Retirement Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2016	Jul. 04, 2015	Jul. 02, 2016	Jul. 04, 2015
Net periodic benefit cost (credit)
Unrealized gains, pre-tax		$ 98	$ 7	$ 98
Pension Benefits
Net periodic benefit cost (credit)
Service cost	$ 25	29	49	59
Interest cost	85	82	170	163
Expected return on plan assets	(122)	(121)	(245)	(242)
Amortization of net actuarial loss	26	39	52	78
Amortization of prior service cost (credit)	3	4	7	8
Curtailment and other charges		6		6
Net periodic benefit cost (credit)	17	39	33	72
Postretirement Benefits Other Than Pensions
Net periodic benefit cost (credit)
Service cost		1	1	2
Interest cost	4	4	8	8
Amortization of prior service cost (credit)	(5)	(6)	(11)	(12)
Net periodic benefit cost (credit)	$ (1)	$ (1)	$ (2)	$ (2)
Bell
Net periodic benefit cost (credit)
Workforce reduction (as a percent)		12.00%
Increase to discount rate as a result of remeasurement (as a percent)		0.50%
Discount rate (as a percent)		4.75%
Unrealized gains, pre-tax		$ 98