v3.20.4

Significant Accounting Policies and Basis of Presentation - Additional Information (Details) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 USD ($) FinancialInstitution | Dec. 31, 2019 USD ($) FinancialInstitution Customer | Dec. 31, 2018 USD ($) | Jan. 01, 2020 USD ($)
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Foreign currency gains (loss) | $ 1,300,000 | $ (200,000) | $ (500,000) |
Impairment of goodwill | 0 | 0 | 0 |
Impairment of intangible assets | 0 | 0 |  |
Impairment of capitalized licensed content assets | $ 0 | 0 |  |
Lessee, operating lease, existence of option to extend | true |  |  |
Lessee, operating lease, existence of option to terminate | true |  |  |
Advertising costs | $ 7,100,000 | 7,300,000 | 3,000,000.0 |
Cumulative-effect adjustment to accumulated deficit | $ 332,406,000 | 313,833,000 |  |
Change in accounting principle, accounting standards update, adopted [true false] | true |  |  |
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2020 |  |  |
Change in accounting principle, accounting standards update, immaterial effect [true false] | true |  |  |
Accounting Standards Update 2016-13 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Change in accounting principle, accounting standards update, adopted [true false] | true |  |  |
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2020 |  |  |
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment | Revision of Prior Period, Adjustment |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Cumulative-effect adjustment to accumulated deficit |  |  |  | $ 1,100,000
Accounting Standards Update 2019-02 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Change in accounting principle, accounting standards update, adopted [true false] | true |  |  |
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2020 |  |  |
Change in accounting principle, accounting standards update, immaterial effect [true false] | true |  |  |
Accounting Standards Update 2018-15 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Change in accounting principle, accounting standards update, adopted [true false] | true |  |  |
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2020 |  |  |
Change in accounting principle, accounting standards update, immaterial effect [true false] | true |  |  |
Accounting Standards Update 2018-13 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Change in accounting principle, accounting standards update, adopted [true false] | true |  |  |
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2020 |  |  |
Change in accounting principle, accounting standards update, immaterial effect [true false] | true |  |  |
Accounting Standards Update 2017-04 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Change in accounting principle, accounting standards update, adopted [true false] | true |  |  |
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2020 |  |  |
Change in accounting principle, accounting standards update, immaterial effect [true false] | true |  |  |
Accounting Standards Update 2019-04 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Change in accounting principle, accounting standards update, adopted [true false] | true |  |  |
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2020 |  |  |
Change in accounting principle, accounting standards update, immaterial effect [true false] | true |  |  |
Accounting Standards Update 2020-02 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Change in accounting principle, accounting standards update, adopted [true false] | true |  |  |
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2020 |  |  |
Change in accounting principle, accounting standards update, immaterial effect [true false] | true |  |  |
Accounting Standards Update 2020-03 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Change in accounting principle, accounting standards update, adopted [true false] | true |  |  |
Change in accounting principle, accounting standards update, adoption date | Jan. 01, 2020 |  |  |
Change in accounting principle, accounting standards update, immaterial effect [true false] | true |  |  |
Leasehold Improvements |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Property and equipment, estimated useful lives description | shorter of the lease term or their estimated useful lives, which range from five to ten years |  |  |
Website and Internal-Use Software |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Capitalized costs | $ 2,200,000 | 100,000 | 1,000,000.0 |
Amortized expenses | $ 500,000 | $ 1,600,000 | $ 2,000,000.0 |
Maximum |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Business combination measurement period from acquisition | 1 year |  |  |
Property and equipment, estimated useful lives | 5 years |  |  |
Maximum | Leasehold Improvements |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Property and equipment, estimated useful lives | 10 years |  |  |
Maximum | Website and Internal-Use Software |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Estimated useful life | 3 years |  |  |
Minimum |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Property and equipment, estimated useful lives | 18 months |  |  |
Minimum | Leasehold Improvements |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Property and equipment, estimated useful lives | 5 years |  |  |
Minimum | Website and Internal-Use Software |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Estimated useful life | 2 years |  |  |
Customer Concentration Risk | Net Accounts Receivable |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Number of customers accounted for 10% or more | Customer |  | 0 |  |
Customer 1 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Number of financial institutions which manage cash balances | FinancialInstitution | 2 | 2 |  |
Customer 2 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Number of financial institutions which manage cash balances | FinancialInstitution | 2 | 2 |  |
Customer H | Customer Concentration Risk | Net Accounts Receivable |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Concentration risk percentage | 11.00% |  |  |
Cash, Cash Equivalents and Short-term Investment | Customer 1 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Concentration risk percentage | 46.00% | 65.00% |  |
Cash, Cash Equivalents and Short-term Investment | Customer 2 |  |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |  |
Concentration risk percentage | 26.00% | 34.00% |  |

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