Mercury General (MCY) 10-Q 1 Nov 16 2016 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 27, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Entity Registrant Name	MERCURY GENERAL CORP
Entity Central Index Key	64,996
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		55,270,922

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
ASSETS
Fixed maturity securities (amortized cost $2,876,287; $2,804,275)	$ 2,972,927	$ 2,880,003
Equity securities (cost $359,193; $313,528)	374,458	315,362
Short-term investments (cost $206,744; $185,353)	206,851	185,277
Total investments	3,554,236	3,380,642
Cash	229,857	264,221
Receivables:
Premiums	474,586	436,621
Accrued investment income	41,143	42,747
Other	22,291	21,925
Total receivables	538,020	501,293
Deferred policy acquisition costs	206,757	201,762
Fixed assets (net of accumulated depreciation $314,290; $299,192)	155,730	157,131
Current income taxes	0	9,041
Deferred income taxes	13,521	23,231
Goodwill	42,796	42,796
Other intangible assets, net	27,144	31,702
Other assets	33,211	16,826
Total assets	4,801,272	4,628,645
Liabilities
Losses and loss adjustment expenses	1,244,553	1,146,688
Unearned premiums	1,102,151	1,049,314
Notes payable	290,000	290,000
Accounts payable and accrued expenses	119,508	122,571
Current income taxes	2,748	0
Other liabilities	226,855	199,187
Total liabilities	2,985,815	2,807,760
Commitments and contingencies
Shareholders’ equity:
Common stock without par value or stated value: Authorized 70,000 shares; issued and outstanding 55,271; 55,164	94,937	90,985
Additional paid-in capital	3,147	8,870
Retained earnings	1,717,373	1,721,030
Total shareholders’ equity	1,815,457	1,820,885
Total liabilities and shareholders’ equity	$ 4,801,272	$ 4,628,645

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Amortized cost on fixed maturities trading investments	$ 2,876,287	$ 2,804,275
Cost - equity security trading investments	359,193	313,528
Cost - short-term investments	206,744	185,353
Accumulated depreciation on fixed assets	$ 314,290	$ 299,192
Common Stock
Common stock, no par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized (in shares)	70,000,000	70,000,000
Common stock, shares issued (in shares)	55,271,000	55,164,000
Common stock, shares outstanding (in shares)	55,271,000	55,164,000

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues:
Net premiums earned	$ 790,850	$ 745,520	$ 2,337,256	$ 2,197,803
Net investment income	30,371	30,898	91,440	94,101
Net realized investment losses	(15,465)	(26,286)	54,973	(75,595)
Other	2,406	2,281	6,416	6,823
Total revenues	808,162	752,413	2,490,085	2,223,132
Expenses:
Losses and loss adjustment expenses	576,316	545,692	1,765,484	1,581,306
Policy acquisition costs	140,203	132,881	421,685	401,868
Other operating expenses	59,006	60,788	178,000	191,017
Interest	1,012	785	2,922	2,304
Total expenses	776,537	740,146	2,368,091	2,176,495
Income before income taxes	31,625	12,267	121,994	46,637
Income tax expense (benefit)	4,695	(3,003)	22,868	(4,437)
Net income	$ 26,930	$ 15,270	$ 99,126	$ 51,074
Net income per share:
Basic (in dollars per share)	$ 0.49	$ 0.28	$ 1.79	$ 0.93
Diluted (in dollars per share)	$ 0.49	$ 0.28	$ 1.79	$ 0.93
Weighted average shares outstanding:
Basic (in shares)	55,259	55,164	55,238	55,154
Diluted (in shares)	55,328	55,178	55,304	55,172
Dividends paid per share (in dollars per share)	$ 620	$ 0.6175	$ 1.86	$ 1.8525

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 99,126	$ 51,074
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	19,702	19,967
Net realized investment (gains) losses	(54,973)	75,595
Bond amortization, net	19,878	17,279
Excess tax benefit from exercise of stock options	(995)	(106)
Increase in premiums receivables	(37,965)	(46,952)
Change in current and deferred income taxes	22,494	(35,822)
Increase in deferred policy acquisition costs	(4,995)	(8,043)
Increase in unpaid losses and loss adjustment expenses	97,865	21,079
Increase in unearned premiums	52,838	56,562
Decrease in accounts payable and accrued expenses	(2,172)	(17,509)
Share-based compensation	(3,472)	2,946
Changes in other payables	2,539	10,255
Other, net	(319)	2,382
Net cash provided by operating activities	209,551	148,707
CASH FLOWS FROM INVESTING ACTIVITIES
Fixed maturities available-for-sale in nature: Purchases	(742,671)	(807,150)
Fixed maturities available-for-sale in nature: Sales	230,909	211,724
Fixed maturities available-for-sale in nature: Calls or maturities	421,737	283,311
Equity securities available-for-sale in nature:
Equity securities available-for-sale in nature:Purchases	(535,155)	(573,011)
Equity securities available-for-sale in nature:Sales	499,126	641,854
Equity securities available-for-sale in nature:Calls	0	2,378
Changes in securities payable and receivable	17,272	(6,658)
Changes in short-term investments and purchased options	(24,366)	210,274
Purchase of fixed assets	(12,874)	(16,384)
Sale of fixed assets	3	136
Business acquisition, net of cash acquired	0	7,771
Other, net	3,186	2,291
Net cash used in investing activities	(142,833)	(43,464)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividends paid to shareholders	(102,783)	(102,183)
Excess tax benefit from exercise of stock options	995	106
Proceeds from stock options exercised	706	2,111
Net cash used in financing activities	(101,082)	(99,966)
Net (decrease) increase in cash	(34,364)	5,277
Cash:
Beginning of the year	264,221	289,907
End of period	229,857	295,184
SUPPLEMENTAL CASH FLOW DISCLOSURE
Interest paid	2,797	2,228
Income taxes paid	$ 374	$ 31,385

General

General	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	General Consolidation and Basis of Presentation The consolidated financial statements include the accounts of Mercury General Corporation and its subsidiaries (referred to herein collectively as the "Company"). For the list of the Company’s subsidiaries, see Note 1 "Summary of Significant Accounting Policies" of the Notes to Consolidated Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 . The consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles ("GAAP"), which differ in some respects from those filed in reports to insurance regulatory authorities. All intercompany transactions and balances have been eliminated. The financial data of the Company included herein are unaudited. In the opinion of management, all material adjustments of a normal recurring nature have been made to present fairly the Company’s financial position at September 30, 2016 and the results of operations and cash flows for the periods presented. These statements were prepared in accordance with the instructions for interim reporting and do not contain certain information that was included in the annual financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 . Readers are urged to review the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 for more complete descriptions and discussions. Operating results and cash flows for the nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 . Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. These estimates require the Company to apply complex assumptions and judgments, and often the Company must make estimates about the effects of matters that are inherently uncertain and will likely change in subsequent periods. The most significant assumptions in the preparation of these condensed consolidated financial statements relate to reserves for losses and loss adjustment expenses. Actual results could differ from those estimates. See Note 1 "Summary of Significant Accounting Policies" of the Notes to Consolidated Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 . Earnings per Share Potentially dilutive securities representing approximately 22,000 and 74,000 shares of common stock for the three months ended September 30, 2016 and 2015 , respectively, and 29,000 and 52,000 shares of common stock for the nine months ended September 30, 2016 and 2015 , respectively, were excluded from the computation of diluted earnings per common share because their effect would have been anti-dilutive. Deferred Policy Acquisition Costs Deferred policy acquisition costs consist of commissions paid to outside agents, premium taxes, salaries, and certain other underwriting costs that are incremental or directly related to the successful acquisition of new and renewal insurance contracts and are amortized over the life of the related policy in proportion to premiums earned. Deferred policy acquisition costs are limited to the amount that will remain after deducting from unearned premiums and anticipated investment income, the estimated losses and loss adjustment expenses, and the servicing costs that will be incurred as premiums are earned. The Company’s deferred policy acquisition costs are further limited by excluding those costs not directly related to the successful acquisition of insurance contracts. Deferred policy acquisition cost amortization was $140.2 million and $132.9 million for the three months ended September 30, 2016 and 2015 , respectively, and $421.7 million and $401.9 million for the nine months ended September 30, 2016 and 2015 , respectively. The Company does not defer advertising expenditures but expenses them as incurred. The Company recorded net advertising expense of approximately $34 million and $39 million for the nine months ended September 30, 2016 and 2015 , respectively.

Recently Issued Accounting Stan

Recently Issued Accounting Standards	9 Months Ended
	Sep. 30, 2016
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recently Issued Accounting Standards	Recently Issued Accounting Standards In August 2016, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update ("ASU") 2016-15, "Classification of Certain Cash Receipts and Cash Payments (Topic 230)." The new guidance is intended to reduce diversity in how certain transactions are classified in the consolidated statement of cash flows. ASU 2016-15 will be effective for the Company beginning January 1, 2018. The Company is evaluating the impact that ASU 2016-15 will have on its consolidated financial statements and related disclosures. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326)." The amendments in this ASU replace the "incurred loss" methodology for recognizing credit losses with a methodology that reflects expected credit losses and requires consideration of a broader range of information including past events, current conditions and reasonable and supportable forecasts that affect the collectability of reported amounts of financial assets that are not accounted for at fair value through net income, such as loans, debt securities, trade receivables, net investment in leases, off-balance sheet credit exposures and reinsurance receivables. Under the current GAAP incurred loss methodology, recognition of the full amount of credit losses is generally delayed until the loss is probable of incurring. Current GAAP restricts the ability to record credit losses that are expected, but do not yet meet the probability threshold. ASU 2016-13 becomes effective for the Company beginning with the first quarter ending March 31, 2020. The Company is evaluating the impact that ASU 2016-13 will have on its consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU 2016-09, "Compensation - Stock Compensation (Topic 718)," which simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 becomes effective for the Company beginning January 1, 2017 and is required to be applied on a modified retrospective basis. The Company is evaluating the impact that ASU 2016-09 will have on its consolidated financial statements and related disclosures. In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)," which supersedes the guidance in Accounting Standards Codification ("ASC") 840, "Leases." ASU 2016-02 requires a lessee to recognize lease assets and lease liabilities resulting from all leases. ASU 2016-02 retains the distinction between a finance lease and an operating lease. Lessor accounting is largely unchanged from ASC 840. ASU 2016-02 becomes effective for the Company beginning January 1, 2019. However, in transition, the Company will be required to recognize and measure leases at the beginning of the earliest period (the first quarter of 2017) using a modified retrospective approach. The Company is evaluating the effect that ASU 2016-02 will have on its consolidated financial statements and related disclosures. In January 2016, the FASB issued ASU 2016-01, "Financial Instruments-Overall (Subtopic 825-10), Recognition and Measurement of Financial Assets and Financial Liabilities." The amendments in this ASU address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01: (1) requires equity investments (except those accounted for under the equity method or those that result in the consolidation of the investee) to be measured at fair value with changes in the fair value recognized in net income; (2) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (3) eliminates the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet; (4) requires the use of the exit price notion when measuring the fair value of financial instruments for disclosure purposes; (5) requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or the notes to the financial statements; and (6) clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity’s other deferred tax assets. ASU 2016-01 is effective for the Company beginning January 1, 2018. The Company does not anticipate that ASU 2016-01 will have a material impact on its consolidated financial statements and related disclosures. In May 2015, the FASB issued ASU 2015-09, "Financial Services -Insurance (Topic 944), Disclosures About Short-Duration Contracts." ASU 2015-09 requires insurance entities to provide additional disclosures related to claims liabilities. The additional disclosure requirements for the annual reports include: (1) claims development information by accident year, on a net of reinsurance basis, for the number of years for which claims incurred remain outstanding but not to exceed the most recent 10 years, and for the most recent reporting period presented, an insurer also needs to disclose the amount of total net outstanding claims for all accident years included in the claims development tables; (2) a reconciliation of claims development information and the aggregate carrying amount of the liability for unpaid claims and claim adjustment expenses; and (3) information about the claims frequency and the amount of the incurred-but-not-reported liabilities for each accident year presented. In addition, a description of the methodology used to determine the amounts disclosed is required. The roll forward of the liability for unpaid claims and claims adjustment expenses, currently required only for annual periods, will also be required for interim periods. ASU 2015-09 becomes effective for the Company beginning with the annual period ending December 31, 2016, and quarter periods beginning with the first quarter of 2017. Although the adoption of this standard will not have a material impact on its consolidated financial statements, the Company will expand the nature and extent of its insurance contracts disclosures. In February 2015, the FASB issued ASU 2015-02, "Consolidation (Topic 810), Amendments to the Consolidation Analysis" affecting the consolidation evaluation of limited partnerships and similar entities, fees paid to a decision maker or a service provider as a variable interest, and variable interests in a variable interest entity held by related parties of the reporting entities. The amendments became effective for the Company on January 1, 2016. As in previous GAAP, consolidation analysis under ASU 2015-02 contains two primary consolidation models: the voting control model and the variable interest ("VIE") model. An entity being evaluated for consolidation is required to first be subjected to the requirements of the VIE model. Only if the entity fails to meet the requirements to be consolidated under the VIE model, would the voting control consolidation model apply. The adoption of ASU 2015-02 did not have an impact on the Company's consolidated financial statements and related disclosures. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606)." ASU 2014-09 requires entities to apply a five-step model to determine the amount and timing of revenue recognition. The model specifies, among other criteria, that revenue should be recognized when an entity transfers control of goods or services to a customer in the amount to which the entity expects to be entitled. In August 2015, the FASB issued ASU 2015-14, "Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date," which deferred the effective date of ASU 2014-09 for the Company to January 1, 2018. Through the first half of 2016, the FASB issued additional ASUs on Topic 606 that do not change the core principle of the guidance in ASU 2014-09 but merely clarify certain aspects of it. The additional ASUs also become effective for the Company beginning January 1, 2018. The Company is evaluating the impact that these ASUs will have on its consolidated financial statements and related disclosures.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2016
Financial Instruments, Owned, at Fair Value [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The financial instruments recorded in the consolidated balance sheets include investments, receivables, options sold, total return swaps, accounts payable, and secured and unsecured notes payable. Due to their short-term maturities, the carrying values of receivables and accounts payable approximate their fair market values. All investments are carried at fair value in the consolidated balance sheets. The following table presents the estimated fair values of financial instruments: September 30, 2016 December 31, 2015 (Amounts in thousands) Assets Investments $ 3,554,236 $ 3,380,642 Liabilities Options sold $ 122 $ 260 Total return swaps $ 3,285 $ 11,525 Secured notes $ 140,000 $ 140,000 Unsecured note $ 150,000 $ 150,000 Investments The Company applies the fair value option to all fixed maturity and equity securities and short-term investments at the time an eligible item is first recognized. The cost of investments sold is determined on a first-in and first-out method and realized gains and losses are included in net realized investment gains (losses). See Note 4. Fair Value Option for additional information. Options Sold The Company writes covered call options through listed and over-the-counter exchanges. When the Company writes an option, an amount equal to the premium received by the Company is recorded as a liability and is subsequently adjusted to the current fair value of the option written. Premiums received from writing options that expire unexercised are treated by the Company on the expiration date as realized gains from investments. If a call option is exercised, the premium is added to the proceeds from the sale of the underlying security in determining whether the Company has realized a gain or loss. The Company, as writer of an option, bears the market risk of an unfavorable change in the price of the security underlying the written option. Liabilities for covered call options of $0.1 million and $0.3 million were included in other liabilities at September 30, 2016 and December 31, 2015 , respectively. Total Return Swaps The fair values of the total return swaps reflect the estimated amounts that, upon termination of the contracts, would be received for selling an asset or paid to transfer a liability in an orderly transaction at September 30, 2016 and December 31, 2015 based on models using inputs, such as interest rate yield curves and credit spreads, observable for substantially the full term of the contract. Secured Notes Payable The fair values of the Company’s $120 million and $20 million secured notes, classified as Level 2 in the fair value hierarchy described in Note 5. Fair Value Measurement, are estimated based on assumptions and inputs, such as the market value of underlying collateral and reset rates, for similarly termed notes that are observable in the market. The fair values of the secured notes approximate their carrying values. Unsecured Note Payable The fair value of the Company’s $150 million unsecured note, classified as Level 2 in the fair value hierarchy described in Note 5. Fair Value Measurement, is based on the unadjusted quoted price for similar notes in active markets. The fair value of the unsecured note approximates its carrying value. For additional disclosures regarding methods and assumptions used in estimating fair values, see Note 5. Fair Value Measurement.

Fair Value Option

Fair Value Option	9 Months Ended
	Sep. 30, 2016
Fair Value Option [Abstract]
Fair Value Option	Fair Value Option The Company applies the fair value option to all fixed maturity and equity securities and short-term investments at the time an eligible item is first recognized. The primary reasons for electing the fair value option were simplification and cost-benefit considerations as well as the expansion of the use of fair value measurement by the Company consistent with the long-term measurement objectives of the FASB for accounting for financial instruments. Gains and losses due to changes in fair value for items measured at fair value pursuant to application of the fair value option are included in net realized investment gains (losses) in the Company’s consolidated statements of operations, while interest and dividend income on investment holdings are recognized on an accrual basis at each measurement date and are included in net investment income in the Company’s consolidated statements of operations. The following table presents gains (losses) due to changes in fair value of investments that are measured at fair value pursuant to application of the fair value option: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Amounts in thousands) Fixed maturity securities $ (19,521 ) $ (1,602 ) $ 20,913 $ (30,609 ) Equity securities (2,143 ) (16,938 ) 13,430 (34,234 ) Short-term investments 532 2 184 638 Total $ (21,132 ) $ (18,538 ) $ 34,527 $ (64,205 )

Fair Value Measurement

Fair Value Measurement	9 Months Ended
	Sep. 30, 2016
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Fair Value Measurement	Fair Value Measurement The Company employs a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The fair value of a financial instrument is the amount 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 using the exit price. Accordingly, when market observable data are not readily available, the Company’s own assumptions are used to reflect those that market participants would be presumed to use in pricing the asset or liability at the measurement date. Assets and liabilities recorded at fair value on the consolidated balance sheets are categorized based on the level of judgment associated with inputs used to measure their fair values and the level of market price observability, as follows: Level 1 Unadjusted quoted prices are available in active markets for identical assets or liabilities as of the reporting date. Level 2 Pricing inputs are other than quoted prices in active markets, which are based on the following: • Quoted prices for similar assets or liabilities in active markets; • Quoted prices for identical or similar assets or liabilities in non-active markets; or • Either directly or indirectly observable inputs as of the reporting date. Level 3 Pricing inputs are unobservable and significant to the overall fair value measurement, and the determination of fair value requires significant management judgment or estimation. In certain cases, inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy within which the fair value measurement in its entirety falls has been determined based on the lowest level input that is significant to the fair value measurement in its entirety. Thus, a Level 3 fair value measurement may include inputs that are observable (Level 1 or Level 2) and unobservable (Level 3). The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and consideration of factors specific to the asset or liability. The Company uses prices and inputs that are current as of the measurement date, including during periods of market disruption. In periods of market disruption, the ability to observe prices and inputs may be reduced for many instruments. This condition could cause an instrument to be reclassified from Level 1 to Level 2, or from Level 2 to Level 3. The Company recognizes transfers between levels at either the actual date of the event or a change in circumstances that caused the transfer. Summary of Significant Valuation Techniques for Financial Assets and Financial Liabilities The Company’s fair value measurements are based on the market approach, which utilizes market transaction data for the same or similar instruments. The Company obtained unadjusted fair values on 99.7% of its portfolio from an independent pricing service. For 0.3% of its portfolio, classified as Level 3, the Company obtained specific unadjusted broker quotes based on net fund value and, to a lesser extent, unobservable inputs from at least one knowledgeable outside security broker to determine the fair value as of September 30, 2016 . Level 1 Measurements - Fair values of financial assets and financial liabilities are obtained from an independent pricing service, and are based on unadjusted quoted prices for identical assets or liabilities in active markets. Additional pricing services and closing exchange values are used as a comparison to ensure that reasonable fair values are used in pricing the investment portfolio. U.S. government bonds and agencies/Short-term bonds : Valued using unadjusted quoted market prices for identical assets in active markets. Common stock : Comprised of actively traded, exchange listed U.S. and international equity securities and valued based on unadjusted quoted prices for identical assets in active markets. Money market instruments : Valued based on unadjusted quoted prices for identical assets in active markets. Options sold/Purchased options : Comprised of free-standing exchange listed derivatives that are actively traded and valued based on unadjusted quoted prices for identical instruments in active markets. Level 2 Measurements - Fair values of financial assets and financial liabilities are obtained from an independent pricing service or outside brokers, and are based on prices for similar assets or liabilities in active markets or valuation models whose inputs are observable, directly or indirectly, for substantially the full term of the asset or liability. Additional pricing services are used as a comparison to ensure reliable fair values are used in pricing the investment portfolio. Municipal securities : Valued based on models or matrices using inputs such as quoted prices for identical or similar assets in active markets. Mortgage-backed securities : Comprised of securities that are collateralized by residential and commercial mortgage loans valued based on models or matrices using multiple observable inputs, such as benchmark yields, reported trades and broker/dealer quotes, for identical or similar assets in active markets. Corporate securities/Short-term bonds : Valued based on a multi-dimensional model using multiple observable inputs, such as benchmark yields, reported trades, broker/dealer quotes and issue spreads, for identical or similar assets in active markets. Non-redeemable preferred stock : Valued based on observable inputs, such as underlying and common stock of same issuer and appropriate spread over a comparable U.S. Treasury security, for identical or similar assets in active markets. Total return swaps : Valued based on multi-dimensional models using inputs such as interest rate yield curves, underlying debt/credit instruments and the appropriate benchmark spread for similar assets in active markets, observable for substantially the full term of the contract. Collateralized loan obligations : Valued based on underlying debt instruments and the appropriate benchmark spread for similar assets in active markets. Other asset-backed securities : Comprised of securities that are collateralized by non-mortgage assets, such as automobile loans, valued based on models or matrices using multiple observable inputs, such as benchmark yields, reported trades and broker/dealer quotes, for identical or similar assets in active markets. Secured notes payable : Valued based on underlying collateral and reset rates for similarly termed notes that are observable in the market. Unsecured notes payable : Valued based on the unadjusted quoted price for similar notes in active markets. Level 3 Measurements - Fair values of financial assets are based on inputs that are both unobservable and significant to the overall fair value measurement, including any items in which the evaluated prices obtained elsewhere were deemed to be of a distressed trading level. Collateralized debt obligations/Private equity funds : Valued based on underlying debt/credit instruments and the appropriate benchmark spread for similar assets in active markets taking into consideration unobservable inputs related to liquidity assumptions. The Company’s financial instruments at fair value are reflected in the consolidated balance sheets on a trade-date basis. Related unrealized gains or losses are recognized in net realized investment (losses) gains in the consolidated statements of operations. Fair value measurements are not adjusted for transaction costs. The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis, and indicate the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair values: September 30, 2016 Level 1 Level 2 Level 3 Total (Amounts in thousands) Assets Fixed maturity securities: U.S. government bonds and agencies $ 12,862 $ — $ — $ 12,862 Municipal securities — 2,586,211 — 2,586,211 Mortgage-backed securities — 41,101 — 41,101 Corporate securities — 211,592 — 211,592 Collateralized loan obligations — 82,521 — 82,521 Other asset-backed securities — 38,640 — 38,640 Equity securities: Common stock 331,842 — — 331,842 Non-redeemable preferred stock — 33,080 — 33,080 Private equity funds — — 9,536 9,536 Short-term investments: Short-term bonds 70,405 20,107 — 90,512 Money market instruments 116,339 — — 116,339 Total assets at fair value $ 531,448 $ 3,013,252 $ 9,536 $ 3,554,236 Liabilities Notes payable: Secured notes $ — $ 140,000 $ — $ 140,000 Unsecured notes — 150,000 — 150,000 Other liabilities: Total return swaps — 3,285 — 3,285 Options sold 122 — — 122 Total liabilities at fair value $ 122 $ 293,285 $ — $ 293,407 December 31, 2015 Level 1 Level 2 Level 3 Total (Amounts in thousands) Assets Fixed maturity securities: U.S. government bonds and agencies $ 22,507 $ — $ — $ 22,507 Municipal securities — 2,505,040 — 2,505,040 Mortgage-backed securities — 49,838 — 49,838 Corporate securities — 243,372 — 243,372 Collateralized loan obligations — 50,548 — 50,548 Other asset-backed securities — 8,698 — 8,698 Equity securities: Common stock 280,263 — — 280,263 Non-redeemable preferred stock — 24,668 — 24,668 Private equity funds — — 10,431 10,431 Short-term investments: Short-term bonds 69,991 9,850 — 79,841 Money market instruments 105,436 — — 105,436 Total assets at fair value $ 478,197 $ 2,892,014 $ 10,431 $ 3,380,642 Liabilities Notes payable: Secured notes $ — $ 140,000 $ — $ 140,000 Unsecured notes — 150,000 — 150,000 Other liabilities: Total return swaps — 11,525 — 11,525 Options sold 260 — — 260 Total liabilities at fair value $ 260 $ 301,525 $ — $ 301,785 The following table presents a summary of changes in fair value of Level 3 financial assets and financial liabilities: Three Months Ended September 30, 2016 2015 Private Equity Funds Private Equity (Amounts in thousands) Beginning balance $ 8,972 $ 13,745 Realized gains (losses) included in earnings 564 (2,049 ) Settlements — — Ending balance $ 9,536 $ 11,696 Amount of total gains (losses) for the period included in earnings attributable to assets still held at September 30 $ 564 $ (2,049 ) Nine Months Ended September 30, 2016 2015 Private Equity Funds Private Equity (Amounts in thousands) Beginning balance $ 10,431 $ 11,719 Realized losses included in earnings (895 ) (2,910 ) Reclassification from other assets — 2,911 Settlements — (24 ) Ending balance $ 9,536 $ 11,696 Amount of total losses for the period included in earnings attributable to assets still held at September 30 $ (895 ) $ (2,910 ) There were no transfers between Levels 1, 2, and 3 of the fair value hierarchy during the nine months ended September 30, 2016 and 2015 . At September 30, 2016 , the Company did not have any nonrecurring fair value measurements of nonfinancial assets or nonfinancial liabilities.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2016
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The Company is exposed to certain risks relating to its ongoing business operations. The primary risk managed by using derivative instruments is equity price risk. Equity contracts (options sold) on various equity securities are intended to manage the price risk associated with forecasted purchases or sales of such securities. The Company also enters into derivative contracts to enhance returns on its investment portfolio. On February 13, 2014 , Fannette Funding LLC ("FFL"), a special purpose investment vehicle formed and consolidated by the Company, entered into a total return swap agreement with Citibank. Under the total return swap agreement, FFL receives the income equivalent on underlying obligations due to Citibank and pays to Citibank interest on the outstanding notional amount of the underlying obligations. The total return swap is secured by approximately $30 million of U.S. Treasuries as collateral, which are included in short-term investments on the consolidated balance sheets. The Company paid interest equal to LIBOR plus 145 basis points on approximately $104 million and $95 million of underlying obligations as of September 30, 2016 and December 31, 2015 , respectively. The agreement had an initial term of one year, subject to annual renewal, and was renewed for an additional one -year term expiring February 13, 2017. On August 9, 2013 , Animas Funding LLC ("AFL"), a special purpose investment vehicle formed and consolidated by the Company, entered into a three -year total return swap agreement with Citibank, which has been renewed for an additional three -year term through August 9, 2019. Under the total return swap agreement, AFL receives the income equivalent on underlying obligations due to Citibank and pays to Citibank interest on the outstanding notional amount of the underlying obligations. The total return swap is secured by approximately $40 million of U.S. Treasuries as collateral, which are included in short-term investments on the consolidated balance sheets. The Company paid interest equal to LIBOR plus 135 basis points on approximately $144 million and $124 million of underlying obligations as of September 30, 2016 and December 31, 2015 , respectively. Fair value amounts, and gains (losses) on derivative instruments The following tables present the location and amounts of derivative fair values in the consolidated balance sheets and derivative gains (losses) in the consolidated statements of operations: Asset Derivatives Liability Derivatives September 30, 2016 December 31, 2015 September 30, 2016 December 31, 2015 (Amounts in thousands) Total return swaps - Other liabilities $ — $ — $ 3,285 $ 11,525 Options sold - Other liabilities — — 122 260 Total derivatives $ — $ — $ 3,407 $ 11,785 Gains (Losses) Recognized in Income Gains (Losses) Recognized in Income Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Amounts in thousands) Total return swaps - Net realized investment gains (losses) $ 4,172 $ (4,422 ) $ 7,915 $ (710 ) Options sold - Net realized investment gains 1,030 695 3,324 2,219 Total $ 5,202 $ (3,727 ) $ 11,239 $ 1,509 Most options sold consist of covered calls. The Company writes covered calls on underlying equity positions held as an enhanced income strategy that is permitted for the Company’s insurance subsidiaries under statutory regulations. The Company manages the risk associated with covered calls through strict capital limitations and asset diversification throughout various industries. For additional disclosures regarding options sold, see Note 5. Fair Value Measurement.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill There were no changes in the carrying amount of goodwill during the periods presented. Goodwill is reviewed annually for impairment and more frequently if potential impairment indicators exist. No impairment indicators were identified during the periods presented. Other Intangible Assets The following table presents the components of other intangible assets: Gross Carrying Amount Accumulated Amortization Net Carrying Amount Useful Lives (Amounts in thousands) (in years) As of September 30, 2016: Customer relationships $ 52,430 $ (38,081 ) $ 14,349 11 Trade names 15,400 (4,973 ) 10,427 24 Technology 4,300 (3,332 ) 968 10 Insurance license 1,400 — 1,400 Indefinite Total other intangible assets, net $ 73,530 $ (46,386 ) $ 27,144 As of December 31, 2015: Customer relationships $ 52,430 $ (34,327 ) $ 18,103 11 Trade names 15,400 (4,491 ) 10,909 24 Technology 4,300 (3,010 ) 1,290 10 Insurance license 1,400 — 1,400 Indefinite Total other intangible assets, net $ 73,530 $ (41,828 ) $ 31,702 Other intangible assets are reviewed annually for impairment and more frequently if potential impairment indicators exist. No impairment indicators were identified during the periods presented. Other intangible assets with definite useful lives are amortized on a straight-line basis over their useful lives. Other intangible assets amortization expense was $1.5 million for each of the three month periods ended September 30, 2016 and 2015, and $4.6 million and $4.5 million for the nine month periods ended September 30, 2016 and 2015, respectively. The following table presents the estimated future amortization expense related to other intangible assets as of September 30, 2016 : Year Amortization Expense (Amounts in thousands) Remainder of 2016 $ 1,519 2017 5,349 2018 5,335 2019 4,906 2020 758 Thereafter 7,877 Total $ 25,744

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2016
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Share-Based Compensation	Share-Based Compensation Share-based compensation expense for all share-based payment awards granted or modified is based on the estimated grant-date fair value. The Company recognizes these compensation costs on a straight-line basis over the requisite service period of the award. As of September 30, 2016 , all outstanding stock options have a term of ten years from the date of grant and become exercisable in four equal installments on the first through fourth anniversaries of the grant date. The fair value of stock option awards is estimated using the Black-Scholes option pricing model with the grant-date assumptions and weighted-average fair values. In February 2015, the Company's Board of Directors adopted the 2015 Incentive Award Plan (the "2015 Plan"), replacing the 2005 Equity Incentive Plan (the "2005 Plan") which expired in January 2015. The 2015 Plan was approved at the Company's Annual Meeting of Shareholders in May 2015. A maximum of 4,900,000 shares of common stock are authorized for issuance under the 2015 Plan upon exercise of stock options, stock appreciation rights and other awards, or upon vesting of restricted stock units ("RSUs") or deferred stock awards. As of September 30, 2016 , 189,000 RSUs were outstanding, and 4,711,000 shares of common stock were available for future issuances under the 2015 Plan. As of September 30, 2016 , 82,000 RSUs and 108,000 stock options were outstanding under the 2005 Plan. The Compensation Committee of the Company’s Board of Directors granted RSU awards to the Company’s senior management and key employees which will vest based upon the Company's performance during three-year performance periods ending on December 31, 2017 and 2018 for RSU awards granted under the 2015 Plan, and ending on December 31, 2016 for RSU awards granted under the 2005 Plan: Grant Year 2016 2015 2014 Three-year performance period ending December 31, 2018 2017 2016 Vesting shares, target (net of forfeited) 93,250 95,750 82,000 Vesting shares, maximum (net of forfeited) 174,844 179,531 153,750 The RSUs vest at the end of a three -year performance period beginning with the year of the grant, and then only if, and to the extent that, the Company’s performance during the performance period achieves the threshold established by the Compensation Committee of the Company’s Board of Directors. Performance thresholds are based on the Company’s cumulative underwriting income, annual underwriting income, and net earned premium growth. In February 2016, 88,074 shares of common stock, net of 58,822 shares withheld for payroll taxes, were issued upon the vesting of 146,896 RSUs awarded in 2013 resulting from the attainment of performance goals above the target threshold during the three-year performance period ended December 31, 2015. During the nine month period ended September 30, 2016 , 2,500 , 3,500 and 3,500 target RSUs granted in 2016, 2015 and 2014, respectively, were forfeited because the recipients were no longer employed by the Company. The fair value of each RSU grant was determined based on the market price of the Company's common stock on the grant date. Compensation cost is recognized based on management’s best estimate that performance goals will be achieved. If such goals are not met, no compensation cost will be recognized and any recognized compensation cost will be reversed. No stock options were awarded during the nine month period ended September 30, 2016 .

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Income Taxes	Income Taxes For financial statement purposes, the Company recognizes tax benefits related to positions taken, or expected to be taken, on a tax return only if the positions are "more-likely-than-not" sustainable. Once this threshold has been met, the Company’s measurement of its expected tax benefits is recognized in its financial statements. There was a $0.6 million increase to the total amount of unrecognized tax benefit related to tax uncertainties during the nine months ended September 30, 2016 . The increase was the result of tax positions taken regarding state tax apportionment issues based on management’s best judgment given the facts, circumstances, and information available at the reporting date. The Company does not expect any changes in such unrecognized tax benefits to have a significant impact on its consolidated financial statements within the next 12 months. The Company and its subsidiaries file income tax returns with the Internal Revenue Service and the taxing authorities of various states. Tax years that remain subject to examination by major taxing jurisdictions are 2013 through 2015 for federal taxes, and 2003 through 2015 for California state taxes. The Company is currently under examination by the California Franchise Tax Board ("FTB") for tax years 2003 through 2013. The FTB issued Notices of Proposed Assessments to the Company for tax years 2003 through 2010, which the Company formally protested. The proposed adjustments for tax years 2003 through 2006 were affirmed following an administrative protest process with the FTB examination. The Company is in settlement discussions with the FTB. If a reasonable settlement is not reached, the Company intends to pursue other options, including a formal hearing with the State Board of Equalization or litigation in superior court. Management believes that the resolution of these examinations and assessments will not have a material impact on the Company's consolidated financial statements. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial reporting basis and the respective tax basis of the Company’s assets and liabilities, and expected benefits of utilizing net operating loss, capital loss, and tax-credit carryforwards. The Company assesses the likelihood that its deferred tax assets will be realized and, to the extent management does not believe these assets are more likely than not to be realized, a valuation allowance is established. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates or laws is recognized in earnings in the period that includes the enactment date. At September 30, 2016 , the Company’s deferred income taxes were in a net asset position, which included a combination of ordinary and capital deferred tax benefits. In assessing the Company’s ability to realize deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon generating sufficient taxable income of the appropriate character within the carryback and carryforward periods available under the tax law. Management considers the reversal of deferred tax liabilities, projected future taxable income of an appropriate nature, and tax-planning strategies in making this assessment. The Company believes that through the use of prudent tax planning strategies and the generation of capital gains, sufficient income will be realized in order to maximize the full benefits of its deferred tax assets. Although realization is not assured, management believes that it is more likely than not that the Company’s deferred tax assets will be realized.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies The Company is, from time to time, named as a defendant in various lawsuits or regulatory actions incidental to its insurance business. The majority of lawsuits brought against the Company relate to insurance claims that arise in the normal course of business and are reserved for through the reserving process. For a discussion of the Company’s reserving methods, see the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 . In March 2006, the California DOI issued an Amended Notice of Non-Compliance to a Notice of Non-Compliance originally issued in February 2004 (as amended, the "2004 NNC") alleging that the Company charged rates in violation of the California Insurance Code, willfully permitted its agents to charge broker fees in violation of California law, and willfully misrepresented the actual price insurance consumers could expect to pay for insurance by the amount of a fee charged by the consumer's insurance broker. The California DOI sought to impose a fine for each policy on which the Company allegedly permitted an agent to charge a broker fee, to impose a penalty for each policy on which the Company allegedly used a misleading advertisement, and to suspend certificates of authority for a period of one year. In January 2012, the administrative law judge bifurcated the 2004 NNC between (a) the California DOI’s order to show cause (the "OSC"), in which the California DOI asserts the false advertising allegations and accusation, and (b) the California DOI’s notice of noncompliance (the "NNC"), in which the California DOI asserts the unlawful rate allegations. In February 2012, the administrative law judge ("ALJ") submitted a proposed decision dismissing the NNC, but the Commissioner rejected the ALJ’s proposed decision. The Company challenged the rejection in Los Angeles Superior Court in April 2012, and the Commissioner responded with a demurrer. Following a hearing, the Superior Court sustained the Commissioner’s demurrer, based on the Company’s failure to exhaust its administrative remedies, and the Company appealed. The Court of Appeal affirmed the Superior Court's ruling that the Company was required to exhaust its administrative remedies, but expressly preserved for later appeal the legal basis for the ALJ’s dismissal: violation of Mercury’s due process rights. Following an evidentiary hearing in April 2013, post-hearing briefs, and an unsuccessful mediation, the ALJ closed the evidentiary record on April 30, 2014. Although a proposed decision was to be submitted to the Commissioner on or before June 30, 2014, after which the Commissioner would have 100 days to accept, reject or modify the proposed decision, the proposed decision was submitted on December 8, 2014. On January 7, 2015, the Commissioner adopted the ALJ’s proposed decision, which became the Commissioner’s adopted order (the "Order"). The decision and Order found that from the period July 1, 1996, through 2006, the Company’s "brokers" were actually operating as "de facto agents" and that the charging of "broker fees" by these producers constituted the charging of "premium" in excess of the Company's approved rates, and assessed a civil penalty in the amount of $27.6 million against the Company. On February 9, 2015, the Company filed a Writ of Administrative Mandamus and Complaint for Declaratory Relief (the "Writ") in the Orange County Superior Court seeking, among other things, to require the Commissioner to vacate the Order, to stay the Order while the Superior Court action is pending, and to judicially declare as invalid the Commissioner’s interpretation of certain provisions of the California Insurance Code. Subsequent to the filing of the Writ, a consumer group petitioned and was granted the right to intervene in the Superior Court action. The court did not order a stay, and the $27.6 million assessed penalty was accrued in the fourth quarter of 2014 and paid in March 2015. The Company filed an amended Writ on September 11, 2015, adding an explicit request for a refund of the penalty, with interest. On August 12, 2016, the Court issued its ruling, granting the Writ and vacating the Commissioner’s Order. The Court found that the Commissioner and the Department did commit procedural due process violations in connection with the DOI’s rule-making efforts, but declined to vacate the Order on that specific ground. The principal findings of the Court were that (a) the "broker fees" at issue were not premium and the charging of such fees did not result in any violation of the Insurance Code rate regulation provisions, (b) the imposition of the $27.6 million penalty violated Mercury's right to fair notice and due process, and (c) there was an unreasonable delay by the Department in issuing the 2004 NNC which resulted in a "manifest injustice" to the Company. The case is expected to be remanded back to the Commissioner to refund the $27.6 million assessed penalty, plus interest, and to issue a new order consistent with the Court’s decision. The Company has not yet recognized the vacation of the Commissioner’s Order and its $27.6 million penalty, plus any related interest, as the Superior Court's decision is subject to appeal. The Company has also accrued a liability for the estimated cost to continue to defend itself in the false advertising OSC. Based upon its understanding of the facts, the California Insurance Code and the Superior Court's recent decision on the alleged unlawful rate portion of the NNC, the Company does not expect that the ultimate resolution of the false advertising OSC will be material to its financial position. The Company also establishes reserves for non-insurance claims related lawsuits, regulatory actions, and other contingencies when the Company believes a loss is probable and is able to estimate its potential exposure. For loss contingencies believed to be reasonably possible, the Company also discloses the nature of the loss contingency and an estimate of the possible loss, range of loss, or a statement that such an estimate cannot be made. While actual losses may differ from the amounts recorded and the ultimate outcome of the Company’s pending actions is generally not yet determinable, the Company does not believe that the ultimate resolution of currently pending legal or regulatory proceedings, either individually or in the aggregate, will have a material adverse effect on its financial condition, results of operations, or cash flows. In all cases, the Company vigorously defends itself unless a reasonable settlement appears appropriate. For a discussion of legal matters, see the Company’s Annual Report on Form 10-K for the year ended December 31, 2015.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Segment Information	Segment Information The Company is primarily engaged in writing personal automobile insurance and provides related property and casualty insurance products to its customers through 14 subsidiaries in 11 states, principally in California. The Company has one reportable business segment - the Property and Casualty business segment. Property and Casualty Lines The Property and Casualty business segment offers several insurance products to the Company’s individual customers and small business customers. These insurance products are: private passenger automobile, which is the Company’s primary business, and related insurance products such as homeowners, commercial automobile and commercial property. The related insurance products are primarily sold to the Company’s individual customers and small business customers, which increases retention of the Company’s private personal automobile client base. The insurance products comprising the Property and Casualty business segment are sold through the same distribution channels, mainly through independent and 100% owned insurance agents, and go through a similar underwriting process. The Company’s Chief Operating Decision Maker evaluates operating results based on pre-tax underwriting results which is calculated as net premiums earned less (i) losses and loss adjustment expenses; and (ii) underwriting expenses (policy acquisition costs and other operating expenses). Expenses are allocated based on certain assumptions that are primarily related to premiums and losses. The Company’s net investment income, net realized investment gains (losses), other income, and interest expense are excluded in evaluating pre-tax underwriting profit. The Company does not allocate its assets, including investments, or income taxes in evaluating pre-tax underwriting profit. Other Lines The Other business segment represents net premiums written and earned from an operating segment that does not meet the quantitative thresholds required to be considered a reportable segment. This operating segment offers automobile mechanical breakdown warranties which are primarily sold through automobile dealerships and credit unions. The following tables present the Company's operating results by reportable segment: Three Months Ended September 30, 2016 September 30, 2015 Property & Casualty Lines Other Total Property & Casualty Lines Other Total (Amounts in millions) Net premiums earned $ 780.6 $ 10.3 $ 790.9 $ 732.9 $ 12.6 $ 745.5 Less: Losses and loss adjustment expenses 570.8 5.5 576.3 538.6 7.1 545.7 Underwriting expenses 194.8 4.5 199.3 188.6 5.1 193.7 Underwriting gain 15.0 0.3 15.3 5.7 0.4 6.1 Investment income 30.3 30.9 Net realized investment losses (15.5 ) (26.3 ) Other income 2.4 2.3 Interest expense (0.9 ) (0.8 ) Pre-tax income $ 31.6 $ 12.2 Net income $ 26.9 $ 15.3 Nine Months Ended September 30, 2016 September 30, 2015 Property & Casualty Lines Other Total Property & Casualty Lines Other Total (Amounts in millions) Net premiums earned $ 2,305.0 $ 32.3 $ 2,337.3 $ 2,158.6 $ 39.2 $ 2,197.8 Less: Losses and loss adjustment expenses 1,748.2 17.3 1,765.5 1,559.5 21.8 1,581.3 Underwriting expenses 586.1 13.6 599.7 577.4 15.5 592.9 Underwriting gain (29.3 ) 1.4 (27.9 ) 21.7 1.9 23.6 Investment income 91.4 94.1 Net realized investment gains (losses) 55.0 (75.6 ) Other income 6.4 6.8 Interest expense (2.9 ) (2.3 ) Pre-tax income $ 122.0 $ 46.6 Net income $ 99.1 $ 51.1 The following tables present the Company’s net premiums earned and direct premiums written by line of insurance business: Three Months Ended September 30, 2016 September 30, 2015 Property & Casualty Lines Other Total Property & Casualty Lines Other Total (Amounts in millions) Private passenger automobile $ 614.0 $ — $ 614.0 $ 581.3 $ — $ 581.3 Homeowners 105.5 — 105.5 95.8 — 95.8 Commercial automobile 41.2 — 41.2 37.0 — 37.0 Other 19.9 10.3 30.2 18.8 12.6 31.4 Net premiums earned $ 780.6 $ 10.3 $ 790.9 $ 732.9 $ 12.6 745.5 Private passenger automobile $ 630.1 $ — $ 630.1 $ 609.0 $ — $ 609.0 Homeowners 116.0 — 116.0 106.6 — 106.6 Commercial automobile 41.9 — 41.9 40.1 — 40.1 Other 22.4 6.6 29.0 22.3 7.4 29.7 Direct premiums written $ 810.4 $ 6.6 $ 817.0 $ 778.0 $ 7.4 $ 785.4 Nine Months Ended September 30, 2016 September 30, 2015 Property & Casualty Lines Other Total Property & Casualty Lines Other Total (Amounts in millions) Private passenger automobile $ 1,820.1 $ — $ 1,820.1 $ 1,716.0 $ — $ 1,716.0 Homeowners 307.0 — 307.0 281.6 — 281.6 Commercial automobile 119.8 — 119.8 106.3 — 106.3 Other 58.1 32.3 90.4 54.7 39.2 93.9 Net premiums earned $ 2,305.0 $ 32.3 $ 2,337.3 $ 2,158.6 $ 39.2 2,197.8 Private passenger automobile $ 1,857.3 $ — $ 1,857.3 $ 1,763.1 $ — $ 1,763.1 Homeowners 331.4 — 331.4 300.8 — 300.8 Commercial automobile 125.2 — 125.2 114.8 — 114.8 Other 66.3 20.9 87.2 62.6 22.8 85.4 Direct premiums written $ 2,380.2 $ 20.9 $ 2,401.1 $ 2,241.3 $ 22.8 $ 2,264.1

Michigan and Pennsylvania Opera

Michigan and Pennsylvania Operations	9 Months Ended
	Sep. 30, 2016
Restructuring and Related Activities [Abstract]
Restructuring and Related Activities Disclosure [Text Block]	Michigan and Pennsylvania Operations The Company was unable to profitably grow its business in Michigan and Pennsylvania since it began writing insurance in in those states in 2004. Michigan and Pennsylvania combined net premiums earned were $15.4 million and $18.6 million in 2015 and 2014, respectively, and combined ratios were 137% and 130% in 2015 and 2014, respectively. During the second quarter of 2016, the Company implemented an exit plan to focus resources on other states with better opportunities for sustainable growth. On April 29, 2016, the Company filed plans to exit the states of Michigan and Pennsylvania with the respective state regulatory agencies. The plans were accepted by the regulators in both states with no objections. On May 10, 2016, the Company ceased accepting new business in those states and began sending non-renewal notices on June 24, 2016. The non-renewal effective dates were August 13, 2016 for private passenger automobile policyholders in Michigan and homeowners policyholders in Pennsylvania, and September 12, 2016 for private passenger automobile and commercial automobile policyholders in Pennsylvania. The Company expects to complete the run-off of its Michigan and Pennsylvania operations in 2017. In line with the goal of improving operating efficiencies and overall long-term profitability, during the second quarter of 2016, the Company restructured its claims operations in states outside of California resulting in a workforce reduction of approximately 100 employees. The affected employees, located primarily in the Company's New Jersey and Florida branch offices, were officially notified of their termination on April 29, 2016. As a result, during the second quarter of 2016, the Company recorded a charge, primarily in loss and loss adjustment expenses, of approximately $ 2 million for employee termination costs.

General (Policy)

General (Policy)	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation and Basis of Presentation	The consolidated financial statements include the accounts of Mercury General Corporation and its subsidiaries (referred to herein collectively as the "Company"). For the list of the Company’s subsidiaries, see Note 1 "Summary of Significant Accounting Policies" of the Notes to Consolidated Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 . The consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles ("GAAP"), which differ in some respects from those filed in reports to insurance regulatory authorities. All intercompany transactions and balances have been eliminated. The financial data of the Company included herein are unaudited. In the opinion of management, all material adjustments of a normal recurring nature have been made to present fairly the Company’s financial position at September 30, 2016 and the results of operations and cash flows for the periods presented. These statements were prepared in accordance with the instructions for interim reporting and do not contain certain information that was included in the annual financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 . Readers are urged to review the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 for more complete descriptions and discussions. Operating results and cash flows for the nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 .
Use of Estimates	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosures of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. These estimates require the Company to apply complex assumptions and judgments, and often the Company must make estimates about the effects of matters that are inherently uncertain and will likely change in subsequent periods. The most significant assumptions in the preparation of these condensed consolidated financial statements relate to reserves for losses and loss adjustment expenses. Actual results could differ from those estimates. See Note 1 "Summary of Significant Accounting Policies" of the Notes to Consolidated Financial Statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2015 .
Earnings per Share	Potentially dilutive securities representing approximately 22,000 and 74,000 shares of common stock for the three months ended September 30, 2016 and 2015 , respectively, and 29,000 and 52,000 shares of common stock for the nine months ended September 30, 2016 and 2015 , respectively, were excluded from the computation of diluted earnings per common share because their effect would have been anti-dilutive.
Deferred Policy Acquisition Costs	Deferred policy acquisition costs consist of commissions paid to outside agents, premium taxes, salaries, and certain other underwriting costs that are incremental or directly related to the successful acquisition of new and renewal insurance contracts and are amortized over the life of the related policy in proportion to premiums earned. Deferred policy acquisition costs are limited to the amount that will remain after deducting from unearned premiums and anticipated investment income, the estimated losses and loss adjustment expenses, and the servicing costs that will be incurred as premiums are earned. The Company’s deferred policy acquisition costs are further limited by excluding those costs not directly related to the successful acquisition of insurance contracts. Deferred policy acquisition cost amortization was $140.2 million and $132.9 million for the three months ended September 30, 2016 and 2015 , respectively, and $421.7 million and $401.9 million for the nine months ended September 30, 2016 and 2015 , respectively. The Company does not defer advertising expenditures but expenses them as incurred. The Company recorded net advertising expense of approximately $34 million and $39 million for the nine months ended September 30, 2016 and 2015 , respectively.
Recently Issued Accounting Standards	In August 2016, the Financial Accounting Standards Board (the "FASB") issued Accounting Standards Update ("ASU") 2016-15, "Classification of Certain Cash Receipts and Cash Payments (Topic 230)." The new guidance is intended to reduce diversity in how certain transactions are classified in the consolidated statement of cash flows. ASU 2016-15 will be effective for the Company beginning January 1, 2018. The Company is evaluating the impact that ASU 2016-15 will have on its consolidated financial statements and related disclosures. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326)." The amendments in this ASU replace the "incurred loss" methodology for recognizing credit losses with a methodology that reflects expected credit losses and requires consideration of a broader range of information including past events, current conditions and reasonable and supportable forecasts that affect the collectability of reported amounts of financial assets that are not accounted for at fair value through net income, such as loans, debt securities, trade receivables, net investment in leases, off-balance sheet credit exposures and reinsurance receivables. Under the current GAAP incurred loss methodology, recognition of the full amount of credit losses is generally delayed until the loss is probable of incurring. Current GAAP restricts the ability to record credit losses that are expected, but do not yet meet the probability threshold. ASU 2016-13 becomes effective for the Company beginning with the first quarter ending March 31, 2020. The Company is evaluating the impact that ASU 2016-13 will have on its consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU 2016-09, "Compensation - Stock Compensation (Topic 718)," which simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 becomes effective for the Company beginning January 1, 2017 and is required to be applied on a modified retrospective basis. The Company is evaluating the impact that ASU 2016-09 will have on its consolidated financial statements and related disclosures. In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)," which supersedes the guidance in Accounting Standards Codification ("ASC") 840, "Leases." ASU 2016-02 requires a lessee to recognize lease assets and lease liabilities resulting from all leases. ASU 2016-02 retains the distinction between a finance lease and an operating lease. Lessor accounting is largely unchanged from ASC 840. ASU 2016-02 becomes effective for the Company beginning January 1, 2019. However, in transition, the Company will be required to recognize and measure leases at the beginning of the earliest period (the first quarter of 2017) using a modified retrospective approach. The Company is evaluating the effect that ASU 2016-02 will have on its consolidated financial statements and related disclosures. In January 2016, the FASB issued ASU 2016-01, "Financial Instruments-Overall (Subtopic 825-10), Recognition and Measurement of Financial Assets and Financial Liabilities." The amendments in this ASU address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. ASU 2016-01: (1) requires equity investments (except those accounted for under the equity method or those that result in the consolidation of the investee) to be measured at fair value with changes in the fair value recognized in net income; (2) simplifies the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment; (3) eliminates the requirement for public business entities to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet; (4) requires the use of the exit price notion when measuring the fair value of financial instruments for disclosure purposes; (5) requires separate presentation of financial assets and financial liabilities by measurement category and form of financial asset on the balance sheet or the notes to the financial statements; and (6) clarifies that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity’s other deferred tax assets. ASU 2016-01 is effective for the Company beginning January 1, 2018. The Company does not anticipate that ASU 2016-01 will have a material impact on its consolidated financial statements and related disclosures. In May 2015, the FASB issued ASU 2015-09, "Financial Services -Insurance (Topic 944), Disclosures About Short-Duration Contracts." ASU 2015-09 requires insurance entities to provide additional disclosures related to claims liabilities. The additional disclosure requirements for the annual reports include: (1) claims development information by accident year, on a net of reinsurance basis, for the number of years for which claims incurred remain outstanding but not to exceed the most recent 10 years, and for the most recent reporting period presented, an insurer also needs to disclose the amount of total net outstanding claims for all accident years included in the claims development tables; (2) a reconciliation of claims development information and the aggregate carrying amount of the liability for unpaid claims and claim adjustment expenses; and (3) information about the claims frequency and the amount of the incurred-but-not-reported liabilities for each accident year presented. In addition, a description of the methodology used to determine the amounts disclosed is required. The roll forward of the liability for unpaid claims and claims adjustment expenses, currently required only for annual periods, will also be required for interim periods. ASU 2015-09 becomes effective for the Company beginning with the annual period ending December 31, 2016, and quarter periods beginning with the first quarter of 2017. Although the adoption of this standard will not have a material impact on its consolidated financial statements, the Company will expand the nature and extent of its insurance contracts disclosures. In February 2015, the FASB issued ASU 2015-02, "Consolidation (Topic 810), Amendments to the Consolidation Analysis" affecting the consolidation evaluation of limited partnerships and similar entities, fees paid to a decision maker or a service provider as a variable interest, and variable interests in a variable interest entity held by related parties of the reporting entities. The amendments became effective for the Company on January 1, 2016. As in previous GAAP, consolidation analysis under ASU 2015-02 contains two primary consolidation models: the voting control model and the variable interest ("VIE") model. An entity being evaluated for consolidation is required to first be subjected to the requirements of the VIE model. Only if the entity fails to meet the requirements to be consolidated under the VIE model, would the voting control consolidation model apply. The adoption of ASU 2015-02 did not have an impact on the Company's consolidated financial statements and related disclosures. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606)." ASU 2014-09 requires entities to apply a five-step model to determine the amount and timing of revenue recognition. The model specifies, among other criteria, that revenue should be recognized when an entity transfers control of goods or services to a customer in the amount to which the entity expects to be entitled. In August 2015, the FASB issued ASU 2015-14, "Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date," which deferred the effective date of ASU 2014-09 for the Company to January 1, 2018. Through the first half of 2016, the FASB issued additional ASUs on Topic 606 that do not change the core principle of the guidance in ASU 2014-09 but merely clarify certain aspects of it. The additional ASUs also become effective for the Company beginning January 1, 2018. The Company is evaluating the impact that these ASUs will have on its consolidated financial statements and related disclosures.

Fair Value of Financial Instr19

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
Financial Instruments, Owned, at Fair Value [Abstract]
Estimated Fair Values of Financial Instruments	The following table presents the estimated fair values of financial instruments: September 30, 2016 December 31, 2015 (Amounts in thousands) Assets Investments $ 3,554,236 $ 3,380,642 Liabilities Options sold $ 122 $ 260 Total return swaps $ 3,285 $ 11,525 Secured notes $ 140,000 $ 140,000 Unsecured note $ 150,000 $ 150,000

Fair Value Option (Tables)

Fair Value Option (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Option [Abstract]
Gains And Losses Due To Changes In Fair Value Of Investments	The following table presents gains (losses) due to changes in fair value of investments that are measured at fair value pursuant to application of the fair value option: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Amounts in thousands) Fixed maturity securities $ (19,521 ) $ (1,602 ) $ 20,913 $ (30,609 ) Equity securities (2,143 ) (16,938 ) 13,430 (34,234 ) Short-term investments 532 2 184 638 Total $ (21,132 ) $ (18,538 ) $ 34,527 $ (64,205 )

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2016
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Valuation Techniques	The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis, and indicate the fair value hierarchy of the valuation techniques utilized by the Company to determine such fair values: September 30, 2016 Level 1 Level 2 Level 3 Total (Amounts in thousands) Assets Fixed maturity securities: U.S. government bonds and agencies $ 12,862 $ — $ — $ 12,862 Municipal securities — 2,586,211 — 2,586,211 Mortgage-backed securities — 41,101 — 41,101 Corporate securities — 211,592 — 211,592 Collateralized loan obligations — 82,521 — 82,521 Other asset-backed securities — 38,640 — 38,640 Equity securities: Common stock 331,842 — — 331,842 Non-redeemable preferred stock — 33,080 — 33,080 Private equity funds — — 9,536 9,536 Short-term investments: Short-term bonds 70,405 20,107 — 90,512 Money market instruments 116,339 — — 116,339 Total assets at fair value $ 531,448 $ 3,013,252 $ 9,536 $ 3,554,236 Liabilities Notes payable: Secured notes $ — $ 140,000 $ — $ 140,000 Unsecured notes — 150,000 — 150,000 Other liabilities: Total return swaps — 3,285 — 3,285 Options sold 122 — — 122 Total liabilities at fair value $ 122 $ 293,285 $ — $ 293,407 December 31, 2015 Level 1 Level 2 Level 3 Total (Amounts in thousands) Assets Fixed maturity securities: U.S. government bonds and agencies $ 22,507 $ — $ — $ 22,507 Municipal securities — 2,505,040 — 2,505,040 Mortgage-backed securities — 49,838 — 49,838 Corporate securities — 243,372 — 243,372 Collateralized loan obligations — 50,548 — 50,548 Other asset-backed securities — 8,698 — 8,698 Equity securities: Common stock 280,263 — — 280,263 Non-redeemable preferred stock — 24,668 — 24,668 Private equity funds — — 10,431 10,431 Short-term investments: Short-term bonds 69,991 9,850 — 79,841 Money market instruments 105,436 — — 105,436 Total assets at fair value $ 478,197 $ 2,892,014 $ 10,431 $ 3,380,642 Liabilities Notes payable: Secured notes $ — $ 140,000 $ — $ 140,000 Unsecured notes — 150,000 — 150,000 Other liabilities: Total return swaps — 11,525 — 11,525 Options sold 260 — — 260 Total liabilities at fair value $ 260 $ 301,525 $ — $ 301,785
Summary Of Changes In Fair Value Of Level 3 Financial Assets And Financial Liabilities Held At Fair Value	The following table presents a summary of changes in fair value of Level 3 financial assets and financial liabilities: Three Months Ended September 30, 2016 2015 Private Equity Funds Private Equity (Amounts in thousands) Beginning balance $ 8,972 $ 13,745 Realized gains (losses) included in earnings 564 (2,049 ) Settlements — — Ending balance $ 9,536 $ 11,696 Amount of total gains (losses) for the period included in earnings attributable to assets still held at September 30 $ 564 $ (2,049 ) Nine Months Ended September 30, 2016 2015 Private Equity Funds Private Equity (Amounts in thousands) Beginning balance $ 10,431 $ 11,719 Realized losses included in earnings (895 ) (2,910 ) Reclassification from other assets — 2,911 Settlements — (24 ) Ending balance $ 9,536 $ 11,696 Amount of total losses for the period included in earnings attributable to assets still held at September 30 $ (895 ) $ (2,910 )

Derivative Financial Instrume22

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2016
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Summary Of Location And Amounts Of Derivative Fair Values In The Consolidated Balance Sheets	The following tables present the location and amounts of derivative fair values in the consolidated balance sheets and derivative gains (losses) in the consolidated statements of operations: Asset Derivatives Liability Derivatives September 30, 2016 December 31, 2015 September 30, 2016 December 31, 2015 (Amounts in thousands) Total return swaps - Other liabilities $ — $ — $ 3,285 $ 11,525 Options sold - Other liabilities — — 122 260 Total derivatives $ — $ — $ 3,407 $ 11,785
Schedule Of Derivative Gains And Losses In The Consolidated Statements Of Operations	Gains (Losses) Recognized in Income Gains (Losses) Recognized in Income Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 (Amounts in thousands) Total return swaps - Net realized investment gains (losses) $ 4,172 $ (4,422 ) $ 7,915 $ (710 ) Options sold - Net realized investment gains 1,030 695 3,324 2,219 Total $ 5,202 $ (3,727 ) $ 11,239 $ 1,509

Goodwill and Other Intangible23

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule Of Components Of Other Intangible Assets	The following table presents the components of other intangible assets: Gross Carrying Amount Accumulated Amortization Net Carrying Amount Useful Lives (Amounts in thousands) (in years) As of September 30, 2016: Customer relationships $ 52,430 $ (38,081 ) $ 14,349 11 Trade names 15,400 (4,973 ) 10,427 24 Technology 4,300 (3,332 ) 968 10 Insurance license 1,400 — 1,400 Indefinite Total other intangible assets, net $ 73,530 $ (46,386 ) $ 27,144 As of December 31, 2015: Customer relationships $ 52,430 $ (34,327 ) $ 18,103 11 Trade names 15,400 (4,491 ) 10,909 24 Technology 4,300 (3,010 ) 1,290 10 Insurance license 1,400 — 1,400 Indefinite Total other intangible assets, net $ 73,530 $ (41,828 ) $ 31,702
Schedule Of Estimated Future Amortization Expense Related To Intangible Assets	The following table presents the estimated future amortization expense related to other intangible assets as of September 30, 2016 : Year Amortization Expense (Amounts in thousands) Remainder of 2016 $ 1,519 2017 5,349 2018 5,335 2019 4,906 2020 758 Thereafter 7,877 Total $ 25,744

Share-Based Compensation (Table

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Schedule Of Performance Vesting Restricted Stock Units Granted	The Compensation Committee of the Company’s Board of Directors granted RSU awards to the Company’s senior management and key employees which will vest based upon the Company's performance during three-year performance periods ending on December 31, 2017 and 2018 for RSU awards granted under the 2015 Plan, and ending on December 31, 2016 for RSU awards granted under the 2005 Plan: Grant Year 2016 2015 2014 Three-year performance period ending December 31, 2018 2017 2016 Vesting shares, target (net of forfeited) 93,250 95,750 82,000 Vesting shares, maximum (net of forfeited) 174,844 179,531 153,750

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Reconciliation of operating results by reportable segment	The following tables present the Company's operating results by reportable segment: Three Months Ended September 30, 2016 September 30, 2015 Property & Casualty Lines Other Total Property & Casualty Lines Other Total (Amounts in millions) Net premiums earned $ 780.6 $ 10.3 $ 790.9 $ 732.9 $ 12.6 $ 745.5 Less: Losses and loss adjustment expenses 570.8 5.5 576.3 538.6 7.1 545.7 Underwriting expenses 194.8 4.5 199.3 188.6 5.1 193.7 Underwriting gain 15.0 0.3 15.3 5.7 0.4 6.1 Investment income 30.3 30.9 Net realized investment losses (15.5 ) (26.3 ) Other income 2.4 2.3 Interest expense (0.9 ) (0.8 ) Pre-tax income $ 31.6 $ 12.2 Net income $ 26.9 $ 15.3 Nine Months Ended September 30, 2016 September 30, 2015 Property & Casualty Lines Other Total Property & Casualty Lines Other Total (Amounts in millions) Net premiums earned $ 2,305.0 $ 32.3 $ 2,337.3 $ 2,158.6 $ 39.2 $ 2,197.8 Less: Losses and loss adjustment expenses 1,748.2 17.3 1,765.5 1,559.5 21.8 1,581.3 Underwriting expenses 586.1 13.6 599.7 577.4 15.5 592.9 Underwriting gain (29.3 ) 1.4 (27.9 ) 21.7 1.9 23.6 Investment income 91.4 94.1 Net realized investment gains (losses) 55.0 (75.6 ) Other income 6.4 6.8 Interest expense (2.9 ) (2.3 ) Pre-tax income $ 122.0 $ 46.6 Net income $ 99.1 $ 51.1
Schedule direct premiums attributable to segment	The following tables present the Company’s net premiums earned and direct premiums written by line of insurance business: Three Months Ended September 30, 2016 September 30, 2015 Property & Casualty Lines Other Total Property & Casualty Lines Other Total (Amounts in millions) Private passenger automobile $ 614.0 $ — $ 614.0 $ 581.3 $ — $ 581.3 Homeowners 105.5 — 105.5 95.8 — 95.8 Commercial automobile 41.2 — 41.2 37.0 — 37.0 Other 19.9 10.3 30.2 18.8 12.6 31.4 Net premiums earned $ 780.6 $ 10.3 $ 790.9 $ 732.9 $ 12.6 745.5 Private passenger automobile $ 630.1 $ — $ 630.1 $ 609.0 $ — $ 609.0 Homeowners 116.0 — 116.0 106.6 — 106.6 Commercial automobile 41.9 — 41.9 40.1 — 40.1 Other 22.4 6.6 29.0 22.3 7.4 29.7 Direct premiums written $ 810.4 $ 6.6 $ 817.0 $ 778.0 $ 7.4 $ 785.4 Nine Months Ended September 30, 2016 September 30, 2015 Property & Casualty Lines Other Total Property & Casualty Lines Other Total (Amounts in millions) Private passenger automobile $ 1,820.1 $ — $ 1,820.1 $ 1,716.0 $ — $ 1,716.0 Homeowners 307.0 — 307.0 281.6 — 281.6 Commercial automobile 119.8 — 119.8 106.3 — 106.3 Other 58.1 32.3 90.4 54.7 39.2 93.9 Net premiums earned $ 2,305.0 $ 32.3 $ 2,337.3 $ 2,158.6 $ 39.2 2,197.8 Private passenger automobile $ 1,857.3 $ — $ 1,857.3 $ 1,763.1 $ — $ 1,763.1 Homeowners 331.4 — 331.4 300.8 — 300.8 Commercial automobile 125.2 — 125.2 114.8 — 114.8 Other 66.3 20.9 87.2 62.6 22.8 85.4 Direct premiums written $ 2,380.2 $ 20.9 $ 2,401.1 $ 2,241.3 $ 22.8 $ 2,264.1

General (Details)

General (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Potentially dilutive securities (in shares)	22	74	29	52
Deferred policy acquisition cost amortization	$ 140,203	$ 132,881	$ 421,685	$ 401,868
Advertising expenses			$ 34,000	$ 39,000

Fair Value of Financial Instr27

Fair Value of Financial Instruments (Narrative) (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Liabilities	$ 293,407,000	$ 301,785,000
Level 2 [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Liabilities	293,285,000	301,525,000
Level 2 [Member] | Secured Notes One [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Secured notes	120,000,000
Level 2 [Member] | Secured Notes Two [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Secured notes	20,000,000
Options Sold [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Liabilities	$ 122,000	$ 260,000

Fair Value of Financial Instr28

Fair Value of Financial Instruments (Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Liabilities
Liabilities	$ 293,407	$ 301,785
Investments [Member]
Assets
Investments	3,554,236	3,380,642
Options Sold [Member]
Liabilities
Liabilities	122	260
Total Return Swap [Member]
Liabilities
Liabilities	3,285	11,525
Borrowings [Members] | Secured Debt [Member]
Liabilities
Liabilities	140,000	140,000
Borrowings [Members] | Unsecured Debt [Member]
Liabilities
Liabilities	$ 150,000	$ 150,000

Fair Value Option (Gains And Lo

Fair Value Option (Gains And Losses Due To Changes In Fair Value Of Investments) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
(Losses) gains due to changes in fair value of investments	$ (21,132)	$ (18,538)	$ 34,527	$ (64,205)
Fixed maturity securities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
(Losses) gains due to changes in fair value of investments	(19,521)	(1,602)	20,913	(30,609)
Equity Securities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
(Losses) gains due to changes in fair value of investments	(2,143)	(16,938)	13,430	(34,234)
Short-term investments [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
(Losses) gains due to changes in fair value of investments	$ 532	$ 2	$ 184	$ 638

Fair Value Measurement (Narrati

Fair Value Measurement (Narrative) (Details)	9 Months Ended
	Sep. 30, 2016transfersbroker	Sep. 30, 2015transfers
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of portfolio of unadjusted fair values obtained	99.70%
Percentage of portfolio of specific unadjusted broker quotes obtained	0.30%
Transfers between Levels 1, 2, and 3 of the fair value hierarchy | transfers	0	0
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of knowledgeable outside security brokers consulted to determine fair value | broker	1

Fair Value Measurement (Schedul

Fair Value Measurement (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Valuation Techniques) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	$ 3,554,236	$ 3,380,642
Liabilities	293,407	301,785
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	531,448	478,197
Liabilities	122	260
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	3,013,252	2,892,014
Liabilities	293,285	301,525
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	9,536	10,431
Liabilities	0	0
Fixed maturity securities [Member] | US Treasury and Government [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	12,862	22,507
Fixed maturity securities [Member] | US States and Political Subdivisions Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	2,586,211	2,505,040
Fixed maturity securities [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	41,101	49,838
Fixed maturity securities [Member] | Corporate Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	211,592	243,372
Fixed maturity securities [Member] | Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	82,521	50,548
Fixed maturity securities [Member] | Collateralized Auto Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	38,640	8,698
Fixed maturity securities [Member] | Level 1 [Member] | US Treasury and Government [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	12,862	22,507
Fixed maturity securities [Member] | Level 1 [Member] | US States and Political Subdivisions Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 1 [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 1 [Member] | Corporate Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 1 [Member] | Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 1 [Member] | Collateralized Auto Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 2 [Member] | US Treasury and Government [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	2,586,211	2,505,040
Fixed maturity securities [Member] | Level 2 [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	41,101	49,838
Fixed maturity securities [Member] | Level 2 [Member] | Corporate Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	211,592	243,372
Fixed maturity securities [Member] | Level 2 [Member] | Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	82,521	50,548
Fixed maturity securities [Member] | Level 2 [Member] | Collateralized Auto Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	38,640	8,698
Fixed maturity securities [Member] | Level 3 [Member] | US Treasury and Government [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 3 [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 3 [Member] | Corporate Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 3 [Member] | Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Fixed maturity securities [Member] | Level 3 [Member] | Collateralized Auto Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Equity Securities [Member] | Common Stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	331,842	280,263
Equity Securities [Member] | Nonredeemable Preferred Stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	33,080	24,668
Equity Securities [Member] | Partnership Interest In Private Credit Fund [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	9,536	10,431
Equity Securities [Member] | Level 1 [Member] | Common Stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	331,842	280,263
Equity Securities [Member] | Level 1 [Member] | Nonredeemable Preferred Stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Equity Securities [Member] | Level 1 [Member] | Partnership Interest In Private Credit Fund [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Equity Securities [Member] | Level 2 [Member] | Common Stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Equity Securities [Member] | Level 2 [Member] | Nonredeemable Preferred Stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	33,080	24,668
Equity Securities [Member] | Level 2 [Member] | Partnership Interest In Private Credit Fund [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Equity Securities [Member] | Level 3 [Member] | Common Stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Equity Securities [Member] | Level 3 [Member] | Nonredeemable Preferred Stock [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Equity Securities [Member] | Level 3 [Member] | Partnership Interest In Private Credit Fund [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	9,536	10,431
Short-term Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	90,512	79,841
Short-term Investments [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	70,405	69,991
Short-term Investments [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	20,107	9,850
Short-term Investments [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Money Market Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	116,339	105,436
Money Market Funds [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	116,339	105,436
Money Market Funds [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Money Market Funds [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure, Recurring	0	0
Borrowings [Members] | Secured Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	140,000	140,000
Borrowings [Members] | Unsecured Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	150,000	150,000
Borrowings [Members] | Level 1 [Member] | Secured Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	0	0
Borrowings [Members] | Level 1 [Member] | Unsecured Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	0	0
Borrowings [Members] | Level 2 [Member] | Secured Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	140,000
Borrowings [Members] | Level 2 [Member] | Unsecured Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	150,000
Borrowings [Members] | Level 3 [Member] | Secured Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	0	0
Borrowings [Members] | Level 3 [Member] | Unsecured Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	0	0
Total Return Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	3,285	11,525
Total Return Swap [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	0	0
Total Return Swap [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	3,285	11,525
Total Return Swap [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	0	0
Equity Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	122	260
Equity Contract [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	122	260
Equity Contract [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	0	0
Equity Contract [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Liabilities	$ 0	$ 0

Fair Value Measurement (Summary

Fair Value Measurement (Summary Of Changes In Fair Value Of Level 3 Financial Assets And Financial Liabilities Held At Fair Value) (Details) - Partnership Interest In Private Credit Fund [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 8,972	$ 13,745	$ 10,431	$ 11,719
Realized gains (losses) included in earnings	564	(2,049)	(895)	(2,910)
Reclassification from other assets			0	2,911
Settlements	0	0	0	(24)
Ending Balance	9,536	11,696	9,536	11,696
The amount of total (losses) gains for the period included in earnings attributable to assets still held at September 30	$ 564	$ (2,049)	$ (895)	$ (2,910)

Derivative Financial Instrume33

Derivative Financial Instruments (Narrative) (Details) - USD ($) $ in Millions	Feb. 13, 2014	Aug. 09, 2013	Sep. 30, 2016	Dec. 31, 2015
2014 Swap [Member]
Derivative Financial Instruments [Line Items]
Swap agreement collateral			$ 30
Notional amount			$ 104	$ 95
Term of swap agreement	1 year
Renewal term	1 year
2014 Swap [Member] | LIBOR [Member]
Derivative Financial Instruments [Line Items]
Basis spread on variable rate			1.45%
2013 Swap [Member]
Derivative Financial Instruments [Line Items]
Swap agreement collateral			$ 40
Notional amount			$ 144	$ 124
Term of swap agreement		3 years	3 years
2013 Swap [Member] | LIBOR [Member]
Derivative Financial Instruments [Line Items]
Basis spread on variable rate			1.35%

Derivative Financial Instrume34

Derivative Financial Instruments (Summary Of Location And Amounts Of Derivative Fair Values In The Consolidated Balance Sheets) (Details) - Non-hedging derivatives [Member] - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Asset Derivatives	$ 0	$ 0
Total return swap	3,407	11,785
Interest rate swap agreements [Member] | Other Assets [Member]
Derivative [Line Items]
Asset Derivatives	0	0
Interest rate swap agreements [Member] | Other liabilities [Member]
Derivative [Line Items]
Total return swap	3,285	11,525
Equity contracts [Member] | Other Assets [Member]
Derivative [Line Items]
Asset Derivatives	0	0
Equity contracts [Member] | Other liabilities [Member]
Derivative [Line Items]
Total return swap	$ 122	$ 260

Derivative Financial Instrume35

Derivative Financial Instruments (Schedule Of Derivative Gains And Losses In The Consolidated Statements Of Operations) (Details) - Derivatives Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative [Line Items]
Gain Recognized in Income (Loss)	$ 5,202	$ (3,727)	$ 11,239	$ 1,509
Total Return Swap [Member] | Other revenue [Member]
Derivative [Line Items]
Gain Recognized in Income (Loss)	4,172	(4,422)	7,915	(710)
Equity contracts [Member] | Net realized investment (losses) gains [Member]
Derivative [Line Items]
Gain Recognized in Income (Loss)	$ 1,030	$ 695	$ 3,324	$ 2,219

Goodwill and Other Intangible36

Goodwill and Other Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets amortization expense	$ 1.5	$ 1.5	$ 4.6	$ 4.5

Goodwill and Other Intangible37

Goodwill and Other Intangible Assets (Schedule Of Components Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 73,530	$ 73,530
Accumulated Amortization	(46,386)	(41,828)
Total	27,144	31,702
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	52,430	52,430
Accumulated Amortization	(38,081)	(34,327)
Total	$ 14,349	$ 18,103
Useful Lives (in years)	11 years	11 years
Trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 15,400	$ 15,400
Accumulated Amortization	(4,973)	(4,491)
Total	$ 10,427	$ 10,909
Useful Lives (in years)	24 years	24 years
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,300	$ 4,300
Accumulated Amortization	(3,332)	(3,010)
Total	$ 968	$ 1,290
Useful Lives (in years)	10 years	10 years

Goodwill and Other Intangible38

Goodwill and Other Intangible Assets (Schedule of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 73,530	$ 73,530
Other intangible assets, net	27,144	31,702
Licensing Agreements [Member]
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	1,400	1,400
Other intangible assets, net	$ 1,400	$ 1,400

Goodwill and Other Intangible39

Goodwill and Other Intangible Assets (Schedule Of Estimated Future Amortization Expense Related To Intangible Assets) (Details) $ in Thousands	Sep. 30, 2016USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Remainder of 2016	$ 1,519
2,017	5,349
2,018	5,335
2,019	4,906
2,020	758
Thereafter	7,877
Total	$ 25,744

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) - shares	1 Months Ended	9 Months Ended
	Feb. 29, 2016	Sep. 30, 2016	Feb. 28, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period of restricted stock units (in years)		3 years
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued during period	88,074
Shares withheld for payroll taxes	58,822
Incentive Award Plan 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized			4,900,000
Incentive Award Plan 2015 [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		4,711,000
Two Thousand Five Plan [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		108,000
Target Restricted Stock Units, 2015 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested options forfeited		2,500
Target Restricted Stock Units, 2014 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested options forfeited		3,500
Target Restricted Stock Units, 2013 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested options forfeited		3,500
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting term (in years)		10 years
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs vested during period	146,896
Restricted Stock [Member] | Incentive Award Plan 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		189,000
Restricted Stock [Member] | Two Thousand Five Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number		82,000

Share-Based Compensation (Sched

Share-Based Compensation (Schedule Of Performance Vesting Restricted Stock Units Granted) (Details) - shares	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation, Allocation and Classification in Financial Statements [Abstract]
Three-year performance period ending December 31,	2,018	2,017	2,016
Vesting shares, target	93,250	95,750	82,000
Vesting shares, maximum	174,844	179,531	153,750

Income Taxes (Details)

Income Taxes (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016USD ($)
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Increase in unrecognized tax benefit	$ 0.6

Contingencies (Details)

Contingencies (Details) $ in Millions	Jan. 07, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Litigation settlement, expense	$ 27.6

Segment Information - Summary o

Segment Information - Summary of Operating Results by Segment (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)State	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)SubsidiaryState	Sep. 30, 2015USD ($)
Segment Reporting [Abstract]
Number of insurance companies | Subsidiary			14
Number of states in which company operates | State	11		11
Segment Reporting Information [Line Items]
Net premiums earned	$ 790,900	$ 745,500	$ 2,337,300	$ 2,197,800
Losses and loss adjustment expenses	576,316	545,692	1,765,484	1,581,306
Underwriting expenses	199,300	193,700	599,700	592,900
Underwriting gain	15,300	6,100	(27,900)	23,600
Net investment income	30,371	30,898	91,440	94,101
Net realized investment losses	(15,465)	(26,286)	54,973	(75,595)
Other	2,406	2,281	6,416	6,823
Interest Expense	(1,012)	(785)	(2,922)	(2,304)
Pre-tax income	31,625	12,267	121,994	46,637
Net income	26,930	15,270	99,126	51,074
Property and Casualty Lines [Member]
Segment Reporting Information [Line Items]
Net premiums earned	780,600	732,900	2,305,000	2,158,600
Losses and loss adjustment expenses	570,800	538,600	1,748,200	1,559,500
Underwriting expenses	194,800	188,600	586,100	577,400
Underwriting gain	15,000	5,700	(29,300)	21,700
Other Segments [Member]
Segment Reporting Information [Line Items]
Net premiums earned	10,300	12,600	32,300	39,200
Losses and loss adjustment expenses	5,500	7,100	17,300	21,800
Underwriting expenses	4,500	5,100	13,600	15,500
Underwriting gain	$ 300	$ 400	$ 1,400	$ 1,900

Segment Information - Summary45

Segment Information - Summary of Premiums Written and Earned by Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Net premiums earned	$ 790.9	$ 745.5	$ 2,337.3	$ 2,197.8
Direct Premiums Written	817	785.4	2,401.1	2,264.1
Property and Casualty, Personal Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	614	581.3	1,820.1	1,716
Direct Premiums Written	630.1	609	1,857.3	1,763.1
Property Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	105.5	95.8	307	281.6
Direct Premiums Written	116	106.6	331.4	300.8
Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	41.2	37	119.8	106.3
Direct Premiums Written	41.9	40.1	125.2	114.8
Other Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	30.2	31.4	90.4	93.9
Direct Premiums Written	29	29.7	87.2	85.4
Property and Casualty Lines [Member]
Segment Reporting Information [Line Items]
Net premiums earned	780.6	732.9	2,305	2,158.6
Direct Premiums Written	810.4	778	2,380.2	2,241.3
Property and Casualty Lines [Member] | Property and Casualty, Personal Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	614	581.3	1,820.1	1,716
Direct Premiums Written	630.1	609	1,857.3	1,763.1
Property and Casualty Lines [Member] | Property Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	105.5	95.8	307	281.6
Direct Premiums Written	116	106.6	331.4	300.8
Property and Casualty Lines [Member] | Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	41.2	37	119.8	106.3
Direct Premiums Written	41.9	40.1	125.2	114.8
Property and Casualty Lines [Member] | Other Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	19.9	18.8	58.1	54.7
Direct Premiums Written	22.4	22.3	66.3	62.6
Other Segments [Member]
Segment Reporting Information [Line Items]
Net premiums earned	10.3	12.6	32.3	39.2
Direct Premiums Written	6.6	7.4	20.9	22.8
Other Segments [Member] | Property and Casualty, Personal Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	0	0	0	0
Direct Premiums Written	0	0	0	0
Other Segments [Member] | Property Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	0	0	0	0
Direct Premiums Written	0	0	0	0
Other Segments [Member] | Property and Casualty, Commercial Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	0	0	0	0
Direct Premiums Written	0	0	0	0
Other Segments [Member] | Other Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Net premiums earned	10.3	12.6	32.3	39.2
Direct Premiums Written	$ 6.6	$ 7.4	$ 20.9	$ 22.8

Michigan and Pennsylvania Ope46

Michigan and Pennsylvania Operations (Details) $ in Millions	Apr. 29, 2016employee	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Restructuring Cost and Reserve [Line Items]
Net premiums earned		$ 790.9	$ 745.5	$ 2,337.3	$ 2,197.8
Michigan And Pennsylvania [Member]
Restructuring Cost and Reserve [Line Items]
Net premiums earned						$ 15.4	$ 18.6
Combined ratio						137.00%	130.00%
Michigan And Pennsylvania [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees impacted by workforce reduction | employee	100
Expected employee termination costs		$ 2		$ 2