CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 17,495	$ 16,211
Other comprehensive income (loss), net of tax:
Net change in fair value of available for sale debt securities	11,021	(10,414)
Net change in fair value of cash flow hedges	(442)	889
Net change in defined benefit plan obligations	227	360
Total other comprehensive income (loss), net of tax	10,806	(9,165)
Total comprehensive income	$ 28,301	$ 7,046