CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017	Apr. 30, 2016
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts and sales discounts on accounts receivable (in dollars)	$ 82,811	$ 95,686	$ 60,682
Note discount and unamortized issuance costs (in dollars)	$ 52,204	$ 54,365	$ 0
Preferred stock, shares authorized	1,000	1,000	1,000
Preferred stock, shares issued	0	0	0
Preferred stock, shares outstanding	0	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, shares authorized	120,000	120,000	120,000
Common stock, shares issued	49,031	49,016	46,231
Treasury stock, shares	369	376	667