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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Amount of 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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Cash and Cash Equivalents - Summary of Cash and Cash Equivalents (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash And Cash Equivalents [Line Items]
Cash at bank and in hand	$ 204,008,828	$ 36,531,272
Cash equivalents	25,651,320	47,417,498
Cash and cash equivalents	229,660,148	83,948,770	$ 13,160,696	$ 7,152,274
Denominated in US$
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	224,878,393	77,463,141
Denominated in RMB
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	3,927,163	6,365,311
Denominated in Australia dollar
Cash And Cash Equivalents [Line Items]
Cash and cash equivalents	$ 854,592	$ 120,318