CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operations:
Net income (loss)	$ 712.4	$ (321.9)	$ 663.4
Adjustments to reconcile net income to net cash provided from (used for) operations:
Net realized and unrealized investment (gains) losses	98.5	(134.2)	(30.8)
Net realized and unrealized investment (gains) losses from investment in MediaAlpha	93.0	380.3	(686.0)
Amortization of restricted share awards	14.0	14.7	16.6
Amortization and depreciation	4.3	21.6	9.6
Deferred income tax expense (benefit)	12.9	34.7	(30.5)
Net (income) loss from discontinued operation, net of tax - NSM Group	(16.4)	22.6	9.5
Other operating items:
Net change in reinsurance recoverables	(87.7)	(15.1)	0.0
Net change in insurance premiums receivable	(127.8)	(179.3)	0.0
Net change in ceded unearned premiums	7.9	103.1	0.0
Net change in loss and loss adjustment expense reserves	401.8	198.7	0.0
Net change in unearned insurance premiums	159.3	198.6	39.1
Net change in deferred acquisition costs and value of in-force business acquired	(21.9)	(41.8)	(5.8)
Net change in reinsurance payable	(173.0)	(104.2)	0.0
Net change in restricted cash	7.7	4.5	0.0
Proceeds from Kudu Participation Contracts sold	137.5	44.4	0.0
Decrease in Debt Securities, Trading, and Equity Securities, FV-NI	(99.8)	(223.4)	(118.3)
Net change in other assets and liabilities	90.4	11.7	34.8
Net cash provided from (used for) operations - continuing operations	326.3	(3.7)	(96.1)
Net cash provided from (used for) operations - NSM Group discontinued operations (Note 21)	38.7	42.3	35.5
Net cash provided from (used for) operations	365.0	38.6	(60.6)
Cash flows from investing activities:
Net change in short-term investments	(455.1)	59.8	60.9
Sales of fixed maturity investments	188.7	286.3	390.0
Maturities, calls and paydowns of fixed maturity investments	198.5	199.0	180.4
Sales of common equity securities and investment in MediaAlpha	0.0	176.8	787.9
Distributions and redemptions of other long-term investments	115.4	106.4	69.9
Release of cash pre-funded/placed in escrow for Ark Transaction	0.0	646.3	(646.3)
Cash pre-funded for ILS funds managed by Elementum	(70.0)	0.0	0.0
Purchases of fixed maturity investments	(585.5)	(1,219.4)	(537.7)
Purchases of common equity securities	(424.5)	(203.4)	(33.8)
Purchases of other long-term investments	(178.8)	(218.0)	(76.8)
Purchases of consolidated subsidiaries, net of cash acquired	(67.9)	10.6	(9.1)
Net other investing activities	(4.4)	3.8	4.1
Net cash provided from (used for) investing activities - continuing operations	108.4	(151.8)	189.5
Net cash provided from (used for) investing activities - NSM Group discontinued operations (Note 21)	7.1	(56.5)	(124.9)
Net cash provided from (used for) investing activities	115.5	(208.3)	64.6
Cash flows from financing activities:
Draw down of debt and revolving lines of credit	213.8	401.7	32.2
Repayment of debt and revolving lines of credit	(56.7)	(120.1)	(1.9)
Cash dividends paid to common shareholders	(3.0)	(3.1)	(3.2)
Issuances of shares to non-controlling interests	74.6	6.5	0.0
Net (contributions to) distributions from discontinued operations	11.6	0.0	(85.0)
Repurchases and retirements of common shares	(615.8)	(107.5)	(85.2)
BAM member surplus contribution	81.4	62.2	68.9
Net contributions from (distributions to) other non-controlling interests	(21.6)	0.7	(2.5)
Fidus Re premium payments	(10.1)	(8.8)	(3.0)
Other financing activities, net	(1.6)	(13.0)	(0.1)
Net cash provided from (used for) financing activities - continuing operations	(327.4)	218.6	(79.8)
Net cash provided from (used for) financing activities - NSM Group discontinued operations (Note 21)	(17.5)	(1.0)	128.8
Net cash provided from (used for) financing activities – continuing operations	(344.9)	217.6	49.0
Net change in cash during the period - continuing operations	107.3	63.1	13.6
Cash balance at beginning of year	147.7	84.6	71.0
Cash balance at end of year	255.0	147.7	84.6
NSM
Adjustments to reconcile net income to net cash provided from (used for) operations:
Net (income) loss from discontinued operation, net of tax - NSM Group	(16.4)	22.6	9.5
Net (gain) loss from sale of discontined operations, net of tax	(886.8)	0.0	0.0
Cash flows from investing activities:
Proceeds from the sale of consolidated subsidiaries, net of cash sold	1,372.5	0.0	0.0
NSM | Held for Sale
Adjustments to reconcile net income to net cash provided from (used for) operations:
Net (income) loss from discontinued operation, net of tax - NSM Group	(16.4)	22.6	9.5
Net (gain) loss from sale of discontined operations, net of tax	(886.8)	0.0	0.0
Other operating items:
Net cash provided from (used for) operations - NSM Group discontinued operations (Note 21)	38.7	42.3	35.5
Cash flows from investing activities:
Net cash provided from (used for) investing activities - NSM Group discontinued operations (Note 21)	7.1	(56.5)	(124.9)
Cash flows from financing activities:
Net cash provided from (used for) financing activities - NSM Group discontinued operations (Note 21)	(17.5)	(1.0)	128.8
Net change in cash during the period - continuing operations	32.3	(15.0)	36.6
Cash balance at beginning of year	111.6	126.6	90.0
Cash balance at end of year	0.0	111.6	126.6
Sirius Group
Adjustments to reconcile net income to net cash provided from (used for) operations:
Net (gain) loss from sale of discontined operations, net of tax	0.0	(18.7)	2.3
Sirius Group | Held for Sale
Adjustments to reconcile net income to net cash provided from (used for) operations:
Net (gain) loss from sale of discontined operations, net of tax	0.0	(18.7)	2.3
Other Operations
Cash flows from investing activities:
Proceeds from the sale of consolidated subsidiaries, net of cash sold	19.5	0.0	0.0
MediaAlpha
Adjustments to reconcile net income to net cash provided from (used for) operations:
Net realized and unrealized investment (gains) losses from investment in MediaAlpha	$ 93.0	$ 380.3	$ (686.0)