v3.23.2
Debt (Details)
3 Months Ended 6 Months Ended
Jan. 06, 2022
Jan. 20, 2021
USD ($)
Jul. 31, 2023
USD ($)
Jul. 31, 2022
USD ($)
Jul. 31, 2023
USD ($)
Jul. 31, 2022
USD ($)
Jan. 31, 2023
USD ($)
Jan. 04, 2021
USD ($)
Apr. 30, 2019
USD ($)
A&R Credit Agreement                  
Line of Credit Facility [Line Items]                  
Minimum interest coverage ratio     3.00   3.00        
Maximum total leverage ratio     5.50   5.50        
Maximum total leverage ratio, stepped down     3.50   3.50        
A&R Credit Agreement | Minimum                  
Line of Credit Facility [Line Items]                  
Commitment fee 0.15%                
A&R Credit Agreement | Maximum                  
Line of Credit Facility [Line Items]                  
Commitment fee 0.25%                
3.00% Senior Notes | Senior Notes                  
Line of Credit Facility [Line Items]                  
Aggregate principal amount   $ 750,000,000              
Stated interest rate   3.00%              
Percentage of original principal amount   40.00%              
Proceeds from issuance of senior notes, net of debt financing costs   $ 738,000,000              
Payment for underwriting commissions   9,400,000              
Payments of financing costs   $ 2,600,000              
Interest expense, amortization of debt issuance costs and accretion of debt discount     $ 6,000,000 $ 6,000,000 $ 12,000,000 $ 12,000,000      
Debt instrument, fair value     646,100,000   646,100,000   $ 645,400,000    
3.00% Senior Notes | Senior Notes | Debt Instrument, Redemption, Period Two                  
Line of Credit Facility [Line Items]                  
Redemption percentage   101.50%              
3.00% Senior Notes | Senior Notes | Debt Instrument, Redemption, Period Three                  
Line of Credit Facility [Line Items]                  
Redemption percentage   100.75%              
3.00% Senior Notes | Senior Notes | Debt Instrument, Redemption, Period Four                  
Line of Credit Facility [Line Items]                  
Redemption percentage   100.00%              
3.00% Senior Notes | Senior Notes | Debt Instrument, Redemption, Period Five                  
Line of Credit Facility [Line Items]                  
Redemption percentage   101.00%              
3.00% Senior Notes | Senior Notes | Plus "Make Whole" Premium | Debt Instrument, Redemption, Period One                  
Line of Credit Facility [Line Items]                  
Redemption percentage   100.00%              
3.00% Senior Notes | Senior Notes | Proceeds From Equity Offering, Provided Principal Amount of Redemptions Does Not Exceed 40% | Debt Instrument, Redemption, Period One                  
Line of Credit Facility [Line Items]                  
Redemption percentage   103.00%              
Revolving Line of Credit                  
Line of Credit Facility [Line Items]                  
Maximum borrowing capacity                 $ 150,000,000
Unused standby letter of credit     $ 0   $ 0   $ 0    
Revolving Line of Credit | A&R Credit Agreement                  
Line of Credit Facility [Line Items]                  
Maximum borrowing capacity               $ 750,000,000  
Incremental borrowing facility               250,000,000  
Letter of Credit                  
Line of Credit Facility [Line Items]                  
Maximum borrowing capacity                 10,000,000
Letter of Credit | A&R Credit Agreement                  
Line of Credit Facility [Line Items]                  
Maximum borrowing capacity               100,000,000  
Swingline                  
Line of Credit Facility [Line Items]                  
Maximum borrowing capacity                 $ 10,000,000
Swingline | A&R Credit Agreement                  
Line of Credit Facility [Line Items]                  
Maximum borrowing capacity               $ 50,000,000  
ABR Loans | A&R Credit Agreement | Federal Funds Rate                  
Line of Credit Facility [Line Items]                  
Margin 0.50%                
ABR Loans | A&R Credit Agreement | Eurodollar Rate                  
Line of Credit Facility [Line Items]                  
Margin 1.00%                
ABR Loans | A&R Credit Agreement | Eurodollar Rate | Minimum                  
Line of Credit Facility [Line Items]                  
Margin (0.25%)                
ABR Loans | A&R Credit Agreement | Eurodollar Rate | Maximum                  
Line of Credit Facility [Line Items]                  
Margin 0.25%