Property and equipment (Schedule of Impairement Charge) (Details)	3 Months Ended
Mar. 31, 2018 USD ($)
Property, Plant and Equipment [Line Items]
Impairment charge	$ 11,480,491
Prive Miners [Member]
Property, Plant and Equipment [Line Items]
Impairment charge	10,677,603
BMSS Miners [Member]
Property, Plant and Equipment [Line Items]
Impairment charge	406,652
Kairos Miners [Member]
Property, Plant and Equipment [Line Items]
Impairment charge	$ 396,236

For the asset that is reclassified back to held and used from held-for-sale, the amount of impairment charge that is recognized on the reclassification date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 35
-Paragraph 44
-URI http://asc.fasb.org/extlink&oid=29634951&loc=d3e1756-110224

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2459-110228

Name:	us-gaap_ImpairmentChargeOnReclassifiedAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration