Accounting Policies and Recent Accounting Pronouncements (Details) (USD $)	3 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended				6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2012 20-ft. standard dry van container [Member] Current [Member]	Mar. 31, 2012 20-ft. standard dry van container [Member] Prior [Member]	Jun. 30, 2012 40-ft. standard dry van container [Member] Current [Member]	Mar. 31, 2012 40-ft. standard dry van container [Member] Prior [Member]	Jun. 30, 2012 40-ft. high cube dry van container [Member] Current [Member]	Mar. 31, 2012 40-ft. high cube dry van container [Member] Prior [Member]	Jun. 30, 2012 20-ft. refrigerated container [Member] Current [Member]	Mar. 31, 2012 20-ft. refrigerated container [Member] Prior [Member]	Jun. 30, 2012 40-ft. high cube refrigerated container [Member] Current [Member]	Mar. 31, 2012 40-ft. high cube refrigerated container [Member] Prior [Member]	Mar. 31, 2012 Other specialized containers [Member]	Jun. 30, 2012 Other specialized containers [Member] Maximum [Member]	Mar. 31, 2012 Other specialized containers [Member] Minimum [Member]	Jun. 30, 2012 Railcar Equipment [Member]
Property, Plant and Equipment [Line Items]
Residual Value			$ 1,050,000	$ 950,000	$ 1,300,000	$ 1,150,000	$ 1,650,000	$ 1,300,000	$ 2,750,000	$ 2,250,000	$ 3,500,000	$ 3,000,000		$ 3,500,000	$ 1,000,000
Depreciable life			13 years	12 years 6 months	13 years	12 years 6 months	13 years	12 years 6 months	12 years	12 years	12 years	12 years	12 years 6 months			40 years
Reduction in depreciation expense due to change in residual values and estimated useful lives	1,900,000	3,600,000
Increase in pre tax income due to change in residual values and estimated useful lives	1,900,000	3,600,000
Increase in net income	$ 1,700,000	$ 3,100,000
Increase in diluted earnings per share (in dollars per share)	$ 0.09	$ 0.16
Recent Accounting Pronouncements
Presentation of net income and comprehensive income, description		either one or two