v3.19.1

Leases (Details) - USD ($) $ in Millions | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Capital Leased Assets, Gross |  | $ 715
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment | $ 6,764 | 6,832
Lesse Operating Lease, Lease Not yet Commenced | $ 1 |
Lessee, Finance Lease, Renewal Term | 37 years |
Assets Held under Capital Leases [Member] |  |
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment |  | $ 353

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- Definition Term of lessee's finance lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980 + Details
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