Stock Repurchase Program (Details) - Common Stock - USD ($)	3 Months Ended				12 Months Ended	17 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2018	Sep. 30, 2018	Feb. 21, 2018	Apr. 25, 2017
Equity, Class of Treasury Stock [Line Items]
Repurchased Amount	$ 1,862,215	$ 409,143	$ 2,717,871	$ 3,012,869	$ 8,002,098
Remaining authorized repurchase amount	$ 22,000,000.0				$ 22,000,000.0	$ 22,000,000.0
15 Million Authorization Expansion, Expiring April 25, 2019
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount								$ 15,000,000.0
15 Million Authorization, Expiring April 25, 2019 [Member]
Equity, Class of Treasury Stock [Line Items]
Repurchased Amount						$ 8,000,000.0
February 2018, 15 Million Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount							$ 15,000,000.0