Derivative Instruments (Offsetting Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Offsetting of Financial Assets, Derivatives
Gross Amounts of Recognized Financial Instruments	$ 9,045,718	$ 7,685,050
Gross Amounts Offset in the Consolidated Statement of Financial Position	(9,028,019)	(7,637,939)
Net Amounts Presented in the Consolidated Statement of Financial Position	17,699	47,111
Financial Instruments/Collateral	0	0
Net Amount	17,699	47,111
Securities purchased under agreements to resell
Gross Amounts of Recognized Financial Instruments	25,000	290,000
Gross Amounts Offset in the Consolidated Statement of Financial Position	0	0
Net Amounts Presented in the Consolidated Statement of Financial Position	25,000	290,000
Financial Instruments/Collateral	0	(290,000)
Net Amount	25,000	0
Total Assets
Gross Amounts of Recognized Financial Instruments	9,070,718	7,975,050
Gross Amounts Offset in the Consolidated Statement of Financial Position	(9,028,019)	(7,637,939)
Net Amounts Presented in the Consolidated Statement of Financial Position	42,699	337,111
Financial Instruments/Collateral	0	(290,000)
Net Amount	42,699	47,111
Offsetting of Financial Liabilities, Derivatives
Gross Amounts of Recognized Financial Instruments	21,248,026	18,654,072
Gross Amounts Offset in the Consolidated Statement of Financial Position	(18,596,679)	(16,568,912)
Net Amounts Presented in the Consolidated Statement of Financial Position	2,651,347	2,085,160
Financial Instruments/Collateral	(2,651,347)	(2,085,160)
Net Amount	0	0
Securities sold under agreements to repurchase
Gross Amounts of Recognized Financial Instruments	0	0
Gross Amounts Offset in the Consolidated Statement of Financial Position	0	0
Net Amounts Presented in the Consolidated Statement of Financial Position	0	0
Financial Instruments/Collateral	0	0
Net Amount	0	0
Total Liabilities
Gross Amounts of Recognized Financial Instruments	21,248,026	18,654,072
Gross Amounts Offset in the Consolidated Statement of Financial Position	(18,596,679)	(16,568,912)
Net Amounts Presented in the Consolidated Statement of Financial Position	2,651,347	2,085,160
Financial Instruments/Collateral	(2,651,347)	(2,085,160)
Net Amount	$ 0	$ 0