Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017	[1]
Investments:
Fixed maturities available-for-sale, at fair value (cost: 2018 - $3,338.5; 2017 - $3,320.6)	$ 3,301.4	$ 3,343.4
Equity securities, at fair value (cost: 2018 - $368.8; 2017 - $338.2)	492.2	487.4
Other investments (cost: 2018 - $516.3; 2017 - $534.1)	525.9	543.6
Short-term investments, at fair value (cost: 2018 - $449.4; 2017 - $368.5)	449.4	368.5
Total investments	4,768.9	4,742.9
Cash	126.7	176.6
Accrued investment income	24.9	23.5
Premiums receivable	698.1	598.6
Reinsurance recoverables	2,131.6	2,093.3
Goodwill	161.4	161.4
Intangible assets, net of accumulated amortization	111.9	96.8
Current income taxes receivable, net	0.0	1.4
Deferred acquisition costs, net	161.1	160.4
Ceded unearned premiums	493.4	399.5
Other assets	427.7	309.6
Total assets	9,105.7	8,764.0
Liabilities and Shareholders' Equity
Reserves for losses and loss adjustment expenses	4,242.9	4,201.0
Unearned premiums	1,283.6	1,207.7
Accrued underwriting expenses	116.1	115.3
Ceded reinsurance payable, net	816.0	734.0
Funds held	40.8	42.7
Senior unsecured fixed rate notes	139.7	139.6
Other indebtedness	184.6	184.5
Junior subordinated debentures	256.8	256.6
Current income taxes payable, net	13.5	0.0
Deferred tax liabilities, net	15.1	31.3
Other liabilities	199.5	31.6
Total liabilities	7,308.6	6,944.3
Commitments and contingencies (Note 14)
Shareholders' equity:
Common shares - $1.00 par, 500,000,000 shares authorized; 45,144,646 and 40,385,309 shares issued at June 30, 2018 and December 31, 2017, respectively	45.1	40.4
Additional paid-in capital	1,365.3	1,129.1
Treasury shares (11,129,540 and 10,785,007 shares at June 30, 2018 and December 31, 2017, respectively)	(443.8)	(423.4)
Retained earnings	884.4	977.0
Accumulated other comprehensive (loss) income, net of taxes	(53.9)	96.6
Total shareholders' equity	1,797.1	1,819.7
Total liabilities and shareholders' equity	$ 9,105.7	$ 8,764.0

[1] Derived from audited consolidated financial statements.