Consolidated Statements of Equity (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Dividends declared, per common share	$ 0.625	$ 0.5750	$ 0.47
Shares issued for acquisitions	0	77	556
Shares as a result of stock split		187
Treasury Shares
Purchase of treasury shares	0	1,193	17
Additional Paid-in Capital
Income tax on stock option exercise and other shares issued to employees and directors	$ 458	$ 819	$ 1,485
Stock option exercises and other shares issued to employees and directors, shares	196	187	219
Retained Earnings
Dividends declared, per common share	$ 0.625	$ 0.575	$ 0.47