Nonoperating Income (Expense) (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended			9 Months Ended
	Aug. 31, 2016	Sep. 30, 2016	Apr. 01, 2016	Oct. 02, 2015	Sep. 30, 2016	Oct. 02, 2015
Component of Operating Income [Abstract]
Proceeds from sale of marketable securities			$ 265.0	$ 43.0		$ 43.0
Marketable securities, realized gain				12.0	$ 223.0
Marketable securities, after-tax realized gain				$ 8.0	$ 140.0
Marketable securities, after-tax gain, per diluted share				$ 0.01	$ 0.20
Make-whole premiums to redeem borrowings prior to maturity	$ (188.0)	$ (188.0)			$ (188.1)	0.0
Pretax loss on early extinguishment of borrowings		178.8		$ 0.0	178.8	$ 0.0
Extinguishment of debt, gain (loss), net of tax		$ (112.0)			$ (112.0)
Extinguishment of debt, gain (loss), per share, net of tax		$ (0.16)			$ (0.16)