Investment Securities (Investments In Private Equity Funds Subject to Lock-Up Periods) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Schedule of Trading Securities and Other Trading Assets [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interest	$ 21.4	$ (0.9)	$ 27.7	$ (8.2)
Private equity funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other long-term investments	90.2		90.2
1-3 years | Private equity funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other long-term investments	27.1		27.1
3-5 years | Private equity funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other long-term investments	3.5		3.5
5-10 years | Private equity funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other long-term investments	59.6		59.6
Greater than 10 years | Private equity funds
Schedule of Trading Securities and Other Trading Assets [Line Items]
Other long-term investments	$ 0.0		$ 0.0