Goodwill And Intangible Assets (Narrative) (Details) (USD $)	12 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 225,045,000	$ 96,793,000
Capitalized intangible assets	156,400,000	48,100,000	75,300,000
Interest costs capitalized	0	0	0
Weighted average amortization period (in years)	7 years	6 years	6 years
Amortization expense	$ 37,800,000	$ 35,400,000	$ 26,300,000
Capitalized software and development costs
Goodwill And Intangible Assets [Line Items]
Weighted average amortization period (in years)	8 years	6 years	5 years