Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data	Jul. 31, 2011	Jan. 31, 2011
Trade accounts receivable, allowance for doubtful accounts	$ 3,570	$ 3,941
Property, plant, and equipment, accumulated depreciation	273,197	257,576
Intangible assets, accumulated amortization	$ 165,658	$ 156,481
Common stock, no par value	$ 0	$ 0
Common stock, shares authorized	300,000	300,000
Common stock, shares issued	109,843	111,249
Common stock, shares outstanding	109,843	111,249
Incentive stock, no par value	$ 0	$ 0
Incentive stock, shares authorized	1,200	1,200
Incentive stock, issued	0	0