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Goodwill and Acquired Client Relationships (Details 2) (USD $) In Millions, unless otherwise specified | 12 Months Ended
--- | ---
Dec. 31, 2012 | Dec. 31, 2011
Total intangible assets |  |
Total, Net book value balance at the beginning of the period | $ 1,321.1 | $ 1,420.6
Total, New investments | 452.6 |
Total, Amortization and Impairment | (200.0) | (97.7)
Total, Foreign currency translation | 11.8 | (1.8)
Total, Net book value balance at the end of the period | 1,585.5 | 1,321.1
Acquired client relationships-mutual fund management contracts |  |
Indefinite-lived |  |
Amortization and Impairment | (102.2) |
Net book value balance at the end of the period | 38.2 |
Impairment of the indefinite-lived intangible assets |  | 9.2
Indefinite-lived intangible assets fair value assumptions, weighted average annual growth rate (as a percent) | 10.00% |
Indefinite-lived intangible assets fair value assumptions, discount rate (as a percent) | 15.00% |
Acquired client relationships |  |
Definite-lived |  |
Gross book value balance at the beginning of the period | 970.5 | 971.1
Accumulated amortization balance at the beginning of the period | (317.0) | (228.5)
Net book value balance at the beginning of the period | 653.5 | 742.6
New investments | 131.1 |
Amortization and impairment | (97.8) | (88.5)
Foreign currency translation | 1.1 | (0.6)
Transfers and other | 38.2 |
Transfers and other | 6.9 |
Transfers and other | 31.3 |
Gross book value balance at the end of the period | 1,109.6 | 970.5
Accumulated amortization balance at the end of the period | (383.5) | (317.0)
Net book value balance at the end of the period | 726.1 | 653.5
Indefinite-lived |  |
Net book value balance at the beginning of the period | 667.6 | 678.0
New investments | 321.5 |
Amortization and Impairment | (102.2) | (9.2)
Foreign currency translation | 10.7 | (1.2)
Transfers and other | (38.2) |
Net book value balance at the end of the period | 859.4 | 667.6
Amortization expenses |  |
Weighted average life | 11 years |
Annual amortization expense for the next five years | $ 100 |
Number of annual periods of expected amortization expense | 5 years |

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