Acquisitions and Divestitures - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended			12 Months Ended		10 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Structural Products [Member]	Dec. 31, 2011 Structural Products [Member]	Mar. 31, 2014 Structural Products [Member]	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]
Business Acquisition [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	1	9	134
Proceeds in escrow					10
Charge to discontinued operations			$ 1