CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CONSOLIDATED STATEMENTS OF EQUITY
Issuance of restricted shares of common stock	100,005	93,864	109,318
Issuance of shares of common stock upon exercise of stock options	43,053	87,378	43,034
Purchase of shares of common stock	70,686	37,567	34,293
Other comprehensive income, tax	$ 677	$ 717	$ 641