(928,608)	(976,798)	(982,072)
Gross profit									394,329	323,779	296,804
Total operating expenses									(201,321)	(166,045)	(152,302)
Income from operations									193,008	157,734	144,502
Interest expense, net									(14,598)	327	184
Other (expense) income, net									(21,188)	(19,364)	(16,641)
Equity earnings (loss)									0	0	0
Income from operations before income taxes									157,222	138,697	128,045
Income tax expense									(12,300)	(18,350)	(32,674)
Net income									144,922	120,347	95,371
Less: Net income attributable to noncontrolling interest									(8,517)	0	0
Net income attributable to Wabtec shareholders									136,405	120,347	95,371
Comprehensive income attributable to Wabtec shareholders									$ 33,226	$ (7,992)	$ (23,160)