Accrued Expenses and Other Liabilities - Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Deferred payment to Zoosk's shareholders	$ 11,249	$ 10,373
Lease liabilities, less current portion	4,364	4,650
Sublease security deposit	1,038	1,038
Other	1,469	1,480
Other liabilities	$ 18,120	$ 17,541