Available-for-Sale-Securities Schedule of Available-for-Sale Securities Reconciliation (Details) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 56,273,200	$ 4,426,800
Gross Unrealized Gains	100	0
Gross Unrealized Losses	(28,800)	0
Estimated Fair Value	56,244,500	4,426,800
Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	249,000	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	249,000	0
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	49,345,600	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(28,800)	0
Estimated Fair Value	49,316,800	0
Money Market Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,678,600	4,426,800
Gross Unrealized Gains	100	0
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 6,678,700	$ 4,426,800