Derivatives and Hedging Activities - Derivatives (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Cumulative basis adjustments for fair value hedges
Amortized cost of the Hedged Assets	$ 3,354,388		$ 3,354,388		$ 3,807,239
Hedged Asset, Statement of Financial Position [Extensible Enumeration]	Fair Value		Fair Value		Fair Value
Amortized Cost of Fair Value Hedging Included in the Carrying Amount of the Hedged Assets	$ 19,839		$ 19,839		$ 17,988
Interest rate swap
Notional and estimated fair value amount of derivative positions
Notional Amount	1,630,500		1,630,500		1,500,000
Asset Derivative	0		0		0
Liability Derivative	$ 19,839		$ 19,839		$ 17,988
Remaining Maturity			1 year 4 months 24 days		2 years 1 month 6 days
Pay Rate	4.56%		4.56%		4.63%
Interest rate swap | Interest income on investment securities
Fair value hedge relationships on the income statement
Gain (loss) on fair value hedges recognized in earnings	$ (18,935)	$ 0	$ 7,023	$ 0
AFS debt securities | Interest income on investment securities
Fair value hedge relationships on the income statement
Gain (loss) on fair value hedges recognized in earnings	$ 22,148	$ 0	$ 1,851	$ 0