Railcar Leasing and Management Services Group (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues:
Total revenues	$ 156.0	$ 147.4	$ 128.2	$ 119.8	$ 119.2	$ 115.2	$ 115.2	$ 114.9	$ 551.4	$ 464.5	$ 370.2
Operating Profit:
Total operating profit	139.0	105.4	95.4	85.5	81.0	91.9	78.9	52.0	425.3	303.8	(30.9)
Interest and rent expense:
Interest Expense, Total									185.3	182.1	123.2
Leasing Group [Member]
Revenues:
Total revenues									552.0	464.5	370.2
Percent Change									18.80%	25.50%
Operating Profit:
Total operating profit									254.5	207.0	149.0
Operating profit margin:
Total operating profit margin									46.10%	44.60%	40.20%
Interest and rent expense:
Rent expense									48.6	48.6	46.7
Interest Expense, Total									160.8	138.6	80.1
Leasing Group [Member] | Leasing and management [Member]
Operating profit margin:
Total operating profit margin									45.70%	43.40%	39.00%
Leasing Group [Member] | Sales of cars from the lease fleet [Member]
Operating profit margin:
Total operating profit margin									0.00%	0.00%	0.00%
Leasing Group [Member] | Wholly Owned Subsidiaries [Member]
Revenues:
Total revenues									434.5	348.5	370.2
Percent Change									24.70%	(5.90%)
Operating Profit:
Total operating profit									181.3	138.5	149.0
Interest and rent expense:
Interest Expense, Total									101.3	91.7	80.1
Leasing Group [Member] | Wholly Owned Subsidiaries [Member] | Leasing and management [Member]
Revenues:
Total revenues									375.1	345.4	329.3
Percent Change									8.60%	4.90%
Operating Profit:
Total operating profit									156.3	131.7	128.5
Leasing Group [Member] | Wholly Owned Subsidiaries [Member] | Sales of cars from the lease fleet [Member]
Revenues:
Total revenues									59.4	3.1	40.9
Percent Change									0.00%	0.00%
Leasing Group [Member] | Wholly Owned Subsidiaries [Member] | Railcar Owned One Year or Less [Member]
Operating Profit:
Total operating profit									13.2	0.2	2.1
Leasing Group [Member] | Wholly Owned Subsidiaries [Member] | Railcar Owned Greater than One Year [Member]
Operating Profit:
Total operating profit									11.8	6.6	18.4
Leasing Group [Member] | TRIP Holdings [Member]
Revenues:
Total revenues									117.5	116.0
Percent Change									1.30%
Operating Profit:
Total operating profit									73.2	68.5
Interest and rent expense:
Interest expense external									53.1	46.9
Interest expense intercompany									6.4
Interest Expense, Total									59.5	46.9
Leasing Group [Member] | TRIP Holdings [Member] | Leasing and management [Member]
Revenues:
Total revenues									117.5	116.0
Percent Change									1.30%
Operating Profit:
Total operating profit									68.8	68.5
Leasing Group [Member] | TRIP Holdings [Member] | Sales of cars from the lease fleet [Member]
Revenues:
Total revenues									0	0
Percent Change									0.00%
Leasing Group [Member] | TRIP Holdings [Member] | Railcar Owned One Year or Less [Member]
Operating Profit:
Total operating profit									0
Leasing Group [Member] | TRIP Holdings [Member] | Railcar Owned Greater than One Year [Member]
Operating Profit:
Total operating profit									$ 4.4