Segment Information - Sales by Product (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Total sales	$ 723,601	$ 847,028	$ 1,495,632	$ 1,665,622
Specialty Products & Electronics
Segment Reporting Information [Line Items]
Total sales	339,188	448,292	717,457	873,829
Remanufacturing, Overhaul & Build
Segment Reporting Information [Line Items]
Total sales	156,981	151,859	315,014	288,549
Brake Products
Segment Reporting Information [Line Items]
Total sales	141,979	159,034	293,885	326,431
Other Transit Products
Segment Reporting Information [Line Items]
Total sales	49,643	50,864	98,438	97,667
Other
Segment Reporting Information [Line Items]
Total sales	$ 35,810	$ 36,979	$ 70,838	$ 79,146