Acquisitions and Divestitures - Schedule of Major Classes of Assets and Liabilities Included as Held for Sale (Detail) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 31, 2014
Assets
Total current assets		$ 547
Total assets classified as held for sale		547
Liabilities
Total current liabilities		237
MSI [Member]
Assets
Cash and cash equivalents		61
Billed receivables, net of allowances of $6		77
Contracts in process		70
Inventories		70
Other current assets		10
Total current assets		288
Goodwill		231
Other assets		28
Total assets classified as held for sale		547
Liabilities
Accounts payable, trade		31
Accrued employment costs		22
Accrued expenses		33
Advance payments and billings in excess of costs incurred		55
Other current liabilities		21
Total current liabilities		162
Pension and postretirement benefits		56
Other liabilities		19
Total liabilities classified as held for sale		$ 237