Derivative Instruments (Offsetting Assets and Liabilities) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Derivatives Assets
Gross Amounts of Recognized Financial Instruments	$ 8,298,627	$ 7,685,050
Gross Amounts Offset in the Consolidated Statement of Financial Position	(8,201,896)	(7,637,939)
Net Amounts Presented in the Consolidated Statement of Financial Position	96,731	47,111
Financial Instruments/Collateral	0	0
Net Amount	96,731	47,111
Securities Purchased under Agreements to Resell
Gross Amounts of Recognized Financial Instruments	0	290,000
Gross Amounts Offset in the Consolidated Statement of Financial Position	0	0
Net Amounts Presented in the Consolidated Statement of Financial Position	0	290,000
Financial Instruments/Collateral	0	(290,000)
Net Amount	0	0
Total Assets
Gross Amounts of Recognized Financial Instruments	8,298,627	7,975,050
Gross Amounts Offset in the Consolidated Statement of Financial Position	(8,201,896)	(7,637,939)
Net Amounts Presented in the Consolidated Statement of Financial Position	96,731	337,111
Financial Instruments/Collateral	0	(290,000)
Net Amount	96,731	47,111
Derivatives Liabilities
Gross Amounts of Recognized Financial Instruments	19,766,950	18,654,072
Gross Amounts Offset in the Consolidated Statement of Financial Position	(17,405,225)	(16,568,912)
Net Amounts Presented in the Consolidated Statement of Financial Position	2,361,725	2,085,160
Financial Instruments/Collateral	(2,361,725)	(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	19,766,950	18,654,072
Gross Amounts Offset in the Consolidated Statement of Financial Position	(17,405,225)	(16,568,912)
Net Amounts Presented in the Consolidated Statement of Financial Position	2,361,725	2,085,160
Financial Instruments/Collateral	(2,361,725)	(2,085,160)
Net Amount	$ 0	$ 0