The Hanover Insurance Group, Inc. (THG) 10-Q1 Aug 142014 Q2 Quarterly reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
Document and Entity Information	Jun. 30, 2014	Jul. 30, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Jun-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q2	'
Entity Registrant Name	'HANOVER INSURANCE GROUP, INC.	'
Entity Central Index Key	'0000944695	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	44,189,747

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues	'	'	'	'
Premiums	$1,174.70	$1,090.80	$2,337.70	$2,185.10
Net investment income	67	67.9	134	135.2
Net realized investment gains (losses):	'	'	'	'
Net realized gains from sales and other	22.3	14.8	26.7	23.4
Net other-than-temporary impairment losses on investments recognized in earnings	-0.1	-1.1	-0.1	-1.6
Total net realized investment gains	22.2	13.7	26.6	21.8
Fees and other income	9.1	10.2	18.6	20.8
Total revenues	1,273	1,182.60	2,516.90	2,362.90
Losses and expenses	'	'	'	'
Losses and loss adjustment expenses	725.5	692.1	1,476	1,375.50
Amortization of deferred acquisition costs	259.6	232.7	513.3	475.2
Interest expense	16.3	17.4	32.6	32.1
Other operating expenses	163.9	174.5	315.2	325.3
Total losses and expenses	1,165.30	1,116.70	2,337.10	2,208.10
Income before income taxes	107.7	65.9	179.8	154.8
Income tax expense:	'	'	'	'
Current	-1.6	-0.5	7.6	3.5
Deferred	26.8	13.3	35	31.8
Total income tax expense	25.2	12.8	42.6	35.3
Income from continuing operations	82.5	53.1	137.2	119.5
Net gain from discontinued operations (net of tax benefit (expense) of $0.1 and $(0.1) for the three months ended June 30, 2014 and June 30, 2013 and $0.2 for the six months ended June 30, 2014)	0.1	0.3	'	0.1
Net income	$82.60	$53.40	$137.20	$119.60
Basic:	'	'	'	'
Income from continuing operations	$1.87	$1.21	$3.12	$2.70
Net gain from discontinued operations	$0.01	'	'	'
Net income per share	$1.88	$1.21	$3.12	$2.70
Weighted average shares outstanding	44.1	44	44	44.3
Diluted:	'	'	'	'
Income from continuing operations	$1.84	$1.19	$3.06	$2.65
Net gain from discontinued operations	'	'	'	$0.01
Net income per share	$1.84	$1.19	$3.06	$2.66
Weighted average shares outstanding	44.9	44.8	44.8	45

Consolidated_Statements_of_Inc1

Consolidated Statements of Income (Parenthetical) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014
Income Statement [Abstract]	'	'	'
Net loss from discontinued operations, income tax benefit (expense)	$0.10	($0.10)	$0.20

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Net income	$82.60	$53.40	$137.20	$119.60
Available-for-sale securities and derivative instruments:	'	'	'	'
Net appreciation (depreciation) during the period	34.3	-138.2	81.5	-132.7
Change in other-than-temporary impairment losses recognized in other comprehensive income	'	0.8	1.6	0.7
Total available-for-sale securities and derivative instruments	34.3	-137.4	83.1	-132
Pension and postretirement benefits:	'	'	'	'
Amortization recognized as net periodic benefit and postretirement cost	1.6	4.1	3.4	6
Cumulative foreign currency translation adjustment:	'	'	'	'
Amount recognized as cumulative foreign currency translation during the period	3.1	-0.1	3	-10.1
Total other comprehensive income (loss), net of tax	39	-133.4	89.5	-136.1
Comprehensive income (loss)	$121.60	($80)	$226.70	($16.50)

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets	'	'
Fixed maturities, at fair value (amortized cost of $6,785.1 and $6,815.2)	$7,058.50	$6,970.60
Equity securities, at fair value (cost of $446.4 and $366.5)	530.5	430.2
Other investments	238.5	192.5
Total investments	7,827.50	7,593.30
Cash and cash equivalents	606.2	486.2
Accrued investment income	70	68
Premiums and accounts receivable, net	1,515.90	1,324.60
Reinsurance recoverable on paid and unpaid losses and unearned premiums	2,416.70	2,335
Deferred acquisition costs	540.6	506
Deferred income taxes	145.6	239.7
Goodwill	185.2	184.9
Other assets	542.1	526.1
Assets of discontinued operations	115	114.9
Total assets	13,964.80	13,378.70
Liabilities	'	'
Loss and loss adjustment expense reserves	6,448	6,231.50
Unearned premiums	2,689	2,515.80
Expenses and taxes payable	569.7	637.2
Reinsurance premiums payable	443.2	374.7
Debt	903.9	903.9
Liabilities of discontinued operations	115.9	121.1
Total liabilities	11,169.70	10,784.20
Commitments and contingencies	'	'
Shareholders' Equity	'	'
Preferred stock, par value $0.01 per share; 20.0 million shares authorized; none issued	'	'
Common stock, par value $0.01 per share; 300.0 million shares authorized; 60.5 million shares issued	0.6	0.6
Additional paid-in capital	1,824.50	1,830.10
Accumulated other comprehensive income	267.1	177.6
Retained earnings	1,451.70	1,349.10
Treasury stock at cost (16.6 and 16.8 million shares)	-748.8	-762.9
Total shareholders' equity	2,795.10	2,594.50
Total liabilities and shareholders' equity	$13,964.80	$13,378.70

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Statement Of Financial Position [Abstract]	'	'
Fixed maturities, amortized cost	$6,785.10	$6,815.20
Equity securities, cost	$446.40	$366.50
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, issued	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	60,500,000	60,500,000
Treasury stock, shares	16,600,000	16,800,000

Consolidated_Statements_of_Sha

Consolidated Statements of Shareholders' Equity (USD $)	Preferred Stock [Member]	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss), net of tax	Net Unrealized Appreciation on Investments and Derivative Instruments:	Defined Benefit Pension and Postretirement Plans:	Cumulative Foreign Currency Translation Adjustment:	Retained Earnings	Treasury Stock	Total
In Millions	Preferred Stock [Member]	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss), net of tax		Defined Benefit Pension and Postretirement Plans:	Cumulative Foreign Currency Translation Adjustment:	Retained Earnings	Treasury Stock	Total
Balance at beginning of period at Dec. 31, 2012	'	$0.60	$1,787.10	'	$426	($96.60)	($3.60)	$1,211.60	($729.70)	'
Net income	'	'	'	'	'	'	'	119.6	'	119.6
Shares purchased at cost	'	'	'	'	'	'	'	'	-72.3	'
Employee and director stock-based awards and other	'	'	6	'	'	'	'	'	'	'
Net appreciation on available-for-sale securities and derivative instruments	'	'	'	'	-132	'	'	'	'	-132
Net amount recognized as net periodic benefit cost	'	'	'	'	'	6	'	'	'	'
Amount recognized as cumulative foreign currency translation during the period	'	'	'	'	'	'	-10.1	'	'	-10.1
Dividends to shareholders	'	'	'	'	'	'	'	-29.3	'	'
Total accumulated other comprehensive income	'	'	'	'	'	'	'	'	'	-136.1
Net shares reissued at cost under employee stock-based compensation plans	'	'	'	'	'	'	'	'	31.9	'
Stock-based compensation	'	'	'	'	'	'	'	-19.5	'	'
Balance at end of period at Jun. 30, 2013	'	0.6	1,793.10	189.7	294	-90.6	-13.7	1,282.40	-770.1	2,495.70
Balance at beginning of period at Dec. 31, 2013	'	0.6	1,830.10	'	259.3	-76.1	-5.6	1,349.10	-762.9	2,594.50
Net income	'	'	'	'	'	'	'	137.2	'	137.2
Shares purchased at cost	'	'	'	'	'	'	'	'	-6.7	'
Employee and director stock-based awards and other	'	'	-5.6	'	'	'	'	'	'	'
Net appreciation on available-for-sale securities and derivative instruments	'	'	'	'	83.1	'	'	'	'	83.1
Net amount recognized as net periodic benefit cost	'	'	'	'	'	3.4	'	'	'	'
Amount recognized as cumulative foreign currency translation during the period	'	'	'	'	'	'	3	'	'	3
Dividends to shareholders	'	'	'	'	'	'	'	-32.6	'	'
Total accumulated other comprehensive income	'	'	'	'	'	'	'	'	'	89.5
Net shares reissued at cost under employee stock-based compensation plans	'	'	'	'	'	'	'	'	20.8	'
Stock-based compensation	'	'	'	'	'	'	'	-2	'	'
Balance at end of period at Jun. 30, 2014	'	$0.60	$1,824.50	$267.10	$342.40	($72.70)	($2.60)	$1,451.70	($748.80)	$2,795.10

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash Flows From Operating Activities	'	'
Net income	$137.20	$119.60
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Loss on repurchase of debt	'	11.3
Net realized investment gains	-26.6	-21.8
Net amortization and depreciation	16.9	17.4
Stock-based compensation expense	7.3	5.7
Amortization of defined benefit plan costs	5.2	9.2
Deferred income taxes expense	34.9	31.8
Change in deferred acquisition costs	-34.6	-20.2
Change in premiums receivable, net of reinsurance premiums payable	-122.8	-115.7
Change in loss, loss adjustment expense and unearned premium reserves	352.2	80.8
Change in reinsurance recoverable	-69.9	45.3
Change in expenses and taxes payable	-101.8	-111.4
Other, net	-30.6	-18.7
Net cash provided by operating activities	167.4	33.3
Cash Flows From Investing Activities	'	'
Proceeds from disposals and maturities of fixed maturities	669	869.5
Proceeds from disposals of equity securities and other investments	95.3	85.1
Purchase of fixed maturities	-583.4	-603.8
Purchase of equity securities and other investments	-196.4	-206.9
Capital expenditures	-7.4	-10.7
Net cash (used in) provided by investing activities	-22.9	133.2
Cash Flows From Financing Activities	'	'
Proceeds from exercise of employee stock options	6.7	15.1
Proceeds from debt borrowings, net	'	169.5
Change in cash collateral related to securities lending program	2	-17.7
Dividends paid to shareholders	-32.6	-29.3
Repurchases of debt	-0.1	-96.8
Repurchases of common stock	-6.7	-72.3
Other financing activities	-2.3	-3.3
Net cash used in financing activities	-33	-34.8
Effect of exchange rate changes on cash	8.5	-6.2
Net change in cash and cash equivalents	120	125.5
Net change in cash related to discontinued operations	'	0.1
Cash and cash equivalents, beginning of period	486.2	564.8
Cash and cash equivalents, end of period	$606.20	$690.40

Basis_of_Presentation_and_Prin

Basis of Presentation and Principles of Consolidation	6 Months Ended
Basis of Presentation and Principles of Consolidation	Jun. 30, 2014
Basis of Presentation and Principles of Consolidation [Abstract]	'
Basis of Presentation and Principles of Consolidation	'
	1. Basis of Presentation and Principles of Consolidation
	The accompanying unaudited consolidated financial statements of The Hanover Insurance Group, Inc. and subsidiaries (“THG” or the “Company”) have been prepared in accordance with generally accepted accounting principles in the United States of America (“U.S. GAAP”) for interim financial information and with the requirements of Form 10-Q. Certain financial information that is provided in annual financial statements, but is not required in interim reports, has been omitted.
	The interim consolidated financial statements of THG include the accounts of The Hanover Insurance Company (“Hanover Insurance”) and Citizens Insurance Company of America, THG’s principal U.S. domiciled property and casualty companies; Chaucer Holdings plc (“Chaucer”), a specialist insurance underwriting group which operates through the Society and Corporation of Lloyd’s (“Lloyd’s”) and certain other insurance and non-insurance subsidiaries. These legal entities conduct their operations through several business segments discussed in Note 8 – “Segment Information”. Additionally, the interim consolidated financial statements include the Company’s discontinued operations, consisting primarily of the Company’s former life insurance businesses and its accident and health business. All intercompany accounts and transactions have been eliminated.
	The preparation of financial statements in conformity with U.S. GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amount of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	In the opinion of the Company’s management, the accompanying interim consolidated financial statements reflect all adjustments, consisting of normal recurring items, necessary for a fair presentation of the financial position and results of operations. The results of operations for the three and six months ended June 30, 2014 are not necessarily indicative of the results to be expected for the full year. These financial statements should be read in conjunction with the Company’s 2013 Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on February 25, 2014.

New_Accounting_Pronouncements

New Accounting Pronouncements	6 Months Ended
New Accounting Pronouncements	Jun. 30, 2014
New Accounting Pronouncements [Abstract]	'
New Accounting Pronouncements	'
	2. New Accounting Pronouncements
	Recently Implemented Standards
	In July 2013, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Codification (“ASC”) Update No. 2013-11 (Topic 740) Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force). This ASC update clarifies the applicable guidance for the presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. An unrecognized tax benefit, or a portion of an unrecognized tax benefit, should be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward as long as it is available, at the reporting date under the tax law of the applicable jurisdiction, to settle any additional income taxes that would result from the disallowance of a tax position (with certain exceptions). The assessment of whether a deferred tax asset is available is based on the unrecognized tax benefit and deferred tax asset that exist at the reporting date and should be made presuming disallowance of the tax position at the reporting date. This guidance was applicable for reporting periods beginning after December 15, 2013, with early adoption permitted, and was to be applied prospectively to all unrecognized tax benefits that existed at the effective date. Retrospective application to all prior periods upon the date of adoption was permitted. The Company implemented this guidance effective January 1, 2014. The effect of implementing this guidance was not material to the Company’s financial position or results of operations.
	In March 2013, the FASB issued ASC Update No. 2013-05 (Topic 830) Foreign Currency Matters-Parent’s Accounting for the Cumulative Translation Adjustment upon Derecognition of Certain Subsidiaries or Groups of Assets within a Foreign Entity or of an Investment in a Foreign Entity (a consensus of the FASB Emerging Issues Task Force). This ASC update clarifies the applicable guidance for the release of the cumulative translation adjustment into net income when a parent either sells all or a portion of its investment in a foreign entity. This guidance is also required to be applied when an entity no longer holds a controlling financial interest in a subsidiary or group of assets that is a nonprofit activity or a business within a foreign entity (with certain exceptions). Additionally, this update clarifies that the sale of an investment in a foreign entity includes events that result in an acquirer obtaining control of an acquiree in which it held an equity interest immediately before the acquisition date in a business combination achieved in stages. This guidance was applicable for reporting periods beginning after December 15, 2013, with early adoption permitted, and was to be applied prospectively to derecognition events occurring after the effective date. The Company implemented this guidance effective January 1, 2014. The effect of implementing this guidance was not material to the Company’s financial position or results of operations.

	Recently Issued Standards
	In April 2014, the FASB issued ASC Update No. 2014-08 (Topic 205 and Topic 360) Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity. This ASC update modifies the definition of discontinued operations by limiting discontinued operations reporting to disposals of components of an entity that represent strategic shifts that have (or will have) a major effect on an entity’s operations and financial results. Also, this update requires additional financial statement disclosures about discontinued operations, as well as disposals of an individually significant component of an entity that do not qualify for discontinued operations presentation. This ASC update is effective for all disposals (or classifications as held for sale) of components of an entity that occur within annual and interim periods beginning on or after December 15, 2014 and for all businesses that, on acquisition, are classified as held for sale that also occur within interim and annual periods beginning on or after December 15, 2014. Early adoption is permitted for disposals (or classifications as held for sale) that have not been reported in financial statements previously issued or available for issuance. The Company does not expect the adoption of ASC Update 2014-08 to have a material impact on its financial position or results of operations.
	In May 2014, the FASB issued ASC Update No. 2014-09 (Topic 606) Revenue from Contracts with Customers. This ASC was issued to clarify the principles for recognizing revenue. Insurance Contracts and financial instrument transactions are not within the scope of this updated guidance, and; therefore, only an insignificant amount of the Company’s revenue is subject to this updated guidance. The updated guidance is effective for periods beginning after December 15, 2016 and is not expected to have a material effect on the Company’s financial position or results of operations.

Income_Taxes

Income Taxes	6 Months Ended
Income Taxes	Jun. 30, 2014
Income Taxes [Abstract]	'
Income Taxes	'
	3. Income Taxes
	Income tax expense for the six months ended June 30, 2014 and 2013 has been computed using estimated annual effective tax rates. These rates are revised, if necessary, at the end of each successive interim period to reflect current estimates of the annual effective tax rates.
	For the six months ended June 30, 2014, the tax provision is comprised of a $24.7 million U.S. federal income tax expense and a $17.9 million foreign income tax expense. For the six months ended June 30, 2013, the tax provision was comprised of a $17.6 million U.S. federal income tax expense and a $17.7 million foreign income tax expense. Income tax expense for the six months ended June 30, 2014 included a benefit of $4.4 million related to foreign exchange losses that will be deductible on the Company’s 2013 U.S. tax return. This permanent tax item is not otherwise recognized in the Company’s U.S. GAAP financial statements.
	Although most of the Company’s non–U.S. income is subject to U.S. federal income tax, certain of its non–U.S. income is not subject to U.S. federal income tax until repatriated. Foreign taxes on this non–U.S. income are accrued at the local foreign tax rate, as opposed to the higher U.S. statutory rate, since these earnings currently are expected to be indefinitely reinvested overseas. This assumption could change as a result of a sale of the subsidiaries, the receipt of dividends from the subsidiaries, a change in management’s intentions, or as a result of various other events. The Company has not made a provision for U.S. taxes on $5.6 million and $10.3 million of non-U.S. income for the six months ended June 30, 2014 and 2013, respectively. However, in the future, if such earnings were distributed to the Company, taxes of $14.9 million would be payable on such undistributed earnings and would be reflected in the tax provision for the year in which these earnings are no longer intended to be indefinitely reinvested overseas, assuming all foreign tax credits are realized.
	In May 2014, the Company reached a final settlement with the IRS for years 2007 and 2008, related to the disallowance of deductions for certain loss reserves. As a result, a liability for uncertain tax positions was established for $4.8 million, with an offsetting deferred tax asset. The IRS audits of the years 2009 and 2010 commenced in June 2012 and final settlement was reached in May 2014 with no additional tax liability.
	The Company or its subsidiaries files income tax returns in the U.S. federal jurisdiction and various state jurisdictions, as well as foreign jurisdictions. With few exceptions, the Company and its subsidiaries are no longer subject to U.S. federal income tax examinations by tax authorities for years before 2011. The Company and its subsidiaries are still subject to U.S. state income tax examinations by tax authorities for years after 2006 and foreign examinations for years after 2011.

Investments

Investments	6 Months Ended
Investments	Jun. 30, 2014
Investments [Abstract]	'
Investments	'
	4. Investments
	A. Fixed maturities and equity securities
	The amortized cost and fair value of available-for-sale fixed maturities and the cost and fair value of equity securities were as follows:



			30-Jun-14
			Amortized			Gross			Gross						OTTI
			Cost or			Unrealized			Unrealized						Unrealized
	(in millions)		Cost			Gains			Losses			Fair Value			Losses
	Fixed maturities:
	U.S. Treasury and government agencies		$	403.5		$	6.0		$	6.3		$	403.2		$	-
	Foreign government			319.7			2.6			1.3			321.0			-
	Municipal			1,080.4			59.5			6.4			1,133.5			-
	Corporate			3,718.3			205.4			15.0			3,908.7			7.4
	Residential mortgage-backed			697.3			22.1			5.8			713.6			0.4
	Commercial mortgage-backed			395.1			12.5			1.5			406.1			-
	Asset-backed			170.8			1.7			0.1			172.4			-
	Total fixed maturities		$	6,785.1		$	309.8		$	36.4		$	7,058.5		$	7.8
	Equity securities		$	446.4		$	84.9		$	0.8		$	530.5		$	-








			31-Dec-13
			Amortized			Gross			Gross						OTTI
			Cost or			Unrealized			Unrealized						Unrealized
	(in millions)		Cost			Gains			Losses			Fair Value			Losses
	Fixed maturities:
	U.S. Treasury and government agencies		$	417.5		$	3.3		$	14.2		$	406.6		$	-
	Foreign government			304.5			2.1			1.6			305.0			-
	Municipal			1,108.0			37.4			19.1			1,126.3			-
	Corporate			3,690.2			171.5			37.5			3,824.2			8.6
	Residential mortgage-backed			722.8			20.1			14.1			728.8			1.6
	Commercial mortgage-backed			405.9			10.5			4.8			411.6			-
	Asset-backed			166.3			2.0			0.2			168.1			-
	Total fixed maturities		$	6,815.2		$	246.9		$	91.5		$	6,970.6		$	10.2
	Equity securities		$	366.5		$	66.9		$	3.2		$	430.2		$	-

	Other-than-temporary impairments (“OTTI”) unrealized losses in the tables above represent OTTI recognized in accumulated other comprehensive income. This amount excludes net unrealized gains on impaired securities relating to changes in the value of such securities subsequent to the impairment measurement date of $14.4 million and $16.4 million as of June 30, 2014 and December 31, 2013, respectively.

	The amortized cost and fair value by maturity periods for fixed maturities are shown below. Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties, or the Company may have the right to put or sell the obligations back to the issuers.



			30-Jun-14
			Amortized			Fair
	(in millions)		Cost			Value
	Due in one year or less		$	400.6		$	404.8
	Due after one year through five years			2,329.2			2,437.4
	Due after five years through ten years			2,116.5			2,215.1
	Due after ten years			675.6			709.1
				5,521.9			5,766.4
	Mortgage-backed and asset-backed securities			1,263.2			1,292.1
	Total fixed maturities		$	6,785.1		$	7,058.5







B. Securities in an unrealized loss position
The following tables provide information about the Company’s fixed maturities and equity securities that were in an unrealized loss position at June 30, 2014 and December 31, 2013.





		30-Jun-14
		12 months or less						Greater than 12 months						Total
		Gross						Gross						Gross
		Unrealized			Fair			Unrealized			Fair			Unrealized			Fair
(in millions)		Losses			Value			Losses			Value			Losses			Value
Fixed maturities:
Investment grade:
U.S. Treasury and government agencies		$	-		$	6.4		$	6.3		$	152.0		$	6.3		$	158.4
Foreign governments			0.8			100.7			0.5			56.1			1.3			156.8
Municipal			0.4			53.3			5.7			158.9			6.1			212.2
Corporate			2.6			198.4			10.1			259.7			12.7			458.1
Residential mortgage-backed			0.5			39.7			5.3			135.5			5.8			175.2
Commercial mortgage-backed			0.1			31.3			1.4			65.4			1.5			96.7
Asset-backed			-			10.7			0.1			14.2			0.1			24.9
Total investment grade			4.4			440.5			29.4			841.8			33.8			1,282.3
Below investment grade:
Municipal			0.3			4.4			-			-			0.3			4.4
Corporate			0.5			16.2			1.8			25.0			2.3			41.2
Total below investment grade			0.8			20.6			1.8			25.0			2.6			45.6
Total fixed maturities			5.2			461.1			31.2			866.8			36.4			1,327.9
Equity securities			-			10.0			0.8			3.4			0.8			13.4
Total		$	5.2		$	471.1		$	32.0		$	870.2		$	37.2		$	1,341.3





		31-Dec-13
		12 months or less						Greater than 12 months						Total
		Gross						Gross						Gross
		Unrealized			Fair			Unrealized			Fair			Unrealized			Fair
(in millions)		Losses			Value			Losses			Value			Losses			Value
Fixed maturities:
Investment grade:
U.S. Treasury and government agencies		$	12.3		$	247.9		$	1.9		$	18.8		$	14.2		$	266.7
Foreign governments			1.5			129.0			0.1			17.3			1.6			146.3
Municipal			14.8			345.3			4.3			39.9			19.1			385.2
Corporate			21.4			872.7			11.6			87.7			33.0			960.4
Residential mortgage-backed			10.3			321.1			3.4			29.5			13.7			350.6
Commercial mortgage-backed			4.2			155.4			0.6			10.2			4.8			165.6
Asset-backed			0.2			31.0			-			0.3			0.2			31.3
Total investment grade			64.7			2,102.4			21.9			203.7			86.6			2,306.1
Below investment grade:
Corporate			2.9			71.9			1.6			21.4			4.5			93.3
Residential mortgage-backed			0.1			2.0			0.3			1.5			0.4			3.5
Total below investment grade			3.0			73.9			1.9			22.9			4.9			96.8
Total fixed maturities			67.7			2,176.3			23.8			226.6			91.5			2,402.9
Equity securities			2.8			45.2			0.4			0.7			3.2			45.9
Total		$	70.5		$	2,221.5		$	24.2		$	227.3		$	94.7		$	2,448.8





The Company views gross unrealized losses on fixed maturities and equity securities as being temporary since it is its assessment that these securities will recover in the near term, allowing the Company to realize the anticipated long-term economic value. The Company employs a systematic methodology to evaluate declines in fair value below amortized cost for fixed maturity securities or cost for equity securities. In determining OTTI of fixed maturity and equity securities, the Company evaluates several factors and circumstances, including the issuer’s overall financial condition; the issuer’s credit and financial strength ratings; the issuer’s financial performance, including earnings trends, dividend payments and asset quality; any specific events which may influence the operations of the issuer; the general outlook for market conditions in the industry or geographic region in which the issuer operates; and the length of time and the degree to which the fair value of an issuer’s securities remains below the Company’s cost. With respect to fixed maturity investments, the Company considers any factors that might raise doubt about the issuer’s ability to make contractual payments as they come due and whether the Company expects to recover the entire amortized cost basis of the security. With respect to equity securities, the Company considers its ability and intent to hold the investment for a period of time to allow for a recovery in value.
C. Proceeds from sales
The proceeds from sales of available-for-sale securities and gross realized gains and losses on those sales, were as follows:




		Three Months Ended June 30,
		2014									2013
		Proceeds from			Gross			Gross			Proceeds from			Gross			Gross
(in millions)		Sales			Gains			Losses			Sales			Gains			Losses
Fixed maturities		$	70.5		$	1.1		$	1.1		$	148.5		$	3.0		$	0.4
Equity securities		$	60.0		$	22.2		$	0.7		$	44.4		$	10.4		$	0.3





		Six Months Ended June 30,
		2014									2013
		Proceeds from			Gross			Gross			Proceeds from			Gross			Gross
(in millions)		Sales			Gains			Losses			Sales			Gains			Losses
Fixed maturities		$	208.1		$	3.3		$	2.3		$	285.7		$	4.6		$	1.0
Equity securities		$	72.4		$	24.1		$	0.8		$	78.9		$	17.0		$	0.3

D. Other-than-temporary impairments
For the three and six months ended June 30, 2014, OTTI of fixed maturities recognized in earnings was $0.1 million, which was transferred from unrealized losses in accumulated other comprehensive income.
For the three months ended June 30, 2013, total OTTI of fixed maturities and equity securities were $1.3 million. Of this amount, $1.1 million was recognized in earnings and the remaining $0.2 million was recorded as unrealized losses in accumulated other comprehensive income. For the first six months of 2013, total OTTI of fixed maturities and equities were $2.0 million. Of this amount, $1.6 million was recognized in earnings and the remaining $0.4 million was recorded as unrealized losses in accumulated other comprehensive income.
There were no credit impairments in 2014. The methodology and significant inputs used to measure the amount of credit losses on fixed maturities in 2013 were as follows:
Asset-backed securities, including commercial and residential mortgage-backed securities – the Company utilized cash flow estimates based on bond specific facts and circumstances that include collateral characteristics, expectations of delinquency and default rates, loss severity, prepayment speeds and structural support, including subordination and guarantees.



The following table provides rollforwards of the cumulative amounts related to the Company’s credit loss portion of the OTTI losses on fixed maturity securities for which the non-credit portion of the loss is included in other comprehensive income.





		Three Months Ended June 30,						Six Months Ended June 30,
(in millions)		2014			2013			2014			2013
Credit losses at beginning of period		$	5.3		$	8.6		$	7.8		$	8.6
Credit losses for which an OTTI was not			-			0.1			-			0.3
previously recognized			-			0.1			-			0.3
Additional credit losses on securities for which an
OTTI was previously recognized			-			-			-			0.2
Reductions for securities sold, matured or called			-0.6			-1.4			-3.1			-1.8
Reductions for securities reclassified as intended to sell			-0.4			-			-0.4			-
Credit losses at the end of period		$	4.3		$	7.3		$	4.3		$	7.3

E. Funds at Lloyd’s
In accordance with Lloyd’s operating guidelines, the Company deposits funds at Lloyd’s to support underwriting operations. These funds are available only to fund claim obligations. These assets consisted of approximately $403 million of fixed maturities and $75 million of cash and cash equivalents as of June 30, 2014. The Company also deposits funds with various state and governmental authorities in the U.S. For a discussion of the Company’s deposits with state and governmental authorities, see also Note 3 – “Investments” of the Notes to Consolidated Financial Statements in our Annual Report on Form 10-K for the year ended December 31, 2013.

Fair_Value

Fair Value	6 Months Ended
Fair Value	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value	'
	5. Fair Value
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability, i.e., exit price, in an orderly transaction between market participants. The Company emphasizes the use of observable market data whenever available in determining fair value. Fair values presented for certain financial instruments are estimates which, in many cases, may differ significantly from the amounts that could be realized upon immediate liquidation. A hierarchy of the three broad levels of fair value are as follows, with the highest priority given to Level 1 as these are the most observable, and the lowest priority given to Level 3:
	Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities.
	Level 2 – Quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data, including model-derived valuations.
	Level 3 – Unobservable inputs that are supported by little or no market activity.
	When more than one level of input is used to determine fair value, the financial instrument is classified as Level 2 or 3 according to the lowest level input that has a significant impact on the fair value measurement.
	The following methods and assumptions were used to estimate the fair value of each class of financial instruments and have not changed since last year.
	Cash and Cash Equivalents
	The carrying amount approximates fair value. Cash equivalents primarily consist of money market instruments, which are generally valued using unadjusted quoted prices in active markets that are accessible for identical assets and are classified as Level 1.



	Fixed Maturities
	Level 1 securities generally include U.S. Treasury issues and other securities that are highly liquid and for which quoted market prices are available. Level 2 securities are valued using pricing for similar securities and pricing models that incorporate observable inputs including, but not limited to yield curves and issuer spreads. Level 3 securities include issues for which little observable data can be obtained, primarily due to the illiquid nature of the securities, and for which significant inputs used to determine fair value are based on the Company’s own assumptions. Non-binding broker quotes are also included in Level 3.
	The Company utilizes a third party pricing service for the valuation of the majority of its fixed maturity securities and receives one quote per security. When quoted market prices in an active market are available, they are provided by the pricing service as the fair value and such values are classified as Level 1. Since fixed maturities other than U.S. Treasury securities generally do not trade on a daily basis, the pricing service prepares estimates of fair value for those securities using pricing applications based on a market approach. Inputs into the fair value pricing common to all asset classes include: benchmark U.S. Treasury security yield curves; reported trades of identical or similar fixed maturity securities; broker/dealer quotes of identical or similar fixed maturity securities and structural characteristics such as maturity date, coupon, mandatory principal payment dates, frequency of interest and principal payments, and optional redemption features. Inputs into the fair value applications that are unique by asset class include, but are not limited to:
	• U.S. government agencies – determination of direct versus indirect government support and whether any contingencies exist with respect to the timely payment of principal and interest.
	• Foreign government – estimates of appropriate market spread versus underlying related sovereign treasury curve(s) dependent on liquidity and direct or contingent support.
	• Municipals – overall credit quality, including assessments of the level and variability of: sources of payment such as income, sales or property taxes, levies or user fees; credit support such as insurance; state or local economic and political base; natural resource availability; and susceptibility to natural or man-made catastrophic events such as hurricanes, earthquakes or acts of terrorism.
	• Corporate fixed maturities – overall credit quality, including assessments of the level and variability of: economic sensitivity; liquidity; corporate financial policies; management quality; regulatory environment; competitive position; ownership; restrictive covenants; and security or collateral.
	•Residential mortgage-backed securities – estimates of prepayment speeds based upon: historical prepayment rate trends; underlying collateral interest rates; geographic concentration; vintage year; borrower credit quality characteristics; interest rate and yield curve forecasts; government or monetary authority support programs; tax policies; delinquency/default trends; and, in the case of non-agency collateralized mortgage obligations, severity of loss upon default and length of time to recover proceeds following default.
	• Commercial mortgage-backed securities – overall credit quality, including assessments of the value and supply/demand characteristics of: collateral type such as office, retail, residential, lodging, or other; geographic concentration by region, state, metropolitan statistical area and locale; vintage year; historical collateral performance including defeasance, delinquency, default and special servicer trends; and capital structure support features.
	•Asset-backed securities – overall credit quality, including assessments of the underlying collateral type such as credit card receivables, auto loan receivables and equipment lease receivables; geographic diversification; vintage year; historical collateral performance including delinquency, default and casualty trends; economic conditions influencing use rates and resale values; and contract structural support features.
	Generally, all prices provided by the pricing service, except actively traded securities with quoted market prices, are reported as Level 2.
	The Company holds privately placed fixed maturity securities and certain other fixed maturity securities that do not have an active market and for which the pricing service cannot provide fair values. The Company determines fair values for these securities using either matrix pricing utilizing the market approach or broker quotes. The Company will use observable market data as inputs into the fair value applications, as discussed in the determination of Level 2 fair values, to the extent it is available, but is also required to use a certain amount of unobservable judgment due to the illiquid nature of the securities involved. Unobservable judgment reflected in the Company’s matrix model accounts for estimates of additional spread required by market participants for factors such as issue size, structural complexity, high bond coupon or other unique features. These matrix-priced securities are reported as Level 2 or Level 3, depending on the significance of the impact of unobservable judgment on the security’s value. Additionally, the Company may obtain non-binding broker quotes which are reported as Level 3.
	Equity Securities
	Level 1 consists of publicly traded securities, including exchange traded funds, valued at quoted market prices. Level 2 includes securities that are valued using pricing models that incorporate observable inputs. Level 3 consists of common or preferred stock of private companies for which observable inputs are not available. Non-binding broker quotes are also included in Level 3.
	The Company utilizes a third party pricing service for the valuation of the majority of its equity securities and receives one quote for each equity security. When quoted market prices in an active market are available, they are provided by the pricing service as the fair value and such values are classified as Level 1. The Company holds certain equity securities that have been issued by privately-held entities that do not have an active market and for which the pricing service cannot provide fair values. Generally, the Company estimates fair value for these securities based on the issuer’s book value and market multiples. These securities are reported as Level 2 or Level 3 depending on the significance of the impact of unobservable judgment on the security’s value.
	Other Investments
	Other investments consist primarily of overseas trust funds, for which fair values are provided by the investment manager based on quoted prices for similar instruments in active markets and are reported as Level 2. Also included in other investments are mortgage and other loans and cost basis limited partnerships. Fair values of mortgage and other loans are estimated by discounting the future contractual cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and are reported as Level 2. The fair values of cost basis limited partnerships are based on the net asset value provided by the general partner and recent financial information and are reported as Level 3.
	Debt
	The fair value of debt is estimated based on quoted market prices. If a quoted market price is not available, fair values are estimated using discounted cash flows that are based on current interest rates and yield curves for debt issuances with maturities and credit risks consistent with the debt being valued. Debt is reported as Level 2.
	The estimated fair value of the financial instruments were as follows:



			30-Jun-14						31-Dec-13
			Carrying			Fair			Carrying			Fair
	(in millions)		Value			Value			Value			Value
	Financial Assets
	Cash and cash equivalents		$	606.2		$	606.2		$	486.2		$	486.2
	Fixed maturities			7,058.5			7,058.5			6,970.6			6,970.6
	Equity securities			530.5			530.5			430.2			430.2
	Other investments			218.4			220.9			173.1			173.7
	Total financial assets		$	8,413.6		$	8,416.1		$	8,060.1		$	8,060.7
	Financial Liabilities
	Debt		$	903.9		$	1,030.7		$	903.9		$	961.7
	The Company has processes designed to ensure that the values received from its third party pricing service are accurately recorded, that the data inputs and valuation techniques utilized are appropriate and consistently applied and that the assumptions are reasonable and consistent with the objective of determining fair value. The Company performs a review of the fair value hierarchy classifications and of prices received from its pricing service on a quarterly basis. The Company reviews the pricing services’ policies describing its methodology, processes, practices and inputs, including various financial models used to value securities. Also, the Company reviews the portfolio pricing, including securities with changes in prices that exceed a defined threshold being verified to independent sources, if available. If upon review, the Company is not satisfied with the validity of a given price, a pricing challenge would be submitted to the pricing service along with supporting documentation for its review. The Company does not adjust quotes or prices obtained from the pricing service unless the pricing service agrees with the Company’s challenge. During 2014 and 2013, the Company did not adjust any prices received from brokers or its pricing service.



	Changes in the observability of valuation inputs may result in a reclassification of certain financial assets or liabilities within the fair value hierarchy. Reclassifications between levels of the fair value hierarchy are reported as of the beginning of the period in which the reclassification occurs. As previously discussed, the Company utilizes a third party pricing service for the valuation of the majority of its fixed maturities and equity securities. The pricing service has indicated that it will only produce an estimate of fair value if there is objectively verifiable information to produce a valuation. If the pricing service discontinues pricing an investment, the Company will use observable market data to the extent it is available, but may also be required to make assumptions for market based inputs that are unavailable due to market conditions.

	The following tables provide, for each hierarchy level, the Company’s assets that were measured at fair value on a recurring basis.





			30-Jun-14
	(in millions)			Total			Level 1			Level 2			Level 3
	Fixed maturities:
	U.S. Treasury and government agencies		$	403.2		$	160.5		$	242.7		$	-
	Foreign government			321.0			42.8			278.2			-
Municipal			1,133.5			-			1,106.7			26.8
Corporate			3,908.7			-			3,895.5			13.2
Residential mortgage-backed, U.S. agency backed			586.2			-			586.2			-
Residential mortgage-backed, non-agency			127.4			-			127.4			-
Commercial mortgage-backed			406.1			-			383.6			22.5
Asset-backed			172.4			-			172.4			-
Total fixed maturities			7,058.5			203.3			6,792.7			62.5
Equity securities			521.2			520.0			-			1.2
Other investments			138.5			-			134.9			3.6
Total investment assets at fair value		$	7,718.2		$	723.3		$	6,927.6		$	67.3




		31-Dec-13
(in millions)			Total			Level 1			Level 2			Level 3
Fixed maturities:
U.S. Treasury and government agencies		$	406.6		$	167.2		$	239.4		$	-
Foreign government			305.0			45.6			259.4			-
Municipal			1,126.3			-			1,100.7			25.6
Corporate			3,824.2			-			3,811.2			13.0
Residential mortgage-backed, U.S. agency backed			573.2			-			573.2			-
Residential mortgage-backed, non-agency			155.6			-			155.1			0.5
Commercial mortgage-backed			411.6			-			388.7			22.9
Asset-backed			168.1			-			168.1			-
Total fixed maturities			6,970.6			212.8			6,695.8			62.0
Equity securities			420.9			382.3			-			38.6
Other investments			153.2			-			149.6			3.6
Total investment assets at fair value		$	7,544.7		$	595.1		$	6,845.4		$	104.2




The following tables provide, for each hierarchy level, the Company’s estimated fair values of financial instruments that were not carried at fair value:





			30-Jun-14
(in millions)			Total			Level 1			Level 2			Level 3
Assets:
Cash and cash equivalents		$	606.2		$	606.2		$	-		$	-
Equity securities			9.3			-			9.3			-
Other investments			82.4			-			58.6			23.8
Liabilities:
Debt		$	1,030.7		$	-		$	1,030.7		$	-


			31-Dec-13
(in millions)			Total			Level 1			Level 2			Level 3
Assets:
Cash and cash equivalents		$	486.2		$	486.2		$	-		$	-
Equity securities			9.3			-			9.3			-
Other investments			20.5			-			2.7			17.8
Liabilities:
Debt		$	961.7		$	-		$	961.7		$	-





The tables below provide a reconciliation for all assets measured at fair value on a recurring basis using significant unobservable inputs (Level 3).





			Fixed Maturities
(in millions)		Municipal			Corporate			Residential mortgage-backed, non-agency			Commercial mortgage-backed			Total		Equity and Other		Total Assets
Three Months Ended
30-Jun-14
Balance April 1, 2014		$	29.6		$	13.2		$	-		$	22.5		$	65.3	$	4.8	$	70.1
Transfers out of Level 3			-2.6			-			-			-			-2.6		-		-2.6
Total gains:															-
Included in other comprehensive income - net appreciation on available-for-sale securities			0.3			-			-			0.4			0.7		-		0.7
Sales			-0.5			-			-			-0.4			-0.9		-		-0.9
Balance June 30, 2014		$	26.8		$	13.2		$	-		$	22.5		$	62.5	$	4.8	$	67.3

Three Months Ended
30-Jun-13
Balance April 1, 2013		$	28.8		$	22.8		$	0.6		$	24.8		$	77.0	$	28.6	$	105.6
Transfers out of Level 3			-			-2.2			-			-			-2.2		-		-2.2
Total gains (losses):
Included in other comprehensive income - net (depreciation) appreciation on available-for-sale securities			-0.4			-0.9			-			-0.9			-2.2		3.7		1.5
Sales			-0.5			-0.2			-			-0.3			-1		-		-1
Balance June 30, 2013		$	27.9		$	19.5		$	0.6		$	23.6		$	71.6	$	32.3	$	103.9







		Fixed Maturities
(in millions)		Municipal			Corporate			Residential mortgage-backed, non-agency			Commercial mortgage-backed			Asset-backed		Total		Equity and Other		Total Assets
Six Months Ended
30-Jun-14
Balance January 1,2014		$	25.6		$	13.0		$	0.5		$	22.9		$	-	$	62.0	$	42.2	$	104.2
Transfers into Level 3			2.2			-			-			-			-		2.2		-		2.2
Transfers out of Level 3			-2.6			-			-			-			-		-2.6		-37.4		-40
Total gains (losses):																	-
Included in other comprehensive income-net appreciation on available-for-sale securities			0.6			0.2			-			0.7			-		1.5		-		1.5
Purchases and sales:																	-
Purchases			2.5			-			-			-			-		2.5		-		2.5
Sales			-1.5			-			-0.5			-1.1			-		-3.1		-		-3.1
Balance June 30, 2014		$	26.8		$	13.2		$	-		$	22.5		$	-	$	62.5	$	4.8	$	67.3

Six Months Ended
30-Jun-13
Balance January 1, 2013		$	19.4		$	26.4		$	0.7		$	26.7		$	1.5	$	74.7	$	28.0	$	102.7
Transfers into Level 3			9.7			0.2			-			-			-		9.9		-		9.9
Transfers out of Level 3			-			-2.2			-			-			-1.5		-3.7		-0.9		-4.6
Total gains (losses):
Included in earnings			-			0.4			-			-			-		0.4		-		0.4
Included in other comprehensive income-net (depreciation) appreciation on available-for-sale securities			-0.3			-1			-			-1.4			-		-2.7		5.2		2.5
Sales			-0.9			-4.3			-0.1			-1.7			-		-7		-		-7
Balance June 30, 2013		$	27.9		$	19.5		$	0.6		$	23.6		$	-	$	71.6	$	32.3	$	103.9
During the three and six months ended June 30, 2014 and 2013, the Company transferred fixed maturities between Level 2 and Level 3 primarily as a result of assessing the significance of unobservable inputs on the fair value measurement. There were no transfers between Level 1 and Level 2 during the three months or six months ended June 30, 2014 or 2013.
There were no Level 3 liabilities held by the Company for the six months ended June 30, 2014 and 2013. The following table summarizes gains and losses due to changes in fair value that were recorded in net income for Level 3 assets:



		Three Months Ended June 30						Six Months Ended June 30
		2014			2013			2014			2013
		Net Realized Investment						Net Realized Investment
(in millions)		Gains (Losses)						Gains (Losses)
Level 3 Assets:
Fixed maturities:
Corporate		$	-		$	-		$	-		$	0.4




The following table provides quantitative information about the significant unobservable inputs used by the Company in the fair value measurements of Level 3 assets. Where discounted cash flows were used in the valuation of fixed maturities, the internally-developed discount rate was adjusted by the significant unobservable inputs shown in the table. Valuations for securities based on broker quotes for which there was a lack of transparency as to inputs used to develop the valuations have been excluded.



						30-Jun-14					31-Dec-13
		Valuation		Significant			Fair		Range			Fair		Range
(in millions)		Technique		Unobservable Inputs			Value		(Wtd Average)			Value		(Wtd Average)
Fixed maturities:
Municipal		Discounted		Discount for:		$	26.8				$	25.6
		cash flow		Small issue size					0.6-4.0% (2.1%)					1.0-4.0% (2.3%)
				Above-market coupon					0.3-1.0% (0.4%)					0.3-1.0% (0.5%)
Corporate		Discounted		Discount for:			12.9					12.8
		cash flow		Above-market coupon					0.3-0.8% (0.6%)					0.3-0.8% (0.6%)
				Small issue size					0.3-1.0% (0.5%)					0.3-1.0% (0.5%)
Residential mortgage-backed,		Discounted		Discount for:			-					0.5
non-agency		cash flow		Small issue size					N/A					0.5% (0.5%)
Commercial mortgage-backed		Discounted		Discount for:			22.5					22.9
		cash flow		Above-market coupon					0.5-0.8% (0.5%)					0.5-0.8% (0.6%)
				Credit stress					0.5% (0.5%)					0.5% (0.5%)
				Small issue size					0.5% (0.5%)					0.5% (0.5%)
				Lease structure					0.3% (0.3%)					0.3% (0.3%)
Equity securities		Market		Net tangible asset			1.1					38.5
		comparables		market multiples					1.0X (1.0X)					1.3X (1.3X)
Other		Discounted		Discount rate			3.6		18.0% (18.0%)			3.6		18.0% (18.0%)
		cash flow
Significant increases (decreases) in any of the above inputs in isolation would result in a significantly lower (higher) fair value measurement. There were no interrelationships between these inputs which might magnify or mitigate the effect of changes in unobservable inputs on the fair value measurement.

Pension_and_Other_Postretireme

Pension and Other Postretirement Benefit Plans	6 Months Ended
Pension and Other Postretirement Benefit Plans	Jun. 30, 2014
Pension and Other Postretirement Benefit Plans [Abstract]	'
Pension and Other Postretirement Benefit Plans	'
	6. Pension and Other Postretirement Benefit Plans
	The components of net periodic pension cost for defined benefit pension and other postretirement benefit plans included in the Company’s results of operations are as follows:




		Three Months Ended June 30,
		2014		2013		2014		2013

	(in millions)	Pension Plans				Postretirement Plans
	Service cost - benefits earned during the period	$	0.3	$	0.5	$	-	$	0.1
	Interest cost		8.5		8.0		0.2		0.3
	Expected return on plan assets		-9.1		-8.9		-		-
	Recognized net actuarial loss		2.9		3.6		-		-
	Amortization of prior service cost		0.1		-		-0.5		-1
	Net settlement gain		-		-		-		-1.6
	Net periodic pension cost (benefit)	$	2.7	$	3.2	$	-0.3	$	-2.2

		Six Months Ended June 30,
		2014		2013		2014		2013

	(in millions)	Pension Plans				Postretirement Plans
	Service cost - benefits earned during the period	$	0.7	$	0.9	$	-	$	0.1
	Interest cost		16.9		15.9		0.4		0.8
	Expected return on plan assets		-18.3		-17.8		-		-
	Recognized net actuarial loss		5.8		7.3		-		0.1
	Amortization of prior service cost		0.1		-		-0.9		-1.9
	Net settlement gain		-		-		-		-1.6
	Net periodic pension cost (benefit)	$	5.2	$	6.3	$	-0.5	$	-2.5
	In May 2013, the Company settled and defeased the life insurance portion of its postretirement benefits by decreasing the level of death benefits and concurrently fully funding the remaining benefits through the purchase of life insurance policies for the plan beneficiaries from an unaffiliated life insurer, resulting in a net settlement gain.

Other_Comprehensive_Income

Other Comprehensive Income	6 Months Ended
Other Comprehensive Income	Jun. 30, 2014
Equity [Abstract]	'
Other Comprehensive Income	'
	7. Other Comprehensive Income
	The following table provides changes in other comprehensive income.


			Three Months Ended June 30,
			2014									2013
						Tax									Tax
						Benefit			Net of						Benefit		Net of
	(in millions)		Pre-Tax			(Expense)			Tax			Pre-Tax			(Expense)		Tax
	Unrealized gains (losses) on available-for-sale securities and
	derivative instruments:
	Unrealized gains (losses) arising during period (net of
	pre-tax, ceded unrealized gains (losses) of $0.7 million
	and ($0.8) million for the three months ended
	June 30, 2014 and 2013)		$	83.2			-29.2			54.0		$	-190		$	66.7	$	-123.3
	Less:
	Amount of realized gains from sales and other			-22.4			2.6			-19.8			-15			0.2		-14.8
	Portion of other-than-temporary impairment losses
	recognized in earnings			0.1			-			0.1			1.1			-0.4		0.7
	Net unrealized gains (losses)			60.9			-26.6			34.3			-203.9			66.5		-137.4
	Pension and postretirement benefits:
	Amortization of net actuarial loss and prior service cost
	recognized as net periodic benefit cost			2.5			-0.9			1.6			6.3			-2.2		4.1
	Cumulative foreign currency translation adjustment:
	Foreign currency translation recognized during
	the period			4.8			-1.7			3.1			-0.1			-		-0.1
	Other comprehensive income (loss)		$	68.2		$	-29.2		$	39.0		$	-197.7		$	64.3	$	-133.4


			Six Months Ended June 30,
			2014									2013
						Tax									Tax
						Benefit			Net of						Benefit		Net of
	(in millions)		Pre-Tax			(Expense)			Tax			Pre-Tax			(Expense)		Tax
	Unrealized gains (losses) on available-for-sale securities and
	derivative instruments:
	Unrealized gains (losses) arising during period (net of
	pre-tax, ceded unrealized gains (losses) of $1.2 million
	and ($0.8) million for the six months ended June 30, 2014
	and 2013)		$	166.5		$	-55.3		$	111.2		$	-165		$	57.9	$	-107.1
	Less:
	Amount of realized gains from sales and other			-26.7			-1.5			-28.2			-23.8			-2.1		-25.9
	Portion of other-than-temporary impairment losses
	recognized in earnings			0.1			-			0.1			1.6			-0.6		1.0
	Net unrealized gains (losses)			139.9			-56.8			83.1			-187.2			55.2		-132
	Pension and postretirement benefits:
	Amortization of net actuarial loss and prior service cost
	recognized as net periodic benefit cost			5.2			-1.8			3.4			9.2			-3.2		6.0
	Cumulative foreign currency translation adjustment:
	Foreign currency translation recognized during
	the period			4.7			-1.7			3.0			-15.5			5.4		-10.1
	Other comprehensive income (loss)		$	149.8		$	-60.3		$	89.5		$	-193.5		$	57.4	$	-136.1





	Reclassifications out of accumulated other comprehensive income were as follows:




			Three Months Ended						Six Months Ended
			June 30,					June 30,

(in millions)			2014		2013			2014			2013

		Amount Reclassified from
Details about Accumulated Other		Accumulated Other												Affected Line Item in the Statement
Comprehensive Income Components		Comprehensive Income												Where Net Income is Presented
Unrealized gains on available-for-sale
securities and derivative instruments		$	22.4		$	15.1		$	26.7		$	23.8		Net realized gains from sales and other
														Net other-than-temporary impairment
														(losses) on investments recognized
			-0.1			-1.1			-0.1			-1.6		in earnings
Other			-			-0.1			-			-
			22.3			13.9			26.6			22.2		Total before tax
			-2.6			0.2			1.5			2.7		Tax (expense) benefit
			19.7			14.1			28.1			24.9		Net of tax
Amortization of defined benefit pension														Loss adjustment expenses and other
and postretirement plans			-2.5			-6.3			-5.2			-9.2		operating expenses
			0.9			2.2			1.8			3.2		Tax benefit
			-1.6			-4.1			-3.4			-6		Net of tax
Total reclassifications for the period		$	18.1		$	10.0		$	24.7		$	18.9		Net of tax
The amount reclassified from accumulated other comprehensive income for the pension and postretirement benefits was allocated approximately 40% to loss adjustment expenses and 60% to other operating expenses for the six months ended June 30, 2014 and 2013.

Segment_Information

Segment Information	6 Months Ended
Segment Information	Jun. 30, 2014
Segment Information [Abstract]	'
Segment Information	'




	8. Segment Information
	The Company’s primary business operations include insurance products and services provided through four operating segments. The domestic operating segments are Commercial Lines, Personal Lines and Other, and the Company’s international operating segment is Chaucer. Commercial Lines includes commercial multiple peril, commercial automobile, workers’ compensation, and other commercial coverages, such as specialty program business, inland marine, management and professional liability and surety. Personal Lines includes personal automobile, homeowners and other personal coverages. Chaucer includes marine and aviation, energy, property, U.K. motor, and casualty and other coverages (which includes international liability, specialist coverages, and syndicate participations). Included in Other are Opus Investment Management, Inc., which markets investment management services to institutions, pension funds and other organizations; earnings on holding company assets; and, a voluntary pools business which is in run-off. The separate financial information is presented consistent with the way results are regularly evaluated by the chief operating decision maker in deciding how to allocate resources and in assessing performance.
	The Company reports interest expense related to debt separately from the earnings of its operating segments. This consists of interest on the Company’s senior debentures, subordinated debentures, collateralized borrowings with the Federal Home Loan Bank of Boston, and letter of credit facility. Management evaluates the results of the aforementioned segments based on operating income (loss) before taxes which also excludes interest expense on debt. Operating income (loss) before taxes excludes certain items which are included in net income (loss), such as net realized investment gains and losses (including gains and losses on certain derivative instruments). Such gains and losses are excluded since they are determined by interest rates, financial markets and the timing of sales. Also, operating income (loss) before taxes excludes net gains and losses on disposals of businesses, gains and losses related to the repayment of debt, discontinued operations, costs to acquire businesses, restructuring costs, extraordinary items, the cumulative effect of accounting changes and certain other items. Although the items excluded from operating income (loss) before taxes may be important components in understanding and assessing the Company’s overall financial performance, management believes that the presentation of operating income (loss) before taxes enhances an investor’s understanding of the Company’s results of operations by highlighting net income (loss) attributable to the core operations of the business. However, operating income (loss) before taxes should not be construed as a substitute for income (loss) before income taxes and operating income (loss) should not be construed as a substitute for net income (loss).




	Summarized below is financial information with respect to the Company’s business segments.




				Three Months Ended					Six Months Ended
				June 30,					June 30,
	(in millions)			2014			2013		2014		2013
	Operating revenues:
	Commercial Lines		$	556.9		$	523.7	$	1,108.9	$	1,038.4
	Personal Lines			371.4			388.9		742.4		780.0
	Chaucer			320.6			253.5		635.1		517.4
	Other			1.9			2.8		3.9		5.3
	Total			1,250.8			1,168.9		2,490.3		2,341.1
	Net realized investment gains			22.2			13.7		26.6		21.8
	Total revenues		$	1,273.0		$	1,182.6	$	2,516.9	$	2,362.9
	Operating income (loss) before income taxes:
	Commercial Lines:
	GAAP underwriting gain (loss)		$	7.3		$	-9.5	$	-14	$	-12.6
	Net investment income			37.2			36.0		74.5		72.1
	Other expense			-0.3			-0.3		-0.2		-0.3
	Commercial Lines operating income			44.2			26.2		60.3		59.2
	Personal Lines:
	GAAP underwriting income (loss)			3.6			-0.3		5.7		9.8
	Net investment income			18.0			19.1		35.9		38.1
	Other income			1.1			1.1		2.7		2.5
	Personal Lines operating income			22.7			19.9		44.3		50.4
	Chaucer:
	GAAP underwriting income			24.3			24.7		60.8		57.7
	Net investment income			10.7			10.7		21.2		21.2
	Other income (expense)			3.1			1.5		5.3		-1.1
	Chaucer operating income			38.1			36.9		87.3		77.8
	Other:
	GAAP underwriting loss			-0.9			-1		-1.4		-2.1
	Net investment income			1.1			2.1		2.4		3.8
	Other net expenses			-3			-3		-5.7		-5.8
	Other operating loss			-2.8			-1.9		-4.7		-4.1
	Operating income before interest expense and income taxes			102.2			81.1		187.2		183.3
	Interest on debt			-16.3			-17.4		-32.6		-32.1
	Operating income before income taxes			85.9			63.7		154.6		151.2
	Non-operating income items:
	Net realized investment gains			22.2			13.7		26.6		21.8
	Net loss from repayment of debt			-			-11.3		-		-19.1
	Net (costs) benefit related to acquired businesses			-0.2			-0.2		-1.1		0.2
	Net foreign exchange (losses) gains			-0.2			-		-0.3		0.7
	Income before income taxes		$	107.7		$	65.9	$	179.8	$	154.8
	The Company recognized $5.1 million in net foreign currency transaction gains in the Statements of Income during the three months ended June 30, 2014 compared to $5.6 million in net foreign currency losses during the three months ended June 30, 2013. The Company recognized $5.8 million in net foreign currency transaction gains in the Statements of Income during the six months ended June 30, 2014 compared to $7.7 million in net foreign currency losses during the six months ended June 30, 2013.





The following table provides identifiable assets for the Company’s business segments and discontinued operations:




		June 30,			December 31,
		2014			2013

(in millions)		Identifiable Assets
U.S. Companies		$	9,176.9		$	8,962.6
Chaucer			4,672.9			4,301.2
Discontinued operations			115.0			114.9
Total		$	13,964.8		$	13,378.7
The Company reviews the assets of its U.S. Companies collectively and does not allocate them between the Commercial Lines, Personal Lines and Other segments.

Stockbased_Compensation

Stock-based Compensation	6 Months Ended
Stock-based Compensation	Jun. 30, 2014
Stock-based Compensation [Abstract]	'
Stock-based Compensation	'
	9. Stock-based Compensation

	On May 20, 2014 the shareholders approved the adoption of The Hanover Insurance Group 2014 Long-Term Incentive Plan (the “2014 Stock Plan”). With respect to new share-based award issuances, the 2014 Stock Plan replaced The Hanover Insurance Group, Inc. 2006 Long-Term Incentive Plan (the “2006 Stock Plan”) and provided authorization for 6,100,000 shares in a new share pool plus any shares from the 2006 Stock Plan that may become available as a result of the cash settlement, forfeiture, expiration or cancellation of such awards. The 2014 Stock Plan provides for the granting of the same types of awards as the 2006 Stock Plan, which includes stock options and SARS, restricted and unrestricted stock, stock units, performance based stock awards and cash awards. In accordance with the 2014 Stock Plan, the issuance of one share of common stock in the form of an option or SAR will reduce the share pool by one share, whereas the issuance of one share of common stock for the other types of stock awards provided by the plan will reduce the pool by 3.8 shares. As of June 30, 2014, there were 6,096,349 shares available for grants under the 2014 Stock Plan.

	Additionally, on May 20, 2014, the shareholders approved The Hanover Insurance Group 2014 Employee Stock Purchase plan (the “ESPP Plan”) and the Chaucer Share Incentive Plan (the “SIP Plan”), authorizing the issuance of 2,500,000 and 750,000 shares, respectively, under such plans. As of June 30, 2014, 23,105 shares and 2,737 shares have been issued under the ESPP Plan and the SIP Plan, respectively.
	Compensation cost and the related tax benefits were as follows:


		Three Months Ended						Six Months Ended
		June 30,						June 30,
	(in millions)	2014			2013			2014			2013
	Stock-based compensation expense	$	3.8		$	2.1		$	7.3		$	5.7
	Tax benefit		-1.4			-0.7			-2.6			-2
	Stock-based compensation expense, net of taxes	$	2.4		$	1.4		$	4.7		$	3.7
	Stock Options
	Information on the Company’s stock option plans is summarized below.


		Six Months Ended June 30,
		2014					2013
	(in whole shares and dollars)	Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price
	Outstanding, beginning of period	2,049,173		$	41.18		2,892,882		$	38.28
	Granted	683,200			58.02		537,300			42.51
	Exercised	-243,491			38.66		-798,790			32.84
	Forfeited or cancelled	-34,085			41.84		-164,500			41.74
	Outstanding, end of period	2,454,797			46.10		2,466,892			40.74





	Restricted Stock Units
	The following tables summarize activity information about employee restricted stock units:



		Six Months Ended June 30,
		2014					2013
	(in whole shares and dollars)	Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value
	Time-based restricted stock units:
	Outstanding, beginning of period	525,980		$	41.20		750,837		$	40.15
	Granted	94,240			58.02		130,912			42.80
	Vested	-202,006			42.09		-259,440			39.60
	Forfeited	-9,300			40.73		-37,257			40.49
	Outstanding, end of period	408,914			44.65		585,052			40.96

	Performance-based and market-based restricted stock units:
	Outstanding, beginning of period	184,626		$	40.42		132,775		$	39.97
	Granted	60,338			55.73		79,850			41.67
	Vested	-22,826			44.78		-			-
	Forfeited	-3,800			37.90		-22,700			40.83
	Outstanding, end of period	218,338			44.24		189,925			40.58
	Performance based restricted stock units are based upon the achievement of the performance metric at 100%. These units have the potential to range from 0% to 200% of the shares disclosed, which varies based on grant year and individual participation level. Increases above the 100% target level are reflected as granted in the period in which performance-based stock unit goals are achieved. Decreases below the 100% target level are reflected as forfeited. Included in the amounts granted above for the performance-based restricted stock units were 1,013 shares related to awards that a performance metric in excess of 100% was achieved. These awards vested in the first quarter of 2014.
	In the first six months of 2014 and 2013, the Company granted market-based awards totaling 56,625 and 76,175, respectively, to certain members of senior management, which are included in the table above as performance and market-based restricted stock activity. The vesting of these stock units is based on the relative total shareholder return (“TSR”) of the Company. This metric is generally based on relative TSR for a three-year period, as compared to a Property and Casualty Index of peer companies. The fair value of market based awards was estimated at the date of grant using a valuation model. These units have the potential to range from 0% to 150% of the shares disclosed. Included in the amount granted above were 1,875 shares related to market-based awards that achieved a payout in excess of 100%. These awards vested in the first quarter of 2014.

Earnings_Per_Share_and_Shareho

Earnings Per Share and Shareholders' Equity Transactions	6 Months Ended
Earnings Per Share and Shareholders' Equity Transactions	Jun. 30, 2014
Earnings Per Share and Shareholdersb Equity Transactions [Abstract]	'
Earnings Per Share and Shareholders' Equity Transactions	'
	10. Earnings Per Share and Shareholders’ Equity Transactions
	The following table provides weighted average share information used in the calculation of the Company’s basic and diluted earnings per share:



		Three Months Ended				Six Months Ended
		June 30,				June 30,

	(in millions, except per share data)		2014		2013		2014		2013
	Basic shares used in the calculation of earnings per share		44.1		44.0		44.0		44.3
	Dilutive effect of securities:
	Employee stock options		0.4		0.4		0.4		0.3
	Non-vested stock grants		0.4		0.4		0.4		0.4
	Diluted shares used in the calculation of earnings per share		44.9		44.8		44.8		45.0
	Per share effect of dilutive securities on income from continuing operations	$	-0.03	$	-0.02	$	-0.06	$	-0.05
	Per share effect of dilutive securities on income from net income	$	-0.04	$	-0.02	$	-0.06	$	-0.04
	Diluted earnings per share for the three months ended June 30, 2014 excludes 0.7 million of common shares issuable under the Company’s stock compensation plans, because their effect would be antidilutive. All of the common shares issuable under the Company’s stock compensation plan were included in the diluted earnings per share for the three months ended June 30, 2013. Diluted earnings per share for both the six months ended June 30, 2014 and 2013 excludes 0.7 million of common shares issuable under the Company’s stock compensation plans, because their effect would be antidilutive.
	Since October 2007 and through June 2014, the Company’s Board of Directors has authorized aggregate repurchases of the Company’s common stock of up to $600 million. As of June 30, 2014, the Company has $130.3 million available for repurchases under these repurchase authorizations. Repurchases may be executed using open market purchases, privately negotiated transactions, accelerated repurchase programs or other transactions. The Company is not required to purchase any specific number of shares or to make purchases by any certain date under this program. During the first six months of 2014, the Company purchased 0.1 million shares of the Company’s common stock at a cost of $6.7 million.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2014
Commitments and Contingencies [Abstract]	'
Commitments and Contingencies	'
	11. Commitments and Contingencies
	Legal Proceedings
	Durand Litigation
	On March 12, 2007, a putative class action suit captioned Jennifer A. Durand v. The Hanover Insurance Group, Inc., and The Allmerica Financial Cash Balance Pension Plan was filed in the United States District Court for the Western District of Kentucky. The named plaintiff, a former employee who received a lump sum distribution from the Company’s Cash Balance Plan (the “Plan”) at or about the time of her termination, claims that she and others similarly situated did not receive the appropriate lump sum distribution because in computing the lump sum, the Company and the Plan understated the accrued benefit in the calculation. The plaintiff claims that the Plan underpaid her distributions and those of similarly situated participants by failing to pay an additional so-called “whipsaw” amount reflecting the present value of an estimate of future interest credits from the date of the lump sum distribution to each participant’s retirement age of 65.
	The plaintiff filed an Amended Complaint adding two new named plaintiffs and additional claims on December 11, 2009. In response, the Company filed a Motion to Dismiss on January 30, 2010. In addition to the pending claim challenging the calculation of lump sum distributions, the Amended Complaint included: (a) a claim that the Plan failed to calculate participants’ account balances and lump sum payments properly because interest credits were based solely upon the performance of each participant’s selection from among various hypothetical investment options (as the Plan provided) rather than crediting the greater of that performance or the 30 year Treasury rate; (b) a claim that the 2004 Plan amendment, which changed interest crediting for all participants from the performance of participant’s investment selections to the 30 year Treasury rate, reduced benefits in violation of the Employee Retirement Income Security Act of 1974 (“ERISA”) for participants who had account balances as of the amendment date by not continuing to provide them performance-based interest crediting on those balances; and (c) claims against the Company for breach of fiduciary duty and ERISA notice requirements arising from the various interest crediting and lump sum distribution matters of which plaintiffs complain. On March 31, 2011, the District Court granted the Company and the Plan’s Motion to Dismiss on statute of limitations grounds the additional claims set forth in (a) and (b) above, however, in response to a motion for reconsideration, the Court allowed the new breach of fiduciary duty claim to stand, but only as to plaintiffs’ “whipsaw” claim that remained in the case. On June 22, 2012, the Company and the Plan filed a Partial Motion for Summary Judgment to dismiss the “whipsaw” claim of one of the named plaintiffs who received his lump sum distribution after December 31, 2003. On October 2, 2013, the Court granted the Company and the Plan’s Partial Motion for Summary Judgment and dismissed with prejudice the “whipsaw” claim of the named plaintiff who received a lump sum distribution after December 31, 2003 and the similar claims of the putative class members he sought to represent. On December 17, 2013, the Court entered an order certifying a class to bring “whipsaw” and related breach of fiduciary duty claims consisting of all persons who received a lump sum distribution between March 1, 1997 and December 31, 2003, and a subclass to bring such claims consisting of all persons who received lump sum distributions between March 1, 1997 and March 12, 2002. On December 17, 2013, the Court also granted plaintiffs’ motion for entry of a final order allowing an immediate appeal by the two named plaintiffs added in the Amended Complaint of their dismissed claims that the 2004 Plan amendment reduced benefits in violation of ERISA, and for one of them, that his post-2003 lump sum distribution should have been greater. On January 14, 2014, the Company filed a Motion to Alter or Amend the Court’s December 17, 2013 Order requesting that the Court reverse its order making the dismissed claims final and appealable or, in the alternative, stay merits discovery on the claims remaining in the district court pending resolution of the dismissed plaintiffs’ appeal. The Court denied this motion on April 30, 2014.
	At this time, the Company is unable to provide a reasonable estimate of the potential range of ultimate liability if the outcome of the suit is unfavorable. The extent to which any of the plaintiffs’ multiple theories of liability, some of which are overlapping and others of which are quite complex and novel, are accepted and upheld on appeal will significantly affect the Plan’s or the Company’s potential liability. The statute of limitations applicable to the class has not yet been finally determined and the extent of potential liability, if any, will depend on this final determination. In addition, assuming for these purposes that the plaintiffs prevail with respect to claims that benefits accrued or payable under the Plan were understated, then there are numerous possible theories and other variables upon which any revised calculation of benefits as requested under plaintiffs’ claims could be based. Any adverse judgment in this case against the Plan would be expected to create a liability for the Plan, with resulting effects on the Plan’s assets available to pay benefits. The Company’s future required funding of the Plan could also be impacted by such a liability.
	Other Matters
	The Company has been named a defendant in various other legal proceedings arising in the normal course of business. In addition, the Company is involved, from time to time, in examinations, investigations and proceedings by governmental and self-regulatory agencies. The potential outcome of any such action or regulatory proceedings in which the Company has been named a defendant or the subject of an inquiry or investigation, and its ultimate liability, if any, from such action or regulatory proceedings, is difficult to predict at this time. The ultimate resolutions of such proceedings are not expected to have a material effect on its financial position, although they could have a material effect on the results of operations for a particular quarter or annual period.
	Residual Markets
	The Company is required to participate in residual markets in various states, which generally pertain to high risk insureds, disrupted markets or lines of business or geographic areas where rates are regarded as excessive. The results of the residual markets are not subject to the predictability associated with the Company’s own managed business, and are significant to both the personal and commercial automobile lines of business, the workers’ compensation line of business, and the homeowners line of business.

Subsequent_Events

Subsequent Events	6 Months Ended
Subsequent Events	Jun. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	12. Subsequent Events
	There were no subsequent events requiring adjustment to the financial statements and no additional disclosures required in the notes to the interim consolidated financial statements.

Investments_Tables

Investments (Tables)	6 Months Ended
Investments (Tables)	Jun. 30, 2014
Investments [Abstract]	'
Schedule of Available-for-sale Securities Reconciliation	'


		30-Jun-14
		Amortized		Gross		Gross				OTTI
		Cost or		Unrealized		Unrealized				Unrealized
	(in millions)	Cost		Gains		Losses		Fair Value		Losses
	Fixed maturities:
	U.S. Treasury and government agencies	$	403.5	$	6.0	$	6.3	$	403.2	$	-
	Foreign government		319.7		2.6		1.3		321.0		-
	Municipal		1,080.4		59.5		6.4		1,133.5		-
	Corporate		3,718.3		205.4		15.0		3,908.7		7.4
	Residential mortgage-backed		697.3		22.1		5.8		713.6		0.4
	Commercial mortgage-backed		395.1		12.5		1.5		406.1		-
	Asset-backed		170.8		1.7		0.1		172.4		-
	Total fixed maturities	$	6,785.1	$	309.8	$	36.4	$	7,058.5	$	7.8
	Equity securities	$	446.4	$	84.9	$	0.8	$	530.5	$	-








		31-Dec-13
		Amortized		Gross		Gross				OTTI
		Cost or		Unrealized		Unrealized				Unrealized
	(in millions)	Cost		Gains		Losses		Fair Value		Losses
	Fixed maturities:
	U.S. Treasury and government agencies	$	417.5	$	3.3	$	14.2	$	406.6	$	-
	Foreign government		304.5		2.1		1.6		305.0		-
	Municipal		1,108.0		37.4		19.1		1,126.3		-
	Corporate		3,690.2		171.5		37.5		3,824.2		8.6
	Residential mortgage-backed		722.8		20.1		14.1		728.8		1.6
	Commercial mortgage-backed		405.9		10.5		4.8		411.6		-
	Asset-backed		166.3		2.0		0.2		168.1		-
	Total fixed maturities	$	6,815.2	$	246.9	$	91.5	$	6,970.6	$	10.2
	Equity securities	$	366.5	$	66.9	$	3.2	$	430.2	$	-



Investments Classified by Contractual Maturity Date	'


		30-Jun-14
		Amortized		Fair
	(in millions)	Cost		Value
	Due in one year or less	$	400.6	$	404.8
	Due after one year through five years		2,329.2		2,437.4
	Due after five years through ten years		2,116.5		2,215.1
	Due after ten years		675.6		709.1
			5,521.9		5,766.4
	Mortgage-backed and asset-backed securities		1,263.2		1,292.1
	Total fixed maturities	$	6,785.1	$	7,058.5



Schedule of Unrealized Loss on Investments	'




		30-Jun-14
		12 months or less				Greater than 12 months				Total
		Gross				Gross				Gross
		Unrealized		Fair		Unrealized		Fair		Unrealized		Fair
	(in millions)	Losses		Value		Losses		Value		Losses		Value
	Fixed maturities:
	Investment grade:
	U.S. Treasury and government agencies	$	-	$	6.4	$	6.3	$	152.0	$	6.3	$	158.4
	Foreign governments		0.8		100.7		0.5		56.1		1.3		156.8
	Municipal		0.4		53.3		5.7		158.9		6.1		212.2
	Corporate		2.6		198.4		10.1		259.7		12.7		458.1
	Residential mortgage-backed		0.5		39.7		5.3		135.5		5.8		175.2
	Commercial mortgage-backed		0.1		31.3		1.4		65.4		1.5		96.7
	Asset-backed		-		10.7		0.1		14.2		0.1		24.9
	Total investment grade		4.4		440.5		29.4		841.8		33.8		1,282.3
	Below investment grade:
	Municipal		0.3		4.4		-		-		0.3		4.4
	Corporate		0.5		16.2		1.8		25.0		2.3		41.2
	Total below investment grade		0.8		20.6		1.8		25.0		2.6		45.6
	Total fixed maturities		5.2		461.1		31.2		866.8		36.4		1,327.9
	Equity securities		-		10.0		0.8		3.4		0.8		13.4
	Total	$	5.2	$	471.1	$	32.0	$	870.2	$	37.2	$	1,341.3





		31-Dec-13
		12 months or less				Greater than 12 months				Total
		Gross				Gross				Gross
		Unrealized		Fair		Unrealized		Fair		Unrealized		Fair
	(in millions)	Losses		Value		Losses		Value		Losses		Value
	Fixed maturities:
	Investment grade:
	U.S. Treasury and government agencies	$	12.3	$	247.9	$	1.9	$	18.8	$	14.2	$	266.7
	Foreign governments		1.5		129.0		0.1		17.3		1.6		146.3
	Municipal		14.8		345.3		4.3		39.9		19.1		385.2
	Corporate		21.4		872.7		11.6		87.7		33.0		960.4
	Residential mortgage-backed		10.3		321.1		3.4		29.5		13.7		350.6
	Commercial mortgage-backed		4.2		155.4		0.6		10.2		4.8		165.6
	Asset-backed		0.2		31.0		-		0.3		0.2		31.3
	Total investment grade		64.7		2,102.4		21.9		203.7		86.6		2,306.1
	Below investment grade:
	Corporate		2.9		71.9		1.6		21.4		4.5		93.3
	Residential mortgage-backed		0.1		2.0		0.3		1.5		0.4		3.5
	Total below investment grade		3.0		73.9		1.9		22.9		4.9		96.8
	Total fixed maturities		67.7		2,176.3		23.8		226.6		91.5		2,402.9
	Equity securities		2.8		45.2		0.4		0.7		3.2		45.9
	Total	$	70.5	$	2,221.5	$	24.2	$	227.3	$	94.7	$	2,448.8



Schedule of Realized Gain (Loss)	'


		Three Months Ended June 30,
		2014						2013
		Proceeds from		Gross		Gross		Proceeds from		Gross		Gross
	(in millions)	Sales		Gains		Losses		Sales		Gains		Losses
	Fixed maturities	$	70.5	$	1.1	$	1.1	$	148.5	$	3.0	$	0.4
	Equity securities	$	60.0	$	22.2	$	0.7	$	44.4	$	10.4	$	0.3





		Six Months Ended June 30,
		2014						2013
		Proceeds from		Gross		Gross		Proceeds from		Gross		Gross
	(in millions)	Sales		Gains		Losses		Sales		Gains		Losses
	Fixed maturities	$	208.1	$	3.3	$	2.3	$	285.7	$	4.6	$	1.0
	Equity securities	$	72.4	$	24.1	$	0.8	$	78.9	$	17.0	$	0.3



Rollforward of Cumulative Amounts Related to Credit Loss Portion of OTTI Losses	'


		Three Months Ended June 30,				Six Months Ended June 30,
	(in millions)	2014		2013		2014		2013
	Credit losses at beginning of period	$	5.3	$	8.6	$	7.8	$	8.6
	Credit losses for which an OTTI was not		-		0.1		-		0.3
	previously recognized		-		0.1		-		0.3
	Additional credit losses on securities for which an
	OTTI was previously recognized		-		-		-		0.2
	Reductions for securities sold, matured or called		-0.6		-1.4		-3.1		-1.8
	Reductions for securities reclassified as intended to sell		-0.4		-		-0.4		-
	Credit losses at the end of period	$	4.3	$	7.3	$	4.3	$	7.3

Fair_Value_Tables

Fair Value (Tables)	6 Months Ended
Fair Value (Tables)	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value of Financial Instruments	'


		30-Jun-14						31-Dec-13
		Carrying			Fair			Carrying		Fair
	(in millions)	Value			Value			Value		Value
	Financial Assets
	Cash and cash equivalents	$	606.2		$	606.2		$	486.2	$	486.2
	Fixed maturities		7,058.5			7,058.5			6,970.6		6,970.6
	Equity securities		530.5			530.5			430.2		430.2
	Other investments		218.4			220.9			173.1		173.7
	Total financial assets	$	8,413.6		$	8,416.1		$	8,060.1	$	8,060.7
	Financial Liabilities
	Debt	$	903.9		$	1,030.7		$	903.9	$	961.7


Fair Value, Assets Measured on Recurring Basis	'


		30-Jun-14
	(in millions)		Total			Level 1			Level 2		Level 3
	Fixed maturities:
	U.S. Treasury and government agencies	$	403.2		$	160.5		$	242.7	$	-
	Foreign government		321.0			42.8			278.2		-
	Municipal		1,133.5			-			1,106.7		26.8
	Corporate		3,908.7			-			3,895.5		13.2
	Residential mortgage-backed, U.S. agency backed		586.2			-			586.2		-
	Residential mortgage-backed, non-agency		127.4			-			127.4		-
	Commercial mortgage-backed		406.1			-			383.6		22.5
	Asset-backed		172.4			-			172.4		-
	Total fixed maturities		7,058.5			203.3			6,792.7		62.5
	Equity securities		521.2			520.0			-		1.2
	Other investments		138.5			-			134.9		3.6
	Total investment assets at fair value	$	7,718.2		$	723.3		$	6,927.6	$	67.3




		31-Dec-13
	(in millions)		Total			Level 1			Level 2		Level 3
	Fixed maturities:
	U.S. Treasury and government agencies	$	406.6		$	167.2		$	239.4	$	-
	Foreign government		305.0			45.6			259.4		-
	Municipal		1,126.3			-			1,100.7		25.6
	Corporate		3,824.2			-			3,811.2		13.0
	Residential mortgage-backed, U.S. agency backed		573.2			-			573.2		-
	Residential mortgage-backed, non-agency		155.6			-			155.1		0.5
	Commercial mortgage-backed		411.6			-			388.7		22.9
	Asset-backed		168.1			-			168.1		-
	Total fixed maturities		6,970.6			212.8			6,695.8		62.0
	Equity securities		420.9			382.3			-		38.6
	Other investments		153.2			-			149.6		3.6
	Total investment assets at fair value	$	7,544.7		$	595.1		$	6,845.4	$	104.2


Estimated Fair Values of Financial Instruments Not Carried at Fair Value	'



			30-Jun-14
	(in millions)		Total			Level 1			Level 2		Level 3
	Assets:
	Cash and cash equivalents	$	606.2		$	606.2		$	-	$	-
	Equity securities		9.3			-			9.3		-
	Other investments		82.4			-			58.6		23.8
	Liabilities:
	Debt	$	1,030.7		$	-		$	1,030.7	$	-


			31-Dec-13
	(in millions)		Total			Level 1			Level 2		Level 3
	Assets:
	Cash and cash equivalents	$	486.2		$	486.2		$	-	$	-
	Equity securities		9.3			-			9.3		-
	Other investments		20.5			-			2.7		17.8
	Liabilities:
	Debt	$	961.7		$	-		$	961.7	$	-


Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)	'



			Fixed Maturities
	(in millions)	Municipal			Corporate			Residential mortgage-backed, non-agency		Commercial mortgage-backed		Total		Equity and Other		Total Assets
	Three Months Ended
	30-Jun-14
	Balance April 1, 2014	$	29.6		$	13.2		$	-	$	22.5	$	65.3	$	4.8	$	70.1
	Transfers out of Level 3		-2.6			-			-		-		-2.6		-		-2.6
	Total gains:												-
	Included in other comprehensive income - net appreciation on available-for-sale securities		0.3			-			-		0.4		0.7		-		0.7
	Sales		-0.5			-			-		-0.4		-0.9		-		-0.9
	Balance June 30, 2014	$	26.8		$	13.2		$	-	$	22.5	$	62.5	$	4.8	$	67.3

	Three Months Ended
	30-Jun-13
	Balance April 1, 2013	$	28.8		$	22.8		$	0.6	$	24.8	$	77.0	$	28.6	$	105.6
	Transfers out of Level 3		-			-2.2			-		-		-2.2		-		-2.2
	Total gains (losses):
	Included in other comprehensive income - net (depreciation) appreciation on available-for-sale securities		-0.4			-0.9			-		-0.9		-2.2		3.7		1.5
	Sales		-0.5			-0.2			-		-0.3		-1		-		-1
	Balance June 30, 2013	$	27.9		$	19.5		$	0.6	$	23.6	$	71.6	$	32.3	$	103.9







		Fixed Maturities
	(in millions)	Municipal			Corporate			Residential mortgage-backed, non-agency		Commercial mortgage-backed		Asset-backed		Total		Equity and Other		Total Assets
	Six Months Ended
	30-Jun-14
	Balance January 1,2014	$	25.6		$	13.0		$	0.5	$	22.9	$	-	$	62.0	$	42.2	$	104.2
	Transfers into Level 3		2.2			-			-		-		-		2.2		-		2.2
	Transfers out of Level 3		-2.6			-			-		-		-		-2.6		-37.4		-40
	Total gains (losses):														-
	Included in other comprehensive income-net appreciation on available-for-sale securities		0.6			0.2			-		0.7		-		1.5		-		1.5
	Purchases and sales:														-
	Purchases		2.5			-			-		-		-		2.5		-		2.5
	Sales		-1.5			-			-0.5		-1.1		-		-3.1		-		-3.1
	Balance June 30, 2014	$	26.8		$	13.2		$	-	$	22.5	$	-	$	62.5	$	4.8	$	67.3

	Six Months Ended
	30-Jun-13
	Balance January 1, 2013	$	19.4		$	26.4		$	0.7	$	26.7	$	1.5	$	74.7	$	28.0	$	102.7
	Transfers into Level 3		9.7			0.2			-		-		-		9.9		-		9.9
	Transfers out of Level 3		-			-2.2			-		-		-1.5		-3.7		-0.9		-4.6
	Total gains (losses):
	Included in earnings		-			0.4			-		-		-		0.4		-		0.4
	Included in other comprehensive income-net (depreciation) appreciation on available-for-sale securities		-0.3			-1			-		-1.4		-		-2.7		5.2		2.5
	Sales		-0.9			-4.3			-0.1		-1.7		-		-7		-		-7
	Balance June 30, 2013	$	27.9		$	19.5		$	0.6	$	23.6	$	-	$	71.6	$	32.3	$	103.9


Summary Gains and Losses due to Changes in Fair Value Recorded in Income for Level Three Assets	'


		Three Months Ended June 30						Six Months Ended June 30
		2014			2013			2014		2013
		Net Realized Investment						Net Realized Investment
	(in millions)	Gains (Losses)						Gains (Losses)
	Level 3 Assets:
	Fixed maturities:
	Corporate	$	-		$	-		$	-	$	0.4


Schedule of Additional Information About Significant Unobservable Inputs Used in Fair Valuations of Level 3	'


						30-Jun-14				31-Dec-13
		Valuation		Significant			Fair		Range		Fair	Range
	(in millions)	Technique		Unobservable Inputs			Value		(Wtd Average)		Value	(Wtd Average)
	Fixed maturities:
	Municipal	Discounted		Discount for:		$	26.8			$	25.6
		cash flow		Small issue size					0.6-4.0% (2.1%)			1.0-4.0% (2.3%)
				Above-market coupon					0.3-1.0% (0.4%)			0.3-1.0% (0.5%)
	Corporate	Discounted		Discount for:			12.9				12.8
		cash flow		Above-market coupon					0.3-0.8% (0.6%)			0.3-0.8% (0.6%)
				Small issue size					0.3-1.0% (0.5%)			0.3-1.0% (0.5%)
	Residential mortgage-backed,	Discounted		Discount for:			-				0.5
	non-agency	cash flow		Small issue size					N/A			0.5% (0.5%)
	Commercial mortgage-backed	Discounted		Discount for:			22.5				22.9
		cash flow		Above-market coupon					0.5-0.8% (0.5%)			0.5-0.8% (0.6%)
				Credit stress					0.5% (0.5%)			0.5% (0.5%)
				Small issue size					0.5% (0.5%)			0.5% (0.5%)
				Lease structure					0.3% (0.3%)			0.3% (0.3%)
	Equity securities	Market		Net tangible asset			1.1				38.5
		comparables		market multiples					1.0X (1.0X)			1.3X (1.3X)
	Other	Discounted		Discount rate			3.6		18.0% (18.0%)		3.6	18.0% (18.0%)
		cash flow

Pension_and_Other_Postretireme1

Pension and Other Postretirement Benefit Plans (Tables)	6 Months Ended
Pension and Other Postretirement Benefit Plans (Tables)	Jun. 30, 2014
Pension and Other Postretirement Benefit Plans [Abstract]	'
Components of Net Periodic Pension Cost	'


		Three Months Ended June 30,
		2014		2013		2014		2013

	(in millions)	Pension Plans				Postretirement Plans
	Service cost - benefits earned during the period	$	0.3	$	0.5	$	-	$	0.1
	Interest cost		8.5		8.0		0.2		0.3
	Expected return on plan assets		-9.1		-8.9		-		-
	Recognized net actuarial loss		2.9		3.6		-		-
	Amortization of prior service cost		0.1		-		-0.5		-1
	Net settlement gain		-		-		-		-1.6
	Net periodic pension cost (benefit)	$	2.7	$	3.2	$	-0.3	$	-2.2

		Six Months Ended June 30,
		2014		2013		2014		2013

	(in millions)	Pension Plans				Postretirement Plans
	Service cost - benefits earned during the period	$	0.7	$	0.9	$	-	$	0.1
	Interest cost		16.9		15.9		0.4		0.8
	Expected return on plan assets		-18.3		-17.8		-		-
	Recognized net actuarial loss		5.8		7.3		-		0.1
	Amortization of prior service cost		0.1		-		-0.9		-1.9
	Net settlement gain		-		-		-		-1.6
	Net periodic pension cost (benefit)	$	5.2	$	6.3	$	-0.5	$	-2.5

Other_Comprehensive_Income_Tab

Other Comprehensive Income (Tables)	6 Months Ended
Other Comprehensive Income (Tables)	Jun. 30, 2014
Equity [Abstract]	'
Changes in Other Comprehensive Income	'


		Three Months Ended June 30,
		2014						2013
				Tax						Tax
				Benefit		Net of				Benefit		Net of
	(in millions)	Pre-Tax		(Expense)		Tax		Pre-Tax		(Expense)		Tax
	Unrealized gains (losses) on available-for-sale securities and
	derivative instruments:
	Unrealized gains (losses) arising during period (net of
	pre-tax, ceded unrealized gains (losses) of $0.7 million
	and ($0.8) million for the three months ended
	June 30, 2014 and 2013)	$	83.2		-29.2		54.0	$	-190	$	66.7	$	-123.3
	Less:
	Amount of realized gains from sales and other		-22.4		2.6		-19.8		-15		0.2		-14.8
	Portion of other-than-temporary impairment losses
	recognized in earnings		0.1		-		0.1		1.1		-0.4		0.7
	Net unrealized gains (losses)		60.9		-26.6		34.3		-203.9		66.5		-137.4
	Pension and postretirement benefits:
	Amortization of net actuarial loss and prior service cost
	recognized as net periodic benefit cost		2.5		-0.9		1.6		6.3		-2.2		4.1
	Cumulative foreign currency translation adjustment:
	Foreign currency translation recognized during
	the period		4.8		-1.7		3.1		-0.1		-		-0.1
	Other comprehensive income (loss)	$	68.2	$	-29.2	$	39.0	$	-197.7	$	64.3	$	-133.4


		Six Months Ended June 30,
		2014						2013
				Tax						Tax
				Benefit		Net of				Benefit		Net of
	(in millions)	Pre-Tax		(Expense)		Tax		Pre-Tax		(Expense)		Tax
	Unrealized gains (losses) on available-for-sale securities and
	derivative instruments:
	Unrealized gains (losses) arising during period (net of
	pre-tax, ceded unrealized gains (losses) of $1.2 million
	and ($0.8) million for the six months ended June 30, 2014
	and 2013)	$	166.5	$	-55.3	$	111.2	$	-165	$	57.9	$	-107.1
	Less:
	Amount of realized gains from sales and other		-26.7		-1.5		-28.2		-23.8		-2.1		-25.9
	Portion of other-than-temporary impairment losses
	recognized in earnings		0.1		-		0.1		1.6		-0.6		1.0
	Net unrealized gains (losses)		139.9		-56.8		83.1		-187.2		55.2		-132
	Pension and postretirement benefits:
	Amortization of net actuarial loss and prior service cost
	recognized as net periodic benefit cost		5.2		-1.8		3.4		9.2		-3.2		6.0
	Cumulative foreign currency translation adjustment:
	Foreign currency translation recognized during
	the period		4.7		-1.7		3.0		-15.5		5.4		-10.1
	Other comprehensive income (loss)	$	149.8	$	-60.3	$	89.5	$	-193.5	$	57.4	$	-136.1


Reclassifications Out of Accumulated Other Comprehensive Income	'


		Three Months Ended				Six Months Ended
			June 30,			June 30,

	(in millions)		2014	2013		2014		2013

		Amount Reclassified from
	Details about Accumulated Other	Accumulated Other								Affected Line Item in the Statement
	Comprehensive Income Components	Comprehensive Income								Where Net Income is Presented
	Unrealized gains on available-for-sale
	securities and derivative instruments	$	22.4	$	15.1	$	26.7	$	23.8	Net realized gains from sales and other
										Net other-than-temporary impairment
										(losses) on investments recognized
			-0.1		-1.1		-0.1		-1.6	in earnings
	Other		-		-0.1		-		-
			22.3		13.9		26.6		22.2	Total before tax
			-2.6		0.2		1.5		2.7	Tax (expense) benefit
			19.7		14.1		28.1		24.9	Net of tax
	Amortization of defined benefit pension									Loss adjustment expenses and other
	and postretirement plans		-2.5		-6.3		-5.2		-9.2	operating expenses
			0.9		2.2		1.8		3.2	Tax benefit
			-1.6		-4.1		-3.4		-6	Net of tax
	Total reclassifications for the period	$	18.1	$	10.0	$	24.7	$	18.9	Net of tax

Segment_Information_Tables

Segment Information (Tables)	6 Months Ended
Segment Information (Tables)	Jun. 30, 2014
Segment Information [Abstract]	'
Financial Information with Respect to Business Segments	'


			Three Months Ended				Six Months Ended
			June 30,				June 30,
	(in millions)		2014		2013		2014		2013
	Operating revenues:
	Commercial Lines	$	556.9	$	523.7	$	1,108.9	$	1,038.4
	Personal Lines		371.4		388.9		742.4		780.0
	Chaucer		320.6		253.5		635.1		517.4
	Other		1.9		2.8		3.9		5.3
	Total		1,250.8		1,168.9		2,490.3		2,341.1
	Net realized investment gains		22.2		13.7		26.6		21.8
	Total revenues	$	1,273.0	$	1,182.6	$	2,516.9	$	2,362.9
	Operating income (loss) before income taxes:
	Commercial Lines:
	GAAP underwriting gain (loss)	$	7.3	$	-9.5	$	-14	$	-12.6
	Net investment income		37.2		36.0		74.5		72.1
	Other expense		-0.3		-0.3		-0.2		-0.3
	Commercial Lines operating income		44.2		26.2		60.3		59.2
	Personal Lines:
	GAAP underwriting income (loss)		3.6		-0.3		5.7		9.8
	Net investment income		18.0		19.1		35.9		38.1
	Other income		1.1		1.1		2.7		2.5
	Personal Lines operating income		22.7		19.9		44.3		50.4
	Chaucer:
	GAAP underwriting income		24.3		24.7		60.8		57.7
	Net investment income		10.7		10.7		21.2		21.2
	Other income (expense)		3.1		1.5		5.3		-1.1
	Chaucer operating income		38.1		36.9		87.3		77.8
	Other:
	GAAP underwriting loss		-0.9		-1		-1.4		-2.1
	Net investment income		1.1		2.1		2.4		3.8
	Other net expenses		-3		-3		-5.7		-5.8
	Other operating loss		-2.8		-1.9		-4.7		-4.1
	Operating income before interest expense and income taxes		102.2		81.1		187.2		183.3
	Interest on debt		-16.3		-17.4		-32.6		-32.1
	Operating income before income taxes		85.9		63.7		154.6		151.2
	Non-operating income items:
	Net realized investment gains		22.2		13.7		26.6		21.8
	Net loss from repayment of debt		-		-11.3		-		-19.1
	Net (costs) benefit related to acquired businesses		-0.2		-0.2		-1.1		0.2
	Net foreign exchange (losses) gains		-0.2		-		-0.3		0.7
	Income before income taxes	$	107.7	$	65.9	$	179.8	$	154.8


Identifiable Assets by Business Segment	'


		June 30,		December 31,
		2014		2013

	(in millions)	Identifiable Assets
	U.S. Companies	$	9,176.9	$	8,962.6
	Chaucer		4,672.9		4,301.2
	Discontinued operations		115.0		114.9
	Total	$	13,964.8	$	13,378.7

Stockbased_Compensation_Tables

Stock-based Compensation (Tables)	6 Months Ended
Stock-based Compensation (Tables)	Jun. 30, 2014
Stock-based Compensation [Abstract]	'
Compensation Cost and Related Tax Benefits	'


		Three Months Ended						Six Months Ended
		June 30,						June 30,
	(in millions)	2014			2013			2014			2013
	Stock-based compensation expense	$	3.8		$	2.1		$	7.3		$	5.7
	Tax benefit		-1.4			-0.7			-2.6			-2
	Stock-based compensation expense, net of taxes	$	2.4		$	1.4		$	4.7		$	3.7


Summary of Stock Option Plan Activity	'


		Six Months Ended June 30,
		2014					2013
	(in whole shares and dollars)	Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price
	Outstanding, beginning of period	2,049,173		$	41.18		2,892,882		$	38.28
	Granted	683,200			58.02		537,300			42.51
	Exercised	-243,491			38.66		-798,790			32.84
	Forfeited or cancelled	-34,085			41.84		-164,500			41.74
	Outstanding, end of period	2,454,797			46.10		2,466,892			40.74


Summary of Restricted Stock Activity	'


		Six Months Ended June 30,
		2014					2013
	(in whole shares and dollars)	Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value
	Time-based restricted stock units:
	Outstanding, beginning of period	525,980		$	41.20		750,837		$	40.15
	Granted	94,240			58.02		130,912			42.80
	Vested	-202,006			42.09		-259,440			39.60
	Forfeited	-9,300			40.73		-37,257			40.49
	Outstanding, end of period	408,914			44.65		585,052			40.96

	Performance-based and market-based restricted stock units:
	Outstanding, beginning of period	184,626		$	40.42		132,775		$	39.97
	Granted	60,338			55.73		79,850			41.67
	Vested	-22,826			44.78		-			-
	Forfeited	-3,800			37.90		-22,700			40.83
	Outstanding, end of period	218,338			44.24		189,925			40.58

Earnings_Per_Share_and_Shareho1

Earnings Per Share and Shareholders' Equity Transactions (Tables)	6 Months Ended
	Jun. 30, 2014
Earnings Per Share and Shareholdersb Equity Transactions [Abstract]	'
Information Regarding Basic and Diluted Earnings Per Share	'


		Three Months Ended				Six Months Ended
		June 30,				June 30,

	(in millions, except per share data)		2014		2013		2014		2013
	Basic shares used in the calculation of earnings per share		44.1		44.0		44.0		44.3
	Dilutive effect of securities:
	Employee stock options		0.4		0.4		0.4		0.3
	Non-vested stock grants		0.4		0.4		0.4		0.4
	Diluted shares used in the calculation of earnings per share		44.9		44.8		44.8		45.0
	Per share effect of dilutive securities on income from continuing operations	$	-0.03	$	-0.02	$	-0.06	$	-0.05
	Per share effect of dilutive securities on income from net income	$	-0.04	$	-0.02	$	-0.06	$	-0.04

Income_Taxes_Detail

Income Taxes - (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Income Taxes [Abstract]	'	'
Federal income tax expense	$24.70	$17.60
Foreign income tax expense	17.9	17.7
Foreign income permanently reinvested	5.6	10.3
Effective Income Tax Rate Reconciliation, Deduction, Amount	4.4	'
Estimated taxes payable on undistributed earnings	14.9	'
Liability for uncertain tax positions	$4.80	'

Investments_Narrative_Detail

Investments - (Narrative) (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Investments [Abstract]	'	'	'	'	'
Net unrealized gains on impaired securities	$14.40	'	$14.40	'	$16.40
Other Comprehensive Income Loss Reclassification Adjustment From A O C I For Writedown Of Securities Before Tax	0.1	1.1	0.1	1.6	'
Other-than-temporary impairments	'	1.3	'	2	'
Net other-than-temporary impairment losses on securities recognized in earnings	0.1	1.1	0.1	1.6	'
Amount transferred from unrealized losses in accumulated other comprehensive income	'	0.2	'	0.4	'
Restricted assets, fixed maturities	403	'	403	'	'
Restricted assets, cash and cash equivalents	$75	'	$75	'	'

Investments_Schedule_of_Availa

Investments (Schedule of Available-for-sale Securities Reconciliation) (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost or Cost	$6,785.10	$6,815.20
Gross Unrealized Gains	309.8	246.9
Gross Unrealized Loss	36.4	91.5
Fair Value	7,058.50	6,970.60
OTTI Unrealized Losses	7.8	10.2
US Treasury and Government [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost or Cost	403.5	417.5
Gross Unrealized Gains	6	3.3
Gross Unrealized Loss	6.3	14.2
Fair Value	403.2	406.6
Foreign Government Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost or Cost	319.7	304.5
Gross Unrealized Gains	2.6	2.1
Gross Unrealized Loss	1.3	1.6
Fair Value	321	305
Municipal [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost or Cost	1,080.40	1,108
Gross Unrealized Gains	59.5	37.4
Gross Unrealized Loss	6.4	19.1
Fair Value	1,133.50	1,126.30
Corporate Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost or Cost	3,718.30	3,690.20
Gross Unrealized Gains	205.4	171.5
Gross Unrealized Loss	15	37.5
Fair Value	3,908.70	3,824.20
OTTI Unrealized Losses	7.4	8.6
Residential Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost or Cost	697.3	722.8
Gross Unrealized Gains	22.1	20.1
Gross Unrealized Loss	5.8	14.1
Fair Value	713.6	728.8
OTTI Unrealized Losses	0.4	1.6
Commercial Mortgage Backed Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost or Cost	395.1	405.9
Gross Unrealized Gains	12.5	10.5
Gross Unrealized Loss	1.5	4.8
Fair Value	406.1	411.6
Asset-backed Securities, Securitized Loans and Receivables [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost or Cost	170.8	166.3
Gross Unrealized Gains	1.7	2
Gross Unrealized Loss	0.1	0.2
Fair Value	172.4	168.1
Equity Securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Amortized Cost or Cost	446.4	366.5
Gross Unrealized Gains	84.9	66.9
Gross Unrealized Loss	0.8	3.2
Fair Value	$530.50	$430.20

Investments_Investments_Classi

Investments (Investments Classified by Contractual Maturity Date) (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Investments [Abstract]	'	'
Due in one year or less, Amortized Cost	$400.60	'
Due after one year through five years, Amortized Cost	2,329.20	'
Due after five years through ten years, Amortized Cost	2,116.50	'
Due after ten years, Amortized Cost	675.6	'
Gross fixed maturities, Amortized Cost	5,521.90	'
Mortgage-backed and asset-backed securities, Amortized Cost	1,263.20	'
Total fixed maturities, Amortized Cost	6,785.10	6,815.20
Due in one year or less, Fair Value	404.8	'
Due after one year through five years, Fair Value	2,437.40	'
Due after five years through ten years, Fair Value	2,215.10	'
Due after ten years, Fair Value	709.1	'
Gross fixed maturities, Fair Value	5,766.40	'
Mortgage-backed and asset-backed securities, Fair Value	1,292.10	'
Fixed maturities, Fair Value	$7,058.50	$6,970.60

Investments_Schedule_of_Unreal

Investments (Schedule of Unrealized Loss on Investments) (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	$5.20	$70.50
12 months or less, Fair Value	471.1	2,221.50
Greater than 12 months, Gross Unrealized Losses	32	24.2
Greater than 12 months, Fair Value	870.2	227.3
Total, Gross Unrealized Losses	37.2	94.7
Total, Fair Value	1,341.30	2,448.80
Investment grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	4.4	64.7
12 months or less, Fair Value	440.5	2,102.40
Greater than 12 months, Gross Unrealized Losses	29.4	21.9
Greater than 12 months, Fair Value	841.8	203.7
Total, Gross Unrealized Losses	33.8	86.6
Total, Fair Value	1,282.30	2,306.10
Below Investment Grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	0.8	3
12 months or less, Fair Value	20.6	73.9
Greater than 12 months, Gross Unrealized Losses	1.8	1.9
Greater than 12 months, Fair Value	25	22.9
Total, Gross Unrealized Losses	2.6	4.9
Total, Fair Value	45.6	96.8
Debt Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	5.2	67.7
12 months or less, Fair Value	461.1	2,176.30
Greater than 12 months, Gross Unrealized Losses	31.2	23.8
Greater than 12 months, Fair Value	866.8	226.6
Total, Gross Unrealized Losses	36.4	91.5
Total, Fair Value	1,327.90	2,402.90
US Treasury and Government [Member] \| Investment grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	'	12.3
12 months or less, Fair Value	6.4	247.9
Greater than 12 months, Gross Unrealized Losses	6.3	1.9
Greater than 12 months, Fair Value	152	18.8
Total, Gross Unrealized Losses	6.3	14.2
Total, Fair Value	158.4	266.7
Foreign Government Debt Securities [Member] \| Investment grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	0.8	1.5
12 months or less, Fair Value	100.7	129
Greater than 12 months, Gross Unrealized Losses	0.5	0.1
Greater than 12 months, Fair Value	56.1	17.3
Total, Gross Unrealized Losses	1.3	1.6
Total, Fair Value	156.8	146.3
Municipal [Member] \| Investment grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	0.4	14.8
12 months or less, Fair Value	53.3	345.3
Greater than 12 months, Gross Unrealized Losses	5.7	4.3
Greater than 12 months, Fair Value	158.9	39.9
Total, Gross Unrealized Losses	6.1	19.1
Total, Fair Value	212.2	385.2
Municipal [Member] \| Below Investment Grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	0.3	'
12 months or less, Fair Value	4.4	'
Total, Gross Unrealized Losses	0.3	'
Total, Fair Value	4.4	'
Corporate Debt Securities [Member] \| Investment grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	2.6	21.4
12 months or less, Fair Value	198.4	872.7
Greater than 12 months, Gross Unrealized Losses	10.1	11.6
Greater than 12 months, Fair Value	259.7	87.7
Total, Gross Unrealized Losses	12.7	33
Total, Fair Value	458.1	960.4
Corporate Debt Securities [Member] \| Below Investment Grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	0.5	2.9
12 months or less, Fair Value	16.2	71.9
Greater than 12 months, Gross Unrealized Losses	1.8	1.6
Greater than 12 months, Fair Value	25	21.4
Total, Gross Unrealized Losses	2.3	4.5
Total, Fair Value	41.2	93.3
Residential Mortgage Backed Securities [Member] \| Investment grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	0.5	10.3
12 months or less, Fair Value	39.7	321.1
Greater than 12 months, Gross Unrealized Losses	5.3	3.4
Greater than 12 months, Fair Value	135.5	29.5
Total, Gross Unrealized Losses	5.8	13.7
Total, Fair Value	175.2	350.6
Residential Mortgage Backed Securities [Member] \| Below Investment Grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	'	0.1
12 months or less, Fair Value	'	2
Greater than 12 months, Gross Unrealized Losses	'	0.3
Greater than 12 months, Fair Value	'	1.5
Total, Gross Unrealized Losses	'	0.4
Total, Fair Value	'	3.5
Commercial Mortgage Backed Securities [Member] \| Investment grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	0.1	4.2
12 months or less, Fair Value	31.3	155.4
Greater than 12 months, Gross Unrealized Losses	1.4	0.6
Greater than 12 months, Fair Value	65.4	10.2
Total, Gross Unrealized Losses	1.5	4.8
Total, Fair Value	96.7	165.6
Asset-backed Securities, Securitized Loans and Receivables [Member] \| Investment grade	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	'	0.2
12 months or less, Fair Value	10.7	31
Greater than 12 months, Gross Unrealized Losses	0.1	'
Greater than 12 months, Fair Value	14.2	0.3
Total, Gross Unrealized Losses	0.1	0.2
Total, Fair Value	24.9	31.3
Equity Securities	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
12 months or less, Gross Unrealized Losses	'	2.8
12 months or less, Fair Value	10	45.2
Greater than 12 months, Gross Unrealized Losses	0.8	0.4
Greater than 12 months, Fair Value	3.4	0.7
Total, Gross Unrealized Losses	0.8	3.2
Total, Fair Value	$13.40	$45.90

Investments_Schedule_of_Realiz

Investments (Schedule of Realized Gain (Loss)) (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Debt Securities [Member]	'	'	'	'
Gain (Loss) on Investments [Line Items]	'	'	'	'
Proceeds from Sales	$70.50	$148.50	$208.10	$285.70
Gross Gains	1.1	3	3.3	4.6
Gross Losses	1.1	0.4	2.3	1
Equity Securities	'	'	'	'
Gain (Loss) on Investments [Line Items]	'	'	'	'
Proceeds from Sales	60	44.4	72.4	78.9
Gross Gains	22.2	10.4	24.1	17
Gross Losses	$0.70	$0.30	$0.80	$0.30

Investments_Rollforward_of_Cum

Investments (Rollforward of Cumulative Amounts Related to Credit Loss Portion of OTTI Losses) (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Investments [Abstract]	'	'	'	'
Credit losses at beginning of period	$5.30	$8.60	$7.80	$8.60
Credit losses for which an OTTI was not previously recognized	'	0.1	'	0.3
Additional credit losses on securities for which an OTTI was previously recognized	'	'	'	0.2
Reductions for securities sold, matured or called	-0.6	-1.4	-3.1	-1.8
Reductions for securities reclassified as intended to sell	-0.4	'	-0.4	'
Credit losses at end of period	$4.30	$7.30	$4.30	$7.30

Fair_Value_Narrative_Detail

Fair Value (Narrative) (Detail) (USD $)	6 Months Ended
Fair Value (Narrative) (Detail) (USD $)	Jun. 30, 2014	Jun. 30, 2013
Fair Value Disclosures [Abstract]	'	'
Transfer between Level 1 and Level 2	$0	$0

Fair_Value_Fair_Value_of_Finan

Fair Value (Fair Value of Financial Instruments) (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Cash and cash equivalents	$606.20	$486.20	$690.40	$564.80
Fixed maturities	7,058.50	6,970.60	'	'
Equity securities	530.5	430.2	'	'
Other investments	238.5	192.5	'	'
Debt	903.9	903.9	'	'
Carrying Value [Member]	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Cash and cash equivalents	606.2	486.2	'	'
Fixed maturities	7,058.50	6,970.60	'	'
Equity securities	530.5	430.2	'	'
Other investments	218.4	173.1	'	'
Total financial assets	8,413.60	8,060.10	'	'
Debt	903.9	903.9	'	'
Fair Value [Member]	'	'	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'	'	'
Cash and cash equivalents	606.2	486.2	'	'
Fixed maturities	7,058.50	6,970.60	'	'
Equity securities	530.5	430.2	'	'
Other investments	220.9	173.7	'	'
Total financial assets	8,416.10	8,060.70	'	'
Debt	$1,030.70	$961.70	'	'

Fair_Value_Assets_and_Liabilit

Fair Value (Assets and Liabilities Measured at Fair Value on Recurring Basis) (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	$7,058.50	$6,970.60
Equity securities	530.5	430.2
Other investments	238.5	192.5
Fair Value, Measurements, Recurring	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Other investments	138.5	153.2
Total investment assets at fair value	7,718.20	7,544.70
Fair Value, Measurements, Recurring \| Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Total investment assets at fair value	723.3	595.1
Fair Value, Measurements, Recurring \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Other investments	134.9	149.6
Total investment assets at fair value	6,927.60	6,845.40
Fair Value, Measurements, Recurring \| Level 3	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Other investments	3.6	3.6
Total investment assets at fair value	67.3	104.2
Fair Value, Measurements, Recurring \| Fixed Maturities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	7,058.50	6,970.60
Fair Value, Measurements, Recurring \| Fixed Maturities \| Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	203.3	212.8
Fair Value, Measurements, Recurring \| Fixed Maturities \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	6,792.70	6,695.80
Fair Value, Measurements, Recurring \| Fixed Maturities \| Level 3	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	62.5	62
Fair Value, Measurements, Recurring \| Fixed Maturities \| U.S. Treasury And Government Agencies	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	403.2	406.6
Fair Value, Measurements, Recurring \| Fixed Maturities \| U.S. Treasury And Government Agencies \| Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	160.5	167.2
Fair Value, Measurements, Recurring \| Fixed Maturities \| U.S. Treasury And Government Agencies \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	242.7	239.4
Fair Value, Measurements, Recurring \| Fixed Maturities \| Foreign Government Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	321	305
Fair Value, Measurements, Recurring \| Fixed Maturities \| Foreign Government Debt Securities [Member] \| Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	42.8	45.6
Fair Value, Measurements, Recurring \| Fixed Maturities \| Foreign Government Debt Securities [Member] \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	278.2	259.4
Fair Value, Measurements, Recurring \| Fixed Maturities \| Municipal [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,133.50	1,126.30
Fair Value, Measurements, Recurring \| Fixed Maturities \| Municipal [Member] \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	1,106.70	1,100.70
Fair Value, Measurements, Recurring \| Fixed Maturities \| Municipal [Member] \| Level 3	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	26.8	25.6
Fair Value, Measurements, Recurring \| Fixed Maturities \| Corporate Debt Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	3,908.70	3,824.20
Fair Value, Measurements, Recurring \| Fixed Maturities \| Corporate Debt Securities [Member] \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	3,895.50	3,811.20
Fair Value, Measurements, Recurring \| Fixed Maturities \| Corporate Debt Securities [Member] \| Level 3	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	13.2	13
Fair Value, Measurements, Recurring \| Fixed Maturities \| Residential Mortgage Backed Securities U S Agency Backed	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	586.2	573.2
Fair Value, Measurements, Recurring \| Fixed Maturities \| Residential Mortgage Backed Securities U S Agency Backed \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	586.2	573.2
Fair Value, Measurements, Recurring \| Fixed Maturities \| Residential Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	127.4	155.6
Fair Value, Measurements, Recurring \| Fixed Maturities \| Residential Mortgage Backed Securities [Member] \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	127.4	155.1
Fair Value, Measurements, Recurring \| Fixed Maturities \| Residential Mortgage Backed Securities [Member] \| Level 3	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	'	0.5
Fair Value, Measurements, Recurring \| Fixed Maturities \| Commercial Mortgage Backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	406.1	411.6
Fair Value, Measurements, Recurring \| Fixed Maturities \| Commercial Mortgage Backed Securities [Member] \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	383.6	388.7
Fair Value, Measurements, Recurring \| Fixed Maturities \| Commercial Mortgage Backed Securities [Member] \| Level 3	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	22.5	22.9
Fair Value, Measurements, Recurring \| Fixed Maturities \| Asset-backed Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	172.4	168.1
Fair Value, Measurements, Recurring \| Fixed Maturities \| Asset-backed Securities [Member] \| Level 2	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fixed maturities	172.4	168.1
Fair Value, Measurements, Recurring \| Equity Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	521.2	420.9
Fair Value, Measurements, Recurring \| Equity Securities \| Level 1	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	520	382.3
Fair Value, Measurements, Recurring \| Equity Securities \| Level 3	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Equity securities	$1.20	$38.60

Fair_Value_Estimated_Fair_Valu

Fair Value (Estimated Fair Values of Financial Instruments Not Carried at Fair Value) (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Equity securities	$530.50	$430.20
Estimate of Fair Value, Fair Value Disclosure	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Cash and cash equivalents	606.2	486.2
Equity securities	9.3	9.3
Other investments	82.4	20.5
Debt	1,030.70	961.7
Estimate of Fair Value, Fair Value Disclosure \| Level 1	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Cash and cash equivalents	606.2	486.2
Estimate of Fair Value, Fair Value Disclosure \| Level 2	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Equity securities	9.3	9.3
Other investments	58.6	2.7
Debt	1,030.70	961.7
Estimate of Fair Value, Fair Value Disclosure \| Level 3	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Other investments	$23.80	$17.80

Fair_Value_Fair_Value_on_Recur

Fair Value (Fair Value on Recurring Basis Using Significant Unobservable Inputs (Level 3)) (Detail) (USD $)

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

In Millions, unless otherwise specified

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Mar. 31, 2014

Jun. 30, 2014

Jun. 30, 2013

Mar. 31, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Jun. 30, 2014

Jun. 30, 2013

Mar. 31, 2014

Fixed Maturities

Equity Securities and Other Investments

Municipal [Member]

Corporate Debt Securities [Member]

Residential Mortgage Backed Securities [Member]

Commercial Mortgage Backed Securities [Member]

Asset-backed Securities [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Beginning Balance

$70.10

$105.60

$104.20

$102.70

$65.30

$77

$62

$74.70

$29.60

$28.80

$25.60

$19.40

$22.80

$13

$26.40

$13.20

$0.50

$0.70

$0.60

$22.50

$24.80

$22.90

$26.70

$1.50

$28.60

$42.20

$28

$4.80

Transfers into Level 3

2.2

9.9

2.2

9.9

2.2

9.7

0.2

Transfers out of Level 3

-2.6

-2.2

-40

-4.6

-2.6

-2.2

-2.6

-3.7

-2.6

-2.2

-1.5

-37.4

-0.9

Included in earnings

-0.4

Included in other comprehensive income - net appreciation (depreciation) on available-for-sale securities

0.7

1.5

2.5

0.7

-2.2

1.5

-2.7

0.3

-0.4

0.6

-0.3

-0.9

0.2

-1

0.4

-0.9

0.7

-1.4

3.7

5.2

Purchases

2.5

Sales

-0.9

-1

-3.1

-7

-0.9

-1

-3.1

-7

-0.5

-1.5

-0.9

-0.2

-4.3

-0.5

-0.1

-0.4

-0.3

-1.1

-1.7

Ending Balance

$67.30

$103.90

$67.30

$103.90

$62.50

$71.60

$62.50

$71.60

$26.80

$27.90

$26.80

$27.90

$19.50

$13.20

$19.50

$13.20

$0.60

$22.50

$23.60

$22.50

$23.60

$32.30

$4.80

$32.30

$4.80

Fair_Value_Summary_Gains_and_L

Fair Value (Summary Gains and Losses due to Changes in Fair Value Recorded in Income) (Detail) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings 1	$0.40

Fair_Value_Schedule_of_Additio

Fair Value (Schedule of Additional Information About Significant Unobservable Inputs Used in Fair Valuations of Level 3) (Detail) (USD $)

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Dec. 31, 2013

In Millions, unless otherwise specified

Corporate Debt Securities [Member]

Fixed Maturities

Other securities

Equity Securities

Discount For Small Issue Size

Municipal [Member]

Corporate Debt Securities [Member]

Residential Mortgage Backed Securities [Member]

Commercial Mortgage Backed Securities [Member]

Discounted cash flow [Member]

Market comparables [Member]

Discounted cash flow [Member]

Discount For Small Issue Size

Discount For Above Market Coupon

Discounted cash flow [Member]

Discount For Small Issue Size

Discount For Above Market Coupon

Discounted cash flow [Member]

Discount For Small Issue Size

Discounted cash flow [Member]

Discount For Small Issue Size

Discount For Above Market Coupon

Discount For Credit Stress

Discount For Lease Structure

Level 3

Discounted cash flow [Member]

Level 3

Discounted cash flow [Member]

Level 3

Discounted cash flow [Member]

Level 3

Discounted cash flow [Member]

Maximum

Level 3

Minimum

Maximum

Minimum

Maximum

Minimum

Maximum

Minimum

Maximum

Minimum

Maximum

Fair Value [Line Items]

Fair value measurement weighted average market multiples

1.3

Fair Value

$67.30

$70.10

$104.20

$103.90

$105.60

$102.70

$26.80

$25.60

$12.90

$12.80

$0.50

$22.50

$22.90

$3.60

$1.10

$38.50

Weighted average rate

1.00%

2.10%

2.30%

0.60%

1.00%

4.00%

0.40%

0.50%

0.30%

1.00%

0.50%

0.30%

1.00%

0.60%

0.30%

0.80%

0.50%

0.60%

0.50%

0.80%

0.50%

0.30%

18.00%

Pension_and_Other_Postretireme2

Pension and Other Postretirement Benefit Plans (Components of Net Periodic Benefit Cost) (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Pension Plans	'	'	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'	'
Service cost - benefits earned during the period	$0.30	$0.50	$0.70	$0.90
Interest cost	8.5	8	16.9	15.9
Expected return on plan assets	-9.1	-8.9	-18.3	-17.8
Recognized net actuarial loss	2.9	3.6	5.8	7.3
Amortization of prior service cost	0.1	'	0.1	'
Net periodic pension cost (benefit)	2.7	3.2	5.2	6.3
Postretirement Plans	'	'	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'	'
Service cost - benefits earned during the period	'	0.1	'	0.1
Interest cost	0.2	0.3	0.4	0.8
Recognized net actuarial loss	'	'	'	0.1
Amortization of prior service cost	-0.5	-1	-0.9	-1.9
Net settlement gain	'	-1.6	'	-1.6
Net periodic pension cost (benefit)	($0.30)	($2.20)	($0.50)	($2.50)

Other_Comprehensive_Income_Nar

Other Comprehensive Income (Narrative) (Detail) (Defined Benefit Pension and Postretirement Plans:)	6 Months Ended
	Jun. 30, 2014
Defined Benefit Pension and Postretirement Plans:	'
Comprehensive Income (Loss) [Line Items]	'
Loss Adjustment Expense	40.00%
Percentage Of Other Operating Expenses	60.00%

Other_Comprehensive_Income_Cha

Other Comprehensive Income (Changes in Other Comprehensive Income) (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Equity [Abstract]	'	'	'	'
Unrealized gains (losses) arising during period, Pre-Tax	$83.20	($190)	$166.50	($165)
Amount of realized gains from sales and other, Pre-tax	-22.4	-15	-26.7	-23.8
Portion of other-than-temporary impairment losses recognized in earnings, Pre-tax	0.1	1.1	0.1	1.6
Net unrealized gains (losses), Pre-tax	60.9	-203.9	139.9	-187.2
Amortization of net actuarial loss and prior service cost recognized as net periodic benefit cost, Pre-tax	2.5	6.3	5.2	9.2
Foreign currency translation recognized during the period, Pre-tax	4.8	-0.1	4.7	-15.5
Other comprehensive income (loss), Pre-tax	68.2	-197.7	149.8	-193.5
Unrealized gains (losses) arising during period, Tax Benefit (Expense)	-29.2	66.7	-55.3	57.9
Amount of realized gains from sales and other, Tax Benefit (Expense)	2.6	0.2	-1.5	-2.1
Portion of other-than-temporary impairment losses recognized in earnings, Tax Benefit (Expense)	'	-0.4	'	-0.6
Net unrealized gains (losses), Tax Benefit (Expense)	-26.6	66.5	-56.8	55.2
Amortization of net actuarial loss and prior service cost recognized as net periodic benefit cost, Tax Benefit (Expense)	-0.9	-2.2	-1.8	-3.2
Foreign currency translation recognized during the period, Tax Benefit (Expense)	-1.7	'	-1.7	5.4
Other comprehensive income (loss), Tax Benefit (Expense)	-29.2	64.3	-60.3	57.4
Unrealized gains (losses) arising during period, Net of Tax	54	-123.3	111.2	-107.1
Amount of realized gains from sales and other, Net of Tax	-19.8	-14.8	-28.2	-25.9
Portion of other-than-temporary impairment losses recognized in earnings, Net of Tax	0.1	0.7	0.1	1
Total available-for-sale securities and derivative instruments	34.3	-137.4	83.1	-132
Amortization of net actuarial loss and prior service cost recognized as net periodic benefit cost, Net of Tax	1.6	4.1	3.4	6
Foreign currency translation recognized during the period, Net of Tax	3.1	-0.1	3	-10.1
Other comprehensive income (loss), Net of Tax	39	-133.4	89.5	-136.1
Net of pre-tax, ceded unrealized gains (losses)	$0.70	($0.80)	$1.20	($0.80)

Other_Comprehensive_Income_Rec

Other Comprehensive Income (Reclassifications out of Accumulated Other Comprehensive Income) (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Net realized gains from sales and other	$22.30	$14.80	$26.70	$23.40
Total losses and expenses	-1,165.30	-1,116.70	-2,337.10	-2,208.10
Net other-than-temporary impairment losses on investments recognized in earnings	-0.1	-1.1	-0.1	-1.6
Total before tax	107.7	65.9	179.8	154.8
Tax benefit (expense)	-25.2	-12.8	-42.6	-35.3
Income from continuing operations	82.5	53.1	137.2	119.5
Income Loss From Discontinued Operations Net Of Tax	0.1	0.3	'	0.1
Net of tax	82.6	53.4	137.2	119.6
Reclassification out of Accumulated Other Comprehensive Income	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Other	'	-0.1	'	'
Net of tax	18.1	10	24.7	18.9
Reclassification out of Accumulated Other Comprehensive Income \| Net Unrealized Appreciation on Investments and Derivative Instruments:	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Net realized gains from sales and other	22.4	15.1	26.7	23.8
Net other-than-temporary impairment losses on investments recognized in earnings	-0.1	-1.1	-0.1	-1.6
Total before tax	22.3	13.9	26.6	22.2
Tax benefit (expense)	-2.6	0.2	1.5	2.7
Net of tax	19.7	14.1	28.1	24.9
Reclassification out of Accumulated Other Comprehensive Income \| Defined Benefit Pension and Postretirement Plans:	'	'	'	'
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]	'	'	'	'
Total losses and expenses	-2.5	-6.3	-5.2	-9.2
Tax benefit (expense)	0.9	2.2	1.8	3.2
Net of tax	($1.60)	($4.10)	($3.40)	($6)

Segment_Information_Narrative_

Segment Information - (Narrative) (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
	Jun. 30, 2014	Jun. 30, 2013	segment	Jun. 30, 2013
Segment Information [Abstract]	'	'	'	'
Operating segments	'	'	4	'
Net foreign currency transaction gains	$5.10	'	$5.80	'
Net foreign currency transaction losses	'	$5.60	'	$7.70

Segment_Information_Financial_

Segment Information (Financial Information with Respect to Business Segments) (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]	'	'	'	'
Operating revenues	$1,250.80	$1,168.90	$2,490.30	$2,341.10
Net realized investment gains	22.2	13.7	26.6	21.8
Net investment income	67	67.9	134	135.2
Total revenues	1,273	1,182.60	2,516.90	2,362.90
Operating income (loss) before interest expense and income taxes	102.2	81.1	187.2	183.3
Interest on debt	-16.3	-17.4	-32.6	-32.1
Operating income before income taxes	85.9	63.7	154.6	151.2
Net loss from repayment of debt	'	-11.3	'	-19.1
Net benefit (costs) related to acquired businesses	-0.2	-0.2	-1.1	0.2
Net foreign exchange gains (losses)	-0.2	'	-0.3	0.7
Income before income taxes	107.7	65.9	179.8	154.8
Commercial Lines	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Operating revenues	556.9	523.7	1,108.90	1,038.40
GAAP underwriting income (loss)	7.3	-9.5	-14	-12.6
Net investment income	37.2	36	74.5	72.1
Other income (expense)	-0.3	-0.3	-0.2	-0.3
Operating income (loss) before interest expense and income taxes	44.2	26.2	60.3	59.2
Personal Lines	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Operating revenues	371.4	388.9	742.4	780
GAAP underwriting income (loss)	3.6	-0.3	5.7	9.8
Net realized investment gains	18	19.1	35.9	38.1
Other income (expense)	1.1	1.1	2.7	2.5
Operating income (loss) before interest expense and income taxes	22.7	19.9	44.3	50.4
Chaucer	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Operating revenues	320.6	253.5	635.1	517.4
GAAP underwriting income (loss)	24.3	24.7	60.8	57.7
Net investment income	10.7	10.7	21.2	21.2
Other income (expense)	3.1	1.5	5.3	-1.1
Operating income (loss) before interest expense and income taxes	38.1	36.9	87.3	77.8
Other	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Operating revenues	1.9	2.8	3.9	5.3
GAAP underwriting income (loss)	-0.9	-1	-1.4	-2.1
Net investment income	1.1	2.1	2.4	3.8
Other net expenses	-3	-3	-5.7	-5.8
Operating income (loss) before interest expense and income taxes	-2.8	-1.9	-4.7	-4.1
Interest on debt	($16.30)	($17.40)	($32.60)	($32.10)

Segment_Information_Identifiab

Segment Information (Identifiable Assets by Business Segment) (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]	'	'
Discontinued operations	$115	$114.90
Identifiable assets	13,964.80	13,378.70
U.S. Companies	'	'
Segment Reporting Information [Line Items]	'	'
Identifiable assets	9,176.90	8,962.60
Chaucer	'	'
Segment Reporting Information [Line Items]	'	'
Identifiable assets	$4,672.90	$4,301.20

Stock_Based_Compensation_Narra

Stock Based Compensation (Narrative) (Detail)	6 Months Ended
Stock Based Compensation (Narrative) (Detail)	Jun. 30, 2014	Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Performance metric for performance based restricted stock units	100.00%	'
Performance metric for performance based restricted stock units minimum potential range	0.00%	'
Performance metric for performance based restricted stock units maximum potential range	200.00%	'
2014 Stock Plan [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Number of shares authorized under plan	6,100,000	'
Number of shares available for grant	6,096,349	'
ESPP Plan [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Number of shares authorized under plan	2,500,000	'
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	23,105	'
SIP Plan [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Number of shares authorized under plan	750,000	'
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number	2,737	'
Minimum \| 2014 Stock Plan [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Reduction in Shares Available for Grant per Share Issued	1	'
Maximum \| 2014 Stock Plan [Member]	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Reduction in Shares Available for Grant per Share Issued	3.8	'
Performance-based restricted stock units	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Granted, Shares	1,013	'
Performance And Market-Based Restricted Stock Units	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Granted, Shares	56,625	'
Performance And Market-Based Restricted Stock Units \| Senior management	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Performance metric, minimum	0.00%	'
Performance metric, maximum	150.00%	'
Market-based awards	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Granted, Shares	1,875	76,175

Stockbased_Compensation_Compen

Stock-based Compensation (Compensation Cost and Related Tax Benefits) (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Stock-based Compensation [Abstract]	'	'	'	'
Stock-based compensation expense	$3.80	$2.10	$7.30	$5.70
Tax benefit	-1.4	-0.7	-2.6	-2
Stock-based compensation expense, net of taxes	$2.40	$1.40	$4.70	$3.70

Stockbased_Compensation_Summar

Stock-based Compensation (Summary of Stock Option Plan Activity) (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Stock-based Compensation [Abstract]	'	'
Outstanding, beginning of period, Shares	2,049,173	2,892,882
Granted, Shares	683,200	537,300
Exercised, Shares	-243,491	-798,790
Forfeited or cancelled, Shares	-34,085	-164,500
Outstanding, end of period, Shares	2,454,797	2,466,892
Outstanding, beginning of period, Weighted Average Exercise Price	$41.18	$38.28
Granted, Weighted Average Exercise Price	$58.02	$42.51
Exercised, Weighted Average Exercise Price	$38.66	$32.84
Forfeited or cancelled, Weighted Average Exercise Price	$41.84	$41.74
Outstanding, end of period, Weighted Average Exercise Price	$46.10	$40.74

Stockbased_Compensation_Summar1

Stock-based Compensation (Summary of Restricted Stock Activity) (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Restricted Stock Units (RSUs) [Member]	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Outstanding, beginning of period, Shares	525,980	750,837
Granted, Shares	94,240	130,912
Vested, Shares	-202,006	-259,440
Forfeited, Shares	-9,300	-37,257
Outstanding, end of period, Shares	408,914	585,052
Outstanding, beginning of period, Weighted Average Grant Date Fair Value	$41.20	$40.15
Granted, Weighted Average Grant Date Fair Value	$58.02	$42.80
Vested, Weighted Average Grant Date Fair Value	$42.09	$39.60
Forfeited, Weighted Average Grant Date Fair Value	$40.73	$40.49
Outstanding, end of period, Weighted Average Grant Date Fair Value	$44.65	$40.96
Performance Shares [Member]	'	'
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]	'	'
Outstanding, beginning of period, Shares	184,626	132,775
Granted, Shares	60,338	79,850
Vested, Shares	-22,826	'
Forfeited, Shares	-3,800	-22,700
Outstanding, end of period, Shares	218,338	189,925
Outstanding, beginning of period, Weighted Average Grant Date Fair Value	$40.42	$39.97
Granted, Weighted Average Grant Date Fair Value	$55.73	$41.67
Vested, Weighted Average Grant Date Fair Value	$44.78	'
Forfeited, Weighted Average Grant Date Fair Value	$37.90	$40.83
Outstanding, end of period, Weighted Average Grant Date Fair Value	$44.24	$40.58

Earnings_Per_Share_and_Shareho2

Earnings Per Share and Shareholders Equity Transactions (Narrative) (Detail) (USD $)	3 Months Ended	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share and Shareholdersb Equity Transactions [Abstract]	'	'	'
Antidilutive securities excluded from calculation of earnings per share	0.7	0.7	0.7
Repurchases common stock, authorized	$600	$600	'
Repurchases common stock, available for repurchases	130.3	130.3	'
Repurchases common stock, shares	'	0.1	'
Repurchases common stock, value	'	$6.70	'

Earnings_Per_Share_and_Shareho3

Earnings Per Share and Shareholdersb Equity Transactions (Information Regarding Basic and Diluted Earnings Per Share) (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]	'	'	'	'
Basic shares used in the calculation of earnings per share	44.1	44	44	44.3
Diluted shares used in the calculation of earnings per share	44.9	44.8	44.8	45
Per share effect of dilutive securities on income from continuing operations	($0.03)	($0.02)	($0.06)	($0.05)
Per share effect of dilutive securities on income from net income	($0.04)	($0.02)	($0.06)	($0.04)
Employee Stock Option	'	'	'	'
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]	'	'	'	'
Dilutive effect of securities	0.4	0.4	0.4	0.3
Non-Vested Stock Grants	'	'	'	'
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]	'	'	'	'
Dilutive effect of securities	0.4	0.4	0.4	0.4

Commitments_and_Contingencies_

Commitments and Contingencies (Narrative) (Detail)	6 Months Ended
	Jun. 30, 2014
	plaintiff
Commitments and Contingencies [Abstract]	'
Participant's retirement age	'65 years
Treasury rate, years	'30 years
Named plaintiffs	2