The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
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Fair value portion of investments accounted under the equity method.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
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This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Section 45
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
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-Publisher SEC
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 11
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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.

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No definition available.

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Investment Funds Investment Funds (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	21.00%
Investment funds	$ 1,231,700		$ 1,170,040
Income (Loss) from Investment Funds	60,385	$ 50,838
Alternative Investments, Fair Value Disclosure	453,000
Real estate
Schedule of Equity Method Investments [Line Items]
Investment funds	646,102		580,830
Income (Loss) from Investment Funds	33,028
Wholly Owned Properties [Member]
Schedule of Equity Method Investments [Line Items]
Income (Loss) from Investment Funds		51,467
Energy
Schedule of Equity Method Investments [Line Items]
Investment funds	80,900		93,719
Income (Loss) from Investment Funds	7,174	(25,124)
Hedge equity
Schedule of Equity Method Investments [Line Items]
Investment funds	71,371		70,580
Income (Loss) from Investment Funds	791	(3,925)
Other funds
Schedule of Equity Method Investments [Line Items]
Investment funds	433,327		$ 424,911
Income (Loss) from Investment Funds	19,392	$ 28,420
Equity Method Investee [Member]
Schedule of Equity Method Investments [Line Items]
Investment funds	$ 53,100