| Disclosure Of Long Lived Assets Held For Sale [Text Block] |
| | Assets Held for Sale | | | March 31, 2018 | | | December 31, 2017 | | | | | | | | | | | | | | | | | | | | | | Other | | | | | | | | Other | | | | | | Bonneville | | Assets Held | | | | | | Bonneville | | Assets Held | | | Total | | LMA | | for Sale | | | Total | | LMA | | for Sale | | | (amounts in thousands) | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Land and land improvements | | $ | 47,110 | | $ | 1,110 | | $ | 46,000 | | | $ | 47,110 | | $ | 1,110 | | $ | 46,000 | | Building | | | 1,520 | | | 1,520 | | | - | | | | 1,970 | | | 1,520 | | | 450 | | Leasehold improvements | | | 88 | | | 88 | | | - | | | | 88 | | | 88 | | | - | | Equipment | | | 2,618 | | | 2,618 | | | - | | | | 2,618 | | | 2,618 | | | - | | Net property and equipment | | | 51,336 | | | 5,336 | | | 46,000 | | | | 51,786 | | | 5,336 | | | 46,450 | | Net radio broadcasting licenses | | | 136,014 | | | 136,014 | | | - | | | | 136,014 | | | 136,014 | | | - | | Other intangibles | | | 1,947 | | | 1,947 | | | - | | | | 1,947 | | | 1,947 | | | - | | Goodwill | | | 22,573 | | | 22,573 | | | - | | | | 22,573 | | | 22,573 | | | - | | Total intangibles | | | 160,534 | | | 160,534 | | | - | | | | 160,534 | | | 160,534 | | | - | | Net assets held for sale | | $ | 211,870 | | $ | 165,870 | | $ | 46,000 | | | $ | 212,320 | | $ | 165,870 | | $ | 46,450 |
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