Investments Total Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Investments [Abstract]
Equity method investments	$ 1,617,449	$ 1,668,316
Cost method investments	20,898	20,868
Marketable equity securities	2,944	3,516
Total investments	$ 1,641,291	$ 1,692,700

Amount of equity securities categorized neither as held-to-maturity nor as trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount, after adjustment, of cost-method investment. Adjustments include, but are not limited to, dividends received in excess of earnings after date of investment that are considered a return of investment and other than temporary impairments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle).

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