Long-Term Debt (Details) $ in Millions	Jan. 01, 2016 USD ($)
Fixed rate debt securities | Financial guarantee by Exelis Inc. (terminated on Dec 31, 2015)
Guarantor Obligations [Line Items]
Notes Payable	$ 3,226
5.55% notes, due October 1, 2021 (Exelis) | Financial guarantee by Harris Corporation (terminated on Dec 31, 2015)
Guarantor Obligations [Line Items]
Notes Payable	$ 400
Interest rate on fixed rate debt	5.55%
4.25% notes, due October 1, 2016 (Exelis) | Financial guarantee by Harris Corporation (terminated on Dec 31, 2015)
Guarantor Obligations [Line Items]
Notes Payable	$ 250
Interest rate on fixed rate debt	4.25%