Investment Securities (Restrictions on Redemption Frequency and Advance Notice Requirements) (Details) (Hedge funds, USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Investment securities
Trading Securities, Other	$ 120.8
Distributions from inactive hedge funds	3.0
Investments entities that calculate net asset value per share redemption request	2.1
Monthly
Investment securities
Trading Securities, Other	5.8
Quarterly
Investment securities
Trading Securities, Other	79.7
Semi-annual
Investment securities
Trading Securities, Other	25.4
Annual
Investment securities
Trading Securities, Other	9.9
30-59 days notice
Investment securities
Trading Securities, Other	29.2
30-59 days notice | Monthly
Investment securities
Trading Securities, Other	0
30-59 days notice | Quarterly
Investment securities
Trading Securities, Other	29.1
30-59 days notice | Semi-annual
Investment securities
Trading Securities, Other	0
30-59 days notice | Annual
Investment securities
Trading Securities, Other	0.1
60-89 days notice
Investment securities
Trading Securities, Other	55.6
60-89 days notice | Monthly
Investment securities
Trading Securities, Other	0
60-89 days notice | Quarterly
Investment securities
Trading Securities, Other	30.2
60-89 days notice | Semi-annual
Investment securities
Trading Securities, Other	25.4
60-89 days notice | Annual
Investment securities
Trading Securities, Other	0
90-119 days notice
Investment securities
Trading Securities, Other	21.4
90-119 days notice | Monthly
Investment securities
Trading Securities, Other	0
90-119 days notice | Quarterly
Investment securities
Trading Securities, Other	11.8
90-119 days notice | Semi-annual
Investment securities
Trading Securities, Other	0
90-119 days notice | Annual
Investment securities
Trading Securities, Other	9.6
120 days notice
Investment securities
Trading Securities, Other	14.6
120 days notice | Monthly
Investment securities
Trading Securities, Other	5.8
120 days notice | Quarterly
Investment securities
Trading Securities, Other	8.6
120 days notice | Semi-annual
Investment securities
Trading Securities, Other	0
120 days notice | Annual
Investment securities
Trading Securities, Other	$ 0.2