Revenue - Summary of Revenue Disaggregated by Sales Channel and Major Products and Services (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation Of Revenue [Line Items]
Total revenue	$ 155,530	$ 102,009	$ 308,825	$ 250,103
Subscription Advertising and Digital Solutions
Disaggregation Of Revenue [Line Items]
Total revenue	128,733	79,449	254,179	196,712
Display Advertising
Disaggregation Of Revenue [Line Items]
Total revenue	21,322	16,558	43,279	39,917
Pay Per Lead
Disaggregation Of Revenue [Line Items]
Total revenue	3,280	4,769	7,040	10,512
Other
Disaggregation Of Revenue [Line Items]
Total revenue	$ 2,195	$ 1,233	$ 4,327	$ 2,962