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Investment Securities (Fair Value of Hedge Funds Subject to Restrictions on Redemption Frequency) (Details) $ in Millions | Dec. 31, 2016 USD ($) fund | Dec. 31, 2015 USD ($)
--- | --- | ---
Private equity funds |  |
Investment securities |  |
Number of Investments Held | fund | 23 |
Trading Securities, Other | $ 71.2 |
Hedge funds |  |
Investment securities |  |
Number of Investments Held | fund | 5 |
Trading Securities, Other | $ 59.8 |
Total hedge and private equity funds included in other long-term investments |  |
Investment securities |  |
Trading Securities, Other | 131.0 | $ 127.8
Fair value unfunded commitments | 138.1 | 82.2
Other Long-term Investments Largest Single Investment | 36.5 | 22.7
Private equity funds | Private equity funds |  |
Investment securities |  |
Trading Securities, Other | 71.2 | 90.8
Fair value unfunded commitments | 138.1 | 82.2
Private equity funds | Multi-sector |  |
Investment securities |  |
Trading Securities, Other | 11.4 | 14.8
Fair value unfunded commitments | 2.0 | 2.1
Private equity funds | Energy infrastructure & services |  |
Investment securities |  |
Trading Securities, Other | 14.1 | 20.7
Fair value unfunded commitments | 3.2 | 3.4
Private equity funds | Real estate |  |
Investment securities |  |
Trading Securities, Other | 0.3 | 0.4
Fair value unfunded commitments | 0.1 | 0.1
Private equity funds | Private equity secondaries |  |
Investment securities |  |
Trading Securities, Other | 3.0 | 4.4
Fair value unfunded commitments | 2.1 | 2.1
Private equity funds | Direct Lending [Member] |  |
Investment securities |  |
Trading Securities, Other | 1.8 |
Fair value unfunded commitments | 35.7 |
Private equity funds | Financial Services Sector |  |
Investment securities |  |
Trading Securities, Other | 1.0 |
Fair value unfunded commitments | 5.0 |
Private equity funds | Healthcare |  |
Investment securities |  |
Trading Securities, Other | 3.5 | 3.8
Fair value unfunded commitments | 0.4 | 0.4
Private equity funds | Insurance |  |
Investment securities |  |
Trading Securities, Other | 0.8 | 2.0
Fair value unfunded commitments | 41.3 | 41.3
Private equity funds | Aerospace/Defense/Government |  |
Investment securities |  |
Trading Securities, Other | 19.4 | 19.8
Fair value unfunded commitments | 25.9 | 30.3
Private equity funds | Industrial |  |
Investment securities |  |
Trading Securities, Other | 15.9 | 24.9
Fair value unfunded commitments | 22.4 | 2.5
Hedge funds | Hedge Fund, Long/ Short Equity Banks and Financial [Member] |  |
Investment securities |  |
Trading Securities, Other | 36.5 | 12.8
Fair value unfunded commitments | 0.0 | 0.0
Hedge funds | Hedge funds |  |
Investment securities |  |
Trading Securities, Other | 59.8 | 37.0
Fair value unfunded commitments | 0.0 | 0.0
Hedge funds | Long/short equity REIT |  |
Investment securities |  |
Trading Securities, Other | 19.9 | 20.6
Fair value unfunded commitments | 0.0 | 0.0
Hedge funds | Other hedge funds |  |
Investment securities |  |
Trading Securities, Other | 3.4 | 3.6
Fair value unfunded commitments | $ 0.0 | $ 0.0

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