CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Tax effect on unrealized holding gains (losses) on securities arising during the period	$ (253)	$ 4,300	$ (366)	$ 4,700	$ 1,500
Income tax expense on reclassification adjustment for net gain on sale of securities included in net income	$ 308	$ 725	$ 216	$ 1,033	$ 756