Share Repurchase Programs and Dividends - Dividends (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
Jan. 31, 2019	Mar. 31, 2019	Mar. 31, 2018
Equity [Abstract]
Cash dividends declared per common share (in dollars per share)	$ 0.1	$ 0.10	$ 0.1
Payments of dividends		$ 46

Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

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