Other Financial Data - Investments (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 31, 2017
Net Investment Income [Line Items]
Securities investments					$ 15,000,000
Investments, Fair Value Disclosure	$ 12,000,000		$ 12,000,000
Common stock	10,000,000		10,000,000
Strategic investments, at cost	65,000,000		65,000,000
Strategic investments, at cost					78,000,000
Company-owned life insurance policies	81,000,000		81,000,000		141,000,000
Equity method investments	14,000,000		14,000,000		13,000,000
Long-term investments	172,000,000		172,000,000		247,000,000
Loss on investments			0
Excess cash withdrawal from life insurance investments			60,000,000
Unrealized gain on securities					8,000,000
Gains (losses) on sales of investments and businesses, net	(1,000,000)	$ (1,000,000)	10,000,000	$ 2,000,000
Corporate bonds
Net Investment Income [Line Items]
Securities investments					2,000,000
Securities investments	$ 2,000,000		$ 2,000,000
Common stock
Net Investment Income [Line Items]
Securities investments					$ 13,000,000