Investment Securities (Narrative) (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) Investments_In_Single_Issuer	Dec. 31, 2021 USD ($)
Investment [Line Items]
Percentage decrease requiring a review for impairment	20.00%
Fair value of securities on other-than-temporary impairment watch list	$ 1,300,000,000	$ 13,400,000
Debt Securities, Available-for-sale, Unrealized Loss Position	12,027,745,000	9,047,662,000
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	1,500,632,000	132,929,000
Available for sale securities in loss position at period end, change in unrealized loss	1,400,000,000
Securities pledged as collateral	$ 4,700,000,000	6,400,000,000
Number of investments in a single issuer that exceed 10% of stockholder's equity | Investments_In_Single_Issuer	0
No investment in a single issuer exceeds this percentage of stockholder's equity	10.00%
Asset Pledged as Collateral with Right
Investment [Line Items]
Financial Instruments, Owned, at Fair Value	$ 211,000,000
Visa Class B Shares [Member]
Investment [Line Items]
Equity Securities without Readily Determinable Fair Value, Amount	0
US Treasury and Government [Member]
Investment [Line Items]
U.S. Treasury inflation-protected securities held	373,800,000
Debt Securities, Available-for-sale, Unrealized Loss Position	986,413,000	296,492,000
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	43,430,000	2,241,000
Investment Securities
Investment [Line Items]
Interest Receivable	$ 38,800,000	$ 39,500,000