Income Taxes - Effective Income Tax Rate (Details)	6 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Jun. 27, 2015
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Provision at statutory rate	12.50%	12.50%	12.50%	12.50%
Ireland tax on non-trading differences	(207.40%)	(47.70%)	(0.40%)	(9.90%)
Expenses not deductible for tax purposes/deductions not expensed for book, net	394.00%	63.40%	(0.70%)	14.70%
Goodwill impairment not deductible for tax purposes	0.00%	0.00%	(2.80%)	0.00%
U.S. Operations:
State income taxes, net of federal benefit	38.40%	(1.40%)	0.10%	(1.00%)
Research and development credit	(13.20%)	(0.60%)	(0.00%)	(0.70%)
Other	112.30%	(5.80%)	0.40%	4.80%
Other foreign differences (earnings taxed at other than applicable statutory rate)	(647.20%)	(22.70%)	3.30%	(16.10%)
Intangible impairment differences	(397.60%)	(3.00%)	4.80%	0.00%
Worldwide operations:
Valuation allowance changes	249.30%	17.80%	0.80%	25.70%
Change in unrecognized taxes	82.70%	25.30%	(0.80%)	17.70%
Withholding taxes	0.00%	17.30%	0.00%	0.00%
Effective income tax rate	(376.20%)	57.30%	17.20%	47.70%
United States
Worldwide operations:
Rate Change Impacts	0.00%	5.40%	0.00%	0.00%
Belgium Taxing Authority
Worldwide operations:
Rate Change Impacts	0.00%	(3.20%)	0.00%	0.00%