Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income	$ (25.2)	$ 120.0
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Amortization and depreciation	14.1	13.8
Share-based payments expense	5.4	8.8
Deferred income tax (benefit) provision, net	(18.4)	3.2
Net realized investment losses (gains)	16.0	(64.5)
Undistributed earnings (loss) from alternative investment portfolio	20.9	(11.4)
Loss on disposals of long-lived assets, net	0.2	0.1
Change in:
Accrued investment income	2.3	0.5
Receivables	31.2	(161.9)
Deferred acquisition costs	5.1	3.5
Ceded unearned premiums	(115.6)	(136.2)
Reserves for losses and loss adjustment expenses	98.5	83.2
Unearned premiums	82.2	103.0
Ceded reinsurance payable and funds held	(140.7)	80.3
Income taxes	25.5	4.4
Accrued underwriting expenses and other liabilities	(70.1)	12.8
Other, net	(34.5)	(64.5)
Cash used in operating activities	(103.1)	(4.9)
Cash flows from investing activities:
Sales of fixed maturity investments	746.0	751.6
Maturities and mandatory calls of fixed maturity investments	255.0	168.8
Sales of equity securities	8.1	32.2
Sales of other investments	94.2	31.1
Purchases of fixed maturity investments	(1,103.6)	(888.5)
Purchases of equity securities	(59.5)	(32.4)
Purchases of other investments	(14.3)	(38.2)
Change in foreign regulatory deposits and voluntary pools	5.0	6.3
Change in short-term investments	212.5	67.7
Settlements of foreign currency exchange forward contracts	7.0	9.9
Proceeds from sale of Trident assets	38.0	0.0
Purchases of fixed assets	(7.6)	(15.7)
Other, net	(5.0)	(22.5)
Cash provided by investing activities	175.8	70.3
Cash flows from financing activities:
Activity under stock incentive plans	1.0	0.9
Payment of cash dividends to common shareholders	(21.3)	(22.7)
Cash used in financing activities	(20.3)	(21.8)
Effect of exchange rate changes on cash	(2.5)	(0.5)
Change in cash	49.9	43.1
Cash, beginning of year	137.8	139.2
Cash, end of period	$ 187.7	$ 182.3