Interest Rate Swap Agreement	6 Months Ended
Interest Rate Swap Agreement	Jun. 30, 2023
Interest Rate Swap Agreement [Abstract]
Interest Rate Swap Agreement	6. Interest Rate Swap Agreement The Company is exposed to certain risks relating to its ongoing business operations. The primary risk managed by using derivative instruments is interest rate risk. The Company utilizes an interest rate swap agreement to effectively convert the Company’s $12,000 variable-rate debt issue to a fixed rate. Interest rate swaps are contracts in which a series of interest rate cash flows are exchanged over a prescribed period. The notional amount on which the interest payments are based ($12,000) is not exchanged. The interest rate swap provides that the Company pays the counterparty a fixed interest rate of 3.16% on the notional amount of $12,000. In exchange, the counterparty paid the Company a variable interest rate based on 59% of the U.S. Dollar one-month LIBOR rate on the notional amount. The variable interest rate changed to 59% of the daily simple Secured Overnight Financing Rate, or SOFR, plus a spread adjustment of 11.448 basis points upon the discontinuance of LIBOR in 2023. The intent is for the variable rate received from the swap counterparty to approximate the variable rate the Company pays to bondholders on its variable rate debt issue, resulting in a fixed rate being paid to the swap counterparty and reducing the Company’s interest rate risk. The Company’s net payment rate on the swap was 0.16% and 2.60% for the three months ended June 30, 2023 and 2022, respectively, and 0.30% and 2.75% for the six months ended June 30, 2023 and 2022, respectively. The interest rate swap agreement is classified as a financial derivative used for non-trading activities. The accounting standards regarding accounting for derivatives and hedging activities require companies to recognize all derivative instruments as either assets or liabilities at fair value on the balance sheet. In accordance with the standards, the interest rate swap is recorded on the balance sheet in other deferred credits at fair value (see Note 7). The Company uses regulatory accounting treatment rather than hedge accounting to defer the unrealized gains and losses on its interest rate swap. These unrealized gains and losses are recorded as a regulatory asset or regulatory liability. Based on current ratemaking treatment, the Company expects the unrealized gains and losses to be recognized in rates as a component of interest expense as the swap settlements occur. Swap settlements are recorded in the income statement with the hedged item as interest expense. Swap settlements resulted in the reclassification from regulatory assets to interest expense of $5 and $78 for the three months ended June 30, 2023 and 2022, respectively, and $19 and $168 for the six months ended June 30, 2023 and 2022, respectively. The overall swap result was a gain of $267 and $281 for the three months ended June 30, 2023 and 2022, respectively, and $140 and $775 for the six months ended June 30, 2023 and 2022, respectively. The Company expects to reclassify $(10) from regulatory assets to interest expense as a result of swap settlements over the next 12 months. The interest rate swap agreement contains provisions that require the Company to maintain a credit rating of at least BBB- with Standard & Poor’s. If the Company’s rating were to fall below this rating, it would be in violation of these provisions, and the counterparty to the derivative could request immediate payment if the derivative was in a liability position. On July 26, 2023, Standard & Poor’s affirmed the Company’s credit rating at A-, with a stable outlook and adequate liquidity. The Company’s interest rate swap was in a liability position as of June 30, 2023. If a violation due to credit rating, or some other default provision, were triggered on June 30, 2023, the Company would have been required to pay the counterparty approximately $600. The interest rate swap will expire on October 1, 2029. Other than the interest rate swap, the Company has no other derivative instruments.