Investment in Other Companies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) engine
Number of spare engines sold to Aero Engines | engine	14
Aero Engines, LLC.
Payments to acquire interest in joint venture	$ 22,300
Investment ownership (as a percent)	75.00%
Number of spare engines purchased | engine	14
Long-term debt	$ 0
Investment balance in Aero Engines	23,900
Additional interest in Joint venture	1,000
Company's portion of income generated by Aero Engines	$ 600