Business Segments - Sales to Customers Contributing Ten Percent or More of Consolidated Sales (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Ford [Member]
Revenue, Major Customer [Line Items]
Major customers	27.00%	26.00%	24.00%
General Motors [Member]
Revenue, Major Customer [Line Items]
Major customers	17.00%	16.00%	16.00%
Fiat Chrysler Automobiles [Member]
Revenue, Major Customer [Line Items]
Major customers	12.00%	12.00%	13.00%