CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 40,461	$ 35,331	$ 23,828
Other comprehensive income (loss):
Change in net unrealized holding (losses) gains on available-for-sale securities and I/O strips	10,620	(6,383)	417
Deferred income taxes	(3,545)	1,925	(175)
Change in net unamortized unrealized gain on securities available-for-sale that were reclassified to securities held-to-maturity	(65)	(44)	(51)
Deferred income taxes	19	13	22
Reclassification adjustment for (gains) losses realized in income	(661)	(266)	6
Deferred income taxes	195	79	(3)
Change in unrealized gains (losses) on securities and I/O strips, net of deferred income taxes	6,563	(4,676)	216
Change in net pension and other benefit plan liability adjustment	(5,622)	2,196	(923)
Deferred income taxes	1,662	(649)	388
Change in pension and other benefit plan liability, net of deferred income taxes	(3,960)	1,547	(535)
Other comprehensive income (loss)	2,603	(3,129)	(319)
Total comprehensive income	$ 43,064	$ 32,202	$ 23,509