Schedule of intangible assets (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	$ 144,476,000	$ 132,727,000
Finite-lived Intangible Assets, Additions	0	14,984,000
Finite-lived Intangible Assets, Impairment/Disposal	0	(3,235,000)
Intangible Assets, Gross, Total, Ending Balance	144,476,000	144,476,000	$ 132,727,000
Accumulated Amortization	(57,600,117)	(40,942,442)
Intangible Assets, Net	86,875,883	103,533,558
Medicare License | Indefinite-lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	1,994,000	0
Finite-lived Intangible Assets, Additions	0	1,994,000
Finite-lived Intangible Assets, Impairment/Disposal	0	0
Intangible Assets, Gross, Total, Ending Balance	1,994,000	1,994,000	0
Accumulated Amortization	0	0
Intangible Assets, Net	$ 1,994,000	$ 1,994,000
Network relationships | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)	15 years	15 years
Network relationships | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)	11 years	11 years
Network relationships | Finite-Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	$ 109,883,000	$ 106,660,000
Finite-lived Intangible Assets, Additions	0	3,223,000
Finite-lived Intangible Assets, Impairment/Disposal	0	0
Intangible Assets, Gross, Total, Ending Balance	109,883,000	109,883,000	106,660,000
Accumulated Amortization	(48,361,773)	(35,842,508)
Intangible Assets, Net	$ 61,521,227	$ 74,040,492
Trade name
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)	20 years	20 years
Trade name | Finite-Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	$ 1,011,000	$ 0
Finite-lived Intangible Assets, Additions	0	1,011,000
Finite-lived Intangible Assets, Impairment/Disposal	0	0
Intangible Assets, Gross, Total, Ending Balance	1,011,000	1,011,000	0
Accumulated Amortization	(54,763)	(4,212)
Intangible Assets, Net	$ 956,237	$ 1,006,788
Management contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)	15 years	15 years
Management contracts [Member] | Finite-Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	$ 22,832,000	$ 22,832,000
Finite-lived Intangible Assets, Additions	0	0
Finite-lived Intangible Assets, Impairment/Disposal	0	0
Intangible Assets, Gross, Total, Ending Balance	22,832,000	22,832,000	22,832,000
Accumulated Amortization	(7,447,581)	(5,014,886)
Intangible Assets, Net	$ 15,384,419	$ 17,817,114
Member relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)	12 years
Member relationships [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)		12 years
Member relationships [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)		5 years
Member relationships [Member] | Finite-Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	$ 6,696,000	$ 3,235,000
Finite-lived Intangible Assets, Additions	0	6,696,000
Finite-lived Intangible Assets, Impairment/Disposal	0	(3,235,000)
Intangible Assets, Gross, Total, Ending Balance	6,696,000	6,696,000	$ 3,235,000
Accumulated Amortization	(1,289,667)	(46,500)
Intangible Assets, Net	$ 5,406,333	6,649,500
Patient management platform [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)	5 years		5 years
Patient management platform [Member] | Finite-Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	$ 2,060,000	0
Finite-lived Intangible Assets, Additions	0	2,060,000
Finite-lived Intangible Assets, Impairment/Disposal	0	0
Intangible Assets, Gross, Total, Ending Balance	2,060,000	2,060,000	$ 0
Accumulated Amortization	(446,333)	(34,336)
Intangible Assets, Net	$ 1,613,667	$ 2,025,664