CONDENSED CONSOLIDATED STATEMENTS OF CAPITAL STOCK AND LONG-TERM DEBT (Unaudited) (Parenthetical) - shares shares in Thousands	9 Months Ended
Sep. 30, 2021	Dec. 31, 2020
Common Stock, Shares Authorized	40,000	40,000
Common Stock, Shares Outstanding	17,493	17,473
Preferred Stock, Shares Authorized	120	120
Preferred Stock, Shares Outstanding	20	20
Convertible Preferred Stock $7.00 Series [Member]
Preferred Stock, Shares Outstanding	10	10
Nonredeemable Preferred Stock $7.00 Series [Member]
Preferred Stock, Shares Outstanding	1	1
Nonredeemable Preferred Stock $4.75 Series [Member]
Preferred Stock, Shares Outstanding	10	10
First Mortgage Bonds due 2021-2059 [Member]
Long term debt maturity period	2021-2059
First Mortgage Bonds due 2021-2059 [Member] \| Minimum [Member]
Interest rate	0.00%
First Mortgage Bonds due 2021-2059 [Member] \| Maximum [Member]
Interest rate	5.50%
Amortizing Secured Notes due 2021-2040 [Member]
Long term debt maturity period	2021-2040
Amortizing Secured Notes due 2021-2040 [Member] \| Minimum [Member]
Interest rate	4.45%
Amortizing Secured Notes due 2021-2040 [Member] \| Maximum [Member]
Interest rate	8.05%
State Revolving Trust Notes due 2022-2038 [Member]
Long term debt maturity period	2022-2038
State Revolving Trust Notes due 2022-2038 [Member] \| Minimum [Member]
Interest rate	2.00%
State Revolving Trust Notes due 2022-2038 [Member] \| Maximum [Member]
Interest rate	4.22%
State Revolving Fund Bond due 2021 [Member]
Interest rate	0.00%
Long term debt maturity period	2021
Construction Loans [Member]
Interest rate	0.00%

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Disclosure of timing of required repayments, sinking fund requirements, and other redeemable securities at fixed or determinable prices and dates in the five years immediately following the date of the latest balance sheet presented in the financial statements, and the amount thereafter to fully repay the principal of long-term debt. These disclosures may be made either on an individual debt or security basis, by type of debt or security basis, or on a combined basis.

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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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