Acquisitions and Divestitures - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								3 Months Ended	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Fallbrook [Member]	Dec. 31, 2012 Fallbrook [Member]	Sep. 10, 2012 Fallbrook [Member]	Mar. 31, 2013 Fallbrook [Member] Off-Highway	Mar. 31, 2013 Fallbrook [Member] LVD	Mar. 31, 2013 Structural Products	Mar. 31, 2012 Axle Differential and Brake Systems [Member]	Dec. 31, 2012 Axle Differential and Brake Systems [Member]
Business Acquisitions and Investments in Equity Affiliates [Line Items]
Business acquisition, purchase price					$ 20
Business acquisition, cash paid			4	5	7
Business acquisition, cash payable			4
Business acquisition, purchase price allocated to non-amortizable intangible assets			20			12	8
Proceeds in escrow								12
Cash proceeds from divestiture of business										8
Asset impairment for sales of business based on our current estimate of the expected sales price		2							2
Sales of divested business										$ 32