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Commitment, Contingencies And Guarentees: Manufactured Gas Processing (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Regulatory assets	$ 278,258	$ 271,344
Environmental
Loss Contingencies [Line Items]
Regulatory assets	1,413	$ 1,454
Manufactured Gas Plant | Gas Utilities
Loss Contingencies [Line Items]
Insurance Settlements Receivable, Noncurrent	1,200
Manufactured Gas Plant | Gas Utilities | Black Hills Energy - Iowa Gas
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	2,600
Manufactured Gas Plant | Gas Utilities | Black Hills Energy - Nebraska Gas
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	600
Manufactured Gas Plant | Gas Utilities | Environmental
Loss Contingencies [Line Items]
Regulatory assets	$ 1,400

X

- Definition

Undiscounted amount of the accrual for environmental loss contingencies.

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Carrying amount due after one year of the balance sheet date (or one operating cycle, if longer) of amount due in settlement of a claim for reimbursement from an insurance company when the Company has suffered a loss covered under an insurance policy.

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