Erie Indemnity (ERIE) 10-Q 26 Oct 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 13, 2017
Entity Registrant Name	ERIE INDEMNITY CO
Entity Central Index Key	922,621
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Class A
Entity Common Stock, Shares Outstanding		46,189,068
Class B
Entity Common Stock, Shares Outstanding		2,542

STATEMENTS OF OPERATIONS

STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Operating revenue
Management fee revenue, net	$ 435,214	$ 411,139	$ 1,268,591	$ 1,195,262
Service agreement revenue	7,278	7,267	21,781	21,756
Total operating revenue	442,492	418,406	1,290,372	1,217,018
Operating expenses
Commissions	248,677	232,455	720,538	676,963
Salaries and employee benefits	60,499	53,265	181,013	161,579
All other operating expenses	52,480	50,431	158,407	142,797
Total operating expenses	361,656	336,151	1,059,958	981,339
Operating income	80,836	82,255	230,414	235,679
Investment income
Net investment income	5,970	5,331	18,184	14,884
Net realized investment gains	899	718	1,539	29
Net impairment losses recognized in earnings	0	0	(182)	(345)
Equity in earnings (losses) of limited partnerships	1,537	(1,723)	1,899	(279)
Total investment income	8,406	4,326	21,440	14,289
Interest expense, net	377		800
Income before income taxes	88,865	86,581	251,054	249,968
Income tax expense	30,322	29,205	86,108	85,388
Net income	$ 58,543	$ 57,376	$ 164,946	$ 164,580
Class A
Net income per share
Common stock - basic (in dollars per share)	$ 1.26	$ 1.23	$ 3.54	$ 3.53
Common stock - diluted (in dollars per share)	$ 1.12	$ 1.09	$ 3.15	$ 3.14
Weighted average shares outstanding – Basic
Common stock - basic (in shares)	46,188,949	46,188,980	46,186,109	46,188,971
Weighted average shares outstanding – Diluted
Common stock - diluted (in shares)	52,316,876	52,411,303	52,342,450	52,442,697
Dividends declared per share
Common stock (in dollars per share)	$ 0.7825	$ 0.7300	$ 2.3475	$ 2.1900
Class B
Net income per share
Common stock - basic (in dollars per share)	189	185	531	530
Common stock - diluted (in dollars per share)	$ 189	$ 185	$ 531	$ 529
Weighted average shares outstanding – Basic
Common stock - basic (in shares)	2,542	2,542	2,542	2,542
Weighted average shares outstanding – Diluted
Common stock - diluted (in shares)	2,542	2,542	2,542	2,542
Dividends declared per share
Common stock (in dollars per share)	$ 117.375	$ 109.500	$ 352.125	$ 328.500

STATEMENTS OF COMPREHENSIVE INC

STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 58,543	$ 57,376	$ 164,946	$ 164,580
Other comprehensive income, net of tax
Change in unrealized holding (losses) gains on available-for-sale securities	(167)	355	2,446	6,846
Comprehensive income	$ 58,376	$ 57,731	$ 167,392	$ 171,426

STATEMENTS OF FINANCIAL POSITIO

STATEMENTS OF FINANCIAL POSITION - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 184,628	$ 189,072
Available-for-sale securities	65,318	56,138
Receivables from Erie Insurance Exchange and affiliates	428,500	378,540
Prepaid expenses and other current assets	35,797	30,169
Federal income taxes recoverable	0	5,260
Accrued investment income	6,435	6,337
Total current assets	720,678	665,516
Available-for-sale securities	683,948	657,153
Limited partnership investments	49,451	58,159
Fixed assets, net	75,370	69,142
Deferred income taxes, net	47,558	53,889
Note receivable from Erie Family Life Insurance Company	25,000	25,000
Other assets	29,424	20,096
Total assets	1,631,429	1,548,955
Current liabilities:
Commissions payable	236,056	210,559
Agent bonuses	93,448	114,772
Accounts payable and accrued liabilities	99,331	88,153
Dividends payable	36,441	36,441
Deferred executive compensation	12,794	19,675
Federal income taxes payable	5,331	0
Total current liabilities	483,401	469,600
Defined benefit pension plans	208,528	221,827
Employee benefit obligations	330	756
Deferred executive compensation	12,777	13,233
Long-term borrowings	49,734	24,766
Other long-term liabilities	1,509	1,863
Total liabilities	756,279	732,045
Shareholders’ equity
Additional paid-in-capital	16,470	16,300
Accumulated other comprehensive loss	(118,935)	(121,381)
Retained earnings	2,121,535	2,065,911
Total contributed capital and retained earnings	2,021,240	1,963,000
Treasury stock, at cost; 22,110,132 shares held	(1,155,396)	(1,155,846)
Deferred compensation	9,306	9,756
Total shareholders’ equity	875,150	816,910
Total liabilities and shareholders’ equity	1,631,429	1,548,955
Class A
Shareholders’ equity
Common stock	1,992	1,992
Class B
Shareholders’ equity
Common stock	$ 178	$ 178

STATEMENTS OF FINANCIAL POSITI5

STATEMENTS OF FINANCIAL POSITION (Parenthetical) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
Treasury stock (in shares)	22,110,132	22,110,132
Class A
Common stock, stated value per share (in dollars per share)	$ 0.0292	$ 0.0292
Common stock, authorized (in shares)	74,996,930	74,996,930
Common stock, issued (in shares)	68,299,200	68,299,200
Common stock, outstanding (in shares)	46,189,068	46,189,068
Class B
Common stock, stated value per share (in dollars per share)	$ 70	$ 70
Common stock, authorized (in shares)	3,070	3,070
Common stock, issued (in shares)	2,542	2,542
Common stock, outstanding (in shares)	2,542	2,542
Ratio for converting shares of Class B common stock into shares of Class A common stock (as a percent)	2400.00%	2400.00%

STATEMENTS OF CASH FLOWS

STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities
Management fee received	$ 1,225,966	$ 1,155,234
Service agreement fee received	21,781	21,756
Net investment income received	23,593	19,643
Limited partnership distributions	2,993	7,222
Decrease in reimbursements collected from affiliates	(7,335)	(11,893)
Commissions paid to agents	(597,700)	(565,490)
Agents bonuses paid	(118,862)	(110,503)
Salaries and wages paid	(128,071)	(119,991)
Pension contribution and employee benefits paid	(62,837)	(37,341)
General operating expenses paid	(167,985)	(133,729)
Income taxes paid	(70,504)	(69,357)
Interest paid	(705)
Net cash provided by operating activities	120,334	155,551
Purchase of investments:
Available-for-sale securities	(292,702)	(269,237)
Limited partnerships	(330)	(449)
Proceeds from investments:
Available-for-sale securities sales	120,418	67,415
Available-for-sale securities maturities/calls	146,434	96,851
Trading securities		5,171
Limited partnerships	7,986	12,404
Net purchase of fixed assets	(18,036)	(10,415)
Net (distributions) collections on agent loans	(4,185)	1,622
Net cash used in investing activities	(40,415)	(96,638)
Cash flows from financing activities
Dividends paid to shareholders	(109,324)	(101,989)
Net proceeds from long-term borrowings	24,961
Net cash used in financing activities	(84,363)	(101,989)
Net decrease in cash and cash equivalents	(4,444)	(43,076)
Cash and cash equivalents, beginning of period	189,072	182,889
Cash and cash equivalents, end of period	$ 184,628	$ 139,813

Nature of Operations

Nature of Operations	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Note 1. Nature of Operations Erie Indemnity Company ("Indemnity", "we", "us", "our") is a publicly held Pennsylvania business corporation that has since its incorporation in 1925 served as the attorney-in-fact for the subscribers (policyholders) at the Erie Insurance Exchange ("Exchange"). The Exchange, which also commenced business in 1925, is a Pennsylvania-domiciled reciprocal insurer that writes property and casualty insurance. We function solely as the management company and all insurance operations are performed by the Exchange. Our primary function, as attorney-in-fact, is to perform certain services for the Exchange relating to the sales, underwriting, and issuance of policies on behalf of the Exchange. This is done in accordance with a subscriber’s agreement (a limited power of attorney) executed individually by each subscriber (policyholder), which appoints us as their common attorney-in-fact to transact certain business on their behalf. Pursuant to the subscriber’s agreement and for its services as attorney-in-fact, we earn a management fee calculated as a percentage of the direct and assumed premiums written by the Exchange. The services we provide to the Exchange are related to the sales, underwriting and issuance of policies. The sales related services we provide include agent compensation and certain sales and advertising support services. Agent compensation includes scheduled commissions to agents based upon premiums written as well as additional commissions and bonuses to agents, which are earned by achieving targeted measures. The underwriting services we provide include underwriting and policy processing. The remaining services we provide include customer service and administrative support. We also provide information technology services that support all the functions listed above. By virtue of its legal structure as a reciprocal insurer, the Exchange does not have the ability to enter into contractual relationships and therefore Indemnity serves as the attorney-in-fact on behalf of the Exchange and arranges for the provision of all claims handling services, investment management services, and certain other common overhead and service department functions and serves as the common pay agent. The amounts Indemnity incurs in this capacity are reimbursed to Indemnity from the Exchange at cost. Our results of operations are tied to the growth and financial condition of the Exchange. If any events occurred that impaired the Exchange’s ability to grow or sustain its financial condition, including but not limited to reduced financial strength ratings, disruption in the independent agency relationships, significant catastrophe losses, or products not meeting customer demands, the Exchange could find it more difficult to retain its existing business and attract new business. A decline in the business of the Exchange almost certainly would have as a consequence a decline in the total premiums paid and a correspondingly adverse effect on the amount of the management fees we receive. We also have an exposure to a concentration of credit risk related to the unsecured receivables due from the Exchange for its management fee. See Note 12, "Concentrations of Credit Risk" contained within this report.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Significant Accounting Policies	Note 2. Significant Accounting Policies Basis of presentation The accompanying unaudited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the nine months ended September 30, 2017 are not necessarily indicative of the results that may be expected for the year ending December 31, 2017 . For further information, refer to the financial statements and footnotes included in our Form 10-K for the year ended December 31, 2016 as filed with the Securities and Exchange Commission on February 23, 2017 . Use of estimates The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Recently issued accounting standards In March 2017, the FASB issued ASU 2017-07, "Compensation-Retirement Benefits", which requires the service cost component of net benefit costs to be reported with other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit costs are required to be presented separately from the service cost component and outside of income from operations. This amendment also allows only the service cost component to be eligible for capitalization when applicable. The guidance is effective for interim and annual periods beginning after December 15, 2017. While the presentation of the costs within the Statements of Operations will change, we do not expect a material impact on our financial statements or related disclosures. In March 2017, the FASB issued ASU 2017-08, "Receivables-Nonrefundable Fees and Other Costs" , which shortens the amortization period for certain purchased callable debt securities held at a premium from maturity date to the earliest call date. ASU 2017-08 is effective for interim and annual reporting periods beginning after December 31, 2018. The guidance should be applied using a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. Early adoption is permitted, including adoption in an interim period. We do not expect the adoption of this guidance to have a material impact on our financial statements. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments-Credit Losses" , which requires financial assets measured at amortized cost to be presented at the net amount expected to be collected through the use of a new forward-looking expected loss model and credit losses relating to available-for-sale debt securities to be recognized through an allowance for credit losses. ASU 2016-13 is effective for interim and annual reporting periods beginning after December 15, 2019. Early adoption for interim and annual periods beginning after December 15, 2018 is permitted. We have evaluated the impact of this guidance on our invested assets. Our investments are not measured at amortized cost, which are the investments that require the use of a new expected loss model. Our available-for-sale debt securities will continue to be monitored for credit losses which would be reflected as an allowance for credit losses rather than a reduction of the carrying value of the asset. The other material financial assets subject to this guidance include our receivables from Erie Insurance Exchange and affiliates. Given the financial strength of the Exchange, demonstrated by its strong surplus position and industry ratings, it is unlikely these receivables would have significant, if any, credit loss exposure. We do not expect a material impact on our financial statements or related disclosures as a result of this guidance. In February 2016, the FASB issued ASU 2016-02, "Leases" , which requires lessees to recognize assets and liabilities arising from operating leases on the statement of financial position and to disclose key information about leasing arrangements. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Leases are required to be recognized and measured at the beginning of the earliest period presented using a modified retrospective approach. Early adoption is permitted. We expect to adopt ASU 2016-02 as of January 1, 2019 using the modified retrospective method. Under existing guidance, we recognize lease expense as a component of operating expenses in the Statements of Operations. We are in the process of evaluating our existing lease contracts to determine the impact to our financial statements and disclosures. In January 2016, the FASB issued ASU 2016-01, "Financial Instruments-Overall" . ASU 2016-01 revises the accounting related to the classification and measurement of investments in equity securities and the presentation of certain fair value changes for financial liabilities measured at fair value. ASU 2016-01 is effective for interim and annual reporting periods beginning after December 15, 2017. As of September 30, 2017, we do not own any equity security investments, therefore the adoption of this guidance would have no impact to our financial statements. We will continue to monitor our investment portfolio as we may enter into investments in equity securities; however, at this time we do not expect that recognizing the change in fair value of future equity investments through net income instead of accumulated other comprehensive income would be material. In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers" . ASU 2014-09 requires an entity to recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within that reporting period with early application permitted beginning in the first interim period in 2017. We expect to adopt the ASU 2014-09 as of January 1, 2018 under the modified retrospective method where the cumulative effect is recognized at the date of initial application. Our evaluation is ongoing and not complete. We performed an analysis in accordance with the steps identified in the new guidance around the recognition, measurement, and presentation of management fee revenue. We determined that service fee revenue is not within the scope of the new guidance. We have preliminarily concluded that adoption of this guidance will not have a material impact on our management fee revenue recognition pattern or our financial statements. We are also reviewing agreements related to the amounts we receive as reimbursements from the Exchange and its subsidiaries, such as claims-related expenses, investment and other overhead expenses. While the expenses are reimbursed to us at actual cost, we are evaluating if there is a performance obligation that would require allocation of revenue under this guidance. Additionally, we are evaluating the impact of the new disclosure requirements.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Note 3. Earnings Per Share Class A and Class B basic earnings per share and Class B diluted earnings per share are calculated under the two-class method. The two-class method allocates earnings to each class of stock based upon its dividend rights. Class B shares are convertible into Class A shares at a conversion ratio of 2,400 to 1. See Note 9, "Capital Stock". Class A diluted earnings per share are calculated under the if-converted method, which reflects the conversion of Class B shares to Class A shares. Diluted earnings per share calculations include the dilutive effect of assumed issuance of stock-based awards under compensation plans that have the option to be paid in stock using the treasury stock method. A reconciliation of the numerators and denominators used in the basic and diluted per-share computations is presented as follows for each class of common stock: Three months ended September 30, 2017 2016 (dollars in thousands, except per share data) Allocated net income (numerator) Weighted shares (denominator) Per-share amount Allocated net income (numerator) Weighted shares (denominator) Per-share amount Class A – Basic EPS: Income available to Class A stockholders $ 58,064 46,188,949 $ 1.26 $ 56,906 46,188,980 $ 1.23 Dilutive effect of stock-based awards 0 27,127 — 0 121,523 — Assumed conversion of Class B shares 479 6,100,800 — 470 6,100,800 — Class A – Diluted EPS: Income available to Class A stockholders on Class A equivalent shares $ 58,543 52,316,876 $ 1.12 $ 57,376 52,411,303 $ 1.09 Class B – Basic EPS: Income available to Class B stockholders $ 479 2,542 $ 189 $ 470 2,542 $ 185 Class B – Diluted EPS: Income available to Class B stockholders $ 479 2,542 $ 189 $ 469 2,542 $ 185 Nine months ended September 30, 2017 2016 (dollars in thousands, except per share data) Allocated net income (numerator) Weighted shares (denominator) Per-share amount Allocated net income (numerator) Weighted shares (denominator) Per-share amount Class A – Basic EPS: Income available to Class A stockholders $ 163,596 46,186,109 $ 3.54 $ 163,233 46,188,971 $ 3.53 Dilutive effect of stock-based awards 0 55,541 — 0 152,926 — Assumed conversion of Class B shares 1,350 6,100,800 — 1,347 6,100,800 — Class A – Diluted EPS: Income available to Class A stockholders on Class A equivalent shares $ 164,946 52,342,450 $ 3.15 $ 164,580 52,442,697 $ 3.14 Class B – Basic EPS: Income available to Class B stockholders $ 1,350 2,542 $ 531 $ 1,347 2,542 $ 530 Class B – Diluted EPS: Income available to Class B stockholders $ 1,350 2,542 $ 531 $ 1,346 2,542 $ 529

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value	Note 4. Fair Value Our available-for-sale and trading securities are recorded at fair value, which is the price that would be received to sell the asset in an orderly transaction between willing market participants as of the measurement date. Valuation techniques used to derive the fair value of our available-for-sale and trading securities are based upon observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources. Unobservable inputs reflect our own assumptions regarding fair market value for these securities. Although virtually all of our prices are obtained from third party sources, we also perform an internal pricing review on outliers, which include securities with price changes inconsistent with current market conditions. Financial instruments are categorized based upon the following characteristics or inputs to the valuation techniques: • Level 1 – Quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the measurement date. • Level 2 – Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. • Level 3 – Unobservable inputs for the asset or liability. Estimates of fair values for our investment portfolio are obtained primarily from a nationally recognized pricing service. Our Level 1 category includes those securities valued using an exchange traded price provided by the pricing service. The methodologies used by the pricing service that support a Level 2 classification of a financial instrument include multiple verifiable, observable inputs including benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data. Pricing service valuations for Level 3 securities are based upon proprietary models and are used when observable inputs are not available or in illiquid markets. In limited circumstances we adjust the price received from the pricing service when, in our judgment, a better reflection of fair value is available based upon corroborating information and our knowledge and monitoring of market conditions such as a disparity in price of comparable securities and/or non-binding broker quotes. In other circumstances, certain securities are internally priced because prices are not provided by the pricing service. We perform continuous reviews of the prices obtained from the pricing service. This includes evaluating the methodology and inputs used by the pricing service to ensure that we determine the proper classification level of the financial instrument. Price variances, including large periodic changes, are investigated and corroborated by market data. We have reviewed the pricing methodologies of our pricing service as well as other observable inputs, such as data, and transaction volumes and believe that their prices adequately consider market activity in determining fair value. Our review process continues to evolve based upon accounting guidance and requirements. When a price from the pricing service is not available, values are determined by obtaining broker/dealer quotes and/or market comparables. When available, we obtain multiple quotes for the same security. The ultimate value for these securities is determined based upon our best estimate of fair value using corroborating market information. Our evaluation includes the consideration of benchmark yields, reported trades, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data. The following tables present our fair value measurements on a recurring basis by asset class and level of input: At September 30, 2017 Fair value measurements using: (in thousands) Total Quoted prices in Level 1 Observable inputs Level 2 Unobservable inputs Level 3 Available-for-sale securities: U.S. treasury $ 11,834 $ 0 $ 11,834 $ 0 States & political subdivisions 261,966 0 261,966 0 Foreign government securities 507 0 507 0 Corporate debt securities 346,372 0 338,457 7,915 Residential mortgage-backed securities 25,719 0 25,719 0 Commercial mortgage-backed securities 34,331 0 34,331 0 Collateralized debt obligations 62,381 0 62,381 0 Other debt securities 6,156 0 6,156 0 Total fixed maturities 749,266 0 741,351 7,915 Total available-for-sale securities 749,266 0 741,351 7,915 Other investments (1) 4,338 — — — Total $ 753,604 $ 0 $ 741,351 $ 7,915 At December 31, 2016 Fair value measurements using: (in thousands) Total Quoted prices in Observable inputs Unobservable inputs Available-for-sale securities: U.S. treasury $ 5,031 $ 0 $ 5,031 $ 0 Government sponsored entities 2,026 0 2,026 0 States & political subdivisions 253,132 0 253,132 0 Corporate debt securities 322,948 0 313,596 9,352 Residential mortgage-backed securities 16,102 0 16,102 0 Commercial mortgage-backed securities 36,849 0 36,849 0 Collateralized debt obligations 69,253 0 69,253 0 Other debt securities 2,000 0 2,000 0 Total fixed maturities 707,341 0 697,989 9,352 Common stock 5,950 5,950 0 0 Total available-for-sale securities 713,291 5,950 697,989 9,352 Other investments (1) 4,412 — — — Total $ 717,703 $ 5,950 $ 697,989 $ 9,352 (1) Other investments measured at fair value represent real estate funds included on the balance sheet as limited partnership investments that are reported under the fair value option using the net asset value practical expedient. These amounts are not required to be categorized in the fair value hierarchy. The investments can never be redeemed with the funds. Instead, distributions are received when liquidation of the underlying assets of the funds occur. It is estimated that the underlying assets will generally be liquidated between 5 and 10 years from the inception of the funds. The fair value of these investments is based on the net asset value (NAV) information provided by the general partner. Fair value is based on our proportionate share of the NAV based on the most recent partners' capital statements received from the general partners, which is generally one quarter prior to our balance sheet date. These values are then analyzed to determine if the NAV represents fair value at our balance sheet date, with adjustment being made where appropriate. We consider observable market data and perform a review validating the appropriateness of the NAV at each balance sheet date. It is likely that all of the investments will be redeemed at a future date for an amount different than the NAV of our ownership interest in partners' capital as of September 30, 2017 and December 31, 2016 . During the nine months ended September 30, 2017 , no contributions were made and distributions totaling $0.3 million were received from these investments. During the year ended December 31, 2016 , no contributions were made and distributions totaling $0.9 million were received from these investments. There were no unfunded commitments related to the investments as of September 30, 2017 , and $0.3 million as of December 31, 2016 . We review the fair value hierarchy classifications each reporting period. Transfers between hierarchy levels may occur due to changes in the available market observable inputs. Transfers in and out of level classifications are reported as having occurred at the beginning of the quarter in which the transfers occurred. There were no transfers between Level 1 and Level 2 for the three and nine months ended September 30, 2017 and 2016 , respectively. Level 3 Assets – Quarterly Change: (in thousands) Beginning balance at June 30, 2017 Included in earnings (1) Included income Purchases Sales Transfers into Level 3 (2) Transfers out of Level 3 (2) Ending balance at September 30, 2017 Available-for-sale securities: Corporate debt securities $ 9,295 $ 24 $ (60 ) $ 539 $ (1,240 ) $ 2,633 $ (3,276 ) $ 7,915 Total fixed maturities 9,295 24 (60 ) 539 (1,240 ) 2,633 (3,276 ) 7,915 Total available-for-sale securities 9,295 24 (60 ) 539 (1,240 ) 2,633 (3,276 ) 7,915 Total Level 3 assets $ 9,295 $ 24 $ (60 ) $ 539 $ (1,240 ) $ 2,633 $ (3,276 ) $ 7,915 Level 3 Assets – Year-to-Date Change: (in thousands) Beginning balance at December 31, 2016 Included in earnings (1) Included income Purchases Sales Transfers into Level 3 (2) Transfers out of Level 3 (2) Ending balance at September 30, 2017 Available-for-sale securities: Corporate debt securities $ 9,352 $ 3 $ (108 ) $ 4,520 $ (4,372 ) $ 8,444 $ (9,924 ) $ 7,915 Total fixed maturities 9,352 3 (108 ) 4,520 (4,372 ) 8,444 (9,924 ) 7,915 Total available-for-sale securities 9,352 3 (108 ) 4,520 (4,372 ) 8,444 (9,924 ) 7,915 Total Level 3 assets $ 9,352 $ 3 $ (108 ) $ 4,520 $ (4,372 ) $ 8,444 $ (9,924 ) $ 7,915 Level 3 Assets – Quarterly Change: (in thousands) Beginning balance at June 30, 2016 Included in earnings (1) Included in other comprehensive income Purchases Sales Transfers into Level 3 (2) Transfers out of Level 3 (2) Ending balance at September 30, 2016 Available-for-sale securities: Corporate debt securities $ 8,851 $ 22 $ 38 $ 3,217 $ (318 ) $ 2,514 $ (4,135 ) $ 10,189 Commercial mortgage-backed securities 1,003 0 0 0 0 0 (1,003 ) 0 Collateralized debt obligations 1,200 0 7 3,000 0 2,114 (1,200 ) 5,121 Total fixed maturities 11,054 22 45 6,217 (318 ) 4,628 (6,338 ) 15,310 Total available-for-sale securities 11,054 22 45 6,217 (318 ) 4,628 (6,338 ) 15,310 Total Level 3 assets $ 11,054 $ 22 $ 45 $ 6,217 $ (318 ) $ 4,628 $ (6,338 ) $ 15,310 Level 3 Assets – Year-to-Date Change: (in thousands) Beginning balance at December 31, 2015 Included in earnings (1) Included in other comprehensive income Purchases Sales Transfers into Level 3 (2) Transfers out of Level 3 (2) Ending balance at September 30, 2016 Available-for-sale securities: Corporate debt securities $ 69 $ 67 $ 119 $ 11,887 $ (924 ) $ 5,470 $ (6,499 ) $ 10,189 Commercial mortgage-backed securities 0 0 3 1,000 0 0 (1,003 ) 0 Collateralized debt obligations 8,577 4 (5 ) 7,722 (54 ) 2,114 (13,237 ) 5,121 Total fixed maturities 8,646 71 117 20,609 (978 ) 7,584 (20,739 ) 15,310 Total available-for-sale securities 8,646 71 117 20,609 (978 ) 7,584 (20,739 ) 15,310 Total Level 3 assets $ 8,646 $ 71 $ 117 $ 20,609 $ (978 ) $ 7,584 $ (20,739 ) $ 15,310 (1) These amounts are reported in the Statements of Operations as net investment income and net realized investment gains (losses) for the each of the periods presented above. (2) Transfers into and/or (out) of Level 3 are primarily attributable to the availability of market observable information and the re-evaluation of the observability of pricing inputs. Quantitative and Qualitative Disclosures about Unobservable Inputs When a non-binding broker quote was the only input available, the security was classified within Level 3. Use of non-binding broker quotes totaled $7.9 million at September 30, 2017 . The unobservable inputs are not reasonably available to us. The following table presents our fair value measurements on a recurring basis by pricing source: (in thousands) At September 30, 2017 Total Level 1 Level 2 Level 3 Fixed maturities: Priced via pricing services $ 749,266 $ 0 $ 741,351 $ 7,915 Total fixed maturities 749,266 0 741,351 7,915 Other investments: Priced via unobservable inputs (1) 4,338 — — — Total other investments 4,338 — — — Total $ 753,604 $ 0 $ 741,351 $ 7,915 (1) Other investments measured at fair value represent real estate funds included on the balance sheet as limited partnership investments that are reported under the fair value option using the net asset value practical expedient. These amounts are not required to be categorized in the fair value hierarchy. The fair value of these investments is based on the NAV information provided by the general partner. There were no assets measured at fair value on a nonrecurring basis during the nine months ended September 30, 2017 .

Investments

Investments	9 Months Ended
	Sep. 30, 2017
Investments [Abstract]
Investments	Note 5. Investments Available-for-sale securities The following tables summarize the cost and fair value of our available-for-sale securities: At September 30, 2017 (in thousands) Amortized cost Gross unrealized gains Gross unrealized losses Estimated fair value Available-for-sale securities: U.S. treasury $ 11,878 $ 0 $ 44 $ 11,834 States & political subdivisions 254,835 7,809 678 261,966 Foreign government securities 501 6 0 507 Corporate debt securities 345,003 2,201 832 346,372 Residential mortgage-backed securities 25,388 404 73 25,719 Commercial mortgage-backed securities 34,892 73 634 34,331 Collateralized debt obligations 62,193 207 19 62,381 Other debt securities 6,119 37 0 6,156 Total fixed maturities 740,809 10,737 2,280 749,266 Total available-for-sale securities $ 740,809 $ 10,737 $ 2,280 $ 749,266 At December 31, 2016 (in thousands) Amortized cost Gross unrealized gains Gross unrealized losses Estimated fair value Available-for-sale securities: U.S. treasury $ 5,093 $ 0 $ 62 $ 5,031 Government sponsored entities 2,004 22 0 2,026 States & political subdivisions 249,312 6,113 2,293 253,132 Corporate debt securities 321,041 3,293 1,386 322,948 Residential mortgage-backed securities 16,232 61 191 16,102 Commercial mortgage-backed securities 37,723 59 933 36,849 Collateralized debt obligations 68,998 351 96 69,253 Other debt securities 2,000 0 0 2,000 Total fixed maturities 702,403 9,899 4,961 707,341 Common stock 6,152 0 202 5,950 Total available-for-sale securities $ 708,555 $ 9,899 $ 5,163 $ 713,291 The amortized cost and estimated fair value of fixed maturities at September 30, 2017 are shown below by remaining contractual term to maturity. Mortgage-backed securities are allocated based upon their stated maturity dates. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. At September 30, 2017 (in thousands) Amortized Estimated cost fair value Due in one year or less $ 65,085 $ 65,208 Due after one year through five years 332,904 337,986 Due after five years through ten years 239,042 242,425 Due after ten years 103,778 103,647 Total fixed maturities $ 740,809 $ 749,266 Available-for-sale securities in a gross unrealized loss position are as follows. Data is provided by length of time for securities in a gross unrealized loss position. At September 30, 2017 (in thousands) Less than 12 months 12 months or longer Total Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses No. of holdings Available-for-sale securities: U.S. treasury $ 11,835 $ 44 $ 0 $ 0 $ 11,835 $ 44 4 States & political subdivisions 49,278 449 7,280 229 56,558 678 26 Corporate debt securities 108,828 619 19,951 213 128,779 832 255 Residential mortgage-backed securities 5,553 19 5,771 54 11,324 73 10 Commercial mortgage-backed securities 12,793 106 11,019 528 23,812 634 21 Collateralized debt obligations 16,426 19 0 0 16,426 19 8 Total fixed maturities 204,713 1,256 44,021 1,024 248,734 2,280 324 Total available-for-sale securities $ 204,713 $ 1,256 $ 44,021 $ 1,024 $ 248,734 $ 2,280 324 Quality breakdown of fixed maturities: Investment grade $ 152,341 $ 745 $ 42,020 $ 533 $ 194,361 $ 1,278 113 Non-investment grade 52,372 511 2,001 491 54,373 1,002 211 Total fixed maturities $ 204,713 $ 1,256 $ 44,021 $ 1,024 $ 248,734 $ 2,280 324 At December 31, 2016 (in thousands) Less than 12 months 12 months or longer Total Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses No. of holdings Available-for-sale securities: U.S. treasury $ 5,031 $ 62 $ 0 $ 0 $ 5,031 $ 62 1 States & political subdivisions 84,611 2,293 0 0 84,611 2,293 40 Corporate debt securities 112,453 987 8,692 399 121,145 1,386 155 Residential mortgage-backed securities 7,451 60 4,974 131 12,425 191 13 Commercial mortgage-backed securities 26,509 437 4,319 496 30,828 933 28 Collateralized debt obligations 27,470 75 4,208 21 31,678 96 15 Total fixed maturities 263,525 3,914 22,193 1,047 285,718 4,961 252 Common stock 5,950 202 0 0 5,950 202 1 Total available-for-sale securities $ 269,475 $ 4,116 $ 22,193 $ 1,047 $ 291,668 $ 5,163 253 Quality breakdown of fixed maturities: Investment grade $ 239,041 $ 3,605 $ 16,061 $ 399 $ 255,102 $ 4,004 136 Non-investment grade 24,484 309 6,132 648 30,616 957 116 Total fixed maturities $ 263,525 $ 3,914 $ 22,193 $ 1,047 $ 285,718 $ 4,961 252 The above securities have been evaluated and determined to be temporary impairments for which we expect to recover our entire principal plus interest. The primary components of this analysis include a general review of market conditions and financial performance of the issuer along with the extent and duration at which fair value is less than cost. Any securities that we intend to sell or will more likely than not be required to sell before recovery are included in other-than-temporary impairments with the impairment charges recognized in earnings. Net investment income Interest and dividend income are recognized as earned and recorded to net investment income. Investment income, net of expenses, was generated from the following portfolios: (in thousands) Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Fixed maturities $ 4,234 $ 5,245 $ 16,358 $ 14,629 Equity securities 0 50 49 132 Cash equivalents and other 1,936 366 2,852 1,011 Total investment income 6,170 5,661 19,259 15,772 Less: investment expenses 200 330 1,075 888 Net investment income $ 5,970 $ 5,331 $ 18,184 $ 14,884 Realized investment gains (losses) Realized gains and losses on sales of securities are recognized in income based upon the specific identification method. Realized gains (losses) on investments were as follows: (in thousands) Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Available-for-sale securities: Fixed maturities: Gross realized gains $ 1,621 $ 603 $ 2,708 $ 1,175 Gross realized losses (722 ) (27 ) (1,116 ) (1,819 ) Net realized gains (losses) 899 576 1,592 (644 ) Equity securities: Gross realized losses 0 0 (145 ) (34 ) Net realized losses 0 0 (145 ) (34 ) Trading securities: Common stock: Gross realized gains 0 121 0 707 Increases in fair value (1) 0 21 0 0 Net realized gains 0 142 0 707 Miscellaneous: Gross realized gains 0 0 94 0 Gross realized losses 0 0 (2 ) 0 Net realized gains 0 0 92 0 Net realized investment gains $ 899 $ 718 $ 1,539 $ 29 (1) The fair value of our common stocks is determined based upon exchange traded prices provided by a nationally recognized pricing service. Net impairment losses The components of other-than-temporary impairments on investments were as follows: (in thousands) Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Fixed maturities $ 0 $ 0 $ (182 ) $ (345 ) Total other-than-temporary impairments 0 0 (182 ) (345 ) Portion recognized in other comprehensive income 0 0 0 0 Net impairment losses recognized in earnings $ 0 $ 0 $ (182 ) $ (345 ) In considering if fixed maturity securities were credit-impaired, some of the factors considered include: potential for the default of interest and/or principal, level of subordination, collateral of the issue, compliance with financial covenants, credit ratings and industry conditions. We have the intent to sell all credit-impaired fixed maturity securities; therefore, the entire amount of the impairment charges were included in earnings and no non-credit impairments were recognized in other comprehensive income. Limited partnerships The majority of our limited partnership holdings are considered investment companies where the general partners record assets at fair value. These limited partnerships are recorded using the equity method of accounting and are generally reported on a one-quarter lag; therefore, our year-to-date limited partnership results through September 30, 2017 are comprised of partnership financial results for the fourth quarter of 2016 and the first two quarters of 2017. Given the lag in reporting, our limited partnership results do not reflect the market conditions of the third quarter of 2017 . We also own some real estate limited partnerships that do not meet the criteria of an investment company. These partnerships prepare audited financial statements on a cost basis. We have elected to report these limited partnerships under the fair value option, which is based on the NAV from our partner's capital statement reflecting the general partner's estimate of fair value for the fund's underlying assets. Fair value provides consistency in the evaluation and financial reporting for these limited partnerships and limited partnerships accounted for under the equity method. Cash contributions made to and distributions received from the partnerships are recorded in the period in which the transaction occurs. Amounts included in equity in earnings of limited partnerships by method of accounting are included below: (in thousands) Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Equity in earnings (losses) of limited partnerships accounted for under the equity method $ 1,305 $ (1,778 ) $ 1,704 $ (436 ) Change in fair value of limited partnerships accounted for under the fair value option 232 55 195 157 Equity in earnings (losses) of limited partnerships $ 1,537 $ (1,723 ) $ 1,899 $ (279 ) The following table summarizes limited partnership investments by sector: (in thousands) At September 30, 2017 At December 31, 2016 Private equity $ 33,478 $ 35,228 Mezzanine debt 4,797 6,010 Real estate 6,838 12,509 Real estate - fair value option 4,338 4,412 Total limited partnership investments $ 49,451 $ 58,159 See also Note 13, "Commitments and Contingencies" for investment commitments related to limited partnerships.

Borrowing Arrangements

Borrowing Arrangements	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Borrowing Arrangements	Note 6. Borrowing Arrangements Bank line of credit As of September 30, 2017 , we have access to a $100 million bank revolving line of credit with a $25 million letter of credit sublimit that expires on November 3, 2020 . As of September 30, 2017 , a total of $99.1 million remains available under the facility due to $0.9 million outstanding letters of credit, which reduce the availability for letters of credit to $24.1 million . We had no borrowings outstanding on our line of credit as of September 30, 2017 . Bonds with a fair value of $109.5 million were pledged as collateral on the line at September 30, 2017 . The securities pledged as collateral have no trading restrictions and are reported as available-for-sale securities in the Statements of Financial Position as of September 30, 2017 . The bank requires compliance with certain covenants, which include leverage ratios and debt restrictions, for our line of credit. We are in compliance with all bank covenants at September 30, 2017 . Term loan credit facility On November 7, 2016, we entered into a credit agreement for a $100 million senior secured draw term loan credit facility ("Credit Facility") for the acquisition of real property and construction of an office building that will serve as part of our principal headquarters. Under the agreement, $25 million will be drawn on December 1, 2016, June 1, 2017, December 1, 2017, and June 1, 2018 ("Draw Period"). During the Draw Period, we will make monthly interest only payments under the Credit Facility and thereafter the Credit Facility converts to a fully-amortized term loan with monthly payments of principal and interest over a period of 28 years . Borrowings under the Credit Facility will bear interest at a fixed rate of 4.35% . In addition, we are required to pay a quarterly commitment fee of 0.08% on the unused portion of the Credit Facility during the Draw Period. Total draws against the facility are $50 million as of September 30, 2017 . Bonds with a fair value of $109.7 million were pledged as collateral for the facility and are reported as available-for-sale securities in the Statements of Financial Position as of September 30, 2017 . The bank requires compliance with certain covenants, which include leverage ratios, debt restrictions and minimum net worth, for our Credit Facility. We are in compliance with all covenants at September 30, 2017 . Amounts drawn from the Credit Facility are reported at carrying value on our Statements of Financial Position, net of unamortized loan origination and commitment fees. The estimated fair value of this borrowing at September 30, 2017 was $47.9 million . The estimated fair value was determined using estimates based upon interest rates and credit spreads and are classified as Level 3 in the fair value hierarchy as of September 30, 2017 . The scheduled maturity of the $100 million Credit Facility begins on January 1, 2019 with annual principal payments of $1.9 million in 2019 , $2.0 million in 2020 , $2.0 million in 2021 , $2.1 million in 2022 and $92.0 million thereafter.

Postretirement Benefits

Postretirement Benefits	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Postretirement Benefits	Note 7. Postretirement Benefits Pension plans Our pension plans consist of a noncontributory defined benefit pension plan covering substantially all employees and an unfunded supplemental employee retirement plan for certain members of executive and senior management. Although we are the sponsor of these postretirement plans and record the funded status of these plans, the Exchange reimburses us for approximately 58% of the annual benefit expense of these plans, which represents pension benefits for our employees performing claims and life insurance functions and their share of service department costs. A $19.0 million contribution was made to the defined benefit pension plan in the first quarter of 2017. An additional $20.0 million contribution was made to the plan in the third quarter of 2017. Prior to 2003, the employee pension plan purchased annuities from Erie Family Life Insurance Company ("EFL"), a wholly owned subsidiary of the Exchange, for certain plan participants that were receiving benefit payments under the pension plan. These are nonparticipating annuity contracts under which EFL has unconditionally contracted to provide specified benefits to beneficiaries; however, the pension plan remains the primary obligor to the beneficiaries. A contingent liability of $19.7 million at September 30, 2017 exists in the event EFL does not honor the annuity contracts. The cost of our pension plans are as follows: (in thousands) Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Service cost for benefits earned $ 7,777 $ 7,050 $ 23,330 $ 21,150 Interest cost on benefits obligation 8,569 8,281 25,706 24,844 Expected return on plan assets (10,317 ) (9,880 ) (30,950 ) (29,640 ) Prior service cost amortization 218 174 654 522 Net actuarial loss amortization 2,325 2,029 6,975 6,084 Pension plan cost (1) $ 8,572 $ 7,654 $ 25,715 $ 22,960 (1) Pension plan costs represent the total cost before reimbursements to Indemnity from the Exchange and EFL.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Note 8. Income Taxes The effective tax rates differ from the statutory federal tax rate of 35% primarily due to permanent differences for tax exempt interest income.

Capital Stock

Capital Stock	9 Months Ended
	Sep. 30, 2017
Class of Stock Disclosures [Abstract]
Capital Stock	Note 9. Capital Stock Class A and B common stock Holders of Class B shares may, at their option, convert their shares into Class A shares at the rate of 2,400 Class A shares per Class B share. There were no shares of Class B common stock converted into Class A common stock during the nine months ended September 30, 2017 and the year ended December 31, 2016 . There is no provision for conversion of Class A shares to Class B shares, and Class B shares surrendered for conversion cannot be reissued. Stock repurchases In October 2011 , our Board of Directors approved a continuation of the current stock repurchase program for a total of $150 million , with no time limitation. There were no shares repurchased under this program during the nine months ended September 30, 2017 and the year ended December 31, 2016 . We had approximately $17.8 million of repurchase authority remaining under this program at September 30, 2017 . During the nine months ended September 30, 2017 , we purchased 58,129 shares of our outstanding Class A nonvoting common stock outside of our publicly announced share repurchase program at a total cost of $7.0 million . Of this amount, we purchased 3,785 shares for $0.4 million , or $111.55 per share, for stock-based awards in conjunction with our equity compensation plan. We purchased 7,460 shares for $0.9 million , or $121.46 per share, to fund the rabbi trust for the outside director deferred compensation plan. The remaining 46,884 shares were purchased at a total cost of $5.7 million , or $122.40 per share, for the vesting of stock-based awards in the long-term incentive plan. In 2016, we purchased 15,093 shares of our outstanding Class A nonvoting common stock outside of our publicly announced share repurchase program at a total cost of $1.5 million . Of this amount, we purchased 7,432 shares for $0.7 million , or $99.23 per share, to fund the rabbi trust for the outside director deferred compensation plan. The remaining 7,661 shares were purchased at a total cost of $0.8 million , or $98.20 per share, for the vesting of stock-based awards in the long-term incentive plan.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss)	Note 10. Accumulated Other Comprehensive Income (Loss) Changes in accumulated other comprehensive income ("AOCI") (loss) by component, including amounts reclassified to other comprehensive income ("OCI") (loss) and the related line item in the Statements of Operations where net income is presented, are as follows: (in thousands) Three months ended Three months ended September 30, 2017 September 30, 2016 Before Tax Income Tax Net Before Tax Income Tax Net Investment securities: AOCI, beginning of period $ 7,974 $ 2,791 $ 5,183 $ 13,875 $ 4,857 $ 9,018 OCI before reclassifications 643 225 418 1,121 392 729 Realized investment gains (899 ) (314 ) (585 ) (576 ) (202 ) (374 ) OCI (loss) (256 ) (89 ) (167 ) 545 190 355 AOCI, end of period $ 7,718 $ 2,702 $ 5,016 $ 14,420 $ 5,047 $ 9,373 Pension and other postretirement plans: (1) AOCI (loss), beginning of period $ (190,695 ) $ (66,744 ) $ (123,951 ) $ (152,910 ) $ (53,519 ) $ (99,391 ) AOCI (loss), end of period $ (190,695 ) $ (66,744 ) $ (123,951 ) $ (152,910 ) $ (53,519 ) $ (99,391 ) Total AOCI (loss), beginning of period $ (182,721 ) $ (63,953 ) $ (118,768 ) $ (139,035 ) $ (48,662 ) $ (90,373 ) Investment securities (256 ) (89 ) (167 ) 545 190 355 Pension and other postretirement plans 0 0 0 0 0 0 OCI (loss) (256 ) (89 ) (167 ) 545 190 355 AOCI (loss), end of period $ (182,977 ) $ (64,042 ) $ (118,935 ) $ (138,490 ) $ (48,472 ) $ (90,018 ) (in thousands) Nine months ended Nine months ended September 30, 2017 September 30, 2016 Before Tax Income Tax Net Before Tax Income Tax Net Investment securities: AOCI, beginning of period $ 3,954 $ 1,384 $ 2,570 $ 3,888 $ 1,361 $ 2,527 OCI before reclassifications 5,029 1,760 3,269 9,509 3,328 6,181 Realized investment (gains) losses (1,447 ) (506 ) (941 ) 678 237 441 Impairment losses 182 64 118 345 121 224 OCI 3,764 1,318 2,446 10,532 3,686 6,846 AOCI, end of period $ 7,718 $ 2,702 $ 5,016 $ 14,420 $ 5,047 $ 9,373 Pension and other postretirement plans: (1) AOCI (loss), beginning of period $ (190,695 ) $ (66,744 ) $ (123,951 ) $ (152,910 ) $ (53,519 ) $ (99,391 ) AOCI (loss), end of period $ (190,695 ) $ (66,744 ) $ (123,951 ) $ (152,910 ) $ (53,519 ) $ (99,391 ) Total AOCI (loss), beginning of period $ (186,741 ) $ (65,360 ) $ (121,381 ) $ (149,022 ) $ (52,158 ) $ (96,864 ) Investment securities 3,764 1,318 2,446 10,532 3,686 6,846 Pension and other postretirement plans 0 0 0 0 0 0 OCI 3,764 1,318 2,446 10,532 3,686 6,846 AOCI (loss), end of period $ (182,977 ) $ (64,042 ) $ (118,935 ) $ (138,490 ) $ (48,472 ) $ (90,018 ) (1) There are no comprehensive income items or amounts reclassified out of accumulated other comprehensive loss related to postretirement plan items during interim periods.

Related Party

Related Party	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Related Party	Note 11. Related Party Office lease We lease certain office space from the Exchange including the home office and three field office facilities. On April 28, 2017, after securing approval from the Pennsylvania Insurance Department, a new home office lease was executed between the Exchange and Indemnity, which was retroactive to January 1, 2017, when the prior lease expired. Under the new lease, rent is based on rental rates of like property in Erie, Pennsylvania and all operating expenses including utilities, cleaning, repairs, real estate taxes, property insurance and leasehold improvements will be the responsibility of the tenant (Indemnity). This lease agreement expires December 31, 2021. Under the previous lease, rents were determined considering returns on invested capital and included building operating and overhead costs. Rent costs and related operating expenses of shared facilities are allocated between Indemnity, Exchange and EFL based upon usage or square footage occupied. Total rent and operating expenses are estimated at $17.4 million for 2017 and totaled $14.3 million in 2016. In 2016, reimbursements from the Exchange and EFL related to the use of this space totaled $4.9 million .

Concentrations of Credit Risk

Concentrations of Credit Risk	9 Months Ended
	Sep. 30, 2017
Risks and Uncertainties [Abstract]
Concentrations of Credit Risk	Note 12. Concentrations of Credit Risk Financial instruments could potentially expose us to concentrations of credit risk, including unsecured receivables from the Exchange. A large majority of our revenue and receivables are from the Exchange and affiliates. See also Note 1, "Nature of Operations". Management fee amounts and other reimbursements due from the Exchange and affiliates were $428.5 million and $378.5 million at September 30, 2017 and December 31, 2016 , respectively.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 13. Commitments and Contingencies We have contractual commitments to invest up to $16.4 million related to our limited partnership investments at September 30, 2017 . These commitments are split among private equity securities of $6.6 million , mezzanine debt securities of $8.2 million , and real estate activities of $1.6 million . These commitments will be funded as required by the limited partnership agreements. We are involved in litigation arising in the ordinary course of conducting business. In accordance with current accounting standards for loss contingencies and based upon information currently known to us, we establish reserves for litigation when it is probable that a loss associated with a claim or proceeding has been incurred and the amount of the loss or range of loss can be reasonably estimated. When no amount within the range of loss is a better estimate than any other amount, we accrue the minimum amount of the estimable loss. To the extent that such litigation against us may have an exposure to a loss in excess of the amount we have accrued, we believe that such excess would not be material to our financial condition, results of operations, or cash flows. Legal fees are expensed as incurred. We believe that our accruals for legal proceedings are appropriate and, individually and in the aggregate, are not expected to be material to our financial condition, results of operations, or cash flows. We review all litigation on an ongoing basis when making accrual and disclosure decisions. For certain legal proceedings, we cannot reasonably estimate losses or a range of loss, if any, particularly for proceedings that are in their early stages of development or where the plaintiffs seek indeterminate damages. Various factors, including, but not limited to, the outcome of potentially lengthy discovery and the resolution of important factual questions, may need to be determined before probability can be established or before a loss or range of loss can be reasonably estimated. If the loss contingency in question is not both probable and reasonably estimable, we do not establish an accrual and the matter will continue to be monitored for any developments that would make the loss contingency both probable and reasonably estimable. In the event that a legal proceeding results in a substantial judgment against, or settlement by, us, there can be no assurance that any resulting liability or financial commitment would not have a material adverse effect on the financial condition, results of operations, or cash flows.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Note 14. Subsequent Events No items were identified in this period subsequent to the financial statement date that required adjustment or additional disclosure.

Significant Accounting Polici21

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation The accompanying unaudited financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the nine months ended September 30, 2017 are not necessarily indicative of the results that may be expected for the year ending December 31, 2017 . For further information, refer to the financial statements and footnotes included in our Form 10-K for the year ended December 31, 2016 as filed with the Securities and Exchange Commission on February 23, 2017 .
Use of estimates	Use of estimates The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Recently issued accounting standards	Recently issued accounting standards In March 2017, the FASB issued ASU 2017-07, "Compensation-Retirement Benefits", which requires the service cost component of net benefit costs to be reported with other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit costs are required to be presented separately from the service cost component and outside of income from operations. This amendment also allows only the service cost component to be eligible for capitalization when applicable. The guidance is effective for interim and annual periods beginning after December 15, 2017. While the presentation of the costs within the Statements of Operations will change, we do not expect a material impact on our financial statements or related disclosures. In March 2017, the FASB issued ASU 2017-08, "Receivables-Nonrefundable Fees and Other Costs" , which shortens the amortization period for certain purchased callable debt securities held at a premium from maturity date to the earliest call date. ASU 2017-08 is effective for interim and annual reporting periods beginning after December 31, 2018. The guidance should be applied using a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. Early adoption is permitted, including adoption in an interim period. We do not expect the adoption of this guidance to have a material impact on our financial statements. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments-Credit Losses" , which requires financial assets measured at amortized cost to be presented at the net amount expected to be collected through the use of a new forward-looking expected loss model and credit losses relating to available-for-sale debt securities to be recognized through an allowance for credit losses. ASU 2016-13 is effective for interim and annual reporting periods beginning after December 15, 2019. Early adoption for interim and annual periods beginning after December 15, 2018 is permitted. We have evaluated the impact of this guidance on our invested assets. Our investments are not measured at amortized cost, which are the investments that require the use of a new expected loss model. Our available-for-sale debt securities will continue to be monitored for credit losses which would be reflected as an allowance for credit losses rather than a reduction of the carrying value of the asset. The other material financial assets subject to this guidance include our receivables from Erie Insurance Exchange and affiliates. Given the financial strength of the Exchange, demonstrated by its strong surplus position and industry ratings, it is unlikely these receivables would have significant, if any, credit loss exposure. We do not expect a material impact on our financial statements or related disclosures as a result of this guidance. In February 2016, the FASB issued ASU 2016-02, "Leases" , which requires lessees to recognize assets and liabilities arising from operating leases on the statement of financial position and to disclose key information about leasing arrangements. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Leases are required to be recognized and measured at the beginning of the earliest period presented using a modified retrospective approach. Early adoption is permitted. We expect to adopt ASU 2016-02 as of January 1, 2019 using the modified retrospective method. Under existing guidance, we recognize lease expense as a component of operating expenses in the Statements of Operations. We are in the process of evaluating our existing lease contracts to determine the impact to our financial statements and disclosures. In January 2016, the FASB issued ASU 2016-01, "Financial Instruments-Overall" . ASU 2016-01 revises the accounting related to the classification and measurement of investments in equity securities and the presentation of certain fair value changes for financial liabilities measured at fair value. ASU 2016-01 is effective for interim and annual reporting periods beginning after December 15, 2017. As of September 30, 2017, we do not own any equity security investments, therefore the adoption of this guidance would have no impact to our financial statements. We will continue to monitor our investment portfolio as we may enter into investments in equity securities; however, at this time we do not expect that recognizing the change in fair value of future equity investments through net income instead of accumulated other comprehensive income would be material. In May 2014, the FASB issued ASU 2014-09, "Revenue from Contracts with Customers" . ASU 2014-09 requires an entity to recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The guidance is effective for fiscal years beginning after December 15, 2017, including interim periods within that reporting period with early application permitted beginning in the first interim period in 2017. We expect to adopt the ASU 2014-09 as of January 1, 2018 under the modified retrospective method where the cumulative effect is recognized at the date of initial application. Our evaluation is ongoing and not complete. We performed an analysis in accordance with the steps identified in the new guidance around the recognition, measurement, and presentation of management fee revenue. We determined that service fee revenue is not within the scope of the new guidance. We have preliminarily concluded that adoption of this guidance will not have a material impact on our management fee revenue recognition pattern or our financial statements. We are also reviewing agreements related to the amounts we receive as reimbursements from the Exchange and its subsidiaries, such as claims-related expenses, investment and other overhead expenses. While the expenses are reimbursed to us at actual cost, we are evaluating if there is a performance obligation that would require allocation of revenue under this guidance. Additionally, we are evaluating the impact of the new disclosure requirements.
Earnings per share	Class A and Class B basic earnings per share and Class B diluted earnings per share are calculated under the two-class method. The two-class method allocates earnings to each class of stock based upon its dividend rights. Class B shares are convertible into Class A shares at a conversion ratio of 2,400 to 1. See Note 9, "Capital Stock". Class A diluted earnings per share are calculated under the if-converted method, which reflects the conversion of Class B shares to Class A shares. Diluted earnings per share calculations include the dilutive effect of assumed issuance of stock-based awards under compensation plans that have the option to be paid in stock using the treasury stock method.
Fair value of financial instruments	Our available-for-sale and trading securities are recorded at fair value, which is the price that would be received to sell the asset in an orderly transaction between willing market participants as of the measurement date. Valuation techniques used to derive the fair value of our available-for-sale and trading securities are based upon observable and unobservable inputs. Observable inputs reflect market data obtained from independent sources. Unobservable inputs reflect our own assumptions regarding fair market value for these securities. Although virtually all of our prices are obtained from third party sources, we also perform an internal pricing review on outliers, which include securities with price changes inconsistent with current market conditions. Financial instruments are categorized based upon the following characteristics or inputs to the valuation techniques: • Level 1 – Quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity can access at the measurement date. • Level 2 – Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. • Level 3 – Unobservable inputs for the asset or liability. Estimates of fair values for our investment portfolio are obtained primarily from a nationally recognized pricing service. Our Level 1 category includes those securities valued using an exchange traded price provided by the pricing service. The methodologies used by the pricing service that support a Level 2 classification of a financial instrument include multiple verifiable, observable inputs including benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data. Pricing service valuations for Level 3 securities are based upon proprietary models and are used when observable inputs are not available or in illiquid markets. In limited circumstances we adjust the price received from the pricing service when, in our judgment, a better reflection of fair value is available based upon corroborating information and our knowledge and monitoring of market conditions such as a disparity in price of comparable securities and/or non-binding broker quotes. In other circumstances, certain securities are internally priced because prices are not provided by the pricing service. We perform continuous reviews of the prices obtained from the pricing service. This includes evaluating the methodology and inputs used by the pricing service to ensure that we determine the proper classification level of the financial instrument. Price variances, including large periodic changes, are investigated and corroborated by market data. We have reviewed the pricing methodologies of our pricing service as well as other observable inputs, such as data, and transaction volumes and believe that their prices adequately consider market activity in determining fair value. Our review process continues to evolve based upon accounting guidance and requirements. When a price from the pricing service is not available, values are determined by obtaining broker/dealer quotes and/or market comparables. When available, we obtain multiple quotes for the same security. The ultimate value for these securities is determined based upon our best estimate of fair value using corroborating market information. Our evaluation includes the consideration of benchmark yields, reported trades, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data.
Fair value of financial instruments, transfers between levels	We review the fair value hierarchy classifications each reporting period. Transfers between hierarchy levels may occur due to changes in the available market observable inputs. Transfers in and out of level classifications are reported as having occurred at the beginning of the quarter in which the transfers occurred.
Investments - Limited partnerships	The majority of our limited partnership holdings are considered investment companies where the general partners record assets at fair value. These limited partnerships are recorded using the equity method of accounting and are generally reported on a one-quarter lag; therefore, our year-to-date limited partnership results through September 30, 2017 are comprised of partnership financial results for the fourth quarter of 2016 and the first two quarters of 2017. Given the lag in reporting, our limited partnership results do not reflect the market conditions of the third quarter of 2017 . We also own some real estate limited partnerships that do not meet the criteria of an investment company. These partnerships prepare audited financial statements on a cost basis. We have elected to report these limited partnerships under the fair value option, which is based on the NAV from our partner's capital statement reflecting the general partner's estimate of fair value for the fund's underlying assets. Fair value provides consistency in the evaluation and financial reporting for these limited partnerships and limited partnerships accounted for under the equity method. Cash contributions made to and distributions received from the partnerships are recorded in the period in which the transaction occurs.
Commitments and contingencies	We are involved in litigation arising in the ordinary course of conducting business. In accordance with current accounting standards for loss contingencies and based upon information currently known to us, we establish reserves for litigation when it is probable that a loss associated with a claim or proceeding has been incurred and the amount of the loss or range of loss can be reasonably estimated. When no amount within the range of loss is a better estimate than any other amount, we accrue the minimum amount of the estimable loss. To the extent that such litigation against us may have an exposure to a loss in excess of the amount we have accrued, we believe that such excess would not be material to our financial condition, results of operations, or cash flows. Legal fees are expensed as incurred. We believe that our accruals for legal proceedings are appropriate and, individually and in the aggregate, are not expected to be material to our financial condition, results of operations, or cash flows. We review all litigation on an ongoing basis when making accrual and disclosure decisions. For certain legal proceedings, we cannot reasonably estimate losses or a range of loss, if any, particularly for proceedings that are in their early stages of development or where the plaintiffs seek indeterminate damages. Various factors, including, but not limited to, the outcome of potentially lengthy discovery and the resolution of important factual questions, may need to be determined before probability can be established or before a loss or range of loss can be reasonably estimated. If the loss contingency in question is not both probable and reasonably estimable, we do not establish an accrual and the matter will continue to be monitored for any developments that would make the loss contingency both probable and reasonably estimable. In the event that a legal proceeding results in a substantial judgment against, or settlement by, us, there can be no assurance that any resulting liability or financial commitment would not have a material adverse effect on the financial condition, results of operations, or cash flows.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Schedule of reconciliation of the numerators and denominators used in the basic and diluted per-share computations	A reconciliation of the numerators and denominators used in the basic and diluted per-share computations is presented as follows for each class of common stock: Three months ended September 30, 2017 2016 (dollars in thousands, except per share data) Allocated net income (numerator) Weighted shares (denominator) Per-share amount Allocated net income (numerator) Weighted shares (denominator) Per-share amount Class A – Basic EPS: Income available to Class A stockholders $ 58,064 46,188,949 $ 1.26 $ 56,906 46,188,980 $ 1.23 Dilutive effect of stock-based awards 0 27,127 — 0 121,523 — Assumed conversion of Class B shares 479 6,100,800 — 470 6,100,800 — Class A – Diluted EPS: Income available to Class A stockholders on Class A equivalent shares $ 58,543 52,316,876 $ 1.12 $ 57,376 52,411,303 $ 1.09 Class B – Basic EPS: Income available to Class B stockholders $ 479 2,542 $ 189 $ 470 2,542 $ 185 Class B – Diluted EPS: Income available to Class B stockholders $ 479 2,542 $ 189 $ 469 2,542 $ 185 Nine months ended September 30, 2017 2016 (dollars in thousands, except per share data) Allocated net income (numerator) Weighted shares (denominator) Per-share amount Allocated net income (numerator) Weighted shares (denominator) Per-share amount Class A – Basic EPS: Income available to Class A stockholders $ 163,596 46,186,109 $ 3.54 $ 163,233 46,188,971 $ 3.53 Dilutive effect of stock-based awards 0 55,541 — 0 152,926 — Assumed conversion of Class B shares 1,350 6,100,800 — 1,347 6,100,800 — Class A – Diluted EPS: Income available to Class A stockholders on Class A equivalent shares $ 164,946 52,342,450 $ 3.15 $ 164,580 52,442,697 $ 3.14 Class B – Basic EPS: Income available to Class B stockholders $ 1,350 2,542 $ 531 $ 1,347 2,542 $ 530 Class B – Diluted EPS: Income available to Class B stockholders $ 1,350 2,542 $ 531 $ 1,346 2,542 $ 529

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of fair value measurements on a recurring basis by asset class and level of input	The following tables present our fair value measurements on a recurring basis by asset class and level of input: At September 30, 2017 Fair value measurements using: (in thousands) Total Quoted prices in Level 1 Observable inputs Level 2 Unobservable inputs Level 3 Available-for-sale securities: U.S. treasury $ 11,834 $ 0 $ 11,834 $ 0 States & political subdivisions 261,966 0 261,966 0 Foreign government securities 507 0 507 0 Corporate debt securities 346,372 0 338,457 7,915 Residential mortgage-backed securities 25,719 0 25,719 0 Commercial mortgage-backed securities 34,331 0 34,331 0 Collateralized debt obligations 62,381 0 62,381 0 Other debt securities 6,156 0 6,156 0 Total fixed maturities 749,266 0 741,351 7,915 Total available-for-sale securities 749,266 0 741,351 7,915 Other investments (1) 4,338 — — — Total $ 753,604 $ 0 $ 741,351 $ 7,915 At December 31, 2016 Fair value measurements using: (in thousands) Total Quoted prices in Observable inputs Unobservable inputs Available-for-sale securities: U.S. treasury $ 5,031 $ 0 $ 5,031 $ 0 Government sponsored entities 2,026 0 2,026 0 States & political subdivisions 253,132 0 253,132 0 Corporate debt securities 322,948 0 313,596 9,352 Residential mortgage-backed securities 16,102 0 16,102 0 Commercial mortgage-backed securities 36,849 0 36,849 0 Collateralized debt obligations 69,253 0 69,253 0 Other debt securities 2,000 0 2,000 0 Total fixed maturities 707,341 0 697,989 9,352 Common stock 5,950 5,950 0 0 Total available-for-sale securities 713,291 5,950 697,989 9,352 Other investments (1) 4,412 — — — Total $ 717,703 $ 5,950 $ 697,989 $ 9,352 (1) Other investments measured at fair value represent real estate funds included on the balance sheet as limited partnership investments that are reported under the fair value option using the net asset value practical expedient. These amounts are not required to be categorized in the fair value hierarchy. The investments can never be redeemed with the funds. Instead, distributions are received when liquidation of the underlying assets of the funds occur. It is estimated that the underlying assets will generally be liquidated between 5 and 10 years from the inception of the funds. The fair value of these investments is based on the net asset value (NAV) information provided by the general partner. Fair value is based on our proportionate share of the NAV based on the most recent partners' capital statements received from the general partners, which is generally one quarter prior to our balance sheet date. These values are then analyzed to determine if the NAV represents fair value at our balance sheet date, with adjustment being made where appropriate. We consider observable market data and perform a review validating the appropriateness of the NAV at each balance sheet date. It is likely that all of the investments will be redeemed at a future date for an amount different than the NAV of our ownership interest in partners' capital as of September 30, 2017 and December 31, 2016 . During the nine months ended September 30, 2017 , no contributions were made and distributions totaling $0.3 million were received from these investments. During the year ended December 31, 2016 , no contributions were made and distributions totaling $0.9 million were received from these investments. There were no unfunded commitments related to the investments as of September 30, 2017 , and $0.3 million as of December 31, 2016 .
Schedule of roll forward of Level 3 fair value measurements on a recurring basis	Level 3 Assets – Quarterly Change: (in thousands) Beginning balance at June 30, 2017 Included in earnings (1) Included income Purchases Sales Transfers into Level 3 (2) Transfers out of Level 3 (2) Ending balance at September 30, 2017 Available-for-sale securities: Corporate debt securities $ 9,295 $ 24 $ (60 ) $ 539 $ (1,240 ) $ 2,633 $ (3,276 ) $ 7,915 Total fixed maturities 9,295 24 (60 ) 539 (1,240 ) 2,633 (3,276 ) 7,915 Total available-for-sale securities 9,295 24 (60 ) 539 (1,240 ) 2,633 (3,276 ) 7,915 Total Level 3 assets $ 9,295 $ 24 $ (60 ) $ 539 $ (1,240 ) $ 2,633 $ (3,276 ) $ 7,915 Level 3 Assets – Year-to-Date Change: (in thousands) Beginning balance at December 31, 2016 Included in earnings (1) Included income Purchases Sales Transfers into Level 3 (2) Transfers out of Level 3 (2) Ending balance at September 30, 2017 Available-for-sale securities: Corporate debt securities $ 9,352 $ 3 $ (108 ) $ 4,520 $ (4,372 ) $ 8,444 $ (9,924 ) $ 7,915 Total fixed maturities 9,352 3 (108 ) 4,520 (4,372 ) 8,444 (9,924 ) 7,915 Total available-for-sale securities 9,352 3 (108 ) 4,520 (4,372 ) 8,444 (9,924 ) 7,915 Total Level 3 assets $ 9,352 $ 3 $ (108 ) $ 4,520 $ (4,372 ) $ 8,444 $ (9,924 ) $ 7,915 Level 3 Assets – Quarterly Change: (in thousands) Beginning balance at June 30, 2016 Included in earnings (1) Included in other comprehensive income Purchases Sales Transfers into Level 3 (2) Transfers out of Level 3 (2) Ending balance at September 30, 2016 Available-for-sale securities: Corporate debt securities $ 8,851 $ 22 $ 38 $ 3,217 $ (318 ) $ 2,514 $ (4,135 ) $ 10,189 Commercial mortgage-backed securities 1,003 0 0 0 0 0 (1,003 ) 0 Collateralized debt obligations 1,200 0 7 3,000 0 2,114 (1,200 ) 5,121 Total fixed maturities 11,054 22 45 6,217 (318 ) 4,628 (6,338 ) 15,310 Total available-for-sale securities 11,054 22 45 6,217 (318 ) 4,628 (6,338 ) 15,310 Total Level 3 assets $ 11,054 $ 22 $ 45 $ 6,217 $ (318 ) $ 4,628 $ (6,338 ) $ 15,310 Level 3 Assets – Year-to-Date Change: (in thousands) Beginning balance at December 31, 2015 Included in earnings (1) Included in other comprehensive income Purchases Sales Transfers into Level 3 (2) Transfers out of Level 3 (2) Ending balance at September 30, 2016 Available-for-sale securities: Corporate debt securities $ 69 $ 67 $ 119 $ 11,887 $ (924 ) $ 5,470 $ (6,499 ) $ 10,189 Commercial mortgage-backed securities 0 0 3 1,000 0 0 (1,003 ) 0 Collateralized debt obligations 8,577 4 (5 ) 7,722 (54 ) 2,114 (13,237 ) 5,121 Total fixed maturities 8,646 71 117 20,609 (978 ) 7,584 (20,739 ) 15,310 Total available-for-sale securities 8,646 71 117 20,609 (978 ) 7,584 (20,739 ) 15,310 Total Level 3 assets $ 8,646 $ 71 $ 117 $ 20,609 $ (978 ) $ 7,584 $ (20,739 ) $ 15,310 (1) These amounts are reported in the Statements of Operations as net investment income and net realized investment gains (losses) for the each of the periods presented above. (2) Transfers into and/or (out) of Level 3 are primarily attributable to the availability of market observable information and the re-evaluation of the observability of pricing inputs.
Schedule of fair value measurements on a recurring basis by pricing source	The following table presents our fair value measurements on a recurring basis by pricing source: (in thousands) At September 30, 2017 Total Level 1 Level 2 Level 3 Fixed maturities: Priced via pricing services $ 749,266 $ 0 $ 741,351 $ 7,915 Total fixed maturities 749,266 0 741,351 7,915 Other investments: Priced via unobservable inputs (1) 4,338 — — — Total other investments 4,338 — — — Total $ 753,604 $ 0 $ 741,351 $ 7,915 (1) Other investments measured at fair value represent real estate funds included on the balance sheet as limited partnership investments that are reported under the fair value option using the net asset value practical expedient. These amounts are not required to be categorized in the fair value hierarchy. The fair value of these investments is based on the NAV information provided by the general partner.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Investments [Abstract]
Schedule of reconciliation of cost to fair value of available-for-sale securities	The following tables summarize the cost and fair value of our available-for-sale securities: At September 30, 2017 (in thousands) Amortized cost Gross unrealized gains Gross unrealized losses Estimated fair value Available-for-sale securities: U.S. treasury $ 11,878 $ 0 $ 44 $ 11,834 States & political subdivisions 254,835 7,809 678 261,966 Foreign government securities 501 6 0 507 Corporate debt securities 345,003 2,201 832 346,372 Residential mortgage-backed securities 25,388 404 73 25,719 Commercial mortgage-backed securities 34,892 73 634 34,331 Collateralized debt obligations 62,193 207 19 62,381 Other debt securities 6,119 37 0 6,156 Total fixed maturities 740,809 10,737 2,280 749,266 Total available-for-sale securities $ 740,809 $ 10,737 $ 2,280 $ 749,266 At December 31, 2016 (in thousands) Amortized cost Gross unrealized gains Gross unrealized losses Estimated fair value Available-for-sale securities: U.S. treasury $ 5,093 $ 0 $ 62 $ 5,031 Government sponsored entities 2,004 22 0 2,026 States & political subdivisions 249,312 6,113 2,293 253,132 Corporate debt securities 321,041 3,293 1,386 322,948 Residential mortgage-backed securities 16,232 61 191 16,102 Commercial mortgage-backed securities 37,723 59 933 36,849 Collateralized debt obligations 68,998 351 96 69,253 Other debt securities 2,000 0 0 2,000 Total fixed maturities 702,403 9,899 4,961 707,341 Common stock 6,152 0 202 5,950 Total available-for-sale securities $ 708,555 $ 9,899 $ 5,163 $ 713,291
Schedule of amortized cost and estimated fair value of fixed maturities by remaining contractual term to maturity	The amortized cost and estimated fair value of fixed maturities at September 30, 2017 are shown below by remaining contractual term to maturity. Mortgage-backed securities are allocated based upon their stated maturity dates. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. At September 30, 2017 (in thousands) Amortized Estimated cost fair value Due in one year or less $ 65,085 $ 65,208 Due after one year through five years 332,904 337,986 Due after five years through ten years 239,042 242,425 Due after ten years 103,778 103,647 Total fixed maturities $ 740,809 $ 749,266
Schedule of available-for-sale securities in a gross unrealized loss position by length of time	Available-for-sale securities in a gross unrealized loss position are as follows. Data is provided by length of time for securities in a gross unrealized loss position. At September 30, 2017 (in thousands) Less than 12 months 12 months or longer Total Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses No. of holdings Available-for-sale securities: U.S. treasury $ 11,835 $ 44 $ 0 $ 0 $ 11,835 $ 44 4 States & political subdivisions 49,278 449 7,280 229 56,558 678 26 Corporate debt securities 108,828 619 19,951 213 128,779 832 255 Residential mortgage-backed securities 5,553 19 5,771 54 11,324 73 10 Commercial mortgage-backed securities 12,793 106 11,019 528 23,812 634 21 Collateralized debt obligations 16,426 19 0 0 16,426 19 8 Total fixed maturities 204,713 1,256 44,021 1,024 248,734 2,280 324 Total available-for-sale securities $ 204,713 $ 1,256 $ 44,021 $ 1,024 $ 248,734 $ 2,280 324 Quality breakdown of fixed maturities: Investment grade $ 152,341 $ 745 $ 42,020 $ 533 $ 194,361 $ 1,278 113 Non-investment grade 52,372 511 2,001 491 54,373 1,002 211 Total fixed maturities $ 204,713 $ 1,256 $ 44,021 $ 1,024 $ 248,734 $ 2,280 324 At December 31, 2016 (in thousands) Less than 12 months 12 months or longer Total Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses No. of holdings Available-for-sale securities: U.S. treasury $ 5,031 $ 62 $ 0 $ 0 $ 5,031 $ 62 1 States & political subdivisions 84,611 2,293 0 0 84,611 2,293 40 Corporate debt securities 112,453 987 8,692 399 121,145 1,386 155 Residential mortgage-backed securities 7,451 60 4,974 131 12,425 191 13 Commercial mortgage-backed securities 26,509 437 4,319 496 30,828 933 28 Collateralized debt obligations 27,470 75 4,208 21 31,678 96 15 Total fixed maturities 263,525 3,914 22,193 1,047 285,718 4,961 252 Common stock 5,950 202 0 0 5,950 202 1 Total available-for-sale securities $ 269,475 $ 4,116 $ 22,193 $ 1,047 $ 291,668 $ 5,163 253 Quality breakdown of fixed maturities: Investment grade $ 239,041 $ 3,605 $ 16,061 $ 399 $ 255,102 $ 4,004 136 Non-investment grade 24,484 309 6,132 648 30,616 957 116 Total fixed maturities $ 263,525 $ 3,914 $ 22,193 $ 1,047 $ 285,718 $ 4,961 252
Schedule of investment income, net of expenses, from portfolios	Interest and dividend income are recognized as earned and recorded to net investment income. Investment income, net of expenses, was generated from the following portfolios: (in thousands) Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Fixed maturities $ 4,234 $ 5,245 $ 16,358 $ 14,629 Equity securities 0 50 49 132 Cash equivalents and other 1,936 366 2,852 1,011 Total investment income 6,170 5,661 19,259 15,772 Less: investment expenses 200 330 1,075 888 Net investment income $ 5,970 $ 5,331 $ 18,184 $ 14,884
Schedule of realized gains and losses on sales of securities recognized in income based upon the specific identification method	Realized gains and losses on sales of securities are recognized in income based upon the specific identification method. Realized gains (losses) on investments were as follows: (in thousands) Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Available-for-sale securities: Fixed maturities: Gross realized gains $ 1,621 $ 603 $ 2,708 $ 1,175 Gross realized losses (722 ) (27 ) (1,116 ) (1,819 ) Net realized gains (losses) 899 576 1,592 (644 ) Equity securities: Gross realized losses 0 0 (145 ) (34 ) Net realized losses 0 0 (145 ) (34 ) Trading securities: Common stock: Gross realized gains 0 121 0 707 Increases in fair value (1) 0 21 0 0 Net realized gains 0 142 0 707 Miscellaneous: Gross realized gains 0 0 94 0 Gross realized losses 0 0 (2 ) 0 Net realized gains 0 0 92 0 Net realized investment gains $ 899 $ 718 $ 1,539 $ 29 (1) The fair value of our common stocks is determined based upon exchange traded prices provided by a nationally recognized pricing service.
Schedule of components of other-than-temporary impairments on investments	The components of other-than-temporary impairments on investments were as follows: (in thousands) Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Fixed maturities $ 0 $ 0 $ (182 ) $ (345 ) Total other-than-temporary impairments 0 0 (182 ) (345 ) Portion recognized in other comprehensive income 0 0 0 0 Net impairment losses recognized in earnings $ 0 $ 0 $ (182 ) $ (345 )
Schedule of limited partnership results, generally reported on a one-quarter lag	Amounts included in equity in earnings of limited partnerships by method of accounting are included below: (in thousands) Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Equity in earnings (losses) of limited partnerships accounted for under the equity method $ 1,305 $ (1,778 ) $ 1,704 $ (436 ) Change in fair value of limited partnerships accounted for under the fair value option 232 55 195 157 Equity in earnings (losses) of limited partnerships $ 1,537 $ (1,723 ) $ 1,899 $ (279 ) The following table summarizes limited partnership investments by sector: (in thousands) At September 30, 2017 At December 31, 2016 Private equity $ 33,478 $ 35,228 Mezzanine debt 4,797 6,010 Real estate 6,838 12,509 Real estate - fair value option 4,338 4,412 Total limited partnership investments $ 49,451 $ 58,159

Postretirement Benefits (Tables

Postretirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Schedule of cost of pension plans	The cost of our pension plans are as follows: (in thousands) Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Service cost for benefits earned $ 7,777 $ 7,050 $ 23,330 $ 21,150 Interest cost on benefits obligation 8,569 8,281 25,706 24,844 Expected return on plan assets (10,317 ) (9,880 ) (30,950 ) (29,640 ) Prior service cost amortization 218 174 654 522 Net actuarial loss amortization 2,325 2,029 6,975 6,084 Pension plan cost (1) $ 8,572 $ 7,654 $ 25,715 $ 22,960 (1) Pension plan costs represent the total cost before reimbursements to Indemnity from the Exchange and EFL.

Accumulated Other Comprehensi26

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of changes in accumulated other comprehensive income (loss) by component, including amounts reclassified to other comprehensive income (loss) and the related line item in the Statements of Operations where net income is presented	Changes in accumulated other comprehensive income ("AOCI") (loss) by component, including amounts reclassified to other comprehensive income ("OCI") (loss) and the related line item in the Statements of Operations where net income is presented, are as follows: (in thousands) Three months ended Three months ended September 30, 2017 September 30, 2016 Before Tax Income Tax Net Before Tax Income Tax Net Investment securities: AOCI, beginning of period $ 7,974 $ 2,791 $ 5,183 $ 13,875 $ 4,857 $ 9,018 OCI before reclassifications 643 225 418 1,121 392 729 Realized investment gains (899 ) (314 ) (585 ) (576 ) (202 ) (374 ) OCI (loss) (256 ) (89 ) (167 ) 545 190 355 AOCI, end of period $ 7,718 $ 2,702 $ 5,016 $ 14,420 $ 5,047 $ 9,373 Pension and other postretirement plans: (1) AOCI (loss), beginning of period $ (190,695 ) $ (66,744 ) $ (123,951 ) $ (152,910 ) $ (53,519 ) $ (99,391 ) AOCI (loss), end of period $ (190,695 ) $ (66,744 ) $ (123,951 ) $ (152,910 ) $ (53,519 ) $ (99,391 ) Total AOCI (loss), beginning of period $ (182,721 ) $ (63,953 ) $ (118,768 ) $ (139,035 ) $ (48,662 ) $ (90,373 ) Investment securities (256 ) (89 ) (167 ) 545 190 355 Pension and other postretirement plans 0 0 0 0 0 0 OCI (loss) (256 ) (89 ) (167 ) 545 190 355 AOCI (loss), end of period $ (182,977 ) $ (64,042 ) $ (118,935 ) $ (138,490 ) $ (48,472 ) $ (90,018 ) (in thousands) Nine months ended Nine months ended September 30, 2017 September 30, 2016 Before Tax Income Tax Net Before Tax Income Tax Net Investment securities: AOCI, beginning of period $ 3,954 $ 1,384 $ 2,570 $ 3,888 $ 1,361 $ 2,527 OCI before reclassifications 5,029 1,760 3,269 9,509 3,328 6,181 Realized investment (gains) losses (1,447 ) (506 ) (941 ) 678 237 441 Impairment losses 182 64 118 345 121 224 OCI 3,764 1,318 2,446 10,532 3,686 6,846 AOCI, end of period $ 7,718 $ 2,702 $ 5,016 $ 14,420 $ 5,047 $ 9,373 Pension and other postretirement plans: (1) AOCI (loss), beginning of period $ (190,695 ) $ (66,744 ) $ (123,951 ) $ (152,910 ) $ (53,519 ) $ (99,391 ) AOCI (loss), end of period $ (190,695 ) $ (66,744 ) $ (123,951 ) $ (152,910 ) $ (53,519 ) $ (99,391 ) Total AOCI (loss), beginning of period $ (186,741 ) $ (65,360 ) $ (121,381 ) $ (149,022 ) $ (52,158 ) $ (96,864 ) Investment securities 3,764 1,318 2,446 10,532 3,686 6,846 Pension and other postretirement plans 0 0 0 0 0 0 OCI 3,764 1,318 2,446 10,532 3,686 6,846 AOCI (loss), end of period $ (182,977 ) $ (64,042 ) $ (118,935 ) $ (138,490 ) $ (48,472 ) $ (90,018 ) (1) There are no comprehensive income items or amounts reclassified out of accumulated other comprehensive loss related to postretirement plan items during interim periods.

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Class A
Income available to stockholders (Basic EPS:)
Allocated net income (numerator) (in dollars)	$ 58,064	$ 56,906	$ 163,596	$ 163,233
Weighted shares (denominator) (in shares)	46,188,949	46,188,980	46,186,109	46,188,971
Per-share amount (in dollars per share)	$ 1.26	$ 1.23	$ 3.54	$ 3.53
Dilutive effect of stock-based awards
Allocated net income (numerator) (in dollars)	$ 0	$ 0	$ 0	$ 0
Weighted shares (denominator) (in shares)	27,127	121,523	55,541	152,926
Assumed conversion of Class B shares
Allocated net income (numerator) (in dollars)	$ 479	$ 470	$ 1,350	$ 1,347
Weighted shares (denominator) (in shares)	6,100,800	6,100,800	6,100,800	6,100,800
Income available to stockholders on equivalent shares (Diluted EPS:)
Allocated net income (numerator) (in dollars)	$ 58,543	$ 57,376	$ 164,946	$ 164,580
Weighted shares (denominator) (in shares)	52,316,876	52,411,303	52,342,450	52,442,697
Per-share amount (in dollars per share)	$ 1.12	$ 1.09	$ 3.15	$ 3.14
Class B
Reconciliation of the numerators and denominators used in the basic and diluted per-share computations
Ratio for converting shares of Class B common stock into shares of Class A common stock (as a percent)	2400.00%		2400.00%		2400.00%
Income available to stockholders (Basic EPS:)
Allocated net income (numerator) (in dollars)	$ 479	$ 470	$ 1,350	$ 1,347
Weighted shares (denominator) (in shares)	2,542	2,542	2,542	2,542
Per-share amount (in dollars per share)	$ 189	$ 185	$ 531	$ 530
Income available to stockholders on equivalent shares (Diluted EPS:)
Allocated net income (numerator) (in dollars)	$ 479	$ 469	$ 1,350	$ 1,346
Weighted shares (denominator) (in shares)	2,542	2,542	2,542	2,542
Per-share amount (in dollars per share)	$ 189	$ 185	$ 531	$ 529

Fair Value (Details)

Fair Value (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	$ 749,266		$ 713,291
Other investments:
Contributions made to the funds	330	$ 449
Distributions received from the funds	7,986	$ 12,404
Fair value measurements on a recurring basis
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	749,266		713,291
Total	753,604		717,703
Fair value measurements on a recurring basis | Fixed maturities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	749,266		707,341
Fair value measurements on a recurring basis | U.S. treasury
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	11,834		5,031
Fair value measurements on a recurring basis | Government sponsored entities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities			2,026
Fair value measurements on a recurring basis | States & political subdivisions
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	261,966		253,132
Fair value measurements on a recurring basis | Foreign government securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	507
Fair value measurements on a recurring basis | Corporate debt securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	346,372		322,948
Fair value measurements on a recurring basis | Residential mortgage-backed securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	25,719		16,102
Fair value measurements on a recurring basis | Commercial mortgage-backed securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	34,331		36,849
Fair value measurements on a recurring basis | Collateralized debt obligations
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	62,381		69,253
Fair value measurements on a recurring basis | Other debt securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	6,156		2,000
Fair value measurements on a recurring basis | Common stock
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities			5,950
Fair value measurements on a recurring basis | Real estate
Fair value measurements on a recurring basis by asset class and level of input
Other investments	4,338		4,412
Other investments:
Contributions made to the funds	0		0
Distributions received from the funds	300		900
Unfunded commitments	$ 0		$ 300
Fair value measurements on a recurring basis | Real estate | Minimum
Other investments:
Underlying assets, liquidation period from inception of fund (in years)	5 years		5 years
Fair value measurements on a recurring basis | Real estate | Maximum
Other investments:
Underlying assets, liquidation period from inception of fund (in years)	10 years		10 years
Fair value measurements on a recurring basis | Level 1
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	$ 0		$ 5,950
Total	0		5,950
Fair value measurements on a recurring basis | Level 1 | Fixed maturities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 1 | U.S. treasury
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 1 | Government sponsored entities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities			0
Fair value measurements on a recurring basis | Level 1 | States & political subdivisions
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 1 | Foreign government securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0
Fair value measurements on a recurring basis | Level 1 | Corporate debt securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 1 | Residential mortgage-backed securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 1 | Commercial mortgage-backed securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 1 | Collateralized debt obligations
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 1 | Other debt securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 1 | Common stock
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities			5,950
Fair value measurements on a recurring basis | Level 2
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	741,351		697,989
Total	741,351		697,989
Fair value measurements on a recurring basis | Level 2 | Fixed maturities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	741,351		697,989
Fair value measurements on a recurring basis | Level 2 | U.S. treasury
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	11,834		5,031
Fair value measurements on a recurring basis | Level 2 | Government sponsored entities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities			2,026
Fair value measurements on a recurring basis | Level 2 | States & political subdivisions
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	261,966		253,132
Fair value measurements on a recurring basis | Level 2 | Foreign government securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	507
Fair value measurements on a recurring basis | Level 2 | Corporate debt securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	338,457		313,596
Fair value measurements on a recurring basis | Level 2 | Residential mortgage-backed securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	25,719		16,102
Fair value measurements on a recurring basis | Level 2 | Commercial mortgage-backed securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	34,331		36,849
Fair value measurements on a recurring basis | Level 2 | Collateralized debt obligations
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	62,381		69,253
Fair value measurements on a recurring basis | Level 2 | Other debt securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	6,156		2,000
Fair value measurements on a recurring basis | Level 2 | Common stock
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities			0
Fair value measurements on a recurring basis | Level 3
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	7,915		9,352
Total	7,915		9,352
Fair value measurements on a recurring basis | Level 3 | Fixed maturities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	7,915		9,352
Fair value measurements on a recurring basis | Level 3 | U.S. treasury
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 3 | Government sponsored entities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities			0
Fair value measurements on a recurring basis | Level 3 | States & political subdivisions
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 3 | Foreign government securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0
Fair value measurements on a recurring basis | Level 3 | Corporate debt securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	7,915		9,352
Fair value measurements on a recurring basis | Level 3 | Residential mortgage-backed securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 3 | Commercial mortgage-backed securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 3 | Collateralized debt obligations
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	0		0
Fair value measurements on a recurring basis | Level 3 | Other debt securities
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities	$ 0		0
Fair value measurements on a recurring basis | Level 3 | Common stock
Fair value measurements on a recurring basis by asset class and level of input
Available-for-sale securities			$ 0

Fair Value (Details 2)

Fair Value (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair value transfers due to changes in available market observable inputs
Transfers from level 1 to level 2	$ 0	$ 0	$ 0	$ 0
Transfers from level 2 to level 1	0	0	0	0
Level 3
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	9,295	11,054	9,352	8,646
Included in earnings	24	22	3	71
Included in other comprehensive income	(60)	45	(108)	117
Purchases	539	6,217	4,520	20,609
Sales	(1,240)	(318)	(4,372)	(978)
Transfers into Level 3	2,633	4,628	8,444	7,584
Transfers out of Level 3	(3,276)	(6,338)	(9,924)	(20,739)
Ending balance	7,915	15,310	7,915	15,310
Level 3 | Available-for-sale securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	9,295	11,054	9,352	8,646
Included in earnings	24	22	3	71
Included in other comprehensive income	(60)	45	(108)	117
Purchases	539	6,217	4,520	20,609
Sales	(1,240)	(318)	(4,372)	(978)
Transfers into Level 3	2,633	4,628	8,444	7,584
Transfers out of Level 3	(3,276)	(6,338)	(9,924)	(20,739)
Ending balance	7,915	15,310	7,915	15,310
Level 3 | Fixed maturities | Available-for-sale securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	9,295	11,054	9,352	8,646
Included in earnings	24	22	3	71
Included in other comprehensive income	(60)	45	(108)	117
Purchases	539	6,217	4,520	20,609
Sales	(1,240)	(318)	(4,372)	(978)
Transfers into Level 3	2,633	4,628	8,444	7,584
Transfers out of Level 3	(3,276)	(6,338)	(9,924)	(20,739)
Ending balance	7,915	15,310	7,915	15,310
Level 3 | Corporate debt securities | Available-for-sale securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	9,295	8,851	9,352	69
Included in earnings	24	22	3	67
Included in other comprehensive income	(60)	38	(108)	119
Purchases	539	3,217	4,520	11,887
Sales	(1,240)	(318)	(4,372)	(924)
Transfers into Level 3	2,633	2,514	8,444	5,470
Transfers out of Level 3	(3,276)	(4,135)	(9,924)	(6,499)
Ending balance	$ 7,915	10,189	$ 7,915	10,189
Level 3 | Commercial mortgage-backed securities | Available-for-sale securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance		1,003		0
Included in earnings		0		0
Included in other comprehensive income		0		3
Purchases		0		1,000
Sales		0		0
Transfers into Level 3		0		0
Transfers out of Level 3		(1,003)		(1,003)
Ending balance		0		0
Level 3 | Collateralized debt obligations | Available-for-sale securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance		1,200		8,577
Included in earnings		0		4
Included in other comprehensive income		7		(5)
Purchases		3,000		7,722
Sales		0		(54)
Transfers into Level 3		2,114		2,114
Transfers out of Level 3		(1,200)		(13,237)
Ending balance		$ 5,121		$ 5,121

Fair Value (Details 3)

Fair Value (Details 3) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair value by pricing source
Available-for-sale securities	$ 749,266	$ 713,291
Fair value measurements on a recurring basis
Fair value by pricing source
Available-for-sale securities	749,266	713,291
Total	753,604	717,703
Fair value measurements on a recurring basis | Fixed maturities
Fair value by pricing source
Available-for-sale securities	749,266	707,341
Fair value measurements on a recurring basis | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	749,266
Fair value measurements on a recurring basis | Real estate
Fair value by pricing source
Other investments	4,338	4,412
Fair value measurements on a recurring basis | Real estate | Priced via unobservable inputs
Fair value by pricing source
Other investments	4,338
Fair value measurements on a recurring basis | Level 1
Fair value by pricing source
Available-for-sale securities	0	5,950
Total	0	5,950
Fair value measurements on a recurring basis | Level 1 | Fixed maturities
Fair value by pricing source
Available-for-sale securities	0	0
Fair value measurements on a recurring basis | Level 1 | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	0
Fair value measurements on a recurring basis | Level 2
Fair value by pricing source
Available-for-sale securities	741,351	697,989
Total	741,351	697,989
Fair value measurements on a recurring basis | Level 2 | Fixed maturities
Fair value by pricing source
Available-for-sale securities	741,351	697,989
Fair value measurements on a recurring basis | Level 2 | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	741,351
Fair value measurements on a recurring basis | Level 3
Fair value by pricing source
Available-for-sale securities	7,915	9,352
Total	7,915	9,352
Fair value measurements on a recurring basis | Level 3 | Non-binding broker quotes classified within Level 3
Fair value by pricing source
Available-for-sale securities	7,900
Fair value measurements on a recurring basis | Level 3 | Fixed maturities
Fair value by pricing source
Available-for-sale securities	7,915	$ 9,352
Fair value measurements on a recurring basis | Level 3 | Fixed maturities | Priced via pricing services
Fair value by pricing source
Available-for-sale securities	7,915
Fair value measurements on a nonrecurring basis
Fair value by pricing source
Total	$ 0

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Available-for-sale securities
Amortized cost, fixed maturities	$ 740,809
Amortized cost	740,809	$ 708,555
Gross unrealized gains	10,737	9,899
Gross unrealized losses	2,280	5,163
Estimated fair value, fixed maturities	749,266
Estimated fair value	749,266	713,291
Fixed maturities
Available-for-sale securities
Amortized cost, fixed maturities	740,809	702,403
Gross unrealized gains, fixed maturities	10,737	9,899
Gross unrealized losses, fixed maturities	2,280	4,961
Estimated fair value, fixed maturities	749,266	707,341
U.S. treasury
Available-for-sale securities
Amortized cost, fixed maturities	11,878	5,093
Gross unrealized gains, fixed maturities	0	0
Gross unrealized losses, fixed maturities	44	62
Estimated fair value, fixed maturities	11,834	5,031
Government sponsored entities
Available-for-sale securities
Amortized cost, fixed maturities		2,004
Gross unrealized gains, fixed maturities		22
Gross unrealized losses, fixed maturities		0
Estimated fair value, fixed maturities		2,026
States & political subdivisions
Available-for-sale securities
Amortized cost, fixed maturities	254,835	249,312
Gross unrealized gains, fixed maturities	7,809	6,113
Gross unrealized losses, fixed maturities	678	2,293
Estimated fair value, fixed maturities	261,966	253,132
Foreign government securities
Available-for-sale securities
Amortized cost, fixed maturities	501
Gross unrealized gains, fixed maturities	6
Gross unrealized losses, fixed maturities	0
Estimated fair value, fixed maturities	507
Corporate debt securities
Available-for-sale securities
Amortized cost, fixed maturities	345,003	321,041
Gross unrealized gains, fixed maturities	2,201	3,293
Gross unrealized losses, fixed maturities	832	1,386
Estimated fair value, fixed maturities	346,372	322,948
Residential mortgage-backed securities
Available-for-sale securities
Amortized cost, fixed maturities	25,388	16,232
Gross unrealized gains, fixed maturities	404	61
Gross unrealized losses, fixed maturities	73	191
Estimated fair value, fixed maturities	25,719	16,102
Commercial mortgage-backed securities
Available-for-sale securities
Amortized cost, fixed maturities	34,892	37,723
Gross unrealized gains, fixed maturities	73	59
Gross unrealized losses, fixed maturities	634	933
Estimated fair value, fixed maturities	34,331	36,849
Collateralized debt obligations
Available-for-sale securities
Amortized cost, fixed maturities	62,193	68,998
Gross unrealized gains, fixed maturities	207	351
Gross unrealized losses, fixed maturities	19	96
Estimated fair value, fixed maturities	62,381	69,253
Other debt securities
Available-for-sale securities
Amortized cost, fixed maturities	6,119	2,000
Gross unrealized gains, fixed maturities	37	0
Gross unrealized losses, fixed maturities	0	0
Estimated fair value, fixed maturities	$ 6,156	2,000
Common stock
Available-for-sale securities
Amortized cost, equity securities		6,152
Gross unrealized gains, equity securities		0
Gross unrealized losses, equity securities		202
Estimated fair value, equity securities		$ 5,950

Investments (Details 2)

Investments (Details 2) $ in Thousands	Sep. 30, 2017USD ($)
Amortized cost
Due in one year or less	$ 65,085
Due after one year through five years	332,904
Due after five years through ten years	239,042
Due after ten years	103,778
Amortized cost, fixed maturities	740,809
Estimated fair value
Due in one year or less	65,208
Due after one year through five years	337,986
Due after five years through ten years	242,425
Due after ten years	103,647
Estimated fair value, fixed maturities	$ 749,266

Investments (Details 3)

Investments (Details 3) $ in Thousands	Sep. 30, 2017USD ($)Holdings	Dec. 31, 2016USD ($)Holdings
Fair value
Less than 12 months	$ 204,713	$ 269,475
12 months or longer	44,021	22,193
Total	248,734	291,668
Unrealized losses
Less than 12 months	1,256	4,116
12 months or longer	1,024	1,047
Total	$ 2,280	$ 5,163
No. of holdings | Holdings	324	253
Investment grade
Fair value
Less than 12 months	$ 152,341	$ 239,041
12 months or longer	42,020	16,061
Total	194,361	255,102
Unrealized losses
Less than 12 months	745	3,605
12 months or longer	533	399
Total	$ 1,278	$ 4,004
No. of holdings | Holdings	113	136
Non-investment grade
Fair value
Less than 12 months	$ 52,372	$ 24,484
12 months or longer	2,001	6,132
Total	54,373	30,616
Unrealized losses
Less than 12 months	511	309
12 months or longer	491	648
Total	$ 1,002	$ 957
No. of holdings | Holdings	211	116
Fixed maturities
Fair value
Less than 12 months	$ 204,713	$ 263,525
12 months or longer	44,021	22,193
Total	248,734	285,718
Unrealized losses
Less than 12 months	1,256	3,914
12 months or longer	1,024	1,047
Total	$ 2,280	$ 4,961
No. of holdings | Holdings	324	252
U.S. treasury
Fair value
Less than 12 months	$ 11,835	$ 5,031
12 months or longer	0	0
Total	11,835	5,031
Unrealized losses
Less than 12 months	44	62
12 months or longer	0	0
Total	$ 44	$ 62
No. of holdings | Holdings	4	1
States & political subdivisions
Fair value
Less than 12 months	$ 49,278	$ 84,611
12 months or longer	7,280	0
Total	56,558	84,611
Unrealized losses
Less than 12 months	449	2,293
12 months or longer	229	0
Total	$ 678	$ 2,293
No. of holdings | Holdings	26	40
Corporate debt securities
Fair value
Less than 12 months	$ 108,828	$ 112,453
12 months or longer	19,951	8,692
Total	128,779	121,145
Unrealized losses
Less than 12 months	619	987
12 months or longer	213	399
Total	$ 832	$ 1,386
No. of holdings | Holdings	255	155
Residential mortgage-backed securities
Fair value
Less than 12 months	$ 5,553	$ 7,451
12 months or longer	5,771	4,974
Total	11,324	12,425
Unrealized losses
Less than 12 months	19	60
12 months or longer	54	131
Total	$ 73	$ 191
No. of holdings | Holdings	10	13
Commercial mortgage-backed securities
Fair value
Less than 12 months	$ 12,793	$ 26,509
12 months or longer	11,019	4,319
Total	23,812	30,828
Unrealized losses
Less than 12 months	106	437
12 months or longer	528	496
Total	$ 634	$ 933
No. of holdings | Holdings	21	28
Collateralized debt obligations
Fair value
Less than 12 months	$ 16,426	$ 27,470
12 months or longer	0	4,208
Total	16,426	31,678
Unrealized losses
Less than 12 months	19	75
12 months or longer	0	21
Total	$ 19	$ 96
No. of holdings | Holdings	8	15
Common stock
Fair value
Less than 12 months		$ 5,950
12 months or longer		0
Total		5,950
Unrealized losses
Less than 12 months		202
12 months or longer		0
Total		$ 202
No. of holdings | Holdings		1

Investments (Details 4)

Investments (Details 4) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Investment income from portfolios
Total investment income	$ 6,170	$ 5,661	$ 19,259	$ 15,772
Less: investment expenses	200	330	1,075	888
Net investment income	5,970	5,331	18,184	14,884
Fixed maturities
Investment income from portfolios
Total investment income	4,234	5,245	16,358	14,629
Equity securities
Investment income from portfolios
Total investment income	0	50	49	132
Cash equivalents and other
Investment income from portfolios
Total investment income	$ 1,936	$ 366	$ 2,852	$ 1,011

Investments (Details 5)

Investments (Details 5) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Realized investment gains (losses)
Net realized investment gains	$ 899	$ 718	$ 1,539	$ 29
Other-than-temporary impairments on investments
Other-than-temporary impairments on investments	0	0	(182)	(345)
Portion recognized in other comprehensive income	0	0	0	0
Net impairment losses recognized in earnings	0	0	(182)	(345)
Fixed maturities
Available-for-sale securities:
Gross realized gains	1,621	603	2,708	1,175
Gross realized losses	(722)	(27)	(1,116)	(1,819)
Net realized gains (losses)	899	576	1,592	(644)
Other-than-temporary impairments on investments
Other-than-temporary impairments on investments	0	0	(182)	(345)
Equity securities
Available-for-sale securities:
Gross realized losses	0	0	(145)	(34)
Net realized gains (losses)	0	0	(145)	(34)
Common stock
Trading securities:
Gross realized gains	0	121	0	707
Increases in fair value	0	21	0	0
Net realized gains	0	142	0	707
Other investments
Miscellaneous:
Gross realized gains	0	0	94	0
Gross realized losses	0	0	(2)	0
Net realized gains	$ 0	$ 0	$ 92	$ 0

Investments (Details 6)

Investments (Details 6) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Investments in limited partnerships
Equity in earnings (losses) of limited partnerships	$ 1,537	$ (1,723)	$ 1,899	$ (279)
Equity method of accounting
Investments in limited partnerships
Equity in earnings (losses) of limited partnerships	1,305	(1,778)	1,704	(436)
Fair value option
Investments in limited partnerships
Equity in earnings (losses) of limited partnerships	$ 232	$ 55	$ 195	$ 157

Investments (Details 7)

Investments (Details 7) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investments in limited partnerships
Asset recorded	$ 49,451	$ 58,159
Private equity
Investments in limited partnerships
Asset recorded	33,478	35,228
Mezzanine debt
Investments in limited partnerships
Asset recorded	4,797	6,010
Real estate
Investments in limited partnerships
Asset recorded	6,838	12,509
Fair value option | Real estate
Investments in limited partnerships
Asset recorded	$ 4,338	$ 4,412

Borrowing Arrangements (Details

Borrowing Arrangements (Details) - Revolving line of credit $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)
Bank Line of Credit
Maximum borrowing capacity under the bank revolving line of credit	$ 100
Maximum letter of credit sublimit under the bank revolving line of credit	$ 25
Expiration date of the bank revolving line of credit	Nov. 3, 2020
Available borrowing capacity under the bank revolving line of credit, due to outstanding letters of credit	$ 99.1
Outstanding amount of letters of credit under the bank revolving line of credit	0.9
Available amount of letters of credit under the bank revolving line of credit	24.1
Borrowings outstanding under the bank revolving line of credit	0
Fair value of bonds pledged as collateral on the bank revolving line of credit	$ 109.5

Borrowing Arrangements (Detai39

Borrowing Arrangements (Details 2) - Secured debt - USD ($) $ in Millions	Jun. 01, 2018	Dec. 01, 2017	Jun. 01, 2017	Dec. 01, 2016	Sep. 30, 2017
Term loan credit facility
Amount of senior secured draw term loan credit facility					$ 100
Scheduled draws on the credit facility			$ 25	$ 25
Repayment period of credit facility (in years)					28 years
Fixed interest rate of credit facility (as a percent)					4.35%
Quarterly commitment fee on the unused portion of the credit facility (as a percent)					0.08%
Total amount drawn on the credit facility					$ 50
Fair value of bonds pledged as collateral on the credit facility					109.7
Estimated fair value of the credit facility					47.9
Principal payments due in 2019					1.9
Principal payments due in 2020					2
Principal payments due in 2021					2
Principal payments due in 2022					2.1
Principal payments due in 2023 and thereafter					$ 92
Scenario, Forecast [Member]
Term loan credit facility
Scheduled draws on the credit facility	$ 25	$ 25

Postretirement Benefits (Detail

Postretirement Benefits (Details) - Pension plans - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Mar. 31, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Cost of pension plans:
Service cost for benefits earned	$ 7,777		$ 7,050	$ 23,330	$ 21,150
Interest cost on benefits obligation	8,569		8,281	25,706	24,844
Expected return on plan assets	(10,317)		(9,880)	(30,950)	(29,640)
Prior service cost amortization	218		174	654	522
Net actuarial loss amortization	2,325		2,029	6,975	6,084
Pension plan cost	8,572		$ 7,654	$ 25,715	$ 22,960
Erie Insurance Exchange (EIE)
Postretirement Benefits
Postretirement annual benefit expense reimbursed to Indemnity from the Exchange (as a percent)				58.00%
Qualified plan | Funded plan
Postretirement Benefits
Employer contribution	20,000	$ 19,000
Qualified plan | Funded plan | Erie Family Life Insurance Company (EFL)
Postretirement Benefits
Contingent liability for amount of nonparticipating annuity contracts the employee pension plan purchased from EFL	$ 19,700			$ 19,700

Income Taxes (Details)

Income Taxes (Details)	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Statutory federal tax rate applied to pretax income (as a percent)	35.00%

Capital Stock (Details)

Capital Stock (Details) - Class B - shares	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Common Stock
Ratio for converting shares of Class B common stock into shares of Class A common stock (as a percent)	2400.00%	2400.00%
Class B common stock shares converted into Class A common stock shares (in shares)	0	0

Capital Stock (Details 2)

Capital Stock (Details 2) - Class A - USD ($) $ / shares in Units, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Oct. 31, 2011
Shares purchased outside of stock repurchase program
Total cost of shares purchased outside of publicly announced stock repurchase program	$ 7	$ 1.5
Performance shares
Shares purchased outside of stock repurchase program
Shares purchased outside of publicly announced stock repurchase program for share-based compensation awards (in shares)	58,129	15,093
Equity compensation plan
Shares purchased outside of stock repurchase program
Total cost of shares purchased outside of publicly announced stock repurchase program	$ 0.4
Average price per share for shares purchased (in dollars per share)	$ 111.55
Equity compensation plan | Performance shares
Shares purchased outside of stock repurchase program
Shares purchased outside of publicly announced stock repurchase program for share-based compensation awards (in shares)	3,785
Stock compensation plan for outside directors
Shares purchased outside of stock repurchase program
Total cost of shares purchased outside of publicly announced stock repurchase program	$ 0.9	$ 0.7
Average price per share for shares purchased (in dollars per share)	$ 121.46	$ 99.23
Stock compensation plan for outside directors | Performance shares
Shares purchased outside of stock repurchase program
Shares purchased outside of publicly announced stock repurchase program for share-based compensation awards (in shares)	7,460	7,432
Long-term incentive plan
Shares purchased outside of stock repurchase program
Total cost of shares purchased outside of publicly announced stock repurchase program	$ 5.7	$ 0.8
Average price per share for shares purchased (in dollars per share)	$ 122.40	$ 98.20
Long-term incentive plan | Performance shares
Shares purchased outside of stock repurchase program
Shares purchased outside of publicly announced stock repurchase program for share-based compensation awards (in shares)	46,884	7,661
Stock repurchase program
Stock repurchases
Amount of authorized stock repurchases approved for continuation under the current program			$ 150
Shares repurchased under stock repurchase program (in shares)	0	0
Approximate amount of repurchase authority remaining under the current stock repurchase program	$ 17.8

Accumulated Other Comprehensi44

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated other comprehensive income (loss), net of tax
AOCI (loss), beginning of period			$ (121,381)
OCI (loss)	$ (167)	$ 355	2,446	$ 6,846
AOCI (loss), end of period	(118,935)		(118,935)
Investment securities:
Accumulated other comprehensive income (loss), before tax
AOCI (loss), beginning of period	7,974	13,875	3,954	3,888
OCI before reclassifications	643	1,121	5,029	9,509
Realized investment (gains) losses	(899)	(576)	(1,447)	678
Impairment losses			182	345
OCI (loss)	(256)	545	3,764	10,532
AOCI (loss), end of period	7,718	14,420	7,718	14,420
Accumulated other comprehensive income (loss), tax
AOCI (loss), beginning of period	2,791	4,857	1,384	1,361
OCI before reclassifications	225	392	1,760	3,328
Realized investment (gains) losses	(314)	(202)	(506)	237
Impairment losses			64	121
OCI (loss)	(89)	190	1,318	3,686
AOCI (loss), end of period	2,702	5,047	2,702	5,047
Accumulated other comprehensive income (loss), net of tax
AOCI (loss), beginning of period	5,183	9,018	2,570	2,527
OCI before reclassifications	418	729	3,269	6,181
Realized investment (gains) losses	(585)	(374)	(941)	441
Impairment losses			118	224
OCI (loss)	(167)	355	2,446	6,846
AOCI (loss), end of period	5,016	9,373	5,016	9,373
Pension and other postretirement plans:
Accumulated other comprehensive income (loss), before tax
AOCI (loss), beginning of period	(190,695)	(152,910)	(190,695)	(152,910)
AOCI (loss), end of period	(190,695)	(152,910)	(190,695)	(152,910)
Accumulated other comprehensive income (loss), tax
AOCI (loss), beginning of period	(66,744)	(53,519)	(66,744)	(53,519)
AOCI (loss), end of period	(66,744)	(53,519)	(66,744)	(53,519)
Accumulated other comprehensive income (loss), net of tax
AOCI (loss), beginning of period	(123,951)	(99,391)	(123,951)	(99,391)
AOCI (loss), end of period	(123,951)	(99,391)	(123,951)	(99,391)
Total
Accumulated other comprehensive income (loss), before tax
AOCI (loss), beginning of period	(182,721)	(139,035)	(186,741)	(149,022)
OCI (loss)	(256)	545	3,764	10,532
OCI (loss)	0	0	0	0
OCI (loss)	(256)	545	3,764	10,532
AOCI (loss), end of period	(182,977)	(138,490)	(182,977)	(138,490)
Accumulated other comprehensive income (loss), tax
AOCI (loss), beginning of period	(63,953)	(48,662)	(65,360)	(52,158)
OCI (loss)	(89)	190	1,318	3,686
OCI (loss)	0	0	0	0
OCI (loss)	(89)	190	1,318	3,686
AOCI (loss), end of period	(64,042)	(48,472)	(64,042)	(48,472)
Accumulated other comprehensive income (loss), net of tax
AOCI (loss), beginning of period	(118,768)	(90,373)	(121,381)	(96,864)
OCI (loss)	(167)	355	2,446	6,846
OCI (loss)	0	0	0	0
OCI (loss)	(167)	355	2,446	6,846
AOCI (loss), end of period	$ (118,935)	$ (90,018)	$ (118,935)	$ (90,018)

Related Party (Details)

Related Party (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Related Party Transactions
Rent expense on office space leased from Exchange			$ 14.3
Reimbursements from the Exchange related to rent expense			$ 4.9
Scenario, Forecast [Member]
Related Party Transactions
Rent expense on office space leased from Exchange		$ 17.4
Erie Insurance Exchange (EIE)
Related Party Transactions
Number of field office facilities leased from the Exchange	3

Concentrations of Credit Risk (

Concentrations of Credit Risk (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Concentrations of credit risk from unsecured receivables
Receivables from Erie Insurance Exchange and affiliates	$ 428,500	$ 378,540

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)
Contractual commitments
Represents the entity's maximum contractual commitments to invest in its limited partnership investments	$ 16.4
Description of commitment: contractual commitment to invest in limited partnership investments	Contractual commitments to invest in limited partnership investments, consisting of private equity securities, mezzanine debt securities, and real estate activities.
Private equity
Contractual commitments
Represents the entity's maximum contractual commitments to invest in its limited partnership investments	$ 6.6
Mezzanine debt
Contractual commitments
Represents the entity's maximum contractual commitments to invest in its limited partnership investments	8.2
Real estate
Contractual commitments
Represents the entity's maximum contractual commitments to invest in its limited partnership investments	$ 1.6