Consolidated Balance Sheets (Parenthetical) - $ / shares	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Statement of Financial Position [Abstract]
Common stock, par value (in usd per share)	$ 1	$ 1	$ 1
Common stock, shares authorized	100,000,000	100,000,000	100,000,000
Common stock, shares issued	67,060,000	67,006,000	66,947,000
Treasury stock, shares	30,984,000	30,500,000	28,897,000