Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (8,992)	$ 35,693
Debt securities available-for-sale:
Net change in unrealized gains (losses) on debt securities available-for-sale	37,025	(10,903)
Related income tax effect	(8,889)	2,785
Net securities gains reclassified into earnings	(40)	0
Related income tax effect	(46)	(59)
Net effect on other comprehensive income (loss) for the period	28,050	(8,177)
Defined benefit plans:
Amortization of net gain and prior service costs	(172)	(101)
Related income tax effect	44	49
Net effect on other comprehensive loss for the period	(128)	(52)
Total other comprehensive income (loss)	27,922	(8,229)
Comprehensive income	$ 18,930	$ 27,464