Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income	$ (18.8)	$ 91.2
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Amortization and depreciation	5.0	6.7
Share-based payments expense	2.9	4.6
Deferred income tax (benefit) provision, net	(19.8)	5.3
Net realized investment loss (gains)	36.1	(52.5)
Undistributed earnings from alternative investment portfolio	(2.5)	(1.9)
Loss on disposals of long-lived assets, net	0.2	0.0
Change in:
Accrued investment income	2.5	(0.3)
Receivables	217.6	1.8
Deferred acquisition costs	1.1	(0.5)
Ceded unearned premiums	(111.5)	(104.9)
Reserves for losses and loss adjustment expenses	(78.8)	15.2
Unearned premiums	59.2	43.9
Ceded reinsurance payable and funds held	(96.0)	75.8
Income taxes	16.3	3.2
Accrued underwriting expenses and other liabilities	(30.2)	6.7
Other, net	(14.7)	(38.7)
Cash (used in) provided by operating activities	(31.4)	55.6
Cash flows from investing activities:
Sales of fixed maturity investments	594.1	235.5
Maturities and mandatory calls of fixed maturity investments	158.2	65.8
Sales of equity securities	24.8	15.0
Sales of other investments	19.2	22.0
Purchases of fixed maturity investments	(831.1)	(358.9)
Purchases of equity securities	(12.2)	(12.1)
Purchases of other investments	(5.9)	(13.2)
Change in foreign regulatory deposits and voluntary pools	3.9	(0.3)
Change in short-term investments	112.3	38.3
Settlements of foreign currency exchange forward contracts	3.1	3.6
Purchases of fixed assets	(2.3)	(7.3)
Other, net	(2.8)	(20.1)
Cash provided by (used in) investing activities	61.3	(31.7)
Cash flows from financing activities:
Activity under stock incentive plans	0.3	0.3
Payment of cash dividends to common shareholders	(10.7)	(10.8)
Cash used in financing activities	(10.4)	(10.5)
Effect of exchange rate changes on cash	1.4	0.1
Change in cash	20.9	13.5
Cash, beginning of year	137.8	139.2
Cash, end of period	$ 158.7	$ 152.7