Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 03, 2016	Jun. 28, 2015	Jul. 03, 2016	Jun. 28, 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	$ 15.6	$ 3.5	$ 7.5	$ 6.6
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	15.6	$ 3.5	7.5	$ 6.6
Cost of available-for-sale investments	$ 20.2		$ 20.2		$ 17.2