CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	Common Stock	Retained Earnings	Accumulated Other Comprehensive Loss	Nonredeemable Noncontrolling Interest	Total
Balance at Dec. 31, 2013	$ 1.9	$ 1,496.0	$ (1.1)	$ 13.7	$ 1,510.5
Balance (in shares) at Dec. 31, 2013	188,600,000
Increase (Decrease) in Stockholders' Equity
Net income		107.7		0.7	108.4
Amortization of stock-based compensation		20.1		1.2	21.3
Issuance and forfeitures of restricted stock awards, net (in shares)	2,600,000
Stock option exercises and employee stock purchases		3.7			3.7
Stock option exercises and employee stock purchases (in shares)	500,000
Changes in noncontrolling interests in consolidated investment products				30.0	30.0
Distributions to noncontrolling interests				(0.9)	(0.9)
Change in fair value of redeemable noncontrolling interests		1.6			1.6
Purchase of noncontrolling interests				(0.9)	(0.9)
Repurchase of common stock		(62.2)			(62.2)
Repurchase of common stock (in shares)	(5,300,000)
Dividends paid to JCG shareholders		(43.6)			(43.6)
Balance at Sep. 30, 2014	$ 1.9	1,523.3	(1.1)	43.8	1,567.9
Balance (in shares) at Sep. 30, 2014	186,400,000
Balance at Dec. 31, 2014	$ 1.9	1,540.3	(1.4)	47.3	$ 1,588.1
Balance (in shares) at Dec. 31, 2014	185,200,000				185,153,490
Increase (Decrease) in Stockholders' Equity
Net income		109.2		1.6	$ 110.8
Other comprehensive loss			(10.1)	(7.3)	(17.4)
Amortization of stock-based compensation		26.9		0.8	27.7
Amortization of INTECH appreciation rights				(0.6)	(0.6)
Issuance and forfeitures of restricted stock awards, net (in shares)	2,700,000
Stock option exercises and employee stock purchases		8.2			8.2
Stock option exercises and employee stock purchases (in shares)	1,000,000
Tax impact of stock-based compensation		2.6			2.6
Noncontrolling interest from the acquisition of Kapstream				85.7	85.7
Changes in noncontrolling interests in consolidated investment products				(41.1)	(41.1)
Distributions to noncontrolling interests				(1.0)	(1.0)
Change in fair value of redeemable noncontrolling interests		0.3			0.3
Purchase of noncontrolling interests				(0.4)	(0.4)
Repurchase of common stock		(60.7)			(60.7)
Repurchase of common stock (in shares)	(3,700,000)
Dividends paid to JCG shareholders		(48.6)			(48.6)
Balance at Sep. 30, 2015	$ 1.9	$ 1,578.2	$ (11.5)	$ 85.0	$ 1,653.6
Balance (in shares) at Sep. 30, 2015	185,200,000				185,160,785