Revenue Recognition - Narrative (Details) $ in Millions	6 Months Ended
Jun. 30, 2020 USD ($) segment	Dec. 31, 2019 USD ($)
Disaggregation of Revenue [Line Items]
Contract assets	$ 226	$ 368
Contract liabilities	2,121	2,106
Contract liabilities, current	1,693	1,758
Contract liabilities in other long-term liabilities	428	$ 348
Revenue recognized	708
Estimated consideration related to unsatisfied performance obligations	$ 45,000
Long-term supply contracts	20 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Disaggregation of Revenue [Line Items]
Remaining performance obligations, period	5 years
Remaining performance obligation, percentage	50.00%
Revenue from Contract with Customer \| Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	82.00%
Americas, APAC, and EMEA Segments
Disaggregation of Revenue [Line Items]
Number of geographic segments \| segment	3
Engineering \| Revenue from Contract with Customer \| Product Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	18.00%
Minimum
Disaggregation of Revenue [Line Items]
On-site product supply contract	10 years
Minimum \| Merchant
Disaggregation of Revenue [Line Items]
Customer supply agreements	3 years
Minimum \| Packaged Gas
Disaggregation of Revenue [Line Items]
Customer supply agreements	1 year
Maximum
Disaggregation of Revenue [Line Items]
On-site product supply contract	20 years
Maximum \| Merchant
Disaggregation of Revenue [Line Items]
Customer supply agreements	7 years
Maximum \| Packaged Gas
Disaggregation of Revenue [Line Items]
Customer supply agreements	3 years

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Product Supply Contract, Term

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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.

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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

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Period in which remaining performance obligation is expected to be recognized as revenue, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Percentage of remaining performance obligation to total remaining performance obligation not recognized as revenue.

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