Business Acquisitions - Schedule of Purchase Price Allocation, Microsemi (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	May 29, 2018	Mar. 31, 2018
Assets acquired
Goodwill	$ 6,663.9			$ 2,299.0
Microsemi Corporation
Assets acquired
Cash and cash equivalents	340.0	$ 340.0
Accounts receivable	215.6	216.1
Accounts receivable, adjustments	(0.5)
Inventories	576.2	571.5
Inventories, adjustments	4.7
Other current assets	85.2	85.2
Other current assets, adjustments	0.0
Property, plant and equipment	201.5	201.9
Property, plant and equipment, adjustments	(0.4)
Goodwill	4,364.9	4,483.0
Goodwill, adjustment	(118.1)
Purchased intangible assets	5,634.5	5,466.9
Purchased intangible assets, adjustments	167.6
Long-term deferred tax assets	5.9	6.0
Long-term deferred tax assets, adjustments	(0.1)
Other assets	53.3	57.2
Other assets, adjustments	(3.9)
Total assets acquired	11,477.1	11,427.8
Total assets acquired, adjustments	49.3
Liabilities assumed
Accounts payable	(233.8)	(233.8)
Accounts payable, adjustments	0.0
Other current liabilities	(149.3)	(169.4)
Other current liabilities, adjustments	20.1
Long-term line of credit	(2,056.9)	(2,056.9)
Deferred tax liabilities	(565.1)	(604.7)
Deferred tax liabilities, adjustments	39.6
Long-term income tax payable	(177.7)	(87.2)
Long-term income tax payable, adjustments	(90.5)
Other long-term liabilities	(49.8)	(31.3)
Other long-term liabilities, adjustments	(18.5)
Total liabilities assumed	(3,232.6)	(3,183.3)	$ (3,230.0)
Total liabilities assumed, adjustments	(49.3)
Purchase price allocated	8,244.5	$ 8,244.5
Purchase price allocated, adjustments	$ 0.0