Business Disposition and Discontinued Operations - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	May 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (Loss) from Ongoing Equity Method Investment in Discontinued Operation after Disposal	$ 28
Discontinued Operations, Held-for-sale or Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Ownership interest retained, percentage		9.70%

Amount of share in income (loss) of the equity method investee after the disposal of the discontinued operation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 4B
-Subparagraph (d)(4)
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721665-107760

Name:	us-gaap_IncomeLossFromOngoingEquityMethodInvestmentInDiscontinuedOperationAfterDisposal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration