CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares shares in Millions	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Common stock, shares authorized	250.0	250.0
Common stock, par value	$ 1	$ 1.00
Common stock, shares issued	104.5	104.3
Common stock, shares outstanding	89.5	91.0