Segment Information (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Segment Information [Abstract]
Number of operating industry segments			1
Number of reportable segments			2
Inter-segment revenues			$ 0
Size of containers (in foots)			20
Net book value	50,200,000		50,200,000
Segment Reporting Information [Line Items]
Total revenue	44,939,000	32,962,000	124,071,000	89,463,000
Operating expenses	18,893,000	11,274,000	50,771,000	32,339,000
Operating income	26,046,000	21,688,000	73,300,000	57,124,000
Net interest expense	7,178,000	4,298,000	19,427,000	10,797,000
Net income before income taxes and non-controlling interest	18,868,000	17,390,000	53,873,000	46,327,000
Total assets	1,285,858,000	900,649,000	1,285,858,000	900,649,000	953,368,000
Equipment Leasing [Member]
Segment Reporting Information [Line Items]
Total revenue	42,447,000	29,215,000	113,116,000	77,263,000
Operating expenses	17,493,000	8,999,000	45,207,000	25,722,000
Operating income	24,954,000	20,216,000	67,909,000	51,541,000
Net interest expense	7,179,000	4,300,000	19,435,000	10,803,000
Net income before income taxes and non-controlling interest	17,775,000	15,916,000	48,474,000	40,738,000
Total assets	1,264,242,000	879,443,000	1,264,242,000	879,443,000
Container Management [Member]
Segment Reporting Information [Line Items]
Total revenue	2,492,000	3,747,000	10,955,000	12,200,000
Operating expenses	1,400,000	2,275,000	5,564,000	6,617,000
Operating income	1,092,000	1,472,000	5,391,000	5,583,000
Net interest expense	0	0	0	0
Net income before income taxes and non-controlling interest	1,092,000	1,472,000	5,391,000	5,583,000
Total assets	21,616,000	21,206,000	21,616,000	21,206,000
Unallocated [Member]
Segment Reporting Information [Line Items]
Total revenue	0	0	0	0
Operating expenses	0	0	0	0
Operating income	0	0	0	0
Net interest expense	(1,000)	(2,000)	(8,000)	(6,000)
Net income before income taxes and non-controlling interest	1,000	2,000	8,000	6,000
Total assets	$ 0	$ 0	$ 0	$ 0