Current and long-term obligations (Details) - USD ($) $ in Thousands | Sep. 10, 2019 | Jul. 31, 2020 | Aug. 02, 2019 | Apr. 03, 2020 | Jan. 31, 2020 |
Current and long-term obligations | | | | | |
Debt issuance costs, net | | $ (27,941) | | | $ (16,012) |
Current and long-term obligations | | 4,089,001 | | | 2,911,993 |
Current and long-term obligations | | 4,089,001 | | | 2,911,993 |
Repayment of long-term debt | | $ 1,037 | $ 525 | | |
Senior unsecured credit facility | LIBOR loans | | | | | |
Current and long-term obligations | | | | | |
Variable rate basis | | LIBOR | | | |
Spread on variable rate (as a percent) | | 1.015% | | | |
Senior unsecured credit facility | Base-rate loans | | | | | |
Current and long-term obligations | | | | | |
Variable rate basis | | base rate | | | |
Spread on variable rate (as a percent) | | 0.015% | | | |
Senior unsecured credit facility, Revolving Facility | | | | | |
Current and long-term obligations | | | | | |
Current and long-term obligations | | $ 0 | | | |
Current and long-term obligations | | 0 | | | |
Maximum financing under credit agreements | $ 1,250,000 | $ 1,250,000 | | | |
Credit facility term | 5 years | 5 years | | | |
Facility fee rate | | 0.11% | | | |
Borrowing availability under credit facility | | $ 1,250,000 | | | |
Borrowing availability except for amount reserved for commercial paper program | | 1,060,000 | | | |
Senior unsecured credit facility, Revolving Facility | Letters of credit | | | | | |
Current and long-term obligations | | | | | |
Maximum financing under credit agreements | $ 175,000 | 175,000 | | | |
Letters of credit outstanding | | 4,800 | | | |
3.25% Senior Notes due April 15, 2023 | | | | | |
Current and long-term obligations | | | | | |
Current and long-term obligations | | 899,289 | | | 899,163 |
Current and long-term obligations | | 899,289 | | | 899,163 |
Discount on debt issuance | | $ 711 | | | $ 837 |
Stated interest rate (as a percent) | | 3.25% | | | 3.25% |
4.150% Senior Notes due Nov 1, 2025 | | | | | |
Current and long-term obligations | | | | | |
Current and long-term obligations | | $ 499,549 | | | $ 499,511 |
Current and long-term obligations | | 499,549 | | | 499,511 |
Discount on debt issuance | | $ 451 | | | $ 489 |
Stated interest rate (as a percent) | | 4.15% | | | 4.15% |
3.875% Senior Notes due April 15. 2027 | | | | | |
Current and long-term obligations | | | | | |
Current and long-term obligations | | $ 599,685 | | | $ 599,664 |
Current and long-term obligations | | 599,685 | | | 599,664 |
Discount on debt issuance | | $ 315 | | | $ 336 |
Stated interest rate (as a percent) | | 3.875% | | | 3.875% |
4.125% Senior Notes due May 1, 2028 | | | | | |
Current and long-term obligations | | | | | |
Current and long-term obligations | | $ 499,594 | | | $ 499,572 |
Current and long-term obligations | | 499,594 | | | 499,572 |
Discount on debt issuance | | $ 406 | | | $ 428 |
Stated interest rate (as a percent) | | 4.125% | | | 4.125% |
Senior Notes Due 2030 And 2050 [Member] | | | | | |
Current and long-term obligations | | | | | |
Debt issue costs | | | | $ 13,600 | |
3.500% Senior Notes due April 3, 2030 | | | | | |
Current and long-term obligations | | | | | |
Current and long-term obligations | | $ 999,349 | | | |
Current and long-term obligations | | 999,349 | | | |
Discount on debt issuance | | $ 651 | | 700 | |
Amount borrowed | | | | $ 1,000,000 | |
Stated interest rate (as a percent) | | 3.50% | | 3.50% | |
4.125% Senior Notes due April 3, 2050 | | | | | |
Current and long-term obligations | | | | | |
Current and long-term obligations | | $ 495,013 | | | |
Current and long-term obligations | | 495,013 | | | |
Discount on debt issuance | | $ 4,987 | | $ 5,000 | |
Amount borrowed | | | | $ 500,000 | |
Stated interest rate (as a percent) | | 4.125% | | 4.125% | |
Unsecured commercial paper notes | | | | | |
Current and long-term obligations | | | | | |
Current and long-term obligations | | | | | $ 425,200 |
Current and long-term obligations | | | | | 425,200 |
Maximum maturity | | 364 days | | | |
Maximum aggregate borrowing amount | | $ 1,000,000 | | | |
Unsecured commercial paper notes | Wholly-owned subsidiary | | | | | |
Current and long-term obligations | | | | | |
Current and long-term obligations | | 181,000 | | | |
Current and long-term obligations | | 181,000 | | | |
Other | | | | | |
Current and long-term obligations | | | | | |
Current and long-term obligations | | 124,463 | | | 4,895 |
Current and long-term obligations | | 124,463 | | | $ 4,895 |
Letter Of Credit Outside Of Revolving Facility | | | | | |
Current and long-term obligations | | | | | |
Letters of credit outstanding | | $ 53,900 | | | |