Deferred Revenue (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($) item	Dec. 31, 2019 USD ($)
Deferred Revenue
Cash received prior to fulfillment	$ 3,900	$ 3,205
Gift cards, prepaid orders, and other	1,873	2,915
Deferred revenue	$ 5,773	$ 6,120
Contract liabilities, number of types | item	2
Deferred revenue recognized during the period	$ 5,300