Investment Information - Limited partnership interests (Details) - USD ($) $ in Thousands		Sep. 30, 2022	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Maximum Exposure to Loss		$ 3,686,444	$ 3,248,206
Aggregate unfunded commitments		3,100,000	3,000,000
Equity method investments
Schedule of Equity Method Investments [Line Items]
Maximum Exposure to Loss	[1]	3,565,946	3,077,611
Aggregate unfunded commitments		2,800,000	2,600,000
Fair value option
Schedule of Equity Method Investments [Line Items]
Maximum Exposure to Loss	[2]	120,498	170,595
Aggregate unfunded commitments		$ 21,500	$ 18,800

[1] Aggregate unfunded commitments were $2.8 billion at September 30, 2022, compared to $2.6 billion at December 31, 2021.

[2] Aggregate unfunded commitments were $21.5 million at September 30, 2022, compared to $18.8 million at December 31, 2021.