Long-Term Debt |
9 Months Ended |
|---|---|
Sep. 30, 2026 | |
| Debt Disclosure [Abstract] | |
| Long-Term Debt | NOTE 10. LONG-TERM DEBT Avista Corp. In May 2026, the Company issued and sold $90.0 million of 4.77 percent first mortgage bonds due in 2029 and $70.0 million of 6.10 percent first mortgage bonds due in 2056 pursuant to a bond purchase agreement with institutional investors in the private placement market. In August 2026, the Company issued and sold an additional $70.0 million of 6.10 percent first mortgage bonds due in 2056 under this bond purchase agreement. The net proceeds from the sale of the new bonds were used to refinance existing indebtedness and pay for utility capital expenditures. |