Fair Value Disclosures - Carrying Value, Fair Value, and Fair Value Hierarchy (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Financial Liabilities
Total liabilities	$ 401.6	$ 407.0
Carrying Value
Financial Liabilities
Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal)	5.8	5.4
Funds withheld under reinsurance	0.1	0.2
Total liabilities	5.9	5.6
Fair Value
Financial Liabilities
Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal)	6.3	6.2
Funds withheld under reinsurance	0.1	0.2
Total liabilities	6.4	6.4
Fair Value \| Level 1
Financial Liabilities
Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal)	0.0	0.0
Funds withheld under reinsurance	0.1	0.2
Total liabilities	0.1	0.2
Fair Value \| Level 2
Financial Liabilities
Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal)	0.0	0.0
Funds withheld under reinsurance	0.0	0.0
Total liabilities	0.0	0.0
Fair Value \| Level 3
Financial Liabilities
Policy reserves under investment products (Individual and group annuities, subject to discretionary withdrawal)	6.3	6.2
Funds withheld under reinsurance	0.0	0.0
Total liabilities	$ 6.3	$ 6.2

Represents the fair value as of balance sheet date of policy reserves under investment products (individual and group annuities, subject to discretionary withdrawal).

No definition available.

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- References

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- Definition

Amount of funds held as security for payments to be received under reinsurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.13(c))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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- Definition

Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19-26)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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