Commitments (Details 2)	12 Months Ended
	May 31, 2016
Schedule of Aircraft Commitments [Line Items]
2017	12
2018	18
2019	15
2020	15
2021	13
Thereafter	22
Total	95
Boeing 777 Freighter [Member]
Schedule of Aircraft Commitments [Line Items]
2018	2
2019	2
2020	3
2021	3
Thereafter	6
Total	16
Boeing 767 Freighter [Member]
Schedule of Aircraft Commitments [Line Items]
2017	12
2018	16
2019	13
2020	12
2021	10
Thereafter	16
Total	79