Advance Payments and Deferred Revenue/Credits (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
advance payments [Line Items]
Customer advances- B787 program	$ 212.1
Customer advances- B737 program	125.6
Total Payment [Member]
advance payments [Line Items]
Customer advances- B737 program		$ 123.0
Total Payment [Member]
advance payments [Line Items]
Customer advances- B737 program		225.0
Production Stabilization [Member]
advance payments [Line Items]
Customer advances- B737 program		70.0
To be repaid in 2021 [Member]
advance payments [Line Items]
Customer advances- B737 program		10.0
Prepayment of shipset deliveries [Member]
advance payments [Line Items]
Customer advances- B737 program	$ 68.5	$ 155.0