Variable Interest Entities (VIEs) (Details) - USD ($) $ in Thousands		Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents		$ 293,921		$ 288,027	$ 234,223
Investment in marketable securities		3,789		5,567
Other receivables		1,201		1,834
Prepaid expenses and other current assets		15,087		14,798
Total current assets		465,063		428,125
Non-current assets
Intangible assets, net		74,421		76,861
Goodwill		274,029		269,053
Income taxes receivable, non-current		15,943		15,943
Investments in other entities – equity method		45,831	$ 43,108	40,299	43,820	$ 44,383	$ 41,715
Operating lease right-of-use assets		17,905		20,444
Other assets		7,229		6,056
Total non-current assets		562,113		538,088
Total assets	[1]	1,027,176		966,213
Current liabilities
Accounts payable and accrued expenses		49,904		49,562
Fiduciary accounts payable		8,603		8,065
Medical liabilities		100,047		81,255	$ 112,499		$ 55,783
Dividends payable		638		664
Amount due to affiliate		3,246		3,304
Current portion of long-term debt		2,630		619
Finance lease liabilities		591		594
Operating lease liabilities		3,027		3,572
Total current liabilities		185,794		148,610
Non-current liabilities
Long-term debt, net of current portion and deferred financing costs		205,136		203,389
Deferred tax liability		12,335		14,217
Finance lease liabilities, net of current portion		1,078		1,275
Operating lease liabilities, net of current portion		17,852		19,915
Other long-term liabilities		21,383		20,260
Total non-current liabilities		257,784		259,056
Total liabilities	[1]	443,578		407,666
Nonrelated Party
Current assets
Receivables, net		66,927		49,631
Loans receivable		973		996
Related Party
Current assets
Receivables, net		82,820		65,147
Loans receivable		0		2,125
Variable Interest Entity, Primary Beneficiary
Current assets
Cash and cash equivalents		79,598		97,669
Investment in marketable securities		1,068		4,543
Income taxes receivable		0		8,580
Other receivables		586		1,236
Prepaid expenses and other current assets		9,211		9,289
Amount due from affiliates		0		30,340
Total current assets		182,328		227,497
Non-current assets
Land, property, and equipment, net		121,310		106,486
Intangible assets, net		49,439		53,964
Goodwill		110,182		111,539
Income taxes receivable, non-current		15,943		15,943
Investment in affiliates		325,457		304,755
Investments in other entities – equity method		32,222		27,561
Investment in privately held entities		405		405
Operating lease right-of-use assets		4,906		6,503
Other assets		4,099		4,169
Total non-current assets		663,963		631,325
Total assets		846,291		858,822
Current liabilities
Accounts payable and accrued expenses		22,014		23,632
Fiduciary accounts payable		8,603		7,853
Medical liabilities		42,923		48,100
Income taxes payable		13,100		0
Dividends payable		638		638
Amount due to affiliate		5,428		0
Current portion of long-term debt		630		619
Finance lease liabilities		591		594
Operating lease liabilities		1,463		1,800
Total current liabilities		95,390		83,236
Non-current liabilities
Long-term debt, net of current portion and deferred financing costs		27,922		26,645
Deferred tax liability		2,467		4,591
Finance lease liabilities, net of current portion		1,078		1,275
Operating lease liabilities, net of current portion		6,062		7,484
Other long-term liabilities		8,680		8,542
Total non-current liabilities		46,209		48,537
Total liabilities		141,599		131,773
Variable Interest Entity, Primary Beneficiary | Nonrelated Party
Current assets
Receivables, net		15,187		11,503
Loans receivable		0		22
Variable Interest Entity, Primary Beneficiary | Related Party
Current assets
Receivables, net		76,678		62,190
Loans receivable		$ 0		$ 2,125

[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 $520.8 million and $523.7 million as of June 30, 2023 and December 31, 2022, 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 $136.2 million and $131.8 million as of June 30, 2023 and December 31, 2022, respectively. The VIE balances do not include $325.5 million of investment in affiliates and $5.4 million of amounts due to affiliates as of June 30, 2023 and $304.8 million of investment in affiliates and $30.3 million of amounts due from affiliates as of December 31, 2022 as these are eliminated upon consolidation and not presented within the consolidated balance sheets. See Note 16 — “Variable Interest Entities (VIEs)” for further detail.