Goodwill And Intangible Assets (Narrative) (Details) (USD $)	12 Months Ended
	Jan. 31, 2012	Jan. 31, 2011 years	Jan. 31, 2010
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 97,281,000	$ 70,426,000	$ 17,019,000
Capitalized intangible assets	48,200,000	76,500,000	19,100,000
Weighted average amortization period (in years)	6	6	6
Amortization expense	$ 35,400,000	$ 26,300,000	$ 22,200,000
Capitalized Software And Development Costs [Member]
Goodwill And Intangible Assets [Line Items]
Weighted average amortization period (in years)	6	5	6