Income Taxes (Narrative) (Details) $ / shares in Units, kr in Millions, $ in Millions			3 Months Ended		6 Months Ended		12 Months Ended		36 Months Ended
	Jun. 29, 2018 USD ($)	Dec. 31, 2017	Jun. 29, 2018 USD ($) $ / shares	Jun. 30, 2017	Jun. 29, 2018 USD ($) $ / shares	Jun. 30, 2017	Dec. 31, 2017 USD ($)	Dec. 21, 2017	Dec. 31, 2012 DKK (kr)	Dec. 10, 2013 DKK (kr)
Income Tax Examination [Line Items]
Effective tax rate from continuing operations			19.30%	13.60%	19.90%	15.40%
Federal statutory income tax rate, percent		21.00%			21.00%			35.00%
Effective income tax rate reconciliation, other reconciling items, amount			$ 9.0		$ 9.0
Effective income tax rate reconciliation, other reconciling items, per diluted share amount | $ / shares			$ 0.01		$ 0.01
Effective income tax rate reconciliation, other reconciling items, percent			6.90%			5.10%
TCJA, transition tax, provisional tax liability							$ 1,200.0
TCJA, transition tax, provisional tax liability, term							8 years
TCJA, income tax benefit							$ 1,200.0
Foreign tax authority
Income Tax Examination [Line Items]
Income tax examination, amount of tax assessments	$ 245.0		$ 245.0		$ 245.0					kr 1,600
Income tax examination, amount of potential additional tax assessments	$ 145.0								kr 924