Debt Securities - Narrative (Details)	Mar. 31, 2025 USD ($) creditRatingCategory	Dec. 31, 2024 USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Number of credit rating categories, highest | creditRatingCategory	4
Debt securities, available for sale	$ 4,172,312,000	$ 4,245,205,000
Interest receivable, available-for-sale debt securities	8,173,000	8,037,000
ACL on available-for-sale debt securities	0
Debt securities, held to maturity	3,261,575,000	3,294,847,000
Interest receivable, held-to-maturity debt securities	19,131,000	16,538,000
ACL on held-to-maturity debt securities	0	0
Past due
Schedule of Held-to-maturity Securities [Line Items]
Debt securities, available for sale	0	0
Debt securities, held to maturity	$ 0	$ 0