Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021 USD ($) Segment	Dec. 31, 2020 USD ($)
Significant Accounting Policies [Line Items]
Allowance for doubtful accounts	$ 0	$ 0
Amortization period description	The amortization period begins with the first month of availability on our service.
Number of reporting unit | Segment	1
Impairment of goodwill	$ 0	0
Impairment of long-lived assets	0	0
Marketing and advertising costs	$ 31,300,000	31,200,000
Defined contribution plan percentage employee's matching contribution	50.00%
Defined contribution plan maximum annual matching contribution amount	$ 3,000
Impairment charges on cost method investments	$ 0	0
ASU 2021-08 [Member]
Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2021
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]	true
Defined Contribution Plan 401 (k) [Member]
Significant Accounting Policies [Line Items]
Defined contribution plan annual matching contribution amount	$ 300,000	$ 300,000
Website Development Costs and Other Software [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment	3 years
Minimum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment	3 years
License period or estimated useful life of media library	12 months
Percentage of interest in investments	20.00%
Maximum [Member]
Significant Accounting Policies [Line Items]
Estimated useful life of property and equipment	45 years
License period or estimated useful life of media library	90 months
Percentage of interest in investments	50.00%