Shareholders' Equity - Changes in Balances of Component of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 1,962,327	$ 1,661,847
Other comprehensive income (loss) before reclassification	32,928	(11,138)
Amounts reclassified from accumulated other comprehensive income (loss)	2,029	3,707
Other comprehensive income (loss), net of tax amount	34,957	(7,431)
Balance	2,021,227	1,682,599
Securities Available for Sale and Transferred Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(66,885)	(204,670)
Other comprehensive income (loss) before reclassification	27,019	832
Amounts reclassified from accumulated other comprehensive income (loss)	0	0
Other comprehensive income (loss), net of tax amount	27,019	832
Balance	(39,866)	(203,838)
Defined Benefit Pension Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(4,721)	(6,075)
Other comprehensive income (loss) before reclassification	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	19	92
Other comprehensive income (loss), net of tax amount	19	92
Balance	(4,702)	(5,983)
Cash Flow Hedge Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(12,053)	(8,978)
Other comprehensive income (loss) before reclassification	5,909	(11,970)
Amounts reclassified from accumulated other comprehensive income (loss)	2,010	3,615
Other comprehensive income (loss), net of tax amount	7,919	(8,355)
Balance	(4,134)	(17,333)
Accumulated Other Comprehensive (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(83,659)	(219,723)
Balance	$ (48,702)	$ (227,154)