Other Assets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Other Assets [Line Items]
Other assets, net of accumulated amortization	$ 1,826		$ 2,027
Spirit Aerosystems [Member]
Other Assets [Line Items]
Loss Contingency, Receivable		$ 137	137
Sea Launch Receivables [Member]
Other Assets [Line Items]
Other assets, net of accumulated amortization	244		$ 356
Sea Launch Receivables [Member] | S.P. Koroley Rocket And Space Corporation Energia [Member]
Other Assets [Line Items]
Other assets, net of accumulated amortization	111
Sea Launch Receivables [Member] | PO Yuzhnoye Mashinostroitelny Zavod [Member]
Other Assets [Line Items]
Other assets, net of accumulated amortization	89
Sea Launch Receivables [Member] | KB Yuzhnoye [Member]
Other Assets [Line Items]
Other assets, net of accumulated amortization	$ 44