Goodwill and Other Intangible Assets - Finite-Lived Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite Lived Intangible Asset Disclosures
Weighted average remaining expected life of finite lived intangible assets	16 years
Gross carrying amount	$ 766.7	$ 674.1
Accumulated amortization	198.1	183.6
Net carrying amount	568.6	490.5
Finite lived intangible assets fully amortized during the period	0.5	118.6	$ 5.2
Other Finite Lived Intangible Assets
Amortization expense for intangible assets with finite useful lives	42.5	$ 49.9	$ 48.0
Estimated amortization expense for the next five years
Year 1: Finite lived intangible assets amortization	47.3
Year 2: Finite lived intangible assets amortization	46.9
Year 3: Finite lived intangible assets amortization	46.6
Year 4: Finite lived intangible assets amortization	45.5
Year 5: Finite lived intangible assets amortization	45.0
Brazil mutual fund company
Finite Lived Intangible Asset Disclosures
Gross carrying amount	11.5
Accumulated amortization	3.2
Brazil mutual fund company | Operating expenses
Finite Lived Intangible Asset Disclosures
Other finite lived intangible assets impairment	$ 8.3