CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Common stock, par value (usd per share)	$ 1.25	$ 1.25
Common stock, shares issued	113,473,951	112,888,126	112,499,874	112,405,302
Treasury stock, shares	33,928,928	32,434,274	32,324,911	32,310,937