Investment Information - Limited partnership interests (Details) - USD ($) $ in Thousands		Dec. 31, 2022	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount		$ 3,904,776	$ 3,248,206
Aggregate commitments		2,900,000	3,000,000
Equity method investments
Schedule of Equity Method Investments [Line Items]
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	[1]	3,774,310	3,077,611
Aggregate commitments		2,600,000	2,600,000
Fair value option
Schedule of Equity Method Investments [Line Items]
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	[2]	130,466	170,595
Aggregate commitments		$ 16,700	$ 18,800

[1] Aggregate unfunded commitments were $2.6 billion at December 31, 2022, consistent with $2.6 billion at December 31, 2021.

[2] Aggregate unfunded commitments were $16.7 million at December 31, 2022, compared to $18.8 million at December 31, 2021.