Variable Interest Entities (Schedule of Aggregate Assets, Liabilities, and Our Exposure to Loss from those VIEs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Assets	$ 37,196,124	$ 34,049,715
Total liabilities	31,867,653	29,014,756
Variable Interest Entity Not Primary Beneficiary [Member] | Debt and Equity [Member]
Variable Interest Entity [Line Items]
Assets	791,111	926,179
Total liabilities	297,555	440,441
Gain (Loss) on Price Risk Derivatives, Net	14,776	77,053
Variable Interest Entity Not Primary Beneficiary [Member] | Miscellaneous Investments [Member]
Variable Interest Entity [Line Items]
Assets	388,408	540,767
Total liabilities	296,375	439,507
Gain (Loss) on Price Risk Derivatives, Net	14,776	77,053
Variable Interest Entity Not Primary Beneficiary [Member] | Partnership Interests [Member]
Variable Interest Entity [Line Items]
Assets	402,703	385,412
Total liabilities	1,180	934
Gain (Loss) on Price Risk Derivatives, Net	$ 0	$ 0