Aircraft Lease Assets (Details) - Unit	Jun. 30, 2019	Dec. 31, 2018
Regional Jet Aircraft
Number owned	13	13
Percentage of net book value	86.00%	81.00%
Turboprop Aircraft
Number owned	2	4
Percentage of net book value	14.00%	18.00%
Engines
Number owned	0	1
Percentage of net book value	0.00%	1.00%