Principal Accounting Policies and Basis of Preparation (Correction of Immaterial Error, Impact on Consolidated Balance Sheet) (Details) (USD $) In Millions	Jul. 30, 2011	Jan. 29, 2011	Jul. 31, 2010
Other current assets	$ 91.5	$ 79.2	$ 67.5
Total current assets	2,672.3	2,542.3	2,503.4
Other assets	62.5	59.7	57.2
Deferred tax assets	107.9	86.0	114.9
Total assets	3,247.5	3,089.8	3,063.3
Deferred revenue, current liabilities	135.9	146.0	129.0
Total current liabilities	680.7	711.0	623.2
Deferred revenue, noncurrent liabilities	359.5	353.2	342.7
Total liabilities	1,128.3	1,150.8	1,271.9
Total shareholders' equity	2,119.2	1,939.0	1,791.4
Total liabilities and shareholders' equity	3,247.5	3,089.8	3,063.3
Amounts Previously Reported [Member]
Other current assets			49.4
Total current assets			2,485.3
Other assets			9.8
Deferred tax assets			55.7
Total assets			2,938.6
Deferred revenue, current liabilities			108.8
Total current liabilities			603.0
Deferred revenue, noncurrent liabilities			140.5
Total liabilities			1,049.5
Total shareholders' equity			1,889.1
Total liabilities and shareholders' equity			2,938.6
As Corrected [Member]
Other current assets			67.5
Total current assets			2,503.4
Other assets			57.2
Deferred tax assets			114.9
Total assets			3,063.3
Deferred revenue, current liabilities			129.0
Total current liabilities			623.2
Deferred revenue, noncurrent liabilities			342.7
Total liabilities			1,271.9
Total shareholders' equity			1,791.4
Total liabilities and shareholders' equity			$ 3,063.3