CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Millions	Total	Total Equity	Common Shares and Paid-in Surplus	Retained Earnings	AOCL, After-tax	Total	Non-controlling Interests
Beginning balance at Dec. 31, 2019		$ 3,144.7	$ 596.3	$ 2,672.4	$ (7.2)	$ 3,261.5	$ (116.8)
Increase (Decrease) in Shareholders' Equity
Net income (loss)	$ 663.4	663.4		708.7		708.7	(45.3)
Other comprehensive income (loss), net of tax	1.4	7.3			6.8	6.8	0.5
Net gain (loss) from foreign currency translation from sale of discontinued operations, net of tax - NSM Group	0.0
Comprehensive income (loss)	715.5	670.7		708.7	6.8	715.5	(44.8)
Dividends declared on common shares		(3.2)		(3.2)		(3.2)
Dividends to non-controlling interests		(2.1)					(2.1)
Issuances of common shares		1.5	1.5			1.5
Repurchases and retirements of common shares	(85.1)	(85.2)	(18.5)	(66.7)		(85.2)
BAM member surplus contribution, net of tax		68.9					68.9
Amortization of restricted share awards		16.6	16.6			16.6
Recognition of equity-based compensation expense of subsidiaries		2.4	2.3			2.3	0.1
Net contributions (distributions) and dilution from other non-controlling interests		2.3	(3.0)			(3.0)	5.3
Acquisition of non-controlling interests		1.3					1.3
Ending balance at Dec. 31, 2020		3,817.9	595.2	3,311.2	(0.4)	3,906.0	(88.1)
Increase (Decrease) in Shareholders' Equity
Net income (loss)	(321.9)	(321.9)		(275.4)		(275.4)	(46.5)
Other comprehensive income (loss), net of tax	1.7	2.1			2.1	2.1
Net gain (loss) from foreign currency translation from sale of discontinued operations, net of tax - NSM Group	0.0
Comprehensive income (loss)	(273.3)	(319.8)		(275.4)	2.1	(273.3)	(46.5)
Dividends declared on common shares		(3.1)		(3.1)		(3.1)
Dividends to non-controlling interests		(2.3)					(2.3)
Issuances of common shares		1.9	1.9			1.9
Issuances of shares to non-controlling interests		6.5					6.5
Repurchases and retirements of common shares	(107.5)	(107.5)	(18.9)	(88.6)		(107.5)
BAM member surplus contribution, net of tax		62.2					62.2
Amortization of restricted share awards		14.7	14.7			14.7
Recognition of equity-based compensation expense of subsidiaries		3.5	3.0			3.0	0.5
Net contributions (distributions) and dilution from other non-controlling interests		0.4	(7.0)	13.4		6.4	(6.0)
Acquisition of non-controlling interests		230.3					230.3
Ending balance at Dec. 31, 2021	3,704.7	3,704.7	588.9	2,957.5	1.7	3,548.1	156.6
Increase (Decrease) in Shareholders' Equity
Net income (loss)	712.4	712.4		792.8		792.8	(80.4)
Other comprehensive income (loss), net of tax	(3.8)	(9.0)			(8.1)	(8.1)	(0.9)
Net gain (loss) from foreign currency translation from sale of discontinued operations, net of tax - NSM Group	(2.9)	2.9			2.9	2.9
Comprehensive income (loss)	787.6	706.3		792.8	(5.2)	787.6	(81.3)
Dividends declared on common shares		(3.0)		(3.0)		(3.0)
Dividends to non-controlling interests		(8.0)					(8.0)
Issuances of common shares		3.0	3.0			3.0
Issuances of shares to non-controlling interests		74.6					74.6
Repurchases and retirements of common shares	(615.8)	(615.8)	(90.0)	(525.8)		(615.8)
BAM member surplus contribution, net of tax		81.4					81.4
Amortization of restricted share awards		14.0	14.0			14.0
Recognition of equity-based compensation expense of subsidiaries		9.5	8.6			8.6	0.9
Net contributions (distributions) and dilution from other non-controlling interests		(14.2)	14.1	(9.7)		4.4	(18.6)
Acquisition of non-controlling interests		(17.5)					(17.5)
Ending balance at Dec. 31, 2022	$ 3,935.0	$ 3,935.0	$ 538.6	$ 3,211.8	$ (3.5)	$ 3,746.9	$ 188.1