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Commitments and Contingencies - Carnegie Mellon University Settlement (Details) - USD ($)
$ in Millions
12 Months Ended
Jan. 28, 2017
Jan. 30, 2016
Settlement Agreement and Patent License    
Loss Contingencies [Line Items]    
Litigation settlement, amount $ 750.0  
CMU Litigation    
Loss Contingencies [Line Items]    
Litigation settlement, amount $ 6.2  
CMU Litigation | Cost of Goods Sold for Past Use    
Loss Contingencies [Line Items]    
Litigation settlement, amount   $ 81.3
CMU Litigation | Mutual Release of Claims and Covenant Not to Sue Provisions | Operating Expenses    
Loss Contingencies [Line Items]    
Litigation settlement, amount   654.7
CMU Litigation | Future License Settlement | Cost of Goods Sold for Past Use    
Loss Contingencies [Line Items]    
Litigation settlement, amount   $ 14.0