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Investments (Details-1) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Available-for-sale securities: |  |  |
Cost basis | $ 2,225 | $ 1,964 |
Gross unrealized gains | 599 | 765 |
Gross unrealized losses | (2) | 0 |
Fair Value | 2,822 | 2,729 |
Equity method investments: |  |  |
Equity method investments | 70,650 | 68,872 |
Other Investments | 159 | 159 |
Total investments | 73,631 | 71,760 |
Results of Investment Liquidation [Abstract] |  |  |
Proceeds from sale of investments | 19 | 38 | $ 39
Gain (loss) on sale of investments | 10 | 21 | 2
ATC [Member] |  |  |
Equity method investments: |  |  |
Equity method investments | 69,466 | 67,673 |
Other Equity Method Investments [Member] |  |  |
Equity method investments: |  |  |
Equity method investments | 1,184 | 1,199 |
MGE [Member] |  |  |
Available-for-sale securities: |  |  |
Cost basis | 480 | 489 |
Gross unrealized gains | 40 | 240 |
Gross unrealized losses | (2) | 0 |
Fair Value | 518 | 729 |
Equity method investments: |  |  |
Equity method investments | 69,466 | 67,673 |
Other Investments | 0 | 0 |
Total investments | 69,984 | 68,402 |
Results of Investment Liquidation [Abstract] |  |  |
Proceeds from sale of investments | 19 | 0 | 16
Gain (loss) on sale of investments | 10 | 0 | $ (3)
MGE [Member] | ATC [Member] |  |  |
Equity method investments: |  |  |
Equity method investments | 69,466 | 67,673 |
MGE [Member] | Other Equity Method Investments [Member] |  |  |
Equity method investments: |  |  |
Equity method investments | $ 0 | $ 0 |

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