Cash and Cash Equivalents (Tables)

12 Months Ended

Dec. 31, 2018

Cash And Cash Equivalents [Abstract]

Summary of Cash and Cash Equivalents

	As of December 31,
	2017		2018
	$		$
Cash at bank and in hand		204,008,828		36,778,028
Cash equivalents		25,651,320		26,173,579
		229,660,148		62,951,607
Denominated in:
US$		224,878,393		58,253,341
RMB (note (i))		3,927,163		3,916,262
Hong Kong dollar (”HK$"）		—		19,890
Australia dollar ("A$")		854,592		762,114
		229,660,148		62,951,607