Consolidated Statements of Income and Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Tax expense (benefit) from unrealized holding gain (loss) on securities arising during period	$ (2,500)	$ (105)
Tax expense (benefit) from reclassification adjustment from AOCI for sale of securities arising during period	(8)	0
Tax expense (benefit) from unrealized gain (loss) on cash flow hedges arising during period	$ 75	$ 23