CONSOLIDATED BALANCE SHEETS (Parentheticals) - $ / shares	Jan. 31, 2016	Jan. 31, 2015
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000.0	2,000,000.0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	750,000,000	750,000,000.0
Common stock, shares outstanding	224,400,000	227,000,000