CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Cash flows from operations:
Net income	$ 551.5	$ 87.7	$ 581.1	$ 465.3
Charges (credits) to reconcile net income to net cash used for operations:
Net realized and unrealized investment gains	(32.5)	(10.9)	(102.5)	(27.2)
Deferred income benefit			(6.9)	(16.2)
Net income from discontinued operations	15.2	(36.5)	(20.5)	(100.9)
Net gain from sale of discontinued operations, net of tax	(554.3)	(47.9)	(552.7)	(414.5)
Amortization and depreciation			25.9	13.3
Other operating items:
Net change in unearned insurance premiums			36.2	20.1
Net change in deferred acquisition costs			(3.5)	(2.8)
Net change in restricted cash			0.0	5.8
Net change in other assets and liabilities, net			(21.5)	(117.6)
Net cash used for operations - continuing operations			(64.4)	(174.7)
Net cash provided from (used for) operations			92.6	(136.6)
Cash flows from investing activities:
Net change in short-term investments			(612.2)	(82.3)
Sales of fixed maturity and convertible investments			1,631.2	2,009.4
Maturities, calls and paydowns of fixed maturity and convertible investments			178.6	184.4
Sales of common equity securities			407.8	683.0
Distributions, settlements and redemptions of other long-term investments			1.3	10.1
Sales of unconsolidated affiliates and consolidated subsidiaries, net of cash sold			1,131.0	2,657.2
Proceeds paid to non-controlling common shareholders from the sale of consolidated subsidiaries			0.0	(141.6)
Net settlement of investment cash flows and contributions with discontinued operations			167.7	(396.6)
Purchases of other long-term investments			(67.7)	(36.6)
Purchases of common equity securities			(818.6)	(94.7)
Purchases of fixed maturity and convertible investments			(1,189.8)	(3,591.5)
Purchases of unconsolidated affiliates and consolidated subsidiaries, net of cash acquired			0.0	(13.7)
Net change in unsettled investment purchases and sales			(135.6)	(113.7)
Net acquisitions of property and equipment			1.0	(0.9)
Net cash provided from investing activities - continuing operations			694.7	1,072.5
Net cash provided from investing activities			697.7	1,342.2
Cash flows from financing activities:
Draw down of debt and revolving line of credit			361.0	352.5
Repayment of debt and revolving line of credit			(364.6)	(401.8)
Proceeds from issuances of common shares			0.0	3.7
Cash dividends paid to the Company’s common shareholders			(4.6)	(5.4)
Common shares repurchased			(714.6)	(860.9)
Distribution to non-controlling interest shareholders			(0.9)	(0.9)
Contributions from discontinued operations			45.2	42.2
Payments of contingent consideration related to purchases of consolidated subsidiaries			0.0	(7.8)
Capital contributions from BAM members			25.7	28.2
Acquisition of additional subsidiary shares from non-controlling interest			(0.7)	0.0
Other financing activities, net			(9.3)	(5.8)
Net cash used for financing activities - continuing operations			(662.8)	(856.0)
Net cash used for financing activities			(724.7)	(928.7)
Net change in cash during the period - continuing operations			(32.5)	41.8
Cash balances at beginning of period			80.2	72.0	$ 72.0
Add: cash held for sale, excluding discontinued operations, at the beginning of period			0.9	1.2	1.2
Less: cash held for sale, excluding discontinued operations, at the end of period	0.0	3.8	0.0	3.8	0.9
Cash balances at end of period	48.6	111.2	48.6	111.2	80.2
Supplemental cash flows information:
Interest paid			(0.5)	(0.7)
Net income tax refund from national governments			0.0	0.0
Discontinued Operations
Other operating items:
Net cash provided from operations - discontinued operations			157.0	38.1
Cash flows from investing activities:
Net cash provided from investing activities - discontinued operations			3.0	269.7
Cash flows from financing activities:
Net cash used for financing activities - discontinued operations			(61.9)	(72.7)
Cash balances at beginning of period			70.5	245.4	245.4
Cash balances at end of period	$ 0.0	$ 137.3	0.0	137.3	$ 70.5
Supplemental cash flows information:
Net income tax refund from national governments			$ 0.0	$ 18.3