Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2012	Jan. 31, 2011
Trade accounts receivable, allowance for doubtful accounts	$ 4,432	$ 3,941
Common stock, no par value
Common stock, shares authorized	300,000	300,000
Common stock, shares issued	109,346	111,249
Common stock, shares outstanding	109,346	111,249