Income Taxes - Unrecognized Tax Positions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized income tax benefits, January 1	$ 54	$ 56	$ 68
Additions for tax positions of prior years	104	48	6
Reductions for tax positions of prior years	(7)	(26)	(15)
Additions for current year tax positions	179	0	0
Reductions for settlements with taxing authorities	(3)	(26)	(2)
Foreign currency translation and other		2
Foreign currency translation and other	(8)		(1)
Unrecognized income tax benefits, December 31	319	54	56
Expenses (Income) for interest and penalties on tax reserves	(32)	(8)	$ 10
Accrued interest and penalties	48	$ 8
Linde AG
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Additions for current year tax positions	$ 167