Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Jul. 31, 2012	Jan. 31, 2012
Trade accounts receivable, allowance for doubtful accounts	$ 4,319	$ 4,432
Property, plant, and equipment, accumulated depreciation	286,826	280,053
Intangible assets, accumulated amortization	$ 179,699	$ 172,182
Common stock, no par value	$ 0	$ 0
Common stock, shares authorized	300,000	300,000
Common stock, shares issued	110,261	109,346
Common stock, shares outstanding	110,261	109,346