Consolidated Statements of Stockholders' Equity (unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Consolidated Statements of Stockholders' Equity (unaudited) [Abstract]
Cash dividends - per share (in dollars per share)	$ 0.22	$ 0.21
Purchase of treasury shares (in shares)	675,535
Net issuance of shares to employee benefit plans and other stock plans, including tax benefit (in shares)	106,674	80,362