Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Millions	Total	Consolidated Entity Excluding Consolidated Funds Common stock	Consolidated Entity Excluding Consolidated Funds Additional paid-in capital	Consolidated Entity Excluding Consolidated Funds Retained earnings (deficit)	Consolidated Entity Excluding Consolidated Funds Accumulated other comprehensive income (loss)	Consolidated Entity Excluding Consolidated Funds Total shareholders’ equity	Consolidated Entity Excluding Consolidated Funds Non- controlling interests	Consolidated Funds	Consolidated Funds Non- controlling interests
Beginning balance (in shares) at Dec. 31, 2019		85,900,000
Beginning balance at Dec. 31, 2019	$ 114.5	$ 0.1	$ 534.3	$ (452.5)	$ (17.5)	$ 64.4	$ 1.3		$ 48.8
Increase (Decrease) in Stockholders' Equity
Issuance of common stock (in shares)		100,000
Issuance of common stock	$ 0.2		0.2			0.2
Retirement of common stock		(200,000)
Repurchase of common stock (in shares)	(6,412,663)	(6,400,000)
Repurchase of common stock	$ (46.0)		(46.0)			(46.0)
Capital contributions	3.1								3.1
Equity-based compensation	2.5		2.5			2.5
Foreign currency translation adjustment	1.6				1.6	1.6
Amortization related to derivative securities, net of tax	2.3				2.3	2.3
Other changes in non-controlling interests	0.4						0.4
Other movements	1.4		1.4			1.4
Dividends	(10.7)			(10.7)		(10.7)
Net income	315.1			286.7		286.7			28.4
Ending balance (in shares) at Dec. 31, 2020		79,400,000
Ending balance at Dec. 31, 2020	384.4	$ 0.1	492.4	(176.5)	(13.6)	302.4	1.7		80.3
Beginning balance at Dec. 31, 2019								$ 83.9
Increase (Decrease) in redeemable non-controlling interest in consolidated Funds
Capital contributions								151.7
Net consolidation (de-consolidation) of Funds								(236.0)
Net income								0.4
Ending balance at Dec. 31, 2020								0.0
Beginning balance at Dec. 31, 2019	198.4
Increase (Decrease) in total equity and redeemable non-controlling interest in consolidated Funds
Issuance of common stock	0.2
Repurchase of common stock	(46.0)
Capital contributions	154.8
Equity-based compensation	2.5
Foreign currency translation adjustment	1.6
Amortization related to derivative securities, net of tax	2.3
Other changes in non-controlling interests	0.4
Net de-consolidation of Funds	(236.0)
Other movements	1.4
Dividends	(10.7)
Net income	315.5
Ending balance at Dec. 31, 2020	384.4
Increase (Decrease) in Stockholders' Equity
Issuance of common stock (in shares)		1,600,000
Issuance of common stock	$ 2.7		2.7			2.7
Repurchase of common stock (in shares)	0	(35,600,000)
Repurchase of common stock	$ (1,121.7)	$ (0.1)	(465.7)	(655.9)		(1,121.7)
Capital contributions	33.5						3.8		29.7
Equity-based compensation	1.9		1.9			1.9
Foreign currency translation adjustment	0.4				0.4	0.4
Amortization related to derivative securities, net of tax	2.4				2.4	2.4
Withholding tax related to stock option exercise	(31.3)		(31.3)			(31.3)
Other changes in non-controlling interests	(5.5)						(5.5)
Dividends	(2.8)			(2.8)		(2.8)
Net income	896.4			828.4		828.4			68.0
Ending balance (in shares) at Dec. 31, 2021		45,400,000
Ending balance at Dec. 31, 2021	(17.6)	$ 0.0	0.0	(6.8)	(10.8)	(17.6)	0.0		0.0
Increase (Decrease) in redeemable non-controlling interest in consolidated Funds
Capital contributions								0.0
Net consolidation (de-consolidation) of Funds								0.0
Net income	0.0
Ending balance at Dec. 31, 2021								0.0
Increase (Decrease) in total equity and redeemable non-controlling interest in consolidated Funds
Issuance of common stock	2.7
Repurchase of common stock	(1,121.7)
Capital contributions	33.5
Equity-based compensation	1.9
Foreign currency translation adjustment	0.4
Amortization related to derivative securities, net of tax	2.4
Net de-consolidation of Funds	(178.0)								(178.0)
Dividends	(2.8)
Net income	896.4
Ending balance at Dec. 31, 2021	(17.6)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock (in shares)		200,000
Issuance of common stock	$ 0.0		0.0			0.0
Repurchase of common stock (in shares)	(4,147,450)	(4,200,000)
Repurchase of common stock	$ (103.2)	$ 0.0	0.0	(103.2)		(103.2)
Equity-based compensation	2.4		2.4			2.4
Foreign currency translation adjustment	(3.1)				(3.1)	(3.1)
Amortization related to derivative securities, net of tax	3.3				3.3	3.3
Withholding tax related to stock option exercise	(2.3)		(0.9)	(1.4)		(2.3)
Dividends	(1.7)			(1.7)		(1.7)
Net income	100.6			100.6		100.6			0.0
Ending balance (in shares) at Dec. 31, 2022		41,400,000
Ending balance at Dec. 31, 2022	(21.6)	$ 0.0	$ 1.5	$ (12.5)	$ (10.6)	$ (21.6)	$ 0.0		$ 0.0
Ending balance at Dec. 31, 2022								$ 0.0
Increase (Decrease) in total equity and redeemable non-controlling interest in consolidated Funds
Issuance of common stock	0.0
Repurchase of common stock	(103.2)
Equity-based compensation	2.4
Foreign currency translation adjustment	(3.1)
Amortization related to derivative securities, net of tax	3.3
Dividends	(1.7)
Net income	100.6
Ending balance at Dec. 31, 2022	$ (21.6)