CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 19,935	$ 122,844	$ 166,299
Investments available-for-sale:
Net change in unrealized gains/ (losses) on investments available-for-sale	4,600	34,167	(152,196)
Related income tax (expense)/ benefit	(1,046)	(8,823)	38,762
Net investment losses reclassified into earnings	0	0	345
Related income tax benefit	0	0	(88)
Net effect on other comprehensive income/ (loss)	3,554	25,344	(113,177)
Investments held-to-maturity:
Net change in unrealized loss	1,498	1,726	(14,003)
Related income tax expense/ (benefit)	(368)	(452)	3,567
Net effect on other comprehensive income/ (loss)	1,130	1,274	(10,436)
Defined benefit pension plan:
Net change in unrealized losses	0	10,737	294
Related income tax benefit	0	(2,735)	(93)
Net effect on other comprehensive income/ (loss)	0	8,002	201
Total other comprehensive income/ (loss)	4,684	34,620	(123,412)
Comprehensive income	$ 24,619	$ 157,464	$ 42,887