Consolidated Statements of Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Consolidated Statements of Income
Gains on sale of investments available for sale related to accumulated other comprehensive earnings reclassifications	$ 0	$ 24	$ 0
Provision for income taxes related to income tax expense for reclassification items	$ 0	$ 10	$ 0