Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Statement of Financial Position [Abstract]
Common stock, par value (usd per share)	$ 1	$ 1	$ 1
Common stock, shares outstanding	93,210,645	94,704,173	97,787,954
Preferred stock, par value (usd per share)
Preferred stock, shares outstanding	0	0	5,722