Consolidated Balance Sheets (Unaudited) (Parenthetical) (Unaudited) - $ / shares	Jul. 31, 2015	Jan. 31, 2015	Jul. 31, 2014
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 1	$ 1	$ 1
Common stock, shares authorized (in shares)	100,000,000	100,000,000	100,000,000
Common stock, shares issued (in shares)	67,006,000	66,947,000	65,376,000
Treasury stock, at cost (in shares)	29,447,000	28,897,000	28,897,000