Organization and Summary of Significant Accounting Policies (Details)		3 Months Ended
	Aug. 31, 2016 Subsidiary	Mar. 31, 2018 USD ($) Aircraft Lease	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)
Organization and Summary of Significant Accounting Policies [Abstract]
Number of wholly owned subsidiaries | Subsidiary	2
Capital Leased Assets [Line Items]
Notes payable and accrued interest		$ 133,768,100		$ 145,598,200
Finance Leases [Abstract]
Number of aircraft with sales type finance leases | Aircraft		6
Number of aircraft with direct financing leases | Aircraft		3
Number of finance leases | Lease		9
Interest earned on finance lease		$ 379,000	$ 325,400
Recent Accounting Pronouncements [Abstract]
Federal corporate tax rate		21.00%
SPE Financing [Member]
Capital Leased Assets [Line Items]
Notes payable and accrued interest		$ 12,474,200		13,535,300
Credit Facility [Member]
Capital Leased Assets [Line Items]
Notes payable and accrued interest		123,111,100		134,278,900
Recurring [Member]
Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis [Abstract]
Money market funds included in cash and cash equivalents		3,153,300		6,151,900
Liabilities recorded at fair value		0		$ 0
Aircraft [Member] | Held for Lease [Member]
Capital Leased Assets [Line Items]
Impairment charge		$ 0	$ 0