Investment Securities (Investments In Private Equity Funds Subject to Lock-Up Periods) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule of Trading Securities and Other Trading Assets [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interest	$ (3.1)	$ (16.0)	$ 24.6	$ (24.2)
Private equity funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other long-term investments	84.6		84.6
1-3 years | Private equity funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other long-term investments	23.5		23.5
3-5 years | Private equity funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other long-term investments	3.8		3.8
5-10 years | Private equity funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other long-term investments	56.3		56.3
Greater than 10 years | Private equity funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other long-term investments	$ 1.0		$ 1.0