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Investment Information - Equity method investments (Details) - USD ($) $ in Thousands | Sep. 30, 2021 | Dec. 31, 2020
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Schedule of Equity Method Investments [Line Items] |  |
Investments accounted for using the equity method | $ 2,741,293 | $ 2,047,889
Credit related funds |  |
Schedule of Equity Method Investments [Line Items] |  |
Investments accounted for using the equity method | 952,794 | 740,060
Equity securities |  |
Schedule of Equity Method Investments [Line Items] |  |
Investments accounted for using the equity method | 414,322 | 343,058
Real estate |  |
Schedule of Equity Method Investments [Line Items] |  |
Investments accounted for using the equity method | 340,510 | 258,518
Lending |  |
Schedule of Equity Method Investments [Line Items] |  |
Investments accounted for using the equity method | 330,368 | 179,629
Private equity |  |
Schedule of Equity Method Investments [Line Items] |  |
Investments accounted for using the equity method | 365,840 | 235,289
Infrastructure |  |
Schedule of Equity Method Investments [Line Items] |  |
Investments accounted for using the equity method | 222,484 | 175,882
Energy |  |
Schedule of Equity Method Investments [Line Items] |  |
Investments accounted for using the equity method | $ 114,975 | $ 115,453

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