Variable Interest Entities (Schedule of Aggregate Assets, Liabilities, and Our Exposure to Loss from those VIEs) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Variable Interest Entity [Line Items]
Assets	$ 39,895,540	$ 37,727,460
Total liabilities	34,208,770	32,433,029
Variable Interest Entity Not Primary Beneficiary [Member] | Debt and equity [member]
Variable Interest Entity [Line Items]
Assets	732,072	798,266
Total liabilities	193,397	278,602
Maximum Exposure to Loss	40,130	40,088
Variable Interest Entity Not Primary Beneficiary [Member] | Miscellaneous Investments [Member]
Variable Interest Entity [Line Items]
Assets	400,188	456,286
Total liabilities	191,170	277,924
Maximum Exposure to Loss	40,130	40,088
Variable Interest Entity Not Primary Beneficiary [Member] | Partnership Interest [Member]
Variable Interest Entity [Line Items]
Assets	331,884	341,980
Total liabilities	2,227	678
Maximum Exposure to Loss	$ 0	$ 0