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Investment Securities (Significant Unobservable Inputs) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Assets Measured on Recurring Basis, Transfers out | $ 118.0 | $ 41.8
Standard Poors NR Rating [Member] | Preferred stocks | Par Value [Member] |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Assets, Fair Value Disclosure |  | $ 70.0
Standard Poors NR Rating [Member] | Preferred stocks | Discount Yield |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs |  | 70.0
Standard Poors NR Rating [Member] | Private equity funds |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Average Share Price Used As Unobservable Input | 4 years | 4 years
Volatility Rate | 50.00% | 60.00%
Risk Free Rate | 1.00% | 1.15%
Standard Poors NR Rating [Member] | Private equity funds | Option pricing method [Member] |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs | 0.21 |
Assets, Fair Value Disclosure | $ 9.3 | $ 9.6
Standard Poors NR Rating [Member] | Private equity funds | Discounted cash flows |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs | 0.25 |
Assets, Fair Value Disclosure | $ 22.1 |
Standard Poors NR Rating [Member] | Convertible Preferred Stock | Multiple of EBITDA [Member] |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs | 6.0 | 6.0
Assets, Fair Value Disclosure | $ 3.6 | $ 5.7
Standard Poors NR Rating [Member] | Community Reinvestment Vehicle [Member] | GAAP net equity [Member] |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs | 14.3 | 14.3
Assets, Fair Value Disclosure | $ 14.3 | $ 14.3
Standard Poors NR Rating [Member] | Seller Priority Surplus Note [Member] | Discounted cash flows |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs | 0.096 | 0.13
Assets, Fair Value Disclosure | $ 51.1 | $ 38.0
Standard Poors NR Rating [Member] | Pari Passu Surplus Note [Member] | Discounted cash flows |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs | 0.15 | 0.224
Assets, Fair Value Disclosure | $ 20.8 | $ 13.5
Level 2 |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Assets Measured on Recurring Basis, Transfers out | 0.0 | 0.0
Level 3 Inputs | Fixed maturity investments |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Fair Value, Assets Measured on Recurring Basis, Transfers out | $ 118.0 | $ 40.6
Investment A | Standard Poors NR Rating [Member] | Private equity funds | Recent transaction [Member] |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs | 1.00 | 1.00
Assets, Fair Value Disclosure | $ 21.0 | $ 21.0
Investment B [Member] | Standard Poors NR Rating [Member] | Private equity funds | Recent transaction [Member] |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs | 2.52 | 1.03
Assets, Fair Value Disclosure | $ 3.2 | $ 33.8
Investment C [Member] | Standard Poors NR Rating [Member] | Private equity funds | Recent transaction [Member] |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs |  | 2.52
Assets, Fair Value Disclosure |  | $ 3.0
Investment E | Standard Poors NR Rating [Member] | Convertible Preferred Stock | Recent transaction [Member] |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
Unobservable Inputs | 3.83 | 3.83
Assets, Fair Value Disclosure | $ 27.0 | $ 27.0
Pari Passu Surplus Note [Member] |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
basis points | 2.50% | 2.50%
Seller Priority Surplus Note [Member] |  |
Quantitative information for Level 3 Fair Value Measurements Assets |  |
basis points | 2.50% | 2.50%

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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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- Definition Description of the inputs and valuation technique(s) used to measure fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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