Variable Interest Entities (VIEs) (Details) - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents		$ 334,796	$ 293,807	$ 274,613
Investment in marketable securities		2,490	2,498
Income taxes receivable		0	10,657
Other receivables		1,783	1,335
Prepaid expenses and other current assets		17,281	17,450
Total current assets		538,810	461,507
Non-current assets
Intangible assets, net		119,707	71,648
Goodwill		410,267	278,831
Income taxes receivable, non-current		15,943	15,943
Investments in other entities – equity method		35,893	25,774	43,108	$ 40,299
Operating lease right-of-use assets		39,152	37,396
Other assets		4,067	1,877
Total non-current assets		687,467	471,854
Total assets	[1]	1,226,277	933,361
Current liabilities
Accounts payable and accrued expenses		146,473	59,949
Fiduciary accounts payable		7,792	7,737
Medical liabilities		136,494	106,657	$ 98,396	$ 81,255
Dividend payable		638	638
Finance lease liabilities		636	646
Operating lease liabilities		5,007	4,607
Current portion of long-term debt		20,750	19,500
Other liabilities		31,960	18,940
Total current liabilities		355,272	218,674
Non-current liabilities
Finance lease liabilities, net of current portion		1,015	1,033
Operating lease liabilities, net of current portion		37,716	36,289
Deferred tax liability		3,756	4,072
Other long-term liabilities		7,652	3,586
Total non-current liabilities		418,587	303,919
Total liabilities	[1]	773,859	522,593
Nonrelated Party
Current assets
Receivables, net		120,106	76,780
Related Party
Current assets
Receivables, net		62,354	58,980
Variable Interest Entity, Primary Beneficiary
Current assets
Cash and cash equivalents		212,134	184,078
Investment in marketable securities		50	0
Income taxes receivable		0	1,600
Other receivables		997	454
Prepaid expenses and other current assets		11,891	9,991
Total current assets		334,111	275,950
Non-current assets
Land, property and equipment, net		5,084	5,306
Intangible assets, net		85,058	60,906
Goodwill		236,961	140,157
Income taxes receivable, non-current		15,943	15,943
Investments in other entities – equity method		12,560	12,114
Investment in affiliates		299,502	273,182
Investment in a privately held entity		405	405
Restricted cash		40	40
Operating lease right-of-use assets		26,082	28,796
Other assets		1,214	1,149
Total non-current assets		682,849	537,998
Total assets		1,016,960	813,948
Current liabilities
Accounts payable and accrued expenses		44,058	32,707
Fiduciary accounts payable		7,792	7,737
Medical liabilities		69,611	55,157
Dividend payable		638	638
Income tax payable		8,431	0
Finance lease liabilities		602	646
Operating lease liabilities		3,092	3,305
Current portion of long-term debt		0	8,542
Amount due to affiliates		110,117	107,340
Other liabilities		9,387	0
Total current liabilities		253,728	216,072
Non-current liabilities
Finance lease liabilities, net of current portion		905	1,033
Operating lease liabilities, net of current portion		26,186	28,675
Deferred tax liability		7,166	7,284
Other long-term liabilities		1,690	230
Total non-current liabilities		35,947	37,222
Total liabilities		289,675	253,294
Variable Interest Entity, Primary Beneficiary | Nonrelated Party
Current assets
Receivables, net		47,169	21,120
Variable Interest Entity, Primary Beneficiary | Related Party
Current assets
Receivables, net		$ 61,870	$ 58,707

[1] The Company’s condensed consolidated balance sheets include the assets and liabilities of its consolidated VIEs. The condensed consolidated balance sheets include total assets that can be used only to settle obligations of the Company’s consolidated VIEs totaling $717.5 million and $540.8 million as of March 31, 2024 and December 31, 2023, 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 $179.6 million and $146.0 million as of March 31, 2024 and December 31, 2023, respectively. These VIE balances do not include $299.5 million of investment in affiliates and $110.1 million of amounts due to affiliates as of March 31, 2024, and $273.2 million of investment in affiliates and $107.3 million of amounts due to affiliates as of December 31, 2023, as these are eliminated upon consolidation and not presented within the condensed consolidated balance sheets. See Note 16 — “Variable Interest Entities (VIEs)” for further details.