Summary of Significant Accounting Policies - Additional Information (Details)	8 Months Ended	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2020 USD ($) segment ReportingUnit	Dec. 31, 2019 USD ($) segment ReportingUnit	Dec. 31, 2018 USD ($) segment ReportingUnit
Accounting Policies [Line Items]
Variable interest entity's percentage of total assets and liabilities		1.00%	1.00%
Number of operating segments | segment		1
Property and equipment, depreciation description		Depreciation is computed using the straight-line method over the estimated useful lives of the assets
Number of reporting unit tested for goodwill impairment | ReportingUnit		1	1	1
Goodwill impairment		$ 0	$ 0	$ 0
Recognized loss of abandonment and impairment of operating lease assets		1,000,000
Impairment of long-lived assets			0	0
Advertising costs		222,400,000	163,700,000	$ 89,300,000
Comprehensive income		$ 0	0
Change in accounting principle accounting standards update adoption date		Jan. 01, 2020
Change in accounting principle, accounting standards update, immaterial effect [true false]		true
Change in accounting principle, accounting standards update, adopted [true false]		true
Accounting standards update [Extensible List]		us-gaap:AccountingStandardsUpdate201813Member
Subscription Revenue
Accounting Policies [Line Items]
Deferred revenue	$ 3,200,000	$ 5,300,000	3,200,000
Pharmaceutical Manufacturers Revenue
Accounting Policies [Line Items]
Deferred revenue	300,000	$ 1,500,000	300,000
Capitalized Software Costs
Accounting Policies [Line Items]
Intangible asset, amortization method		amortized on a straight-line basis over their estimated useful life
Intangible asset useful life		3 years
Furniture and Fixtures
Accounting Policies [Line Items]
Useful life of assets		5 years
Computer Equipment
Accounting Policies [Line Items]
Useful life of assets		3 years
Money Market Funds | Fair Value, Inputs, Level 1
Accounting Policies [Line Items]
Cash equivalents, fair value disclosure	$ 0	$ 932,500,000	$ 0
Customer Concentration Risk | Revenue From Customer
Accounting Policies [Line Items]
Number of customers | segment		3	2	3
Customer Concentration Risk | Revenue From Customer | Customer One
Accounting Policies [Line Items]
Concentration risk percentage		17.00%	24.00%	27.00%
Customer Concentration Risk | Revenue From Customer | Customer Two
Accounting Policies [Line Items]
Concentration risk percentage		14.00%	23.00%	19.00%
Customer Concentration Risk | Revenue From Customer | Customer Three
Accounting Policies [Line Items]
Concentration risk percentage		11.00%		15.00%
Credit Concentration Risk | Accounts Receivable
Accounting Policies [Line Items]
Number of customers | segment		1	2
Credit Concentration Risk | Accounts Receivable | Customer One
Accounting Policies [Line Items]
Concentration risk percentage		12.00%	17.00%
Credit Concentration Risk | Accounts Receivable | Customer Two
Accounting Policies [Line Items]
Concentration risk percentage			16.00%
Maximum
Accounting Policies [Line Items]
Variable interest entity's percentage of total revenue	1.00%	2.00%