Employee Benefit Plans - Narrative (Details) - USD ($)	3 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Contributions expected to plan	$ 0
Other Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Curtailment loss			$ 13,000,000
Discount rate (as a percent)			3.59%	3.71%
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Curtailment loss		$ 4,000,000
Discount rate (as a percent)		3.94%	4.08%
Decrease to pension liabilities		$ 86,000,000
Decrease to other comprehensive loss	$ 86,000,000