v3.21.1
Debt (Details)
3 Months Ended
Jan. 20, 2021
USD ($)
Jan. 04, 2021
USD ($)
Apr. 30, 2021
USD ($)
Jan. 31, 2021
USD ($)
Apr. 30, 2019
USD ($)
Line of Credit Facility [Line Items]          
Unused standby letter of credit     $ 0 $ 0  
A&R Credit Agreement          
Line of Credit Facility [Line Items]          
Minimum interest coverage ratio     3.00    
Maximum senior secured leverage ratio     3.00    
Maximum total leverage ratio     5.50    
Maximum total leverage ratio, stepped down     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 $ 750,000,000.0        
Stated interest rate 3.00%        
Proceeds from issuance of Senior Notes, net of debt financing costs $ 738,000,000.0        
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     $ 6,000,000.0    
Debt instrument, fair value     $ 743,600,000    
3.00% Senior Notes | Senior Notes | Debt Instrument, Redemption, Period One          
Line of Credit Facility [Line Items]          
Percentage of original principal amount 40.00%        
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         $ 150,000,000.0
Revolving line of credit | A&R Credit Agreement          
Line of Credit Facility [Line Items]          
Maximum borrowing capacity   $ 750,000,000.0      
Incremental borrowing facility   250,000,000.0      
Letter of credit          
Line of Credit Facility [Line Items]          
Maximum borrowing capacity         10,000,000.0
Letter of credit | A&R Credit Agreement          
Line of Credit Facility [Line Items]          
Maximum borrowing capacity   100,000,000.0      
Swingline          
Line of Credit Facility [Line Items]          
Maximum borrowing capacity         $ 10,000,000.0
Swingline | A&R Credit Agreement          
Line of Credit Facility [Line Items]          
Maximum borrowing capacity   $ 50,000,000.0      
Eurodollar Loans | A&R Credit Agreement | LIBOR          
Line of Credit Facility [Line Items]          
Margin   0.00%      
Eurodollar Loans | A&R Credit Agreement | LIBOR | Minimum          
Line of Credit Facility [Line Items]          
Margin   1.50%      
Eurodollar Loans | A&R Credit Agreement | LIBOR | Maximum          
Line of Credit Facility [Line Items]          
Margin   2.00%      
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%