Employers (EIG) 10-Q 30 Apr 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 24, 2015
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Entity Registrant Name	Employers Holdings, Inc.
Entity Central Index Key	1379041
Current Fiscal Year End Date	-19
Entity Well Know Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock Shares Outstanding		31,892,010
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1

Financial_statement_notes_DEI_

Financial statement notes DEI Document (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Amortization of deferred gain	$2,900	$3,300
Change to Contingent Profit Commission [Member]
Amortization of deferred gain	$200	$300

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Available for sale:
Fixed maturity securities at fair value (amortized cost $2,256,400 at March 31, 2015 and $2,186,100 at December 31, 2014)	$2,360,100	$2,275,700
Equity securities at fair value (cost $98,900 at March 31, 2015 and $97,800 at December 31, 2014)	172,600	172,700
Short-term investments at fair value (amortized cost $9,000 at March 31, 2015)	9,000	0
Total investments	2,541,700	2,448,400
Cash and cash equivalents	45,600	103,600
Restricted cash and cash equivalents	8,400	10,800
Accrued investment income	19,200	20,500
Premiums receivable (less bad debt allowance of $9,100 at March 31, 2015 and $7,900 at December 31, 2014)	296,300	295,800
Reinsurance recoverable for:
Paid losses	7,900	10,700
Unpaid losses, including bad debt allowance	663,000	669,500
Deferred policy acquisition costs	46,700	44,600
Deferred income taxes, net	43,400	49,700
Property and equipment, net	20,300	21,000
Intangible assets, net	8,900	9,000
Goodwill	36,200	36,200
Contingent commission receivable—LPT Agreement	26,600	26,400
Other assets	36,500	23,500
Total assets	3,800,700	3,769,700
Claims and policy liabilities:
Unpaid losses and loss adjustment expenses	2,370,300	2,369,700
Unearned premiums	324,600	310,800
Total claims and policy liabilities	2,694,900	2,680,500
Commissions and premium taxes payable	45,500	46,300
Accounts payable and accrued expenses	16,900	20,400
Deferred reinsurance gain—LPT Agreement	204,100	207,000
Notes payable	92,000	92,000
Other liabilities	37,800	36,700
Total liabilities	3,091,200	3,082,900
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.01 par value; 150,000,000 shares authorized; 55,248,130 and 54,866,802 shares issued and 31,875,156 and 31,493,828 shares outstanding at March 31, 2015 and December 31, 2014, respectively	600	600
Preferred stock, $0.01 par value; 25,000,000 shares authorized; none issued	0	0
Additional paid-in capital	348,700	346,600
Retained earnings	607,500	595,300
Accumulated other comprehensive income, net	115,300	106,900
Treasury stock, at cost (23,372,974 shares at March 31, 2015 and December 31, 2014)	-362,600	-362,600
Total stockholders’ equity	709,500	686,800
Total liabilities and stockholders’ equity	$3,800,700	$3,769,700

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parentheticals) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Available for sale:
Fixed maturity securities, amortized cost	$2,364,300	$2,283,900
Available for sale, short-term investments, at amortized cost	9,000	0
Premiums receivable, bad debt allowance	9,000	7,900
Reinsurance Recoverables on Unpaid Losses, Allowance	0	0
Stockholders' equity
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	55,248,130	54,866,802
Common stock, shares outstanding (in shares)	31,875,156	31,493,828
Preferred stock, par value (in dollars per share)	$0.01	$0.01
Preferred stock, shares authorized (in shares)	25,000,000	25,000,000
Preferred stock, shares issued (in shares)	0	0
Treasury stock, at cost (in shares)	23,372,974	23,372,974
Debt Securities [Member]
Available for sale:
Fixed maturity securities, amortized cost	2,256,400	2,186,100
Equity Securities [Member]
Available for sale:
Fixed maturity securities, amortized cost	98,900	97,800
Short-term Investments [Member]
Available for sale:
Fixed maturity securities, amortized cost	$9,000

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenues
Net premiums earned	$159,000	$167,200
Net investment income	16,900	18,000
Net realized gains on investments	1,200	3,300
Other income	100	0
Total revenues	177,200	188,500
Expenses
Losses and loss adjustment expenses	106,200	122,300
Commission expense	18,700	20,000
Underwriting and other operating expenses	33,500	33,300
Interest expense	700	800
Total expenses	159,100	176,400
Net income before income taxes	18,100	12,100
Income tax expense	4,100	1,300
Net income	14,000	10,800
Earnings per common share (Note 9):
Basic	$0.44	$0.34
Diluted	$0.43	$0.34
Cash dividends declared per common share	$0.06	$0.06
Comprehensive income
Unrealized gains during the period (net of tax expense of $5,000 and $5,500 for the three months ended March 31, 2015 and 2014, respectively)	9,200	10,200
Reclassification adjustment for realized gains in net income (net of taxes of $400 and $1,100 for the three months ended March 31, 2015 and 2014, respectively)	-800	-2,100
Other comprehensive income, net of tax	8,400	8,100
Total comprehensive income	22,400	18,900
Net realized gains on investments
Net realized gains on investments before credit related impairments on fixed maturity securities	1,200	3,300
Other than temporary impairment, credit losses recognized in earnings	0	0
Net realized gains on investments	$1,200	$3,300

Conolidated_Statements_of_Comp

Conolidated Statements of Comprehensive Income (Parentheticals) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Statement Parenthetical [Abstract]
Other comprehensive income (loss), unrealized holding gain (loss) on securities arising during period, tax	$5,000	$5,500
Other comprehensive income (loss), reclassification adjustment for sale of securities included in net income, tax	$400	$1,200

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating activities
Net income	$14,000	$10,800
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,700	1,800
Stock-based compensation	1,800	1,600
Amortization of premium on investments, net	3,200	2,500
Deferred income tax expense	1,800	-1,000
Realized gains on investments, net	-1,200	-3,300
Excess tax benefits from stock-based compensation	-600	-1,100
Other	1,600	200
Change in operating assets and liabilities:
Premiums receivable	-1,600	-15,000
Reinsurance recoverable for paid and unpaid losses	9,300	7,400
Federal income taxes	-1,600	1,400
Unpaid losses and loss adjustment expenses	600	27,700
Unearned premiums	13,800	16,700
Accounts payable, accrued expenses and other liabilities	-1,500	-3,400
Deferred reinsurance gain—LPT Agreement	-2,900	-3,900
Contingent commission receivable—LPT Agreement	-200	-400
Other	-13,400	-3,400
Net cash provided by operating activities	24,800	38,600
Investing activities
Purchase of fixed maturity securities	-168,000	-94,500
Purchase of equity securities	-8,000	-7,800
Proceeds from sale of fixed maturity securities	0	35,100
Proceeds from sale of equity securities	8,200	7,900
Proceeds from maturities and redemptions of investments	85,100	42,400
Proceeds from sale of fixed assets	0	0
Capital expenditures	-900	-1,500
Change in restricted cash and cash equivalents	2,400	-2,400
Net cash used in investing activities	-81,200	-20,800
Financing activities
Cash transactions related to stock-based compensation	-300	-400
Dividends paid to stockholders	-1,900	-1,900
Excess tax benefits from stock-based compensation, financing activities	600	1,100
Net cash used in financing activities	-1,600	-1,200
Net (decrease) increase in cash and cash equivalents	-58,000	16,600
Cash and cash equivalents at the beginning of the period	103,600	34,500
Cash and cash equivalents at the end of the period	$45,600	$51,100

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Basis of Presentation [Abstract]
Basis of Presentation	Basis of Presentation and Summary of Operations
	Employers Holdings, Inc. (EHI) is a Nevada holding company. Through its wholly owned insurance subsidiaries, Employers Insurance Company of Nevada (EICN), Employers Compensation Insurance Company (ECIC), Employers Preferred Insurance Company (EPIC), and Employers Assurance Company (EAC), EHI is engaged in the commercial property and casualty insurance industry, specializing in workers' compensation products and services. Unless otherwise indicated, all references to the “Company” refer to EHI, together with its subsidiaries.
	The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities Exchange Act of 1934, as amended. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal, recurring adjustments) necessary for a fair presentation of the Company’s consolidated financial position and results of operations for the periods presented have been included. The results of operations for an interim period are not necessarily indicative of the results for an entire year. These financial statements have been prepared consistent with the accounting policies described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014.
	The Company considers an operating segment to be any component of its business whose operating results are regularly reviewed by the Company’s chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance based on discrete financial information. Currently, the Company has one operating segment, workers’ compensation insurance and related services.
	Use of Estimates
	The preparation of the consolidated financial statements in conformity with GAAP requires management 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 consolidated financial statements, as well as the reported amounts of revenues and expenses during the reporting period. As a result, actual results could differ from these estimates. The most significant areas that require management judgment are the estimate of unpaid losses and loss adjustment expenses (LAE), evaluation of reinsurance recoverables, recognition of premium revenue, deferred income taxes, valuation of investments, and the valuation of goodwill and intangible assets.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2015
Fair Value of Financial Instruments [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments
	The carrying value and the estimated fair value of the Company’s financial instruments were as follows:
			March 31, 2015				December 31, 2014
			Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
			(in millions)
	Financial assets
	Investments		$	2,541.70	$	2,541.70	$	2,448.40	$	2,448.40
	Cash and cash equivalents		45.6		45.6		103.6		103.6
	Restricted cash and cash equivalents		8.4		8.4		10.8		10.8
	Financial liabilities
	Notes payable		92		97.8		92		97.8
	The Company's estimates of fair value for financial liabilities are based on a combination of the variable interest rates for the Company's existing line of credit and other notes with similar durations to discount the projection of future payments on notes payable. The fair value measurements for notes payable have been determined to be Level 2, as defined below.
	Assets and liabilities recorded at fair value on the consolidated balance sheets are categorized based upon the levels of judgment associated with the inputs used to measure their fair value. Level inputs are defined as follows:
	•	Level 1 - Inputs are unadjusted quoted market prices for identical assets or liabilities in active markets at the measurement date.
	•	Level 2 - Inputs other than Level 1 prices that are observable for similar assets or liabilities through corroboration with market data at the measurement date.
	•	Level 3 - Inputs that are unobservable that reflect management's best estimate of what willing market participants would use in pricing the assets or liabilities at the measurement date.
	Fair values of available-for-sale fixed maturity and equity securities are based on quoted market prices, where available. If quoted market prices and an estimate determined by using objectively verifiable information are unavailable, the Company produces an estimate of fair value based on internally developed valuation techniques, which, depending on the level of observable market inputs, will render the fair value estimate as Level 2 or Level 3. The Company bases all of its estimates of fair value for assets on the bid price as it represents what a third-party market participant would be willing to pay in an arm's length transaction.
	These methods of valuation will only produce an estimate of fair value if there is objectively verifiable information to produce a valuation. If objectively verifiable information is not available, the Company would be required to produce an estimate of fair value using some of the same methodologies, making assumptions for market-based inputs that are unavailable.
	The following table presents the items on the accompanying consolidated balance sheets that are stated at fair value and the corresponding fair value measurements.
			March 31, 2015						December 31, 2014
			Level 1		Level 2		Level 3		Level 1		Level 2		Level 3
			(in millions)
	Fixed maturity securities
	U.S. Treasuries		$	—	$	160.4	$	—	$	—	$	166.7	$	—
	U.S. Agencies		—		38.5		—		—		39.6		—
	States and municipalities		—		813.4		—		—		745.8		—
	Corporate securities		—		914.7		—		—		908.3		—
	Residential mortgage-backed securities		—		294.3		—		—		288.4		—
	Commercial mortgage-backed securities		—		71.2		—		—		65.4		—
	Asset-backed securities		—		67.6		—		—		61.5		—
	Total fixed maturity securities		—		2,360.10		—		—		2,275.70		—
	Equity securities		172.6		—		—		172.7		—		—
	Short-term investments		$	—	$	9	$	—	$	—	$	—	$	—

Investments

Investments	3 Months Ended
	Mar. 31, 2015
Investments [Abstract]
Investments	Investments
	The cost or amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of the Company’s investments were as follows:
			Cost or Amortized			Gross			Gross				Estimated
			Cost			Unrealized			Unrealized				Fair Value
						Gains			Losses
			(in millions)
	At March 31, 2015
	Fixed maturity securities
	U.S. Treasuries		$	153.6		$	6.8		$	—			$	160.4
	U.S. Agencies		36.2			2.3			—				38.5
	States and municipalities		768.1			45.5			(0.2		)		813.4
	Corporate securities		878.1			37.7			(1.1		)		914.7
	Residential mortgage-backed securities		282.5			12			(0.2		)		294.3
	Commercial mortgage-backed securities		70.3			1			(0.1		)		71.2
	Asset-backed securities		67.6			0.1			(0.1		)		67.6
	Total fixed maturity securities		2,256.40			105.4			(1.7		)		2,360.10
	Equity securities		98.9			75			(1.3		)		172.6
	Short-term investments		9			—			—				9
	Total investments		$	2,364.30		$	180.4		$	(3.0	)		$	2,541.70
	At December 31, 2014
	Fixed maturity securities
	U.S. Treasuries		$	160.9		$	5.8		$	—			$	166.7
	U.S. Agencies		37.2			2.4			—				39.6
	States and municipalities		701.6			44.4			(0.2		)		745.8
	Corporate securities		880.7			30.8			(3.2		)		908.3
	Residential mortgage-backed securities		278.6			10.6			(0.8		)		288.4
	Commercial mortgage-backed securities		65.5			0.5			(0.6		)		65.4
	Asset-backed securities		61.6			—			(0.1		)		61.5
	Total fixed maturity securities		2,186.10			94.5			(4.9		)		2,275.70
	Equity securities		97.8			75.5			(0.6		)		172.7
	Total investments		$	2,283.90		$	170		$	(5.5	)		$	2,448.40
	The amortized cost and estimated fair value of fixed maturity securities at March 31, 2015, by contractual maturity, are shown below. Expected maturities differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.
			Amortized Cost			Estimated Fair Value
			(in millions)
	Due in one year or less		$	165.2		$	167.2
	Due after one year through five years		798.6			836
	Due after five years through ten years		619.5			653.3
	Due after ten years		252.6			270.4
	Mortgage and asset-backed securities		420.5			433.2
	Total		$	2,256.40		$	2,360.10
	The following is a summary of investments that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for 12 months or greater as of March 31, 2015 and December 31, 2014.
			March 31, 2015									December 31, 2014
			Estimated Fair Value			Gross Unrealized Losses			Number of Issues			Estimated Fair Value			Gross Unrealized Losses			Number of Issues
			(in millions, except number of issues data)
	Less than 12 months:
	Fixed maturity securities
	States and municipalities		$	36.9		$	(0.2	)	8			$	20.6		$	(0.2	)	5
	Corporate securities		59.8			(0.5		)	27			109.9			(0.8		)	42
	Residential mortgage-backed securities		25.8			(0.1		)	10			—			—			—
	Commercial mortgage-backed securities		10.3			(0.1		)	4			—			—			—
	Total fixed maturity securities		132.8			(0.9		)	49			130.5			(1.0		)	47
	Equity securities		20.2			(1.2		)	30			10.1			(0.6		)	15
	Total less than 12 months		$	153		$	(2.1	)	79			$	140.6		$	(1.6	)	62
	12 months or greater:
	Fixed maturity securities
	Corporate securities		$	46		$	(0.6	)	15			$	129.4		$	(2.4	)	39
	Residential mortgage-backed securities		9.8			(0.1		)	27			44.1			(0.8		)	36
	Commercial mortgage-backed securities		—			—			—			31.3			(0.6		)	8
	Asset-backed securities		19.9			(0.1		)	6			18.3			(0.1		)	6
	Total fixed maturity securities		75.7			(0.8		)	48			223.1			(3.9		)	89
	Equity securities		0.6			(0.1		)	2			—			—			—
	Total 12 months or greater		$	76.3		$	(0.9	)	50			$	223.1		$	(3.9	)	89
	Total available-for-sale:
	Fixed maturity securities
States and municipalities		$	36.9		$	(0.2	)	8			$	20.6		$	(0.2	)	5
Corporate securities		105.8			(1.1		)	42			239.3			(3.2		)	81
Residential mortgage-backed securities		35.6			(0.2		)	37			44.1			(0.8		)	36
Commercial mortgage-backed securities		10.3			(0.1		)	4			31.3			(0.6		)	8
Asset-backed securities		19.9			(0.1		)	6			18.3			(0.1		)	6
Total fixed maturity securities		208.5			(1.7		)	97			353.6			(4.9		)	136
Equity securities		20.8			(1.3		)	32			10.1			(0.6		)	15
Total available-for-sale		$	229.3		$	(3.0	)	129			$	363.7		$	(5.5	)	151
Based on reviews of the fixed maturity securities, the Company determined that unrealized losses for the three months ended March 31, 2015 were primarily the result of changes in prevailing interest rates and not the credit quality of the issuers. The fixed maturity securities whose total fair value was less than amortized cost were not determined to be other-than-temporarily impaired given the severity and duration of the impairment, the credit quality of the issuers, the Company’s intent to not sell the securities, and a determination that it is not more likely than not that the Company will be required to sell the securities until fair value recovers to above amortized cost, or maturity.
Based on reviews of the equity securities for the three months ended March 31, 2015, the Company determined that the unrealized losses as of that date were not considered to be other-than-temporary due to the financial condition and near-term prospects of the issuers.
Net realized gains on investments and the change in unrealized gains (losses) on fixed maturity and equity securities are determined on a specific-identification basis and were as follows:
		Three Months Ended
		March 31,
		2015			2014
	(in millions)
Net realized gains on investments
Fixed maturity securities
Gross gains		$	—		$	0.8
Gross losses		—			—
Net realized gains on fixed maturity securities		$	—		$	0.8
Equity securities
Gross gains		$	1.5		$	2.5
Gross losses		(0.3		)	—
Net realized gains on equity securities		$	1.2		$	2.5
Total		$	1.2		$	3.3
Change in unrealized gains (losses)
Fixed maturity securities		$	14.1		$	13.3
Equity securities		(1.2		)	(0.8		)
Total		$	12.9		$	12.5
Net investment income was as follows:
		Three Months Ended
		March 31,
		2015			2014
	(in millions)
Fixed maturity securities		$	16.4		$	17.6
Equity securities		1.1			1
Cash equivalents and restricted cash		—			—
		17.5			18.6
Investment expenses		(0.6		)	(0.6		)
Net investment income		$	16.9		$	18
The Company is required by various state laws and regulations to keep securities or letters of credit in depository accounts with certain states in which it does business. As of March 31, 2015 and December 31, 2014, securities having a fair value of $917.3 million and $783.9 million, respectively, were on deposit. These laws and regulations govern not only the amount, but also the types of securities that are eligible for deposit. The deposits are limited to fixed maturity securities in all states. Additionally, certain reinsurance contracts require Company funds to be held in trust for the benefit of the ceding reinsurer to secure the outstanding liabilities assumed by the Company. The fair value of fixed maturity securities held in trust for the benefit of ceding reinsurers at March 31, 2015 and December 31, 2014 was $31.3 million and $31.2 million, respectively. Pursuant to the Third Amended and Restated Credit Agreement with Wells Fargo (Amended Credit Facility), a portion of the Company's debt was secured by fixed maturity securities and restricted cash and cash equivalents that had a fair value of $74.0 million and $74.6 million at March 31, 2015 and December 31, 2014, respectively.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Taxes [Abstract]
Income Taxes	Income Taxes
	Income tax expense for interim periods is measured using an estimated effective tax rate for the annual period. The following is a reconciliation of the federal statutory income tax rate to the Company’s effective tax rates for the periods presented.
		Three Months Ended
		March 31,
		2015		2014
	Expense computed at statutory rate	35	%	35	%
	Dividends received deduction and tax-exempt interest	(8.8	)	(16.0	)
	LPT deferred gain amortization	(4.2	)	(8.5	)
	LPT reserve adjustment	—		(0.4	)
	Other	0.5		0.8
	Effective tax rate	22.5	%	10.9	%

Liability_for_Unpaid_Losses_an

Liability for Unpaid Losses and Loss Adjustment Expenses	3 Months Ended
	Mar. 31, 2015
Liability for Unpaid Losses and Loss Adjustment Expenses [Abstract]
Liability for Unpaid Losses and Loss Adjustment Expenses	Liability for Unpaid Losses and Loss Adjustment Expenses
	The following table represents a reconciliation of changes in the liability for unpaid losses and LAE.
		Three Months Ended
		March 31,
		2015		2014
		(in millions)
	Unpaid losses and LAE, gross of reinsurance, at beginning of period	$	2,369.70	$	2,330.50
	Less reinsurance recoverable, excluding bad debt allowance, on unpaid losses and LAE	669.5		743.1
	Net unpaid losses and LAE at beginning of period	1,700.20		1,587.40
	Losses and LAE, net of reinsurance, related to:
	Current period	107.7		124.8
	Prior periods	1.7		1.8
	Total net losses and LAE incurred during the period	109.4		126.6
	Paid losses and LAE, net of reinsurance, related to:
	Current period	4.2		4.5
	Prior periods	98.1		87.1
	Total net paid losses and LAE during the period	102.3		91.6
	Ending unpaid losses and LAE, net of reinsurance	1,707.30		1,622.40
	Reinsurance recoverable, excluding bad debt allowance, on unpaid losses and LAE	663		735.8
	Unpaid losses and LAE, gross of reinsurance, at end of period	$	2,370.30	$	2,358.20
	Total net losses and LAE included in the above table excludes the impact of the aggregate of the amortization of the deferred reinsurance gain—LPT Agreement, LPT Reserve Adjustments, and LPT Contingent Commission Adjustments, which totaled $3.1 million and $4.3 million for the three months ended March 31, 2015 and 2014, respectively (Note 6).
	The increase in the estimates of incurred losses and LAE attributable to insured events for prior periods was related to the Company's assigned risk business.

LPT_Agreement

LPT Agreement	3 Months Ended
	Mar. 31, 2015
LPT Agreement [Abstract]
LPT Agreement	LPT Agreement
	The Company is party to a 100% quota share retroactive reinsurance agreement (LPT Agreement) under which $1.5 billion in liabilities for losses and LAE related to claims incurred by EICN prior to July 1, 1995 were reinsured for consideration of $775.0 million. The LPT Agreement provides coverage up to $2.0 billion. The initial Deferred Gain resulting from the LPT Agreement was recorded as a liability in the accompanying consolidated balance sheets as Deferred reinsurance gain–LPT Agreement. The Company is also entitled to receive a contingent profit commission under the LPT Agreement. The contingent profit commission is an amount based on the favorable difference between actual paid losses and LAE and expected paid losses and LAE as established in the LPT Agreement. The Company records its estimate of contingent profit commission in the accompanying consolidated balance sheets as Contingent commission receivable–LPT Agreement and a corresponding liability is recorded on the accompanying consolidated balance sheets in Deferred reinsurance gain–LPT Agreement. The Deferred Gain is being amortized using the recovery method. Amortization is determined by the proportion of actual reinsurance recoveries to total estimated recoveries over the life of the LPT Agreement, except for the contingent profit commission, which is amortized through June 30, 2024. The amortization is recorded in losses and LAE incurred in the accompanying consolidated statements of comprehensive income. Any adjustments to the Deferred Gain are recorded in losses and LAE incurred in the accompanying consolidated statements of comprehensive income.
	The Company amortized $2.9 million and $3.3 million of the Deferred Gain for the three months ended March 31, 2015 and 2014, respectively. Additionally, the Deferred Gain was reduced by $0.7 million for the three months ended March 31, 2014 due to a favorable LPT Reserve Adjustment and by $0.2 million and $0.3 million for the three months ended March 31, 2015 and 2014, respectively, due to favorable LPT Contingent Commission Adjustments. The remaining Deferred Gain was $204.1 million and $207.0 million as of March 31, 2015 and December 31, 2014, respectively. The estimated remaining liabilities subject to the LPT Agreement were $527.9 million and $534.8 million as of March 31, 2015 and December 31, 2014, respectively. Losses and LAE paid with respect to the LPT Agreement totaled $675.2 million and $668.4 million from inception through March 31, 2015 and December 31, 2014, respectively.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2015
Accumulated Other Comprehensive Income [Abstract]
Accumulated Other Comprehensive Income, Net	Accumulated Other Comprehensive Income, net
	Accumulated other comprehensive income, net, is comprised of unrealized gains on investments classified as available-for-sale, net of deferred tax expense. The following table summarizes the components of accumulated other comprehensive income, net:
		March 31, 2015			December 31, 2014
		(in millions)
	Net unrealized gain on investments, before taxes	$	177.4		$	164.5
	Deferred tax expense on net unrealized gains	(62.1		)	(57.6		)
	Total accumulated other comprehensive income, net	$	115.3		$	106.9

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2015
Stock-Based Compensation [Abstract]
Stock-Based compensation	Stock-Based Compensation
	The Company awarded stock options, restricted stock units (RSUs) and performance share units (PSUs) to certain officers of the Company as follows:
		Number Awarded	Weighted Average Fair Value on Date of Grant		Weighted Average Exercise Price		Aggregate Fair Value on Date of Grant
							(in millions)
	Mar-15
	Stock options(1)	80,800	$	7.63	$	24.2	$	0.6
	RSUs(1)	89,602	24.2		—		2.2
	PSUs(2)	110,000	24.2		—		2.7
	-1	The stock options and RSUs awarded in March 2015 were awarded to certain officers of the Company and vest 25% on March 15, 2016, and each of the subsequent three anniversaries of that date. The stock options and RSUs are subject to accelerated vesting in certain circumstances, including but not limited to: death, disability, retirement, or in connection with change of control of the Company. The stock options expire seven years from the date of grant.
	-2	The PSUs awarded in March 2015 were awarded to certain officers of the Company and have a performance period of two years followed by an additional one year vesting period. The PSU awards are subject to certain performance goals with payouts that range from 0% to 200% of the target awards. The value shown in the table represents the aggregate number of PSUs awarded at the target level.
	A total of 131,056 and 120,494 stock options were exercised during the three months ended March 31, 2015 and the year ended December 31, 2014, respectively.

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share
	Basic earnings per share excludes dilution and is computed by dividing income applicable to stockholders by the weighted average number of shares outstanding for the period. Diluted earnings per share reflects the potential dilutive impact of all convertible securities on earnings per share. Diluted earnings per share includes shares assumed issued under the “treasury stock method,” which reflects the potential dilution that would occur if outstanding options were to be exercised. The following table presents the net income and the weighted average number of shares outstanding used in the earnings per common share calculations.
		Three Months Ended
		March 31,
		2015			2014
		(in millions, except share data)
	Net income available to stockholders—basic and diluted	$	14		$	10.8
	Weighted average number of shares outstanding—basic	31,740,923			31,409,322
	Effect of dilutive securities:
	PSUs	322,850			214,121
	Stock options	310,899			277,376
	RSUs	79,392			89,151
	Dilutive potential shares	713,141			580,648
	Weighted average number of shares outstanding—diluted	32,454,064			31,989,970
	Diluted earnings per share excludes outstanding options and other common stock equivalents in periods where the inclusion of such options and common stock equivalents would be anti-dilutive. The following table presents options and RSUs that were excluded from diluted earnings per share.
		Three Months Ended
		March 31,
		2015		2014
	Options and RSUs excluded under the treasury method as the potential proceeds on settlement or exercise price were greater than the value of shares acquired	267,444		296,844

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value of Financial Instruments [Abstract]
Estimated fair value of financial instruments table	The carrying value and the estimated fair value of the Company’s financial instruments were as follows:
		March 31, 2015				December 31, 2014
		Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
		(in millions)
	Financial assets
	Investments	$	2,541.70	$	2,541.70	$	2,448.40	$	2,448.40
	Cash and cash equivalents	45.6		45.6		103.6		103.6
	Restricted cash and cash equivalents	8.4		8.4		10.8		10.8
	Financial liabilities
	Notes payable	92		97.8		92		97.8
Fair value, assets and liabilities measured on recurring basis table	The following table presents the items on the accompanying consolidated balance sheets that are stated at fair value and the corresponding fair value measurements.
		March 31, 2015						December 31, 2014
		Level 1		Level 2		Level 3		Level 1		Level 2		Level 3
		(in millions)
	Fixed maturity securities
	U.S. Treasuries	$	—	$	160.4	$	—	$	—	$	166.7	$	—
	U.S. Agencies	—		38.5		—		—		39.6		—
	States and municipalities	—		813.4		—		—		745.8		—
	Corporate securities	—		914.7		—		—		908.3		—
	Residential mortgage-backed securities	—		294.3		—		—		288.4		—
	Commercial mortgage-backed securities	—		71.2		—		—		65.4		—
	Asset-backed securities	—		67.6		—		—		61.5		—
	Total fixed maturity securities	—		2,360.10		—		—		2,275.70		—
	Equity securities	172.6		—		—		172.7		—		—
	Short-term investments	$	—	$	9	$	—	$	—	$	—	$	—

Investments_Tables

Investments (Tables)	3 Months Ended
	Mar. 31, 2015
Investments [Abstract]
Available-for-sale securities table	The cost or amortized cost, gross unrealized gains, gross unrealized losses, and estimated fair value of the Company’s investments were as follows:
			Cost or Amortized			Gross			Gross				Estimated
			Cost			Unrealized			Unrealized				Fair Value
						Gains			Losses
			(in millions)
	At March 31, 2015
	Fixed maturity securities
	U.S. Treasuries		$	153.6		$	6.8		$	—			$	160.4
	U.S. Agencies		36.2			2.3			—				38.5
	States and municipalities		768.1			45.5			(0.2		)		813.4
	Corporate securities		878.1			37.7			(1.1		)		914.7
	Residential mortgage-backed securities		282.5			12			(0.2		)		294.3
	Commercial mortgage-backed securities		70.3			1			(0.1		)		71.2
	Asset-backed securities		67.6			0.1			(0.1		)		67.6
	Total fixed maturity securities		2,256.40			105.4			(1.7		)		2,360.10
	Equity securities		98.9			75			(1.3		)		172.6
	Short-term investments		9			—			—				9
	Total investments		$	2,364.30		$	180.4		$	(3.0	)		$	2,541.70
	At December 31, 2014
	Fixed maturity securities
	U.S. Treasuries		$	160.9		$	5.8		$	—			$	166.7
	U.S. Agencies		37.2			2.4			—				39.6
	States and municipalities		701.6			44.4			(0.2		)		745.8
	Corporate securities		880.7			30.8			(3.2		)		908.3
	Residential mortgage-backed securities		278.6			10.6			(0.8		)		288.4
	Commercial mortgage-backed securities		65.5			0.5			(0.6		)		65.4
	Asset-backed securities		61.6			—			(0.1		)		61.5
	Total fixed maturity securities		2,186.10			94.5			(4.9		)		2,275.70
	Equity securities		97.8			75.5			(0.6		)		172.7
	Total investments		$	2,283.90		$	170		$	(5.5	)		$	2,448.40
Investments classified by contractual maturity date table	The amortized cost and estimated fair value of fixed maturity securities at March 31, 2015, by contractual maturity, are shown below. Expected maturities differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties.
			Amortized Cost			Estimated Fair Value
			(in millions)
	Due in one year or less		$	165.2		$	167.2
	Due after one year through five years		798.6			836
	Due after five years through ten years		619.5			653.3
	Due after ten years		252.6			270.4
	Mortgage and asset-backed securities		420.5			433.2
	Total		$	2,256.40		$	2,360.10
Unrealized loss on investments table	The following is a summary of investments that have been in a continuous unrealized loss position for less than 12 months and those that have been in a continuous unrealized loss position for 12 months or greater as of March 31, 2015 and December 31, 2014.
			March 31, 2015									December 31, 2014
			Estimated Fair Value			Gross Unrealized Losses			Number of Issues			Estimated Fair Value			Gross Unrealized Losses			Number of Issues
			(in millions, except number of issues data)
	Less than 12 months:
	Fixed maturity securities
	States and municipalities		$	36.9		$	(0.2	)	8			$	20.6		$	(0.2	)	5
	Corporate securities		59.8			(0.5		)	27			109.9			(0.8		)	42
	Residential mortgage-backed securities		25.8			(0.1		)	10			—			—			—
	Commercial mortgage-backed securities		10.3			(0.1		)	4			—			—			—
	Total fixed maturity securities		132.8			(0.9		)	49			130.5			(1.0		)	47
	Equity securities		20.2			(1.2		)	30			10.1			(0.6		)	15
	Total less than 12 months		$	153		$	(2.1	)	79			$	140.6		$	(1.6	)	62
	12 months or greater:
	Fixed maturity securities
	Corporate securities		$	46		$	(0.6	)	15			$	129.4		$	(2.4	)	39
	Residential mortgage-backed securities		9.8			(0.1		)	27			44.1			(0.8		)	36
	Commercial mortgage-backed securities		—			—			—			31.3			(0.6		)	8
	Asset-backed securities		19.9			(0.1		)	6			18.3			(0.1		)	6
	Total fixed maturity securities		75.7			(0.8		)	48			223.1			(3.9		)	89
	Equity securities		0.6			(0.1		)	2			—			—			—
	Total 12 months or greater		$	76.3		$	(0.9	)	50			$	223.1		$	(3.9	)	89
	Total available-for-sale:
	Fixed maturity securities
	States and municipalities		$	36.9		$	(0.2	)	8			$	20.6		$	(0.2	)	5
	Corporate securities		105.8			(1.1		)	42			239.3			(3.2		)	81
	Residential mortgage-backed securities		35.6			(0.2		)	37			44.1			(0.8		)	36
	Commercial mortgage-backed securities		10.3			(0.1		)	4			31.3			(0.6		)	8
	Asset-backed securities		19.9			(0.1		)	6			18.3			(0.1		)	6
	Total fixed maturity securities		208.5			(1.7		)	97			353.6			(4.9		)	136
	Equity securities		20.8			(1.3		)	32			10.1			(0.6		)	15
	Total available-for-sale		$	229.3		$	(3.0	)	129			$	363.7		$	(5.5	)	151
Net realized gains and change in unrealized gains (losses), available for sale securities table	ealized gains on investments and the change in unrealized gains (losses) on fixed maturity and equity securities are determined on a specific-identification basis and were as follows:
			Three Months Ended
			March 31,
			2015			2014
		(in millions)
	Net realized gains on investments
	Fixed maturity securities
	Gross gains		$	—		$	0.8
	Gross losses		—			—
	Net realized gains on fixed maturity securities		$	—		$	0.8
	Equity securities
	Gross gains		$	1.5		$	2.5
	Gross losses		(0.3		)	—
	Net realized gains on equity securities		$	1.2		$	2.5
	Total		$	1.2		$	3.3
	Change in unrealized gains (losses)
	Fixed maturity securities		$	14.1		$	13.3
	Equity securities		(1.2		)	(0.8		)
	Total		$	12.9		$	12.5
Investment income table	Net investment income was as follows:
			Three Months Ended
			March 31,
			2015			2014
		(in millions)
	Fixed maturity securities		$	16.4		$	17.6
	Equity securities		1.1			1
	Cash equivalents and restricted cash		—			—
			17.5			18.6
	Investment expenses		(0.6		)	(0.6		)
	Net investment income		$	16.9		$	18

Income_Taxes_Tables

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2015
Income Taxes [Abstract]
Reconciliation of federal staturoty income tax rates to the effective tax rates table	The following is a reconciliation of the federal statutory income tax rate to the Company’s effective tax rates for the periods presented.
		Three Months Ended
		March 31,
		2015		2014
	Expense computed at statutory rate	35	%	35	%
	Dividends received deduction and tax-exempt interest	(8.8	)	(16.0	)
	LPT deferred gain amortization	(4.2	)	(8.5	)
	LPT reserve adjustment	—		(0.4	)
	Other	0.5		0.8
	Effective tax rate	22.5	%	10.9	%

Liability_for_Unpaid_Losses_an1

Liability for Unpaid Losses and Loss Adjustment Expenses (Tables)	3 Months Ended
	Mar. 31, 2015
Liability for Unpaid Losses and Loss Adjustment Expenses [Abstract]
Changes in the liability for unpaid losses and LAE table	The following table represents a reconciliation of changes in the liability for unpaid losses and LAE.
		Three Months Ended
		March 31,
		2015		2014
		(in millions)
	Unpaid losses and LAE, gross of reinsurance, at beginning of period	$	2,369.70	$	2,330.50
	Less reinsurance recoverable, excluding bad debt allowance, on unpaid losses and LAE	669.5		743.1
	Net unpaid losses and LAE at beginning of period	1,700.20		1,587.40
	Losses and LAE, net of reinsurance, related to:
	Current period	107.7		124.8
	Prior periods	1.7		1.8
	Total net losses and LAE incurred during the period	109.4		126.6
	Paid losses and LAE, net of reinsurance, related to:
	Current period	4.2		4.5
	Prior periods	98.1		87.1
	Total net paid losses and LAE during the period	102.3		91.6
	Ending unpaid losses and LAE, net of reinsurance	1,707.30		1,622.40
	Reinsurance recoverable, excluding bad debt allowance, on unpaid losses and LAE	663		735.8
	Unpaid losses and LAE, gross of reinsurance, at end of period	$	2,370.30	$	2,358.20

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2015
Accumulated Other Comprehensive Income [Abstract]
Schedule of accumulated other comprehensive income (loss) table	The following table summarizes the components of accumulated other comprehensive income, net:
		March 31, 2015			December 31, 2014
		(in millions)
	Net unrealized gain on investments, before taxes	$	177.4		$	164.5
	Deferred tax expense on net unrealized gains	(62.1		)	(57.6		)
	Total accumulated other comprehensive income, net	$	115.3		$	106.9

StockBased_Compensation_StockB

Stock-Based Compensation Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Stock-Based Compensation [Abstract]
Share-based compensation arrangements by share-based payment award table	The Company awarded stock options, restricted stock units (RSUs) and performance share units (PSUs) to certain officers of the Company as follows:
		Number Awarded	Weighted Average Fair Value on Date of Grant		Weighted Average Exercise Price		Aggregate Fair Value on Date of Grant
							(in millions)
	Mar-15
	Stock options(1)	80,800	$	7.63	$	24.2	$	0.6
	RSUs(1)	89,602	24.2		—		2.2
	PSUs(2)	110,000	24.2		—		2.7
	-1	The stock options and RSUs awarded in March 2015 were awarded to certain officers of the Company and vest 25% on March 15, 2016, and each of the subsequent three anniversaries of that date. The stock options and RSUs are subject to accelerated vesting in certain circumstances, including but not limited to: death, disability, retirement, or in connection with change of control of the Company. The stock options expire seven years from the date of grant.
	-2	The PSUs awarded in March 2015 were awarded to certain officers of the Company and have a performance period of two years followed by an additional one year vesting period. The PSU awards are subject to certain performance goals with payouts that range from 0% to 200% of the target awards. The value shown in the table represents the aggregate number of PSUs awarded at the target level.

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Net income and weighted average common shares outstanding used in earnings per share calculations table	The following table presents the net income and the weighted average number of shares outstanding used in the earnings per common share calculations.
		Three Months Ended
		March 31,
		2015			2014
		(in millions, except share data)
	Net income available to stockholders—basic and diluted	$	14		$	10.8
	Weighted average number of shares outstanding—basic	31,740,923			31,409,322
	Effect of dilutive securities:
	PSUs	322,850			214,121
	Stock options	310,899			277,376
	RSUs	79,392			89,151
	Dilutive potential shares	713,141			580,648
	Weighted average number of shares outstanding—diluted	32,454,064			31,989,970
Antidilutive securities excluded from computation of earnings per share table	The following table presents options and RSUs that were excluded from diluted earnings per share.
		Three Months Ended
		March 31,
		2015		2014
	Options and RSUs excluded under the treasury method as the potential proceeds on settlement or exercise price were greater than the value of shares acquired	267,444		296,844

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	$2,541,700	$2,448,400
Investments, fair value	2,541,700	2,448,400
Cash and cash equivalents	45,600	103,600	51,100	34,500
Cash and cash equivalents, estimated fair value	45,600	103,600
Restricted cash and cash equivalents	8,400	10,800
Notes payable	92,000	92,000
Notes Payable, fair value	97,800	97,800
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments	31,300	31,200
Restricted cash and cash equivalents	$8,400	$10,800

Fair_Value_of_Financial_Instru3

Fair Value of Financial Instruments, Fair Value Inputs (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	$2,541,700	$2,448,400
Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,360,100	2,275,700
Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,360,100	2,275,700
Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	160,400	166,700
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		166,700
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
US Government Agencies Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	38,500	39,600
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		39,600
US Government Agencies Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
US States and Political Subdivisions Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	813,400	745,800
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		745,800
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	914,700	908,300
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		908,300
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	294,300	288,400
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		288,400
Residential Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	71,200	65,400
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		65,400
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	67,600	61,500
Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		61,500
Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	172,600	172,700
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments		172,705
Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Short-term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Short-term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	9,000	0
Short-term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	$0	$0

Investments_Details

Investments (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$2,364,300	$2,283,900
Gross unrealized gain	180,400	170,000
Gross unrealized loss	-3,000	-5,500
Investments	2,541,700	2,448,400
Deposit Assets
Investments	2,541,700	2,448,400
Assets Held-in-trust
Investments	2,541,700	2,448,400
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	2,256,400	2,186,100
Gross unrealized gain	105,400	94,500
Gross unrealized loss	-1,700	-4,900
Investments	2,360,100	2,275,700
Deposit Assets
Investments	2,360,100	2,275,700
Assets Held-in-trust
Investments	2,360,100	2,275,700
US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	153,600	160,900
Gross unrealized gain	6,800	5,800
Gross unrealized loss	0	0
Investments	160,400	166,700
Deposit Assets
Investments	160,400	166,700
Assets Held-in-trust
Investments	160,400	166,700
US Government Agencies Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	36,200	37,200
Gross unrealized gain	2,300	2,400
Gross unrealized loss	0	0
Investments	38,500	39,600
Deposit Assets
Investments	38,500	39,600
Assets Held-in-trust
Investments	38,500	39,600
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	768,100	701,600
Gross unrealized gain	45,500	44,400
Gross unrealized loss	-200	-200
Investments	813,400	745,800
Deposit Assets
Investments	813,400	745,800
Assets Held-in-trust
Investments	813,400	745,800
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	878,100	880,700
Gross unrealized gain	37,700	30,800
Gross unrealized loss	-1,100	-3,200
Investments	914,700	908,300
Deposit Assets
Investments	914,700	908,300
Assets Held-in-trust
Investments	914,700	908,300
Residential Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	282,500	278,600
Gross unrealized gain	12,000	10,600
Gross unrealized loss	-200	-800
Investments	294,300	288,400
Deposit Assets
Investments	294,300	288,400
Assets Held-in-trust
Investments	294,300	288,400
Commercial Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	70,300	65,500
Gross unrealized gain	1,000	500
Gross unrealized loss	-100	-600
Investments	71,200	65,400
Deposit Assets
Investments	71,200	65,400
Assets Held-in-trust
Investments	71,200	65,400
Asset-backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	67,600	61,600
Gross unrealized gain	100	0
Gross unrealized loss	-100	-100
Investments	67,600	61,500
Deposit Assets
Investments	67,600	61,500
Assets Held-in-trust
Investments	67,600	61,500
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	98,900	97,800
Gross unrealized gain	75,000	75,500
Gross unrealized loss	-1,300	-600
Investments	172,600	172,700
Deposit Assets
Investments	172,600	172,700
Assets Held-in-trust
Investments	172,600	172,700
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	9,000
Gross unrealized gain	0
Gross unrealized loss	0
Fair Value Measurement [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments	31,300	31,200
Deposit Assets
Investments	31,300	31,200
Assets Held-in-trust
Investments	31,300	31,200
Fair Value Measurement [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments	917,300	783,900
Deposit Assets
Investments	917,300	783,900
Assets Held-in-trust
Investments	917,300	783,900
Fair Value Measurement [Member] | Fixed Maturities and Restricted Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments	74,000	74,600
Deposit Assets
Investments	74,000	74,600
Assets Held-in-trust
Investments	$74,000	$74,600

Investments_Amortized_Cost_and

Investments, Amortized Cost and Estimated Fair Value (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Amortized Cost
Due in one year or less, amortized cost	$165,200
Due after one year through five years, amortized cost	798,600
Due after five years through ten years, amortized cost	619,500
Due after ten years, amortized cost	252,600
Mortgage and asset-backed securities, amortized cost	420,500
Total, amortized cost	2,256,400
Estimated Fair Value
Due in one year or less, fair value	167,200
Due after one year through five years, fair value	836,000
Due after five years through ten years, fair value	653,300
Due after ten years, fair value	270,400
Mortgage and asset-backed securities, fair value	433,200
Total, fair value	$2,360,100	$2,275,700

Investments_Continuous_Loss_Po

Investments, Continuous Loss Position (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Estimated Fair Value
Estimated fair value, less than 12 months	$153,000,000	$140,600,000
Estimated fair value, 12 months or greater	76,300,000	223,100,000
Estimated fair value, total	229,300,000	363,700,000
Gross Unrealized Losses
Gross unrealized losses, less than 12 months	-2,100,000	-1,600,000
Gross unrealized losses, 12 months or greater	900,000	3,900,000
Estimated unrealized losses, total	-3,000,000	-5,500,000
Number of issues in loss position, less than 12 months	79	62
Number of Issues in loss position, 12 months or greater	50	89
Number of issues loss position, aggregate	129	151
Debt Securities [Member]
Estimated Fair Value
Estimated fair value, less than 12 months	132,800,000	130,500,000
Estimated fair value, 12 months or greater	75,700,000	223,100,000
Estimated fair value, total	208,500,000	353,600,000
Gross Unrealized Losses
Gross unrealized losses, less than 12 months	-900,000	-1,000,000
Gross unrealized losses, 12 months or greater	800,000	3,900,000
Estimated unrealized losses, total	-1,700,000	-4,900,000
Number of issues in loss position, less than 12 months	49	47
Number of Issues in loss position, 12 months or greater	48	89
Number of issues loss position, aggregate	97	136
US States and Political Subdivisions Debt Securities [Member]
Estimated Fair Value
Estimated fair value, less than 12 months	36,900,000	20,600,000
Estimated fair value, total	36,900,000	20,600,000
Gross Unrealized Losses
Gross unrealized losses, less than 12 months	-200,000	-200,000
Estimated unrealized losses, total	-200,000	-200,000
Number of issues in loss position, less than 12 months	8	5
Number of issues loss position, aggregate	8	5
Corporate Debt Securities [Member]
Estimated Fair Value
Estimated fair value, less than 12 months	59,800,000	109,900,000
Estimated fair value, 12 months or greater	46,000,000	129,400,000
Estimated fair value, total	105,800,000	239,300,000
Gross Unrealized Losses
Gross unrealized losses, less than 12 months	-500,000	-800,000
Gross unrealized losses, 12 months or greater	600,000	2,400,000
Estimated unrealized losses, total	-1,100,000	-3,200,000
Number of issues in loss position, less than 12 months	27	42
Number of Issues in loss position, 12 months or greater	15	39
Number of issues loss position, aggregate	42	81
Residential Mortgage Backed Securities [Member]
Estimated Fair Value
Estimated fair value, less than 12 months	25,800,000	0
Estimated fair value, 12 months or greater	9,800,000	44,100,000
Estimated fair value, total	35,600,000	44,100,000
Gross Unrealized Losses
Gross unrealized losses, less than 12 months	-100,000	0
Gross unrealized losses, 12 months or greater	100,000	800,000
Estimated unrealized losses, total	-200,000	-800,000
Number of issues in loss position, less than 12 months	10	0
Number of Issues in loss position, 12 months or greater	27	36
Number of issues loss position, aggregate	37	36
Commercial Mortgage Backed Securities [Member]
Estimated Fair Value
Estimated fair value, less than 12 months	10,300,000	0
Estimated fair value, 12 months or greater	0	31,300,000
Estimated fair value, total	10,300,000	31,300,000
Gross Unrealized Losses
Gross unrealized losses, less than 12 months	-100,000	0
Gross unrealized losses, 12 months or greater	0	600,000
Estimated unrealized losses, total	-100,000	-600,000
Number of issues in loss position, less than 12 months	4	0
Number of Issues in loss position, 12 months or greater	0	8
Number of issues loss position, aggregate	4	8
Asset-backed Securities [Member]
Estimated Fair Value
Estimated fair value, 12 months or greater	19,900,000	18,300,000
Estimated fair value, total	19,900,000	18,300,000
Gross Unrealized Losses
Gross unrealized losses, 12 months or greater	100,000	100,000
Estimated unrealized losses, total	-100,000	-100,000
Number of Issues in loss position, 12 months or greater	6	6
Number of issues loss position, aggregate	0	0
Equity Securities [Member]
Estimated Fair Value
Estimated fair value, less than 12 months	20,200,000	10,100,000
Estimated fair value, 12 months or greater	600,000	0
Estimated fair value, total	20,800,000	10,100,000
Gross Unrealized Losses
Gross unrealized losses, less than 12 months	-1,200,000	-600,000
Gross unrealized losses, 12 months or greater	100,000	0
Estimated unrealized losses, total	-1,300,000	-600,000
Number of issues in loss position, less than 12 months	30	15
Number of Issues in loss position, 12 months or greater	2	0
Number of issues loss position, aggregate	$32	$15

Investments_Net_Realized_Gains

Investments, Net Realized Gains (Losses) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net realized gains (losses)
Net realized gains (losses) on fixed maturity and equity securities	$1,200	$3,300
Change in unrealized gains (losses)
Change in unrealized gains (losses) on fixed maturity and equity securities	12,900	12,500
Debt Securities [Member]
Net realized gains (losses)
Gross gains from sales	0	800
Gross losses from sales	0	0
Net realized gains (losses) on fixed maturity and equity securities	0	800
Change in unrealized gains (losses)
Change in unrealized gains (losses) on fixed maturity and equity securities	14,100	13,300
Equity Securities [Member]
Net realized gains (losses)
Gross gains from sales	1,500	2,500
Gross losses from sales	300	0
Net realized gains (losses) on fixed maturity and equity securities	1,200	2,500
Change in unrealized gains (losses)
Change in unrealized gains (losses) on fixed maturity and equity securities	($1,200)	($800)

Net_Investment_Income_Details

Net Investment Income (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income	$17,500	$18,600
Investment expenses	600	600
Net investment income	16,900	18,000
Debt Securities [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income related to fixed maturity securities and short-term investments and cash equivalents	16,400	17,600
Equity Securities [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income related to equity securities	1,100	1,000
Short-term Investments [Member]
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Investment income related to fixed maturity securities and short-term investments and cash equivalents	$0	$0

Income_Taxes_Details

Income Taxes (Details)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Expense computed at statutory rate	35.00%	35.00%
Dividends received deduction and tax-exempt interest	-8.80%	-16.00%
LPT deferred gain amortization	-4.20%	-8.50%
LPT reserve adjustment	0.00%	-0.40%
Other	0.50%	0.80%
Effective tax rate	22.50%	10.90%

Liability_for_Unpaid_Losses_an2

Liability for Unpaid Losses and Loss Adjustment Expenses (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Unpaid losses and LAE, gross of reinsurance, at beginning of period	$2,369,700,000	$2,330,500,000
Less reinsurance recoverable, excluding bad debt allowance, on unpaid losses and LAE	669,500,000	743,100,000
Net unpaid losses and LAE at beginning of period	1,700,200,000	1,587,400,000
Losses and LAE, net of reinsurance, related to:
Current period	107,700,000	124,800,000
Prior periods	1,700,000	1,800,000
Total net losses and LAE incurred during the period	109,400,000	126,600,000
Deduct payments for losses and LAE, net of reinsurance, related to:
Current period	4,200,000	4,500,000
Prior periods	98,100,000	87,100,000
Total net paid losses and LAE during the period	102,300,000	91,600,000
Ending unpaid losses and LAE, net of reinsurance	1,707,300,000	1,622,400,000
Reinsurance recoverable, excluding bad debt allowance, on unpaid losses and LAE	663,000,000	735,800,000
Unpaid losses and LAE, gross of reinsurance, at end of period	2,370,300,000	2,358,200,000
LPT Agreement [Abstract]
Impact of the LPT Agreement	$3,100,000		$4,300,000

LPT_Agreement_LPT_Agreement_De

LPT Agreement LPT Agreement (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Reinsurance Agreement [Line Items]
Reinsurance quota share, percentage	100.00%
Liabilities for the incurred but unpaid losses and LAE related to claims prior to July 1, 1995	$1,500,000,000
Ceded premiums written	775,000,000
Amortization of deferred gain	2,900,000	3,300,000
Deferred reinsurance gain—LPT Agreement	204,100,000		207,000,000
Estimated remaining liabilities - LPT Agreement	527,900,000		534,800,000
Paid losses and LAE claims related to LPT	675,200,000		668,400,000
Change Due to Estimated Reserves Ceded Under the LPT Agreement [Member]
Reinsurance Agreement [Line Items]
Amortization of deferred gain		700,000
Change to Contingent Profit Commission [Member]
Reinsurance Agreement [Line Items]
Amortization of deferred gain	200,000	300,000
Indemnification Agreement [Member]
Reinsurance Agreement [Line Items]
Coverage provided under LPT Agreement	$2,000,000,000

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net unrealized gain on investments, before taxes	$177,400	$164,500
Deferred tax expense on net unrealized gains	-62,100	-57,600
Total accumulated other comprehensive income, net	$115,300	$106,900

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	3 Months Ended		12 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-options exercised	131,056		120,494
Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights for options awarded	vest 25% on March 15, 2016, and each of the subsequent three anniversaries of that date
Expiration Period for Options Awarded	seven years
Performance share awards performance period	two years
Performance share awards, minimum payout	0.00%
Performane share awards, maximum payout	200.00%
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation award, shares issued	80,800	[1]
Share-based compensation options, exercise price on grant date	7.63	[1]
Share-based compensation award, fair value assumptions, exercise price	24.2	[1]
Fair value of awards awarded on grant date	0.6	[1]
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation award, shares issued	89,602	[1]
Share-based compensation options, exercise price on grant date	24.2	[2]
Share-based compensation award, fair value assumptions, exercise price	0
Fair value of awards awarded on grant date	2.2	[1]
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation award, shares issued	110,000	[2]
Share-based compensation options, exercise price on grant date	24.2	[2]
Share-based compensation award, fair value assumptions, exercise price	0
Fair value of awards awarded on grant date	2.7	[2]
[1]	The stock options and RSUs awarded in March 2015 were awarded to certain officers of the Company and vest 25% on March 15, 2016, and each of the subsequent three anniversaries of that date. The stock options and RSUs are subject to accelerated vesting in certain circumstances, including but not limited to: death, disability, retirement, or in connection with change of control of the Company. The stock options expire seven years from the date of grant.(2)
[2]	The PSUs awarded in March 2015 were awarded to certain officers of the Company and have a performance period of two years followed by an additional one year vesting period. The PSU awards are subject to certain performance goals with payouts that range from 0% to 200% of the target awards. The value shown in the table represents the aggregate number of PSUs awarded at the target level.

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Net income available to stockholders - basic and diluted	$14,000	$10,800
Weighted average number of shares outstanding - basic	31,740,923	31,409,322
Effect of dilutive securities:
Dilutive securities	713,141	580,648
Weighted average number of shares outstanding - diluted	32,454,064	31,989,970
Antidilutive securites excluded under the treasury method from computation of earnings per share	267,444	296,844
Employee Stock Option [Member]
Effect of dilutive securities:
Dilutive securities	310,899	277,376
Restricted Stock Units (RSUs) [Member]
Effect of dilutive securities:
Dilutive securities	79,392	89,151
Performance Shares [Member]
Effect of dilutive securities:
Dilutive securities	322,850	214,121