Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Jun. 27, 2015
Accumulated Other Comprehensive Income [Roll Forward]
Balance	$ 10,699.3	$ 5,958.1	$ 10,107.4	$ 8,720.4
OCI before reclassifications	(129.1)	338.1	(64.5)
Amounts reclassified from AOCI	10.3	(3.2)	(2.0)
Other comprehensive income (loss), net of tax	(118.8)	334.9	(66.5)	(36.1)
Balance	10,107.4	6,170.5	5,958.1	10,699.3
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income [Roll Forward]
Balance	103.5	(81.8)	(15.3)	139.6
Other comprehensive income (loss), net of tax	(118.8)	334.9	(66.5)	(36.1)
Balance	(15.3)	253.1	(81.8)	103.5
Fair value of derivative financial instruments, net of tax
Accumulated Other Comprehensive Income [Roll Forward]
Balance	(16.3)	(19.5)	(14.2)
OCI before reclassifications	1.1	7.1	(5.4)
Amounts reclassified from AOCI	1.0	2.6	0.1
Other comprehensive income (loss), net of tax	2.1	9.7	(5.3)
Balance	(14.2)	(9.8)	(19.5)	(16.3)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income [Roll Forward]
Balance	130.9	(67.9)	(4.6)
OCI before reclassifications	(135.5)	328.5	(63.3)
Amounts reclassified from AOCI	0.0	0.0	0.0
Other comprehensive income (loss), net of tax	(135.5)	328.5	(63.3)
Balance	(4.6)	260.6	(67.9)	130.9
Fair value of investment securities, net of tax
Accumulated Other Comprehensive Income [Roll Forward]
Balance	(2.9)	15.1	6.4
OCI before reclassifications	(1.4)	(12.5)	7.4
Amounts reclassified from AOCI	10.7	(1.6)	1.3
Other comprehensive income (loss), net of tax	9.3	(14.1)	8.7
Balance	6.4	1.0	15.1	(2.9)
Post-retirement and pension liability adjustments, net of tax
Accumulated Other Comprehensive Income [Roll Forward]
Balance	(8.2)	(9.5)	(2.9)
OCI before reclassifications	6.7	15.0	(3.2)
Amounts reclassified from AOCI	(1.4)	(4.2)	(3.4)
Other comprehensive income (loss), net of tax	5.3	10.8	(6.6)
Balance	$ (2.9)	$ 1.3	$ (9.5)	$ (8.2)