Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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For banks and other depository institutions: Includes cash on hand (currency and coin), cash items in process of collection, noninterest bearing deposits due from other financial institutions (including corporate credit unions), and noninterest bearing balances with the Federal Reserve Banks, Federal Home Loan Banks and central banks.

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Cash and Cash Equivalents - Summary of Cash and Cash Equivalents (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash And Cash Equivalents [Line Items]
Cash at bank and in hand	$ 36,778,028	$ 204,008,828
Cash equivalents	26,173,579	25,651,320
Cash and cash equivalents	62,951,607	229,660,148	$ 83,948,770	$ 13,160,696
Denominated in US$
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	58,253,341	224,878,393
Denominated in RMB
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	3,916,262	3,927,163
Denominated in Hong Kong dollar
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	19,890
Denominated in Australia dollar
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	$ 762,114	$ 854,592