Consolidated Statements of Changes In Shareholders' Equity (Parenthetical) - shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement Of Stockholders Equity [Abstract]
Stock issued during period, shares, Employee Stock Purchase Plans	2,747	3,334
Stock issued during period shares, Director Stock Purchase Plans	714
Stock issued during period, shares, Restricted stock activity	3,996	2,115