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Investments Federal Home Loan Bank Carrying Value of Common Stock, Collateral Posted and Advances Received (Details) - USD ($) $ in Millions | Mar. 31, 2018 | Dec. 31, 2017
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Schedule of Federal Home Loan Bank Information |  |
Federal Home Loan Bank Stock | $ 34.1 | $ 34.1
Federal Home Loan Bank, Advances, Branch of FHLB Bank, Amount of Advances | 350.0 | 350.0
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged | 590.1 | 544.8
Fixed Maturity Securities |  |
Schedule of Federal Home Loan Bank Information |  |
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged | 268.5 | 213.3
Mortgage Loans as Collateral |  |
Schedule of Federal Home Loan Bank Information |  |
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged | $ 321.6 | $ 331.5

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- Definition Amount of advances from the Federal Home Loan Bank (FHLB). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822 + Details
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- Definition Amount of the collateral pledged in support of federal home loan bank advances outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823 + Details
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- Definition Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 325 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=75031641&loc=d3e63345-112809 + Details
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