Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	6 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Jun. 27, 2015
Income Statement [Abstract]
Net sales	$ 2,632.2	$ 4,946.2	$ 5,280.6	$ 4,227.1
Cost of sales	1,553.3	2,966.7	3,228.8	2,582.9
Gross profit	1,078.9	1,979.5	2,051.8	1,644.2
Operating expenses
Distribution	47.9	87.0	88.3	67.7
Research and development	88.2	167.7	184.0	187.8
Selling	325.9	598.4	665.0	319.0
Administration	306.8	461.1	452.2	385.3
Impairment charges	215.6	47.5	2,631.0	6.8
Restructuring	26.9	61.0	31.0	5.1
Other operating income	0.0	(41.4)	0.0	0.0
Total operating expenses	1,011.3	1,381.3	4,051.5	971.7
Operating income (loss)	67.6	598.2	(1,999.7)	672.5
Change in financial assets	(57.3)	24.9	2,608.2	(78.5)
Interest expense, net	89.9	168.1	216.6	146.0
Other expense (Income), net	25.2	(10.1)	22.7	334.2
Loss on extinguishment of debt	0.9	135.2	1.1	10.5
Income (loss) before income taxes	8.9	280.1	(4,848.3)	260.3
Income tax expense (benefit)	(33.6)	160.5	(835.5)	124.2
Net income (loss)	$ 42.5	$ 119.6	$ (4,012.8)	$ 136.1
Earnings (loss) per share
Basic (in dollars per share)	$ 0.29	$ 0.84	$ (28.01)	$ 0.97
Diluted (in dollars per share)	$ 0.29	$ 0.84	$ (28.01)	$ 0.97
Weighted-average shares outstanding
Basic (in dollars per share)	145.6	142.3	143.3	139.3
Diluted (in dollars per shares)	146.1	142.6	143.3	139.8
Dividends declared per share	$ 0.25	$ 0.64	$ 0.58	$ 0.4600