Schedule of intangible assets (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	$ 132,727,000	$ 129,492,000
Finite-lived Intangible Assets, Impairment/Disposal	(3,235,000)	0
Accumulated Amortization	(40,942,442)	(24,632,951)
Intangible Assets, Net	103,533,558	108,094,049
Finite-lived Intangible Assets, Additions	14,984,000	3,235,000
Intangible Assets, Gross, Total, Ending Balance	144,476,000	132,727,000
Medicare License | Indefinite-lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	0
Finite-lived Intangible Assets, Impairment/Disposal	0
Accumulated Amortization	0
Intangible Assets, Net	1,994,000
Finite-lived Intangible Assets, Additions	1,994,000
Intangible Assets, Gross, Total, Ending Balance	$ 1,994,000	$ 0
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	$ 106,660,000	$ 106,660,000
Finite-lived Intangible Assets, Impairment/Disposal	0	0
Accumulated Amortization	(35,842,508)		$ (22,186,665)
Intangible Assets, Net	74,040,492	84,473,335
Finite-lived Intangible Assets, Additions	3,223,000	0
Intangible Assets, Gross, Total, Ending Balance	$ 109,883,000	106,660,000
Trade name
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)	20 years
Trade name | Finite-Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	$ 0
Finite-lived Intangible Assets, Impairment/Disposal	0
Accumulated Amortization	(4,212)
Intangible Assets, Net	1,006,788
Finite-lived Intangible Assets, Additions	1,011,000
Intangible Assets, Gross, Total, Ending Balance	$ 1,011,000	$ 0
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, Impairment/Disposal	0	0
Accumulated Amortization	(5,014,886)	(2,446,286)
Intangible Assets, Net	17,817,114	20,385,714
Finite-lived Intangible Assets, Additions	0	0
Intangible Assets, Gross, Total, Ending Balance	$ 22,832,000	$ 22,832,000
Member relationships [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)	12 years	7 years
Member relationships [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)	5 years	5 years
Member relationships [Member] | Finite-Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	$ 3,235,000	$ 0
Finite-lived Intangible Assets, Impairment/Disposal	(3,235,000)	0
Accumulated Amortization	(46,500)	0
Intangible Assets, Net	6,649,500	3,235,000
Finite-lived Intangible Assets, Additions	6,696,000	3,235,000
Intangible Assets, Gross, Total, Ending Balance	$ 6,696,000	3,235,000
Patient management platform [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life (Yrs)	5 years
Patient management platform [Member] | Finite-Lived Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible Assets, Gross, Total, Beginning Balance	$ 0
Finite-lived Intangible Assets, Impairment/Disposal	0
Accumulated Amortization	(34,336)
Intangible Assets, Net	2,025,664
Finite-lived Intangible Assets, Additions	2,060,000
Intangible Assets, Gross, Total, Ending Balance	$ 2,060,000	$ 0