Consolidation of Variable Interest Entities as a Non-Controlling Interest (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2010	Dec. 31, 2011
Variable Interest Entity [Line Items]
Number of specific Japanese funds			2
Net proceeds from sale of container portfolios		$ 4,300,000	$ 10,320,000	$ 12,642,000
Gain on sale of container portfolios	0	253,000	1,256,000	1,663,000
Cash	23,151,000	11,064,000	23,151,000	11,064,000	14,393,000	14,078,000
Fair value of net investment in direct finance leases	62,567,000		62,567,000			37,749,000
Non-controlling interest	19,278,000		19,278,000			18,700,000
Gain or loss recognized upon the initial consolidation					0
Net income attributable to non-controlling interest	513,000	211,000	578,000	410,000
Sale Leaseback Transaction [Line Items]
Net book value of financing arrangement	26,200,000		26,200,000
Collateralized financing obligation	26,800,000		26,800,000
Sale Leaseback Portfolio 1 [Member]
Sale Leaseback Transaction [Line Items]
Container portfolio transferred under collateralized financing obligation						10,000,000
Sale Leaseback Portfolio 2 [Member]
Sale Leaseback Transaction [Line Items]
Container portfolio transferred under collateralized financing obligation	17,200,000		17,200,000
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Net proceeds from sale of container portfolios		4,300,000	10,300,000	12,600,000
Gain on sale of container portfolios		300,000	1,300,000	1,700,000
Containers transferred to specific Japanese funds			13,600,000		16,000,000
Cash	3,300,000		3,300,000
Fair value of net investment in direct finance leases	1,600,000		1,600,000
Non-controlling interest	19,300,000		19,300,000
Net income attributable to non-controlling interest	$ 500,000	$ 200,000	$ 600,000	$ 400,000