CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Stockholders' Equity [Abstract]
Cash dividends declared (in dollars per share)	$ 0.26	$ 0.26
Distribution of shares of treasury stock for directors' compensation (in shares)	7,880	9,532
Distribution of shares of treasury stock for employee stock compensation (in shares)	5,861	7,661
Sale of shares of treasury stock (in shares)	6,101	6,252
Restricted stock awards, forfeited (in shares)	1,139