Notes Payable and Accrued Interest, Activity (Details)		1 Months Ended	9 Months Ended
	Aug. 31, 2016 USD ($) Aircraft	Oct. 31, 2018 USD ($)	Sep. 30, 2018 USD ($) Asset	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Credit Facility [Abstract]
Principal payment			$ 24,200,000	$ 4,800,000
Special purpose financing [Abstract]
Notes payable and accrued interest			140,247,200		$ 145,598,200
SPE Financing [Member]
Special purpose financing [Abstract]
Principal			10,304,700		13,511,900
Interest rate	4.455%
Notes payable and accrued interest			10,321,300		13,535,300
SPE Financing [Member] | October 3, 2020 [Member]
Special purpose financing [Abstract]
Principal	$ 9,805,600
SPE Financing [Member] | November 7, 2020 [Member]
Special purpose financing [Abstract]
Principal	$ 9,804,300
SPE Financing [Member] | Regional Jet Aircraft [Member]
Special purpose financing [Abstract]
Number of aircraft purchased | Aircraft	2
Credit Facility [Member]
Credit Facility [Abstract]
Credit facility current borrowing capacity			$ 170,000,000
Date of expiration			May 31, 2019
Credit facility maximum borrowing capacity			$ 180,000,000
Unused amount of the credit facility			$ 39,200,000		$ 36,000,000
Number of assets held for sale | Asset			4
Borrowing base deficiency			$ 1,400,000
Weighted average interest rate on credit facility			5.61%		5.21%
Credit Facility [Member] | Subsequent Event [Member]
Credit Facility [Abstract]
Principal payment		$ 2,000,000