Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items]
Cash, Uninsured Amount	$ 134,800,000
Restricted Cash	8,040,870		$ 18,005,661
Increase in Restricted Cash	8,000,000		18,000,000
Allowance for Doubtful Accounts Receivable, Current	$ 725,356		$ 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.
Warrant Liability [Member]
Summary Of Significant Accounting Policies [Line Items]
Share Price		$ 10.00
Percentage For Down round financing		0.00%
Derivative Asset, Noncurrent		$ 5,500,000
Maximum
Summary Of Significant Accounting Policies [Line Items]
Restricted Cash Interest Rate	0.10%
Maximum | Warrant Liability [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected term		3 years 9 months
Risk free interest rate		1.60%
Expected volatility rate		39.10%
Minimum
Summary Of Significant Accounting Policies [Line Items]
Restricted Cash Interest Rate	0.05%
Minimum | Warrant Liability [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected term		3 years 3 months 14 days
Risk free interest rate		1.50%
Expected volatility rate		38.90%
APA ACO [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated Revenue Percentage	100.00%