Leases (Details 2) $ in Millions	May. 31, 2015 USD ($)
Schedule of Future Minimum Operating Lease Payments [Line Items]
2016	$ 2,128
2017	2,241
2018	1,751
2019	1,511
2020	1,265
Thereafter	7,489
Total	16,385
Aircraft and Related Equipment [Member]
Schedule of Future Minimum Operating Lease Payments [Line Items]
2016	461
2017	400
2018	329
2019	273
2020	190
Thereafter	360
Total	2,013
Facilities and Other [Member]
Schedule of Future Minimum Operating Lease Payments [Line Items]
2016	1,667
2017	1,841
2018	1,422
2019	1,238
2020	1,075
Thereafter	7,129
Total	$ 14,372