ProAssurance (PRA) 10-Q 6 Aug 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 31, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	PROASSURANCE CORP
Entity Central Index Key	1,127,703
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Amendment Flag	false
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		53,667,668
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Investments
Fixed maturities, available for sale, at fair value; amortized cost, $2,903,152 and $3,055,477, respectively	$ 2,967,353	$ 3,145,027
Equity securities, trading, at fair value; cost, $290,811 and $283,107 respectively	307,326	314,482
Short-term investments	144,351	131,259
Business owned life insurance	56,090	56,381
Investment in unconsolidated subsidiaries	291,661	276,501
Other investments, $31,600 and $28,958 at fair value, respectively, otherwise at cost or amortized cost	91,110	86,057
Total Investments	3,857,891	4,009,707
Cash and cash equivalents	151,366	197,040
Premiums receivable	219,993	202,528
Receivable from reinsurers on paid losses and loss adjustment expenses	9,024	6,494
Receivable from reinsurers on unpaid losses and loss adjustment expenses	237,801	237,966
Prepaid reinsurance premiums	35,673	32,115
Deferred policy acquisition costs	44,398	38,790
Real estate, net	39,374	39,799
Intangible assets	96,598	100,733
Goodwill	210,725	210,725
Other assets	98,648	93,263
Total Assets	5,001,491	5,169,160
Policy liabilities and accruals
Reserve for losses and loss adjustment expenses	2,026,697	2,058,266
Unearned premiums	370,459	345,828
Reinsurance premiums payable	24,143	17,451
Total Policy Liabilities	2,421,299	2,421,545
Deferred tax liability	11,142	18,818
Other liabilities	161,866	320,853
Long-term debt	350,000	250,000
Total Liabilities	2,944,307	3,011,216
Shareholders’ Equity
Common shares, par value $0.01 per share, 100,000,000 shares authorized, 62,496,623 and 62,297,214 shares issued, respectively	625	623
Additional paid-in capital	362,230	359,577
Accumulated other comprehensive income (loss), net of deferred tax expense (benefit) of $21,784 and $31,342, respectively	41,049	58,204
Retained earnings	2,028,745	1,991,704
Treasury shares, at cost, 8,481,567 shares and 5,763,388 shares, respectively	(375,465)	(252,164)
Total Shareholders’ Equity	2,057,184	2,157,944
Total Liabilities and Shareholders’ Equity	$ 5,001,491	$ 5,169,160

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Fixed maturities, available for sale, at fair value; amortized cost	$ 2,903,152	$ 3,055,477
Equity securities, trading, cost	290,811	283,107
Other investments, portion carried at fair value	$ 31,600	$ 28,958
Common shares, par value (USD per share)	$ 0.01	$ 0.01
Common shares, shares authorized	100,000,000	100,000,000
Common shares, shares issued	62,496,623	62,297,214
Deferred tax expense (benefit) on accumulated other comprehensive income (loss)	$ 21,784	$ 31,342
Treasury shares, number of shares	8,481,567	5,763,388

Condensed Consolidated Statemen

Condensed Consolidated Statements of Changes in Capital - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Increase (Decrease) in Stockholders' Equity:
Beginning Balance			$ 2,157,944	$ 2,394,414
Common shares reacquired			(123,301)	(122,281)
Common shares issued for compensation			2,082	2,685
Share-based compensation	$ 2,300	$ 2,400	4,966	5,641
Net effect of restricted and performance shares issued and stock options exercised			(4,393)	(2,819)
Dividends to shareholders			(33,931)	(35,534)
Other comprehensive income (loss)			(17,155)	21,992
Net income	33,158	49,942	70,972	96,673
Ending Balance	2,057,184	2,360,771	2,057,184	2,360,771
Common Stock
Increase (Decrease) in Stockholders' Equity:
Beginning Balance			623	621
Net effect of restricted and performance shares issued and stock options exercised			2	2
Ending Balance	625	623	625	623
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity:
Beginning Balance			359,577	349,894
Common shares issued for compensation			2,082	2,685
Share-based compensation			4,966	5,641
Net effect of restricted and performance shares issued and stock options exercised			(4,395)	(2,821)
Ending Balance	362,230	355,399	362,230	355,399
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity:
Beginning Balance			58,204	59,661
Other comprehensive income (loss)			(17,155)	21,992
Ending Balance	41,049	81,653	41,049	81,653
Retained Earnings
Increase (Decrease) in Stockholders' Equity:
Beginning Balance			1,991,704	2,015,603
Dividends to shareholders			(33,931)	(35,534)
Net income			70,972	96,673
Ending Balance	2,028,745	2,076,742	2,028,745	2,076,742
Treasury Stock
Increase (Decrease) in Stockholders' Equity:
Beginning Balance			(252,164)	(31,365)
Common shares reacquired			(123,301)	(122,281)
Ending Balance	$ (375,465)	$ (153,646)	$ (375,465)	$ (153,646)

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Income and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues
Net premiums earned		$ 175,293	$ 176,303	$ 347,192	$ 348,032
Net investment income		27,955	30,225	55,258	59,957
Equity in earnings (loss) of unconsolidated subsidiaries		2,420	719	4,041	2,470
Net realized investment gains (losses):
Other-than-temporary impairment (OTTI) losses		(1,209)	0	(4,480)	(50)
Portion of OTTI losses recognized in (reclassified from) other comprehensive income before taxes		348	0	1,789	0
Net impairment losses recognized in earnings		(861)	0	(2,691)	(50)
Other net realized investment gains (losses)		(2,967)	13,046	3,702	15,840
Total net realized investment gains (losses)		(3,828)	13,046	1,011	15,790
Other income		1,576	2,154	3,745	4,249
Total revenues		203,416	222,447	411,247	430,498
Expenses
Losses and loss adjustment expenses		112,747	104,052	230,915	200,104
Reinsurance recoveries		(8,808)	(5,139)	(21,837)	(11,683)
Net losses and loss adjustment expenses		103,939	98,913	209,078	188,421
Underwriting, policy acquisition and operating expenses	[1]	53,525	52,157	104,881	104,672
Segregated portfolio cells dividend expense		1,230	1,789	3,414	2,838
Interest expense		3,710	3,521	7,341	7,091
Total expenses		162,404	156,380	324,714	303,022
Income before income taxes		41,012	66,067	86,533	127,476
Provision for income taxes
Current expense (benefit)		13,776	14,389	14,128	22,294
Deferred expense (benefit)		(5,922)	1,736	1,433	8,509
Total income tax expense (benefit)		7,854	16,125	15,561	30,803
Net income		33,158	49,942	70,972	96,673
Other comprehensive income (loss), after tax, net of reclassification adjustments		(24,828)	11,247	(17,155)	21,992
Comprehensive income		$ 8,330	$ 61,189	$ 53,817	$ 118,665
Earnings per share:
Basic (USD per share)		$ 0.60	$ 0.84	$ 1.27	$ 1.60
Diluted (USD per share)		$ 0.60	$ 0.84	$ 1.26	$ 1.59
Weighted average number of common shares outstanding:
Basic (in shares)		55,445	59,524	56,016	60,383
Diluted (in shares)		55,645	59,742	56,226	60,615
Cash dividends declared per common share (USD per share)		$ 0.31	$ 0.3	$ 0.62	$ 0.6
[1]	Beginning with the first quarter of 2015, the operating subsidiaries within the Specialty P&C and Workers' Compensation segments were charged a management fee by the Corporate segment for various management services provided to the subsidiary. Under the new arrangement, the expenses associated with such services are reported as expenses of the Corporate segment, and the management fees charged are reported as an offset to Corporate operating expenses. Prior to 2015, a substantial portion of expenses associated with corporate services were directly allocated to the insurance subsidiaries included in the Specialty P&C segment.

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating Activities
Net income	$ 70,972	$ 96,673
Depreciation and amortization, net of accretion	23,668	23,974
Net realized investment gains	(1,011)	(15,790)
Share-based compensation	4,966	5,641
Deferred income taxes	1,433	8,509
Policy acquisition costs, net amortization (net deferral)	(5,608)	(4,535)
Equity in earnings of unconsolidated subsidiaries, excluding distributions received and tax credit partnership amortization	(7,973)	(5,941)
Other	(674)	(439)
Other changes in assets and liabilities, excluding effect of business combinations:
Premiums receivable	(17,465)	(27,786)
Reinsurance related assets and liabilities	769	(17,128)
Other assets	(5,909)	(6,017)
Reserve for losses and loss adjustment expenses	(31,569)	(50,284)
Unearned premiums	24,631	27,441
Other liabilities	(2,478)	(5,184)
Net cash provided (used) by operating activities	53,752	29,134
Purchases of:
Fixed maturities, available for sale	(375,552)	(365,421)
Equity securities, trading	(153,610)	(56,006)
Other investments	(15,786)	(19,535)
Funding of tax credit limited partnerships	(659)	(5,348)
Investment in unconsolidated subsidiaries	(26,275)	(16,603)
Proceeds from sales or maturities of:
Fixed maturities, available for sale	520,169	342,347
Equity securities, trading	157,005	85,477
Other investments	11,918	10,288
Distributions from unconsolidated subsidiaries	13,619	0
Net sales or maturities (purchases) of short-term investments	(13,130)	99,244
Cash received in acquisitions	0	35,013
Unsettled security transactions, net change	1,229	19,866
(Increase) decrease in restricted cash	0	78,000
Other	(5,266)	6,065
Net cash provided (used) by investing activities	113,662	213,387
Financing Activities
Borrowing under revolving credit agreement	100,000	0
Repurchase of common stock	(123,301)	(119,593)
Dividends to shareholders	(184,411)	(36,223)
Other	(5,376)	(5,429)
Net cash provided (used) by financing activities	(213,088)	(161,245)
Increase (decrease) in cash and cash equivalents	(45,674)	81,276
Cash and cash equivalents at beginning of period	197,040	129,383
Cash and cash equivalents at end of period	151,366	210,659
Significant non-cash transactions
Deposit transferred as consideration for acquisition	0	205,244
Dividends declared and not yet paid	$ 16,728	$ 17,607

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited Condensed Consolidated Financial Statements include the accounts of ProAssurance Corporation and its consolidated subsidiaries (ProAssurance, PRA or the Company). The financial statements have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. 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 considered necessary for a fair presentation, consisting of normal recurring adjustments, have been included. ProAssurance’s results for the six months ended June 30, 2015 are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 . The accompanying Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and Notes contained in ProAssurance’s December 31, 2014 report on Form 10-K. In connection with its preparation of the Condensed Consolidated Financial Statements, ProAssurance evaluated events that occurred subsequent to June 30, 2015 for recognition or disclosure in its financial statements and notes to financial statements. ProAssurance operates in four reportable segments as follows: Specialty P&C , Workers' Compensation, Lloyd's Syndicate, and Corporate. For more information on the nature of products and services provided and for financial information by segment, refer to Note 12 of the Notes to Condensed Consolidated Financial Statements. Other Liabilities Other liabilities consisted of the following: (In millions) June 30, 2015 December 31, 2014 SPC dividends payable $ 18.6 $ 15.8 Unpaid dividends 16.7 167.7 All other 126.6 137.4 Total other liabilities $ 161.9 $ 320.9 SPC dividends payable are the cumulative undistributed earnings contractually payable to the external preferred shareholders of SPC s operated by ProAssurance's Cayman Islands subsidiary, Eastern Re. Unpaid dividends represents common stock dividends declared by ProAssurance's Board of Directors that have not yet been paid. Unpaid dividends at December 31, 2014 reflect a special dividend declared in late 2014 that was paid in January 2015. Accounting Changes Adopted Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity Effective for fiscal years beginning after December 15, 2014, the FASB issued guidance regarding the requirements for reporting discontinued operations. Under the new guidance, reporting entities are required to report disposals of business components only if the disposal represents a strategic shift in the entity’s operations that will have a major effect on the entity’s operations and financial results. The new guidance expands disclosure requirements for reported discontinued operations and requires disclosure of pre-tax profit or loss attributable to significant disposals that are not reported as discontinued operations. ProAssurance adopted the guidance as of January 1, 2015. Adoption of the guidance had no effect on ProAssurance’s results of operations or financial position. Disclosures for Investments in Certain Entities that Calculate Net Asset Value per Share (or Its Equivalent) Effective for fiscal years beginning after December 15, 2015, the FASB issued guidance which removed the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The guidance also revised other disclosure requirements for investments measured or eligible to be measured at fair value using the net asset value per share practical expedient. ProAssurance adopted the guidance as of June 30, 2015 as early adoption is permitted. Adoption of the guidance had no effect on ProAssurance's results of operations or financial position as it affected disclosures only. Accounting Changes Not Yet Adopted Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period Effective for fiscal years beginning after December 15, 2015, the FASB issued guidance for share-based payments in which the terms of the award provide that a performance target can be achieved after completion of the requisite service period. The new guidance provides that compensation cost for such awards should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. ProAssurance plans to adopt the guidance beginning January 1, 2016. Adoption of the guidance is expected to have no effect on ProAssurance’s results of operations or financial position as ProAssurance has no awards with performance targets extending beyond the requisite service period. Revenue from Contracts with Customers Effective for fiscal years beginning after December 15, 2016, the FASB issued guidance related to revenue from contracts with customers. The core principle of the new guidance is that revenue should be recognized to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ProAssurance plans to adopt the guidance beginning January 1, 2017. As the majority of ProAssurance's revenues come from insurance contracts which fall under the scope of other FASB standards, adoption of the guidance is expected to have no material effect on ProAssurance’s results of operations or financial position. Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern Effective for fiscal years ending after December 15, 2016 and interim periods beginning after December 15, 2016, the FASB issued guidance that establishes principles and definitions related to management's evaluation of whether there is substantial doubt about the organization's ability to continue as a going concern. For each interim and annual reporting period, the new guidance requires management to evaluate the organization's ability to meet its obligations as they are due within one year of the date the financial statements are issued and requires disclosure when there is substantial doubt regarding the organization's ability to continue as a going concern. ProAssurance plans to adopt the guidance on its effective date. Adoption is expected to have no effect on ProAssurance’s results of operations or financial position. Simplifying the Presentation of Debt Issuance Costs Effective for fiscal years beginning after December 15, 2015, the FASB issued guidance related to the presentation of debt issuance costs. The new guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. ProAssurance plans to adopt the guidance beginning January 1, 2016. Adoption of the guidance is not expected to have a material effect on ProAssurance’s results of operations or financial position. Amendments to the Consolidation Analysis Effective for fiscal years beginning after December 15, 2015, the FASB issued additional guidance regarding the consolidation of legal entities such as limited partnerships, limited liability corporations, and securitization structures (collateralized debt obligations, collateralized loan obligations, and mortgage-backed security transactions). The new standard modifies the evaluation of whether or not entities are VIE s and the consolidation analysis of entities involved with VIE s, particularly those having fee arrangements and related party relationships. ProAssurance is in the process of evaluating the effect, if any, of the new guidance on its results of operations and financial position and plans to adopt the guidance beginning January 1, 2016. The effect is not expected to be material. Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement Effective for fiscal years beginning after December 15, 2015, the FASB issued additional guidance regarding accounting for cloud computing arrangements. Under the new guidance, customers participating in cloud computing arrangements that include a software license should account for the software license element of the arrangement consistent with the acquisition of other software licenses. Customers should account for cloud computing arrangements that do not include a software license as a service contract, following existing guidance for service contracts. ProAssurance is in the process of evaluating the effect that the use of the new method would have on its results of operations and financial position and plans to adopt the guidance beginning January 1, 2016. The effect is not expected to be material. Disclosures about Short-Duration Contracts Effective for fiscal years beginning after December 15, 2015, the FASB issued guidance that requires insurance entities to provide detailed discloses relative to the reserve for losses and loss adjustment expenses in annual reporting periods and a roll-forward of the reserve for losses and loss adjustment expenses in interim reporting periods. The guidance also requires disclosures regarding significant changes in the methodologies and assumptions used to calculate the reserve for losses and loss adjustment expenses, including reasons for and the effects of such changes. ProAssurance plans to adopt the guidance beginning January 1, 2016. Adoption of the guidance is not expected to have a material effect on ProAssurance's results of operations or financial position as it affects disclosures only.

Fair Value Measurement

Fair Value Measurement	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. A three level hierarchy has been established for valuing assets and liabilities based on how transparent (observable) the inputs are that are used to determine fair value, with the inputs considered most observable categorized as Level 1 and those that are the least observable categorized as Level 3. Hierarchy levels are defined as follows: Level 1: quoted (unadjusted) market prices in active markets for identical assets and liabilities. For ProAssurance, Level 1 inputs are generally quotes for debt or equity securities actively traded in exchange or over-the-counter markets. Level 2: market data obtained from sources independent of the reporting entity (observable inputs). For ProAssurance, Level 2 inputs generally include quoted prices in markets that are not active, quoted prices for similar assets or liabilities, and results from pricing models that use observable inputs such as interest rates and yield curves that are generally available at commonly quoted intervals. Level 3: the reporting entity's own assumptions about market participant assumptions based on the best information available in the circumstances (non-observable inputs). For ProAssurance, Level 3 inputs are used in situations where little or no Level 1 or 2 inputs are available or are inappropriate given the particular circumstances. Level 3 inputs include results from pricing models for which some or all of the inputs are not observable, discounted cash flow methodologies, single non-binding broker quotes and adjustments to externally quoted prices that are based on management judgment or estimation. Fair values of assets measured at fair value on a recurring basis as of June 30, 2015 and December 31, 2014 are shown in the following tables. The tables also indicate the fair value hierarchy of the valuation techniques utilized to determine those fair values. For some assets, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. When this is the case, the asset is categorized based on the level of the most significant input to the fair value measurement. Assessments of the significance of a particular input to the fair value measurement require judgment and consideration of factors specific to the assets being valued. June 30, 2015 Fair Value Measurements Using Total (In thousands) Level 1 Level 2 Level 3 Fair Value Assets: Fixed maturities, available for sale U.S. Treasury obligations $ — $ 99,506 $ — $ 99,506 U.S. Government-sponsored enterprise obligations — 29,735 — 29,735 State and municipal bonds — 1,003,611 — 1,003,611 Corporate debt, multiple observable inputs 2,262 1,396,416 — 1,398,678 Corporate debt, limited observable inputs: Other corporate debt, NRSRO ratings available — — 7,927 7,927 Other corporate debt, NRSRO ratings not available — — 541 541 Residential mortgage-backed securities — 267,273 — 267,273 Agency commercial mortgage-backed securities — 11,348 — 11,348 Other commercial mortgage-backed securities — 45,617 — 45,617 Other asset-backed securities — 98,340 4,777 103,117 Equity securities Financial 71,102 — — 71,102 Utilities/Energy 38,219 — — 38,219 Consumer oriented 48,270 — 76 48,346 Industrial 40,846 — — 40,846 Bond funds 79,419 — — 79,419 All other 16,391 13,003 — 29,394 Short-term investments 141,496 2,855 — 144,351 Other investments 3,346 27,294 960 31,600 Total assets categorized within the fair value hierarchy $ 441,351 $ 2,994,998 $ 14,281 $ 3,450,630 LP/LLC interests carried at NAV which approximates fair value. These interests, reported as a part of Investment in unconsolidated subsidiaries, are not categorized within the fair value hierarchy. 149,083 Total assets at fair value $ 3,599,713 December 31, 2014 Fair Value Measurements Using Total (In thousands) Level 1 Level 2 Level 3 Fair Value Assets: Fixed maturities, available for sale U.S. Treasury obligations $ — $ 166,512 $ — $ 166,512 U.S. Government-sponsored enterprise obligations — 39,563 — 39,563 State and municipal bonds — 1,057,590 5,025 1,062,615 Corporate debt, multiple observable inputs — 1,404,020 — 1,404,020 Corporate debt, limited observable inputs: Other corporate debt, NRSRO ratings available — — 10,474 10,474 Other corporate debt, NRSRO ratings not available — — 2,607 2,607 Residential mortgage-backed securities — 276,056 — 276,056 Agency commercial mortgage-backed securities — 15,493 — 15,493 Other commercial mortgage-backed securities — 51,063 — 51,063 Other asset-backed securities — 111,855 4,769 116,624 Equity securities Financial 79,341 — — 79,341 Utilities/Energy 25,629 — — 25,629 Consumer oriented 65,670 — — 65,670 Industrial 55,460 — — 55,460 Bond funds 55,196 — — 55,196 All other 33,186 — — 33,186 Short-term investments 131,199 60 — 131,259 Other investments 6,050 22,908 — 28,958 Total assets categorized within the fair value hierarchy $ 451,731 $ 3,145,120 $ 22,875 $ 3,619,726 LP/LLC interests carried at NAV which approximates fair value. These interests, reported as a part of Investment in unconsolidated subsidiaries, are not categorized within the fair value hierarchy. 133,250 Total assets at fair value $ 3,752,976 The fair values for securities included in the Level 2 category, with the few exceptions described below, were developed by one of several third party, nationally recognized pricing services, including services that price only certain types of securities. Each service uses complex methodologies to determine values for securities and subject the values they develop to quality control reviews. Management selected a primary source for each type of security in the portfolio and reviewed the values provided for reasonableness by comparing data to alternate pricing services and to available market and trade data. Values that appeared inconsistent were further reviewed for appropriateness. If a value did not appear reasonable, the valuation was discussed with the service that provided the value and would have been adjusted, if necessary. No such adjustments were necessary in 2015 or 2014 . Level 2 Valuations Below is a summary description of the valuation methodologies primarily used by the pricing services for securities in the Level 2 category, by security type: U.S. Treasury obligations were valued based on quoted prices for identical assets, or, in markets that are not active, quotes for similar assets, taking into consideration adjustments for variations in contractual cash flows and yields to maturity. U.S. Government-sponsored enterprise obligations were valued using pricing models that consider current and historical market data, normal trading conventions, credit ratings, and the particular structure and characteristics of the security being valued, such as yield to maturity, redemption options, and contractual cash flows. Adjustments to model inputs or model results were included in the valuation process when necessary to reflect recent regulatory, government or corporate actions or significant economic, industry or geographic events affecting the security’s fair value. State and municipal bonds were valued using a series of matrices that considered credit ratings, the structure of the security, the sector in which the security falls, yields, and contractual cash flows. Valuations were further adjusted, when necessary, to reflect the expected effect on fair value of recent significant economic or geographic events or ratings changes. Corporate debt with multiple observable inputs consisted primarily of corporate bonds, but also included a small number of bank loans. The methodology used to value Level 2 corporate bonds was the same as the methodology previously described for U.S. Government-sponsored enterprise obligations. Bank loans were valued based on an average of broker quotes for the loans in question, if available. If quotes were not available, the loans were valued based on quoted prices for comparable loans or, if the loan was newly issued, by comparison to similar seasoned issues. Broker quotes were compared to actual trade prices on a regular basis to permit assessment of the reliability of the quotes; unreliable quotes were not considered in quoted averages. Residential and commercial mortgage backed securities . Agency pass-through securities were valued using a pricing matrix which considers the issuer type, coupon rate and longest cash flows outstanding. The matrix used was based on the most recently available market information. Agency and non-agency collateralized mortgage obligations were both valued using models that consider the structure of the security, current and historical information regarding prepayment speeds, ratings and ratings updates, and current and historical interest rate and interest rate spread data. Other asset-backed securities were valued using models that consider the structure of the security, monthly payment information, current and historical information regarding prepayment speeds, ratings and ratings updates, and current and historical interest rate and interest rate spread data. Spreads and prepayment speeds considered collateral type. Equity securities were securities not traded on an exchange on the valuation date. The securities were valued using the most recently available quotes for the securities. Short-term investments are securities maturing within one year, carried at cost which approximated the fair value of the security due to the short term to maturity. Other investments consisted of convertible bonds valued using a pricing model that incorporated selected dealer quotes as well as current market data regarding equity prices and risk free rates. If dealer quotes were unavailable for the security being valued, quotes for securities with similar terms and credit status were used in the pricing model. Dealer quotes selected for use were those considered most accurate based on parameters such as underwriter status and historical reliability. Level 3 Valuations Below is a summary description of the valuation processes and methodologies used as well as quantitative information regarding securities in the Level 3 category. Level 3 Valuation Processes • Level 3 securities are priced by the Chief Investment Officer. • Level 3 valuations are computed quarterly. Prices are evaluated quarterly against prior period prices and the expected change in price. • The securities noted in the disclosure are primarily NRSRO rated debt instruments for which comparable market inputs are commonly available for evaluating the securities in question. Valuation of these debt instruments is not overly sensitive to changes in the unobservable inputs used. Level 3 Valuation Methodologies State and municipal bonds consisted of auction rate municipal bonds valued internally using either published quotes for similar securities or values produced by discounted cash flow models using yields currently available on fixed rate securities with a similar term and collateral, adjusted to consider the effect of a floating rate and a premium for illiquidity. Corporate debt with limited observable inputs consisted of corporate bonds valued using dealer quotes for similar securities or discounted cash flow models using yields currently available for similar securities. Similar securities are defined as securities of comparable credit quality that have like terms and payment features. Assessments of credit quality were based on NRSRO ratings, if available, or were subjectively determined by management if not available. At June 30, 2015 , 94% of the securities were rated; the average rating was A- . Other asset-backed securities consisted of securitizations of receivables valued using dealer quotes for similar securities or discounted cash flow models using yields currently available for similar securities. Equity securities and Other investments consisted of common stock and convertible securities for which limited observable inputs were available at June 30, 2015 . The securities were valued internally based on expected cash flows, including the expected final recovery, discounted at a yield that considered the lack of liquidity and the financial status of the issuer. Quantitative Information Regarding Level 3 Valuations Fair Value at (In millions) June 30, 2015 December 31, 2014 Valuation Technique Unobservable Input Range Assets: State and municipal bonds $— $5.0 Market Comparable Comparability Adjustment 0% - 10% (5%) Discounted Cash Flows Comparability Adjustment 0% - 10% (5%) Corporate debt with limited observable inputs $8.5 $13.1 Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Other asset-backed securities $4.8 $4.8 Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Equity securities and Other investments $1.1 $— Discounted Cash Flows Comparability Adjustment 0% - 10% (5%) The significant unobservable inputs used in the fair value measurement of the above listed securities were the valuations of comparable securities with similar issuers, credit quality and maturity. Changes in the availability of comparable securities could result in changes in the fair value measurements. Fair Value Measurements - Level 3 Assets The following tables (the Level 3 Tables) present summary information regarding changes in the fair value of assets measured at fair value using Level 3 inputs. June 30, 2015 Level 3 Fair Value Measurements – Assets (In thousands) U.S. Government-sponsored Enterprise Obligations State and Municipal Bonds Corporate Debt Asset-backed Securities Equity Securities and Other Investments Total Balance March 30, 2015 $ — $ 5,025 $ 9,977 $ 4,788 $ — $ 19,790 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income — — — — — — Net realized investment gains (losses) — — — — — — Included in other comprehensive income — (459 ) 21 (11 ) (80 ) (529 ) Purchases — — — — 1,116 1,116 Sales — — (536 ) — — (536 ) Transfers in — — — — — — Transfers out — (4,566 ) (994 ) — — (5,560 ) Balance June 30, 2015 $ — $ — $ 8,468 $ 4,777 $ 1,036 $ 14,281 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ — $ — $ — June 30, 2015 Level 3 Fair Value Measurements – Assets (In thousands) U.S. Government-sponsored Enterprise Obligations State and Municipal Bonds Corporate Debt Asset-backed Securities Equity Securities and Other Investments Total Balance December 31, 2014 $ — $ 5,025 $ 13,081 $ 4,769 $ — $ 22,875 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income — — 17 — — 17 Net realized investment gains (losses) — — 2 — — 2 Included in other comprehensive income — (459 ) (262 ) 8 (80 ) (793 ) Purchases — — 1,515 — 1,116 2,631 Sales — — (836 ) — — (836 ) Transfers in — — — — — — Transfers out — (4,566 ) (5,049 ) — — (9,615 ) Balance June 30, 2015 $ — $ — $ 8,468 $ 4,777 $ 1,036 $ 14,281 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ — $ — $ — June 30, 2014 Level 3 Fair Value Measurements – Assets (In thousands) U.S. Government-sponsored Enterprise Obligations State and Municipal Bonds Corporate Debt Asset-backed Securities Equity Securities and Other Investments Total Balance March 30, 2014 $ 999 $ 7,490 $ 12,381 $ 7,226 $ — $ 28,096 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income — (4 ) 16 — — 12 Net realized investment gains (losses) — — — — — — Included in other comprehensive income 2 (26 ) (2 ) 25 — (1 ) Purchases — — 2,499 1,175 — 3,674 Sales — — (350 ) (61 ) — (411 ) Transfers in — 1,549 — — — 1,549 Transfers out (1,001 ) (1,861 ) — (2,405 ) — (5,267 ) Balance June 30, 2014 $ — $ 7,148 $ 14,544 $ 5,960 $ — $ 27,652 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ — $ — $ — June 30, 2014 Level 3 Fair Value Measurements – Assets (In thousands) U.S. Government-sponsored Enterprise Obligations State and Municipal Bonds Corporate Debt Asset-backed Securities Equity Securities and Other Investments Total Balance December 31, 2013 $ — $ 7,338 $ 14,176 $ 6,814 $ — $ 28,328 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income — (6 ) 32 — — 26 Net realized investment gains (losses) — (95 ) 3 — — (92 ) Included in other comprehensive income 1 42 667 69 — 779 Purchases 1,000 1,861 2,499 3,340 — 8,700 Sales — (257 ) (808 ) (61 ) — (1,126 ) Transfers in — 2,119 — 305 — 2,424 Transfers out (1,001 ) (3,854 ) (2,025 ) (4,507 ) — (11,387 ) Balance June 30, 2014 $ — $ 7,148 $ 14,544 $ 5,960 $ — $ 27,652 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ — $ — $ — Transfers There were no transfers between the Level 1 and Level 2 categories during the three and six months ended June 30, 2015 or 2014 . Transfers shown in the preceding Level 3 tables were as of the end of the period and were to or from Level 2. All transfers during the three and six months ended June 30, 2015 and June 30, 2014 related to securities held for which the level of market activity for identical or nearly identical securities varies from period to period. The securities were valued using multiple observable inputs when those inputs were available; otherwise the securities were valued using limited observable inputs. Fair Values Not Categorized Investments in unconsolidated subsidiaries at both June 30, 2015 and December 31, 2014 included interests in investment fund LP s/ LLC s that measure fund assets at fair value on a recurring basis and that provide a NAV for the interest. The carrying value of these interests is based on the NAV provided, and was considered to approximate the fair value of the interests. In accordance with GAAP , the fair value of these investments was not classified within the fair value hierarchy. Additional information regarding these investments is as follows: Unfunded Fair Value (In thousands) June 30, June 30, December 31, Investments in LPs/LLCs: Private debt funds (1) $25,946 $ 38,812 $ 37,296 Long equity fund (2) None 7,058 6,747 Long/short equity funds (3) None 25,356 25,301 Non-public equity funds (4) $53,356 65,374 51,811 Multi-strategy fund of funds (5) None 8,534 8,271 Structured credit fund (6) None 3,949 3,824 $ 149,083 $ 133,250 (1) Comprised of interests in two unrelated LP funds that are structured to provide interest distributions primarily through diversified portfolios of private debt instruments. One LP allows redemption by special consent; the other does not permit redemption. Income and capital are to be periodically distributed at the discretion of the LP s over an anticipated time frame that spans from 3 to 8 years. (2) The fund is an LP that holds long equities of public international companies. Redemptions are allowed at the end of any calendar month with a prior notice requirement of 15 days and are paid within 10 days of the end of the calendar month of the redemption request. (3) Comprised of interests in multiple unrelated LP funds. The funds hold primarily long and short North American equities, and target absolute returns using strategies designed to take advantage of event-driven market opportunities. The funds generally permit quarterly or semi-annual capital redemptions subject to notice requirements of 30 to 90 days. For some funds, redemptions above specified thresholds (lowest threshold is 90% ) may be only partially payable until after a fund audit is completed and are then payable within 30 days. (4) Comprised of interests in three unrelated LP funds, each structured to provide capital appreciation through diversified investments in private equity, which can include investments in buyout, venture capital, mezzanine debt, distressed debt and other private equity-oriented LP s. One LP allows redemption by special consent; the others do not permit redemption. Income and capital are to be periodically distributed at the discretion of the LP over time frames that are anticipated to span up to 9 years. (5) This fund is an LLC structured to build and manage low volatility, multi-manager portfolios that have little or no correlation to the broader fixed income and equity security markets. Redemptions are not permitted but the LLC Board is permitted discretion to periodically extend offers to repurchase units of the LLC . (6) This fund is an LP seeking to obtain superior risk-adjusted absolute returns by acquiring and actively managing a diversified portfolio of debt securities, including bonds, loans and other asset-backed instruments. Redemptions are allowed at any quarter-end with a prior notice requirement of 90 days . ProAssurance may not sell, transfer or assign its interest in any of the above LP s/ LLC s without special consent from the LP / LLC . Financial Instruments - Methodologies Other Than Fair Value The following table provides the estimated fair value of our financial instruments that, in accordance with GAAP for the type of investment, are measured using a methodology other than fair value. All fair values provided fall within the Level 3 fair value category. June 30, 2015 December 31, 2014 (In thousands) Carrying Fair Carrying Fair Financial assets: BOLI $ 56,090 $ 56,090 $ 56,381 $ 56,381 Other investments $ 59,510 $ 56,672 $ 57,099 $ 57,994 Other assets $ 23,079 $ 23,052 $ 22,440 $ 22,399 Financial liabilities: Senior notes due 2023 $ 250,000 $ 267,853 $ 250,000 $ 276,503 Revolving credit agreement $ 100,000 $ 100,000 $ — $ — Other liabilities $ 15,259 $ 15,253 $ 14,656 $ 14,645 The fair value of the BOLI was equal to the cash surrender value associated with the policies on the valuation date. Other investments listed in the table above include interests in certain investment fund LP s/ LLC s accounted for using the cost method, investments in FHLB common stock carried at cost, and an annuity investment carried at amortized cost. The estimated fair value of the LP / LLC interests was based on the equity value of the interest provided by the LP / LLC managers for the most recent quarter, which approximates the fair value of the interest. The estimated fair value of the FHLB common stock was based on the amount ProAssurance would receive if its membership were canceled, as the membership cannot be sold. The fair value of the annuity represents the present value of the expected future cash flows discounted using a rate available in active markets for similarly structured instruments. Other assets and Other liabilities primarily consisted of related investment assets and liabilities associated with funded deferred compensation agreements. Fair values of the funded deferred compensation assets and liabilities were based on the NAV s provided by the underlying funds. Other assets also included a secured note receivable and an unsecured receivable under a revolving credit agreement. Fair value of these receivables was based on the present value of expected cash flows from the receivables, discounted at market rates on the valuation date for receivables with similar credit standings and similar payment structures. Other liabilities also included certain contractual liabilities related to prior business combinations. The fair values of the business combination liabilities were based on the present value of the expected future cash outflows, discounted at ProAssurance’s assumed incremental borrowing rate on the valuation date for unsecured liabilities with similar repayment structures. The fair value of the long-term debt was estimated based on the present value of expected future cash outflows, discounted at rates available on the valuation date for similar debt issued by entities with a similar credit standing to ProAssurance.

Investments

Investments	6 Months Ended
	Jun. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Investments	Investments Available-for-sale securities at June 30, 2015 and December 31, 2014 included the following: June 30, 2015 (In thousands) Amortized Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Fixed maturities U.S. Treasury obligations $ 97,491 $ 2,223 $ 208 $ 99,506 U.S. Government-sponsored enterprise obligations 28,452 1,328 45 29,735 State and municipal bonds 969,667 36,244 2,300 1,003,611 Corporate debt 1,387,556 36,992 17,402 1,407,146 Residential mortgage-backed securities 261,015 7,738 1,480 267,273 Agency commercial mortgage-backed securities 11,135 238 25 11,348 Other commercial mortgage-backed securities 45,032 698 113 45,617 Other asset-backed securities 102,804 368 55 103,117 $ 2,903,152 $ 85,829 $ 21,628 $ 2,967,353 December 31, 2014 (In thousands) Amortized Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Fixed maturities U.S. Treasury obligations $ 163,714 $ 3,785 $ 987 $ 166,512 U.S. Government-sponsored enterprise obligations 38,022 1,641 100 39,563 State and municipal bonds 1,015,555 47,395 335 1,062,615 Corporate debt 1,389,970 44,234 17,103 1,417,101 Residential mortgage-backed securities 266,306 10,198 448 276,056 Agency commercial mortgage-backed securities 15,344 208 59 15,493 Other commercial mortgage-backed securities 50,025 1,137 99 51,063 Other asset-backed securities 116,541 288 205 116,624 $ 3,055,477 $ 108,886 $ 19,336 $ 3,145,027 The recorded cost basis and estimated fair value of available-for-sale fixed maturities at June 30, 2015 , by contractual maturity, 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. (In thousands) Amortized Due in one Due after Due after Due after Total Fair Fixed maturities, available for sale U.S. Treasury obligations $ 97,491 $ 14,924 $ 69,645 $ 11,744 $ 3,193 $ 99,506 U.S. Government-sponsored enterprise obligations 28,452 2,649 19,404 7,345 337 29,735 State and municipal bonds 969,667 50,386 341,963 443,042 168,220 1,003,611 Corporate debt 1,387,556 106,506 731,107 540,308 29,225 1,407,146 Residential mortgage-backed securities 261,015 267,273 Agency commercial mortgage-backed securities 11,135 11,348 Other commercial mortgage-backed securities 45,032 45,617 Other asset-backed securities 102,804 103,117 $ 2,903,152 $ 2,967,353 Excluding obligations of the U.S. Government or U.S. Government-sponsored enterprises, no investment in any entity or its affiliates exceeded 10% of Shareholders’ equity at June 30, 2015 . Cash and securities with a carrying value of $49.6 million at June 30, 2015 were on deposit with various state insurance departments to meet regulatory requirements. ProAssurance also held securities with a carrying value of $126.4 million at June 30, 2015 that are pledged as collateral security for advances under the Revolving Credit Agreement (see Note 8 of the Notes to Condensed Consolidated Financial Statements for additional detail on the Revolving Credit Agreement ). As a member of Lloyd's and a capital provider to Syndicate 1729, ProAssurance is required to maintain capital at Lloyd's , referred to as FAL . ProAssurance investments at June 30, 2015 included fixed maturities with a fair value of $89.3 million and short term investments with a fair value of approximately $0.2 million on deposit with Lloyd's in order to satisfy these FAL requirements. BOLI ProAssurance holds BOLI policies that are carried at the current cash surrender value of the policies (original cost $33 million ). All insured individuals were management employees at the time the policies were acquired. The primary purpose of the program is to offset future employee benefit expenses through earnings on the cash value of the policies. ProAssurance is the owner and principal beneficiary of these policies. Other Investments Other investments at June 30, 2015 and December 31, 2014 were comprised as follows: (In thousands) June 30, December 31, Investments in LPs/LLCs, at cost $ 55,978 $ 53,258 Convertible securities, at fair value 31,600 28,958 Other, principally FHLB capital stock, at cost 3,532 3,841 $ 91,110 $ 86,057 Investments in convertible securities are carried at fair value as permitted by the accounting guidance for hybrid financial instruments, with changes in fair value recognized in income as a component of Net realized investment gains or losses during the period of change. Interest on convertible securities is recorded on an accrual basis based on contractual interest rates and is included in Net investment income. FHLB capital stock is not marketable, but may be liquidated by terminating membership in the FHLB . The liquidation process can take up to five years . Unconsolidated Subsidiaries ProAssurance holds investments in unconsolidated subsidiaries, accounted for under the equity method. The investments include the following: June 30, 2015 Carrying Value (In thousands) Percentage June 30, December 31, Investment in LPs/LLCs: Qualified affordable housing tax credit partnerships See below $ 126,440 $ 133,143 Other tax credit partnerships See below 3,717 — All other LPs/LLCs < 25% 161,504 143,358 $ 291,661 $ 276,501 Qualified affordable housing tax credit partnership interests held by ProAssurance generate investment returns by providing tax benefits to fund investors in the form of tax credits and project operating losses. The carrying value of these investments reflects our total commitments (both funded and unfunded) to the partnerships. ProAssurance's ownership percentage relative to two of the tax credit partnership interests is almost 100% ; these interests had a carrying value of $55.7 million at June 30, 2015 . ProAssurance's ownership percentage relative to the remaining tax credit partnership interests is less than 20% ; these interests had a carrying value of $70.7 million at June 30, 2015 . ProAssurance does not have the ability to exert control over the partnerships; all are accounted for using the equity method. Other tax credit partnerships are comprised entirely of historic tax credits. The historic tax credits generate investment returns by providing benefits to fund investors in the form of tax credits, tax deductible project operating losses and positive cash flows. ProAssurance's ownership percentage relative to the tax credit partnerships is almost 100%. ProAssurance does not have the ability to exert control over the partnerships; the interests are accounted for using the equity method. As discussed in additional detail in Note 2 of the Notes to Condensed Consolidated Financial Statements, ProAssurance holds interests in certain LP s/ LLC s that are investment funds which measure fund assets at fair value on a recurring basis and the fund managers provide a NAV for the interest. The carrying value of these interests is based on the NAV provided, and is considered to approximate the fair value of the interests; such interests totaled $149.1 million at June 30, 2015 and $133.3 million at December 31, 2014 . ProAssurance also holds interests in other LP s/ LLC s where the carrying value is not considered to approximate the estimated fair value of the interest; such interests totaled $12.4 million at June 30, 2015 and $10.1 million at December 31, 2014 . Investments Held in a Loss Position The following tables provide summarized information with respect to investments held in an unrealized loss position at June 30, 2015 and December 31, 2014 , including the length of time the investment had been held in a continuous unrealized loss position. June 30, 2015 Total Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Fair Unrealized (In thousands) Value Loss Value Loss Value Loss Fixed maturities, available for sale U.S. Treasury obligations $ 31,127 $ 207 $ 25,299 $ 150 $ 5,828 $ 57 U.S. Government-sponsored enterprise obligations 3,447 46 3,447 46 — — State and municipal bonds 130,171 2,300 124,146 2,014 6,025 286 Corporate debt 497,704 17,403 444,860 12,629 52,844 4,774 Residential mortgage-backed securities 82,512 1,480 72,839 1,215 9,673 265 Agency commercial mortgage-backed securities 609 25 187 — 422 25 Other commercial mortgage-backed securities 14,379 114 10,436 92 3,943 22 Other asset-backed securities 27,088 53 18,441 33 8,647 20 $ 787,037 $ 21,628 $ 699,655 $ 16,179 $ 87,382 $ 5,449 Other investments Investments in LPs/LLCs carried at cost $ 29,076 $ 4,552 $ 29,076 $ 4,552 $ — $ — December 31, 2014 Total Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Fair Unrealized (In thousands) Value Loss Value Loss Value Loss Fixed maturities, available for sale U.S. Treasury obligations $ 61,209 $ 987 $ 46,869 $ 617 $ 14,340 $ 370 U.S. Government-sponsored enterprise obligations 6,268 100 2,775 44 3,493 56 State and municipal bonds 39,831 335 18,910 84 20,921 251 Corporate debt 423,107 17,103 326,804 13,236 96,303 3,867 Residential mortgage-backed securities 45,006 448 14,406 31 30,600 417 Agency commercial mortgage-backed securities 4,783 59 70 — 4,713 59 Other commercial mortgage-backed securities 13,860 99 7,005 28 6,855 71 Other asset-backed securities 62,577 205 59,176 109 3,401 96 $ 656,641 $ 19,336 $ 476,015 $ 14,149 $ 180,626 $ 5,187 Other investments Investments in LPs/LLCs carried at cost $ 23,683 $ 3,948 $ 22,265 $ 3,711 $ 1,418 $ 237 As of June 30, 2015 , excluding U.S. Government backed securities, there were 651 debt securities ( 23.5% of all available-for-sale fixed maturity securities held) in an unrealized loss position representing 475 issuers. The greatest and second greatest unrealized loss position among those securities were approximately $1.0 million and $0.8 million , respectively. The securities were evaluated for impairment as of June 30, 2015 . As of December 31, 2014 , excluding U.S. Government backed securities, there were 588 debt securities ( 20.5% of all available-for-sale fixed maturity securities held) in an unrealized loss position representing 434 issuers. The greatest and second greatest unrealized loss position among those securities approximated $1.7 million and $0.7 million , respectively. The securities were evaluated for impairment as of December 31, 2014 . Each quarter, ProAssurance performs a detailed analysis for the purpose of assessing whether any of the securities it holds in an unrealized loss position have suffered an other-than-temporary impairment in value. A detailed discussion of the factors considered in the assessment is included in Note 1 of the Notes to Consolidated Financial Statements included in ProAssurance's December 31, 2014 Form 10-K. Fixed maturity securities held in an unrealized loss position at June 30, 2015 , excluding asset-backed securities, have paid all scheduled contractual payments and are expected to continue doing so. Expected future cash flows of asset-backed securities held in an unrealized loss position were estimated as part of the June 30, 2015 impairment evaluation using the most recently available six-month historical performance data for the collateral (loans) underlying the security or, if historical data was not available, sector based assumptions, and equaled or exceeded the current amortized cost basis of the security. Net Investment Income Net investment income by investment category was as follows: Three Months Ended Six Months Ended (In thousands) 2015 2014 2015 2014 Fixed maturities $ 25,025 $ 28,919 $ 49,984 $ 56,960 Equities 3,456 2,551 6,468 4,818 Short-term and Other investments 396 518 902 1,930 BOLI 474 452 930 898 Investment fees and expenses (1,396 ) (2,215 ) (3,026 ) (4,649 ) Net investment income $ 27,955 $ 30,225 $ 55,258 $ 59,957 Equity in Earnings (Loss) from Unconsolidated Subsidiaries Equity in earnings (loss) from unconsolidated subsidiaries included losses due to amortization resulting from the allocable portion of the projected operating losses of qualified affordable housing project tax credits investments of $2.6 million and $5.2 million for the three- and six-month periods ended June 30, 2015 , respectively, and $2.4 million and $4.0 million for the three- and six-month periods ended June 30, 2014 , respectively. Net Realized Investment Gains (Losses) Realized investment gains and losses are recognized on the specific identification basis. The following table provides detailed information regarding net realized investment gains (losses): Three Months Ended June 30 Six Months Ended June 30 (In thousands) 2015 2014 2015 2014 Total OTTI losses: State and municipal bonds $ — $ — $ — $ (50 ) Corporate debt (1,209 ) — (4,480 ) — Portion recognized in (reclassified from) OCI: Corporate debt 348 — 1,789 — Net impairments recognized in earnings $ (861 ) $ — $ (2,691 ) $ (50 ) Gross realized gains, available-for-sale securities 3,627 2,170 7,640 2,975 Gross realized (losses), available-for-sale securities (810 ) (265 ) (2,065 ) (319 ) Net realized gains (losses), trading securities 9,525 4,819 12,192 18,602 Net realized gains (losses), Other investments 602 68 718 266 Change in unrealized holding gains (losses), trading securities (15,751 ) 5,443 (14,893 ) (7,503 ) Change in unrealized holding gains (losses), convertible securities, carried at fair value (968 ) 811 (698 ) 1,819 Other 808 — 808 — Net realized investment gains (losses) $ (3,828 ) $ 13,046 $ 1,011 $ 15,790 ProAssurance recognized credit-related impairments totaling $0.9 million and $2.7 million for the three- and six-month periods ended June 30, 2015 . The impairments related to high-yield securities from issuers in the energy industry. ProAssurance also recognized non-credit impairments related to these securities of $0.3 million and $1.8 million for the same respective periods, as the fair value of the securities was less than the future cash flows expected to be received from the securities. The following table presents a roll forward of cumulative credit losses recorded in earnings related to impaired debt securities for which a portion of the OTTI was recorded in OCI. Three Months Ended June 30 Six Months Ended June 30 (In thousands) 2015 2014 2015 2014 Balance beginning of period $ 2,062 $ 83 $ 232 $ 83 Additional credit losses recognized during the period, related to securities for which: No OTTI has been previously recognized — — 1,830 — OTTI has been previously recognized 861 — 861 — Reductions due to: Securities sold during the period (realized) (293 ) — (293 ) — Balance June 30 $ 2,630 $ 83 $ 2,630 $ 83 Other information regarding sales and purchases of available-for-sale securities is as follows: Three Months Ended June 30 Six Months Ended June 30 (In millions) 2015 2014 2015 2014 Proceeds from sales (exclusive of maturities and paydowns) $ 95.1 $ 105.7 $ 301.0 $ 122.5 Purchases $ 160.5 $ 235.1 $ 375.6 $ 365.4

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes ProAssurance estimates its annual effective tax rate at the end of each quarterly reporting period and uses this estimated rate to record the provision for income taxes in the interim financial statements. The provision for income taxes is different from that which would be obtained by applying the statutory Federal income tax rate to income before taxes primarily because a portion of ProAssurance’s investment income is tax-exempt, because ProAssurance utilizes tax credit benefits transferred from tax credit partnership investments, and because no tax benefit is received related to the operating loss or the U.K. tax expense associated with our Lloyd's Syndicate segment. ProAssurance had receivables for federal income taxes of $7.3 million at June 30, 2015 and $1.1 million at December 31, 2014 , both carried as a part of Other Assets. The liability for unrecognized tax benefits was $0.7 million at June 30, 2015 and $0.6 million at December 31, 2014 .

Deferred Policy Acquisition Cos

Deferred Policy Acquisition Costs	6 Months Ended
	Jun. 30, 2015
Insurance [Abstract]
Deferred Policy Acquisition Costs	Deferred Policy Acquisition Costs Policy acquisition costs that are primarily and directly related to the successful production of new and renewal insurance contracts, most significantly agent commissions, premium taxes, and underwriting salaries and benefits, are capitalized as policy acquisition costs and amortized to expense, net of ceding commissions earned, as the related premium revenues are earned. Amortization of DPAC was $19.9 million and $38.9 million for the three and six months ended June 30, 2015 , respectively, and $21.4 million and $41.2 million for the three and six months ended June 30, 2014 , respectively.

Reserve for Losses and Loss Adj

Reserve for Losses and Loss Adjustment Expenses	6 Months Ended
	Jun. 30, 2015
Insurance [Abstract]
Reserve for Losses and Loss Adjustment Expenses	Reserve for Losses and Loss Adjustment Expenses The reserve for losses is established based on estimates of individual claims and actuarially determined estimates of future losses based on ProAssurance’s past loss experience, available industry data and projections as to future claims frequency, severity, inflationary trends and settlement patterns. Estimating the reserve, particularly the reserve appropriate for liability exposures, is a complex process. Claims may be resolved over an extended period of time, often five years or more, and may be subject to litigation. Estimating losses requires ProAssurance to make and revise judgments and assessments regarding multiple uncertainties over an extended period of time. As a result, the reserve estimate may vary significantly from the eventual outcome. The assumptions used in establishing ProAssurance’s reserve are regularly reviewed and updated by management as new data becomes available. Changes to estimates of previously established reserves are included in earnings in the period in which the estimate is changed. During the three and six months ended June 30, 2015 , ProAssurance recognized favorable net loss development of $35.1 million and $68.6 million , respectively, related to prior accident years. The favorable net loss development primarily reflected reductions in the Company's estimates of claims severity related to the 2008 through 2012 accident years. For the three and six months ended June 30, 2014 , ProAssurance recognized favorable net loss development of $42.2 million and $90.4 million , respectively, to reflect reductions in estimated claims severity related to the 2007 through 2011 accident years.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies ProAssurance is involved in various legal actions related to insurance policies and claims handling including, but not limited to, claims asserted by policyholders. These types of legal actions arise in the Company's ordinary course of business and, in accordance with GAAP for insurance entities, are considered as a part of the Company's loss reserving process, which is described in detail under the heading "Losses and Loss Adjustment Expenses" in the Accounting Policies section in Note 1 of the Notes to Consolidated Financial Statements in ProAssurance's 2014 Form 10-K. ProAssurance has funding commitments primarily related to non-public investment entities totaling approximately $143.4 million , expected to be paid as follows: $55.0 million in 2015 , $87.0 million in 2016 and 2017 combined, $0.7 million in 2018 and 2019 combined and $0.7 million thereafter. Of these funding commitments, $13.3 million are related to qualified affordable housing project tax credit investments and are expected to be paid as follows: $11.9 million in 2015, $0.5 million in 2016 and 2017 combined, $0.3 million in 2018 and 2019 combined and $0.6 million thereafter. As a member of Lloyd's and a capital provider to Syndicate 1729 , ProAssurance is required to provide capital, referred to as FAL . At June 30, 2015 , ProAssurance was satisfying the FAL requirement with investment securities on deposit with Lloyd's with a carrying value of $89.5 million (see Note 3 of the Notes to Condensed Consolidated Financial Statements). ProAssurance has issued an unconditional revolving credit agreement of up to £10 million to the Premium Trust Fund of Syndicate 1729 for the purpose of providing working capital. Advances under this Syndicate Credit Agreement bear interest at 8.5% annually, and are repayable upon demand after December 31, 2016. As of June 30, 2015 , the unused commitment under the Syndicate Credit Agreement approximated £2.0 million ( $3.1 million as of June 30, 2015 ).

Long-term Debt

Long-term Debt	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Long-term Debt	Long-term Debt ProAssurance’s outstanding long-term debt consisted of the following: (In thousands) June 30, December 31, Senior notes due 2023, unsecured, interest at 5.3% annually $ 250,000 $ 250,000 Revolving Credit Agreement, outstanding borrowings fully secured, see Note 3, and carried at an interest rate of 0.77%. The interest rate on the borrowing is set at the time the borrowing is initiated or renewed. The current borrowing can be repaid or renewed in October 2015. If renewed, the interest rate will reset. 100,000 — $ 350,000 $ 250,000 Revolving Credit Agreement During June 2015, ProAssurance amended certain terms of its Revolving Credit Agreement to include the following: (1) The available line of credit of $200 million has been expanded to include an additional $50 million accordion feature, which if subscribed successfully, would also be available for use. (2) All borrowings are required to be repaid prior to the expiration date which has been extended to June 19, 2020 . (3) ProAssurance is required to pay a commitment fee, ranging from 12.5 to 25 basis points based on ProAssurance's credit ratings, on the average unused portion of the credit line during the term of the Revolving Credit Agreement . (4) Borrowing under the Revolving Credit Agreement may be secured or unsecured and accrue interest at a selected base rate, adjusted by a margin, which can vary from 0 to 163 basis points, based on ProAssurance's credit rating and whether the borrowing is secured or unsecured. In addition, the financial covenants were amended to replace the original minimum net worth calculation with a requirement that ProAssurance maintain a net worth, excluding AOCI , of at least $1.3 billion . Covenant Compliance There are no financial covenants associated with the Senior Notes due 2023. The Revolving Credit Agreement contains customary representations, covenants and events constituting default, and remedies for default. The Revolving Credit Agreement also defines financial covenants regarding permitted leverage ratios. ProAssurance is currently in compliance with all covenants of the Agreement. Additional Information For additional information regarding ProAssurance's long-term debt, see Note 10 of the Notes to Consolidated Financial Statements included in ProAssurance's December 31, 2014 Form 10-K.

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Shareholders' Equity	Shareholders’ Equity At June 30, 2015 and December 31, 2014 , ProAssurance had 100 million shares of authorized common stock and 50 million shares of authorized preferred stock. The Board has the authority to determine provisions for the issuance of preferred shares, including the number of shares to be issued, the designations, powers, preferences and rights, and the qualifications, limitations or restrictions of such shares. To date, the Board has not approved the issuance of preferred stock. ProAssurance declared cash dividends of $0.31 per share during the first and second quarters of 2015 totaling $33.9 million , which included the second quarter dividend of $16.7 million that was paid in July 2015 . ProAssurance declared cash dividends of $0.30 per share during both the first and second quarters of 2014 totaling $35.5 million , which included the second quarter dividend of $17.6 million that was paid in July 2014 . At June 30, 2015 , Board authorizations for the repurchase of common shares or the retirement of outstanding debt of $158.2 million remained available for use, which included a $100 million increase to the authorization approved by the Board in May 2015. ProAssurance repurchased approximately 2.7 million shares during each six-month period ending June 30, 2015 and 2014 at a total cost of $123.3 million and $122.3 million , respectively. Share-based compensation expense was $2.3 million and $5.0 million for the three and six months ended June 30, 2015 , respectively, and $2.4 million and $5.6 million for the three and six months ended June 30, 2014 , respectively. Related tax benefits were $0.8 million and $1.7 million for the three and six months ended June 30, 2015 , respectively, and $0.8 million and $2.0 million for the three and six months ended June 30, 2014 , respectively. ProAssurance awarded approximately 92,000 restricted share units and 106,500 base performance share units to employees in February 2015 . The fair value of each unit awarded was estimated at $42.73 , equal to the market value of a ProAssurance common share on the date of grant less the estimated present value of dividends during the vesting period. All awards are charged to expense as an increase to equity over the service period (generally the vesting period) associated with the award. Restricted share units and performance share units vest in their entirety at the end of a three -year period following the grant date based on a continuous service requirement and, for performance share units, achievement of a performance objective. Partial vesting is permitted for retirees. A ProAssurance common share is issued for each unit once vesting requirements are met, except that units sufficient to satisfy required tax withholdings are paid in cash. The number of common shares issued for performance share units varies from 75% to 125% of base awards depending upon the degree to which stated performance objectives are achieved. ProAssurance issued approximately 28,000 and 116,000 common shares to employees in February 2015 related to restricted share units and performance share units, respectively, granted in 2012. Performance share units for the 2012 award were issued at levels ranging from 104% to 125% . ProAssurance issued approximately 28,000 common shares to employees in February 2015 as bonus compensation, as approved by the Compensation Committee of the Board. The shares issued were valued at fair value (the market price of a ProAssurance common share on the date of award). Other Comprehensive Income (Loss) and Accumulated Other Comprehensive Income (Loss) For the three and six months ended June 30, 2015 and June 30, 2014 , OCI was primarily comprised of unrealized gains and losses, including non-credit impairment losses, arising during the period related to available-for-sale securities, less reclassification adjustments as shown in the table that follows, net of tax. For the six months ended June 30, 2015 , OCI also included losses related to unrecognized changes in defined benefit plan liabilities of $1.0 million , net of tax, from the reestimation of two defined benefit plans assumed in the Eastern acquisition. Both plans are frozen as to the earning of additional benefits, but the unrecognized plan benefit liability is reestimated annually. At June 30, 2015 and December 31, 2014 , AOCI was primarily comprised of unrealized gains and losses from available-for-sale securities, including non-credit impairments recognized in OCI of $0.8 million and $0.5 million , respectively, net of tax. At June 30, 2015 AOCI also included losses of $1.0 million related to unrecognized changes in defined benefit plan liabilities, net of tax. All tax effects were computed using a 35% rate. OCI and AOCI also included immaterial amounts of foreign currency translation adjustments. Amounts reclassified from accumulated other comprehensive income to net income and the amounts of deferred tax expense (benefit) included in OCI were as follows: Three Months Ended June 30 Six Months Ended June 30 (In thousands) 2015 2014 2015 2014 Reclassifications from AOCI to net income, available-for-sale securities: Realized investment gains (losses) $ 1,956 $ 1,905 $ 2,884 $ 2,606 Tax effect (at 35%) (685 ) (667 ) (1,009 ) (912 ) Net reclassification adjustments $ 1,271 $ 1,238 $ 1,875 $ 1,694 Deferred tax expense (benefit) included in OCI $ (13,481 ) $ 5,932 $ (9,349 ) $ 11,634

Variable Interest Entities

Variable Interest Entities	6 Months Ended
	Jun. 30, 2015
Variable Interest Entities [Abstract]
Variable Interest Entities	Variable Interest Entities ProAssurance holds passive interests in a number of entities that are considered to be VIE s under GAAP guidance. ProAssurance's VIE interests principally consist of interests in LP s/ LLC s formed for the purpose of achieving diversified equity and debt returns. ProAssurance's VIE interests carried as a part of Other investments totaled $36.0 million at June 30, 2015 and $33.3 million at December 31, 2014 . ProAssurance's VIE interests carried as a part of Investment in unconsolidated subsidiaries totaled $72.9 million at June 30, 2015 and $65.0 million at December 31, 2014 . ProAssurance has not consolidated these VIE s because it has either very limited or no power to control the activities that most significantly affect the economic performance of these entities and is not the primary beneficiary of any of the entities. ProAssurance’s involvement with each entity is limited to its direct ownership interest in the entity. ProAssurance has no arrangements with any of the entities to provide other financial support to or on behalf of the entity. At June 30, 2015 , ProAssurance’s maximum loss exposure relative to these investments was limited to the carrying value of ProAssurance’s investment in the VIE .

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Diluted weighted average shares is calculated as basic weighted average shares plus the effect, calculated using the treasury stock method, of assuming that dilutive stock options have been exercised and that performance, restricted and purchase share units have vested. All outstanding stock options, performance, restricted and purchase share units had a dilutive effect for the three and six months ended June 30, 2015 and 2014 .

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Segment Information	Segment Information ProAssurance operates in four segments that are organized around the nature of the products and services provided: Specialty P&C , Workers' Compensation, Lloyd's Syndicate, and Corporate. A description of each segment follows. Specialty P&C is primarily focused on professional liability insurance and medical technology liability insurance. The professional liability business primarily offers professional liability insurance to healthcare providers and institutions and to attorneys and their firms. Medical technology liability insurance is offered for medical technology and life sciences companies that manufacture or distribute products. The Specialty P&C segment cedes certain premium to the Lloyd's Syndicate segment under an agreement with Syndicate 1729 . As discussed below, Syndicate 1729 operating results are reported on a quarter delay. The ceded premium associated with the Syndicate 1729 reinsurance agreement has been reported within the Specialty P&C segment on a similar delay, as this results in the ceded premium being reported in the same period in which the Lloyd's Syndicate segment reports the corresponding assumed premium. Workers' Compensation provides workers' compensation products primarily to employers with 1,000 or fewer employees. The segment also offers alternative market solutions whereby policies written are 100% ceded either to a captive insurer unaffiliated with ProAssurance or to SPC s operated by a wholly owned subsidiary of ProAssurance. The SPC s are fully or partially owned by the employer (or employer group, association or affiliate) insured by the policies ceded. Financial results (underwriting profit or loss, plus investment results) of the SPC s accrue to the owners of that cell. Lloyd's Syndicate includes operating results from ProAssurance's 58% participation in Lloyd's of London Syndicate 1729. Syndicate 1729 underwrites risks over a wide range of property and casualty insurance and reinsurance lines in both the U.S and international markets. The results of this segment are reported on a quarter delay, except that investment results associated with the FAL investments and certain U.S. paid administrative expenses, primarily start-up costs, are reported concurrently as that information is available on an earlier time frame. Corporate includes ProAssurance's U.S. investment operations, interest expense and U.S. income taxes, all of which are managed at the corporate level, non-premium revenues generated outside of our insurance entities, and corporate expenses. The accounting policies of the segments are the same as those described in Note 1 of the Notes to Consolidated Financial Statements in ProAssurance’s December 31, 2014 report on Form 10-K and Note 1 of the Notes to Condensed Consolidated Financial Statements. ProAssurance evaluates performance of its Specialty P&C and Workers' Compensation segments based on before tax underwriting profit or loss, and excludes investment performance. Performance of the Lloyd's Syndicate segment is evaluated based on underwriting profit or loss, plus investment results of investment assets solely allocated to Syndicate 1729 operations, net of U.K. income tax expense. Performance of the Corporate segment is evaluated based on the contribution made to consolidated after tax results. ProAssurance accounts for inter-segment transactions as if the transactions were to third parties at current market prices. Assets are not allocated to segments because investments and other assets are not managed at the segment level. Financial data by segment for the three and six months ended June 30, 2015 and 2014 were as follows: Three Months Ended June 30, 2015 (In thousands) Specialty P&C Workers' Compensation Lloyd's Syndicate Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 112,608 $ 53,581 $ 9,104 $ — $ — $ 175,293 Net investment income — — 189 27,766 — 27,955 Equity in earnings (loss) of unconsolidated subsidiaries — — — 2,420 — 2,420 Net realized gains (losses) — — 4 (3,832 ) (3,828 ) Other income 1,376 163 3 111 (77 ) 1,576 Net losses and loss adjustment expenses (64,054 ) (34,310 ) (5,575 ) — — (103,939 ) Underwriting, policy acquisition and operating expenses* (26,645 ) (15,831 ) (3,964 ) (7,162 ) 77 (53,525 ) Segregated portfolio cells dividend expense — (1,230 ) — — — (1,230 ) Interest expense — — — (3,710 ) — (3,710 ) Income tax benefit (expense) — — (620 ) (7,234 ) — (7,854 ) Segment operating results $ 23,285 $ 2,373 $ (859 ) $ 8,359 $ — $ 33,158 Significant non-cash items Depreciation and amortization $ 1,980 $ 1,429 $ 106 $ 8,068 $ — $ 11,583 Six Months Ended June 30, 2015 (In thousands) Specialty P&C Workers' Compensation Lloyd's Syndicate Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 227,472 $ 104,858 $ 14,862 $ — $ — $ 347,192 Net investment income — — 393 54,865 — 55,258 Equity in earnings (loss) of unconsolidated subsidiaries — — — 4,041 — 4,041 Net realized gains (losses) — — 15 996 — 1,011 Other income 2,874 300 492 268 (189 ) 3,745 Net losses and loss adjustment expenses (133,084 ) (66,412 ) (9,582 ) — — (209,078 ) Underwriting, policy acquisition and operating expenses* (53,806 ) (31,189 ) (7,544 ) (12,531 ) 189 (104,881 ) Segregated portfolio cells dividend expense — (3,414 ) — — — (3,414 ) Interest expense — — — (7,341 ) — (7,341 ) Income tax benefit (expense) — — (620 ) (14,941 ) — (15,561 ) Segment operating results $ 43,456 $ 4,143 $ (1,984 ) $ 25,357 $ — $ 70,972 Significant non-cash items Depreciation and amortization $ 4,143 $ 2,869 $ 236 $ 16,420 $ — $ 23,668 Three Months Ended June 30, 2014 (In thousands) Specialty P&C Workers' Compensation Lloyd's Syndicate Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 124,677 $ 48,674 $ 2,952 $ — $ — $ 176,303 Net investment income — — 109 30,116 — 30,225 Equity in earnings (loss) of unconsolidated subsidiaries — — — 719 — 719 Net realized gains (losses) — — — 13,046 — 13,046 Other income 1,533 184 — 523 (86 ) 2,154 Net losses and loss adjustment expenses (66,664 ) (30,380 ) (1,869 ) — — (98,913 ) Underwriting, policy acquisition and operating expenses* (33,510 ) (15,007 ) (2,538 ) (1,188 ) 86 (52,157 ) Segregated portfolio cells dividend expense — (1,789 ) — — — (1,789 ) Interest expense — — — (3,521 ) — (3,521 ) Income tax benefit (expense) — — — (16,125 ) — (16,125 ) Segment operating results $ 26,036 $ 1,682 $ (1,346 ) $ 23,570 $ — $ 49,942 Significant non-cash items Depreciation and amortization $ 2,297 $ 1,300 $ 172 $ 8,618 $ — $ 12,387 Six Months Ended June 30, 2014 (In thousands) Specialty P&C Workers' Compensation Lloyd's Syndicate Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 250,911 $ 94,169 $ 2,952 $ — $ — $ 348,032 Net investment income — — 124 59,833 — 59,957 Equity in earnings (loss) of unconsolidated subsidiaries — — — 2,470 — 2,470 Net realized gains (losses) — — — 15,790 — 15,790 Other income 3,098 323 — 1,033 (205 ) 4,249 Net losses and loss adjustment expenses (127,624 ) (58,928 ) (1,869 ) — — (188,421 ) Underwriting, policy acquisition and operating expenses* (67,230 ) (30,595 ) (3,414 ) (3,638 ) 205 (104,672 ) Segregated portfolio cells dividend expense — (2,838 ) — — — (2,838 ) Interest expense — — — (7,091 ) — (7,091 ) Income tax benefit (expense) — — — (30,803 ) — (30,803 ) Segment operating results $ 59,155 $ 2,131 $ (2,207 ) $ 37,594 $ — $ 96,673 Significant non-cash items Depreciation and amortization $ 4,374 $ 2,782 $ 172 $ 16,646 $ — $ 23,974 * Beginning with the first quarter of 2015, the operating subsidiaries within the Specialty P&C and Workers' Compensation segments were charged a management fee by the Corporate segment for various management services provided to the subsidiary. Under the new arrangement, the expenses associated with such services are reported as expenses of the Corporate segment, and the management fees charged are reported as an offset to Corporate operating expenses. Prior to 2015, a substantial portion of expenses associated with corporate services were directly allocated to the insurance subsidiaries included in the Specialty P&C segment. The following table provides detailed information regarding ProAssurance's gross premiums earned by product as well as a reconciliation to net premiums earned. All gross premiums earned are from external customers except as noted. ProAssurance's insured risks are primarily within the United States. Three Months Ended June 30 Six Months Ended June 30 (In thousands) 2015 2014 2015 2014 Specialty P&C Segment Gross premiums earned: Healthcare professional liability $ 115,057 $ 119,706 $ 230,887 $ 240,556 Legal professional liability 7,239 7,015 14,439 14,002 Medical technology liability 8,685 9,028 17,657 17,785 Other 388 435 771 1,026 Ceded premiums earned* (18,761 ) (11,507 ) (36,282 ) (22,458 ) Segment net premiums earned $ 112,608 $ 124,677 $ 227,472 $ 250,911 Workers' Compensation Segment Gross premiums earned: Traditional business $ 43,986 $ 39,905 $ 85,989 $ 77,358 Alternative market business 15,885 13,226 31,615 25,908 Ceded premiums earned (6,290 ) (4,457 ) (12,746 ) (9,097 ) Segment net premiums earned $ 53,581 $ 48,674 $ 104,858 $ 94,169 Lloyd's Syndicate Segment Gross premiums earned: Property and casualty* $ 10,323 $ 3,024 $ 16,860 $ 3,024 Ceded premiums earned (1,219 ) (72 ) (1,998 ) (72 ) Segment net premiums earned $ 9,104 $ 2,952 $ 14,862 $ 2,952 Consolidated net premiums earned $ 175,293 $ 176,303 $ 347,192 $ 348,032 *Includes premium ceded from the Specialty P&C Segment to the Lloyd's Syndicate Segment of $3.6 million and $7.0 million for the three and six months ended June 30, 2015 and $0.5 million for both the three and six months ended June 30, 2014 .

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounting Changes Adopted and Not Yet Adopted	Accounting Changes Adopted Reporting Discontinued Operations and Disclosures of Disposals of Components of an Entity Effective for fiscal years beginning after December 15, 2014, the FASB issued guidance regarding the requirements for reporting discontinued operations. Under the new guidance, reporting entities are required to report disposals of business components only if the disposal represents a strategic shift in the entity’s operations that will have a major effect on the entity’s operations and financial results. The new guidance expands disclosure requirements for reported discontinued operations and requires disclosure of pre-tax profit or loss attributable to significant disposals that are not reported as discontinued operations. ProAssurance adopted the guidance as of January 1, 2015. Adoption of the guidance had no effect on ProAssurance’s results of operations or financial position. Disclosures for Investments in Certain Entities that Calculate Net Asset Value per Share (or Its Equivalent) Effective for fiscal years beginning after December 15, 2015, the FASB issued guidance which removed the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The guidance also revised other disclosure requirements for investments measured or eligible to be measured at fair value using the net asset value per share practical expedient. ProAssurance adopted the guidance as of June 30, 2015 as early adoption is permitted. Adoption of the guidance had no effect on ProAssurance's results of operations or financial position as it affected disclosures only. Accounting Changes Not Yet Adopted Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period Effective for fiscal years beginning after December 15, 2015, the FASB issued guidance for share-based payments in which the terms of the award provide that a performance target can be achieved after completion of the requisite service period. The new guidance provides that compensation cost for such awards should be recognized in the period in which it becomes probable that the performance target will be achieved and should represent the compensation cost attributable to the period(s) for which the requisite service has already been rendered. ProAssurance plans to adopt the guidance beginning January 1, 2016. Adoption of the guidance is expected to have no effect on ProAssurance’s results of operations or financial position as ProAssurance has no awards with performance targets extending beyond the requisite service period. Revenue from Contracts with Customers Effective for fiscal years beginning after December 15, 2016, the FASB issued guidance related to revenue from contracts with customers. The core principle of the new guidance is that revenue should be recognized to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ProAssurance plans to adopt the guidance beginning January 1, 2017. As the majority of ProAssurance's revenues come from insurance contracts which fall under the scope of other FASB standards, adoption of the guidance is expected to have no material effect on ProAssurance’s results of operations or financial position. Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern Effective for fiscal years ending after December 15, 2016 and interim periods beginning after December 15, 2016, the FASB issued guidance that establishes principles and definitions related to management's evaluation of whether there is substantial doubt about the organization's ability to continue as a going concern. For each interim and annual reporting period, the new guidance requires management to evaluate the organization's ability to meet its obligations as they are due within one year of the date the financial statements are issued and requires disclosure when there is substantial doubt regarding the organization's ability to continue as a going concern. ProAssurance plans to adopt the guidance on its effective date. Adoption is expected to have no effect on ProAssurance’s results of operations or financial position. Simplifying the Presentation of Debt Issuance Costs Effective for fiscal years beginning after December 15, 2015, the FASB issued guidance related to the presentation of debt issuance costs. The new guidance requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. ProAssurance plans to adopt the guidance beginning January 1, 2016. Adoption of the guidance is not expected to have a material effect on ProAssurance’s results of operations or financial position. Amendments to the Consolidation Analysis Effective for fiscal years beginning after December 15, 2015, the FASB issued additional guidance regarding the consolidation of legal entities such as limited partnerships, limited liability corporations, and securitization structures (collateralized debt obligations, collateralized loan obligations, and mortgage-backed security transactions). The new standard modifies the evaluation of whether or not entities are VIE s and the consolidation analysis of entities involved with VIE s, particularly those having fee arrangements and related party relationships. ProAssurance is in the process of evaluating the effect, if any, of the new guidance on its results of operations and financial position and plans to adopt the guidance beginning January 1, 2016. The effect is not expected to be material. Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement Effective for fiscal years beginning after December 15, 2015, the FASB issued additional guidance regarding accounting for cloud computing arrangements. Under the new guidance, customers participating in cloud computing arrangements that include a software license should account for the software license element of the arrangement consistent with the acquisition of other software licenses. Customers should account for cloud computing arrangements that do not include a software license as a service contract, following existing guidance for service contracts. ProAssurance is in the process of evaluating the effect that the use of the new method would have on its results of operations and financial position and plans to adopt the guidance beginning January 1, 2016. The effect is not expected to be material. Disclosures about Short-Duration Contracts Effective for fiscal years beginning after December 15, 2015, the FASB issued guidance that requires insurance entities to provide detailed discloses relative to the reserve for losses and loss adjustment expenses in annual reporting periods and a roll-forward of the reserve for losses and loss adjustment expenses in interim reporting periods. The guidance also requires disclosures regarding significant changes in the methodologies and assumptions used to calculate the reserve for losses and loss adjustment expenses, including reasons for and the effects of such changes. ProAssurance plans to adopt the guidance beginning January 1, 2016. Adoption of the guidance is not expected to have a material effect on ProAssurance's results of operations or financial position as it affects disclosures only.

Basis of Presentation (Tables)

Basis of Presentation (Tables)	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Other Liabilities	Other liabilities consisted of the following: (In millions) June 30, 2015 December 31, 2014 SPC dividends payable $ 18.6 $ 15.8 Unpaid dividends 16.7 167.7 All other 126.6 137.4 Total other liabilities $ 161.9 $ 320.9

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value	Fair values of assets measured at fair value on a recurring basis as of June 30, 2015 and December 31, 2014 are shown in the following tables. The tables also indicate the fair value hierarchy of the valuation techniques utilized to determine those fair values. For some assets, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. When this is the case, the asset is categorized based on the level of the most significant input to the fair value measurement. Assessments of the significance of a particular input to the fair value measurement require judgment and consideration of factors specific to the assets being valued. June 30, 2015 Fair Value Measurements Using Total (In thousands) Level 1 Level 2 Level 3 Fair Value Assets: Fixed maturities, available for sale U.S. Treasury obligations $ — $ 99,506 $ — $ 99,506 U.S. Government-sponsored enterprise obligations — 29,735 — 29,735 State and municipal bonds — 1,003,611 — 1,003,611 Corporate debt, multiple observable inputs 2,262 1,396,416 — 1,398,678 Corporate debt, limited observable inputs: Other corporate debt, NRSRO ratings available — — 7,927 7,927 Other corporate debt, NRSRO ratings not available — — 541 541 Residential mortgage-backed securities — 267,273 — 267,273 Agency commercial mortgage-backed securities — 11,348 — 11,348 Other commercial mortgage-backed securities — 45,617 — 45,617 Other asset-backed securities — 98,340 4,777 103,117 Equity securities Financial 71,102 — — 71,102 Utilities/Energy 38,219 — — 38,219 Consumer oriented 48,270 — 76 48,346 Industrial 40,846 — — 40,846 Bond funds 79,419 — — 79,419 All other 16,391 13,003 — 29,394 Short-term investments 141,496 2,855 — 144,351 Other investments 3,346 27,294 960 31,600 Total assets categorized within the fair value hierarchy $ 441,351 $ 2,994,998 $ 14,281 $ 3,450,630 LP/LLC interests carried at NAV which approximates fair value. These interests, reported as a part of Investment in unconsolidated subsidiaries, are not categorized within the fair value hierarchy. 149,083 Total assets at fair value $ 3,599,713 December 31, 2014 Fair Value Measurements Using Total (In thousands) Level 1 Level 2 Level 3 Fair Value Assets: Fixed maturities, available for sale U.S. Treasury obligations $ — $ 166,512 $ — $ 166,512 U.S. Government-sponsored enterprise obligations — 39,563 — 39,563 State and municipal bonds — 1,057,590 5,025 1,062,615 Corporate debt, multiple observable inputs — 1,404,020 — 1,404,020 Corporate debt, limited observable inputs: Other corporate debt, NRSRO ratings available — — 10,474 10,474 Other corporate debt, NRSRO ratings not available — — 2,607 2,607 Residential mortgage-backed securities — 276,056 — 276,056 Agency commercial mortgage-backed securities — 15,493 — 15,493 Other commercial mortgage-backed securities — 51,063 — 51,063 Other asset-backed securities — 111,855 4,769 116,624 Equity securities Financial 79,341 — — 79,341 Utilities/Energy 25,629 — — 25,629 Consumer oriented 65,670 — — 65,670 Industrial 55,460 — — 55,460 Bond funds 55,196 — — 55,196 All other 33,186 — — 33,186 Short-term investments 131,199 60 — 131,259 Other investments 6,050 22,908 — 28,958 Total assets categorized within the fair value hierarchy $ 451,731 $ 3,145,120 $ 22,875 $ 3,619,726 LP/LLC interests carried at NAV which approximates fair value. These interests, reported as a part of Investment in unconsolidated subsidiaries, are not categorized within the fair value hierarchy. 133,250 Total assets at fair value $ 3,752,976
Summary of quantitative information about Level 3 fair value measurements	Quantitative Information Regarding Level 3 Valuations Fair Value at (In millions) June 30, 2015 December 31, 2014 Valuation Technique Unobservable Input Range Assets: State and municipal bonds $— $5.0 Market Comparable Comparability Adjustment 0% - 10% (5%) Discounted Cash Flows Comparability Adjustment 0% - 10% (5%) Corporate debt with limited observable inputs $8.5 $13.1 Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Other asset-backed securities $4.8 $4.8 Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Equity securities and Other investments $1.1 $— Discounted Cash Flows Comparability Adjustment 0% - 10% (5%)
Summary of changes in the fair value of assets measured at fair value	The following tables (the Level 3 Tables) present summary information regarding changes in the fair value of assets measured at fair value using Level 3 inputs. June 30, 2015 Level 3 Fair Value Measurements – Assets (In thousands) U.S. Government-sponsored Enterprise Obligations State and Municipal Bonds Corporate Debt Asset-backed Securities Equity Securities and Other Investments Total Balance March 30, 2015 $ — $ 5,025 $ 9,977 $ 4,788 $ — $ 19,790 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income — — — — — — Net realized investment gains (losses) — — — — — — Included in other comprehensive income — (459 ) 21 (11 ) (80 ) (529 ) Purchases — — — — 1,116 1,116 Sales — — (536 ) — — (536 ) Transfers in — — — — — — Transfers out — (4,566 ) (994 ) — — (5,560 ) Balance June 30, 2015 $ — $ — $ 8,468 $ 4,777 $ 1,036 $ 14,281 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ — $ — $ — June 30, 2015 Level 3 Fair Value Measurements – Assets (In thousands) U.S. Government-sponsored Enterprise Obligations State and Municipal Bonds Corporate Debt Asset-backed Securities Equity Securities and Other Investments Total Balance December 31, 2014 $ — $ 5,025 $ 13,081 $ 4,769 $ — $ 22,875 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income — — 17 — — 17 Net realized investment gains (losses) — — 2 — — 2 Included in other comprehensive income — (459 ) (262 ) 8 (80 ) (793 ) Purchases — — 1,515 — 1,116 2,631 Sales — — (836 ) — — (836 ) Transfers in — — — — — — Transfers out — (4,566 ) (5,049 ) — — (9,615 ) Balance June 30, 2015 $ — $ — $ 8,468 $ 4,777 $ 1,036 $ 14,281 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ — $ — $ — June 30, 2014 Level 3 Fair Value Measurements – Assets (In thousands) U.S. Government-sponsored Enterprise Obligations State and Municipal Bonds Corporate Debt Asset-backed Securities Equity Securities and Other Investments Total Balance March 30, 2014 $ 999 $ 7,490 $ 12,381 $ 7,226 $ — $ 28,096 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income — (4 ) 16 — — 12 Net realized investment gains (losses) — — — — — — Included in other comprehensive income 2 (26 ) (2 ) 25 — (1 ) Purchases — — 2,499 1,175 — 3,674 Sales — — (350 ) (61 ) — (411 ) Transfers in — 1,549 — — — 1,549 Transfers out (1,001 ) (1,861 ) — (2,405 ) — (5,267 ) Balance June 30, 2014 $ — $ 7,148 $ 14,544 $ 5,960 $ — $ 27,652 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ — $ — $ — June 30, 2014 Level 3 Fair Value Measurements – Assets (In thousands) U.S. Government-sponsored Enterprise Obligations State and Municipal Bonds Corporate Debt Asset-backed Securities Equity Securities and Other Investments Total Balance December 31, 2013 $ — $ 7,338 $ 14,176 $ 6,814 $ — $ 28,328 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income — (6 ) 32 — — 26 Net realized investment gains (losses) — (95 ) 3 — — (92 ) Included in other comprehensive income 1 42 667 69 — 779 Purchases 1,000 1,861 2,499 3,340 — 8,700 Sales — (257 ) (808 ) (61 ) — (1,126 ) Transfers in — 2,119 — 305 — 2,424 Transfers out (1,001 ) (3,854 ) (2,025 ) (4,507 ) — (11,387 ) Balance June 30, 2014 $ — $ 7,148 $ 14,544 $ 5,960 $ — $ 27,652 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ — $ — $ —
Investments in Limited liability companies and limited partnerships	Investments in unconsolidated subsidiaries at both June 30, 2015 and December 31, 2014 included interests in investment fund LP s/ LLC s that measure fund assets at fair value on a recurring basis and that provide a NAV for the interest. The carrying value of these interests is based on the NAV provided, and was considered to approximate the fair value of the interests. In accordance with GAAP , the fair value of these investments was not classified within the fair value hierarchy. Additional information regarding these investments is as follows: Unfunded Fair Value (In thousands) June 30, June 30, December 31, Investments in LPs/LLCs: Private debt funds (1) $25,946 $ 38,812 $ 37,296 Long equity fund (2) None 7,058 6,747 Long/short equity funds (3) None 25,356 25,301 Non-public equity funds (4) $53,356 65,374 51,811 Multi-strategy fund of funds (5) None 8,534 8,271 Structured credit fund (6) None 3,949 3,824 $ 149,083 $ 133,250 (1) Comprised of interests in two unrelated LP funds that are structured to provide interest distributions primarily through diversified portfolios of private debt instruments. One LP allows redemption by special consent; the other does not permit redemption. Income and capital are to be periodically distributed at the discretion of the LP s over an anticipated time frame that spans from 3 to 8 years. (2) The fund is an LP that holds long equities of public international companies. Redemptions are allowed at the end of any calendar month with a prior notice requirement of 15 days and are paid within 10 days of the end of the calendar month of the redemption request. (3) Comprised of interests in multiple unrelated LP funds. The funds hold primarily long and short North American equities, and target absolute returns using strategies designed to take advantage of event-driven market opportunities. The funds generally permit quarterly or semi-annual capital redemptions subject to notice requirements of 30 to 90 days. For some funds, redemptions above specified thresholds (lowest threshold is 90% ) may be only partially payable until after a fund audit is completed and are then payable within 30 days. (4) Comprised of interests in three unrelated LP funds, each structured to provide capital appreciation through diversified investments in private equity, which can include investments in buyout, venture capital, mezzanine debt, distressed debt and other private equity-oriented LP s. One LP allows redemption by special consent; the others do not permit redemption. Income and capital are to be periodically distributed at the discretion of the LP over time frames that are anticipated to span up to 9 years. (5) This fund is an LLC structured to build and manage low volatility, multi-manager portfolios that have little or no correlation to the broader fixed income and equity security markets. Redemptions are not permitted but the LLC Board is permitted discretion to periodically extend offers to repurchase units of the LLC . (6) This fund is an LP seeking to obtain superior risk-adjusted absolute returns by acquiring and actively managing a diversified portfolio of debt securities, including bonds, loans and other asset-backed instruments. Redemptions are allowed at any quarter-end with a prior notice requirement of 90 days .
Financial instruments not measured at fair value	The following table provides the estimated fair value of our financial instruments that, in accordance with GAAP for the type of investment, are measured using a methodology other than fair value. All fair values provided fall within the Level 3 fair value category. June 30, 2015 December 31, 2014 (In thousands) Carrying Fair Carrying Fair Financial assets: BOLI $ 56,090 $ 56,090 $ 56,381 $ 56,381 Other investments $ 59,510 $ 56,672 $ 57,099 $ 57,994 Other assets $ 23,079 $ 23,052 $ 22,440 $ 22,399 Financial liabilities: Senior notes due 2023 $ 250,000 $ 267,853 $ 250,000 $ 276,503 Revolving credit agreement $ 100,000 $ 100,000 $ — $ — Other liabilities $ 15,259 $ 15,253 $ 14,656 $ 14,645

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2015
Investments, Debt and Equity Securities [Abstract]
Amortized cost and estimated fair value of available-for-sale fixed maturities and equity securities	Available-for-sale securities at June 30, 2015 and December 31, 2014 included the following: June 30, 2015 (In thousands) Amortized Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Fixed maturities U.S. Treasury obligations $ 97,491 $ 2,223 $ 208 $ 99,506 U.S. Government-sponsored enterprise obligations 28,452 1,328 45 29,735 State and municipal bonds 969,667 36,244 2,300 1,003,611 Corporate debt 1,387,556 36,992 17,402 1,407,146 Residential mortgage-backed securities 261,015 7,738 1,480 267,273 Agency commercial mortgage-backed securities 11,135 238 25 11,348 Other commercial mortgage-backed securities 45,032 698 113 45,617 Other asset-backed securities 102,804 368 55 103,117 $ 2,903,152 $ 85,829 $ 21,628 $ 2,967,353 December 31, 2014 (In thousands) Amortized Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Fixed maturities U.S. Treasury obligations $ 163,714 $ 3,785 $ 987 $ 166,512 U.S. Government-sponsored enterprise obligations 38,022 1,641 100 39,563 State and municipal bonds 1,015,555 47,395 335 1,062,615 Corporate debt 1,389,970 44,234 17,103 1,417,101 Residential mortgage-backed securities 266,306 10,198 448 276,056 Agency commercial mortgage-backed securities 15,344 208 59 15,493 Other commercial mortgage-backed securities 50,025 1,137 99 51,063 Other asset-backed securities 116,541 288 205 116,624 $ 3,055,477 $ 108,886 $ 19,336 $ 3,145,027
Schedule of available for sale securities by contractual maturity	The recorded cost basis and estimated fair value of available-for-sale fixed maturities at June 30, 2015 , by contractual maturity, 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. (In thousands) Amortized Due in one Due after Due after Due after Total Fair Fixed maturities, available for sale U.S. Treasury obligations $ 97,491 $ 14,924 $ 69,645 $ 11,744 $ 3,193 $ 99,506 U.S. Government-sponsored enterprise obligations 28,452 2,649 19,404 7,345 337 29,735 State and municipal bonds 969,667 50,386 341,963 443,042 168,220 1,003,611 Corporate debt 1,387,556 106,506 731,107 540,308 29,225 1,407,146 Residential mortgage-backed securities 261,015 267,273 Agency commercial mortgage-backed securities 11,135 11,348 Other commercial mortgage-backed securities 45,032 45,617 Other asset-backed securities 102,804 103,117 $ 2,903,152 $ 2,967,353
Other investments	Other investments at June 30, 2015 and December 31, 2014 were comprised as follows: (In thousands) June 30, December 31, Investments in LPs/LLCs, at cost $ 55,978 $ 53,258 Convertible securities, at fair value 31,600 28,958 Other, principally FHLB capital stock, at cost 3,532 3,841 $ 91,110 $ 86,057
Unconsolidated subsidiaries	ProAssurance holds investments in unconsolidated subsidiaries, accounted for under the equity method. The investments include the following: June 30, 2015 Carrying Value (In thousands) Percentage June 30, December 31, Investment in LPs/LLCs: Qualified affordable housing tax credit partnerships See below $ 126,440 $ 133,143 Other tax credit partnerships See below 3,717 — All other LPs/LLCs < 25% 161,504 143,358 $ 291,661 $ 276,501
Investments held in an unrealized loss position	The following tables provide summarized information with respect to investments held in an unrealized loss position at June 30, 2015 and December 31, 2014 , including the length of time the investment had been held in a continuous unrealized loss position. June 30, 2015 Total Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Fair Unrealized (In thousands) Value Loss Value Loss Value Loss Fixed maturities, available for sale U.S. Treasury obligations $ 31,127 $ 207 $ 25,299 $ 150 $ 5,828 $ 57 U.S. Government-sponsored enterprise obligations 3,447 46 3,447 46 — — State and municipal bonds 130,171 2,300 124,146 2,014 6,025 286 Corporate debt 497,704 17,403 444,860 12,629 52,844 4,774 Residential mortgage-backed securities 82,512 1,480 72,839 1,215 9,673 265 Agency commercial mortgage-backed securities 609 25 187 — 422 25 Other commercial mortgage-backed securities 14,379 114 10,436 92 3,943 22 Other asset-backed securities 27,088 53 18,441 33 8,647 20 $ 787,037 $ 21,628 $ 699,655 $ 16,179 $ 87,382 $ 5,449 Other investments Investments in LPs/LLCs carried at cost $ 29,076 $ 4,552 $ 29,076 $ 4,552 $ — $ — December 31, 2014 Total Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Fair Unrealized (In thousands) Value Loss Value Loss Value Loss Fixed maturities, available for sale U.S. Treasury obligations $ 61,209 $ 987 $ 46,869 $ 617 $ 14,340 $ 370 U.S. Government-sponsored enterprise obligations 6,268 100 2,775 44 3,493 56 State and municipal bonds 39,831 335 18,910 84 20,921 251 Corporate debt 423,107 17,103 326,804 13,236 96,303 3,867 Residential mortgage-backed securities 45,006 448 14,406 31 30,600 417 Agency commercial mortgage-backed securities 4,783 59 70 — 4,713 59 Other commercial mortgage-backed securities 13,860 99 7,005 28 6,855 71 Other asset-backed securities 62,577 205 59,176 109 3,401 96 $ 656,641 $ 19,336 $ 476,015 $ 14,149 $ 180,626 $ 5,187 Other investments Investments in LPs/LLCs carried at cost $ 23,683 $ 3,948 $ 22,265 $ 3,711 $ 1,418 $ 237
Net Investment Income	Net investment income by investment category was as follows: Three Months Ended Six Months Ended (In thousands) 2015 2014 2015 2014 Fixed maturities $ 25,025 $ 28,919 $ 49,984 $ 56,960 Equities 3,456 2,551 6,468 4,818 Short-term and Other investments 396 518 902 1,930 BOLI 474 452 930 898 Investment fees and expenses (1,396 ) (2,215 ) (3,026 ) (4,649 ) Net investment income $ 27,955 $ 30,225 $ 55,258 $ 59,957
Net realized investment gains (losses)	The following table provides detailed information regarding net realized investment gains (losses): Three Months Ended June 30 Six Months Ended June 30 (In thousands) 2015 2014 2015 2014 Total OTTI losses: State and municipal bonds $ — $ — $ — $ (50 ) Corporate debt (1,209 ) — (4,480 ) — Portion recognized in (reclassified from) OCI: Corporate debt 348 — 1,789 — Net impairments recognized in earnings $ (861 ) $ — $ (2,691 ) $ (50 ) Gross realized gains, available-for-sale securities 3,627 2,170 7,640 2,975 Gross realized (losses), available-for-sale securities (810 ) (265 ) (2,065 ) (319 ) Net realized gains (losses), trading securities 9,525 4,819 12,192 18,602 Net realized gains (losses), Other investments 602 68 718 266 Change in unrealized holding gains (losses), trading securities (15,751 ) 5,443 (14,893 ) (7,503 ) Change in unrealized holding gains (losses), convertible securities, carried at fair value (968 ) 811 (698 ) 1,819 Other 808 — 808 — Net realized investment gains (losses) $ (3,828 ) $ 13,046 $ 1,011 $ 15,790
Other than temporary impairment, credit losses recognized in earnings	The following table presents a roll forward of cumulative credit losses recorded in earnings related to impaired debt securities for which a portion of the OTTI was recorded in OCI. Three Months Ended June 30 Six Months Ended June 30 (In thousands) 2015 2014 2015 2014 Balance beginning of period $ 2,062 $ 83 $ 232 $ 83 Additional credit losses recognized during the period, related to securities for which: No OTTI has been previously recognized — — 1,830 — OTTI has been previously recognized 861 — 861 — Reductions due to: Securities sold during the period (realized) (293 ) — (293 ) — Balance June 30 $ 2,630 $ 83 $ 2,630 $ 83
Information regarding sales and purchases of available-for-sale securities	Other information regarding sales and purchases of available-for-sale securities is as follows: Three Months Ended June 30 Six Months Ended June 30 (In millions) 2015 2014 2015 2014 Proceeds from sales (exclusive of maturities and paydowns) $ 95.1 $ 105.7 $ 301.0 $ 122.5 Purchases $ 160.5 $ 235.1 $ 375.6 $ 365.4

Long-term Debt (Tables)

Long-term Debt (Tables)	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	ProAssurance’s outstanding long-term debt consisted of the following: (In thousands) June 30, December 31, Senior notes due 2023, unsecured, interest at 5.3% annually $ 250,000 $ 250,000 Revolving Credit Agreement, outstanding borrowings fully secured, see Note 3, and carried at an interest rate of 0.77%. The interest rate on the borrowing is set at the time the borrowing is initiated or renewed. The current borrowing can be repaid or renewed in October 2015. If renewed, the interest rate will reset. 100,000 — $ 350,000 $ 250,000

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Reclassification adjustments related to available-for-sale securities	Amounts reclassified from accumulated other comprehensive income to net income and the amounts of deferred tax expense (benefit) included in OCI were as follows: Three Months Ended June 30 Six Months Ended June 30 (In thousands) 2015 2014 2015 2014 Reclassifications from AOCI to net income, available-for-sale securities: Realized investment gains (losses) $ 1,956 $ 1,905 $ 2,884 $ 2,606 Tax effect (at 35%) (685 ) (667 ) (1,009 ) (912 ) Net reclassification adjustments $ 1,271 $ 1,238 $ 1,875 $ 1,694 Deferred tax expense (benefit) included in OCI $ (13,481 ) $ 5,932 $ (9,349 ) $ 11,634

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Financial data by segment for the three and six months ended June 30, 2015 and 2014 were as follows: Three Months Ended June 30, 2015 (In thousands) Specialty P&C Workers' Compensation Lloyd's Syndicate Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 112,608 $ 53,581 $ 9,104 $ — $ — $ 175,293 Net investment income — — 189 27,766 — 27,955 Equity in earnings (loss) of unconsolidated subsidiaries — — — 2,420 — 2,420 Net realized gains (losses) — — 4 (3,832 ) (3,828 ) Other income 1,376 163 3 111 (77 ) 1,576 Net losses and loss adjustment expenses (64,054 ) (34,310 ) (5,575 ) — — (103,939 ) Underwriting, policy acquisition and operating expenses* (26,645 ) (15,831 ) (3,964 ) (7,162 ) 77 (53,525 ) Segregated portfolio cells dividend expense — (1,230 ) — — — (1,230 ) Interest expense — — — (3,710 ) — (3,710 ) Income tax benefit (expense) — — (620 ) (7,234 ) — (7,854 ) Segment operating results $ 23,285 $ 2,373 $ (859 ) $ 8,359 $ — $ 33,158 Significant non-cash items Depreciation and amortization $ 1,980 $ 1,429 $ 106 $ 8,068 $ — $ 11,583 Six Months Ended June 30, 2015 (In thousands) Specialty P&C Workers' Compensation Lloyd's Syndicate Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 227,472 $ 104,858 $ 14,862 $ — $ — $ 347,192 Net investment income — — 393 54,865 — 55,258 Equity in earnings (loss) of unconsolidated subsidiaries — — — 4,041 — 4,041 Net realized gains (losses) — — 15 996 — 1,011 Other income 2,874 300 492 268 (189 ) 3,745 Net losses and loss adjustment expenses (133,084 ) (66,412 ) (9,582 ) — — (209,078 ) Underwriting, policy acquisition and operating expenses* (53,806 ) (31,189 ) (7,544 ) (12,531 ) 189 (104,881 ) Segregated portfolio cells dividend expense — (3,414 ) — — — (3,414 ) Interest expense — — — (7,341 ) — (7,341 ) Income tax benefit (expense) — — (620 ) (14,941 ) — (15,561 ) Segment operating results $ 43,456 $ 4,143 $ (1,984 ) $ 25,357 $ — $ 70,972 Significant non-cash items Depreciation and amortization $ 4,143 $ 2,869 $ 236 $ 16,420 $ — $ 23,668 Three Months Ended June 30, 2014 (In thousands) Specialty P&C Workers' Compensation Lloyd's Syndicate Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 124,677 $ 48,674 $ 2,952 $ — $ — $ 176,303 Net investment income — — 109 30,116 — 30,225 Equity in earnings (loss) of unconsolidated subsidiaries — — — 719 — 719 Net realized gains (losses) — — — 13,046 — 13,046 Other income 1,533 184 — 523 (86 ) 2,154 Net losses and loss adjustment expenses (66,664 ) (30,380 ) (1,869 ) — — (98,913 ) Underwriting, policy acquisition and operating expenses* (33,510 ) (15,007 ) (2,538 ) (1,188 ) 86 (52,157 ) Segregated portfolio cells dividend expense — (1,789 ) — — — (1,789 ) Interest expense — — — (3,521 ) — (3,521 ) Income tax benefit (expense) — — — (16,125 ) — (16,125 ) Segment operating results $ 26,036 $ 1,682 $ (1,346 ) $ 23,570 $ — $ 49,942 Significant non-cash items Depreciation and amortization $ 2,297 $ 1,300 $ 172 $ 8,618 $ — $ 12,387 Six Months Ended June 30, 2014 (In thousands) Specialty P&C Workers' Compensation Lloyd's Syndicate Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 250,911 $ 94,169 $ 2,952 $ — $ — $ 348,032 Net investment income — — 124 59,833 — 59,957 Equity in earnings (loss) of unconsolidated subsidiaries — — — 2,470 — 2,470 Net realized gains (losses) — — — 15,790 — 15,790 Other income 3,098 323 — 1,033 (205 ) 4,249 Net losses and loss adjustment expenses (127,624 ) (58,928 ) (1,869 ) — — (188,421 ) Underwriting, policy acquisition and operating expenses* (67,230 ) (30,595 ) (3,414 ) (3,638 ) 205 (104,672 ) Segregated portfolio cells dividend expense — (2,838 ) — — — (2,838 ) Interest expense — — — (7,091 ) — (7,091 ) Income tax benefit (expense) — — — (30,803 ) — (30,803 ) Segment operating results $ 59,155 $ 2,131 $ (2,207 ) $ 37,594 $ — $ 96,673 Significant non-cash items Depreciation and amortization $ 4,374 $ 2,782 $ 172 $ 16,646 $ — $ 23,974 * Beginning with the first quarter of 2015, the operating subsidiaries within the Specialty P&C and Workers' Compensation segments were charged a management fee by the Corporate segment for various management services provided to the subsidiary. Under the new arrangement, the expenses associated with such services are reported as expenses of the Corporate segment, and the management fees charged are reported as an offset to Corporate operating expenses. Prior to 2015, a substantial portion of expenses associated with corporate services were directly allocated to the insurance subsidiaries included in the Specialty P&C segment.
Schedule of Gross Premiums by Product	The following table provides detailed information regarding ProAssurance's gross premiums earned by product as well as a reconciliation to net premiums earned. All gross premiums earned are from external customers except as noted. ProAssurance's insured risks are primarily within the United States. Three Months Ended June 30 Six Months Ended June 30 (In thousands) 2015 2014 2015 2014 Specialty P&C Segment Gross premiums earned: Healthcare professional liability $ 115,057 $ 119,706 $ 230,887 $ 240,556 Legal professional liability 7,239 7,015 14,439 14,002 Medical technology liability 8,685 9,028 17,657 17,785 Other 388 435 771 1,026 Ceded premiums earned* (18,761 ) (11,507 ) (36,282 ) (22,458 ) Segment net premiums earned $ 112,608 $ 124,677 $ 227,472 $ 250,911 Workers' Compensation Segment Gross premiums earned: Traditional business $ 43,986 $ 39,905 $ 85,989 $ 77,358 Alternative market business 15,885 13,226 31,615 25,908 Ceded premiums earned (6,290 ) (4,457 ) (12,746 ) (9,097 ) Segment net premiums earned $ 53,581 $ 48,674 $ 104,858 $ 94,169 Lloyd's Syndicate Segment Gross premiums earned: Property and casualty* $ 10,323 $ 3,024 $ 16,860 $ 3,024 Ceded premiums earned (1,219 ) (72 ) (1,998 ) (72 ) Segment net premiums earned $ 9,104 $ 2,952 $ 14,862 $ 2,952 Consolidated net premiums earned $ 175,293 $ 176,303 $ 347,192 $ 348,032 *Includes premium ceded from the Specialty P&C Segment to the Lloyd's Syndicate Segment of $3.6 million and $7.0 million for the three and six months ended June 30, 2015 and $0.5 million for both the three and six months ended June 30, 2014 .

Basis of Presentation (Details

Basis of Presentation (Details Textual)	6 Months Ended
	Jun. 30, 2015Segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	4

Basis of Presentation Basis of

Basis of Presentation Basis of Presentation (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
SPC dividends payable	$ 18,600	$ 15,800
Unpaid dividends	16,728	167,700	$ 17,607
All other	126,600	137,400
Total other liabilities	$ 161,866	$ 320,853

Fair Value Measurement (Assets

Fair Value Measurement (Assets and Liabilities Measured at Fair Value) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Assets:
Equity securities	$ 307,326	$ 314,482
Level 3 [Member] | State and municipal bonds [Member]
Assets:
Total assets at fair value	0	5,000
Level 3 [Member] | Other asset-backed securities [Member]
Assets:
Total assets at fair value	4,800	4,800
Fair Value, Measurements, Recurring [Member]
Assets:
Other investments	31,600	28,958
Total assets at fair value	3,450,630	3,619,726
Fair Value, Measurements, Recurring [Member] | U.S. Treasury obligations [Member]
Assets:
Fixed maturities, available for sale	99,506	166,512
Fair Value, Measurements, Recurring [Member] | U.S. Government-sponsored enterprise obligations [Member]
Assets:
Fixed maturities, available for sale	29,735	39,563
Fair Value, Measurements, Recurring [Member] | State and municipal bonds [Member]
Assets:
Fixed maturities, available for sale	1,003,611	1,062,615
Fair Value, Measurements, Recurring [Member] | Corporate debt, multiple observable inputs [Member]
Assets:
Fixed maturities, available for sale	1,398,678	1,404,020
Fair Value, Measurements, Recurring [Member] | Other corporate debt, NRSRO ratings available [Member]
Assets:
Fixed maturities, available for sale	7,927	10,474
Fair Value, Measurements, Recurring [Member] | Other corporate debt, NRSRO ratings not available [Member]
Assets:
Fixed maturities, available for sale	541	2,607
Fair Value, Measurements, Recurring [Member] | Residential mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	267,273	276,056
Fair Value, Measurements, Recurring [Member] | Agency commercial mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	11,348	15,493
Fair Value, Measurements, Recurring [Member] | Other commercial mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	45,617	51,063
Fair Value, Measurements, Recurring [Member] | Other asset-backed securities [Member]
Assets:
Fixed maturities, available for sale	103,117	116,624
Fair Value, Measurements, Recurring [Member] | Financial [Member]
Assets:
Equity securities	71,102	79,341
Fair Value, Measurements, Recurring [Member] | Utilities/Energy [Member]
Assets:
Equity securities	38,219	25,629
Fair Value, Measurements, Recurring [Member] | Consumer oriented [Member]
Assets:
Equity securities	48,346	65,670
Fair Value, Measurements, Recurring [Member] | Industrial [Member]
Assets:
Equity securities	40,846	55,460
Fair Value, Measurements, Recurring [Member] | Bond funds [Member]
Assets:
Equity securities	79,419	55,196
Fair Value, Measurements, Recurring [Member] | All other [Member]
Assets:
Equity securities	29,394	33,186
Fair Value, Measurements, Recurring [Member] | Short-term Investments [Member]
Assets:
Short-term investments	144,351	131,259
Fair Value, Measurements, Recurring [Member] | Adjustments for New Accounting Principle, Early Adoption [Member]
Assets:
LP/LLC interests carried at NAV which approximates fair value. These interests, reported as a part of Investment in unconsolidated subsidiaries, are not categorized within the fair value hierarchy.	149,083	133,250
Total assets at fair value	3,599,713	3,752,976
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Assets:
Other investments	3,346	6,050
Total assets at fair value	441,351	451,731
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | U.S. Treasury obligations [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | U.S. Government-sponsored enterprise obligations [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | State and municipal bonds [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Corporate debt, multiple observable inputs [Member]
Assets:
Fixed maturities, available for sale	2,262	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Other corporate debt, NRSRO ratings available [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Other corporate debt, NRSRO ratings not available [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Residential mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Agency commercial mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Other commercial mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Other asset-backed securities [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Financial [Member]
Assets:
Equity securities	71,102	79,341
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Utilities/Energy [Member]
Assets:
Equity securities	38,219	25,629
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Consumer oriented [Member]
Assets:
Equity securities	48,270	65,670
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Industrial [Member]
Assets:
Equity securities	40,846	55,460
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Bond funds [Member]
Assets:
Equity securities	79,419	55,196
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | All other [Member]
Assets:
Equity securities	16,391	33,186
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Short-term Investments [Member]
Assets:
Short-term investments	141,496	131,199
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Assets:
Other investments	27,294	22,908
Total assets at fair value	2,994,998	3,145,120
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | U.S. Treasury obligations [Member]
Assets:
Fixed maturities, available for sale	99,506	166,512
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | U.S. Government-sponsored enterprise obligations [Member]
Assets:
Fixed maturities, available for sale	29,735	39,563
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | State and municipal bonds [Member]
Assets:
Fixed maturities, available for sale	1,003,611	1,057,590
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Corporate debt, multiple observable inputs [Member]
Assets:
Fixed maturities, available for sale	1,396,416	1,404,020
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Other corporate debt, NRSRO ratings available [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Other corporate debt, NRSRO ratings not available [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Residential mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	267,273	276,056
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Agency commercial mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	11,348	15,493
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Other commercial mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	45,617	51,063
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Other asset-backed securities [Member]
Assets:
Fixed maturities, available for sale	98,340	111,855
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Financial [Member]
Assets:
Equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Utilities/Energy [Member]
Assets:
Equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Consumer oriented [Member]
Assets:
Equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Industrial [Member]
Assets:
Equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Bond funds [Member]
Assets:
Equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | All other [Member]
Assets:
Equity securities	13,003	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Short-term Investments [Member]
Assets:
Short-term investments	2,855	60
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Assets:
Other investments	960	0
Total assets at fair value	14,281	22,875
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | U.S. Treasury obligations [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | U.S. Government-sponsored enterprise obligations [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | State and municipal bonds [Member]
Assets:
Fixed maturities, available for sale	0	5,025
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Corporate debt, multiple observable inputs [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Other corporate debt, NRSRO ratings available [Member]
Assets:
Fixed maturities, available for sale	7,927	10,474
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Other corporate debt, NRSRO ratings not available [Member]
Assets:
Fixed maturities, available for sale	541	2,607
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Residential mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Agency commercial mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Other commercial mortgage-backed securities [Member]
Assets:
Fixed maturities, available for sale	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Other asset-backed securities [Member]
Assets:
Fixed maturities, available for sale	4,777	4,769
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Financial [Member]
Assets:
Equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Utilities/Energy [Member]
Assets:
Equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Consumer oriented [Member]
Assets:
Equity securities	76	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Industrial [Member]
Assets:
Equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Bond funds [Member]
Assets:
Equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | All other [Member]
Assets:
Equity securities	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Short-term Investments [Member]
Assets:
Short-term investments	$ 0	$ 0

Fair Value Measurement (Quantit

Fair Value Measurement (Quantitative Information Regarding Level 3 Valuations) (Details) - Level 3 [Member] - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
State and municipal bonds [Member]
Assets:
Assets, Fair Value	$ 0	$ 5
State and municipal bonds [Member] | Market comparable securities valuation technique [Member] | Minimum [Member]
Assets:
Comparability Adjustment	0.00%
State and municipal bonds [Member] | Market comparable securities valuation technique [Member] | Maximum [Member]
Assets:
Comparability Adjustment	10.00%
State and municipal bonds [Member] | Market comparable securities valuation technique [Member] | Weighted Average [Member]
Assets:
Comparability Adjustment	5.00%
State and municipal bonds [Member] | Discount cash flows valuation technique [Member] | Minimum [Member]
Assets:
Comparability Adjustment	0.00%
State and municipal bonds [Member] | Discount cash flows valuation technique [Member] | Maximum [Member]
Assets:
Comparability Adjustment	10.00%
State and municipal bonds [Member] | Discount cash flows valuation technique [Member] | Weighted Average [Member]
Assets:
Comparability Adjustment	5.00%
Corporate debt with limited observable inputs [Member]
Assets:
Assets, Fair Value	$ 8.5	13.1
Corporate debt with limited observable inputs [Member] | Market comparable securities valuation technique [Member] | Minimum [Member]
Assets:
Comparability Adjustment	0.00%
Corporate debt with limited observable inputs [Member] | Market comparable securities valuation technique [Member] | Maximum [Member]
Assets:
Comparability Adjustment	5.00%
Corporate debt with limited observable inputs [Member] | Market comparable securities valuation technique [Member] | Weighted Average [Member]
Assets:
Comparability Adjustment	2.50%
Corporate debt with limited observable inputs [Member] | Discount cash flows valuation technique [Member] | Minimum [Member]
Assets:
Comparability Adjustment	0.00%
Corporate debt with limited observable inputs [Member] | Discount cash flows valuation technique [Member] | Maximum [Member]
Assets:
Comparability Adjustment	5.00%
Corporate debt with limited observable inputs [Member] | Discount cash flows valuation technique [Member] | Weighted Average [Member]
Assets:
Comparability Adjustment	2.50%
Other asset-backed securities [Member]
Assets:
Assets, Fair Value	$ 4.8	4.8
Other asset-backed securities [Member] | Market comparable securities valuation technique [Member] | Minimum [Member]
Assets:
Comparability Adjustment	0.00%
Other asset-backed securities [Member] | Market comparable securities valuation technique [Member] | Maximum [Member]
Assets:
Comparability Adjustment	5.00%
Other asset-backed securities [Member] | Market comparable securities valuation technique [Member] | Weighted Average [Member]
Assets:
Comparability Adjustment	2.50%
Other asset-backed securities [Member] | Discount cash flows valuation technique [Member] | Minimum [Member]
Assets:
Comparability Adjustment	0.00%
Other asset-backed securities [Member] | Discount cash flows valuation technique [Member] | Maximum [Member]
Assets:
Comparability Adjustment	5.00%
Other asset-backed securities [Member] | Discount cash flows valuation technique [Member] | Weighted Average [Member]
Assets:
Comparability Adjustment	2.50%
Equity securities and other investments [Member]
Assets:
Assets, Fair Value	$ 1.1	$ 0
Equity securities and other investments [Member] | Discount cash flows valuation technique [Member] | Minimum [Member]
Assets:
Comparability Adjustment	0.00%
Equity securities and other investments [Member] | Discount cash flows valuation technique [Member] | Maximum [Member]
Assets:
Comparability Adjustment	10.00%
Equity securities and other investments [Member] | Discount cash flows valuation technique [Member] | Weighted Average [Member]
Assets:
Comparability Adjustment	5.00%

Fair Value Measurement (Level 3

Fair Value Measurement (Level 3 Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation:
Beginning Balance	$ 19,790	$ 28,096	$ 22,875	$ 28,328
Included in earnings, as a part of:
Included in other comprehensive income	(529)	(1)	(793)	779
Purchases	1,116	3,674	2,631	8,700
Sales	(536)	(411)	(836)	(1,126)
Transfers in	0	1,549	0	2,424
Transfers out	(5,560)	(5,267)	(9,615)	(11,387)
Ending Balance	14,281	27,652	14,281	27,652
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	0	0	0	0
U.S. Government-sponsored enterprise obligations [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation:
Beginning Balance	0	999	0	0
Included in earnings, as a part of:
Included in other comprehensive income	0	2	0	1
Purchases	0	0	0	1,000
Sales	0	0	0	0
Transfers in	0	0	0	0
Transfers out	0	(1,001)	0	(1,001)
Ending Balance	0	0	0	0
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	0	0	0	0
State and municipal bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation:
Beginning Balance	5,025	7,490	5,025	7,338
Included in earnings, as a part of:
Included in other comprehensive income	(459)	(26)	(459)	42
Purchases	0	0	0	1,861
Sales	0	0	0	(257)
Transfers in	0	1,549	0	2,119
Transfers out	(4,566)	(1,861)	(4,566)	(3,854)
Ending Balance	0	7,148	0	7,148
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	0	0	0	0
Corporate debt [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation:
Beginning Balance	9,977	12,381	13,081	14,176
Included in earnings, as a part of:
Included in other comprehensive income	21	(2)	(262)	667
Purchases	0	2,499	1,515	2,499
Sales	(536)	(350)	(836)	(808)
Transfers in	0	0	0	0
Transfers out	(994)	0	(5,049)	(2,025)
Ending Balance	8,468	14,544	8,468	14,544
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	0	0	0	0
Asset-backed securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation:
Beginning Balance	4,788	7,226	4,769	6,814
Included in earnings, as a part of:
Included in other comprehensive income	(11)	25	8	69
Purchases	0	1,175	0	3,340
Sales	0	(61)	0	(61)
Transfers in	0	0	0	305
Transfers out	0	(2,405)	0	(4,507)
Ending Balance	4,777	5,960	4,777	5,960
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	0	0	0	0
Equity securities and other investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation:
Beginning Balance	0	0	0	0
Included in earnings, as a part of:
Included in other comprehensive income	(80)	0	(80)	0
Purchases	1,116	0	1,116	0
Sales	0	0	0	0
Transfers in	0	0	0	0
Transfers out	0	0	0	0
Ending Balance	1,036	0	1,036	0
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	0	0	0	0
Net investment Income [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	12	17	26
Net investment Income [Member] | U.S. Government-sponsored enterprise obligations [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	0	0	0
Net investment Income [Member] | State and municipal bonds [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	(4)	0	(6)
Net investment Income [Member] | Corporate debt [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	16	17	32
Net investment Income [Member] | Asset-backed securities [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	0	0	0
Net investment Income [Member] | Equity securities and other investments [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	0	0	0
Net realized investment gains (losses) [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	0	2	(92)
Net realized investment gains (losses) [Member] | U.S. Government-sponsored enterprise obligations [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	0	0	0
Net realized investment gains (losses) [Member] | State and municipal bonds [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	0	0	(95)
Net realized investment gains (losses) [Member] | Corporate debt [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	0	2	3
Net realized investment gains (losses) [Member] | Asset-backed securities [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	0	0	0	0
Net realized investment gains (losses) [Member] | Equity securities and other investments [Member]
Included in earnings, as a part of:
Total gains (losses) realized and unrealized, included in earnings	$ 0	$ 0	$ 0	$ 0

Fair Value Measurement (Narrati

Fair Value Measurement (Narrative) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Credit Derivatives [Line Items]
Fair value level 1 to level 2 transfers	$ 0	$ 0
Fair value level 2 to level 1 transfers	$ 0	$ 0
Corporate debt with limited observable inputs [Member] | A- Rating [Member]
Credit Derivatives [Line Items]
Credit rating	94.00%

Fair Value Measurement (Investm

Fair Value Measurement (Investments in LLCs and Limited Partnerships) (Details) - USD ($) $ in Thousands		Jun. 30, 2015	Dec. 31, 2014
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments in LPs/LLCs fair value		$ 149,083	$ 133,250
Private debt fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments LPs/LLCs unfunded commitments	[1]	25,946
Investments in LPs/LLCs fair value	[1]	38,812	37,296
Long equity fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments LPs/LLCs unfunded commitments	[2]	0
Investments in LPs/LLCs fair value	[2]	7,058	6,747
Long/Short equity funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments LPs/LLCs unfunded commitments	[3]	0
Investments in LPs/LLCs fair value	[3]	25,356	25,301
Non-public equity funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments LPs/LLCs unfunded commitments	[4]	53,356
Investments in LPs/LLCs fair value	[4]	65,374	51,811
Multi-Strategy Fund of Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments LPs/LLCs unfunded commitments	[5]	0
Investments in LPs/LLCs fair value	[5]	8,534	8,271
Structured Credit Fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investments LPs/LLCs unfunded commitments	[6]	0
Investments in LPs/LLCs fair value	[6]	$ 3,949	$ 3,824
[1]	Comprised of interests in two unrelated LP funds that are structured to provide interest distributions primarily through diversified portfolios of private debt instruments. One LP allows redemption by special consent; the other does not permit redemption. Income and capital are to be periodically distributed at the discretion of the LPs over an anticipated time frame that spans from 3 to 8 years.
[2]	The fund is an LP that holds long equities of public international companies. Redemptions are allowed at the end of any calendar month with a prior notice requirement of 15 days and are paid within 10 days of the end of the calendar month of the redemption request.
[3]	Comprised of interests in multiple unrelated LP funds. The funds hold primarily long and short North American equities, and target absolute returns using strategies designed to take advantage of event-driven market opportunities. The funds generally permit quarterly or semi-annual capital redemptions subject to notice requirements of 30 to 90 days. For some funds, redemptions above specified thresholds (lowest threshold is 90%) may be only partially payable until after a fund audit is completed and are then payable within 30 days.
[4]	Comprised of interests in three unrelated LP funds, each structured to provide capital appreciation through diversified investments in private equity, which can include investments in buyout, venture capital, mezzanine debt, distressed debt and other private equity-oriented LPs. One LP allows redemption by special consent; the others do not permit redemption. Income and capital are to be periodically distributed at the discretion of the LP over time frames that are anticipated to span up to 9 years.
[5]	This fund is an LLC structured to build and manage low volatility, multi-manager portfolios that have little or no correlation to the broader fixed income and equity security markets. Redemptions are not permitted but the LLC Board is permitted discretion to periodically extend offers to repurchase units of the LLC.
[6]	This fund is an LP seeking to obtain superior risk-adjusted absolute returns by acquiring and actively managing a diversified portfolio of debt securities, including bonds, loans and other asset-backed instruments. Redemptions are allowed at any quarter-end with a prior notice requirement of 90 days.

Fair Value Measurement (Inves33

Fair Value Measurement (Investments in LLCs and Limited Partnerships Footnote) (Details) - Jun. 30, 2015	Total
Long equity fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investment redemption notice period	15 days
Non-public equity funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Liquidating investments remaining period	9 years
Structured Credit Fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investment redemption notice period	90 days
Minimum [Member] | Secured debt fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Liquidating investments remaining period	3 years
Minimum [Member] | Long/Short Equity Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investment redemption notice period	30 days
Redemption percentage of LP at NAV for which initial payment is limited	90.00%
Maximum [Member] | Secured debt fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Liquidating investments remaining period	8 years
Maximum [Member] | Long equity fund [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Payment period for redemption of LP valued at NAV	10 days
Maximum [Member] | Long/Short Equity Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investment redemption notice period	90 days
Payment period for redemption of LP valued at NAV	30 days

Fair Value Measurement (Methodo

Fair Value Measurement (Methodologies Other Than Fair Value) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Financial assets:
BOLI	$ 56,090	$ 56,381
Other investments	91,110	86,057
Other assets	98,648	93,263
Financial liabilities:
Senior notes due 2023	350,000	250,000
Total other liabilities	161,866	320,853
Not Measured At Fair Value [Member] | Carrying Value [Member]
Financial assets:
BOLI	56,090	56,381
Other investments	59,510	57,099
Other assets	23,079	22,440
Financial liabilities:
Total other liabilities	15,259	14,656
Not Measured At Fair Value [Member] | Carrying Value [Member] | Senior notes due 2023 [Member]
Financial liabilities:
Senior notes due 2023	250,000	250,000
Not Measured At Fair Value [Member] | Carrying Value [Member] | Revolving Credit Facility [Member]
Financial liabilities:
Senior notes due 2023	100,000	0
Not Measured At Fair Value [Member] | Level 3 [Member] | Fair Value [Member]
Financial assets:
BOLI	56,090	56,381
Other investments	56,672	57,994
Other assets	23,052	22,399
Financial liabilities:
Total other liabilities	15,253	14,645
Not Measured At Fair Value [Member] | Level 3 [Member] | Fair Value [Member] | Senior notes due 2023 [Member]
Financial liabilities:
Senior notes due 2023	267,853	276,503
Not Measured At Fair Value [Member] | Level 3 [Member] | Fair Value [Member] | Revolving Credit Facility [Member]
Financial liabilities:
Senior notes due 2023	$ 100,000	$ 0

Investments (Available-For-Sale

Investments (Available-For-Sale Securities) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
U.S. Treasury obligations [Member]
Fixed maturities, available for sale
Amortized Cost	$ 97,491	$ 163,714
Gross Unrealized Gains	2,223	3,785
Gross Unrealized Losses	208	987
Estimated Fair Value	99,506	166,512
U.S. Government-sponsored enterprise obligations [Member]
Fixed maturities, available for sale
Amortized Cost	28,452	38,022
Gross Unrealized Gains	1,328	1,641
Gross Unrealized Losses	45	100
Estimated Fair Value	29,735	39,563
State and municipal bonds [Member]
Fixed maturities, available for sale
Amortized Cost	969,667	1,015,555
Gross Unrealized Gains	36,244	47,395
Gross Unrealized Losses	2,300	335
Estimated Fair Value	1,003,611	1,062,615
Corporate debt [Member]
Fixed maturities, available for sale
Amortized Cost	1,387,556	1,389,970
Gross Unrealized Gains	36,992	44,234
Gross Unrealized Losses	17,402	17,103
Estimated Fair Value	1,407,146	1,417,101
Residential mortgage-backed securities [Member]
Fixed maturities, available for sale
Amortized Cost	261,015	266,306
Gross Unrealized Gains	7,738	10,198
Gross Unrealized Losses	1,480	448
Estimated Fair Value	267,273	276,056
Agency commercial mortgage-backed securities [Member]
Fixed maturities, available for sale
Amortized Cost	11,135	15,344
Gross Unrealized Gains	238	208
Gross Unrealized Losses	25	59
Estimated Fair Value	11,348	15,493
Other commercial mortgage-backed securities [Member]
Fixed maturities, available for sale
Amortized Cost	45,032	50,025
Gross Unrealized Gains	698	1,137
Gross Unrealized Losses	113	99
Estimated Fair Value	45,617	51,063
Other asset-backed securities [Member]
Fixed maturities, available for sale
Amortized Cost	102,804	116,541
Gross Unrealized Gains	368	288
Gross Unrealized Losses	55	205
Estimated Fair Value	103,117	116,624
Debt Securities [Member]
Fixed maturities, available for sale
Amortized Cost	2,903,152	3,055,477
Gross Unrealized Gains	85,829	108,886
Gross Unrealized Losses	21,628	19,336
Estimated Fair Value	$ 2,967,353	$ 3,145,027

Investments (Available For Sale

Investments (Available For Sale Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
U.S. Treasury obligations [Member]
Fixed maturities, available for sale
Amortized Cost	$ 97,491	$ 163,714
Due in one year or less	14,924
Due after one year through five years	69,645
Due after five years through ten years	11,744
Due after ten years	3,193
Estimated Fair Value	99,506	166,512
U.S. Government-sponsored enterprise obligations [Member]
Fixed maturities, available for sale
Amortized Cost	28,452	38,022
Due in one year or less	2,649
Due after one year through five years	19,404
Due after five years through ten years	7,345
Due after ten years	337
Estimated Fair Value	29,735	39,563
State and municipal bonds [Member]
Fixed maturities, available for sale
Amortized Cost	969,667	1,015,555
Due in one year or less	50,386
Due after one year through five years	341,963
Due after five years through ten years	443,042
Due after ten years	168,220
Estimated Fair Value	1,003,611	1,062,615
Corporate debt [Member]
Fixed maturities, available for sale
Amortized Cost	1,387,556	1,389,970
Due in one year or less	106,506
Due after one year through five years	731,107
Due after five years through ten years	540,308
Due after ten years	29,225
Estimated Fair Value	1,407,146	1,417,101
Residential mortgage-backed securities [Member]
Fixed maturities, available for sale
Amortized Cost	261,015	266,306
Estimated Fair Value	267,273	276,056
Agency commercial mortgage-backed securities [Member]
Fixed maturities, available for sale
Amortized Cost	11,135	15,344
Estimated Fair Value	11,348	15,493
Other commercial mortgage-backed securities [Member]
Fixed maturities, available for sale
Amortized Cost	45,032	50,025
Estimated Fair Value	45,617	51,063
Other asset-backed securities [Member]
Fixed maturities, available for sale
Amortized Cost	102,804	116,541
Estimated Fair Value	103,117	116,624
Debt Securities [Member]
Fixed maturities, available for sale
Amortized Cost	2,903,152	3,055,477
Estimated Fair Value	$ 2,967,353	$ 3,145,027

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015USD ($)SecurityAffiliateinvestment_interestIssuer	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)SecurityAffiliateinvestment_interestIssuer	Jun. 30, 2014USD ($)	Dec. 31, 2014USD ($)SecurityIssuer
Schedule of Available-for-sale Securities [Line Items]
Number of investment affiliates exceeding shareholder's equity ten percent threshold limit | Affiliate	0		0
Threshold limit of investments based on shareholders' equity	10.00%		10.00%
Securities on deposit with state insurance departments	$ 49,600		$ 49,600
Business owned life insurance cost	33,000		33,000
Investment in unconsolidated subsidiaries	291,661		291,661		$ 276,501
Investments in LPs/LLCs fair value	149,083		149,083		133,250
Real estate investment property	12,400		12,400		10,100
Amortization of operation losses, related to affordable housing tax project tax credits	2,600	$ 2,400	5,200	$ 4,000
Net impairments recognized in earnings	861	0	2,691	50
Portion of OTTI losses recognized in (reclassified from) other comprehensive income before taxes	$ 348	0	$ 1,789	0
Tax Credit Partnerships Almost 100% Ownership [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of tax credit partnerships almost 100% ownership percentage | investment_interest	2		2
Investment in unconsolidated subsidiaries	$ 55,700		$ 55,700
Tax Credit Partnerships Less Than 20% Ownership [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment in unconsolidated subsidiaries	70,700		70,700
Other tax credit partnerships [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment in unconsolidated subsidiaries	$ 3,717		$ 3,717		$ 0
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Period for federal home loan bank stock liquidation process			5 years
Maximum [Member] | Tax Credit Partnerships Almost 100% Ownership [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage Ownership	100.00%		100.00%
Maximum [Member] | Tax Credit Partnerships Less Than 20% Ownership [Member]
Schedule of Available-for-sale Securities [Line Items]
Percentage Ownership	20.00%		20.00%
Fixed maturities [Member]
Schedule of Available-for-sale Securities [Line Items]
Required FAL Deposit	$ 89,300		$ 89,300
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Required FAL Deposit	$ 200		$ 200
Non Government-Backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of debt securities in unrealized loss position | Security	651		651		588
Debt securities in unrealized loss position as percentage of total debt securities held	23.50%		23.50%		20.50%
Number of issuers in unrealized loss position | Issuer	475		475		434
Single greatest unrealized loss position	$ 1,000		$ 1,000		$ 1,700
Second greatest unrealized loss position	800		800		$ 700
Corporate debt with limited observable inputs [Member]
Schedule of Available-for-sale Securities [Line Items]
Portion of OTTI losses recognized in (reclassified from) other comprehensive income before taxes	348	$ 0	1,789	$ 0
Revolving Credit Facility [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities pledged as collateral	$ 126,400		$ 126,400

Investments (Other Investments)

Investments (Other Investments) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Other Investments
Other investments	$ 91,110	$ 86,057
Investments in LPs/LLCs, at cost [Member]
Other Investments
Other investments	55,978	53,258
Convertible securities, at fair value [Member]
Other Investments
Other investments	31,600	28,958
Other, principally FHLB capital stock at cost [Member]
Other Investments
Other investments	$ 3,532	$ 3,841

Investments (Unconsolidated Sub

Investments (Unconsolidated Subsidiaries) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Unconsolidated Subsidiaries
Investment in unconsolidated subsidiaries	$ 291,661	$ 276,501
Qualified affordable housing tax credit partnerships [Member]
Unconsolidated Subsidiaries
Investment in unconsolidated subsidiaries	126,440	133,143
Other tax credit partnerships [Member]
Unconsolidated Subsidiaries
Investment in unconsolidated subsidiaries	3,717	0
All Other LPs/LLCs [Member]
Unconsolidated Subsidiaries
Investment in unconsolidated subsidiaries	$ 161,504	$ 143,358
All Other LPs/LLCs [Member] | Maximum [Member]
Unconsolidated Subsidiaries
Percentage Ownership	25.00%

Investments (Investments Held i

Investments (Investments Held in a Loss Position) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Investments in LPs/LLCs [Member]
Investments held in an unrealized loss position
Fair Value	$ 29,076	$ 23,683
Unrealized Loss	4,552	3,948
Less than 12 months, Fair Value	29,076	22,265
Less than 12 months, Unrealized Loss	4,552	3,711
More than 12 months, Fair Value		1,418
More than 12 months, Unrealized Loss		237
U.S. Treasury obligations [Member]
Investments held in an unrealized loss position
Fair Value	31,127	61,209
Unrealized Loss	207	987
Less than 12 months, Fair Value	25,299	46,869
Less than 12 months, Unrealized Loss	150	617
More than 12 months, Fair Value	5,828	14,340
More than 12 months, Unrealized Loss	57	370
US Government-sponsored Enterprises Debt Securities [Member]
Investments held in an unrealized loss position
Fair Value	3,447	6,268
Unrealized Loss	46	100
Less than 12 months, Fair Value	3,447	2,775
Less than 12 months, Unrealized Loss	46	44
More than 12 months, Fair Value	0	3,493
More than 12 months, Unrealized Loss	0	56
State and municipal bonds [Member]
Investments held in an unrealized loss position
Fair Value	130,171	39,831
Unrealized Loss	2,300	335
Less than 12 months, Fair Value	124,146	18,910
Less than 12 months, Unrealized Loss	2,014	84
More than 12 months, Fair Value	6,025	20,921
More than 12 months, Unrealized Loss	286	251
Corporate debt [Member]
Investments held in an unrealized loss position
Fair Value	497,704	423,107
Unrealized Loss	17,403	17,103
Less than 12 months, Fair Value	444,860	326,804
Less than 12 months, Unrealized Loss	12,629	13,236
More than 12 months, Fair Value	52,844	96,303
More than 12 months, Unrealized Loss	4,774	3,867
Residential mortgage-backed securities [Member]
Investments held in an unrealized loss position
Fair Value	82,512	45,006
Unrealized Loss	1,480	448
Less than 12 months, Fair Value	72,839	14,406
Less than 12 months, Unrealized Loss	1,215	31
More than 12 months, Fair Value	9,673	30,600
More than 12 months, Unrealized Loss	265	417
Agency commercial mortgage-backed securities [Member]
Investments held in an unrealized loss position
Fair Value	609	4,783
Unrealized Loss	25	59
Less than 12 months, Fair Value	187	70
Less than 12 months, Unrealized Loss	0	0
More than 12 months, Fair Value	422	4,713
More than 12 months, Unrealized Loss	25	59
Other commercial mortgage-backed securities [Member]
Investments held in an unrealized loss position
Fair Value	14,379	13,860
Unrealized Loss	114	99
Less than 12 months, Fair Value	10,436	7,005
Less than 12 months, Unrealized Loss	92	28
More than 12 months, Fair Value	3,943	6,855
More than 12 months, Unrealized Loss	22	71
Other asset-backed securities [Member]
Investments held in an unrealized loss position
Fair Value	27,088	62,577
Unrealized Loss	53	205
Less than 12 months, Fair Value	18,441	59,176
Less than 12 months, Unrealized Loss	33	109
More than 12 months, Fair Value	8,647	3,401
More than 12 months, Unrealized Loss	20	96
Debt Securities [Member]
Investments held in an unrealized loss position
Fair Value	787,037	656,641
Unrealized Loss	21,628	19,336
Less than 12 months, Fair Value	699,655	476,015
Less than 12 months, Unrealized Loss	16,179	14,149
More than 12 months, Fair Value	87,382	180,626
More than 12 months, Unrealized Loss	$ 5,449	$ 5,187

Investments (Net Investment Inc

Investments (Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net Investment Income
Investment fees and expenses	$ (1,396)	$ (2,215)	$ (3,026)	$ (4,649)
Net investment income	27,955	30,225	55,258	59,957
Fixed maturities [Member]
Net Investment Income
Investment Income	25,025	28,919	49,984	56,960
Equities [Member]
Net Investment Income
Investment Income	3,456	2,551	6,468	4,818
Short-term investments and Other invested assets [Member]
Net Investment Income
Investment Income	396	518	902	1,930
BOLI [Member]
Net Investment Income
Investment Income	$ 474	$ 452	$ 930	$ 898

Investments (Net Realized Inves

Investments (Net Realized Investment Gains (Losses)) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment (OTTI) losses	$ (1,209)	$ 0	$ (4,480)	$ (50)
Corporate debt	348	0	1,789	0
Net impairments recognized in earnings	(861)	0	(2,691)	(50)
Gross realized gains, available-for-sale securities	3,627	2,170	7,640	2,975
Gross realized (losses), available-for-sale securities	(810)	(265)	(2,065)	(319)
Net realized gains (losses), trading securities	9,525	4,819	12,192	18,602
Net realized gains (losses), Other investments	602	68	718	266
Change in unrealized holding gains (losses), trading securities	(15,751)	5,443	(14,893)	(7,503)
Change in unrealized holding gains (losses), convertible securities, carried at fair value	(968)	811	(698)	1,819
Other	808	0	808	0
Total net realized investment gains (losses)	(3,828)	13,046	1,011	15,790
US States and Political Subdivisions Debt Securities [Member]
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment (OTTI) losses	0	0	0	(50)
Corporate debt [Member]
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment (OTTI) losses	(1,209)	0	(4,480)	0
Corporate debt	$ 348	$ 0	$ 1,789	$ 0

Investments (Credit Losses Reco

Investments (Credit Losses Recorded in Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Cumulative credit losses recorded in earnings related to impaired debt securities
Accumulated credit losses related to impaired debt securities, Beginning Balance	$ 2,062	$ 83	$ 232	$ 83
No OTTI has been previously recognized	0	0	1,830	0
OTTI has been previously recognized	861	0	861	0
Securities sold during the period (realized)	(293)	0	(293)	0
Accumulated credit losses related to impaired debt securities, Ending Balance	$ 2,630	$ 83	$ 2,630	$ 83

Investments (Sales and Purchase

Investments (Sales and Purchases of Available-for-Sale Securities) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Information regarding sales and purchases of available-for-sale securities
Proceeds from sales (exclusive of maturities and paydowns)	$ 95,100	$ 105,700	$ 301,000	$ 122,500
Purchases	$ 160,500	$ 235,100	$ 375,552	$ 365,421

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income taxes receivable	$ 7.3	$ 1.1
Unrecognized tax benefits	$ 0.7	$ 0.6

Deferred Policy Acquisition C46

Deferred Policy Acquisition Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Insurance [Abstract]
Amortization of deferred policy acquisition costs	$ 19.9	$ 21.4	$ 38.9	$ 41.2

Reserve for Losses and Loss A47

Reserve for Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Summary of reserve for losses and loss adjustment expenses
Minimum period for claims resolution			5 years
Net losses:
Favorable development of reserves established in prior years, net	$ 35.1	$ 42.2	$ 68.6	$ 90.4
Liability for unpaid claims and claims adjustment expense incurred claims prior years accident years	2008 through 2012	2007 through 2011	2008 through 2012	2007 through 2011

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details) - Jun. 30, 2015 $ in Millions	USD ($)	GBP (£)
Non-Public Investment Entities [Member]
Other Commitment, Fiscal Year Maturity [Abstract]
Commitments Total	$ 143.4
Commitments due 2015	55
Commitments due 2016 and 2017	87
Commitments due 2018 and 2019	0.7
Commitments due thereafter	0.7
Qualified Affordable Housing Project [Member]
Other Commitment, Fiscal Year Maturity [Abstract]
Commitments Total	13.3
Commitments due 2015	11.9
Commitments due 2016 and 2017	0.5
Commitments due 2018 and 2019	0.3
Commitments due thereafter	0.6
Lloyds Syndicate [Member]
Other Commitment, Fiscal Year Maturity [Abstract]
Required FAL Deposit	$ 89.5
Current lending capacity under revolving credit agreement | £		£ 10,000,000
Interest rate on revolving credit agreement	8.50%	8.50%
Unused commitments to extend credit | £		£ 2,000,000
Remaining borrowing capacity	$ 3.1

Long-term Debt (Details)

Long-term Debt (Details) - USD ($)	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Outstanding long-term debt
Long-term debt	$ 350,000,000	$ 250,000,000
Senior Notes [Member] | Senior notes due 2023 [Member]
Outstanding long-term debt
Long-term debt	$ 250,000,000	250,000,000
Senior notes due 2023, unsecured, interest at 5.3% annually	5.30%
Line of Credit [Member] | Revolving Credit Facility [Member]
Outstanding long-term debt
Long-term debt	$ 100,000,000	$ 0
Senior notes due 2023, unsecured, interest at 5.3% annually	0.77%
Maximum outstanding borrowings under revolving credit agreement	$ 200,000,000
Accordion feature	50,000,000
Minimum net worth	$ 1,340,800,000
Minimum [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Outstanding long-term debt
Commitment fee percentage	0.125%
Basis spread on variable rate	0.00%
Maximum [Member] | Line of Credit [Member] | Revolving Credit Facility [Member]
Outstanding long-term debt
Commitment fee percentage	0.25%
Basis spread on variable rate	1.63%

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) - USD ($)	1 Months Ended		3 Months Ended				6 Months Ended
	Feb. 28, 2015	Feb. 28, 2014	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized common stock (in shares)			100,000,000				100,000,000		100,000,000
Authorized preferred stock (in shares)			50,000,000				50,000,000		50,000,000
Quarterly dividend declared, per share (USD per share)			$ 0.31	$ 0.31	$ 0.3	$ 0.30	$ 0.62	$ 0.6
Dividend declared			$ 16,700,000		$ 17,600,000		$ 33,900,000	$ 35,500,000
Total authorizations which remain available for use			158,200,000				158,200,000
Authorized repurchase amount			100,000,000				$ 100,000,000
Common shares acquired (in shares)							2,700,000
Cost of common shares reacquired							$ 123,301,000	122,281,000
Share-based compensation			2,300,000		2,400,000		4,966,000	5,641,000
Tax benefits from share-based compensation expense			800,000		$ 800,000		1,700,000	$ 2,000,000
Bonus compensation shares issued (in shares)	28,000
Other comprehensive income (loss), defined benefit plans, net of tax							(1,000,000)
Non-credit loss, net of tax			800,000				800,000		$ 500,000
Unrecognized changes in defined benefit plan liabilities			$ (1,000,000)				$ (1,000,000)
Tax rate used to compute the tax effect of amounts reclassified out of OCI			35.00%		35.00%		35.00%	35.00%
Restricted Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards in period (in shares)	92,000
Fair value of each unit awarded (USD per share)	$ 42.73
Award vesting period	3 years
Shares issued in period for share-based compensation (in shares)	28,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards in period (in shares)	106,500
Fair value of each unit awarded (USD per share)	$ 42.73
Award vesting period	3 years
Shares issued in period for share-based compensation (in shares)	116,000
Minimum [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award payout rate	104.00%	75.00%
Maximum [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award payout rate	125.00%	125.00%

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Reclassifications from AOCI to net income, available-for-sale securities:
Tax effect (at 35%)	$ (7,854)	$ (16,125)	$ (15,561)	$ (30,803)
Net income	$ 33,158	$ 49,942	$ 70,972	$ 96,673
Tax rate used to compute the tax effect of OCI components	35.00%	35.00%	35.00%	35.00%
Deferred tax expense (benefit) included in OCI	$ (13,481)	$ 5,932	$ (9,349)	$ 11,634
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassifications from AOCI to net income, available-for-sale securities:
Tax effect (at 35%)	(685)	(667)	(1,009)	(912)
Net income	1,271	1,238	1,875	1,694
Reclassification out of Accumulated Other Comprehensive Income [Member] | Realized investment gains (losses) [Member]
Reclassifications from AOCI to net income, available-for-sale securities:
Reclassification from AOCI to income	$ 1,956	$ 1,905	$ 2,884	$ 2,606

Variable Interest Entities (Det

Variable Interest Entities (Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Other Investments [Member]
Variable Interest Entity [Line Items]
VIE interests carrying value	$ 36	$ 33.3
VIE interest maximum loss exposure	36	33.3
Investment in unconsolidated subsidiaries [Member]
Variable Interest Entity [Line Items]
VIE interests carrying value	72.9	65
VIE interest maximum loss exposure	$ 72.9	$ 65

Segment Information (Narrative)

Segment Information (Narrative) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015USD ($)	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)Segment	Jun. 30, 2014USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | Segment			4
Workers Compensation [Member]
Segment Reporting Information [Line Items]
Worker's compensation SPC percentage ceded	100.00%		100.00%
Lloyds Syndicate [Member]
Segment Reporting Information [Line Items]
Proportion of Capital Provided to support Lloyd's Syndicate 1729	58.00%		58.00%
Specialty Property and Casualty [Member]
Segment Reporting Information [Line Items]
Premiums Ceded To Lloyd's Syndicate Segment	$ 3.6	$ 0.5	$ 7	$ 0.5

Segment Information (Financial

Segment Information (Financial Data by Segment) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Net premiums earned		$ 175,293	$ 176,303	$ 347,192	$ 348,032
Net investment income		27,955	30,225	55,258	59,957
Equity in earnings (loss) of unconsolidated subsidiaries		2,420	719	4,041	2,470
Net realized gains (losses)		(3,828)	13,046	1,011	15,790
Other income		1,576	2,154	3,745	4,249
Net losses and loss adjustment expenses		(103,939)	(98,913)	(209,078)	(188,421)
Underwriting, policy acquisition and operating expenses	[1]	(53,525)	(52,157)	(104,881)	(104,672)
Segregated portfolio cells dividend expense		(1,230)	(1,789)	(3,414)	(2,838)
Interest expense		(3,710)	(3,521)	(7,341)	(7,091)
Income tax benefit (expense)		(7,854)	(16,125)	(15,561)	(30,803)
Segment operating results		33,158	49,942	70,972	96,673
Depreciation and amortization		11,583	12,387	23,668	23,974
Operating Segments [Member] | Specialty P&C [Member]
Segment Reporting Information [Line Items]
Net premiums earned		112,608	124,677	227,472	250,911
Other income		1,376	1,533	2,874	3,098
Net losses and loss adjustment expenses		(64,054)	(66,664)	(133,084)	(127,624)
Underwriting, policy acquisition and operating expenses	[1]	(26,645)	(33,510)	(53,806)	(67,230)
Segment operating results		23,285	26,036	43,456	59,155
Depreciation and amortization		1,980	2,297	4,143	4,374
Operating Segments [Member] | Workers Compensation [Member]
Segment Reporting Information [Line Items]
Net premiums earned		53,581	48,674	104,858	94,169
Other income		163	184	300	323
Net losses and loss adjustment expenses		(34,310)	(30,380)	(66,412)	(58,928)
Underwriting, policy acquisition and operating expenses	[1]	(15,831)	(15,007)	(31,189)	(30,595)
Segregated portfolio cells dividend expense		(1,230)	(1,789)	(3,414)	(2,838)
Segment operating results		2,373	1,682	4,143	2,131
Depreciation and amortization		1,429	1,300	2,869	2,782
Operating Segments [Member] | Lloyds Syndicate [Member]
Segment Reporting Information [Line Items]
Net premiums earned		9,104	2,952	14,862	2,952
Net investment income		189	109	393	124
Net realized gains (losses)		4		15
Other income		3		492
Net losses and loss adjustment expenses		(5,575)	(1,869)	(9,582)	(1,869)
Underwriting, policy acquisition and operating expenses	[1]	(3,964)	(2,538)	(7,544)	(3,414)
Income tax benefit (expense)		(620)		(620)
Segment operating results		(859)	(1,346)	(1,984)	(2,207)
Depreciation and amortization		106	172	236	172
Operating Segments [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Net premiums earned		0	0		0
Net investment income		27,766	30,116	54,865	59,833
Equity in earnings (loss) of unconsolidated subsidiaries		2,420	719	4,041	2,470
Net realized gains (losses)		(3,832)	13,046	996	15,790
Other income		111	523	268	1,033
Underwriting, policy acquisition and operating expenses	[1]	(7,162)	(1,188)	(12,531)	(3,638)
Interest expense		(3,710)	(3,521)	(7,341)	(7,091)
Income tax benefit (expense)		(7,234)	(16,125)	(14,941)	(30,803)
Segment operating results		8,359	23,570	25,357	37,594
Depreciation and amortization		8,068	8,618	16,420	16,646
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net premiums earned		0	0	0	0
Other income		(77)	(86)	(189)	(205)
Underwriting, policy acquisition and operating expenses	[1]	77	86	189	205
Segment operating results		0	0	0	0
Depreciation and amortization		$ 0	$ 0	$ 0	$ 0
[1]	Beginning with the first quarter of 2015, the operating subsidiaries within the Specialty P&C and Workers' Compensation segments were charged a management fee by the Corporate segment for various management services provided to the subsidiary. Under the new arrangement, the expenses associated with such services are reported as expenses of the Corporate segment, and the management fees charged are reported as an offset to Corporate operating expenses. Prior to 2015, a substantial portion of expenses associated with corporate services were directly allocated to the insurance subsidiaries included in the Specialty P&C segment.

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2015		Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Segment Reporting Information [Line Items]
Net premiums earned	$ 175,293		$ 176,303	$ 347,192		$ 348,032
Operating Segments [Member] | Specialty P&C [Member]
Segment Reporting Information [Line Items]
Ceded premiums earned	(18,761)	[1]	(11,507)	(36,282)	[1]	(22,458)	[1]
Net premiums earned	112,608		124,677	227,472		250,911
Operating Segments [Member] | Workers Compensation [Member]
Segment Reporting Information [Line Items]
Ceded premiums earned	(6,290)		(4,457)	(12,746)		(9,097)
Net premiums earned	53,581		48,674	104,858		94,169
Operating Segments [Member] | Lloyds Syndicate [Member]
Segment Reporting Information [Line Items]
Ceded premiums earned	(1,219)		(72)	(1,998)		(72)
Net premiums earned	9,104		2,952	14,862		2,952
Operating Segments [Member] | Healthcare professional liability [Member] | Specialty P&C [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	115,057		119,706	230,887		240,556
Operating Segments [Member] | Legal professional liability [Member] | Specialty P&C [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	7,239		7,015	14,439		14,002
Operating Segments [Member] | Medical technology and life sciences product liability [Member] | Specialty P&C [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	8,685		9,028	17,657		17,785
Operating Segments [Member] | Other [Member] | Specialty P&C [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	388		435	771		1,026
Operating Segments [Member] | Traditional business [Member] | Workers Compensation [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	43,986		39,905	85,989		77,358
Operating Segments [Member] | Alternative market business [Member] | Workers Compensation [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	15,885		13,226	31,615		25,908
Operating Segments [Member] | Property, Liability and Casualty Insurance Product Line [Member] | Lloyds Syndicate [Member]
Segment Reporting Information [Line Items]
Gross premiums earned	$ 10,323	[1]	$ 3,024	$ 16,860	[1]	$ 3,024	[1]
[1]	Includes premium ceded from the Specialty P&C Segment to the Lloyd's Syndicate Segment of $3.6 million and $7.0 million for the three and six months ended June 30, 2015 and $0.5 million for both the three and six months ended June 30, 2014.