CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 10,940	$ 13,204	$ 24,433	$ 27,477
Other comprehensive income:
Net change in unrealized gains on available-for-sale securities, net of tax	7,130	10,839	26,060	21,738
Net change in unrealized loss on cash flow hedging derivatives, net of tax	52	(1,046)	(702)	(1,877)
Net gain on postretirement plans, net of tax	133	48	266	96
Other comprehensive income	7,315	9,841	25,624	19,957
Comprehensive Income	$ 18,255	$ 23,045	$ 50,057	$ 47,434