Consolidated Balance Sheet (Parentheticals) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par or stated value per share	$ 1	$ 1
Common stock, shares authorized	500,000,000	500,000,000
Common stock, shares, issued	191,935,647	195,403,644
Common stock, shares outstanding	186,614,747	189,405,244