Redeemable Noncontrolling Interests (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Redeemable Noncontrolling Interests
Balance at beginning of period	$ 252.1	$ 252.8	$ 251.9
Change in related noncontrolling interest balance	(10.7)	(2.8)	4.9
Changes in redemption value of redeemable noncontrolling interests:
Additions	0.0	7.7	6.8
Redemptions and other	(33.7)	(18.5)	(14.8)
Redemption value adjustments	(39.8)	12.9	4.0
Balance at end of period	$ 167.9	$ 252.1	$ 252.8

Changes in redemption value of redeemable noncontrolling interests [Abstract]

No definition available.

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- Definition

Change in noncontrolling interest balance related to redeemable noncontrolling interests

+ References

No definition available.

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- Definition

Redeemable noncontrolling interests period increase

+ References

No definition available.

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- Definition

Adjustments to the Redemption Value of Redeemable Noncontrolling Interests

+ References

No definition available.

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Decrease in noncontrolling interest (for example, but not limited to, redeeming or purchasing the interests of noncontrolling shareholders, issuance of shares (interests) by the non-wholly owned subsidiary to the parent entity for other than cash, and a buyback of shares (interest) by the non-wholly owned subsidiary from the noncontrolling interests).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569655-111683

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-Publisher FASB
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-Topic 505
-SubTopic 10
-Section S99
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-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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- Definition

The aggregate fair value as of the reporting date of all noncontrolling interests which are redeemable by the (parent) entity (1) at a fixed or determinable price on a fixed or determinable date, (2) at the option of the holder of the noncontrolling interest, or (3) upon occurrence of an event that is not solely within the control of the (parent) entity. This item includes noncontrolling interest holder's ownership (or holders' ownership) regardless of the type of equity interest (common, preferred, other) including all potential organizational (legal) forms of the investee entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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