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Long- Term Debt to Affiliated Trust - Narrative (Details) - USD ($)
$ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2020
Dec. 31, 2000
Dec. 31, 1997
Debt Instrument [Line Items]      
Junior subordinated debenture owed to unconsolidated subsidiary trust $ 51.5   $ 51.5
Proceeds from the issuance of common trust securities     1.5
Payments for repurchase of trust preferred securities   $ 10.0  
Avista Corp [Member]      
Debt Instrument [Line Items]      
Noncontrolling interest, ownership percentage by parent 100.00%    
Trust Preferred Securities Subject to Mandatory Redemption [Member]      
Debt Instrument [Line Items]      
Proceeds from (repurchase of) trust preferred securities     $ 50.0
Debt instrument, description of variable rate basis LIBOR    
Debt instrument, basis spread on variable rate 0.875%