Indefinite-lived Intangible Assets and Goodwill - Goodwill (Details) - USD ($)	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Roll-forward of goodwill balance
Beginning balance	$ 1,870,924
Changes	0
Ending balance	1,870,924	$ 1,870,924
Impairment on goodwill	$ 0	$ 0