Stockholders' Equity - Changes in Accumulated Other Comprehensive Income by Component, Net of Tax (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 03, 2016		Dec. 28, 2014	Dec. 29, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at year-end	$ 51.1		$ 61.4
Other comprehensive income (loss) before reclassifications	9.7		(9.5)
Amounts reclassified from accumulated other comprehensive income	(0.1)		(0.8)
Other comprehensive income (loss)	9.6	[1]	(10.3)	$ 26.0
Balance at year-end	60.7		51.1	61.4
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at year-end	(3.0)		18.1
Other comprehensive income (loss) before reclassifications	(19.4)		(20.2)
Amounts reclassified from accumulated other comprehensive income	(0.2)		(0.9)
Other comprehensive income (loss)	(19.6)		(21.1)
Balance at year-end	(22.6)		(3.0)	18.1
Unrealized Gains and Losses on Investment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at year-end	56.3		44.8
Other comprehensive income (loss) before reclassifications	28.6		11.5
Amounts reclassified from accumulated other comprehensive income	0.0		0.0
Other comprehensive income (loss)	28.6		11.5
Balance at year-end	84.9		56.3	44.8
Pension Liability Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at year-end	(2.2)		(1.5)
Other comprehensive income (loss) before reclassifications	0.5		(0.8)
Amounts reclassified from accumulated other comprehensive income	0.1		0.1
Other comprehensive income (loss)	0.6		(0.7)
Balance at year-end	$ (1.6)		$ (2.2)	$ (1.5)

[1] Fiscal year included 53 weeks.