Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Apr. 30, 2016	Jan. 31, 2016
Allowance for doubtful accounts receivable, current	$ 3,330	$ 3,826
Property, plant, and equipment, accumulated depreciation	360,156	348,597
Intangible assets, accumulated amortization	$ 229,264	$ 225,818
Common stock, no par value	$ 0	$ 0
Common stock, shares authorized	300,000	300,000
Common stock, shares issued	106,940	114,934
Common stock, shares outstanding	106,940	114,934