Derivative at Fair Value (Details) $ in Thousands			3 Months Ended
Dec. 03, 2019 $ / item	Dec. 02, 2019 $ / item	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Variable fee (per tonne) \| $ / item	11.00	22.00
Derivative at fair value			$ 39	$ 254
Deferred Revenue			135	$ 180
Decrease in derivatives			(215)
Plant Lease [Member]
Deferred Revenue			$ 45

Represents the per tonne charge under the lease arrangement.

No definition available.

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Namespace Prefix:	aumn_
Data Type:	srt-types:perUnitItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of deferred income and obligation to transfer product and service to customer for which consideration has been received or is receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(5))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The increase (decrease) during the period in the carrying value of derivative instruments reported as assets that are due to be disposed of within one year (or the normal operating cycle, if longer).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=aumn_PlantLeaseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: