CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 16,211	$ 11,782
Other comprehensive income (loss), net of tax:
Net change in fair value of securities available for sale	(10,414)	401
Net change in fair value of cash flow hedges	889	98
Net change in defined benefit plan obligations	360	213
Total other comprehensive income (loss), net of tax	(9,165)	712
Total comprehensive income	$ 7,046	$ 12,494