The difference between the fair value and the principal amount of debt not yet amortized.

No definition available.

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Balance Type:	credit
Period Type:	instant

- 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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Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt 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(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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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

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

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-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

+ Details

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Balance Type:	debit
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

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 210.5-02.19,20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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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

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

+ Details

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

+ 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(a)(16))
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-Name Accounting Standards Codification
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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

Long-Term Debt (Schedule Of Long-Term Debt) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Mar. 30, 2016
Debt Instrument [Line Items]
Total Principal	$ 4,211,000,000	$ 4,211,000,000
Increase In Value Of Debt Acquired	26,000,000	26,000,000
Debt Discounts	(40,000,000)	(39,000,000)
Current Portion of Long-Term Debt	0
Long-Term Debt	4,197,000,000	4,198,000,000
6.50% Unsecured Notes [Member] \| Unsecured Notes, Due May 15, 2019 [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 500,000,000	500,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.50%
6.50% Unsecured Notes [Member] \| Unsecured Notes, Due August 15, 2034 [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 750,000,000	750,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.50%
6.50% Unsecured Notes [Member] \| Unsecured Notes, Due February 1, 2038 [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 505,000,000	505,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.50%		6.50%
3.90% Unsecured Notes [Member] \| Unsecured Notes, Due November 15, 2021 [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 600,000,000	600,000,000
Debt Instrument, Interest Rate, Stated Percentage	3.90%
8.125% Unsecured Notes [Member] \| Unsecured Notes, Due September 15, 2030 [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 300,000,000	300,000,000
Debt Instrument, Interest Rate, Stated Percentage	8.125%
7.20% Unsecured Notes [Member] \| Unsecured Notes, Due November 1, 2031 [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 350,000,000	350,000,000
Debt Instrument, Interest Rate, Stated Percentage	7.20%
7.375% Unsecured Notes [Member] \| Unsecured Notes, Due November 1, 2031 [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 500,000,000	500,000,000
Debt Instrument, Interest Rate, Stated Percentage	7.375%
6.625% Unsecured Notes [Member] \| Unsecured Notes, Due August 15, 2037 [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 462,000,000	462,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.625%		6.625%
5.15% Unsecured Notes [Member] \| Unsecured Notes, Due November 15, 2041 [Member]
Debt Instrument [Line Items]
Unsecured Debt	$ 244,000,000	$ 244,000,000
Debt Instrument, Interest Rate, Stated Percentage	5.15%		5.15%