Acquisitions and Divestitures, Goodwill and Intangible Assets - Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018	Apr. 03, 2018
Business Acquisition [Line Items]
Goodwill	[1]	$ 19,668	$ 19,594
CSRA
Business Acquisition [Line Items]
Cash and equivalents				$ 45
Accounts receivable				155
Unbilled receivables				420
Other current assets				303
Property, plant and equipment, net				326
Intangible assets, net				2,066
Goodwill				7,931
Other noncurrent assets				369
Total assets				11,615
Account payable				(135)
Customer advances and deposits				(151)
Current capital lease obligation				(51)
Other current liabilities				(434)
Noncurrent capital lease obligation				(207)
Noncurrent deferred tax liability				(356)
Other noncurrent liabilities				(532)
Total liabilities				(1,866)
Net assets acquired				$ 9,749

[1] Goodwill in the Information Technology and Mission Systems reporting units is net of $536 and $1.3 billion of accumulated impairment losses, respectively.