XML 24 R71.htm IDEA: XBRL DOCUMENT v3.19.3
Debt - Convertible Senior Notes Due 2021 (Details)
3 Months Ended 9 Months Ended
Sep. 15, 2015
USD ($)
$ / shares
Oct. 26, 2019
USD ($)
Oct. 27, 2018
USD ($)
Oct. 24, 2015
trading_day
Oct. 26, 2019
USD ($)
Oct. 27, 2018
USD ($)
Jan. 26, 2019
USD ($)
Debt Instrument [Line Items]              
Amortization of debt discount         $ 15,016,000 $ 14,223,000  
0.75% Convertible Senior Notes Due 2021              
Debt Instrument [Line Items]              
Debt, interest rate (in percent)   0.75%     0.75%    
Debt intrument, conversion installments amount $ 1,000            
Debt instrument,conversion ratio 10.3211            
Debt instrument, face amount $ 485,000,000.0 $ 485,000,000     $ 485,000,000   $ 485,000,000
Debt instrument, convertible, conversion price (per share) | $ / shares $ 96.89            
Convertible debt, trading day threshold | trading_day       20      
Convertible debt, consecutive trading day threshold | trading_day       30      
Convertible debt, percentage of stock trigger price threshold       130.00%      
Debt instrument conversion trigger price | $ / shares $ 125.96            
Convertible debt, measurement period for percentage of product sale price of common stock and applicable conversion threshold       98.00%      
Convertible debt, comparable yield   5.50%          
Amortization of debt discount   $ 5,100,000 $ 4,800,000   15,000,000.0 $ 14,200,000  
Convertible Debt   439,743,000     439,743,000   423,199,000
Unamortized discount   40,780,000     40,780,000   55,795,000
Debt issuance cost   4,477,000     4,477,000   6,006,000
Standby Letters of Credit              
Debt Instrument [Line Items]              
Line of credit   $ 0     $ 0   $ 0