Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 0	$ 0
Net income	$ 12,037,253	$ (13,198,878)

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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