Income Taxes Pre-tax income and the provision for income taxes (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Dec. 31, 2015	Dec. 27, 2014	Dec. 31, 2016	Jun. 27, 2015	Jun. 28, 2014
Provision for income taxes:
Foreign	$ 319.1		$ (1,224.2)	$ 1,053.1	$ 640.2
Total pre-tax income (loss)	8.9		(4,848.3)	260.3	303.6
Current:
Foreign	53.0		26.7	67.4	49.1
United States - federal	58.9		93.0	77.2	42.8
United States - state	3.0		0.7	6.8	9.3
Subtotal	116.5		120.7	149.2	103.4
Deferred:
Foreign	(89.3)		(394.1)	(15.4)	(15.1)
United States - federal	(34.4)		(7.6)	(19.9)	8.4
United States - state	(3.3)		(5.1)	(0.8)	(5.8)
Subtotal	(150.1)		(956.2)	(25.0)	(32.6)
Total (benefit) provision for income taxes	(33.6)	$ 29.4	(835.5)	124.2	70.8
Revenue Commissioners, Ireland [Member]
Provision for income taxes:
Foreign	(310.2)		(3,624.1)	(792.8)	(336.6)
Current:
Foreign	1.6		0.3	(2.2)	2.2
Deferred:
Foreign	$ (23.1)		$ (549.4)	$ 11.1	$ (20.1)