Variable Interest Entities (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Variable Interest Entity [Line Items]
VIEs carrying value	$ 5,552,173	$ 5,574,273
Liabilities	4,247,921	4,372,524
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
VIEs carrying value	230,700	234,400
Variable Interest Entity, Primary Beneficiary | PPM RRG
Variable Interest Entity [Line Items]
VIEs carrying value	145,000	139,000
Surplus notes	5,000
Liabilities	$ 145,000	$ 139,000