Acquisitions (Details 1) (Dimensions [Member], USD $) In Thousands, except Per Share data	3 Months Ended	6 Months Ended
	Jul. 31, 2010	Jul. 31, 2010
Dimensions [Member]
Pro forma financial information of Dimensions
Total net sales	$ 567,470	$ 1,070,439
Net earnings attributable to common shareholders	$ 46,382	$ 60,243
Net earnings per common share attributable to common shareholders:
Basic	$ 0.87	$ 1.14
Diluted	$ 0.87	$ 1.13