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/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 210
-Section S99
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-Publisher FASB
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Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	Aug. 01, 2020	Jun. 30, 2020	Jun. 12, 2020	Dec. 31, 2019	Jul. 31, 2010
Debt Instrument [Line Items]
Principal Amount		$ 3,801		$ 3,500
Unamortized Debt Issuance Cost		31		30
Senior Notes [Member] \| 3.375% Senior Notes Due 2030 [Member]
Debt Instrument [Line Items]
Principal Amount		300	$ 300	0
Senior Notes [Member] \| 6 1/2% GO Zone Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Principal Amount		$ 100		$ 100	$ 100
Subsequent Event [Member] \| Senior Notes [Member] \| 6 1/2% GO Zone Senior Notes Due 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed	100.00%
Extinguishment of Debt, Amount	$ 100