Derivative liability - Movement (Details) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2020	Dec. 31, 2019
Derivative Liability Details 1
Opening Balance	$ 8,694,272	$ 4,618,080
Derivative liability arising from convertible notes		1,477,163
Fair value adjustment to derivative liability	9,754,896	2,599,029
Closing Balance	$ 18,449,168	$ 8,694,272

The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624258-113959

Name:	us-gaap_DerivativeNetLiabilityPositionAggregateFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant