Advance Payments and Deferred Revenue/Credits (Details) $ / ship_set in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) $ / ship_set	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Deferred Revenue Arrangement [Line Items]
Increase (Decrease) in Customer Advances	$ (21.0)	$ 120.8	$ (98.3)
Advance payments and deferred revenue/credits summarized
Amortization Of Advances Per Ship Set (dollars per ship set) | $ / ship_set	450
Customer advances- 787 program	$ 212.1
Customer advances- Irkut program	1.2
customer advances- 737 program 2019 MOA	123.0
customer advances- 737 program- 2020 MOA	$ 225.0