CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common stock, par value (in usd per share)	$ 1.00	$ 1.00
Common stock, shares authorized (in shares)	100,000,000	25,413,000
Common stock, shares issued (in shares)	25,413,000	25,413,000
Common stock, shares outstanding (in shares)	17,905,000	18,774,000
Treasury stock, shares (in shares)	7,508,000	6,639,000