Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Shareholders’ equity:
Common shares, par value (in dollars per share)	$ 1.25	$ 1.25
Common stock, shares authorized	305,000,000	305,000,000
Common shares, shares issued	176,793,000	176,793,000
Treasury shares, shares	47,703,000	42,444,000