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Investment Securities (Restrictions on Redemption Frequency and Advance Notice Requirements) (Details) - Hedge funds $ in Millions | Sep. 30, 2015 USD ($)
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Schedule of Trading Securities and Other Trading Assets [Line Items] |
Distributions from Inactive Hedge Funds | $ 1.0
Other long-term investments | 55.6
Redemption requests | 22.1
30-59 days notice |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 16.4
Fair Value Investments Entities that Calculate Net Asset Value Per Share Investment Redemption Notice Period60 To89 Days [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 28.1
Fair Value Investments Entities that Calculate Net Asset Value Per Share Investment Redemption Notice Period90 To119 Days [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 2.7
120+ days notice |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 8.4
Monthly |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Monthly | 30-59 days notice |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Monthly | Fair Value Investments Entities that Calculate Net Asset Value Per Share Investment Redemption Notice Period60 To89 Days [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Monthly | Fair Value Investments Entities that Calculate Net Asset Value Per Share Investment Redemption Notice Period90 To119 Days [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Monthly | 120+ days notice |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Quarterly |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 32.9
Quarterly | 30-59 days notice |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 16.4
Quarterly | Fair Value Investments Entities that Calculate Net Asset Value Per Share Investment Redemption Notice Period60 To89 Days [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 8.1
Quarterly | Fair Value Investments Entities that Calculate Net Asset Value Per Share Investment Redemption Notice Period90 To119 Days [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Quarterly | 120+ days notice |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 8.4
Semi-annual |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 20.0
Semi-annual | 30-59 days notice |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Semi-annual | Fair Value Investments Entities that Calculate Net Asset Value Per Share Investment Redemption Notice Period60 To89 Days [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 20.0
Semi-annual | Fair Value Investments Entities that Calculate Net Asset Value Per Share Investment Redemption Notice Period90 To119 Days [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Semi-annual | 120+ days notice |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Annual |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 2.7
Annual | 30-59 days notice |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Annual | Fair Value Investments Entities that Calculate Net Asset Value Per Share Investment Redemption Notice Period60 To89 Days [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 0.0
Annual | Fair Value Investments Entities that Calculate Net Asset Value Per Share Investment Redemption Notice Period90 To119 Days [Member] |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | 2.7
Annual | 120+ days notice |
Schedule of Trading Securities and Other Trading Assets [Line Items] |
Other long-term investments | $ 0.0

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