Debt Narrative - Senior Unsecured Notes - Railcar (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended				9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Railcar Segment [Member]	Sep. 30, 2011 Railcar Segment [Member]	Sep. 30, 2012 Railcar Segment [Member]	Sep. 30, 2011 Railcar Segment [Member]	Sep. 30, 2012 Railcar Segment [Member] Senior unsecured notes [Member]	Feb. 28, 2007 Railcar Segment [Member] Senior unsecured notes [Member]	Sep. 30, 2012 Debt repurchase date range, from March 1, 2012 to February 28, 2013 [Member] Railcar Segment [Member] Senior unsecured notes [Member]	Sep. 30, 2012 Debt repurchase date range, on or after March 1, 2013 [Member] Railcar Segment [Member] Senior unsecured notes [Member]	Sep. 30, 2012 Loss on Debt Extinguishment [Member]	Sep. 30, 2011 Loss on Debt Extinguishment [Member]	Sep. 30, 2012 Loss on Debt Extinguishment [Member]	Sep. 30, 2011 Loss on Debt Extinguishment [Member]	Sep. 30, 2012 Loss on Debt Extinguishment [Member] Railcar Segment [Member]
Debt Instrument [Line Items]
Aggregate principal amount issued, long-term debt										$ 275
Repayments of Long-term Debt					100
Other (loss) income, net	$ (171)	$ (24)	$ (162)	$ (56)	$ (2)	$ (2)	$ (2)	$ (7)					$ (2)	$ 0	$ (4)	$ 0	$ (2)
Interest rate, long-term debt									7.50%
Fixed coverage ratio									2.0
Redemtion percentage of principal amount											101.875%	100.00%