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INVESTMENTS. (Dividends) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Dividends excluding capital gain distributions [Member] | Available-for-sale sponsored investment portfolios [Member]
Net Investment Income [Line Items]
Dividends	$ 8.2	$ 8.7	$ 18.1

X

- Definition

Amount of dividend income on nonoperating securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(a))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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- Definition

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+ References

No definition available.

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