Investment Information - Equity method investments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	$ 3,325,543	$ 3,077,611
Credit related funds
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	1,067,549	1,022,334
Private equity
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	602,802	436,042
Real estate
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	444,755	396,395
Lending
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	409,736	376,649
Equity securities
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	360,906	395,090
Infrastructure
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	226,430	230,070
Energy
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	107,842	119,141
Fixed income
Schedule of Equity Method Investments [Line Items]
Investments accounted for using the equity method	$ 105,523	$ 101,890