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CONSOLIDATED STATEMENTS OF CAPITAL STOCK AND LONG-TERM DEBT (Parenthetical) - shares | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017
Common Stock, Shares Authorized | 40,000,000 | 40,000,000
Common Stock, Shares Outstanding | 16,403,000 | 16,352,000
Preferred Stock, Shares Authorized | 126,000 | 126,000
Preferred Stock, Shares Outstanding | 23,000 | 23,000
Convertible Preferred Stock $7.00 Series |  |
Common Stock, Shares Outstanding | 10,000 | 10,000
Convertible Preferred Stock $8.00 Series [Member] |  |
Common Stock, Shares Outstanding | 3,000 | 3,000
Nonredeemable Preferred Stock $7.00 Series |  |
Common Stock, Shares Outstanding | 1,000 | 1,000
Nonredeemable Preferred Stock $4.75 Series [Member] |  |
Common Stock, Shares Outstanding | 10,000 | 10,000
Amortizing Secured Note, due December 20, 2021 [Member] |  |
Due date of debt | Dec. 20, 2021 |
Interest rate | 8.05% |
Amortizing Secured Note, due May 19, 2028 [Member] |  |
Due date of debt | May 19, 2028 |
Interest rate | 6.25% |
Amortizing Secured Note, due August 25, 2030 [Member] |  |
Due date of debt | Aug. 25, 2030 |
Interest rate | 6.44% |
Amortizing Secured Note, due September 19, 2031 [Member] |  |
Due date of debt | Sep. 19, 2031 |
Interest rate | 6.46% |
State Revolving Trust Note, due December 31, 2022 [Member] |  |
Due date of debt | Dec. 31, 2022 |
Interest rate | 4.22% |
State Revolving Trust Note, due May 1, 2025 [Member] |  |
Due date of debt | May 01, 2025 |
Interest rate | 3.60% |
State Revolving Trust Note, due March 1, 2026 [Member] |  |
Due date of debt | Mar. 01, 2026 |
Interest rate | 3.30% |
State Revolving Trust Note2 [Member] |  |
Due date of debt | Jan. 25, 2027 |
Interest rate | 3.49% |
State Revolving Trust Note, due December 1, 2026 [Member] |  |
Due date of debt | Dec. 01, 2026 |
Interest rate | 4.03% |
State Revolving Trust Bond 4.00% to 5.00%, due August 1, 2021 [Member] |  |
Due date of debt | Aug. 01, 2021 |
State Revolving Trust Bond 4.00% to 5.00%, due August 1, 2021 [Member] | Minimum [Member] |  |
Interest rate | 4.00% |
State Revolving Trust Bond 4.00% to 5.00%, due August 1, 2021 [Member] | Maximum [Member] |  |
Interest rate | 5.00% |
State Revolving Trust Bond 0.00%, due August 1, 2021 [Member] |  |
Due date of debt | Aug. 01, 2021 |
Interest rate | 0.00% |
State Revolving Trust Note, due July 1, 2028 [Member] |  |
Due date of debt | Jul. 01, 2028 |
Interest rate | 3.64% |
State Revolving Trust Note, due January 1, 2028 [Member] |  |
Due date of debt | Jan. 01, 2028 |
Interest rate | 3.64% |
State Revolving Trust Note, due August 1, 2031 [Member] |  |
Due date of debt | Aug. 01, 2031 |
Interest rate | 3.45% |
Amortizing Secured Note, due April 20, 2029 [Member] |  |
Due date of debt | Apr. 20, 2029 |
Interest rate | 6.59% |
Amortizing Secured Note 7.05%, due January 20, 2030 [Member] |  |
Due date of debt | Jan. 20, 2030 |
Interest rate | 7.05% |
Amortizing Secured Note 5.69%, due January 20, 2030 [Member] |  |
Due date of debt | Jan. 20, 2030 |
Interest rate | 5.69% |
4.45%, Amortizing Secured Note, due April 20, 2040 [Member] |  |
Due date of debt | Apr. 20, 2040 |
Interest rate | 4.45% |
4.47%, Amortizing Secured Note, due April 20, 2040 [Member] |  |
Due date of debt | Apr. 20, 2040 |
Interest rate | 4.47% |
State Revolving Trust Note, due July 1, 2031 [Member] |  |
Due date of debt | Jul. 01, 2031 |
Interest rate | 3.75% |
State Revolving Trust Note, due February 1, 2036 [Member] |  |
Due date of debt | Feb. 01, 2036 |
Interest rate | 2.00% |
State Revolving Trust Note, due November 30, 2030 [Member] |  |
Due date of debt | Nov. 30, 2030 |
Interest rate | 3.75% |
Construction Loans [Member] |  |
Interest rate | 0.00% |
First Mortgage Bonds - Series X [Member] |  |
Due date of debt | Aug. 01, 2018 |
Interest rate | 0.00% |
First Mortgage Bonds - Series Y [Member] |  |
Due date of debt | Aug. 01, 2018 |
First Mortgage Bonds - Series Y [Member] | Minimum [Member] |  |
Interest rate | 4.25% |
First Mortgage Bonds - Series Y [Member] | Maximum [Member] |  |
Interest rate | 4.63% |
First Mortgage Bonds - Series Z [Member] |  |
Due date of debt | Aug. 01, 2019 |
Interest rate | 0.00% |
First Mortgage Bonds - Series AA [Member] |  |
Due date of debt | Aug. 01, 2019 |
First Mortgage Bonds - Series AA [Member] | Minimum [Member] |  |
Interest rate | 5.25% |
First Mortgage Bonds - Series AA [Member] | Maximum [Member] |  |
Interest rate | 5.75% |
First Mortgage Bonds - Series BB [Member] |  |
Due date of debt | Aug. 01, 2021 |
Interest rate | 0.00% |
First Mortgage Bonds - Series CC [Member] |  |
Due date of debt | Aug. 01, 2021 |
First Mortgage Bonds - Series CC [Member] | Minimum [Member] |  |
Interest rate | 4.00% |
First Mortgage Bonds - Series CC [Member] | Maximum [Member] |  |
Interest rate | 5.00% |
First Mortgage Bonds - Series EE [Member] |  |
Due date of debt | Aug. 01, 2023 |
Interest rate | 0.00% |
First Mortgage Bonds - Series FF [Member] |  |
Due date of debt | Aug. 01, 2024 |
First Mortgage Bonds - Series FF [Member] | Minimum [Member] |  |
Interest rate | 3.00% |
First Mortgage Bonds - Series FF [Member] | Maximum [Member] |  |
Interest rate | 5.50% |
First Mortgage Bonds - Series GG [Member] |  |
Due date of debt | Aug. 01, 2026 |
Interest rate | 0.00% |
First Mortgage Bonds - Series HH [Member] |  |
Due date of debt | Aug. 01, 2026 |
First Mortgage Bonds - Series HH [Member] | Minimum [Member] |  |
Interest rate | 4.00% |
First Mortgage Bonds - Series HH [Member] | Maximum [Member] |  |
Interest rate | 5.00% |
First Mortgage Bonds - Series II [Member] |  |
Due date of debt | Aug. 01, 2024 |
Interest rate | 0.00% |
First Mortgage Bonds - Series JJ [Member] |  |
Due date of debt | Aug. 01, 2027 |
First Mortgage Bonds - Series JJ [Member] | Minimum [Member] |  |
Interest rate | 3.40% |
First Mortgage Bonds - Series JJ [Member] | Maximum [Member] |  |
Interest rate | 5.00% |
First Mortgage Bonds - Series KK [Member] |  |
Due date of debt | Aug. 01, 2028 |
Interest rate | 0.00% |
First Mortgage Bonds - Series LL [Member] |  |
Due date of debt | Aug. 01, 2028 |
First Mortgage Bonds - Series LL [Member] | Minimum [Member] |  |
Interest rate | 5.00% |
First Mortgage Bonds - Series LL [Member] | Maximum [Member] |  |
Interest rate | 5.50% |
First Mortgage Bonds - Series MM [Member] |  |
Due date of debt | Aug. 01, 2030 |
Interest rate | 0.00% |
First Mortgage Bonds - Series NN [Member] |  |
Due date of debt | Aug. 01, 2030 |
First Mortgage Bonds - Series NN [Member] | Minimum [Member] |  |
Interest rate | 3.00% |
First Mortgage Bonds - Series NN [Member] | Maximum [Member] |  |
Interest rate | 4.375% |
First Mortgage Bonds - Series OO [Member] |  |
Due date of debt | Aug. 01, 2031 |
Interest rate | 0.00% |
First Mortgage Bonds - Series PP [Member] |  |
Due date of debt | Aug. 01, 2031 |
First Mortgage Bonds - Series PP [Member] | Minimum [Member] |  |
Interest rate | 2.00% |
First Mortgage Bonds - Series PP [Member] | Maximum [Member] |  |
Interest rate | 5.00% |
First Mortgage Bonds - Series QQ [Member] |  |
Due date of debt | Oct. 01, 2023 |
Interest rate | 5.00% |
First Mortgage Bonds - Series RR [Member] |  |
Due date of debt | Oct. 01, 2038 |
Interest rate | 3.80% |
First Mortgage Bonds - Series SS [Member] |  |
Due date of debt | Oct. 01, 2047 |
Interest rate | 4.25% |
First Mortgage Bonds - Series TT [Member] |  |
Due date of debt | Aug. 01, 2032 |
Interest rate | 0.00% |
First Mortgage Bonds - Series UU [Member] |  |
Due date of debt | Aug. 01, 2032 |
First Mortgage Bonds - Series UU [Member] | Minimum [Member] |  |
Interest rate | 3.00% |
First Mortgage Bonds - Series UU [Member] | Maximum [Member] |  |
Interest rate | 3.25% |
First Mortgage Bonds - Series VV [Member] |  |
Due date of debt | Aug. 01, 2033 |
Interest rate | 0.00% |
First Mortgage Bonds - Series WW [Member] |  |
Due date of debt | Aug. 01, 2033 |
First Mortgage Bonds - Series WW [Member] | Minimum [Member] |  |
Interest rate | 3.00% |
First Mortgage Bonds - Series WW [Member] | Maximum [Member] |  |
Interest rate | 5.00% |
First Mortgage Bonds - Series XX [Member] |  |
Due date of debt | Aug. 01, 2047 |
Interest rate | 0.00% |
First Mortgage Bonds - Series YY [Member] |  |
Due date of debt | Aug. 01, 2047 |
First Mortgage Bonds - Series YY [Member] | Minimum [Member] |  |
Interest rate | 3.00% |
First Mortgage Bonds - Series YY [Member] | Maximum [Member] |  |
Interest rate | 5.00% |
First Mortgage Bonds - Series 2018A [Member] |  |
Due date of debt | Aug. 01, 2047 |
Interest rate | 0.00% |
First Mortgage Bonds - Series 2018B [Member] | Minimum [Member] |  |
Interest rate | 3.00% |
First Mortgage Bonds - Series 2018B [Member] | Maximum [Member] |  |
Interest rate | 5.00% |

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