Variable Interest Entities (Schedule of Aggregate Assets, Liabilities, and Our Exposure to Loss from those VIEs) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Assets	$ 36,476,441	$ 34,049,715
Total liabilities	31,351,704	$ 29,014,756
Variable Interest Entity Not Primary Beneficiary [Member] | Debt and equity [member]
Variable Interest Entity [Line Items]
Assets	872,082
Total liabilities	381,054
Gain (Loss) on Price Risk Derivatives, Net	55,902
Variable Interest Entity Not Primary Beneficiary [Member] | Miscellaneous Investments [Member]
Variable Interest Entity [Line Items]
Assets	469,679
Total liabilities	379,966
Gain (Loss) on Price Risk Derivatives, Net	55,902
Variable Interest Entity Not Primary Beneficiary [Member] | Partnership Interest [Member]
Variable Interest Entity [Line Items]
Assets	402,403
Total liabilities	1,088
Gain (Loss) on Price Risk Derivatives, Net	$ 0