Short-Term Borrowings (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) Item	Dec. 31, 2022 USD ($) Item
Short-term Debt [Line Items]
Short-term borrowings	$ 1,154,829	$ 1,871,271
FHLB Borrowings [Member]
Short-term Debt [Line Items]
Short-term borrowings	$ 700,000	$ 1,425,000
FHLB Borrowings [Member] | FHLB Borrowings, 5 Fixed Rate Notes [Member] | Fixed-rate Term Notes [Member]
Short-term Debt [Line Items]
Number of fixed rate short-term borrowings | Item	1	1
Short-term maturity year	2024	2023