Summary of Significant Accounting Policies (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Assets:
Cash and money market accounts	$ 1,296,016	$ 2,521,050
Bank certificates of deposit	8,675,329
Interest rate swaps		40,209
Liabilities:
Interest rate swaps	57,216
Fair Value, Inputs, Level 1 [Member]
Assets:
Cash and money market accounts	1,296,016	2,521,050
Interest rate swaps
Liabilities:
Interest rate swaps
Fair Value, Inputs, Level 2 [Member]
Assets:
Cash and money market accounts
Bank certificates of deposit	8,675,329
Interest rate swaps		40,209
Liabilities:
Interest rate swaps	57,216
Fair Value, Inputs, Level 3 [Member]
Assets:
Cash and money market accounts
Interest rate swaps
Liabilities:
Interest rate swaps