Subsequent Events (Details)				12 Months Ended
	Feb. 25, 2019 USD ($)	Jan. 24, 2019 USD ($) $ / T	Oct. 03, 2017 USD ($)	Dec. 31, 2018 USD ($)	Apr. 03, 2021
Subsequent Event [Line Items]
Value of stock issued for purchase of membership interest				$ 369,000
Subsequent Event | Downtown Silver Springs LLC, General Partner
Subsequent Event [Line Items]
Right to receive carried interest percentage of general partner from sale of property	3.00%
Subsequent Event | Comstock Industrial LLC, General Partner
Subsequent Event [Line Items]
Right to receive carried interest percentage of general partner from sale of property	3.00%
Tonogold Agreement | Scenario, Forecast | Subsequent Event
Subsequent Event [Line Items]
Proceeds from sale of wholly-owned subsidiary		$ 15,000,000
Tonogold Agreement | Scenario, Forecast | Lucerne Property | Subsequent Event
Subsequent Event [Line Items]
Net smelter return percentage		1.50%
Tonogold Agreement | Scenario, Forecast | Storey County, Nevada | Subsequent Event
Subsequent Event [Line Items]
Net smelter return percentage		3.00%
Net smelter return royalty percentage, after year one		1.50%
Term of mineral lease		10 years
Annual costs incurred to explore, develop and mine properties		$ 100,000
Exploration and development work commitments		$ 200,000
Renewal term of mineral lease		10 years
Tonogold Option Agreement | Scenario, Forecast | American Flat Property | Subsequent Event | Phase 1
Subsequent Event [Line Items]
Annual reimbursements under facility lease		$ 1,100,000
Annual rental income under processing facility		$ 1,000,000
Rental fee per ton processed | $ / T		1
Potential rental income under processing facility lease		$ 15,000,000
Tonogold Option Agreement | Scenario, Forecast | American Flat Property | Subsequent Event | Phase 2
Subsequent Event [Line Items]
Annual rental income under processing facility		$ 1,000,000
Rental fee per ton processed | $ / T		0.50
Potential rental income under processing facility lease		$ 10,000,000
Tonogold Resources, Inc. | Lucerne Property
Subsequent Event [Line Items]
Option payments			$ 2,200,000
Tonogold Resources, Inc. | Lucerne Property | Land Improvements
Subsequent Event [Line Items]
Future spending commitments			$ 20,000,000
Tonogold Resources, Inc. | Comstock Mining LLC | Scenario, Forecast
Subsequent Event [Line Items]
Percentage interest in subsidiary					51.00%
Downtown Silver Springs, LLC | Subsequent Event
Subsequent Event [Line Items]
Proceeds from sale of property	$ 2,500,000
Comstock Industrial LLC | Subsequent Event
Subsequent Event [Line Items]
Proceeds from sale of property	$ 7,200,000
First alternative | Tonogold Agreement | Scenario, Forecast | Subsequent Event
Subsequent Event [Line Items]
Proceeds from sale of wholly-owned subsidiary		10,000,000
Remainder payment		5,000,000
Second alternative | Tonogold Agreement, Alternate Arrangement | Scenario, Forecast | Subsequent Event
Subsequent Event [Line Items]
Proceeds from sale of wholly-owned subsidiary		11,500,000
Second alternative | Tonogold Resources, Inc. | Tonogold Agreement, Alternate Arrangement | Scenario, Forecast | Subsequent Event
Subsequent Event [Line Items]
Value of stock issued for purchase of membership interest		$ 1,750,000