Aircraft and Aircraft Engines Held for Lease or Sale (Details)	3 Months Ended			6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2018 USD ($) Aircraft	Jun. 30, 2018 USD ($)	Sep. 30, 2017 USD ($) Aircraft	Jun. 30, 2018 USD ($)	Sep. 30, 2018 USD ($) Aircraft	Sep. 30, 2017 USD ($)	Dec. 31, 2017 Aircraft
Aircraft and aircraft engines held for lease or sale [Abstract]
Number owned | Aircraft	13				13		13
Percentage of net book value	81.00%				81.00%		82.00%
Other income from unpaid maintenance reserves	$ 1,200		$ 1,700		$ 1,632,800	$ 2,300
Payment for equipment and acquisition costs related to aircraft purchased					22,702,900	32,063,100
Number of aircraft sold | Aircraft	3
Impairment charge	$ 2,673,300		68,800		2,971,500	523,100
Proceeds from the sale of parts					4,366,200	160,100
Gain (loss) on sale of aircraft and aircraft parts	(2,384,300)		3,500		(2,374,400)	$ (130,400)
Minimum future lease revenue payments receivable under noncancelable operating leases [Abstract]
Remainder of 2018	7,185,500				7,185,500
2019	28,381,100				28,381,100
2020	25,797,800				25,797,800
2021	18,696,400				18,696,400
2022	16,738,800				16,738,800
Thereafter	34,687,700				34,687,700
Total	$ 131,487,300				$ 131,487,300
Engines [Member]
Aircraft and aircraft engines held for lease or sale [Abstract]
Number owned | Aircraft	1				1		1
Percentage of net book value	1.00%				1.00%		1.00%
Turboprop Aircraft [Member]
Aircraft and aircraft engines held for lease or sale [Abstract]
Number owned | Aircraft	4				4		10
Percentage of net book value	18.00%				18.00%		17.00%
Held for Sale [Member] | Aircraft Parts [Member]
Aircraft and aircraft engines held for lease or sale [Abstract]
Impairment charge	$ 2,673,300
Number of assets held for lease | Aircraft	4
Proceeds from the sale of parts	$ 89,200		47,500
Accrued receivables	$ 92,400				$ 92,400
Gain (loss) on sale of aircraft and aircraft parts		$ 16,000	3,500
Decrease in accounts receivable		(41,100)
Decrease in carrying value of parts		$ (124,500)	(44,000)
Held for Lease [Member]
Aircraft and aircraft engines held for lease or sale [Abstract]
Other income from unpaid maintenance reserves				$ 1,629,000
Number of aircraft returned | Aircraft							3
Number of aircraft purchased | Aircraft	0
Held for Lease [Member] | Embraer 175 Aircraft [Member]
Aircraft and aircraft engines held for lease or sale [Abstract]
Payment for equipment and acquisition costs related to aircraft purchased			$ 10,557,400
Number of aircraft purchased | Aircraft			1
Held for Lease [Member] | Engines [Member]
Aircraft and aircraft engines held for lease or sale [Abstract]
Number of aircraft sold | Aircraft			2
Gain (loss) on sale of aircraft and aircraft parts			$ (173,700)
Held for Lease [Member] | Turboprop Aircraft [Member]
Aircraft and aircraft engines held for lease or sale [Abstract]
Number of aircraft sold | Aircraft	2
Gain (loss) on sale of aircraft and aircraft parts	$ (2,384,300)