Debt Securities - Credit Quality Indictors for HTM Debt Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total municipal bonds held-to-maturity	$ 3,348,698	$ 3,502,411
Municipal Bonds
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total municipal bonds held-to-maturity	1,630,264	1,650,000
Investment Grade | S&P: AAA | Moody's: Aaa | Municipal Bonds
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total municipal bonds held-to-maturity	419,314	427,918
Investment Grade | S&P: AA+, AA, AA- | Moody's: Aa1, Aa2, Aa3 | Municipal Bonds
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total municipal bonds held-to-maturity	1,173,331	1,182,894
Investment Grade | S&P: A+, A, A- | Moody's: A1, A2, A3 | Municipal Bonds
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total municipal bonds held-to-maturity	33,984	37,742
Investment Grade | S&P: Not Rated | Moody's: Not Rated | Municipal Bonds
Debt Securities, Held-to-maturity, Credit Quality Indicator [Line Items]
Total municipal bonds held-to-maturity	$ 3,635	$ 1,446