Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Statement of Stockholders' Equity [Abstract]
Net earnings attributable to noncontrolling interests	$ 1	$ 1
Dividends declared (usd per share)	$ 0.8	$ 0.7

Amount of Net Income (Loss) attributable to redeemable noncontrolling interest.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.19)
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

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