Commitments and Contingencies - Seperation Agreement (Details)			12 Months Ended
	Sep. 12, 2017 USD ($) installment shares	Sep. 05, 2017	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jul. 31, 2017 USD ($)
Other Commitments [Line Items]
Accrued salaries and wages			$ 1,083,644	$ 713,489	$ 1,701,359
Separation Agreement
Other Commitments [Line Items]
Expiration period of resignation revocation		7 days
Payments for accrued obligations	$ 1,130,000
Other commitments, payment period	3 days
Payments for postemployment benefits	$ 1,440,000
Options granted (in shares) | shares	948,000
Maximum period of advisement by former officer	12 months
Payments for other commitments			1,610,000
Accrued salaries and wages			$ 962,000
Separation Agreement | Minimum
Other Commitments [Line Items]
Number of installment payments | installment	1
Separation Agreement | Maximum
Other Commitments [Line Items]
Number of installment payments | installment	2