Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 02, 2016	Sep. 27, 2015	Oct. 02, 2016	Sep. 27, 2015	Jan. 03, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gain (loss) on available-for-sale investments, net of tax	$ 1.3	$ 16.4	$ 8.8	$ 23.0
Temp Holdings Investment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gain (loss) on available-for-sale investments, net of tax	1.3	$ 16.4	8.8	$ 23.0
Cost of available-for-sale investments	$ 20.4		$ 20.4		$ 17.2