Pension and Other Postretirement Benefits - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 25, 2015 USD ($)
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution to defined benefit plans	$ 80
Expected contributions to plans during the remainder of fiscal year	18
Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution to defined benefit plans	5
Expected contributions to plans during the remainder of fiscal year	$ 5