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Other Income (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Other Income [Abstract]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, before Income Tax		$ 11
Gain on remeasurement of Tax Receivable Agreement liability	$ 3	$ 93

X

- Definition

Gain on Remeasurement of Tax Receivable Agreement liability as result of the reduction in the U.S. corporate tax rate to 21%

+ References

No definition available.

+ Details

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X

- Definition

Amount before tax of income (loss) from an individually significant component disposed of or held-for-sale including the portion attributable to the noncontrolling interest. Excludes discontinued operations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3A
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=SL51724579-110230

+ Details

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X

- References

No definition available.

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