Investments in Equity Securities (Details) - USD ($) $ in Thousands |
Mar. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Schedule of Trading Securities and Other Trading Assets [Line Items] | ||
| Investments in equity securities | $ 1,673,580 | $ 1,803,064 |
| Charter (a) | ||
| Schedule of Trading Securities and Other Trading Assets [Line Items] | ||
| Investments in equity securities | 1,667,642 | 1,800,208 |
| Other investments | ||
| Schedule of Trading Securities and Other Trading Assets [Line Items] | ||
| Investments in equity securities | $ 5,938 | $ 2,856 |
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- Definition Equity Securities, Noncurrent No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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