Income Taxes (Narrative) (Details) kr in Millions, $ in Millions			3 Months Ended		12 Months Ended	36 Months Ended
	Mar. 30, 2018 USD ($)	Dec. 22, 2017	Mar. 30, 2018 USD ($)	Mar. 31, 2017	Dec. 31, 2017 USD ($)	Dec. 31, 2012 DKK (kr)	Dec. 10, 2013 DKK (kr)
Income Tax Examination [Line Items]
Effective income tax rate, percent			20.50%	17.30%
Federal statutory income tax rate, percent		21.00%	21.00%		35.00%
Effective income tax rate reconciliation, other reconciling items, percent				(3.20%)
TCJA, transition tax, provisional tax liability					$ 1,200
TCJA, transition tax, provisional tax liability, term					8 years
TCJA, income tax benefit					$ 1,200
Foreign tax authority
Income Tax Examination [Line Items]
Income tax examination, amount of tax assessments	$ 254		$ 254				kr 1,500
Income tax examination, amount of potential additional tax assessments	$ 150					kr 909