Variable Interest Entities (VIEs) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Current assets
Cash and cash equivalents	$ 80,892	$ 103,189	$ 93,008
Restricted cash	75	75
Investment in marketable securities	117,075	116,539
Receivables, net	18,012	11,004
Receivables, net – related party	50,911	48,136
Other receivables	16,362	16,885
Prepaid expenses and other current assets	11,811	10,315
Loans receivable	6,425	6,425
Loans receivable – related parties	16,500	16,500
Total current assets	318,063	329,068
Noncurrent assets
Intangible assets, net	98,840	103,012
Goodwill	238,539	238,505
Investments in other entities – equity method	30,781	28,427
Restricted cash	746	746
Operating lease right-of-use assets	18,199	14,248
Other assets	6,475	1,681
Total noncurrent assets	406,352	399,645
Total assets	724,415	728,713
Current liabilities
Accounts payable and accrued expenses	20,106	27,279
Fiduciary accounts payable	1,709	2,027
Dividend payable	337	271
Finance lease liabilities	102	102
Operating lease liabilities	3,119	2,990
Total current liabilities	106,605	105,423
Noncurrent liabilities
Deferred tax liability	16,332	18,269
Finance lease liabilities, net of current portion	390	416
Operating lease liabilities, net of current portion	15,583	11,373
Total noncurrent liabilities	262,410	262,230
Total liabilities	369,015	367,653
Variable Interest Entity, Primary Beneficiary
Current assets
Cash and cash equivalents	57,015	87,110
Restricted cash	75	75
Investment in marketable securities	117,036	123,948
Receivables, net	16,332	9,300
Receivables, net – related party	49,279	42,976
Other receivables	734	744
Prepaid expenses and other current assets	7,257	7,403
Loans receivable	6,425	6,425
Loans receivable – related parties	16,500	16,500
Total current assets	270,653	294,481
Noncurrent assets
Land, property and equipment, net	9,304	9,547
Intangible assets, net	78,247	81,439
Goodwill	108,946	108,913
Investment in privately held entities	223,796	319,930
Investments in other entities – equity method	30,785	28,427
Restricted cash	746	746
Operating lease right-of-use assets	4,444	4,751
Other assets	5,040	1,057
Total noncurrent assets	461,308	554,810
Total assets	731,961	849,291
Current liabilities
Accounts payable and accrued expenses	11,317	11,187
Fiduciary accounts payable	1,709	2,027
Medical liabilities	45,029	49,019
Income taxes payable	8,034	4,530
Amount due to affiliate	23,128	28,058
Dividend payable	337	271
Finance lease liabilities	102	102
Operating lease liabilities	1,217	1,088
Total current liabilities	90,873	96,282
Noncurrent liabilities
Deferred tax liability	12,587	14,059
Finance lease liabilities, net of current portion	390	416
Operating lease liabilities, net of current portion	3,336	3,742
Total noncurrent liabilities	16,313	18,217
Total liabilities	$ 107,186	$ 114,499