Revenue Concentration (Details) (Equipment Leasing [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Ten Largest Container Lessees [Member]
Concentration Risk [Line Items]
Number of major customers	10
Single Largest Container Lessee [Member]
Concentration Risk [Line Items]
Concentration of risk (in hundredths)	11.40%	11.20%	11.70%
Concentration of risk, amount	$ 25.9	$ 23.8	$ 20.3
Revenue [Member]
Concentration Risk [Line Items]
Concentration of risk (in hundredths)	55.40%	56.60%	54.00%