Leases - Maturity of lease liabilities under finance and operating leases (Details) $ in Thousands	Feb. 29, 2020 USD ($)
Finance Leases, ASC842
2021	$ 11,307
2022	4,101
2023	3,946
2024	3,662
2025	3,402
Thereafter	16,660
Total lease payments	43,078
Less: imputed interest	(14,912)
Total finance lease liabilities, ASC842	28,166
Operating Leases, ASC842
2021	662,644
2022	609,984
2023	556,433
2024	493,933
2025	395,822
Thereafter	1,314,774
Total lease payments	4,033,590
Less: imputed interest	(833,082)
Total operating lease liabilities	3,200,508
Minimum sublease rentals	48
Operating and finance leases, ASC842
2021	673,951
2022	614,085
2023	560,379
2024	497,595
2025	399,224
Thereafter	1,331,434
Total lease payments	4,076,668
Less: imputed interest	(847,994)
Total lease liabilities	$ 3,228,674