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Investments Marketable Equity Securities Gains (Losses) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
Marketable Equity Securities Gains (Losses) [Abstract] |  |  |  |
Marketable equity securities gains, net | $ 11,654 | $ 64,570 | $ 27,665 | $ 13,162
Less net gains recognized on marketable equity securities sold | 0 | 36,993 | 263 | 37,316
Unrealized gains (losses) recognized on marketable equity securities held | $ 11,654 | $ 27,577 | $ 27,402 | $ (24,154)

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- Definition Marketable Equity Securities Gains (Losses) [Abstract] + References No definition available. + Details
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- Definition Amount of unrealized and realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI). + References No definition available. + Details
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- Definition Amount of realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI). + References No definition available. + Details
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- Definition Amount of unrealized gain (loss) on investment in marketable security. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(7)(c)) -URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227 + Details
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