Long-Term Debt and Revolving Credit Arrangements - Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt Disclosure [Abstract]
Contractual interest coupon	$ 109	$ 110	$ 220	$ 215
Amortization of debt discount and issuance costs	3	2	10	5
Total interest expense from long-term debt	$ 112	$ 112	$ 230	$ 220

Amount of amortization expense attributable to debt discount (premium) and debt issuance costs.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/exampleRef
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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Balance Type:	debit
Period Type:	duration