Investments Troubled Debt Restructurings on Financing Receivables (Details) - Commercial Real Estate Portfolio Segment $ in Millions	12 Months Ended
Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Financing Receivable Modifications
Recorded Investment in Mortgage Loan Modifications Due to Foreclosure	$ 5.4	$ 0.0	$ 18.1
Number of Modifications Due to Loan Foreclosure	1	0	1

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524

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Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

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