Note 6 - Notes and Leases Payable - Summary of Note Payable (Details) (Parentheticals) - USD ($)	6 Months Ended	12 Months Ended
Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Note Payable Mining Equipment [Member]
Debt Instrument, Periodic Payment, Total	$ 1,339	$ 1,339	$ 1,339
Note Payable Insurance Company [Member] \| Minimum [Member]
Debt Instrument, Periodic Payment, Total	5,045	5,045	5,045
Note Payable Insurance Company [Member] \| Maximum [Member]
Debt Instrument, Periodic Payment, Total	$ 17,959	$ 17,959	$ 17,959

Amount of the required periodic payments including both interest and principal payments.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

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