CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (UNAUDITED) (Parenthetical) - $ / shares	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Statement of Stockholders' Equity [Abstract]
Cash dividends declared (in dollars per share)	$ 0.52	$ 0.52
Distribution of shares of treasury stock for directors' compensation (in shares)	9,532	9,673
Distribution of shares of treasury stock for employee stock compensation (in shares)	7,661	3,303
Distribution of shares of treasury stock for deferred directors' compensation (in shares)	3,740	3,598
Sale of shares of treasury stock (in shares)	9,269	9,814