Summary of Significant Accounting Policies - Liquidity (Details) - USD ($) $ in Thousands	1 Months Ended			3 Months Ended		12 Months Ended
	Feb. 29, 2020	Oct. 31, 2019	Oct. 31, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Cash and cash equivalents				$ 29,505	$ 99,114	$ 29,505	$ 43,531	$ 95,615
Long-term debt				53,646		53,646	53,464
Remaining amount available to borrow				0		$ 0
Aggregate minimum liquidity balance				10,000
Aggregate minimum liquidity balance at quarter end				20,000
Net losses				20,145	5,275
Operating cash flows				(12,604)	5,138
Purchases of property and equipment				$ 1,611	$ 1,734
Repayment of outstanding debt		$ 28,900	$ 41,400
Decline in net revenue, as a percent				28.00%	28.00%	32.00%
Expected annual savings	$ 8,000
Reduction in product, technology, general and administrative expenses				$ 4,900	$ 10,300
Reduction in product, technology, general and administrative expenses, as a percent				13.00%	21.00%
Decline in marketing expense						47.00%
Reduction in capital expenditures						$ 6,600
Reduction in capital expenditures, as a percent						56.00%
Letter of credit
Significant Accounting Policies [Line Items]
Outstanding borrowings in long term debt				$ 300		$ 300
Revolving credit facility
Significant Accounting Policies [Line Items]
Outstanding borrowings in long term debt				$ 54,678		$ 54,678	54,678
Remaining amount available to borrow							$ 0