Term Loan - Other (Details)		3 Months Ended
	Jan. 25, 2019 USD ($) item	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Apr. 30, 2016 USD ($)
Face amount	$ 5,000,000			$ 1,000,000
Interest rate (as a percent)	4.25%	4.50%	3.75%
Number of equal monthly payments of principal plus accrued interest | item	36
Interest expense		$ 42,000	$ 7,000
Prime rate | Maximum
Spread (as a percent)	1.00%