Variable Interest Entities (VIEs) - Eliminated Upon Consolidation Included In Accompanying Consolidated Balance Sheets (Details) - USD ($) $ in Thousands		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents		$ 233,097	$ 193,470	$ 103,189
Investment in marketable securities		53,417	67,695
Receivables, net		10,608	7,058
Receivables, net – related party		69,376	49,260
Other receivables		9,647	4,297
Prepaid expenses and other current assets		18,637	16,797
Total current assets		398,782	338,577
Non-current assets
Intangible assets, net		82,807	86,985
Goodwill		253,039	239,053	$ 238,505
Investments in other entities – equity method		41,715	43,292
Restricted cash		0	500
Operating lease right-of-use assets		15,441	18,574
Other assets		5,928	18,915
Total non-current assets		453,581	478,909
Total assets	[1]	852,363	817,486
Current liabilities
Accounts payable and accrued expenses		43,951	36,143
Fiduciary accounts payable		10,534	9,642
Medical liabilities		55,783	50,330
Income taxes payable		652	4,224
Dividend payable		556	485
Finance lease liabilities		486	102
Operating lease liabilities		2,629	3,177
Operating lease liabilities		780	10,889
Total current liabilities		115,371	114,992
Non-current liabilities
Deferred tax liability		9,127	10,959
Finance lease liabilities, net of current portion		973	311
Operating lease liabilities, net of current portion		13,198	15,865
Long-term debt, net of current portion		182,917	230,211
Other long-term liabilities		14,777	0
Total non-current liabilities		220,992	257,346
Total liabilities	[1]	336,363	372,338
Variable Interest Entity, Primary Beneficiary
Current assets
Cash and cash equivalents		161,762	126,158
Investment in marketable securities		49,066	67,637
Receivables, net		7,251	5,155
Receivables, net – related party		62,180	46,718
Income taxes receivable		1,342	0
Other receivables		1,833	1,084
Prepaid expenses and other current assets		11,734	14,863
Loans receivable — related parties		4,000	0
Amounts due from affiliates*		6,598	0
Total current assets		305,766	261,615
Non-current assets
Land, property and equipment, net		49,547	27,599
Intangible assets, net		58,282	69,250
Goodwill		109,656	109,460
Loans receivable – related parties		89	4,145
Investment in affiliates		802,821	225,144
Investments in other entities – equity method		41,715	43,516
Investment in affiliates*		405	36,584
Restricted cash		0	500
Operating lease right-of-use assets		4,953	6,298
Other assets		3,219	17,177
Total non-current assets		1,070,687	539,673
Total assets		1,376,453	801,288
Current liabilities
Accounts payable and accrued expenses		11,591	12,963
Fiduciary accounts payable		10,534	9,642
Medical liabilities		44,000	37,684
Income taxes payable		0	4,225
Dividend payable		556	485
Amount due to affiliate*		0	22,698
Finance lease liabilities		110	102
Operating lease liabilities		1,250	1,242
Operating lease liabilities		780	201
Total current liabilities		68,821	89,242
Non-current liabilities
Deferred tax liability		1,982	9,144
Finance lease liabilities, net of current portion		193	311
Operating lease liabilities, net of current portion		3,950	5,242
Long-term debt, net of current portion		7,114	7,379
Other long-term liabilities		9,614	0
Total non-current liabilities		22,853	22,076
Total liabilities		$ 91,674	$ 111,318

[1] The Company’s consolidated balance sheets include the assets and liabilities of its consolidated VIEs. The consolidated balance sheets include total assets that can be used only to settle obligations of the Company’s consolidated VIEs totaling $567.0 million and $576.1 million as of December 31, 2021 and December 31, 2020, respectively, and total liabilities of the Company’s consolidated VIEs for which creditors do not have recourse to the general credit of the primary beneficiary of $91.7 million and $88.6 million as of December 31, 2021 and December 31, 2020, respectively. These VIE balances do not include $802.8 million of investment in affiliates and $6.6 million of amounts due from affiliates as of December 31, 2021 and $225.1 million of investment in affiliates and $22.7 million of amounts due to affiliates as of December 31, 2020 as these are eliminated upon consolidation and not presented within the consolidated balance sheets. See Note 18 – “Variable Interest Entities (VIEs)” for further detail.