Summary of Significant Accounting Policies and Other Matters - Acquisitions and Investments (Details) - Sempra Solar Holdings, LLC - Con Edison Development $ in Millions	9 Months Ended
Sep. 30, 2019 USD ($)
Business Acquisition [Line Items]
Purchase price adjustment, reclassification, decrease in property, plant and equipment	$ 100
Purchase price adjustment, reclassification, decrease in asset retirement obligations	$ 100

This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to property, plant, and equipment acquired in connection with a business combination for which the initial accounting was incomplete.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 4A
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=116869197&loc=SL65897772-128472

Name:	us-gaap_BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentPropertyPlantAndEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration