FAIR VALUE MEASUREMENTS - FAIR VALUE ACTIVITY (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Interest sensitive products [Member]
Liabilities:
Purchases	$ (34.0)	$ (30.4)
Sales	14.2	11.4
Issuances	(0.2)	(1.6)
Settlements	16.0	17.8
Purchases, sales, issuances and settlements, net	(4.0)	(2.8)
Corporate securities [Member]
Assets:
Purchases	0.0	0.1
Sales	(15.4)	(20.2)
Issuances	0.0	0.0
Settlements	0.0	0.0
Purchases, sales, issuances and settlements, net	(15.4)	(20.1)
Asset-backed securities [Member]
Assets:
Purchases	21.0	9.9
Sales	(0.1)	(10.7)
Issuances	0.0	0.0
Settlements	0.0	0.0
Purchases, sales, issuances and settlements, net	20.9	(0.8)
Mortgage pass-through securities [Member]
Assets:
Purchases	0.0	0.0
Sales	(0.1)	(0.2)
Issuances	0.0	0.0
Settlements	0.0	0.0
Purchases, sales, issuances and settlements, net	(0.1)	(0.2)
Total fixed maturities, available for sale [Member]
Assets:
Purchases	21.0	10.0
Sales	(15.6)	(31.1)
Issuances	0.0	0.0
Settlements	0.0	0.0
Purchases, sales, issuances and settlements, net	5.4	(21.1)
Equity securities [Member]
Assets:
Purchases	1.1	1.0
Sales	0.0	0.0
Issuances	0.0	0.0
Settlements	0.0	0.0
Purchases, sales, issuances and settlements, net	1.1	1.0
Trading securities [Member]
Assets:
Purchases	0.0
Sales	(1.1)
Issuances	0.0
Settlements	0.0
Purchases, sales, issuances and settlements, net	$ (1.1)	$ 0.0

Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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-Publisher FASB
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-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph c
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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