Indebtedness - Schedule of Notes Maturity (Details) - Unsecured Senior Notes $ in Millions	Jun. 30, 2019 USD ($)
Debt Instrument [Line Items]
2019	$ 0
2020	0
2021	592
2022	206
2023	950
Thereafter	750
Total	$ 2,498

Face (par) amount of debt instrument at time of issuance.

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
-Section 45
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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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