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	$ 21,040	$ 17,273	$ 32,941	$ 34,768
Other comprehensive income (loss), net of tax:
Net change in fair value of available for sale debt securities	(1,808)	6,033	10,998	17,054
Net change in fair value of cash flow hedges	8	(622)	(1,042)	(1,064)
Net change in defined benefit plan obligations	409	226	819	453
Total other comprehensive income (loss), net of tax	(1,391)	5,637	10,775	16,443
Total comprehensive income	$ 19,649	$ 22,910	$ 43,716	$ 51,211