Transactions with Affiliates - Future Minimum Lease Commitment (Detail) - USD ($)	Sep. 30, 2019	Jan. 01, 2019
Operating Lease Liabilities, Payments Due
2019	$ 130,492
2020	529,800
2021	545,697
2022	276,882
Total Commitment	1,482,871
Operating Lease Liabilities, Discounted Cash Flows
2019	127,855
2020	513,143
2021	515,623
2022	257,305
Total Commitment	1,413,926
Present value of operating lease	$ 1,390,000
Operating lease, discount rate (as a percent)		2.23%
Operating lease, remaining term		42 months