Segment Information - Sales by Product (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting Information [Line Items]
Total sales	$ 772,031	$ 818,594
Specialty Products & Electronics
Segment Reporting Information [Line Items]
Total sales	378,269	425,537
Brake Products
Segment Reporting Information [Line Items]
Total sales	158,033	136,690
Remanufacturing, Overhaul & Build
Segment Reporting Information [Line Items]
Total sales	151,906	167,397
Other Transit Products
Segment Reporting Information [Line Items]
Total sales	48,795	46,803
Other
Segment Reporting Information [Line Items]
Total sales	$ 35,028	$ 42,167