Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended			9 Months Ended		12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items]
Cash, Uninsured Amount		$ 146,300,000		$ 146,300,000
Restricted Cash		4,218,176		4,218,176		$ 18,005,661
Increase in Restricted Cash						18,000,000
Allowance for Doubtful Accounts Receivable, Current		719,938		$ 719,938		$ 407,953
Equity Method Investment, Significant Influence Description				Significant influence is generally deemed to exist if the Company has an ownership interest in the voting stock of the investee of between 20% and 50%, although other factors, such as representation on the investee’s board of directors, are considered in determining whether the equity method of accounting is appropriate.
Payments of Dividends				$ 16,725,799	$ 9,490,632
Impairment of Intangible Assets, Finite-lived				0	0
Goodwill and Intangible Asset Impairment				0	0
Equity Method Investment, Impairment		$ 0	$ 0	$ 0	$ 0
Variable Interest Entity Percentage				50.00%
Warrant Liability [Member]
Summary Of Significant Accounting Policies [Line Items]
Risk free interest rate					1.62%
Share Price		$ 9.75		$ 9.75
Percentage For Down round financing					0.00%
Derivative Asset, Noncurrent			$ 5,100,000		$ 5,100,000
Maximum
Summary Of Significant Accounting Policies [Line Items]
Restricted Cash Interest Rate		0.10%		0.10%
Maximum | Warrant Liability [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected term					3 years 6 months
Expected volatility rate					39.87%
Minimum
Summary Of Significant Accounting Policies [Line Items]
Restricted Cash Interest Rate		0.05%		0.05%
Minimum | Warrant Liability [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected term					3 years 14 days
Expected volatility rate					38.72%
APA ACO [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated Revenue Percentage				100.00%
Network Medical Management, Inc. [Member]
Summary Of Significant Accounting Policies [Line Items]
Dividends Paid				$ 13,783,799
Network Medical Management, Inc. [Member] | Scenario, Forecast [Member]
Summary Of Significant Accounting Policies [Line Items]
Payments of Dividends	$ 4,216,201