Variable Interest Entities (VIEs) (Details) - USD ($)	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 52,726,305		$ 106,891,503	$ 101,132,237
Restricted cash	3,537,470		0
Investment in marketable securities	1,149,828		1,127,102
Receivables, net	16,707,314		7,127,217
Receivables, net – related party	64,057,647		49,328,739
Prepaid expenses and other current assets	10,121,935		7,385,098
Loan receivable – related parties	6,425,000		0
Total current assets	167,625,710		172,862,792
Noncurrent assets
Land, property and equipment, net	12,101,373		12,721,082
Intangible assets, net	109,069,858		86,875,883
Goodwill	209,313,824		185,805,880
Loans receivable – related parties	17,500,000		17,500,000
Investments in other entities – equity method	35,903,041		34,876,980
Restricted cash	740,212		745,470
Right-of-use assets	14,319,371	$ 14,300,000	0
Other assets	1,351,576		1,205,962
Total noncurrent assets	400,704,255		340,136,257
Total assets	568,329,965		512,999,049
Current liabilities
Accounts payable and accrued expenses	30,658,273		25,075,489
Fiduciary accounts payable	1,798,807		1,538,598
Medical liabilities	42,942,898		33,641,701		$ 63,972,318
Bank loan	0		40,257
Lease liabilities	2,836,010		0
Capital lease obligations	101,741		101,741
Total current liabilities	78,337,729		72,019,647
Noncurrent liabilities
Deferred tax liability	26,651,678		19,615,935
Fiduciary accounts payable	1,185,025		1,185,025
Lease liabilities	11,416,750		0
Capital lease obligations	466,771		517,261
Total noncurrent liabilities	84,320,224		34,318,221
Total liabilities	162,657,953		106,337,868
Variable Interest Entity, Primary Beneficiary
Current assets
Cash and cash equivalents	23,985,866		71,726,342
Restricted cash	3,537,470		0
Investment in marketable securities	1,074,280		1,066,103
Receivables, net	14,612,603		3,904,586
Receivables, net – related party	54,309,170		45,258,916
Prepaid expenses and other current assets	6,263,045		3,647,654
Loan receivable – related parties	6,425,000		0
Total current assets	110,207,434		125,603,601
Noncurrent assets
Land, property and equipment, net	9,191,430		9,602,228
Intangible assets, net	83,395,176		58,984,420
Goodwill	79,721,384		56,213,450
Loans receivable – related parties	12,500,000		12,500,000
Investment in a privately held entity that does not report net asset value per share	4,725,000		4,725,000
Investments in other entities – equity method	36,060,869		26,707,404
Restricted cash	740,212		745,470
Right-of-use assets	3,989,196		0
Other assets	1,063,164		839,085
Total noncurrent assets	231,386,431		170,317,057
Total assets	341,593,865		295,920,658
Current liabilities
Accounts payable and accrued expenses	6,982,147		6,378,751
Fiduciary accounts payable	1,798,807		1,538,598
Medical liabilities	36,756,473		24,983,110
Income taxes payable	0		11,621,861
Amount due to affiliate	13,084,786		11,505,680
Bank loan	0		40,257
Lease liabilities	837,984		0
Capital lease obligations	101,741		101,741
Total current liabilities	59,561,938		56,169,998
Noncurrent liabilities
Lines of credit	39,600,000		0
Deferred tax liability	21,383,614		15,693,159
Fiduciary accounts payable	1,185,025		1,185,025
Lease liabilities	3,073,114
Capital lease obligations	466,771		517,261
Total noncurrent liabilities	65,708,524		17,395,445
Total liabilities	$ 125,270,462		$ 73,565,443