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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120391452&loc=d3e13212-122682

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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.

+ References

No definition available.

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- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

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Debt (Details) - Repayment - USD ($) $ in Millions				12 Months Ended
Debt (Details) - Repayment - USD ($) $ in Millions	Nov. 01, 2020	Jun. 02, 2019	May 15, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument
Debt, principal amount repaid				$ 500	$ 500	$ 600
Senior Notes [Member] \| 3.90% Senior notes due November 1, 2020 [Member]
Debt Instrument
Debt, principal amount repaid	$ 500
Interest rate (percent)	3.90%			3.90%	3.90%
Senior Notes [Member] \| 5.90% Senior notes due June 2, 2019 [Member]
Debt Instrument
Debt, principal amount repaid		$ 500
Interest rate (percent)		5.90%
Senior Notes [Member] \| 5.80% Senior notes due May 15, 2018 [Member]
Debt Instrument
Debt, principal amount repaid			$ 500
Interest rate (percent)			5.80%