Investments (Tables)

6 Months Ended

Jun. 30, 2016

Schedule of Available-for-sale Securities [Line Items]

Marketable Securities

$ in millions	June 30, 2016	December 31, 2015
Available-for-sale investments:
Seed money	173.7	225.9
CLOs	11.5	1.4
Other debt securities	3.3	5.9
Trading investments:
Investments related to deferred compensation plans	168.5	158.8
Seed money	193.1	191.2
Other equity securities	31.4	48.1
UIT-related equity and debt securities	3.8	4.6
Equity method investments	286.0	352.8
Foreign time deposits	15.0	24.7
Other	5.7	5.7
Total investments	892.0	1,019.1

Realized Gains Losses Available-For-Sale Securities

Realized gains and losses recognized in the Condensed Consolidated Statements of Income during the period from investments classified as available-for-sale are as follows:

	For the three months ended June 30, 2016			For the six months ended June 30, 2016
$ in millions	Proceeds from Sales	Gross Realized Gains	Gross Realized Losses	Proceeds from Sales	Gross Realized Gains	Gross Realized Losses
Seed money	0.6	0.1	—	1.8	0.4	—
CLOs	0.8	—	—	1.3	—	—
Other debt securities	1.0	—	—	2.6	—	—
	2.4	0.1	—	5.7	0.4	—

	For the three months ended June 30, 2015			For the six months ended June 30, 2015
$ in millions	Proceeds from Sales	Gross Realized Gains	Gross Realized Losses	Proceeds from Sales	Gross Realized Gains	Gross Realized Losses
Seed money	6.8	0.4	—	15.7	1.0	—
CLOs	1.4	0.1	—	2.3	0.2	—
	8.2	0.5	—	18.0	1.2	—

Gross Unrealized Holding Gains And Losses Recognized In Other Accumulated Comprehensive Income From Available-For-Sale Investments

Gross unrealized holding gains and losses recognized in other accumulated comprehensive income from available-for-sale investments are presented in the table below:

	June 30, 2016					December 31, 2015
$ in millions	Cost	Gross Unrealized Holding Gains	Gross Unrealized Holding Losses		Fair Value	Cost	Gross Unrealized Holding Gains	Gross Unrealized Holding Losses		Fair Value
Seed money	173.9	6.2	(6.4	)	173.7	227.6	7.6	(9.3	)	225.9
CLOs	10.8	1.2	(0.5	)	11.5	1.3	0.1	—		1.4
Other debt securities	3.1	0.2	—		3.3	5.9	—	—		5.9
	187.8	7.6	(6.9	)	188.5	234.8	7.7	(9.3	)	233.2

Breakdown Of Available-For-Sale Investments with Unrealized Losses

At June 30, 2016, 134 seed money funds (December 31, 2015: 192 seed money funds) had incurred gross unrealized holding losses. The following table provides a breakdown of the unrealized losses.

	June 30, 2016			December 31, 2015
$ in millions	Fair Value	Gross Unrealized Losses		Fair Value	Gross Unrealized Losses
Less than 12 months	23.1	(0.3	)	93.0	(3.0	)
12 months or greater	80.3	(6.1	)	65.5	(6.3	)
Total	103.4	(6.4	)	158.5	(9.3	)

Held-to-maturity Securities [Table Text Block]

Available-for-sale debt securities as of June 30, 2016 by maturity, are set out below:

	Available-for-Sale (Fair Value)
Less than one year	1.7
One to five years	1.5
Five to ten years	8.7
Greater than ten years	2.9
Total available-for-sale	14.8