Fair Value Measurements - Assets and Liabilities Carried at Fair Value Measured on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Assets
Total assets at fair value	$ 1,473,950	$ 42,433,710
Level 1
Assets
Total assets at fair value	1,473,950	7,809,137
Level 3
Assets
Total assets at fair value		34,624,573
Investments in securities
Assets
Total assets at fair value	1,473,950
Investments in securities | Level 1
Assets
Total assets at fair value	$ 1,473,950
Self storage facilities | Wholly Owned Subsidiaries
Assets
Total assets at fair value		34,600,000
Self storage facilities | Level 3 | Wholly Owned Subsidiaries
Assets
Total assets at fair value		34,600,000
Other | Wholly Owned Subsidiaries
Assets
Total assets at fair value		24,573
Other | Level 3 | Wholly Owned Subsidiaries
Assets
Total assets at fair value		24,573
Common Stocks
Assets
Total assets at fair value		3,106,050
Common Stocks | Level 1
Assets
Total assets at fair value		3,106,050
Preferred Stocks
Assets
Total assets at fair value		1,176,750
Preferred Stocks | Level 1
Assets
Total assets at fair value		1,176,750
Short-term Investments
Assets
Total assets at fair value		3,526,337
Short-term Investments | Level 1
Assets
Total assets at fair value		$ 3,526,337