Fair Value Measurements - Schedule of Assets Measured at Fair Value on a Recurring Basis (Details) - Measured on Recurring Basis - USD ($) $ in Millions	Oct. 02, 2016	Jan. 03, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	$ 4.0	$ 3.7
Available-for-sale investment	158.6	142.3
Total assets at fair value	162.6	146.0
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	4.0	3.7
Available-for-sale investment	158.6	142.3
Total assets at fair value	162.6	146.0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0.0	0.0
Available-for-sale investment	0.0	0.0
Total assets at fair value	0.0	0.0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	0.0	0.0
Available-for-sale investment	0.0	0.0
Total assets at fair value	$ 0.0	$ 0.0