Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017	[1]
Investments:
Fixed maturities available-for-sale, at fair value (cost: 2018 - $3,496.5; 2017 - $3,320.6)	$ 3,456.2	$ 3,343.4
Equity securities, at fair value (cost: 2018 - $358.6; 2017 - $338.2)	486.5	487.4
Other investments (cost: 2018 - $477.8; 2017 - $534.1)	487.5	543.6
Short-term investments, at fair value (cost: 2018 - $434.5; 2017 - $368.5)	434.5	368.5
Total investments	4,864.7	4,742.9
Cash	118.5	176.6
Accrued investment income	26.3	23.5
Premiums receivable	708.9	598.6
Reinsurance recoverables	2,208.2	2,093.3
Goodwill	161.4	161.4
Intangible assets, net of accumulated amortization	110.5	96.8
Current income taxes receivable, net	0.0	1.4
Deferred acquisition costs, net	174.6	160.4
Ceded unearned premiums	515.6	399.5
Other assets	391.0	309.6
Total assets	9,279.7	8,764.0
Liabilities and Shareholders' Equity
Reserves for losses and loss adjustment expenses	4,291.7	4,201.0
Unearned premiums	1,387.5	1,207.7
Accrued underwriting expenses	122.6	115.3
Ceded reinsurance payable, net	885.4	734.0
Funds held	38.8	42.7
Senior unsecured fixed rate notes	139.8	139.6
Other indebtedness	183.9	184.5
Junior subordinated debentures	256.9	256.6
Current income taxes payable, net	8.1	0.0
Deferred tax liabilities, net	14.0	31.3
Other liabilities	132.9	31.6
Total liabilities	7,461.6	6,944.3
Commitments and contingencies (Note 14)
Shareholders' equity:
Common shares - $1.00 par, 500,000,000 shares authorized; 45,188,722 and 40,385,309 shares issued at September 30, 2018 and December 31, 2017, respectively	45.2	40.4
Additional paid-in capital	1,368.7	1,129.1
Treasury shares (11,285,996 and 10,785,007 shares at September 30, 2018 and December 31, 2017, respectively)	(453.4)	(423.4)
Retained earnings	915.7	977.0
Accumulated other comprehensive (loss) income, net of taxes	(58.1)	96.6
Total shareholders' equity	1,818.1	1,819.7
Total liabilities and shareholders' equity	$ 9,279.7	$ 8,764.0

[1] Derived from audited consolidated financial statements.