Investments (Change in Accounting Principle) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Schedule of Equity Method Investments [Line Items]
INVESTMENTS	$ 29,379,249		$ 29,379,249			$ 25,292,634
Investments in affiliates	4,008,136		4,008,136			3,428,633
Retained earnings	105,536,192	97,076,067	105,536,192	97,076,067	100,247,941	98,518,546	96,413,662	97,758,013
Total stockholders' equity	123,438,435		123,438,435			114,432,381
Dividend income	422,650	87,786	622,496	1,573,786
Equity in affiliate earnings (losses), net of tax	52,489	(3,022)	58,327	(15,275)
Net income	6,247,378	1,969,365	8,916,876	1,891,022
Net income per share (in dollars per share)	$ 1.57	$ 0.50	$ 2.25	$ 0.48
General Finance Incorporated (GFI) [Member]
Schedule of Equity Method Investments [Line Items]
Investments in affiliates	4,008,136		4,008,136			3,428,633
Equity in affiliate earnings (losses), net of tax		(3,022)		(15,275)
Net income		1,969,365		1,891,022
Net income per share (in dollars per share)		$ 0.50		$ 0.48
As Previously Reported [Member] | General Finance Incorporated (GFI) [Member]
Schedule of Equity Method Investments [Line Items]
Equity in affiliate earnings (losses), net of tax		0		0
Net income		$ 1,972,388		$ 1,911,920
Net income per share (in dollars per share)		$ 0.49		$ 0.48