Accumulated Other Comprehensive Income - Schedule of Accumulated Other Comprehensive Income by Component, Net of Tax (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			$ 833.7
Other comprehensive income	$ 6.2	$ 12.4	0.7	$ 12.7
Ending balance	844.5	840.5	844.5	840.5
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(11.6)	18.5	(3.0)	18.1
Other comprehensive income (loss) before reclassifications			(5.7)
Amounts reclassified from accumulated other comprehensive income			(0.2)
Other comprehensive income	2.7	1.8	(5.9)	2.2
Ending balance	(8.9)	20.3	(8.9)	20.3
Unrealized Gains and Losses on Investment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	59.4	44.7	56.3	44.8
Other comprehensive income (loss) before reclassifications			6.6
Amounts reclassified from accumulated other comprehensive income			0.0
Other comprehensive income	3.5	10.6	6.6	10.5
Ending balance	62.9	55.3	62.9	55.3
Pension Liability Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2.2)	(1.5)	(2.2)	(1.5)
Other comprehensive income (loss) before reclassifications			0.0
Amounts reclassified from accumulated other comprehensive income			0.0
Other comprehensive income	0.0	0.0	0.0	0.0
Ending balance	(2.2)	(1.5)	(2.2)	(1.5)
Accumulated Other Comprehensive Income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	45.6	61.7	51.1	61.4
Other comprehensive income (loss) before reclassifications			0.9
Amounts reclassified from accumulated other comprehensive income			(0.2)
Other comprehensive income	6.2	12.4	0.7	12.7
Ending balance	$ 51.8	$ 74.1	$ 51.8	$ 74.1