Related-Party Transactions - Additional Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Apr. 30, 2020	Dec. 31, 2019 USD ($)	Nov. 28, 2018 USD ($) agreement	Jun. 28, 2018 USD ($)	Nov. 16, 2015 USD ($)
Related Party Transaction [Line Items]
Operating lease right-of-use assets	$ 19,298		$ 19,298			$ 14,248
Lease liabilities	19,906		19,906
Recognized risk pool revenue	5,474	$ 10,979	23,081	$ 37,858
NMM | Board Members
Related Party Transaction [Line Items]
Consulting services paid	0	27	100	200
NMM | LMA
Related Party Transaction [Line Items]
Revenue from related parties	4,200	12,600	4,400	12,900
APC | PMIOC | Service
Related Party Transaction [Line Items]
Payments to related parties	500	1,500	700	2,100
APC | DMG | Service
Related Party Transaction [Line Items]
Payments to related parties	1,200	3,800	2,000	5,800
Universal Care, Inc.
Related Party Transaction [Line Items]
Amount of subordinated note receivable agreement									$ 5,000
Universal Care Acquisition Partners, LLC
Related Party Transaction [Line Items]
Amount of subordinated note receivable agreement							$ 5,000	$ 2,500
Number of additional subordinated note receivable agreements | agreement							2
APC Shareholders | APC | Service
Related Party Transaction [Line Items]
Payments to related parties	7,100	6,700	23,400	23,100
Advance Diagnostic Surgery Center | APC | Service
Related Party Transaction [Line Items]
Payments to related parties	100	200	100	200
APC Shareholders and Officers | APC
Related Party Transaction [Line Items]
Payments to related parties	1,700	1,800	6,500	6,900
Medical Property Partners | NMM
Related Party Transaction [Line Items]
Payments to related parties	300	800	300	800
One MSO, Inc.
Related Party Transaction [Line Items]
Operating lease right-of-use assets	10,400		10,400
Lease liabilities	10,400		10,400
One MSO, Inc. | NMM
Related Party Transaction [Line Items]
Payments to related parties	400		1,100
Critical Quality Management Corp
Related Party Transaction [Line Items]
Payments to related parties	39	100	300	300
Numen LLC
Related Party Transaction [Line Items]
Operating lease right-of-use assets	1,400		1,400
Lease liabilities	1,400		1,400
Numen LLC | SCHC
Related Party Transaction [Line Items]
Payments to related parties	100	300	100	300
AHMC
Related Party Transaction [Line Items]
Recognized risk pool revenue	10,500	$ 31,500	11,000	$ 31,900
Amount outstanding under agreement	$ 36,900		$ 36,900			$ 40,400
Universal Care, Inc.
Related Party Transaction [Line Items]
Ownership interest									48.90%
Universal Care, Inc. | APC | Universal Care Acquisition Partners, LLC
Related Party Transaction [Line Items]
Ownership interest					48.90%
LMA | NMM
Related Party Transaction [Line Items]
Ownership interest	25.00%	25.00%	25.00%	25.00%
PMIOC | APC Shareholders | APC | Service
Related Party Transaction [Line Items]
Ownership interest	40.00%	40.00%	40.00%	40.00%
DMG | APC Shareholders | APC | Service
Related Party Transaction [Line Items]
Ownership interest	40.00%	40.00%	40.00%	40.00%
One MSO, Inc. | Dr. Sim And Dr. Lam
Related Party Transaction [Line Items]
Ownership interest	50.00%		50.00%