Credit Facilities and Long-Term Debt (Summary of Debt Outstanding) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Credit Facilities and Long-Term Debt :
Debt issuance costs and unamortized discount	$ (24)	$ (4)
Total debt	2,368	1,274
Less: short-term borrowings and current maturities of long-term debt	260	78
Long-term debt, net	2,108	1,196
3.550% Senior Notes Due 2016
Credit Facilities and Long-Term Debt :
Outstanding balances	0	600
Debt fair value		607
4.875% Senior Notes Due 2021
Credit Facilities and Long-Term Debt :
Outstanding balances	600	600
2.250% Senior Notes Due 2023
Credit Facilities and Long-Term Debt :
Outstanding balances	522	0
Debt fair value	555
3.250% Senior Notes Due 2026
Credit Facilities and Long-Term Debt :
Outstanding balances	500	0
Debt fair value	487
4.375% Senior Notes Due 2046
Credit Facilities and Long-Term Debt :
Outstanding balances	400	0
Debt fair value	397
Commercial paper
Credit Facilities and Long-Term Debt :
Outstanding balances	65	0
Research and development facility agreement
Credit Facilities and Long-Term Debt :
Outstanding balances	38	76
Research and development finance contract
Credit Facilities and Long-Term Debt :
Outstanding balances	110	0
Term loan
Credit Facilities and Long-Term Debt :
Outstanding balances	157	0
Other
Credit Facilities and Long-Term Debt :
Outstanding balances	$ 0	$ 2

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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
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-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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Amount of unamortized debt discount (premium) and debt issuance costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

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

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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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.

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 1
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-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 942
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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