Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details)	1 Months Ended	3 Months Ended	6 Months Ended
	Apr. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($) segment unit	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | segment			1
Number of reportable segments | segment			1
Amount deposit accounts exceeded FDIC insured limit		$ 268,200,000	$ 268,200,000		$ 294,900,000
Marketable securities – certificates of deposit		67,200,000	67,200,000		67,637,000
Equity securities		119,900,000	119,900,000		36,200,000
Equity securities, FV-NI, unrealized gain		83,800,000	$ 83,800,000
Risk pool surplus or deficits, settlement period after risk pool performance year			18 months
Impairment of finite-lived intangible assets			$ 0	$ 0
Impairment of long-lived assets			$ 0	0
Number of main reporting units | unit			3
Impairment of goodwill			$ 0	0
Impairment of indefinite-lived intangible assets			0	$ 0
Goodwill		239,053,000	239,053,000		239,053,000
Fiduciary accounts payable		9,092,000	9,092,000		9,642,000
Payments received, monthly			8,000,000.0
Payments received		24,300,000	48,100,000
Payments received, revenue		14,100,000	31,200,000
Contract liabilities		29,594,000	29,594,000		12,988,000
Certificates of Deposit
Summary Of Significant Accounting Policies [Line Items]
Marketable securities – certificates of deposit		67,200,000	67,200,000		67,600,000
Universal Care Acquisition Partners, LLC | Universal Care Inc
Summary Of Significant Accounting Policies [Line Items]
Ownership interest disposed	48.90%
Contingent consideration, cash held in escrow	$ 15,600,000
Contingent consideration, preferred shares	6,400,000
Contingent consideration, fair value	22,000,000.0
APC | Universal Care Inc
Summary Of Significant Accounting Policies [Line Items]
Additional cash consideration entitled to be received	$ 15,700,000
Write off of additional proceeds		15,700,000	15,700,000
Universal Care Acquisition Partners, LLC | APC
Summary Of Significant Accounting Policies [Line Items]
Ownership interest	100.00%
Accounts Payable and Accrued Expenses
Summary Of Significant Accounting Policies [Line Items]
Accrued contract liability recognized			400,000
Other long-term liabilities | Interest rate swap | Cash flow hedges: | Derivatives designated as hedging instruments:
Summary Of Significant Accounting Policies [Line Items]
Derivative liability, fair value		$ 1,200,000	$ 1,200,000		$ 0
PMPM Managed Care Contract
Summary Of Significant Accounting Policies [Line Items]
Contract term			one year
Management Fee Income Contract
Summary Of Significant Accounting Policies [Line Items]
Contract term			10 years
CMS
Summary Of Significant Accounting Policies [Line Items]
Expected period of payment upon termination of agreement			30 days
Minimum | Certificates of Deposit
Summary Of Significant Accounting Policies [Line Items]
Short-term marketable securities, maturity period			4 months
Maximum | Certificates of Deposit
Summary Of Significant Accounting Policies [Line Items]
Short-term marketable securities, maturity period			24 months