Commitments - Additional Information (Details) $ in Millions		3 Months Ended	12 Months Ended
	Jun. 25, 2020 air-craft	May 31, 2020 USD ($) air-craft	May 31, 2020 USD ($) air-craft
Other Aircraft Commitments Disclosure [Abstract]
Deposit and Progress Payments | $		$ 633	$ 633
B767F [Member]
Other Aircraft Commitments Disclosure [Abstract]
Conditional Aircraft Commitments			1
Number of additional aircraft agreed to purchase options exercised		6	6
Aircraft expected to be delivered, fiscal year			2022
B767F [Member] | Subsequent Event [Member]
Other Aircraft Commitments Disclosure [Abstract]
Number of aircrafts rescheduled delivery, 2021	18
Number of aircrafts rescheduled delivery, 2022	11
Number of aircrafts rescheduled delivery, 2023	13
Number of aircrafts rescheduled delivery, 2024	4
B777F [Member]
Other Aircraft Commitments Disclosure [Abstract]
Conditional Aircraft Commitments			6
B777F Aircraft from 2023 to 2022 [Member]
Other Aircraft Commitments Disclosure [Abstract]
Number of aircrafts rescheduled delivery		2	2
Aircraft expected to be delivered, earliest fiscal year			2022
Aircraft expected to be delivered, latest fiscal year			2023
B767F Aircraft from 2022 to 2023 [Member]
Other Aircraft Commitments Disclosure [Abstract]
Number of aircrafts rescheduled delivery		2	2
Aircraft expected to be delivered, earliest fiscal year			2022
Aircraft expected to be delivered, latest fiscal year			2023
B767F Aircraft from 2020 to 2021 [Member]
Other Aircraft Commitments Disclosure [Abstract]
Number of aircrafts rescheduled delivery		4	4
Aircraft expected to be delivered, earliest fiscal year		2020
Aircraft expected to be delivered, latest fiscal year		2021
B767F Aircraft from 2021 to 2022 [Member]
Other Aircraft Commitments Disclosure [Abstract]
Number of aircrafts rescheduled delivery		2	2
Aircraft expected to be delivered, earliest fiscal year		2021
Aircraft expected to be delivered, latest fiscal year		2022
Cessna Sky Courier 408 Aircraft [Member]
Other Aircraft Commitments Disclosure [Abstract]
Aircraft expected to be delivered, earliest fiscal year		2021
Aircraft expected to be delivered, latest fiscal year		2026
ATR 72-600F [Member]
Other Aircraft Commitments Disclosure [Abstract]
Aircraft expected to be delivered, earliest fiscal year		2021
Aircraft expected to be delivered, latest fiscal year		2026