ProAssurance (PRA) 10-Q 9 May 22 2022 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2022	May 04, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity File Number	0-16533
Entity Registrant Name	ProAssurance Corporation
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	63-1261433
Entity Address, Address Line One	100 Brookwood Place,
Entity Address, City or Town	Birmingham,
Entity Address, State or Province	AL
Entity Address, Postal Zip Code	35209
City Area Code	(205)
Local Phone Number	877-4400
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	PRA
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		54,047,919
Entity Central Index Key	0001127703
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Investments
Fixed maturities, available-for-sale, at fair value (amortized cost, $3,861,574 and $3,814,847, respectively; allowance for expected credit losses, none as of each respective period end)	$ 3,700,821	$ 3,833,722
Fixed maturities, trading, at fair value (cost, $49,986 and $43,914, respectively)	49,421	43,670
Equity investments, at fair value (cost, $211,962 and $211,356, respectively)	203,925	214,807
Short-term investments	233,345	216,987
Business owned life insurance	80,879	81,767
Investment in unconsolidated subsidiaries	321,402	335,576
Other investments (at fair value, $100,678 and $98,611, respectively, otherwise at cost or amortized cost)	103,876	101,794
Total Investments	4,693,669	4,828,323
Cash and cash equivalents	72,101	143,602
Premiums receivable (allowance for expected credit losses, $7,711 as of March 31, 2022 and $7,436 as of December 31, 2021)	260,929	241,095
Receivable from reinsurers on paid losses and loss adjustment expenses	14,310	14,599
Receivable from reinsurers on unpaid losses and loss adjustment expenses	464,780	451,741
Prepaid reinsurance premiums	32,198	24,571
Deferred policy acquisition costs	65,491	58,940
Deferred tax asset, net	157,214	117,613
Real estate, net	30,117	30,342
Operating lease ROU assets	17,989	19,595
Intangible assets, net	71,717	73,336
Goodwill	49,610	49,610
Other assets	128,473	138,110
Total Assets	6,058,598	6,191,477
Policy liabilities and accruals
Reserve for losses and loss adjustment expenses	3,603,246	3,579,940
Unearned premiums	486,693	433,961
Reinsurance premiums payable	24,891	22,627
Total Policy Liabilities and Accruals	4,114,830	4,036,528
Operating lease liabilities	19,190	20,844
Other liabilities	217,280	280,732
Debt less unamortized debt issuance costs	425,530	424,986
Total Liabilities	4,776,830	4,763,090
Shareholders' Equity
Common shares (par value $0.01 per share, 100,000,000 shares authorized, 63,371,520 and 63,308,741 shares issued, respectively)	634	633
Additional paid-in capital	393,433	392,941
Accumulated other comprehensive income (loss) (net of deferred tax expense (benefit) of ($33,755) and $4,423, respectively)	(124,566)	16,284
Retained earnings	1,428,229	1,434,491
Treasury shares, at cost (9,325,180 shares as of each respective period end)	(415,962)	(415,962)
Total Shareholders' Equity	1,281,768	1,428,387
Total Liabilities and Shareholders' Equity	$ 6,058,598	$ 6,191,477

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Available for sale securities, amortized cost	$ 3,861,574,000	$ 3,814,847,000
Allowance for expected credit losses	0
Trading securities, cost	49,986,000	43,914,000
Equity investments at fair value, cost	211,962,000	211,356,000
Premium receivable, allowance for credit loss	7,711,000	7,436,000
Other investments, portion carried at fair value	$ 100,678,000	$ 98,611,000
Common shares, par value (in usd per share)	$ 0.01	$ 0.01
Common shares, shares authorized (in shares)	100,000,000	100,000,000
Common shares, shares issued (in shares)	63,371,520	63,308,741
Deferred tax expense (benefit) on accumulated other comprehensive income (loss)	$ (33,755,000)	$ 4,423,000
Treasury shares, number of shares (in shares)	9,325,180	9,325,180

Condensed Consolidated Statemen

Condensed Consolidated Statements of Changes in Capital (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Increase (Decrease) in Stockholders' Equity:
Beginning balance	$ 1,428,387	$ 1,349,210
Common shares issued for compensation and effect of shares reissued to stock purchase plan	7	8
Share-based compensation	1,342	1,024
Net effect of restricted and performance shares issued	(856)	(257)
Dividends to shareholders	(2,702)	(2,699)
Other comprehensive income (loss)	(140,850)	(33,705)
Net income (loss)	(3,560)	7,735
Ending balance	1,281,768	1,321,316
Common Stock
Increase (Decrease) in Stockholders' Equity:
Beginning balance	633	632
Net effect of restricted and performance shares issued	1	1
Ending balance	634	633
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity:
Beginning balance	392,941	388,150
Common shares issued for compensation and effect of shares reissued to stock purchase plan	7	8
Share-based compensation	1,342	1,024
Net effect of restricted and performance shares issued	(857)	(258)
Ending balance	393,433	388,924
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity:
Beginning balance	16,284	75,227
Other comprehensive income (loss)	(140,850)	(33,705)
Ending balance	(124,566)	41,522
Retained Earnings
Increase (Decrease) in Stockholders' Equity:
Beginning balance	1,434,491	1,301,163
Dividends to shareholders	(2,702)	(2,699)
Net income (loss)	(3,560)	7,735
Ending balance	1,428,229	1,306,199
Treasury Stock
Increase (Decrease) in Stockholders' Equity:
Beginning balance	(415,962)	(415,962)
Ending balance	$ (415,962)	$ (415,962)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Income and Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenues
Net premiums earned	$ 265,711	$ 187,358
Net investment income	20,443	15,017
Equity in earnings (loss) of unconsolidated subsidiaries	7,620	6,788
Net investment gains (losses):
Other net investment gains (losses)	(13,506)	8,849
Total net investment gains (losses)	(13,506)	8,849
Other income	2,804	2,005
Total revenues	283,072	220,017
Expenses
Net losses and loss adjustment expenses	209,423	149,785
Underwriting, policy acquisition and operating expenses:
Operating expense	38,810	31,522
DPAC amortization	32,966	24,929
SPC U.S. federal income tax expense	642	356
SPC dividend expense (income)	2,367	1,742
Interest expense	4,441	3,212
Total expenses	288,649	211,546
Income (loss) before income taxes	(5,577)	8,471
Provision for income taxes:
Current expense (benefit)	(607)	3,008
Deferred expense (benefit)	(1,410)	(2,272)
Total income tax expense (benefit)	(2,017)	736
Net income (loss)	(3,560)	7,735
Other comprehensive income (loss), after tax, net of reclassification adjustments	(140,850)	(33,705)
Comprehensive income (loss)	$ (144,410)	$ (25,970)
Earnings (loss) per share:
Basic (in usd per share)	$ (0.07)	$ 0.14
Diluted (in usd per share)	$ (0.07)	$ 0.14
Weighted average number of common shares outstanding:
Basic (in shares)	54,012	53,918
Diluted (in shares)	54,143	53,998
Cash dividends declared per common share (in usd per share)	$ 0.05	$ 0.05

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating Activities
Net income (loss)	$ (3,560)	$ 7,735
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization, net of accretion	10,350	6,722
(Increase) decrease in cash surrender value of BOLI	888	915
Net investment (gains) losses	13,506	(8,849)
Share-based compensation	1,343	1,031
Deferred income tax expense (benefit)	(1,410)	(2,272)
Policy acquisition costs, net of amortization (net deferral)	(6,551)	(420)
Equity in (earnings) loss of unconsolidated subsidiaries	(7,620)	(6,788)
Distributed earnings from unconsolidated subsidiaries	14,176	5,658
Other, net	(1,056)	(661)
Change in:
Premiums receivable	(19,834)	(9,165)
Reinsurance related assets and liabilities	(18,113)	(12,290)
Other assets	12,367	13,151
Reserve for losses and loss adjustment expenses	23,306	21,071
Unearned premiums	52,732	13,699
Other liabilities	(56,259)	(837)
Net cash provided (used) by operating activities	14,265	28,700
Purchases of:
Fixed maturities, available-for-sale	(231,557)	(342,197)
Equity investments	(28,129)	(38,232)
Other investments	(12,757)	(33,252)
Investment in unconsolidated subsidiaries	(9,685)	(5,319)
Proceeds from sales or maturities of:
Fixed maturities, available-for-sale	176,820	195,266
Equity investments	27,305	82,048
Other investments	9,205	12,026
Net sales or (purchases) of fixed maturities, trading	(6,119)	3,163
Return of invested capital from unconsolidated subsidiaries	17,302	17,618
Net sales or maturities (purchases) of short-term investments	(16,632)	56,836
Unsettled security transactions, net change	(2,076)	27,025
Purchases of capital assets	(811)	(1,243)
Net cash provided (used) by investing activities	(77,134)	(26,261)
Financing Activities
Repayments of Mortgage Loans	0	(390)
Dividends to shareholders	(2,691)	(2,686)
Capital contribution received from (return of capital to) external segregated portfolio cell participants	(5,085)	(53)
Other	(856)	(257)
Net cash provided (used) by financing activities	(8,632)	(3,386)
Increase (decrease) in cash and cash equivalents	(71,501)	(947)
Cash and cash equivalents at beginning of period	143,602	215,782
Cash and cash equivalents at end of period	72,101	214,835
Significant Non-Cash Transactions
Dividends declared and not yet paid	$ 2,702	$ 2,699

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2022
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, its wholly owned subsidiaries and VIEs in which ProAssurance is the primary beneficiary (ProAssurance, PRA or the Company). See Note 9 for more information on ProAssurance's VIE interests. 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 three months ended March 31, 2022 are not necessarily indicative of the results that may be expected for the year ending December 31, 2022. The accompanying Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and Notes contained in ProAssurance’s December 31, 2021 report on Form 10-K. ProAssurance operates in five reportable segments as follows: Specialty P&C, Workers' Compensation Insurance, Segregated Portfolio Cell Reinsurance, Lloyd's Syndicates and Corporate. For more information on the Company's segment reporting, including the nature of products and services provided and financial information by segment, refer to Note 11. During the first quarter of 2022, ProAssurance revised its estimate of ULAE as a result of substantially integrating NORCAL into the Specialty P&C segment operations. ULAE are costs that cannot be attributed to processing a specific claim and are allocated to net losses and loss adjustment expenses on the Condensed Consolidated Statement of Income and Comprehensive Income. ProAssurance accounted for this change prospectively as a change in accounting estimate. Changes in accounting estimate are reflected prospectively beginning in the period the change in estimate occurs. The change in the Company's estimate of ULAE resulted in an increase of $7.3 million to underwriting, policy acquisition and operating expenses with an offsetting decrease of $7.3 million to net losses and loss adjustment expenses when compared to amounts that would have been estimated as ULAE under the Company's previous methodology. There was no impact on total expenses or net income (loss) in the Company's Condensed Consolidated Statement of Income and Comprehensive Income for the three months ended March 31, 2022 as a result of this change in the estimate. Accounting Policies The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities, revenues and expenses, and disclosures related to these amounts at the date of the financial statements. The Company evaluates these estimates and assumptions on an ongoing basis based on current and historical developments, market conditions, industry trends and other information that the Company believes to be reasonable under the circumstances, including the potential impacts of the COVID-19 pandemic (see "Item 1A, Risk Factors" in ProAssurance's December 31, 2021 report on Form 10-K for additional information). The Company can make no assurance that actual results will conform to its estimates and assumptions; reported results of operations may be materially affected by changes in these estimates and assumptions. The significant accounting policies followed by ProAssurance in making estimates that materially affect financial reporting are summarized in Note 1 of the Notes to Consolidated Financial Statements in ProAssurance’s December 31, 2021 report on Form 10-K. Accounting Changes Adopted ProAssurance has not adopted any accounting changes during the three months ended March 31, 2022 that had a material effect on its results of operations, financial position or cash flows. Accounting Changes Not Yet Adopted ProAssurance is not aware of any accounting changes not yet adopted as of March 31, 2022 that could have a material impact on its results of operations, financial position or cash flows.

Fair Value Measurement

Fair Value Measurement	3 Months Ended
	Mar. 31, 2022
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 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 March 31, 2022 and December 31, 2021 are shown in the following tables. Where applicable, 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. For more information on the valuation methodologies used regarding securities in the Level 2 and Level 3 categories, see Note 3 of the Notes to Consolidated Financial Statements in ProAssurance’s December 31, 2021 report on Form 10-K. March 31, 2022 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 $ — $ 225,676 $ — $ 225,676 U.S. Government-sponsored enterprise obligations — 16,733 — 16,733 State and municipal bonds — 492,291 — 492,291 Corporate debt, multiple observable inputs — 1,816,931 — 1,816,931 Corporate debt, limited observable inputs — — 53,325 53,325 Residential mortgage-backed securities — 417,276 572 417,848 Agency commercial mortgage-backed securities — 12,847 — 12,847 Other commercial mortgage-backed securities — 222,800 582 223,382 Other asset-backed securities — 433,639 8,149 441,788 Fixed maturities, trading — 49,421 — 49,421 Equity investments Financial 12,074 2,289 — 14,363 Utilities/Energy 1,099 — — 1,099 Industrial — — 2,500 2,500 Bond funds 170,338 — — 170,338 All other 15,625 — — 15,625 Short-term investments 210,122 23,223 — 233,345 Other investments 1,789 95,449 3,440 100,678 Other assets — 1,663 — 1,663 Total assets categorized within the fair value hierarchy $ 411,047 $ 3,810,238 $ 68,568 4,289,853 Assets carried at NAV, which approximates fair value and which are not categorized within the fair value hierarchy, reported as a part of: Investment in unconsolidated subsidiaries 267,125 Total assets at fair value $ 4,556,978 Liabilities: Other liabilities $ — $ — $ 24,000 $ 24,000 Total liabilities categorized within the fair value hierarchy $ — $ — $ 24,000 $ 24,000 December 31, 2021 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 $ — $ 238,507 $ — $ 238,507 U.S. Government-sponsored enterprise obligations — 20,234 — 20,234 State and municipal bonds — 519,196 — 519,196 Corporate debt, multiple observable inputs — 1,851,427 — 1,851,427 Corporate debt, limited observable inputs — — 47,129 47,129 Residential mortgage-backed securities — 453,644 297 453,941 Agency commercial mortgage-backed securities — 14,141 — 14,141 Other commercial mortgage-backed securities — 231,483 — 231,483 Other asset-backed securities — 451,459 6,205 457,664 Fixed maturities, trading — 43,670 — 43,670 Equity investments Financial 6,615 855 — 7,470 Industrial — — 2,500 2,500 Bond funds 187,059 — — 187,059 All other 17,778 — — 17,778 Short-term investments 174,944 42,043 — 216,987 Other investments 1,889 95,288 1,434 98,611 Other assets — 649 — 649 Total assets categorized within the fair value hierarchy $ 388,285 $ 3,962,596 $ 57,565 4,408,446 Assets carried at NAV, which approximates fair value and which are not categorized within the fair value hierarchy, reported as a part of: Investment in unconsolidated subsidiaries 270,816 Total assets at fair value $ 4,679,262 Liabilities: Other liabilities $ — $ — $ 24,000 $ 24,000 Total liabilities categorized within the fair value hierarchy $ — $ — $ 24,000 $ 24,000 Level 3 Valuations Other than as described below, see Note 3 of the Notes to Consolidated Financial Statements in ProAssurance’s December 31, 2021 report on Form 10-K for a summary description of the valuation methodologies used regarding securities in the Level 3 category, by security type. Level 3 Valuation Methodologies Residential mortgage-backed, other commercial mortgage-backed securities and 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. 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 March 31, 2022, 100% of the securities were rated and the average rating was A. At December 31, 2021, 100% of the securities were rated and the average rating was BBB+. Quantitative Information Regarding Level 3 Valuations Below is a quantitative information regarding securities in the Level 3 category, by security type: Fair Value at ($ in thousands) March 31, 2022 December 31, 2021 Valuation Technique Unobservable Input Range Assets: Corporate debt, limited observable inputs $53,325 $47,129 Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Residential mortgage-backed securities $572 $297 Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Other commercial mortgage-backed securities $582 $— Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Other asset-backed securities $8,149 $6,205 Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Equity investments $2,500 $2,500 Discounted Cash Flows Comparability Adjustment 0% - 10% (5%) Other investments $3,440 $1,434 Discounted Cash Flows Comparability Adjustment 0% - 10% (5%) Liabilities: Other liabilities $24,000 $24,000 Stochastic Model/Discounted Cash Flows N/A 0% - 10% (8%) 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 present summary information regarding changes in the fair value of assets measured using Level 3 inputs. March 31, 2022 Level 3 Fair Value Measurements - Assets (In thousands) Corporate Debt Asset-backed Securities Equity Investments Other Investments Total Balance, December 31, 2021 $ 47,129 $ 6,502 $ 2,500 $ 1,434 $ 57,565 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income — 1 — — 1 Net investment gains (losses) — — — 110 110 Included in other comprehensive income (993) (260) — — (1,253) Purchases 9,711 5,585 — 1,483 16,779 Sales (1,019) (5) — (116) (1,140) Transfers in 1,000 — — 529 1,529 Transfers out (2,503) (2,520) — — (5,023) Balance, March 31, 2022 $ 53,325 $ 9,303 $ 2,500 $ 3,440 $ 68,568 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ 64 $ 64 March 31, 2021 Level 3 Fair Value Measurements – Assets (In thousands) Corporate Debt Asset-backed Securities Other Investments Total Balance, December 31, 2020 $ 3,265 $ 8,693 $ — $ 11,958 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income 1 (2) — (1) Net investment gains (losses) — (11) — (11) Included in other comprehensive income 20 (179) — (159) Purchases 4,875 7,357 — 12,232 Sales (17) (304) — (321) Transfers in 858 — 2,152 3,010 Transfers out (1,233) (6,241) — (7,474) Balance, March 31, 2021 $ 7,769 $ 9,313 $ 2,152 $ 19,234 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ — Fair Value Measurements - Level 3 Liabilities There was no change in the fair value of the contingent consideration from the date of the NORCAL acquisition on May 5, 2021 to December 31, 2021 or March 31, 2022. Transfers Transfers shown in the preceding Level 3 tables were as of the end of the period in which the transfer occurred. All transfers were to or from Level 2. All transfers in and out of Level 3 during the three months ended March 31, 2022 and 2021 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 At March 31, 2022 and December 31, 2021, certain LPs/LLCs and investment funds measure fund assets at fair value on a recurring basis and provide a NAV for ProAssurance's interest. The carrying value of these interests is based on the NAV provided and was considered to approximate the fair value of the interests. For investment in unconsolidated subsidiaries, ProAssurance recognizes any changes in the NAV of its interests in equity in earnings (loss) of unconsolidated subsidiaries during the period of change. In accordance with GAAP, the fair value of these investments was not classified within the fair value hierarchy. The amount of ProAssurance's unfunded commitments related to these investments as of March 31, 2022 and fair values of these investments as of March 31, 2022 and December 31, 2021 were as follows: Unfunded Fair Value (In thousands) March 31, March 31, December 31, Investment in unconsolidated subsidiaries: Private debt funds (1) $4,515 $ 17,674 $ 18,465 Long/short equity funds (2) None 209 655 Non-public equity funds (3) $55,591 158,286 160,219 Credit funds (4) $51,868 45,174 47,300 Strategy focused funds (5) $28,244 45,782 44,177 Total investments carried at NAV $ 267,125 $ 270,816 Below is additional information regarding each of the investments listed in the table above as of March 31, 2022. (1) This investment is 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, while 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 three (2) This investment holds primarily long and short North American equities and targets absolute returns using strategies designed to take advantage of market opportunities. Redemptions are permitted; however, 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. (3) This investment is comprised of interests in multiple unrelated LP funds, each structured to provide capital appreciation through diversified investments in private equity, which can include investments in buyout, venture capital, debt including senior, second lien and mezzanine, distressed debt, collateralized loan obligations and other private equity-oriented LPs. Two of the LPs allow redemption by terms set forth in the LP agreements; 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 ten years. (4) This investment is comprised of multiple unrelated LP funds. Two funds seek to obtain superior risk-adjusted absolute returns through a diversified portfolio of debt securities, including bonds, loans and other asset-backed instruments. The remaining funds focus on private middle market company mezzanine and senior secured loans, opportunities across the credit spectrum, mortgage backed-loans, as well as various types of loan-backed investments. One fund allows redemptions at any quarter-end with prior notice requirements of 180 days, while two other funds allow for redemptions with consent of the General Partner. The remaining funds do not allow redemptions. For the funds that do not allow redemptions, income and capital are to be periodically distributed at the discretion of the LP over time frames throughout the remaining life of the funds. (5) This investment is comprised of multiple unrelated LPs/LLCs funds. One fund is an LLC focused on investing in North American consumer products companies, comprised of equity and equity-related securities, as well as debt instruments. A second fund is focused on aircraft investments, along with components and assets related to aircrafts. For both funds, redemptions are not permitted. Another fund is an LP focused on North American energy infrastructure assets that allows redemption with consent of the General Partner. The remaining funds are real estate focused LPs, one of which allows for redemption with prior notice. ProAssurance may not sell, transfer or assign its interest in any of the above LPs/LLCs without special consent from the LPs/LLCs. Nonrecurring Fair Value Measurement ProAssurance did not have any assets or liabilities that were measured at fair value on a nonrecurring basis at March 31, 2022 or December 31, 2021. Financial Instruments - Methodologies Other Than Fair Value The following table provides the estimated fair value of the Company's financial instruments that, in accordance with GAAP for the type of investment, are measured using a methodology other than fair value. Fair values provided primarily fall within the Level 3 fair value category. March 31, 2022 December 31, 2021 (In thousands) Carrying Fair Carrying Fair Financial assets: BOLI $ 80,879 $ 80,879 $ 81,767 $ 81,767 Other investments $ 3,198 $ 3,198 $ 3,183 $ 3,183 Other assets $ 33,029 $ 33,016 $ 40,581 $ 40,583 Financial liabilities: Senior notes due 2023* $ 250,000 $ 255,913 $ 250,000 $ 264,000 Contribution Certificates $ 176,351 $ 161,533 $ 175,900 $ 179,892 Other liabilities $ 31,446 $ 31,446 $ 52,332 $ 52,332 * Carrying value excludes unamortized debt issuance costs. 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 FHLB common stock carried at cost and an annuity investment carried at amortized cost. Three of ProAssurance's insurance subsidiaries are members of an FHLB. The estimated fair value of the FHLB common stock was based on the amount the subsidiaries would receive if their memberships were canceled, as the memberships 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. The fair value of the funded deferred compensation assets was based upon quoted market prices, which is categorized as a Level 1 valuation, and had a fair value of $32.0 million and $39.5 million at March 31, 2022 and December 31, 2021, respectively. The fair value of the funded deferred compensation assets at December 31, 2021 included assets from a rabbi trust plan acquired in the NORCAL acquisition that was terminated during the three months ended March 31, 2022. The rabbi trust assets consisted entirely of cash equivalents and mutual funds and had a total fair value of $5.2 million as of December 31, 2021 (see Note 2 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K for additional information on the NORCAL acquisition). Other assets also included an unsecured note receivable. The fair value of the note receivable was based on the present value of expected cash flows from the note receivable, discounted at market rates on the valuation date for receivables with similar credit standings and similar payment structures. Other liabilities primarily consisted of liabilities associated with funded deferred compensation agreements. The reported balance is determined based on the amount of elective deferrals and employer contributions adjusted for periodic changes in the fair value of the participant balances based on the performance of the funds selected by the participants and had a fair value of $31.4 million and $52.3 million at March 31, 2022 and December 31, 2021, respectively. The fair value of the funded deferred compensation liabilities at December 31, 2021 included liabilities from deferred compensation arrangements assumed in the NORCAL acquisition that were terminated during the three months ended March 31, 2022 using the associated rabbit trust assets and cash; the termination of these deferred compensation arrangements did not result in a gain or loss during the current period. The funded deferred compensation liabilities had a total fair value of $18.4 million as of December 31, 2021 (see Note 2 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K for additional information). The fair value of the debt, excluding the Contribution Certificates, 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. The fair value of the Contribution Certificates was estimated based on a binomial option pricing model. The Contribution Certificates is a portion of the purchase consideration for the NORCAL acquisition and are issued to certain NORCAL policyholders in the conversion, and those instruments are an obligation of NORCAL Insurance Company, the successor of NORCAL Mutual Insurance Company (see Note 2 and Note 13 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K for further discussion of the terms of the Contribution Certificates).

Investments

Investments	3 Months Ended
	Mar. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Investments	Investments Available-for-sale fixed maturities at March 31, 2022 and December 31, 2021 included the following: March 31, 2022 (In thousands) Amortized Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Fixed maturities, available-for-sale U.S. Treasury obligations $ 237,899 $ 240 $ 12,463 $ 225,676 U.S. Government-sponsored enterprise obligations 17,650 15 932 16,733 State and municipal bonds 511,863 1,368 20,940 492,291 Corporate debt 1,955,390 4,593 89,727 1,870,256 Residential mortgage-backed securities 441,565 2,142 25,859 417,848 Agency commercial mortgage-backed securities 13,231 46 430 12,847 Other commercial mortgage-backed securities 232,924 471 10,013 223,382 Other asset-backed securities 451,052 2,065 11,329 441,788 $ 3,861,574 $ 10,940 $ 171,693 $ 3,700,821 December 31, 2021 (In thousands) Amortized Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Fixed maturities, available-for-sale U.S. Treasury obligations $ 239,765 $ 1,166 $ 2,424 $ 238,507 U.S. Government-sponsored enterprise obligations 20,467 29 262 20,234 State and municipal bonds 511,750 9,620 2,174 519,196 Corporate debt 1,884,455 29,050 14,949 1,898,556 Residential mortgage-backed securities 455,438 4,254 5,751 453,941 Agency commercial mortgage-backed securities 13,909 294 62 14,141 Other commercial mortgage-backed securities 231,226 2,530 2,273 231,483 Other asset-backed securities 457,837 2,747 2,920 457,664 $ 3,814,847 $ 49,690 $ 30,815 $ 3,833,722 The recorded cost basis and estimated fair value of available-for-sale fixed maturities at March 31, 2022, 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 $ 237,899 $ 21,181 $ 128,387 $ 74,586 $ 1,522 $ 225,676 U.S. Government-sponsored enterprise obligations 17,650 1,798 11,029 3,774 132 16,733 State and municipal bonds 511,863 22,193 159,219 188,721 122,158 492,291 Corporate debt 1,955,390 141,092 848,525 774,223 106,416 1,870,256 Residential mortgage-backed securities 441,565 417,848 Agency commercial mortgage-backed securities 13,231 12,847 Other commercial mortgage-backed securities 232,924 223,382 Other asset-backed securities 451,052 441,788 $ 3,861,574 $ 3,700,821 Excluding obligations of the U.S. Government, U.S. Government-sponsored enterprises and a U.S. Government obligations money market fund, no investment in any entity or its affiliates exceeded 10% of shareholders’ equity at March 31, 2022. Cash and securities with a carrying value of $54.5 million at March 31, 2022 were on deposit with various state insurance departments to meet regulatory requirements. As a member of Lloyd's, ProAssurance is required to maintain capital at Lloyd's, referred to as FAL, to support underwriting by Syndicate 1729. At March 31, 2022, ProAssurance's FAL investments were comprised of available-for-sale fixed maturities with a fair value of $36.9 million and cash and cash equivalents of $0.1 million on deposit with Lloyd's in order to satisfy these FAL requirements. Investments Held in a Loss Position The following tables provide summarized information with respect to investments held in an unrealized loss position at March 31, 2022 and December 31, 2021, including the length of time the investment had been held in a continuous unrealized loss position. March 31, 2022 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 $ 208,608 $ 12,463 $ 195,658 $ 11,629 $ 12,950 $ 834 U.S. Government-sponsored enterprise obligations 16,601 932 12,835 599 3,766 333 State and municipal bonds 372,603 20,940 357,967 19,551 14,636 1,389 Corporate debt 1,437,296 89,727 1,292,183 75,597 145,113 14,130 Residential mortgage-backed securities 367,247 25,859 316,182 20,314 51,065 5,545 Agency commercial mortgage-backed securities 9,835 430 9,695 416 140 14 Other commercial mortgage-backed securities 204,736 10,013 194,654 9,310 10,082 703 Other asset-backed securities 375,684 11,329 360,024 10,477 15,660 852 $ 2,992,610 $ 171,693 $ 2,739,198 $ 147,893 $ 253,412 $ 23,800 December 31, 2021 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 $ 190,054 $ 2,424 $ 181,689 $ 2,206 $ 8,365 $ 218 U.S. Government-sponsored enterprise obligations 16,287 262 16,287 262 — — State and municipal bonds 175,442 2,174 171,930 2,039 3,512 135 Corporate debt 945,196 14,949 866,731 11,828 78,465 3,121 Residential mortgage-backed securities 326,248 5,751 290,019 4,320 36,229 1,431 Agency commercial mortgage-backed securities 4,529 62 4,355 54 174 8 Other commercial mortgage-backed securities 151,827 2,273 145,467 1,884 6,360 389 Other asset-backed securities 278,915 2,920 271,463 2,796 7,452 124 $ 2,088,498 $ 30,815 $ 1,947,941 $ 25,389 $ 140,557 $ 5,426 As of March 31, 2022, excluding U.S. Government or U.S. Government-sponsored enterprise obligations, there were 2,504 debt securities (64.6% of all available-for-sale fixed maturity securities held) in an unrealized loss position representing 1,288 issuers. The greatest and second greatest unrealized loss positions among those securities were approximately $2.3 million and $2.0 million, respectively. The securities were evaluated for impairment as of March 31, 2022. As of December 31, 2021, excluding U.S. Government or U.S. Government-sponsored enterprise obligations, there were 1,766 debt securities (45.8% of all available-for-sale fixed maturity securities held) in an unrealized loss position representing 998 issuers. The greatest and second greatest unrealized loss positions among those securities were each approximately $0.4 million. The securities were evaluated for impairment as of December 31, 2021. Each quarter, ProAssurance performs a detailed analysis for the purpose of assessing whether any of the securities it holds in an unrealized loss position has suffered an impairment due to credit or non-credit factors. A detailed discussion of the factors considered in the assessment is included in Note 1 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K. Fixed maturity securities held in an unrealized loss position at March 31, 2022, excluding asset-backed securities, have paid all scheduled contractual payments and are expected to continue. Expected future cash flows of asset-backed securities, excluding those issued by GNMA, FNMA and FHLMC, held in an unrealized loss position were estimated as part of the March 31, 2022 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. There was no allowance for expected credit losses for the three months ended March 31, 2022. The following table presents a roll forward of the allowance for expected credit losses on available-for-sale fixed maturities for the three months ended March 31, 2021. Three Months Ended March 31, 2021 (In thousands) Corporate Debt Total Balance, at December 31, 2020 $ 552 $ 552 Reductions related to: Securities sold during the period (552) (552) Balance, at March 31, 2021 $ — $ — Other information regarding sales and purchases of fixed maturity available-for-sale securities is as follows: Three Months Ended March 31 (In millions) 2022 2021 Proceeds from sales (exclusive of maturities and paydowns) $ 63.5 $ 61.9 Purchases $ 231.6 $ 342.2 Equity Investments ProAssurance's equity investments are carried at fair value with changes in fair value recognized in income as a component of net investment gains (losses) during the period of change. Equity investments on the Condensed Consolidated Balance Sheets as of March 31, 2022 and December 31, 2021 primarily included bond funds and, to a lesser degree, stocks and investment funds. Short-term Investments ProAssurance's short-term investments, which have a maturity at purchase of one year or less, are primarily comprised of investments in U.S. treasury obligations, commercial paper and money market funds. Short-term investments are carried at fair value which approximates the cost of the securities due to their short-term nature. BOLI ProAssurance holds BOLI policies that are carried at the current cash surrender value of the policies (original cost $42 million), which includes the BOLI policies acquired from NORCAL (original cost $10 million). All insured individuals were members of ProAssurance or NORCAL management 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 beneficiary of these policies. Net Investment Income Net investment income (loss) by investment category was as follows: Three Months Ended (In thousands) 2022 2021 Fixed maturities $ 21,544 $ 15,692 Equities 701 694 Short-term investments, including Other 426 273 BOLI (47) 444 Investment fees and expenses (2,181) (2,086) Net investment income $ 20,443 $ 15,017 Investment in Unconsolidated Subsidiaries ProAssurance's investment in unconsolidated subsidiaries were as follows: March 31, 2022 Carrying Value (In thousands) Percentage March 31, December 31, Qualified affordable housing project tax credit partnerships See below $ 10,036 $ 12,424 All other investments, primarily investment fund LPs/LLCs See below 311,366 323,152 $ 321,402 $ 335,576 Qualified affordable housing project 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 ProAssurance's total commitments (both funded and unfunded) to the partnerships, less any amortization. At March 31, 2022, ProAssurance's ownership percentage relative to one of the tax credit partnership interests is almost 100%; this interest had a carrying value of $2.0 million. At December 31, 2021, ProAssurance's ownership percentage relative to two of the tax credit partnership interests was almost 100%; these interests had a carrying value of $3.2 million at December 31, 2021. ProAssurance's ownership percentage relative to the remaining tax credit partnership interests is less than 20%; these interests had a carrying value of $8.0 million at March 31, 2022 and $9.2 million at December 31, 2021. Since ProAssurance has the ability to exert influence over the partnerships but does not control them, all are accounted for using the equity method. See further discussion of the entities in which ProAssurance holds passive interests in Note 9. ProAssurance holds interests in investment fund LPs/LLCs and other equity method investments and LPs/LLCs which are not considered to be investment funds. ProAssurance's ownership percentage relative to four of the LPs/LLCs is greater than 25%, which is expected to be reduced as the funds mature and other investors participate in the funds; these investments had a carrying value of $49.3 million at March 31, 2022 and $49.0 million at December 31, 2021. ProAssurance's ownership percentage relative to the remaining investments and LPs/LLCs is less than 25%; these interests had a carrying value of $262.1 million at March 31, 2022 and $274.2 million at December 31, 2021. ProAssurance does not have the ability to exert control over any of these funds. Equity in Earnings (Loss) of Unconsolidated Subsidiaries Equity in earnings (loss) of unconsolidated subsidiaries included losses from qualified affordable housing project tax credit partnerships and a historic tax credit partnership. Investment results recorded reflect ProAssurance's allocable portion of partnership operating results. Tax credits reduce income tax expense in the period they are utilized. The results recorded and tax credits recognized related to ProAssurance's tax credit partnership investments were as follows: Three Months Ended (In thousands) 2022 2021 Qualified affordable housing project tax credit partnerships Losses recorded $ 2,388 $ 3,368 Tax credits recognized $ 1,205 $ 3,324 Historic tax credit partnership* Losses (gains) recorded $ — $ (182) Tax credits recognized $ — $ 50 *ProAssurance holds a historic tax credit partnership which was fully amortized in 2020. This partnership generated investment returns by providing benefits to fund investors in the form of tax credits, tax deductible project operating losses and positive cash flows. ProAssurance received a distribution associated with this investment during the first quarter of 2021, as a result of positive cash flows from a completed project, which was recognized as an operating gain. The tax credits generated from the Company's tax credit partnership investments of $1.2 million for the three months ended March 31, 2022 were deferred for use in future periods due to the Company's expected consolidated loss calculated on a tax basis. For the three months ended March 31, 2021 the tax credits generated from the Company's tax credit partnership investments of $3.4 million were deferred and are expected to be utilized in future periods. Not included in the table above is $2.0 million of tax credits recaptured from 2019 during the three months ended March 31, 2022 due to the carryback of the Company's estimated NOL for the three months ended March 31, 2022 to the 2021 tax year. The recaptured tax credits were earned in 2019 but not utilized until 2021 due to NOL's generated in both 2019 and 2020. As of March 31, 2022, the Company had approximately $49.9 million of available tax credit carryforwards generated from its investments in tax credit partnerships which they expect to utilize in future periods. Tax credits provided by the underlying projects of the Company's historic tax credit partnership are typically available in the tax year in which the project is put into active service, whereas the tax credits provided by qualified affordable housing project tax credit partnerships are provided over approximately a ten year period. Significant Equity Method Investees As previously discussed, ProAssurance holds certain investments that are measured using the equity method of accounting, primarily investments in LPs/LLCs, which are carried as a part of Investment in Unconsolidated Subsidiaries on the Condensed Consolidated Balance Sheets. Each quarter, ProAssurance assesses the significance of its equity method investees. As of March 31, 2022 ProAssurance determined one equity method investee, Prime Storage Fund II, LP, to be significant. This fund invests primarily in self-storage real estate. As of March 31, 2021, ProAssurance determined one equity method investee, NB Private Equity Credit Opportunities Fund LP, to be significant. NB Private Equity Credit Opportunities Fund LP fund invests primarily in senior/junior debt instruments of private equity backed companies, including secured and unsecured loans, bonds and other instruments. The following table presents gross summarized financial information for significant funds, including the portion not attributable to ProAssurance, derived from the fund's financial statements which are prepared in accordance with GAAP. As the majority of ProAssurance's equity method investments report their results to the Company on a one quarter lag, the summarized financial information below is for the three months ended December 31, 2021 and 2020, respectively. (In thousands) Three Months Ended March 31, 2022 Three Months Ended March 31, 2021 Prime Storage Fund II LP NB Private Equity Credit Opportunities Fund LP Net investment income $ 28,691 $ 40,636 Net investment gains (losses) 22,438 14,587 Net change in unrealized appreciation (depreciation) 235,525 61,777 Net gain (loss) $ 286,654 $ 117,000 Net gain (loss) attributable to ProAssurance* $ 1,457 $ 2,056 *Represents ProAssurance's share of the fund's aggregate income or loss, which is included as a component of equity in earnings (loss) of unconsolidated subsidiaries in its Condensed Consolidated Statement of Income and Comprehensive Income for the three months ended March 31, 2022 and 2021. Net Investment Gains (Losses) Realized investment gains and losses are recognized on the first-in, first-out basis. The following table provides detailed information regarding net investment gains (losses): Three Months Ended (In thousands) 2022 2021 Gross realized gains, available-for-sale fixed maturities $ 1,187 $ 4,294 Gross realized (losses), available-for-sale fixed maturities (1,124) (187) Net realized gains (losses), trading fixed maturities (75) 72 Net realized gains (losses), equity investments (220) 4,189 Net realized gains (losses), other investments 650 3,196 Change in unrealized holding gains (losses), trading fixed maturities (326) (214) Change in unrealized holding gains (losses), equity investments (11,485) (2,937) Change in unrealized holding gains (losses), convertible securities, carried at fair value (2,476) (190) Other 363 626 Net investment gains (losses) $ (13,506) $ 8,849 For the three months ended March 31, 2022 and 2021, ProAssurance did not recognize any credit-related impairment losses in earnings or non-credit impairment losses in OCI. 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 impairment was recorded in OCI. Three Months Ended (In thousands) 2022 2021 Balance beginning of period $ — $ 552 Reductions due to: Securities sold during the period (realized) — (552) Balance March 31 $ — $ —

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For interim periods, ProAssurance generally utilizes the estimated annual effective tax rate method under which the Company determines its provision (benefit) for income taxes based on the current estimate of its annual effective tax rate. For the three months ended March 31, 2022, ProAssurance utilized the discrete effective tax rate method for recording income taxes after the estimated annual effective tax rate method produced an unreliable estimated effective annual tax rate. The discrete method is applied when the application of the estimated annual effective tax rate method is impractical and does not provide a reliable estimate of the annual effective tax rate. The Company believes the use of the discrete effective tax rate method is more appropriate than the annual effective tax rate method for the three months ended March 31, 2022 as minor changes in the Company's estimated ordinary income would have a significant effect on the estimated annual effective tax rate and would result in sizable variations in the customary relationship between income tax expense (benefit) and pre-tax accounting income (loss). ProAssurance will reevaluate its use of this method each quarter until the Company believes a return to the estimated annual effective tax rate method is deemed appropriate. For the three months ended March 31, 2021, ProAssurance utilized the estimated annual effective tax rate method. Under the estimated annual effective tax rate method, items which are unusual, infrequent, or that cannot be reliably estimated are considered in the effective tax rate in the period in which the item is included in income, and are referred to as discrete items. In calculating the Company's year-to-date income tax expense (benefit) under the estimated annual effective tax rate method, it includes the estimated benefit of tax credits for the year-to-date period based on the most recently available information provided by the tax credit partnerships; the actual amounts of credits provided by the tax credit partnerships may prove to be different than our estimates. The effect of such a difference is recognized in the period identified. For the three months ended March 31, 2022, the provision for income taxes is different from that which would be obtained by applying the statutory federal income tax rate to income before income taxes primarily because ProAssurance recognizes tax credit benefits transferred from tax credit partnership investments. In calculating the Company's year-to-date income tax expense (benefit), the Company included the estimated benefit of tax credits for the year-to-date period based on the most recently available information provided by the tax credit partnerships; the actual amounts of credits provided by the tax credit partnerships may prove to be different than the Company's estimates. The effect of such a difference is recognized in the period identified. ProAssurance had a receivable for U.S. federal and U.K. income taxes carried as a part of other assets as of March 31, 2022 and December 31, 2021 of $7.9 million in each period. At March 31, 2022 and December 31, 2021, the liability for unrecognized tax benefits, which is included in the total receivable for U.S. federal and U.K. income taxes, was $3.4 million in each period which included an accrued liability for interest of approximately $0.4 million in each period. NORCAL Acquisition As a result of the NORCAL acquisition, ProAssurance has U.S. federal NOL carryforwards which as of March 31, 2022 were approximately $43.0 million and will begin to expire in 2035. See Note 7 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K for more information. Coronavirus Aid, Relief and Economic Security Act

Reserve for Losses and Loss Adj

Reserve for Losses and Loss Adjustment Expenses	3 Months Ended
	Mar. 31, 2022
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. For a high proportion of the risks insured or reinsured by ProAssurance, 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 considerably 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. For additional information regarding ProAssurance's reserve for losses, see Note 1 and Note 10 of the Notes to Consolidated Financial Statements included in ProAssurance's December 31, 2021 report on Form 10-K. Activity in the reserve for losses and loss adjustment expenses is summarized as follows: (In thousands) Three Months Ended March 31, 2022 Three Months Ended March 31, 2021 Year Ended December 31, 2021 Balance, beginning of year $ 3,579,940 $ 2,417,179 $ 2,417,179 Less reinsurance recoverables on unpaid losses and loss adjustment expenses 451,741 385,087 385,087 Net balance, beginning of year 3,128,199 2,032,092 2,032,092 Net reserves acquired from NORCAL acquisition — — 1,089,103 Net losses: Current year (1) 214,753 154,634 797,732 Favorable development of reserves established in prior years, net (2) (5,330) (4,849) (45,483) Total 209,423 149,785 752,249 Paid related to: Current year (13,179) (10,513) (109,925) Prior years (185,977) (126,534) (635,320) Total paid (199,156) (137,047) (745,245) Net balance, end of period 3,138,466 2,044,830 3,128,199 Plus reinsurance recoverables on unpaid losses and loss adjustment expenses 464,780 393,420 451,741 Balance, end of period $ 3,603,246 $ 2,438,250 $ 3,579,940 (1) Current year net losses for the three months ended March 31, 2022 and year ended December 31, 2021 included $2.5 million and $6.7 million, respectively, of amortization of the negative VOBA associated with NORCAL's assumed unearned premium, which is being amortized over a period in proportion to the earn-out of the associated premium as a reduction to current accident year net losses (see Note 2 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K). (2) Net favorable prior year reserve development recognized for the three months ended March 31, 2022 and year ended December 31, 2021 included $2.9 million and $7.9 million, respectively, of amortization of the purchase accounting fair value adjustment on NORCAL's assumed net reserve and amortization of the negative VOBA associated with NORCAL's DDR reserve which is recorded as a reduction to prior accident year net losses and loss adjustment expenses (see Note 2 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K). ProAssurance has not recognized any development related to NORCAL's prior accident year reserves since the date of acquisition on May 5, 2021. Estimating liability reserves is complex and requires the use of many assumptions. As time passes and ultimate losses for prior years are either known or become subject to a more precise estimation, ProAssurance increases or decreases the reserve estimates established in prior periods. The net favorable loss development recognized in the three months ended March 31, 2022 primarily reflected overall favorable trends in claim closing patterns in the Workers' Compensation Insurance and Segregated Portfolio Cell Reinsurance segments. The net favorable loss development recognized in the Workers' Compensation Insurance segment is primarily related to the 2019 accident year and prior. The net favorable loss development recognized in the Segregated Portfolio Cell Reinsurance segment is primarily related to the 2019 and 2020 accident years. Net favorable development recognized during the three months ended March 31, 2022 was net of an increase in the Company's reserve for potential ECO/XPL claims of $4.0 million in the Specialty P&C segment. Excluding the increase in the ECO/XPL reserve and amortization of purchase accounting adjustments (see footnote 2 in the table above), ProAssurance recognized net favorable prior accident year reserve development of $5.0 million in the Specialty P&C segment, principally related to accident years 2019 through 2021. Consolidated net favorable loss development recognized in the three months ended March 31, 2022 was partially offset by unfavorable reserve development recognized in the Lloyd's Syndicates segment driven by certain catastrophe related losses. The net favorable loss development recognized in the three months ended March 31, 2021 primarily reflected a lower than anticipated claims severity trend (i.e., the average size of a claim) in the Specialty P&C segment, primarily related to the 2017 and 2018 accident years. The net favorable development also reflected overall favorable trends in claim closing patterns in the Workers' Compensation Insurance and Segregated Portfolio Cell Reinsurance segments. The net favorable loss development recognized in the Workers' Compensation Insurance segment is primarily related to the 2017 accident year and prior. The net favorable loss development recognized in the Segregated Portfolio Cell Reinsurance segment is primarily related to the 2018 and 2019 accident years. Consolidated net favorable loss development recognized in the three months ended March 31, 2021 was partially offset by unfavorable reserve development recognized in the Lloyd's Syndicates segment driven by certain property and catastrophe related losses. The net favorable loss development recognized for the year ended December 31, 2021 primarily reflected a lower than anticipated loss emergence in the Specialty P&C segment, primarily related to the 2015 through 2020 accident years. ProAssurance did not recognize any development related to NORCAL's prior accident year reserves in 2021. Net favorable prior accident year reserve development recognized in the Specialty P&C segment also included a $1.0 million reduction in our IBNR reserve for COVID-19 during the third quarter of 2021. The net favorable development also reflected overall favorable trends in claim closing patterns in the Workers' Compensation Insurance and Segregated Portfolio Cell Reinsurance segments. The net favorable loss development recognized in the Workers' Compensation Insurance segment is primarily related to the 2012 through 2017 accident years. The net favorable loss development recognized in the Segregated Portfolio Cell Reinsurance segment is primarily related to accident year 2015 and accident years 2018 through 2020. Consolidated net favorable loss development recognized in 2021 was partially offset by unfavorable reserve development recognized in the Lloyd's Syndicates segment driven by certain catastrophe related losses.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2022
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 December 31, 2021 report on Form 10-K. ProAssurance also has other direct actions against the Company unrelated to its claims activity which are evaluated and accounted for as a part of other liabilities. For these corporate legal actions, the Company evaluates each case separately and establishes what it believes is an appropriate reserve based on GAAP guidance related to contingent liabilities. As of March 31, 2022, there were no material reserves established for corporate legal actions. As a member of Lloyd's, ProAssurance has obligations to Syndicate 1729 including a Syndicate Credit Agreement and FAL requirements. The Syndicate Credit Agreement is an unconditional revolving credit agreement to the Premium Trust Fund of Syndicate 1729 for the purpose of providing working capital. At March 31, 2022, the maximum permitted borrowings under the Syndicate Credit Agreement were approximately £30.0 million (approximately $39.4 million at March 31, 2022). Effective July 1, 2022, maximum permitted borrowings will be reduced to £15.0 million (approximately $19.7 million at March 31, 2022) from £30.0 million under an amended Syndicate Credit Agreement executed in January 2022. The amended Syndicate Credit Agreement has a maturity date of June 30, 2023 and contains an annual auto-renewal feature which allows for ProAssurance to elect to non-renew if notice is given at least 30 days prior to the next auto-renewal date, which is one year prior to the maturity date. Under the Syndicate Credit Agreement, advances bear interest at 3.8% annually and may be repaid at any time but are repayable upon demand after June 30, 2023, subject to extension through the auto-renewal feature. As of March 31, 2022, there were no outstanding borrowings under the Syndicate Credit Agreement. ProAssurance provides FAL to support underwriting by Syndicate 1729 which is comprised of investment securities and cash and cash equivalents deposited with Lloyd's with a total fair value of approximately $37.0 million at March 31, 2022 (see Note 3). ProAssurance has entered into financial instrument transactions that may present off-balance sheet credit risk or market risk. These transactions include a short-term loan commitment and commitments to provide funding to non-public investment entities. Under the short-term loan commitment, ProAssurance has agreed to advance funds on a 30 day basis to a counterparty provided there is no violation of any condition established in the contract. As of March 31, 2022, ProAssurance had total funding commitments related to non-public investment entities as well as the short-term loan commitment of approximately $234.2 million which included the amount at risk if the full short-term loan is extended and the counterparties default. However, the credit risk associated with the short-term loan commitment is minimal as the counterparties to the contract are highly rated commercial institutions and to-date have been performing in accordance with their contractual obligations. ProAssurance’s expected credit losses associated with this short-term loan commitment were nominal in amount as of March 31, 2022. ProAssurance has previously entered into a services agreement with a company to provide data analytics services for certain product lines within the Company's HCPL book of business. In November 2021, ProAssurance executed an amendment to this services agreement which extended the Company's commitment an additional three years for an annual fee of approximately $3.5 million. In addition, the amended services agreement contains an annual one-year auto-extension feature unless either party elects to non-renew the services agreement by providing notice at least six-months prior to the end of the contract. ProAssurance incurred operating expenses associated with this services agreement of $0.9 million and $0.6 million for the three months ended March 31, 2022 and 2021, respectively. As of March 31, 2022, the remaining commitment under this agreement was estimated to be approximately $9.0 million. The purchase consideration in the NORCAL acquisition included contingent consideration. NORCAL policyholders who elected to receive NORCAL stock and tender it to ProAssurance are eligible for a share of contingent consideration in an amount of up to approximately $84 million depending upon the after-tax development of NORCAL's ultimate net losses between December 31, 2020 and December 31, 2023. The estimated fair value of this contingent consideration was $24 million as of March 31, 2022, which is unchanged from the acquisition date of May 5, 2021, and was derived utilizing a stochastic model. This estimate does not guarantee that contingent consideration will ultimately be paid. Depending on NORCAL's actual ultimate net loss development between December 31, 2020 and December 31, 2023, the actual amount due to eligible policyholders may be greater than or less than the $24 million current fair value estimate. See further discussion around the contingent consideration in Note 2 and further discussion on the NORCAL acquisition in Note 2 of the Notes to Consolidated Financial Statements included in ProAssurance's December 31, 2021 report on Form 10-K.

Debt

Debt	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Debt	Debt ProAssurance’s outstanding debt consisted of the following: ($ in thousands) March 31, December 31, Senior Notes due 2023, unsecured, interest at 5.3% annually $ 250,000 $ 250,000 Contribution Certificates due 2031, interest at 3.0% (effective interest rate at 4.35%) paid annually beginning April 2022 176,351 175,900 Total principal 426,351 425,900 Less unamortized debt issuance costs 821 914 Debt less unamortized debt issuance costs $ 425,530 $ 424,986 Revolving Credit Agreement ProAssurance has a Revolving Credit Agreement with seven participating lenders. The Revolving Credit Agreement, which expires November 2024 may be used for general corporate purposes, including, but not limited to, short-term working capital, share repurchases as authorized by the Board and support for other activities. ProAssurance's Revolving Credit Agreement permits borrowings up to $250 million, and has available a $50 million accordion feature which, if successfully subscribed, would expand the permitted borrowings to a maximum of $300 million. As of March 31, 2022 and December 31, 2021, there were no outstanding borrowings on the Revolving Credit Agreement. Covenant Compliance There are no financial covenants associated with the Senior Notes or the Contribution Certificates due 2023 and 2031, respectively. 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 Revolving Credit Agreement. Additional Information For additional information regarding ProAssurance's debt, see Note 13 of the Notes to Consolidated Financial Statements included in ProAssurance's December 31, 2021 report on Form 10-K.

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Shareholders' Equity	Shareholders’ Equity At March 31, 2022 and December 31, 2021, 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. ProAssurance declared cash dividends of $0.05 per share during the first quarter of both 2022 and 2021. Dividends declared during the 2022 and 2021 three-month periods totaled $2.7 million in each period. Any decision to pay future cash dividends is subject to the Board’s final determination after a comprehensive review of financial performance, future expectations and other factors deemed relevant by the Board. See Note 14 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K for additional information. At March 31, 2022, Board authorizations for the repurchase of common shares or the retirement of outstanding debt of $110 million remained available for use. ProAssurance did not repurchase any common shares during the three months ended March 31, 2022 or 2021. Other Comprehensive Income (Loss) and Accumulated Other Comprehensive Income (Loss) The following tables provide a detailed breakout of the components of AOCI and the amounts reclassified from AOCI to net income (loss). The tax effects of all amounts in the tables below, except for an immaterial amount of unrealized gains and losses on available-for-sale securities held at the Company's U.K. subsidiary, were computed using the enacted U.S. federal corporate tax rate of 21%. OCI included a deferred tax benefit of $38.2 million and $8.3 million for the three months ended March 31, 2022 and 2021, respectively. The changes in the balance of each component of AOCI for the three months ended March 31, 2022 and 2021 were as follows: (In thousands) Unrealized Investment Gains (Losses) Unrecognized Change in Defined Benefit and Post Retirement Liabilities Accumulated Other Comprehensive Income (Loss) Balance, December 31, 2021 $ 14,929 $ 1,355 $ 16,284 OCI, before reclassifications, net of tax (140,808) — (140,808) Amounts reclassified from AOCI, net of tax (28) (14) (42) Net OCI, current period (140,836) (14) (140,850) Balance, March 31, 2022 $ (125,907) $ 1,341 $ (124,566) (In thousands) Unrealized Investment Gains (Losses) Non-credit Impairments Unrecognized Change in Defined Benefit Plan Liabilities (1) Accumulated Other Comprehensive Income (Loss) Balance, December 31, 2020 $ 75,388 $ (57) $ (104) $ 75,227 OCI, before reclassifications, net of tax (30,415) — — (30,415) Amounts reclassified from AOCI, net of tax (3,347) 57 — (3,290) Net OCI, current period (33,762) 57 — (33,705) Balance, March 31, 2021 $ 41,626 $ — $ (104) $ 41,522 (1) For three months ended March 31, 2021, amounts represent the re-estimation of the defined benefit plan liability assumed in the Eastern acquisition. The defined benefit plan was frozen as to the earnings of additional benefits and the benefit plan liability was reestimated annually. The Company terminated Eastern's defined benefit plan during the third quarter of 2021.

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2022
Variable Interest Entities [Abstract]
Variable Interest Entities	Variable Interest Entities ProAssurance holds passive interests in a number of entities that are considered to be VIEs under GAAP guidance. ProAssurance's VIE interests principally consist of interests in LPs/LLCs formed for the purpose of achieving diversified equity and debt returns. ProAssurance's VIE interests, carried as a part of investment in unconsolidated subsidiaries, totaled $291.4 million at March 31, 2022 and $303.7 million at December 31, 2021. ProAssurance does not have power over the activities that most significantly impact the economic performance of these VIEs and thus is not the primary beneficiary. Investments in entities where ProAssurance holds a greater than minor interest but does not hold a controlling interest are accounted for using the equity method. Therefore, ProAssurance has not consolidated these VIEs. ProAssurance’s involvement with each of these VIEs is limited to its direct ownership interest in the VIE. Except for the funding commitments disclosed in Note 6, ProAssurance has no arrangements with any of these VIEs to provide other financial support to or on behalf of the VIE. At March 31, 2022, ProAssurance’s maximum loss exposure relative to these investments was limited to the carrying value of ProAssurance’s investment in the VIE. As a result of the Company's acquisition of NORCAL (see Note 2 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K), ProAssurance is the primary beneficiary of PPM RRG. While there is no direct ownership of PPM RRG by ProAssurance, it manages the business operations of PPM RRG through its management services agreement and has effective control of the PPM RRG's Board of Directors through an irrevocable voting proxy. The management services agreement allows ProAssurance to provide management and oversight services to the RRG, which includes the ability to make business decisions impacting the operations of PPM RRG. PPM RRG has a $5 million surplus note to NORCAL which is its only source of capital. ProAssurance has consolidated the account balances and transactions of PPM RRG beginning on the NORCAL acquisition date of May 5, 2021. At March 31, 2022, approximately $141 million of ProAssurance's assets and approximately $141 million of its liabilities included on the Condensed Consolidated Balance Sheet were related to PPM RRG.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Earnings (Loss) 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 restricted share units and performance share units have vested. The following table provides a reconciliation between the Company's basic weighted average number of common shares outstanding to its diluted weighted average number of common shares outstanding: (In thousands, except per share data) Three Months Ended 2022 2021 Weighted average number of common shares outstanding, basic 54,012 53,918 Dilutive effect of securities: Restricted Share Units 114 76 Performance Share Units 17 4 Weighted average number of common shares outstanding, diluted 54,143 53,998 Effect of dilutive shares on earnings (loss) per share $ — $ — Dilutive common share equivalents are reflected in the earnings (loss) per share calculation while antidilutive common share equivalents are not reflected in the earnings (loss) per share calculation. For the three months ended March 31, 2022, all incremental common share equivalents were not included in the computation of diluted earnings (loss) per share because to do so would have been antidilutive for the period. There were no antidilutive common share equivalents for the three months ended March 31, 2021.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2022
Segment Reporting [Abstract]
Segment Information	Segment Information ProAssurance's segments are based on the Company's internal management reporting structure for which financial results are regularly evaluated by the Company's CODM to determine resource allocation and assess operating performance. The Company continually assesses its internal management reporting structure and information evaluated by its CODM to determine whether any changes have occurred that would impact its segment reporting structure. The Company operates in five segments that are organized around the nature of the products and services provided: Specialty P&C, Workers' Compensation Insurance, Segregated Portfolio Cell Reinsurance, Lloyd's Syndicates and Corporate. Additional information regarding ProAssurance's segments is included in Note 18 of the Notes to Consolidated Financial Statements in ProAssurance’s December 31, 2021 report on Form 10-K. A description of each of ProAssurance's five operating and reportable segments follows. • Specialty P&C includes professional liability insurance and medical technology liability insurance. • Workers' Compensation Insurance includes workers' compensation insurance products which are provided primarily to employers with 1,000 or fewer employees. • Segregated Portfolio Cell Reinsurance includes the results (underwriting profit or loss, plus investment results, net of U.S. federal income taxes) of SPCs at Inova Re and Eastern Re, the Company's Cayman Islands SPC operations. • Lloyd's Syndicates includes the results from ProAssurance's participation in Lloyd's of London Syndicate 1729 and Syndicate 6131. ProAssurance's participation in the results of Syndicate 1729 for the 2022 underwriting year remains unchanged from the 2021 underwriting year at 5%. Effective January 1, 2022, Syndicate 6131 ceased underwriting on a quota share basis with Syndicate 1729 as Syndicate 6131's applicable business is retained within Syndicate 1729 beginning with the 2022 year of account. Due to the quarter lag, the Company's ceased participation in Syndicate 6131 will not be reflected in the Company's results until the second quarter of 2022. • Corporate includes ProAssurance's investment operations and excludes those reported in the Company's Segregated Portfolio Cell Reinsurance and Lloyd's Syndicates segments. In addition, this segment includes corporate expenses, interest expense. U.S. income taxes and non-premium revenues generated outside of the Company's insurance entities. The accounting policies of the segments are described in Note 1 of the Notes to Consolidated Financial Statements in ProAssurance’s December 31, 2021 report on Form 10-K. ProAssurance evaluates the performance of its Specialty P&C and Workers' Compensation Insurance segments based on before tax underwriting profit or loss. ProAssurance evaluates the performance of its Segregated Portfolio Cell Reinsurance segment based on operating profit or loss, which includes investment results of investment assets solely allocated to SPC operations, net of U.S. federal income taxes. Performance of the Lloyd's Syndicates segment is evaluated based on operating profit or loss, which includes investment results of investment assets solely allocated to Lloyd's Syndicate 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, other than the investments discussed above that are solely allocated to the Segregated Portfolio Cell Reinsurance and Lloyd's Syndicates segments, and other assets are not managed at the segment level. The tabular information that follows shows the financial results of the Company's reportable segments reconciled to results reflected in the Condensed Consolidated Statements of Income and Comprehensive Income. Beginning in the second quarter of 2021, transaction-related costs rose to a significant level; therefore, management determined that transaction-related costs will not be included in a segment on a prospective basis beginning in the second quarter of 2021 as ProAssurance does not consider these costs in assessing the financial performance of any of its operating or reportable segments. As a result, transaction-related costs are included in the reconciliation of segment results to consolidated results for the three months ended March 31, 2022. Financial results by segment were as follows: Three Months Ended March 31, 2022 (In thousands) Specialty P&C Workers' Compensation Insurance Segregated Portfolio Cell Reinsurance Lloyd's Syndicates Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 197,967 $ 40,684 $ 19,314 $ 7,746 $ — $ — $ 265,711 Net investment income — — 112 211 20,120 — 20,443 Equity in earnings (loss) of unconsolidated subsidiaries — — — — 7,620 — 7,620 Net investment gains (losses) — — (711) (399) (12,396) — (13,506) Other income (expense) (1) 1,019 682 1 134 2,065 (1,097) 2,804 Net losses and loss adjustment expenses (2) (165,958) (27,211) (11,491) (4,763) — — (209,423) Underwriting, policy acquisition and operating expenses (1)(2) (42,878) (13,001) (4,369) (2,709) (8,739) 1,097 (70,599) SPC U.S. federal income tax expense (3) — — (642) — — — (642) SPC dividend (expense) income — — (2,367) — — — (2,367) Interest expense — — — — (4,441) — (4,441) Income tax benefit (expense) — — — — 1,770 — 1,770 Segment results $ (9,850) $ 1,154 $ (153) $ 220 $ 5,999 $ — (2,630) Reconciliation of segments to consolidated results: Transaction-related costs, net (4) (930) Net income (loss) $ (3,560) Significant non-cash items: Depreciation and amortization, net of accretion $ 2,592 $ 874 $ 370 $ 14 $ 6,500 $ — $ 10,350 Three Months Ended March 31, 2021 (In thousands) Specialty P&C Workers' Compensation Insurance Segregated Portfolio Cell Reinsurance Lloyd's Syndicates Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 115,613 $ 40,011 $ 15,884 $ 15,850 $ — $ — $ 187,358 Net investment income — — 221 729 14,067 — 15,017 Equity in earnings (loss) of unconsolidated subsidiaries — — — — 6,788 — 6,788 Net investment gains (losses) — — 987 (115) 7,977 — 8,849 Other income (expense) (1) 469 392 1 221 1,894 (972) 2,005 Net losses and loss adjustment expenses (101,186) (26,207) (9,425) (12,967) — — (149,785) Underwriting, policy acquisition and operating expenses (1) (26,346) (12,286) (5,025) (6,591) (7,175) 972 (56,451) SPC U.S. federal income tax expense (3) — — (356) — — — (356) SPC dividend (expense) income — — (1,742) — — — (1,742) Interest expense — — — — (3,212) — (3,212) Income tax benefit (expense) — — — — (736) — (736) Segment results $ (11,450) $ 1,910 $ 545 $ (2,873) $ 19,603 $ — 7,735 Net income (loss) $ 7,735 Significant non-cash items: Depreciation and amortization, net of accretion $ 2,171 $ 903 $ 316 $ 15 $ 3,317 $ — $ 6,722 (1) Certain fees for services provided to the SPCs at Inova Re and Eastern Re are recorded as expenses within the Segregated Portfolio Cell Reinsurance segment and as other income within the Workers' Compensation Insurance segment. These fees are primarily SPC rental fees and are eliminated between segments in consolidation. (2) During the first quarter of 2022, ProAssurance revised its estimate of ULAE as a result of substantially integrating NORCAL into the Specialty P&C segment operations. The change in the Company's estimate of ULAE increased underwriting, policy acquisition and operating expenses with an offsetting decrease to net losses and loss adjustment expenses in the Specialty P&C segment; there was no impact on segment results for the three months ended March 31, 2022. See further discussion on this change in estimate in Note 1. (3) Represents the provision for U.S. federal income taxes for SPCs at Inova Re, which have elected to be taxed as a U.S. corporation under Section 953(d) of the Internal Revenue Code. U.S. federal income taxes are included in the total SPC net results and are paid by the individual SPCs. (4) Represents the transaction-related costs, after-tax, associated with the acquisition of NORCAL. Pre-tax transaction-related costs of approximately $1.2 million were included as a component of consolidated operating expense and the associated income tax benefit of approximately $0.3 million were included as a component of consolidated income tax benefit (expense) on the Condensed Consolidated Statements of Income and Comprehensive Income for the three months ended March 31, 2022. 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 U.S. Three Months Ended March 31 (In thousands) 2022 2021 Specialty P&C Segment Gross premiums earned: HCPL $ 175,547 $ 97,045 Small Business Unit 26,538 25,925 Medical Technology Liability 10,000 8,938 Other 194 152 Ceded premiums earned (14,312) (16,447) Segment net premiums earned 197,967 115,613 Workers' Compensation Insurance Segment Gross premiums earned: Traditional business 43,156 41,743 Alternative market business 17,878 16,889 Ceded premiums earned (20,350) (18,621) Segment net premiums earned 40,684 40,011 Segregated Portfolio Cell Reinsurance Segment Gross premiums earned: Workers' compensation (1) 17,178 16,115 HCPL (2) 4,486 1,852 Ceded premiums earned (2,350) (2,083) Segment net premiums earned 19,314 15,884 Lloyd's Syndicates Segment Gross premiums earned: Property and casualty 9,232 20,385 Ceded premiums earned (1,486) (4,535) Segment net premiums earned 7,746 15,850 Consolidated net premiums earned $ 265,711 $ 187,358 (1) Premium for all periods is assumed from the Workers' Compensation Insurance segment. (2) Premium for all periods is assumed from the Specialty P&C segment.

Benefit Plans

Benefit Plans	3 Months Ended
	Mar. 31, 2022
Retirement Benefits [Abstract]
Benefit Plans	Benefit Plans ProAssurance assumed a defined benefit pension plan on May 5, 2021 as a result of its acquisition of NORCAL, which covers substantially all NORCAL employees (except those that were previous employees of Medicus Insurance Company and FD Insurance Company, employees of PPM RRG as well as new hires after December 31, 2013). Benefits are based on years of service and the employee’s average of the highest five years of annual compensation. Annual contributions to the defined benefit pension plan are not less than the minimum funding standards outlined in the Employee Retirement Income Security Act of 1974, as amended. ProAssurance makes contributions to the defined benefit pension plan with the goal of ensuring that it is adequately funded to meet its future obligations. ProAssurance did not make any contributions to the pension plan during the three months ended March 31, 2022 and does not anticipate making any contributions for the remainder of 2022. The defined benefit pension plan no longer has future service accruals or compensation increases because this plan was frozen effective December 31, 2015. See Notes 2 and 19 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K for more information regarding ProAssurance's acquisition of NORCAL and defined benefit pension plan, respectively. The components of the net periodic benefit cost (income) for the three months ended March 31, 2022 were as follows: ($ in thousands) Three Months Ended March 31, 2022 Components of net periodic benefit cost (income): Interest cost $ 711 Expected return on Plan assets (989) Total net periodic benefit cost (income)* $ (278) *Net periodic benefit cost (income) is included as a component of operating expense on the Condensed Consolidated Statements of Income and Comprehensive Income for the three months ended March 31, 2022.

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of PresentationThe accompanying unaudited Condensed Consolidated Financial Statements include the accounts of ProAssurance Corporation, its wholly owned subsidiaries and VIEs in which ProAssurance is the primary beneficiary (ProAssurance, PRA or the Company). See Note 9 for more information on ProAssurance's VIE interests. 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 three months ended March 31, 2022 are not necessarily indicative of the results that may be expected for the year ending December 31, 2022. The accompanying Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and Notes contained in ProAssurance’s December 31, 2021 report on Form 10-K. ProAssurance operates in five reportable segments as follows: Specialty P&C, Workers' Compensation Insurance, Segregated Portfolio Cell Reinsurance, Lloyd's Syndicates and Corporate.
Accounting Policies	Accounting Policies The preparation of financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the reported amounts of assets and liabilities, revenues and expenses, and disclosures related to these amounts at the date of the financial statements. The Company evaluates these estimates and assumptions on an ongoing basis based on current and historical developments, market conditions, industry trends and other information that the Company believes to be reasonable under the circumstances, including the potential impacts of the COVID-19 pandemic (see "Item 1A, Risk Factors" in ProAssurance's December 31, 2021 report on Form 10-K for additional information). The Company can make no assurance that actual results will conform to its estimates and assumptions; reported results of operations may be materially affected by changes in these estimates and assumptions. The significant accounting policies followed by ProAssurance in making estimates that materially affect financial reporting are summarized in Note 1 of the Notes to Consolidated Financial Statements in ProAssurance’s December 31, 2021 report on Form 10-K.
Accounting Changes Adopted and Not Yet Adopted	Accounting Changes Adopted ProAssurance has not adopted any accounting changes during the three months ended March 31, 2022 that had a material effect on its results of operations, financial position or cash flows. Accounting Changes Not Yet Adopted ProAssurance is not aware of any accounting changes not yet adopted as of March 31, 2022 that could have a material impact on its results of operations, financial position or cash flows.

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets	Fair values of assets measured at fair value on a recurring basis as of March 31, 2022 and December 31, 2021 are shown in the following tables. Where applicable, 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. For more information on the valuation methodologies used regarding securities in the Level 2 and Level 3 categories, see Note 3 of the Notes to Consolidated Financial Statements in ProAssurance’s December 31, 2021 report on Form 10-K. March 31, 2022 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 $ — $ 225,676 $ — $ 225,676 U.S. Government-sponsored enterprise obligations — 16,733 — 16,733 State and municipal bonds — 492,291 — 492,291 Corporate debt, multiple observable inputs — 1,816,931 — 1,816,931 Corporate debt, limited observable inputs — — 53,325 53,325 Residential mortgage-backed securities — 417,276 572 417,848 Agency commercial mortgage-backed securities — 12,847 — 12,847 Other commercial mortgage-backed securities — 222,800 582 223,382 Other asset-backed securities — 433,639 8,149 441,788 Fixed maturities, trading — 49,421 — 49,421 Equity investments Financial 12,074 2,289 — 14,363 Utilities/Energy 1,099 — — 1,099 Industrial — — 2,500 2,500 Bond funds 170,338 — — 170,338 All other 15,625 — — 15,625 Short-term investments 210,122 23,223 — 233,345 Other investments 1,789 95,449 3,440 100,678 Other assets — 1,663 — 1,663 Total assets categorized within the fair value hierarchy $ 411,047 $ 3,810,238 $ 68,568 4,289,853 Assets carried at NAV, which approximates fair value and which are not categorized within the fair value hierarchy, reported as a part of: Investment in unconsolidated subsidiaries 267,125 Total assets at fair value $ 4,556,978 Liabilities: Other liabilities $ — $ — $ 24,000 $ 24,000 Total liabilities categorized within the fair value hierarchy $ — $ — $ 24,000 $ 24,000 December 31, 2021 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 $ — $ 238,507 $ — $ 238,507 U.S. Government-sponsored enterprise obligations — 20,234 — 20,234 State and municipal bonds — 519,196 — 519,196 Corporate debt, multiple observable inputs — 1,851,427 — 1,851,427 Corporate debt, limited observable inputs — — 47,129 47,129 Residential mortgage-backed securities — 453,644 297 453,941 Agency commercial mortgage-backed securities — 14,141 — 14,141 Other commercial mortgage-backed securities — 231,483 — 231,483 Other asset-backed securities — 451,459 6,205 457,664 Fixed maturities, trading — 43,670 — 43,670 Equity investments Financial 6,615 855 — 7,470 Industrial — — 2,500 2,500 Bond funds 187,059 — — 187,059 All other 17,778 — — 17,778 Short-term investments 174,944 42,043 — 216,987 Other investments 1,889 95,288 1,434 98,611 Other assets — 649 — 649 Total assets categorized within the fair value hierarchy $ 388,285 $ 3,962,596 $ 57,565 4,408,446 Assets carried at NAV, which approximates fair value and which are not categorized within the fair value hierarchy, reported as a part of: Investment in unconsolidated subsidiaries 270,816 Total assets at fair value $ 4,679,262 Liabilities: Other liabilities $ — $ — $ 24,000 $ 24,000 Total liabilities categorized within the fair value hierarchy $ — $ — $ 24,000 $ 24,000
Schedule of Quantitative Information Regarding Level 3 Valuations	Quantitative Information Regarding Level 3 Valuations Below is a quantitative information regarding securities in the Level 3 category, by security type: Fair Value at ($ in thousands) March 31, 2022 December 31, 2021 Valuation Technique Unobservable Input Range Assets: Corporate debt, limited observable inputs $53,325 $47,129 Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Residential mortgage-backed securities $572 $297 Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Other commercial mortgage-backed securities $582 $— Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Other asset-backed securities $8,149 $6,205 Market Comparable Comparability Adjustment 0% - 5% (2.5%) Discounted Cash Flows Comparability Adjustment 0% - 5% (2.5%) Equity investments $2,500 $2,500 Discounted Cash Flows Comparability Adjustment 0% - 10% (5%) Other investments $3,440 $1,434 Discounted Cash Flows Comparability Adjustment 0% - 10% (5%) Liabilities: Other liabilities $24,000 $24,000 Stochastic Model/Discounted Cash Flows N/A 0% - 10% (8%)
Schedule of Fair Value Measurements - Level 3 Assets	The following tables present summary information regarding changes in the fair value of assets measured using Level 3 inputs. March 31, 2022 Level 3 Fair Value Measurements - Assets (In thousands) Corporate Debt Asset-backed Securities Equity Investments Other Investments Total Balance, December 31, 2021 $ 47,129 $ 6,502 $ 2,500 $ 1,434 $ 57,565 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income — 1 — — 1 Net investment gains (losses) — — — 110 110 Included in other comprehensive income (993) (260) — — (1,253) Purchases 9,711 5,585 — 1,483 16,779 Sales (1,019) (5) — (116) (1,140) Transfers in 1,000 — — 529 1,529 Transfers out (2,503) (2,520) — — (5,023) Balance, March 31, 2022 $ 53,325 $ 9,303 $ 2,500 $ 3,440 $ 68,568 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ 64 $ 64 March 31, 2021 Level 3 Fair Value Measurements – Assets (In thousands) Corporate Debt Asset-backed Securities Other Investments Total Balance, December 31, 2020 $ 3,265 $ 8,693 $ — $ 11,958 Total gains (losses) realized and unrealized: Included in earnings, as a part of: Net investment income 1 (2) — (1) Net investment gains (losses) — (11) — (11) Included in other comprehensive income 20 (179) — (159) Purchases 4,875 7,357 — 12,232 Sales (17) (304) — (321) Transfers in 858 — 2,152 3,010 Transfers out (1,233) (6,241) — (7,474) Balance, March 31, 2021 $ 7,769 $ 9,313 $ 2,152 $ 19,234 Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end $ — $ — $ — $ —
Schedule of Investments in LLCs and Limited Partnerships	The amount of ProAssurance's unfunded commitments related to these investments as of March 31, 2022 and fair values of these investments as of March 31, 2022 and December 31, 2021 were as follows: Unfunded Fair Value (In thousands) March 31, March 31, December 31, Investment in unconsolidated subsidiaries: Private debt funds (1) $4,515 $ 17,674 $ 18,465 Long/short equity funds (2) None 209 655 Non-public equity funds (3) $55,591 158,286 160,219 Credit funds (4) $51,868 45,174 47,300 Strategy focused funds (5) $28,244 45,782 44,177 Total investments carried at NAV $ 267,125 $ 270,816 Below is additional information regarding each of the investments listed in the table above as of March 31, 2022. (1) This investment is 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, while 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 three (2) This investment holds primarily long and short North American equities and targets absolute returns using strategies designed to take advantage of market opportunities. Redemptions are permitted; however, 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. (3) This investment is comprised of interests in multiple unrelated LP funds, each structured to provide capital appreciation through diversified investments in private equity, which can include investments in buyout, venture capital, debt including senior, second lien and mezzanine, distressed debt, collateralized loan obligations and other private equity-oriented LPs. Two of the LPs allow redemption by terms set forth in the LP agreements; 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 ten years. (4) This investment is comprised of multiple unrelated LP funds. Two funds seek to obtain superior risk-adjusted absolute returns through a diversified portfolio of debt securities, including bonds, loans and other asset-backed instruments. The remaining funds focus on private middle market company mezzanine and senior secured loans, opportunities across the credit spectrum, mortgage backed-loans, as well as various types of loan-backed investments. One fund allows redemptions at any quarter-end with prior notice requirements of 180 days, while two other funds allow for redemptions with consent of the General Partner. The remaining funds do not allow redemptions. For the funds that do not allow redemptions, income and capital are to be periodically distributed at the discretion of the LP over time frames throughout the remaining life of the funds. (5) This investment is comprised of multiple unrelated LPs/LLCs funds. One fund is an LLC focused on investing in North American consumer products companies, comprised of equity and equity-related securities, as well as debt instruments. A second fund is focused on aircraft investments, along with components and assets related to aircrafts. For both funds, redemptions are not permitted. Another fund is an LP focused on North American energy infrastructure assets that allows redemption with consent of the General Partner. The remaining funds are real estate focused LPs, one of which allows for redemption with prior notice.
Schedule of Financial Instruments Not Measured at Fair Value	The following table provides the estimated fair value of the Company's financial instruments that, in accordance with GAAP for the type of investment, are measured using a methodology other than fair value. Fair values provided primarily fall within the Level 3 fair value category. March 31, 2022 December 31, 2021 (In thousands) Carrying Fair Carrying Fair Financial assets: BOLI $ 80,879 $ 80,879 $ 81,767 $ 81,767 Other investments $ 3,198 $ 3,198 $ 3,183 $ 3,183 Other assets $ 33,029 $ 33,016 $ 40,581 $ 40,583 Financial liabilities: Senior notes due 2023* $ 250,000 $ 255,913 $ 250,000 $ 264,000 Contribution Certificates $ 176,351 $ 161,533 $ 175,900 $ 179,892 Other liabilities $ 31,446 $ 31,446 $ 52,332 $ 52,332 * Carrying value excludes unamortized debt issuance costs.

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2022
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-For-Sale Fixed Maturities	Available-for-sale fixed maturities at March 31, 2022 and December 31, 2021 included the following: March 31, 2022 (In thousands) Amortized Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Fixed maturities, available-for-sale U.S. Treasury obligations $ 237,899 $ 240 $ 12,463 $ 225,676 U.S. Government-sponsored enterprise obligations 17,650 15 932 16,733 State and municipal bonds 511,863 1,368 20,940 492,291 Corporate debt 1,955,390 4,593 89,727 1,870,256 Residential mortgage-backed securities 441,565 2,142 25,859 417,848 Agency commercial mortgage-backed securities 13,231 46 430 12,847 Other commercial mortgage-backed securities 232,924 471 10,013 223,382 Other asset-backed securities 451,052 2,065 11,329 441,788 $ 3,861,574 $ 10,940 $ 171,693 $ 3,700,821 December 31, 2021 (In thousands) Amortized Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Fixed maturities, available-for-sale U.S. Treasury obligations $ 239,765 $ 1,166 $ 2,424 $ 238,507 U.S. Government-sponsored enterprise obligations 20,467 29 262 20,234 State and municipal bonds 511,750 9,620 2,174 519,196 Corporate debt 1,884,455 29,050 14,949 1,898,556 Residential mortgage-backed securities 455,438 4,254 5,751 453,941 Agency commercial mortgage-backed securities 13,909 294 62 14,141 Other commercial mortgage-backed securities 231,226 2,530 2,273 231,483 Other asset-backed securities 457,837 2,747 2,920 457,664 $ 3,814,847 $ 49,690 $ 30,815 $ 3,833,722
Schedule of Available-For-Sale Securities by Contractual Maturity	The recorded cost basis and estimated fair value of available-for-sale fixed maturities at March 31, 2022, 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 $ 237,899 $ 21,181 $ 128,387 $ 74,586 $ 1,522 $ 225,676 U.S. Government-sponsored enterprise obligations 17,650 1,798 11,029 3,774 132 16,733 State and municipal bonds 511,863 22,193 159,219 188,721 122,158 492,291 Corporate debt 1,955,390 141,092 848,525 774,223 106,416 1,870,256 Residential mortgage-backed securities 441,565 417,848 Agency commercial mortgage-backed securities 13,231 12,847 Other commercial mortgage-backed securities 232,924 223,382 Other asset-backed securities 451,052 441,788 $ 3,861,574 $ 3,700,821
Schedule of Investments Held in an Unrealized Loss Position	The following tables provide summarized information with respect to investments held in an unrealized loss position at March 31, 2022 and December 31, 2021, including the length of time the investment had been held in a continuous unrealized loss position. March 31, 2022 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 $ 208,608 $ 12,463 $ 195,658 $ 11,629 $ 12,950 $ 834 U.S. Government-sponsored enterprise obligations 16,601 932 12,835 599 3,766 333 State and municipal bonds 372,603 20,940 357,967 19,551 14,636 1,389 Corporate debt 1,437,296 89,727 1,292,183 75,597 145,113 14,130 Residential mortgage-backed securities 367,247 25,859 316,182 20,314 51,065 5,545 Agency commercial mortgage-backed securities 9,835 430 9,695 416 140 14 Other commercial mortgage-backed securities 204,736 10,013 194,654 9,310 10,082 703 Other asset-backed securities 375,684 11,329 360,024 10,477 15,660 852 $ 2,992,610 $ 171,693 $ 2,739,198 $ 147,893 $ 253,412 $ 23,800 December 31, 2021 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 $ 190,054 $ 2,424 $ 181,689 $ 2,206 $ 8,365 $ 218 U.S. Government-sponsored enterprise obligations 16,287 262 16,287 262 — — State and municipal bonds 175,442 2,174 171,930 2,039 3,512 135 Corporate debt 945,196 14,949 866,731 11,828 78,465 3,121 Residential mortgage-backed securities 326,248 5,751 290,019 4,320 36,229 1,431 Agency commercial mortgage-backed securities 4,529 62 4,355 54 174 8 Other commercial mortgage-backed securities 151,827 2,273 145,467 1,884 6,360 389 Other asset-backed securities 278,915 2,920 271,463 2,796 7,452 124 $ 2,088,498 $ 30,815 $ 1,947,941 $ 25,389 $ 140,557 $ 5,426
Schedule of a Roll Forward of Cumulative Credit Losses Recorded in Earnings Related to Impaired Debt Securities	The following table presents a roll forward of the allowance for expected credit losses on available-for-sale fixed maturities for the three months ended March 31, 2021. Three Months Ended March 31, 2021 (In thousands) Corporate Debt Total Balance, at December 31, 2020 $ 552 $ 552 Reductions related to: Securities sold during the period (552) (552) Balance, at March 31, 2021 $ — $ —
Schedule of Other Information Regarding Available-For-Sale Securities	Other information regarding sales and purchases of fixed maturity available-for-sale securities is as follows: Three Months Ended March 31 (In millions) 2022 2021 Proceeds from sales (exclusive of maturities and paydowns) $ 63.5 $ 61.9 Purchases $ 231.6 $ 342.2
Schedule of Net Investment Income	Net investment income (loss) by investment category was as follows: Three Months Ended (In thousands) 2022 2021 Fixed maturities $ 21,544 $ 15,692 Equities 701 694 Short-term investments, including Other 426 273 BOLI (47) 444 Investment fees and expenses (2,181) (2,086) Net investment income $ 20,443 $ 15,017
Schedule of Investment in Unconsolidated Subsidiaries	ProAssurance's investment in unconsolidated subsidiaries were as follows: March 31, 2022 Carrying Value (In thousands) Percentage March 31, December 31, Qualified affordable housing project tax credit partnerships See below $ 10,036 $ 12,424 All other investments, primarily investment fund LPs/LLCs See below 311,366 323,152 $ 321,402 $ 335,576
Schedule of Equity Method Investments	The results recorded and tax credits recognized related to ProAssurance's tax credit partnership investments were as follows: Three Months Ended (In thousands) 2022 2021 Qualified affordable housing project tax credit partnerships Losses recorded $ 2,388 $ 3,368 Tax credits recognized $ 1,205 $ 3,324 Historic tax credit partnership* Losses (gains) recorded $ — $ (182) Tax credits recognized $ — $ 50 *ProAssurance holds a historic tax credit partnership which was fully amortized in 2020. This partnership generated investment returns by providing benefits to fund investors in the form of tax credits, tax deductible project operating losses and positive cash flows. ProAssurance received a distribution associated with this investment during the first quarter of 2021, as a result of positive cash flows from a completed project, which was recognized as an operating gain. (In thousands) Three Months Ended March 31, 2022 Three Months Ended March 31, 2021 Prime Storage Fund II LP NB Private Equity Credit Opportunities Fund LP Net investment income $ 28,691 $ 40,636 Net investment gains (losses) 22,438 14,587 Net change in unrealized appreciation (depreciation) 235,525 61,777 Net gain (loss) $ 286,654 $ 117,000 Net gain (loss) attributable to ProAssurance* $ 1,457 $ 2,056 *Represents ProAssurance's share of the fund's aggregate income or loss, which is included as a component of equity in earnings (loss) of unconsolidated subsidiaries in its Condensed Consolidated Statement of Income and Comprehensive Income for the three months ended March 31, 2022 and 2021.
Schedule of Net Realized Investment Gains (Losses)	Realized investment gains and losses are recognized on the first-in, first-out basis. The following table provides detailed information regarding net investment gains (losses): Three Months Ended (In thousands) 2022 2021 Gross realized gains, available-for-sale fixed maturities $ 1,187 $ 4,294 Gross realized (losses), available-for-sale fixed maturities (1,124) (187) Net realized gains (losses), trading fixed maturities (75) 72 Net realized gains (losses), equity investments (220) 4,189 Net realized gains (losses), other investments 650 3,196 Change in unrealized holding gains (losses), trading fixed maturities (326) (214) Change in unrealized holding gains (losses), equity investments (11,485) (2,937) Change in unrealized holding gains (losses), convertible securities, carried at fair value (2,476) (190) Other 363 626 Net investment gains (losses) $ (13,506) $ 8,849
Schedule of Cumulative Credit Losses Recorded in Earnings Related to Impaired Debt Securities for Which a Portion of the OTTI has been Recorded in OCI	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 impairment was recorded in OCI. Three Months Ended (In thousands) 2022 2021 Balance beginning of period $ — $ 552 Reductions due to: Securities sold during the period (realized) — (552) Balance March 31 $ — $ —

Reserve for Losses and Loss A_2

Reserve for Losses and Loss Adjustment Expenses (Tables)	3 Months Ended
	Mar. 31, 2022
Insurance [Abstract]
Schedule of Reserve for Losses and Loss Adjustment Expenses	Activity in the reserve for losses and loss adjustment expenses is summarized as follows: (In thousands) Three Months Ended March 31, 2022 Three Months Ended March 31, 2021 Year Ended December 31, 2021 Balance, beginning of year $ 3,579,940 $ 2,417,179 $ 2,417,179 Less reinsurance recoverables on unpaid losses and loss adjustment expenses 451,741 385,087 385,087 Net balance, beginning of year 3,128,199 2,032,092 2,032,092 Net reserves acquired from NORCAL acquisition — — 1,089,103 Net losses: Current year (1) 214,753 154,634 797,732 Favorable development of reserves established in prior years, net (2) (5,330) (4,849) (45,483) Total 209,423 149,785 752,249 Paid related to: Current year (13,179) (10,513) (109,925) Prior years (185,977) (126,534) (635,320) Total paid (199,156) (137,047) (745,245) Net balance, end of period 3,138,466 2,044,830 3,128,199 Plus reinsurance recoverables on unpaid losses and loss adjustment expenses 464,780 393,420 451,741 Balance, end of period $ 3,603,246 $ 2,438,250 $ 3,579,940 (1) Current year net losses for the three months ended March 31, 2022 and year ended December 31, 2021 included $2.5 million and $6.7 million, respectively, of amortization of the negative VOBA associated with NORCAL's assumed unearned premium, which is being amortized over a period in proportion to the earn-out of the associated premium as a reduction to current accident year net losses (see Note 2 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K). (2) Net favorable prior year reserve development recognized for the three months ended March 31, 2022 and year ended December 31, 2021 included $2.9 million and $7.9 million, respectively, of amortization of the purchase accounting fair value adjustment on NORCAL's assumed net reserve and amortization of the negative VOBA associated with NORCAL's DDR reserve which is recorded as a reduction to prior accident year net losses and loss adjustment expenses (see Note 2 of the Notes to Consolidated Financial Statements in ProAssurance's December 31, 2021 report on Form 10-K). ProAssurance has not recognized any development related to NORCAL's prior accident year reserves since the date of acquisition on May 5, 2021.

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Schedule of Outstanding Debt	ProAssurance’s outstanding debt consisted of the following: ($ in thousands) March 31, December 31, Senior Notes due 2023, unsecured, interest at 5.3% annually $ 250,000 $ 250,000 Contribution Certificates due 2031, interest at 3.0% (effective interest rate at 4.35%) paid annually beginning April 2022 176,351 175,900 Total principal 426,351 425,900 Less unamortized debt issuance costs 821 914 Debt less unamortized debt issuance costs $ 425,530 $ 424,986

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Schedule of Components of AOCI, Net of Tax	The changes in the balance of each component of AOCI for the three months ended March 31, 2022 and 2021 were as follows: (In thousands) Unrealized Investment Gains (Losses) Unrecognized Change in Defined Benefit and Post Retirement Liabilities Accumulated Other Comprehensive Income (Loss) Balance, December 31, 2021 $ 14,929 $ 1,355 $ 16,284 OCI, before reclassifications, net of tax (140,808) — (140,808) Amounts reclassified from AOCI, net of tax (28) (14) (42) Net OCI, current period (140,836) (14) (140,850) Balance, March 31, 2022 $ (125,907) $ 1,341 $ (124,566) (In thousands) Unrealized Investment Gains (Losses) Non-credit Impairments Unrecognized Change in Defined Benefit Plan Liabilities (1) Accumulated Other Comprehensive Income (Loss) Balance, December 31, 2020 $ 75,388 $ (57) $ (104) $ 75,227 OCI, before reclassifications, net of tax (30,415) — — (30,415) Amounts reclassified from AOCI, net of tax (3,347) 57 — (3,290) Net OCI, current period (33,762) 57 — (33,705) Balance, March 31, 2021 $ 41,626 $ — $ (104) $ 41,522 (1) For three months ended March 31, 2021, amounts represent the re-estimation of the defined benefit plan liability assumed in the Eastern acquisition. The defined benefit plan was frozen as to the earnings of additional benefits and the benefit plan liability was reestimated annually. The Company terminated Eastern's defined benefit plan during the third quarter of 2021.

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table provides a reconciliation between the Company's basic weighted average number of common shares outstanding to its diluted weighted average number of common shares outstanding: (In thousands, except per share data) Three Months Ended 2022 2021 Weighted average number of common shares outstanding, basic 54,012 53,918 Dilutive effect of securities: Restricted Share Units 114 76 Performance Share Units 17 4 Weighted average number of common shares outstanding, diluted 54,143 53,998 Effect of dilutive shares on earnings (loss) per share $ — $ —

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2022
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The tabular information that follows shows the financial results of the Company's reportable segments reconciled to results reflected in the Condensed Consolidated Statements of Income and Comprehensive Income. Beginning in the second quarter of 2021, transaction-related costs rose to a significant level; therefore, management determined that transaction-related costs will not be included in a segment on a prospective basis beginning in the second quarter of 2021 as ProAssurance does not consider these costs in assessing the financial performance of any of its operating or reportable segments. As a result, transaction-related costs are included in the reconciliation of segment results to consolidated results for the three months ended March 31, 2022. Financial results by segment were as follows: Three Months Ended March 31, 2022 (In thousands) Specialty P&C Workers' Compensation Insurance Segregated Portfolio Cell Reinsurance Lloyd's Syndicates Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 197,967 $ 40,684 $ 19,314 $ 7,746 $ — $ — $ 265,711 Net investment income — — 112 211 20,120 — 20,443 Equity in earnings (loss) of unconsolidated subsidiaries — — — — 7,620 — 7,620 Net investment gains (losses) — — (711) (399) (12,396) — (13,506) Other income (expense) (1) 1,019 682 1 134 2,065 (1,097) 2,804 Net losses and loss adjustment expenses (2) (165,958) (27,211) (11,491) (4,763) — — (209,423) Underwriting, policy acquisition and operating expenses (1)(2) (42,878) (13,001) (4,369) (2,709) (8,739) 1,097 (70,599) SPC U.S. federal income tax expense (3) — — (642) — — — (642) SPC dividend (expense) income — — (2,367) — — — (2,367) Interest expense — — — — (4,441) — (4,441) Income tax benefit (expense) — — — — 1,770 — 1,770 Segment results $ (9,850) $ 1,154 $ (153) $ 220 $ 5,999 $ — (2,630) Reconciliation of segments to consolidated results: Transaction-related costs, net (4) (930) Net income (loss) $ (3,560) Significant non-cash items: Depreciation and amortization, net of accretion $ 2,592 $ 874 $ 370 $ 14 $ 6,500 $ — $ 10,350 Three Months Ended March 31, 2021 (In thousands) Specialty P&C Workers' Compensation Insurance Segregated Portfolio Cell Reinsurance Lloyd's Syndicates Corporate Inter-segment Eliminations Consolidated Net premiums earned $ 115,613 $ 40,011 $ 15,884 $ 15,850 $ — $ — $ 187,358 Net investment income — — 221 729 14,067 — 15,017 Equity in earnings (loss) of unconsolidated subsidiaries — — — — 6,788 — 6,788 Net investment gains (losses) — — 987 (115) 7,977 — 8,849 Other income (expense) (1) 469 392 1 221 1,894 (972) 2,005 Net losses and loss adjustment expenses (101,186) (26,207) (9,425) (12,967) — — (149,785) Underwriting, policy acquisition and operating expenses (1) (26,346) (12,286) (5,025) (6,591) (7,175) 972 (56,451) SPC U.S. federal income tax expense (3) — — (356) — — — (356) SPC dividend (expense) income — — (1,742) — — — (1,742) Interest expense — — — — (3,212) — (3,212) Income tax benefit (expense) — — — — (736) — (736) Segment results $ (11,450) $ 1,910 $ 545 $ (2,873) $ 19,603 $ — 7,735 Net income (loss) $ 7,735 Significant non-cash items: Depreciation and amortization, net of accretion $ 2,171 $ 903 $ 316 $ 15 $ 3,317 $ — $ 6,722 (1) Certain fees for services provided to the SPCs at Inova Re and Eastern Re are recorded as expenses within the Segregated Portfolio Cell Reinsurance segment and as other income within the Workers' Compensation Insurance segment. These fees are primarily SPC rental fees and are eliminated between segments in consolidation. (2) During the first quarter of 2022, ProAssurance revised its estimate of ULAE as a result of substantially integrating NORCAL into the Specialty P&C segment operations. The change in the Company's estimate of ULAE increased underwriting, policy acquisition and operating expenses with an offsetting decrease to net losses and loss adjustment expenses in the Specialty P&C segment; there was no impact on segment results for the three months ended March 31, 2022. See further discussion on this change in estimate in Note 1. (3) Represents the provision for U.S. federal income taxes for SPCs at Inova Re, which have elected to be taxed as a U.S. corporation under Section 953(d) of the Internal Revenue Code. U.S. federal income taxes are included in the total SPC net results and are paid by the individual SPCs. (4) Represents the transaction-related costs, after-tax, associated with the acquisition of NORCAL. Pre-tax transaction-related costs of approximately $1.2 million were included as a component of consolidated operating expense and the associated income tax benefit of approximately $0.3 million were included as a component of consolidated income tax benefit (expense) on the Condensed Consolidated Statements of Income and Comprehensive Income for the three months ended March 31, 2022.
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 U.S. Three Months Ended March 31 (In thousands) 2022 2021 Specialty P&C Segment Gross premiums earned: HCPL $ 175,547 $ 97,045 Small Business Unit 26,538 25,925 Medical Technology Liability 10,000 8,938 Other 194 152 Ceded premiums earned (14,312) (16,447) Segment net premiums earned 197,967 115,613 Workers' Compensation Insurance Segment Gross premiums earned: Traditional business 43,156 41,743 Alternative market business 17,878 16,889 Ceded premiums earned (20,350) (18,621) Segment net premiums earned 40,684 40,011 Segregated Portfolio Cell Reinsurance Segment Gross premiums earned: Workers' compensation (1) 17,178 16,115 HCPL (2) 4,486 1,852 Ceded premiums earned (2,350) (2,083) Segment net premiums earned 19,314 15,884 Lloyd's Syndicates Segment Gross premiums earned: Property and casualty 9,232 20,385 Ceded premiums earned (1,486) (4,535) Segment net premiums earned 7,746 15,850 Consolidated net premiums earned $ 265,711 $ 187,358 (1) Premium for all periods is assumed from the Workers' Compensation Insurance segment. (2) Premium for all periods is assumed from the Specialty P&C segment.

Benefit Plans (Tables)

Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2022
Retirement Benefits [Abstract]
Schedule of Net Periodic Benefit Cost	The components of the net periodic benefit cost (income) for the three months ended March 31, 2022 were as follows: ($ in thousands) Three Months Ended March 31, 2022 Components of net periodic benefit cost (income): Interest cost $ 711 Expected return on Plan assets (989) Total net periodic benefit cost (income)* $ (278) *Net periodic benefit cost (income) is included as a component of operating expense on the Condensed Consolidated Statements of Income and Comprehensive Income for the three months ended March 31, 2022.

Basis of Presentation (Narrativ

Basis of Presentation (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)segment	Mar. 31, 2021USD ($)
Business Acquisition [Line Items]
Number of reportable segments | segment	5
Underwriting, policy acquisition and operating expenses	$ 70,599	$ 56,451
Net losses and loss adjustment expenses	209,423	$ 149,785
NORCAL Group
Business Acquisition [Line Items]
Underwriting, policy acquisition and operating expenses	7,300
Net losses and loss adjustment expenses	$ (7,300)

Fair Value Measurement (Assets

Fair Value Measurement (Assets Measured at Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Assets:
Fixed maturities, available-for-sale	$ 3,700,821	$ 3,833,722
Fixed maturities, trading	49,421	43,670
Equity investments	203,925	214,807
Level 3
Liabilities:
Other liabilities	24,000	24,000
U.S. Treasury obligations
Assets:
Fixed maturities, available-for-sale	225,676	238,507
U.S. Government-sponsored enterprise obligations
Assets:
Fixed maturities, available-for-sale	16,733	20,234
State and municipal bonds
Assets:
Fixed maturities, available-for-sale	492,291	519,196
Corporate debt, limited observable inputs | Level 3
Assets:
Fixed maturities, available-for-sale	53,325	47,129
Residential mortgage-backed securities
Assets:
Fixed maturities, available-for-sale	417,848	453,941
Agency commercial mortgage-backed securities
Assets:
Fixed maturities, available-for-sale	12,847	14,141
Other commercial mortgage-backed securities
Assets:
Fixed maturities, available-for-sale	223,382	231,483
Other asset-backed securities
Assets:
Fixed maturities, available-for-sale	441,788	457,664
Recurring
Assets:
Total assets categorized within the fair value hierarchy	4,556,978	4,679,262
Recurring | Level 1
Assets:
Fixed maturities, trading	0	0
Other assets	0	0
Total assets categorized within the fair value hierarchy	411,047	388,285
Liabilities:
Other liabilities	0	0
Total liabilities categorized within the fair value hierarchy	0	0
Recurring | Level 2
Assets:
Fixed maturities, trading	49,421	43,670
Other assets	1,663	649
Total assets categorized within the fair value hierarchy	3,810,238	3,962,596
Liabilities:
Other liabilities	0	0
Total liabilities categorized within the fair value hierarchy	0	0
Recurring | Level 3
Assets:
Fixed maturities, trading	0	0
Other assets	0	0
Total assets categorized within the fair value hierarchy	68,568	57,565
Liabilities:
Other liabilities	24,000	24,000
Total liabilities categorized within the fair value hierarchy	24,000	24,000
Recurring | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Fixed maturities, trading	49,421	43,670
Other assets	1,663	649
Total assets categorized within the fair value hierarchy	4,289,853	4,408,446
Liabilities:
Other liabilities	24,000	24,000
Total liabilities categorized within the fair value hierarchy	24,000	24,000
Recurring | U.S. Treasury obligations | Level 1
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | U.S. Treasury obligations | Level 2
Assets:
Fixed maturities, available-for-sale	225,676	238,507
Recurring | U.S. Treasury obligations | Level 3
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | U.S. Treasury obligations | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Fixed maturities, available-for-sale	225,676	238,507
Recurring | U.S. Government-sponsored enterprise obligations | Level 1
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | U.S. Government-sponsored enterprise obligations | Level 2
Assets:
Fixed maturities, available-for-sale	16,733	20,234
Recurring | U.S. Government-sponsored enterprise obligations | Level 3
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | U.S. Government-sponsored enterprise obligations | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Fixed maturities, available-for-sale	16,733	20,234
Recurring | State and municipal bonds | Level 1
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | State and municipal bonds | Level 2
Assets:
Fixed maturities, available-for-sale	492,291	519,196
Recurring | State and municipal bonds | Level 3
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | State and municipal bonds | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Fixed maturities, available-for-sale	492,291	519,196
Recurring | Corporate debt, multiple observable inputs | Level 1
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | Corporate debt, multiple observable inputs | Level 2
Assets:
Fixed maturities, available-for-sale	1,816,931	1,851,427
Recurring | Corporate debt, multiple observable inputs | Level 3
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | Corporate debt, multiple observable inputs | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Fixed maturities, available-for-sale	1,816,931	1,851,427
Recurring | Corporate debt, limited observable inputs | Level 1
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | Corporate debt, limited observable inputs | Level 2
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | Corporate debt, limited observable inputs | Level 3
Assets:
Fixed maturities, available-for-sale	53,325	47,129
Recurring | Corporate debt, limited observable inputs | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Fixed maturities, available-for-sale	53,325	47,129
Recurring | Residential mortgage-backed securities | Level 1
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | Residential mortgage-backed securities | Level 2
Assets:
Fixed maturities, available-for-sale	417,276	453,644
Recurring | Residential mortgage-backed securities | Level 3
Assets:
Fixed maturities, available-for-sale	572	297
Recurring | Residential mortgage-backed securities | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Fixed maturities, available-for-sale	417,848	453,941
Recurring | Agency commercial mortgage-backed securities | Level 1
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | Agency commercial mortgage-backed securities | Level 2
Assets:
Fixed maturities, available-for-sale	12,847	14,141
Recurring | Agency commercial mortgage-backed securities | Level 3
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | Agency commercial mortgage-backed securities | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Fixed maturities, available-for-sale	12,847	14,141
Recurring | Other commercial mortgage-backed securities | Level 1
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | Other commercial mortgage-backed securities | Level 2
Assets:
Fixed maturities, available-for-sale	222,800	231,483
Recurring | Other commercial mortgage-backed securities | Level 3
Assets:
Fixed maturities, available-for-sale	582	0
Recurring | Other commercial mortgage-backed securities | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Fixed maturities, available-for-sale	223,382	231,483
Recurring | Other asset-backed securities | Level 1
Assets:
Fixed maturities, available-for-sale	0	0
Recurring | Other asset-backed securities | Level 2
Assets:
Fixed maturities, available-for-sale	433,639	451,459
Recurring | Other asset-backed securities | Level 3
Assets:
Fixed maturities, available-for-sale	8,149	6,205
Recurring | Other asset-backed securities | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Fixed maturities, available-for-sale	441,788	457,664
Recurring | Financial | Level 1
Assets:
Equity investments	12,074	6,615
Recurring | Financial | Level 2
Assets:
Equity investments	2,289	855
Recurring | Financial | Level 3
Assets:
Equity investments	0	0
Recurring | Financial | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Equity investments	14,363	7,470
Recurring | Utilities/Energy | Level 1
Assets:
Equity investments	1,099
Recurring | Utilities/Energy | Level 2
Assets:
Equity investments	0
Recurring | Utilities/Energy | Level 3
Assets:
Equity investments	0
Recurring | Utilities/Energy | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Equity investments	1,099
Recurring | Industrial | Level 1
Assets:
Equity investments	0	0
Recurring | Industrial | Level 2
Assets:
Equity investments	0	0
Recurring | Industrial | Level 3
Assets:
Equity investments	2,500	2,500
Recurring | Industrial | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Equity investments	2,500	2,500
Recurring | Bond funds | Level 1
Assets:
Equity investments	170,338	187,059
Recurring | Bond funds | Level 2
Assets:
Equity investments	0	0
Recurring | Bond funds | Level 3
Assets:
Equity investments	0	0
Recurring | Bond funds | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Equity investments	170,338	187,059
Recurring | All other | Level 1
Assets:
Equity investments	15,625	17,778
Recurring | All other | Level 2
Assets:
Equity investments	0	0
Recurring | All other | Level 3
Assets:
Equity investments	0	0
Recurring | All other | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Equity investments	15,625	17,778
Recurring | Short-term investments | Level 1
Assets:
Short-term and other investments	210,122	174,944
Recurring | Short-term investments | Level 2
Assets:
Short-term and other investments	23,223	42,043
Recurring | Short-term investments | Level 3
Assets:
Short-term and other investments	0	0
Recurring | Short-term investments | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Short-term and other investments	233,345	216,987
Recurring | Other investments | Level 1
Assets:
Short-term and other investments	1,789	1,889
Recurring | Other investments | Level 2
Assets:
Short-term and other investments	95,449	95,288
Recurring | Other investments | Level 3
Assets:
Short-term and other investments	3,440	1,434
Recurring | Other investments | Fair Value, Inputs, Level 1, 2 and 3
Assets:
Short-term and other investments	100,678	98,611
Recurring | Equity investments | Fair Value Measured at Net Asset Value Per Share | Investment in unconsolidated subsidiaries
Assets:
Total assets categorized within the fair value hierarchy	$ 267,125	$ 270,816

Fair Value Measurement (Narrati

Fair Value Measurement (Narrative) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Credit Derivatives [Line Items]
Fair value of funded deferred compensation assets	$ 32,000,000	$ 39,500,000
Fair Value
Credit Derivatives [Line Items]
Deferred compensation liabilities	31,400,000	52,300,000
Fair Value, Nonrecurring
Credit Derivatives [Line Items]
Fair value, net asset (liability)	$ 0	0
NORCAL Group
Credit Derivatives [Line Items]
Fair value of funded deferred compensation assets		5,200,000
NORCAL Group | Fair Value
Credit Derivatives [Line Items]
Deferred compensation liabilities		$ 18,400,000
Other asset-backed securities | NRSRO, Rating A
Credit Derivatives [Line Items]
Credit quality percentage	100.00%
Other asset-backed securities | NRSRO, Rating BBB
Credit Derivatives [Line Items]
Credit quality percentage		100.00%

Fair Value Measurement (Quantit

Fair Value Measurement (Quantitative Information Regarding Level 3 Valuations) (Details) $ in Thousands	Mar. 31, 2022USD ($)	Dec. 31, 2021USD ($)
Assets:
Estimated Fair Value	$ 3,700,821	$ 3,833,722
Other investments	267,125	270,816
Level 3
Assets:
Equity investments	2,500	2,500
Other investments	3,440	1,434
Liabilities:
Other liabilities	$ 24,000	24,000
Level 3 | Comparability Adjustment | Minimum
Assets:
Equity securities measured at fair value	0
Level 3 | Comparability Adjustment | Maximum
Assets:
Equity securities measured at fair value	0.10
Level 3 | Comparability Adjustment | Weighted Average
Assets:
Equity securities measured at fair value	0.05
Level 3 | Comparability Adjustment | Discounted Cash Flows | Minimum
Assets:
Other investments, measurement input	0
Level 3 | Comparability Adjustment | Discounted Cash Flows | Maximum
Assets:
Other investments, measurement input	0.10
Level 3 | Comparability Adjustment | Discounted Cash Flows | Weighted Average
Assets:
Other investments, measurement input	0.05
Level 3 | Comparability Adjustment | Stochastic Model/Discounted Cash Flows | Minimum
Liabilities:
Other Liabilities, Measurement Input	0.00%
Level 3 | Comparability Adjustment | Stochastic Model/Discounted Cash Flows | Maximum
Liabilities:
Other Liabilities, Measurement Input	10.00%
Level 3 | Comparability Adjustment | Stochastic Model/Discounted Cash Flows | Weighted Average
Liabilities:
Other Liabilities, Measurement Input	8.00%
Corporate debt, limited observable inputs | Level 3
Assets:
Estimated Fair Value	$ 53,325	47,129
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Market Comparable Securities | Minimum
Assets:
Assets measured at fair value	0
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Market Comparable Securities | Maximum
Assets:
Assets measured at fair value	0.05
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Market Comparable Securities | Weighted Average
Assets:
Assets measured at fair value	0.025
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Discounted Cash Flows | Minimum
Assets:
Assets measured at fair value	0
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Discounted Cash Flows | Maximum
Assets:
Assets measured at fair value	0.05
Corporate debt, limited observable inputs | Level 3 | Comparability Adjustment | Discounted Cash Flows | Weighted Average
Assets:
Assets measured at fair value	0.025
Residential mortgage-backed securities | Level 3
Assets:
Estimated Fair Value	$ 572	297
Residential mortgage-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Minimum
Assets:
Assets measured at fair value	0
Residential mortgage-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Maximum
Assets:
Assets measured at fair value	0.05
Residential mortgage-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Weighted Average
Assets:
Assets measured at fair value	0.025
Residential mortgage-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Minimum
Assets:
Assets measured at fair value	0
Residential mortgage-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Maximum
Assets:
Assets measured at fair value	0.05
Residential mortgage-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Weighted Average
Assets:
Assets measured at fair value	0.025
Other commercial mortgage-backed securities | Level 3
Assets:
Estimated Fair Value	$ 582	0
Other commercial mortgage-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Minimum
Assets:
Assets measured at fair value	0
Other commercial mortgage-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Maximum
Assets:
Assets measured at fair value	0.05
Other commercial mortgage-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Weighted Average
Assets:
Assets measured at fair value	0.025
Other commercial mortgage-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Minimum
Assets:
Assets measured at fair value	0
Other commercial mortgage-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Maximum
Assets:
Assets measured at fair value	0.05
Other commercial mortgage-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Weighted Average
Assets:
Assets measured at fair value	0.025
Other asset-backed securities | Level 3
Assets:
Estimated Fair Value	$ 8,149	$ 6,205
Other asset-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Minimum
Assets:
Assets measured at fair value	0
Other asset-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Maximum
Assets:
Assets measured at fair value	0.05
Other asset-backed securities | Level 3 | Comparability Adjustment | Market Comparable Securities | Weighted Average
Assets:
Assets measured at fair value	0.025
Other asset-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Minimum
Assets:
Assets measured at fair value	0
Other asset-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Maximum
Assets:
Assets measured at fair value	0.05
Other asset-backed securities | Level 3 | Comparability Adjustment | Discounted Cash Flows | Weighted Average
Assets:
Assets measured at fair value	0.025

Fair Value Measurement (Level 3

Fair Value Measurement (Level 3 Assets and Liability) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 57,565	$ 11,958
Included in earnings, as a part of:
Included in other comprehensive income	(1,253)	(159)
Purchases	16,779	12,232
Sales	(1,140)	(321)
Transfers in	1,529	3,010
Transfers out	(5,023)	(7,474)
Ending balance	68,568	19,234
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	64	0
Net investment income
Included in earnings, as a part of:
Included in earnings	1	(1)
Net investment gains (losses)
Included in earnings, as a part of:
Included in earnings	110	(11)
Corporate Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	47,129	3,265
Included in earnings, as a part of:
Included in other comprehensive income	(993)	20
Purchases	9,711	4,875
Sales	(1,019)	(17)
Transfers in	1,000	858
Transfers out	(2,503)	(1,233)
Ending balance	53,325	7,769
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	0	0
Corporate Debt | Net investment income
Included in earnings, as a part of:
Included in earnings	0	1
Corporate Debt | Net investment gains (losses)
Included in earnings, as a part of:
Included in earnings	0	0
Asset-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	6,502	8,693
Included in earnings, as a part of:
Included in other comprehensive income	(260)	(179)
Purchases	5,585	7,357
Sales	(5)	(304)
Transfers in	0	0
Transfers out	(2,520)	(6,241)
Ending balance	9,303	9,313
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	0	0
Asset-backed Securities | Net investment income
Included in earnings, as a part of:
Included in earnings	1	(2)
Asset-backed Securities | Net investment gains (losses)
Included in earnings, as a part of:
Included in earnings	0	(11)
Equity Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	2,500
Included in earnings, as a part of:
Included in other comprehensive income	0
Purchases	0
Sales	0
Transfers in	0
Transfers out	0
Ending balance	2,500
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	0
Equity Investments | Net investment income
Included in earnings, as a part of:
Included in earnings	0
Equity Investments | Net investment gains (losses)
Included in earnings, as a part of:
Included in earnings	0
Other Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	1,434	0
Included in earnings, as a part of:
Included in other comprehensive income	0	0
Purchases	1,483	0
Sales	(116)	0
Transfers in	529	2,152
Transfers out	0	0
Ending balance	3,440	2,152
Change in unrealized gains (losses) included in earnings for the above period for Level 3 assets held at period-end	64	0
Other Investments | Net investment income
Included in earnings, as a part of:
Included in earnings	0	0
Other Investments | Net investment gains (losses)
Included in earnings, as a part of:
Included in earnings	$ 110	$ 0

Fair Value Measurement (Investm

Fair Value Measurement (Investments in LLCs and Limited Partnerships) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)fund	Dec. 31, 2021USD ($)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 267,125	$ 270,816
Private debt funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Number of limited partners in investment | fund	2
Number of limited partners to allow redemption by special consent | fund	1
Private debt funds | Minimum
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Liquidating investments remaining period	3 years
Private debt funds | Maximum
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Liquidating investments remaining period	8 years
Private debt funds | Investment in unconsolidated subsidiaries
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	$ 4,515
Fair Value	$ 17,674	18,465
Long/short equity funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Redemption percentage of LP at NAV for which initial payment is limited	90.00%
Payment period for redemption of LP valued at NAV	30 days
Long/short equity funds | Investment in unconsolidated subsidiaries
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	$ 0
Fair Value	$ 209	655
Non-public equity funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Liquidating investments remaining period	10 years
Non-public equity funds | Investment in unconsolidated subsidiaries
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	$ 55,591
Fair Value	$ 158,286	160,219
Credit funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Investment redemption notice period	180 days
Credit funds | Investment in unconsolidated subsidiaries
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	$ 51,868
Fair Value	45,174	47,300
Strategy focused funds | Investment in unconsolidated subsidiaries
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	28,244
Fair Value	$ 45,782	$ 44,177

Fair Value Measurement (Financi

Fair Value Measurement (Financial Instruments Not Measured at Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Carrying Value
Financial assets:
Other assets	$ 33,029	$ 40,581
Financial liabilities:
Other liabilities	31,446	52,332
Carrying Value | Senior Notes
Financial liabilities:
Debt instruments	250,000	250,000
Carrying Value | Contribution Certificates
Financial liabilities:
Debt instruments	176,351	175,900
Carrying Value | BOLI
Financial assets:
Short-term and other investments	80,879	81,767
Carrying Value | Other investments
Financial assets:
Short-term and other investments	3,198	3,183
Fair Value
Financial assets:
Other assets	33,016	40,583
Financial liabilities:
Other liabilities	31,446	52,332
Fair Value | Senior Notes
Financial liabilities:
Debt instruments	255,913	264,000
Fair Value | Contribution Certificates
Financial liabilities:
Debt instruments	161,533	179,892
Fair Value | BOLI
Financial assets:
Short-term and other investments	80,879	81,767
Fair Value | Other investments
Financial assets:
Short-term and other investments	$ 3,198	$ 3,183

Investments (Available-For-Sale

Investments (Available-For-Sale Fixed Maturities) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Reclassifications from AOCI to net income (loss):
Amortized Cost	$ 3,861,574	$ 3,814,847
Gross Unrealized Gains	10,940	49,690
Gross Unrealized Losses	171,693	30,815
Estimated Fair Value	3,700,821	3,833,722
U.S. Treasury obligations
Reclassifications from AOCI to net income (loss):
Amortized Cost	237,899	239,765
Gross Unrealized Gains	240	1,166
Gross Unrealized Losses	12,463	2,424
Estimated Fair Value	225,676	238,507
U.S. Government-sponsored enterprise obligations
Reclassifications from AOCI to net income (loss):
Amortized Cost	17,650	20,467
Gross Unrealized Gains	15	29
Gross Unrealized Losses	932	262
Estimated Fair Value	16,733	20,234
State and municipal bonds
Reclassifications from AOCI to net income (loss):
Amortized Cost	511,863	511,750
Gross Unrealized Gains	1,368	9,620
Gross Unrealized Losses	20,940	2,174
Estimated Fair Value	492,291	519,196
Corporate debt
Reclassifications from AOCI to net income (loss):
Amortized Cost	1,955,390	1,884,455
Gross Unrealized Gains	4,593	29,050
Gross Unrealized Losses	89,727	14,949
Estimated Fair Value	1,870,256	1,898,556
Residential mortgage-backed securities
Reclassifications from AOCI to net income (loss):
Amortized Cost	441,565	455,438
Gross Unrealized Gains	2,142	4,254
Gross Unrealized Losses	25,859	5,751
Estimated Fair Value	417,848	453,941
Agency commercial mortgage-backed securities
Reclassifications from AOCI to net income (loss):
Amortized Cost	13,231	13,909
Gross Unrealized Gains	46	294
Gross Unrealized Losses	430	62
Estimated Fair Value	12,847	14,141
Other commercial mortgage-backed securities
Reclassifications from AOCI to net income (loss):
Amortized Cost	232,924	231,226
Gross Unrealized Gains	471	2,530
Gross Unrealized Losses	10,013	2,273
Estimated Fair Value	223,382	231,483
Other asset-backed securities
Reclassifications from AOCI to net income (loss):
Amortized Cost	451,052	457,837
Gross Unrealized Gains	2,065	2,747
Gross Unrealized Losses	11,329	2,920
Estimated Fair Value	$ 441,788	$ 457,664

Investments (Available-For-Sa_2

Investments (Available-For-Sale Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Reclassifications from AOCI to net income (loss):
Amortized Cost	$ 3,861,574	$ 3,814,847
Total Fair Value	3,700,821	3,833,722
U.S. Treasury obligations
Reclassifications from AOCI to net income (loss):
Amortized Cost	237,899	239,765
Due in one year or less	21,181
Due after one year through five years	128,387
Due after five years through ten years	74,586
Due after ten years	1,522
Total Fair Value	225,676	238,507
U.S. Government-sponsored enterprise obligations
Reclassifications from AOCI to net income (loss):
Amortized Cost	17,650	20,467
Due in one year or less	1,798
Due after one year through five years	11,029
Due after five years through ten years	3,774
Due after ten years	132
Total Fair Value	16,733	20,234
State and municipal bonds
Reclassifications from AOCI to net income (loss):
Amortized Cost	511,863	511,750
Due in one year or less	22,193
Due after one year through five years	159,219
Due after five years through ten years	188,721
Due after ten years	122,158
Total Fair Value	492,291	519,196
Corporate debt
Reclassifications from AOCI to net income (loss):
Amortized Cost	1,955,390	1,884,455
Due in one year or less	141,092
Due after one year through five years	848,525
Due after five years through ten years	774,223
Due after ten years	106,416
Total Fair Value	1,870,256	1,898,556
Residential mortgage-backed securities
Reclassifications from AOCI to net income (loss):
Amortized Cost	441,565	455,438
Total Fair Value	417,848	453,941
Agency commercial mortgage-backed securities
Reclassifications from AOCI to net income (loss):
Amortized Cost	13,231	13,909
Total Fair Value	12,847	14,141
Other commercial mortgage-backed securities
Reclassifications from AOCI to net income (loss):
Amortized Cost	232,924	231,226
Total Fair Value	223,382	231,483
Other asset-backed securities
Reclassifications from AOCI to net income (loss):
Amortized Cost	451,052	457,837
Total Fair Value	$ 441,788	$ 457,664

Investments (Narrative) (Detail

Investments (Narrative) (Details)	3 Months Ended
	Mar. 31, 2022USD ($)securitybusinessissuerinvestmentpartnership	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)issuerpartnershipsecurity
Reclassifications from AOCI to net income (loss):
Number of investment in any entity or affiliates greater than 10% of stockholders' equity | investment	0
Threshold limit of investments based on shareholders' equity	10.00%
Securities on deposit with state insurance departments	$ 54,500,000
Business owned life insurance cost	42,000,000
Investment in unconsolidated subsidiaries	$ 321,402,000		$ 335,576,000
Number of LPs / LLCs with investment ownership percent over 25% (in businesses) | business	4
Portion of impairment losses recognized in other comprehensive income (loss) before taxes	$ 0	$ 0
Net impairment losses recognized in earnings	0	0
Tax Year 2019
Reclassifications from AOCI to net income (loss):
Tax credit	2,000,000
Tax Year 2039
Reclassifications from AOCI to net income (loss):
Tax credit	49,900,000
Tax Credit Partnership Investment Tax Credit Carryforward
Reclassifications from AOCI to net income (loss):
Tax credit	$ 1,200,000	$ 3,400,000
Tax Credit Partnerships Almost 100% Ownership
Reclassifications from AOCI to net income (loss):
Number of tax credit partnerships almost 100% ownership percentage | partnership	1		2
Investment in unconsolidated subsidiaries	$ 2,000,000		$ 3,200,000
Tax Credit Partnerships Almost 100% Ownership | Maximum
Reclassifications from AOCI to net income (loss):
Investment ownership percentage	100.00%		100.00%
Tax Credit Partnerships Less Than 20% Ownership
Reclassifications from AOCI to net income (loss):
Investment in unconsolidated subsidiaries	$ 8,000,000		$ 9,200,000
Tax Credit Partnerships Less Than 20% Ownership | Maximum
Reclassifications from AOCI to net income (loss):
Investment ownership percentage	20.00%
Other Limited Partnerships and Limited Liability Company, Greater Than 25% Ownership
Reclassifications from AOCI to net income (loss):
Investment ownership percentage	25.00%
Investment in unconsolidated subsidiaries	$ 49,300,000		49,000,000
Other Limited Partnerships and Limited Liability Company Less than 25% Ownership
Reclassifications from AOCI to net income (loss):
Investment in unconsolidated subsidiaries	262,100,000		$ 274,200,000
NORCAL Group
Reclassifications from AOCI to net income (loss):
Business owned life insurance cost	10,000,000
Fixed maturities
Reclassifications from AOCI to net income (loss):
Required FAL deposit	36,900,000
Cash and cash equivalents
Reclassifications from AOCI to net income (loss):
Required FAL deposit	$ 100,000
Non government-backed
Reclassifications from AOCI to net income (loss):
Debt securities in unrealized loss position (in securities) | security	2,504		1,766
Debt securities in unrealized loss position as percentage of total debt securities held	64.60%		45.80%
Issuers in unrealized loss position (in issuers) | issuer	1,288		998
Single greatest unrealized loss position	$ 2,300,000		$ 400,000
Second greatest unrealized loss position	$ 2,000,000

Investments (Investments Held i

Investments (Investments Held in a Loss Position) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair value
Fair Value	$ 2,992,610	$ 2,088,498
Less than 12 Months, Fair Value	2,739,198	1,947,941
More than 12 Months, Fair Value	253,412	140,557
Unrealized Loss
Unrealized Loss	171,693	30,815
Less than 12 Months, Unrealized Loss	147,893	25,389
More than 12 Months, Unrealized Loss	23,800	5,426
U.S. Treasury obligations
Fair value
Fair Value	208,608	190,054
Less than 12 Months, Fair Value	195,658	181,689
More than 12 Months, Fair Value	12,950	8,365
Unrealized Loss
Unrealized Loss	12,463	2,424
Less than 12 Months, Unrealized Loss	11,629	2,206
More than 12 Months, Unrealized Loss	834	218
U.S. Government-sponsored enterprise obligations
Fair value
Fair Value	16,601	16,287
Less than 12 Months, Fair Value	12,835	16,287
More than 12 Months, Fair Value	3,766	0
Unrealized Loss
Unrealized Loss	932	262
Less than 12 Months, Unrealized Loss	599	262
More than 12 Months, Unrealized Loss	333	0
State and municipal bonds
Fair value
Fair Value	372,603	175,442
Less than 12 Months, Fair Value	357,967	171,930
More than 12 Months, Fair Value	14,636	3,512
Unrealized Loss
Unrealized Loss	20,940	2,174
Less than 12 Months, Unrealized Loss	19,551	2,039
More than 12 Months, Unrealized Loss	1,389	135
Corporate debt
Fair value
Fair Value	1,437,296	945,196
Less than 12 Months, Fair Value	1,292,183	866,731
More than 12 Months, Fair Value	145,113	78,465
Unrealized Loss
Unrealized Loss	89,727	14,949
Less than 12 Months, Unrealized Loss	75,597	11,828
More than 12 Months, Unrealized Loss	14,130	3,121
Residential mortgage-backed securities
Fair value
Fair Value	367,247	326,248
Less than 12 Months, Fair Value	316,182	290,019
More than 12 Months, Fair Value	51,065	36,229
Unrealized Loss
Unrealized Loss	25,859	5,751
Less than 12 Months, Unrealized Loss	20,314	4,320
More than 12 Months, Unrealized Loss	5,545	1,431
Agency commercial mortgage-backed securities
Fair value
Fair Value	9,835	4,529
Less than 12 Months, Fair Value	9,695	4,355
More than 12 Months, Fair Value	140	174
Unrealized Loss
Unrealized Loss	430	62
Less than 12 Months, Unrealized Loss	416	54
More than 12 Months, Unrealized Loss	14	8
Other commercial mortgage-backed securities
Fair value
Fair Value	204,736	151,827
Less than 12 Months, Fair Value	194,654	145,467
More than 12 Months, Fair Value	10,082	6,360
Unrealized Loss
Unrealized Loss	10,013	2,273
Less than 12 Months, Unrealized Loss	9,310	1,884
More than 12 Months, Unrealized Loss	703	389
Other asset-backed securities
Fair value
Fair Value	375,684	278,915
Less than 12 Months, Fair Value	360,024	271,463
More than 12 Months, Fair Value	15,660	7,452
Unrealized Loss
Unrealized Loss	11,329	2,920
Less than 12 Months, Unrealized Loss	10,477	2,796
More than 12 Months, Unrealized Loss	$ 852	$ 124

Investments (Credit Losses Rela

Investments (Credit Losses Related to Debt Securities) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss beginning balance	$ 552
Securities sold during the period	(552)
Allowance for credit loss ending balance	0
Corporate Debt
Debt Securities, Available-for-sale, Allowance for Credit Loss [Roll Forward]
Allowance for credit loss beginning balance	552
Securities sold during the period	(552)
Allowance for credit loss ending balance	$ 0

Investments (Sales and Purchase

Investments (Sales and Purchases of Available-for-Sale Securities) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Information regarding sales and purchases of available-for-sale securities
Proceeds from sales (exclusive of maturities and paydowns)	$ 63,500	$ 61,900
Purchases	$ 231,557	$ 342,197

Investments (Net Investment Inc

Investments (Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Net Investment Income
Investment fees and expenses	$ (2,181)	$ (2,086)
Net investment income	20,443	15,017
Fixed maturities
Net Investment Income
Investment income	21,544	15,692
Equities
Net Investment Income
Investment income	701	694
Short-term investments, including Other
Net Investment Income
Investment income	426	273
BOLI
Net Investment Income
Investment income	$ (47)	$ 444

Investments (Unconsolidated Sub

Investments (Unconsolidated Subsidiaries) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated subsidiaries	$ 321,402	$ 335,576
Qualified affordable housing project tax credit partnerships
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated subsidiaries	10,036	12,424
All other investments, primarily investment fund LPs/LLCs
Schedule of Equity Method Investments [Line Items]
Investment in unconsolidated subsidiaries	$ 311,366	$ 323,152

Investments (Equity in Earnings

Investments (Equity in Earnings (Loss) of Unconsolidated Subsidiaries) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Losses recorded	$ 2,388	$ 3,368
Tax credits recognized	1,205	3,324
Losses (gains) recorded	0	(182)
Tax credits recognized	$ 0	$ 50

Investments (Summarized Financi

Investments (Summarized Financial Information for Significant Investment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Schedule of Equity Method Investments [Line Items]
Net investment income	$ 20,443	$ 15,017
Total net investment gains (losses)	(13,506)	8,849
Net gain (loss) attributable to proassurance	(3,560)	7,735
Prime Storage Fund II LP
Schedule of Equity Method Investments [Line Items]
Net investment income	28,691
Net investment gains (losses)	22,438
Net change in unrealized appreciation (depreciation)	235,525
Total net investment gains (losses)	286,654
Net gain (loss) attributable to proassurance	$ 1,457
NB Private Equity Credit Opportunities Fund LP
Schedule of Equity Method Investments [Line Items]
Net investment income		40,636
Net investment gains (losses)		14,587
Net change in unrealized appreciation (depreciation)		61,777
Total net investment gains (losses)		117,000
Net gain (loss) attributable to proassurance		$ 2,056

Investments (Net Realized Inves

Investments (Net Realized Investment Gains (Losses)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Gross realized gains, available-for-sale fixed maturities	$ 1,187	$ 4,294
Gross realized (losses), available-for-sale fixed maturities	(1,124)	(187)
Net realized gains (losses), trading fixed maturities	(75)	72
Net realized gains (losses), equity investments	(220)	4,189
Net realized gains (losses), other investments	650	3,196
Change in unrealized holding gains (losses), trading fixed maturities	(326)	(214)
Change in unrealized holding gains (losses), equity investments	(11,485)	(2,937)
Change in unrealized holding gains (losses), convertible securities, carried at fair value	(2,476)	(190)
Other	363	626
Total net investment gains (losses)	$ (13,506)	$ 8,849

Investments (Roll Forward of Cu

Investments (Roll Forward of Cumulative Credit Losses Recorded in Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Balance beginning of period	$ 0	$ 552
Securities sold during the period (realized)	0	(552)
Balance ending of period	$ 0	$ 0

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Income Tax Contingency [Line Items]
Income taxes receivable	$ 7.9	$ 7.9
Unrecognized tax benefits	3.4	3.4
Accrued liability for interest related to unrecognized tax benefits	0.4	$ 0.4
Tax Year 2020
Income Tax Contingency [Line Items]
Operating loss carryforwards	33.3
Income tax refund, CARES Act	11.7
NORCAL Group
Income Tax Contingency [Line Items]
Operating loss carryforwards	$ 43

Reserve for Losses and Loss A_3

Reserve for Losses and Loss Adjustment Expenses (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2021
Liability for Claims and Claims Adjustment Expense [Line Items]
Minimum period for claims resolution	5 years
Summary of reserve for losses and loss adjustment expenses
Balance, beginning of year	$ 3,579,940		$ 2,417,179	$ 2,417,179
Less reinsurance recoverables on unpaid losses and loss adjustment expenses	451,741		385,087	385,087
Net balance, beginning of year	3,128,199		2,032,092	2,032,092
Net reserves acquired from NORCAL acquisition	0		0	1,089,103
Net losses:
Current year	214,753		154,634	797,732
Favorable development of reserves established in prior years, net	(5,330)		(4,849)	(45,483)
Total	209,423		149,785	752,249
Paid related to:
Current year	(13,179)		(10,513)	(109,925)
Prior years	(185,977)		(126,534)	(635,320)
Total paid	(199,156)		(137,047)	(745,245)
Net balance, end of period	3,138,466		2,044,830	3,128,199
Plus reinsurance recoverables on unpaid losses and loss adjustment expenses	464,780		393,420	451,741
Balance, end of period	3,603,246		$ 2,438,250	3,579,940
Specialty P&C Segment
Net losses:
Favorable development of reserves established in prior years, net	5,000	$ 1,000
Paid related to:
Increase in reserve for potential ECO/XPL claims	4,000
NORCAL Group
Net losses:
Current year	2,500			6,700
Favorable development of reserves established in prior years, net	$ 2,900			$ 7,900

Commitments and Contingencies (

Commitments and Contingencies (Details) £ in Millions	1 Months Ended	3 Months Ended
	Nov. 30, 2021	Mar. 31, 2022USD ($)	Mar. 31, 2021USD ($)	Jul. 01, 2022USD ($)	Jul. 01, 2022GBP (£)	Mar. 31, 2022GBP (£)	May 05, 2021USD ($)
NORCAL Group
Other Commitments [Line Items]
Contingent consideration, maximum estimate							$ 84,000,000
Contingent consideration		$ 24,000,000
Data Analytics Services
Other Commitments [Line Items]
Non-renew notice, period		6 months
Purchase commitment, period	3 years
Annual fee		$ 3,500,000
Extension period for long-term purchase commitment		1 year
Operating expense		$ 900,000	$ 600,000
Purchase obligation		9,000,000
Funding Commitments
Other Commitments [Line Items]
Commitments total		234,200,000
Lloyd's Syndicates
Other Commitments [Line Items]
Unused commitments to extend credit		$ 39,400,000				£ 30
Non-renew notice, period		30 days
Auto-renewal period prior to maturity date		1 year
Interest rate on revolving credit agreement		3.80%				3.80%
Outstanding borrowings		$ 0
Required FAL deposit		$ 37,000,000
Lloyd's Syndicates | Forecast
Other Commitments [Line Items]
Current lending capacity under revolving credit agreement				$ 19,700,000	£ 15

Debt (Details)

Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Gross debt	$ 426,351	$ 425,900
Less unamortized debt issuance costs	821	914
Debt less unamortized debt issuance costs	425,530	424,986
Senior notes due 2023 | Senior Notes
Debt Instrument [Line Items]
Gross debt	$ 250,000	250,000
Stated interest rate on debt	5.30%
Contribution Certificates
Debt Instrument [Line Items]
Gross debt	$ 176,351	$ 175,900
Stated interest rate on debt	3.00%
Effective interest rate on debt	4.35%

Debt (Narrative) (Details)

Debt (Narrative) (Details) - Line of Credit - Revolving Credit Facility	3 Months Ended
	Mar. 31, 2022USD ($)lender	Dec. 31, 2021USD ($)
Debt Instrument [Line Items]
Number of participating lenders | lender	7
Line of credit borrowing capacity	$ 250,000,000
Accordion feature borrowing capacity	50,000,000
Line of credit, borrowing capacity including accordion feature	300,000,000
Outstanding borrowing	$ 0	$ 0

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Equity [Abstract]
Common shares, shares authorized (in shares)	100,000,000		100,000,000
Preferred stock, shares authorized (in shares)	50,000,000		50,000,000
Cash dividends declared per common share (in usd per share)	$ 0.05	$ 0.05
Dividend declared	$ 2.7	$ 2.7
Total authorizations which remain available for use	$ 110
Common shares acquired (in shares)	0	0
Deferred tax (benefit) expense included in OCI	$ (38.2)	$ (8.3)

Shareholders' Equity (Roll Forw

Shareholders' Equity (Roll Forward of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 1,428,387	$ 1,349,210
OCI, before reclassifications, net of tax	(140,808)	(30,415)
Amounts reclassified from AOCI, net of tax	(42)	(3,290)
Net OCI, current period	(140,850)	(33,705)
Ending balance	1,281,768	1,321,316
Unrealized Investment Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	14,929	75,388
OCI, before reclassifications, net of tax	(140,808)	(30,415)
Amounts reclassified from AOCI, net of tax	(28)	(3,347)
Net OCI, current period	(140,836)	(33,762)
Ending balance	(125,907)	41,626
Non-credit Impairments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(57)
OCI, before reclassifications, net of tax		0
Amounts reclassified from AOCI, net of tax		57
Net OCI, current period		57
Ending balance		0
Unrecognized Change in Defined Benefit and Post Retirement Liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	1,355	(104)
OCI, before reclassifications, net of tax	0	0
Amounts reclassified from AOCI, net of tax	(14)	0
Net OCI, current period	(14)	0
Ending balance	1,341	(104)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	16,284	75,227
Ending balance	$ (124,566)	$ 41,522

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
VIEs carrying value	$ 6,058,598	$ 6,191,477
Liabilities	4,776,830	4,763,090
Variable Interest Entity, Primary Beneficiary | PPM RRG
Variable Interest Entity [Line Items]
VIEs carrying value	141,000
Surplus Notes	5,000
Liabilities	141,000
Equity investments | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
VIEs carrying value	$ 291,400	$ 303,700

Earnings (Loss) Per Share (Deta

Earnings (Loss) Per Share (Details) - $ / shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average number of common shares outstanding, basic (in shares)	54,012,000	53,918,000
Weighted average number of common shares outstanding, diluted (in shares)	54,143,000	53,998,000
Effect of dilutive shares on earnings (loss) per share (in usd per share)	$ 0	$ 0
Antidilutive shares excluded from computation of earnings per share (in shares)		0
Restricted Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dilutive securities (in shares)	114,000	76,000
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dilutive securities (in shares)	17,000	4,000

Segment Information (Narrative)

Segment Information (Narrative) (Details)	3 Months Ended
	Mar. 31, 2022segment
Segment Reporting Information [Line Items]
Number of reportable segments	5
Number of operating segments	5
Syndicate 1729
Segment Reporting Information [Line Items]
Proportion of capital provided to support Lloyd's Syndicate	5.00%

Segment Information (Financial

Segment Information (Financial Data by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Net premiums earned	$ 265,711	$ 187,358
Net investment income	20,443	15,017
Equity in earnings (loss) of unconsolidated subsidiaries	7,620	6,788
Net investment gains (losses)	(13,506)	8,849
Other income (expense)	2,804	2,005
Net losses and loss adjustment expenses	(209,423)	(149,785)
Underwriting, policy acquisition and operating expenses	(70,599)	(56,451)
SPC U.S. federal income taxes expense	(642)	(356)
SPC dividend (expense) income	(2,367)	(1,742)
Interest expense	(4,441)	(3,212)
Income tax benefit (expense)	1,770	(736)
Segment results	(2,630)	7,735
Net income (loss)	(3,560)	7,735
Depreciation and amortization, net of accretion	10,350	6,722
Income tax expense (benefit)	(2,017)	736
NORCAL Group
Segment Reporting Information [Line Items]
Net losses and loss adjustment expenses	7,300
Underwriting, policy acquisition and operating expenses	(7,300)
Transaction-related costs	(1,200)
Transaction-related costs	1,200
Income tax expense (benefit)	300
Specialty P&C
Segment Reporting Information [Line Items]
Net premiums earned	197,967	115,613
Workers' Compensation Insurance
Segment Reporting Information [Line Items]
Net premiums earned	40,684	40,011
Segregated Portfolio Cell Reinsurance
Segment Reporting Information [Line Items]
Net premiums earned	19,314	15,884
Lloyd's Syndicates
Segment Reporting Information [Line Items]
Net premiums earned	7,746	15,850
Operating segments | Specialty P&C
Segment Reporting Information [Line Items]
Net premiums earned	197,967	115,613
Net investment income	0	0
Equity in earnings (loss) of unconsolidated subsidiaries	0	0
Net investment gains (losses)	0	0
Other income (expense)	1,019	469
Net losses and loss adjustment expenses	(165,958)	(101,186)
Underwriting, policy acquisition and operating expenses	(42,878)	(26,346)
SPC U.S. federal income taxes expense	0	0
SPC dividend (expense) income	0	0
Interest expense	0	0
Income tax benefit (expense)	0	0
Segment results	(9,850)	(11,450)
Depreciation and amortization, net of accretion	2,592	2,171
Operating segments | Workers' Compensation Insurance
Segment Reporting Information [Line Items]
Net premiums earned	40,684	40,011
Net investment income	0	0
Equity in earnings (loss) of unconsolidated subsidiaries	0	0
Net investment gains (losses)	0	0
Other income (expense)	682	392
Net losses and loss adjustment expenses	(27,211)	(26,207)
Underwriting, policy acquisition and operating expenses	(13,001)	(12,286)
SPC U.S. federal income taxes expense	0	0
SPC dividend (expense) income	0	0
Interest expense	0	0
Income tax benefit (expense)	0	0
Segment results	1,154	1,910
Depreciation and amortization, net of accretion	874	903
Operating segments | Segregated Portfolio Cell Reinsurance
Segment Reporting Information [Line Items]
Net premiums earned	19,314	15,884
Net investment income	112	221
Equity in earnings (loss) of unconsolidated subsidiaries	0	0
Net investment gains (losses)	(711)	987
Other income (expense)	1	1
Net losses and loss adjustment expenses	(11,491)	(9,425)
Underwriting, policy acquisition and operating expenses	(4,369)	(5,025)
SPC U.S. federal income taxes expense	(642)	(356)
SPC dividend (expense) income	(2,367)	(1,742)
Interest expense	0	0
Income tax benefit (expense)	0	0
Segment results	(153)	545
Depreciation and amortization, net of accretion	370	316
Operating segments | Lloyd's Syndicates
Segment Reporting Information [Line Items]
Net premiums earned	7,746	15,850
Net investment income	211	729
Equity in earnings (loss) of unconsolidated subsidiaries	0	0
Net investment gains (losses)	(399)	(115)
Other income (expense)	134	221
Net losses and loss adjustment expenses	(4,763)	(12,967)
Underwriting, policy acquisition and operating expenses	(2,709)	(6,591)
SPC U.S. federal income taxes expense	0	0
SPC dividend (expense) income	0	0
Interest expense	0	0
Income tax benefit (expense)	0	0
Segment results	220	(2,873)
Depreciation and amortization, net of accretion	14	15
Operating segments | Corporate
Segment Reporting Information [Line Items]
Net premiums earned	0	0
Net investment income	20,120	14,067
Equity in earnings (loss) of unconsolidated subsidiaries	7,620	6,788
Net investment gains (losses)	(12,396)	7,977
Other income (expense)	2,065	1,894
Net losses and loss adjustment expenses	0	0
Underwriting, policy acquisition and operating expenses	(8,739)	(7,175)
SPC U.S. federal income taxes expense	0	0
SPC dividend (expense) income	0	0
Interest expense	(4,441)	(3,212)
Income tax benefit (expense)	1,770	(736)
Segment results	5,999	19,603
Depreciation and amortization, net of accretion	6,500	3,317
Inter-segment Eliminations
Segment Reporting Information [Line Items]
Net premiums earned	0	0
Net investment income	0	0
Equity in earnings (loss) of unconsolidated subsidiaries	0	0
Net investment gains (losses)	0	0
Other income (expense)	(1,097)	(972)
Net losses and loss adjustment expenses	0	0
Underwriting, policy acquisition and operating expenses	1,097	972
SPC U.S. federal income taxes expense	0	0
SPC dividend (expense) income	0	0
Interest expense	0	0
Income tax benefit (expense)	0	0
Segment results	0	0
Depreciation and amortization, net of accretion	0	$ 0
Segment reconciling items
Segment Reporting Information [Line Items]
Transaction-related costs	(930)
Transaction-related costs	$ 930

Segment Information (Gross Prem

Segment Information (Gross Premiums Earned and Reconciliation to Net Premiums) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Segment net premiums earned	$ 265,711	$ 187,358
Specialty P&C Segment
Segment Reporting Information [Line Items]
Ceded premiums earned	(14,312)	(16,447)
Segment net premiums earned	197,967	115,613
Specialty P&C Segment | HCPL
Segment Reporting Information [Line Items]
Gross premiums earned	175,547	97,045
Specialty P&C Segment | Small Business Unit
Segment Reporting Information [Line Items]
Gross premiums earned	26,538	25,925
Specialty P&C Segment | Medical Technology Liability
Segment Reporting Information [Line Items]
Gross premiums earned	10,000	8,938
Specialty P&C Segment | Other
Segment Reporting Information [Line Items]
Gross premiums earned	194	152
Workers' Compensation Insurance Segment
Segment Reporting Information [Line Items]
Ceded premiums earned	(20,350)	(18,621)
Segment net premiums earned	40,684	40,011
Workers' Compensation Insurance Segment | Traditional business
Segment Reporting Information [Line Items]
Gross premiums earned	43,156	41,743
Workers' Compensation Insurance Segment | Alternative market business
Segment Reporting Information [Line Items]
Gross premiums earned	17,878	16,889
Segregated Portfolio Cell Reinsurance Segment
Segment Reporting Information [Line Items]
Ceded premiums earned	(2,350)	(2,083)
Segment net premiums earned	19,314	15,884
Segregated Portfolio Cell Reinsurance Segment | HCPL
Segment Reporting Information [Line Items]
Gross premiums earned	4,486	1,852
Segregated Portfolio Cell Reinsurance Segment | Workers' compensation
Segment Reporting Information [Line Items]
Gross premiums earned	17,178	16,115
Lloyd's Syndicates Segment
Segment Reporting Information [Line Items]
Gross premiums earned	9,232	20,385
Ceded premiums earned	(1,486)	(4,535)
Segment net premiums earned	$ 7,746	$ 15,850

Benefit Plans (Components of Ne

Benefit Plans (Components of Net Periodic Benefit Cost Credit) (Details) - Pension Plan $ in Thousands	3 Months Ended
	Mar. 31, 2022USD ($)
Components of net periodic benefit cost (income):
Interest cost	$ 711
Expected return on Plan assets	(989)
Total net periodic benefit cost (income)	$ (278)