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Fair Value Measurement (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended				9 Months Ended
	Sep. 30, 2014 transfers	Sep. 30, 2013 transfers	Sep. 30, 2014 Commercial Mortgage Backed Securities [Member] Level 2 [Member]	Dec. 31, 2013 Commercial Mortgage Backed Securities [Member] Level 2 [Member]	Sep. 30, 2014 Minimum [Member] broker
Fair Value Measurement [Line Items]
Percentage of portfolio of unadjusted fair values obtained	99.60%
Percentage of portfolio of specific unadjusted broker quotes obtained	0.40%
Number of knowledgeable outside security brokers consulted to determine fair value					1
Trading securities, fair value disclosure			$ 22.0	$ 21.9
Transfers between Levels 1, 2, and 3 of the fair value hierarchy	0	0

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The amount of the transfers of assets or liabilities into or out of Levels 1, 2, and 3.

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Number of knowledgeable outside security brokers consulted to determine fair value.

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Percentage of specific unadjusted broker quotes obtained

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Percentage of unadjusted fair value obtained

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Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.4)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

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