Lease Rental Revenues and Flight Equipment Held for Lease (Details) $ in Thousands	Sep. 30, 2017 USD ($)
Leases [Abstract]
Operating Leases, Future Minimum Payments Receivable, Remainder of Fiscal Year	$ 163,587
Annual future minimum lease rentals receivable
Receivable in Year Two	630,237
Receivable in Year Three	532,026
Receivable in Year Four	424,140
Receivable in Year Five	350,093
Thereafter	830,674
Total	$ 2,930,757