Segment Information (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 ft	Jun. 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
Segment Reporting Information [Line Items]
Total revenue	39,725,000	28,759,000	79,132,000	56,501,000
Operating expenses	15,363,000	11,839,000	31,878,000	21,065,000
Operating income	24,362,000	16,920,000	47,254,000	35,436,000
Net interest expense	6,318,000	3,528,000	12,249,000	6,499,000
Net income before income taxes and non-controlling interest	18,044,000	13,392,000	35,005,000	28,937,000
Total assets	1,171,957,000	820,559,000	1,171,957,000	820,559,000	953,368,000
Equipment Leasing [Member]
Segment Reporting Information [Line Items]
Total revenue	36,719,000	25,231,000	70,669,000	48,048,000
Operating expenses	13,394,000	9,487,000	27,714,000	16,722,000
Operating income	23,325,000	15,744,000	42,955,000	31,326,000
Net interest expense	6,320,000	3,529,000	12,256,000	6,503,000
Net income before income taxes and non-controlling interest	17,005,000	12,215,000	30,699,000	24,823,000
Total assets	1,149,676,000	799,188,000	1,149,676,000	799,188,000
Container Management [Member]
Segment Reporting Information [Line Items]
Total revenue	3,006,000	3,528,000	8,463,000	8,453,000
Operating expenses	1,969,000	2,352,000	4,164,000	4,343,000
Operating income	1,037,000	1,176,000	4,299,000	4,110,000
Net interest expense	0	0	0	0
Net income before income taxes and non-controlling interest	1,037,000	1,176,000	4,299,000	4,110,000
Total assets	22,281,000	21,371,000	22,281,000	21,371,000
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	(2,000)	(1,000)	(7,000)	(4,000)
Net income before income taxes and non-controlling interest	2,000	1,000	7,000	4,000
Total assets	$ 0	$ 0	$ 0	$ 0