Acquisitions and Divestitures - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended		10 Months Ended	12 Months Ended					3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2013 Fallbrook [Member]	Dec. 31, 2013 Fallbrook [Member]	Dec. 31, 2012 Fallbrook [Member]	Sep. 30, 2013 Fallbrook [Member]	Sep. 30, 2013 Fallbrook [Member] Off-Highway Segment [Member]	Sep. 30, 2013 Fallbrook [Member] Light Vehicle Segment [Member]	Jun. 30, 2014 Structural Products [Member]	Jun. 30, 2014 Structural Products [Member]	Dec. 31, 2011 Structural Products [Member]	Mar. 31, 2014 Structural Products [Member]
Business Acquisitions and Investments in Equity Affiliates [Line Items]
Business acquisition, cash paid			$ 20	$ 8	$ 12
Business acquisition, purchase price allocated to indefinite-lived intangible assets						20	12	8
Cash proceeds from divestiture of business	9									9	134
Proceeds in escrow												10
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax									$ 1