Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Data Type:	num:percentItemType
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- Definition

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.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

Represents the aggregate of total long-term debt, including current maturities and short-term debt.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Line-of-Credit Arrangement
-URI http://asc.fasb.org/extlink&oid=6517033

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16(a))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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Period Type:	instant

Debt and Credit Facility - Schedule of Carrying Amounts of Borrowings (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt, Long-term and Short-term, Combined Amount	$ 33,542,000,000		$ 26,346,000,000
Less current portion	2,747,000,000		0
Total long-term debt, net	$ 30,795,000,000		26,346,000,000
Senior Unsecured Notes Due in September 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.85%
Senior Unsecured Notes	$ 999,000,000		998,000,000
2017 Senior Unsecured Notes Due in September 2018 [Member]
Debt Instrument [Line Items]
Senior Unsecured Notes	$ 749,000,000		0
Debt Instrument, Face Amount		$ 750,000,000
2017 Senior Unsecured Notes Due in September 2018 [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.17%
2017 Senior Unsecured Notes Due in March 2019 [Member]
Debt Instrument [Line Items]
Senior Unsecured Notes	$ 748,000,000		0
2017 Senior Unsecured Notes Due in March 2019 [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.22%
Senior Unsecured Notes Due in April 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.05%
Senior Unsecured Notes	$ 499,000,000		499,000,000
Term Loan Due May 2019 [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	$ 0		311,000,000
2017 Senior Unsecured Notes Due in September 2019 with Fixed Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.85%	1.85%
Senior Unsecured Notes	$ 997,000,000		0
Debt Instrument, Face Amount		$ 1,000,000,000.0
2017 Senior Unsecured Notes Due in September 2019 with Floating Rate [Member]
Debt Instrument [Line Items]
Senior Unsecured Notes	$ 499,000,000		0
Debt Instrument, Face Amount		$ 500,000,000
2017 Senior Unsecured Notes Due in September 2019 with Floating Rate [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.25%
Senior Unsecured Notes Due In February 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.35%
Senior Unsecured Notes	$ 499,000,000		498,000,000
Senior Unsecured Notes Due in September 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.55%
Senior Unsecured Notes	$ 1,994,000,000		1,991,000,000
Term Loan Due October 2020 [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	$ 998,000,000		0
Senior Unsecured Notes Due April 2021 Member
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.50%
Senior Unsecured Notes	$ 995,000,000		994,000,000
Senior Unsecured Notes Due December 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.40%
Senior Unsecured Notes	$ 1,246,000,000		1,245,000,000
Senior Unsecured Notes Due in March 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.95%
Senior Unsecured Notes	$ 497,000,000		497,000,000
Senior Unsecured Notes Due in September 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.25%
Senior Unsecured Notes	$ 996,000,000		995,000,000
Term Loan Due October 2022 [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	$ 2,497,000,000		0
Senior Unsecured Notes Due in September 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.50%
Senior Unsecured Notes	$ 745,000,000		744,000,000
Senior Unsecured Notes Due in April 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.70%
Senior Unsecured Notes	$ 1,742,000,000		1,741,000,000
Senior Unsecured Notes Due in February 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.50%
Senior Unsecured Notes	$ 1,744,000,000		1,743,000,000
Senior Unsecured Notes Due in March 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.65%
Senior Unsecured Notes	$ 2,729,000,000		2,726,000,000
Senior Unsecured Notes Due in March 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.95%
Senior Unsecured Notes	$ 1,244,000,000		1,243,000,000
Senior Unsecured Notes Due in September 2035 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.60%
Senior Unsecured Notes	$ 990,000,000		989,000,000
Senior Unsecured Notes Due in September 2036 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.00%
Senior Unsecured Notes	$ 740,000,000		739,000,000
Senior Unsecured Notes Due December 2041 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.65%
Senior Unsecured Notes	$ 995,000,000		995,000,000
Senior Unsecured Notes Due in April 2044 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.80%
Senior Unsecured Notes	$ 1,733,000,000		1,732,000,000
Senior Unsecured Notes Due in February 2045 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.50%
Senior Unsecured Notes	$ 1,730,000,000		1,729,000,000
Senior Unsecured Notes Due in March 2046 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.75%
Senior Unsecured Notes	$ 2,215,000,000		2,214,000,000
Senior Unsecured Notes Due in March 2047 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.15%
Senior Unsecured Notes	$ 1,723,000,000		1,723,000,000
Term Loan Due October 2018 [Member]
Debt Instrument [Line Items]
Line of Credit, Current	$ 999,000,000		$ 0