CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
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)	8,465	6,015
Distribution of shares of treasury stock for employee stock compensation (in shares)	2,373	1,784
Distribution of shares of treasury stock for directors deferred compensation shares (in shares)	439
Sale of shares of treasury stock (in shares)	3,665	2,648
Purchase of shares of treasury stock (in shares)	272