Selective Insurance (SIGI) 10-Q 2 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 19, 2019
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Entity Registrant Name	SELECTIVE INSURANCE GROUP INC
Entity Central Index Key	0000230557
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock , Shares Outstanding		59,231,319
Entity Emerging Growth Company	false
Entity Small Business	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
ASSETS
Fixed income securities, held-to-maturity – at carrying value (fair value: $37,942 – 2019; $38,317 – 2018)	$ 36,493	$ 37,110
Fixed income securities, available-for-sale – at fair value (amortized cost: $5,463,273 – 2019; $5,270,798 – 2018)	5,567,358	5,273,100
Equity securities – at fair value (cost: $143,376 – 2019; $138,144 – 2018)	163,016	147,639
Short-term investments (at cost which approximates fair value)	290,653	323,864
Other investments	176,225	178,938
Total investments (Note 4 and 6)	6,233,745	5,960,651
Cash	516	505
Restricted cash	9,998	16,414
Interest and dividends due or accrued	42,147	41,620
Premiums receivable, net of allowance for uncollectible accounts of: $9,600 – 2019; $9,400 – 2018	814,914	770,518
Reinsurance recoverable, net of allowance for uncollectible accounts of: $4,100 – 2019; $4,500 – 2018	553,206	549,172
Prepaid reinsurance premiums	155,700	157,723
Deferred federal income tax	32,130	53,540
Property and equipment – at cost, net of accumulated depreciation and amortization of: $216,071 – 2019; $211,657 – 2018	68,660	65,248
Deferred policy acquisition costs	260,754	252,612
Goodwill	7,849	7,849
Other assets	103,142	76,877
Total assets	8,282,761	7,952,729
Liabilities And Stockholders' Equity
Reserve for loss and loss expense (Note 8)	3,966,509	3,893,868
Unearned premiums	1,470,283	1,431,932
Long-term debt	550,104	439,540
Current federal income tax	13,551	1,302
Accrued salaries and benefits	78,177	116,706
Other liabilities	278,915	277,579
Total liabilities	6,357,539	6,160,927
Stockholders' Equity:
Preferred stock of $0 par value per share: Authorized shares: 5,000,000; no shares issued or outstanding	0	0
Common stock of $2 par value per share: Authorized shares: 360,000,000; Issued: 103,225,716 – 2019; 102,848,394 – 2018	206,451	205,697
Additional paid-in capital	398,881	390,315
Retained earnings	1,908,119	1,858,414
Accumulated other comprehensive income (loss) (Note 11)	3,024	(77,956)
Treasury stock – at cost (shares: 44,002,811 – 2019; 43,899,840 – 2018)	(591,253)	(584,668)
Total stockholders' equity	1,925,222	1,791,802
Commitments and contingencies
Total liabilities and stockholders' equity	$ 8,282,761	$ 7,952,729

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fixed income securities, held-to-maturity, fair value	$ 37,942	$ 38,317
Fixed income securities, available-for-sale, amortized cost	5,463,273	5,270,798
Equity securities, cost	143,376	138,144
Premiums receivable, allowance for uncollectible accounts	9,600	9,400
Reinsurance recoverable, allowance for uncollectible accounts	4,100	4,500
Property and equipment - at cost, accumulated depreciation and amortization	$ 216,071	$ 211,657
Preferred stock, par value per share	$ 0	$ 0
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share	$ 2	$ 2
Common stock, shares authorized	360,000,000	360,000,000
Common stock, shares issued	103,225,716	102,848,394
Treasury stock - at cost, shares	44,002,811	43,899,840

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Net premiums earned	$ 632,573	$ 591,828
Net investment income earned	50,618	43,231
Net realized and unrealized gains (losses):
Net realized investment gains on disposals	3,444	4,731
Other-than-temporary impairments	(104)	(1,212)
Unrealized gains (losses) on equity securities	10,111	(14,068)
Total net realized and unrealized gains (losses)	13,451	(10,549)
Other income	2,320	2,179
Total revenues	698,962	626,689
Expenses:
Loss and loss expense incurred	386,579	384,941
Amortization of deferred policy acquisition costs	129,674	121,093
Other insurance expenses	85,079	83,240
Interest expense	11,526	6,152
Corporate expenses	12,410	11,332
Total expenses	625,268	606,758
Income before federal income tax	73,694	19,931
Federal income tax expense:
Current	12,581	433
Deferred	(235)	573
Total federal income tax expense	12,346	1,006
Net income	$ 61,348	$ 18,925
Earnings per share:
Basic net income	$ 1.04	$ 0.32
Diluted net income	$ 1.02	$ 0.32

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net income	$ 61,348	$ 18,925
Unrealized holding gains (losses) arising during period	81,313	(67,398)
Amounts reclassified into net income: Held-to-maturity securities	(7)	(10)
Amounts reclassified into net income: Realized (gains) losses on disposals and OTTI of available-for-sale securities	(851)	3,594
Total unrealized gains (losses) on investment securities	80,455	(63,814)
Amount reclassified into net income: Net actuarial loss	525	420
Total defined benefit pension and post-retirement plans	525	420
Other comprehensive income (loss)	80,980	(63,394)
Comprehensive income (loss)	$ 142,328	$ (44,469)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional paid-in capital [Member]	Retained Earnings [Member]	Accumulated other comprehensive income (loss) [Member]	Treasury stock [Member]
Balance at beginning of year, as adjusted				$ 1,723,632	$ (4,849)
Beginning of year at Dec. 31, 2017		$ 204,569	$ 367,717	1,698,613	20,170	$ (578,112)
Dividend reinvestment plan (shares: 5,694 – 2019; 6,298 – 2018)		13	353
Stock purchase and compensation plans (shares: 371,628 – 2019; 349,255 – 2018)		698	7,085
Net income	$ 18,925			18,925
Dividends to stockholders ($0.20 per share – 2019; $0.18 per share – 2018)				(10,725)
Other comprehensive income (loss)	(63,394)				(63,394)
Acquisition of treasury stock (shares: 102,971 – 2019; 103,170 – 2018)						(6,116)
End of period at Mar. 31, 2018	1,659,796	205,280	375,155	1,731,832	(68,243)	(584,228)
Cumulative effect of new accounting principle in period of adoption | Accounting Standards Update 2016-01 [Member]				30,726	(30,726)
Cumulative effect of new accounting principle in period of adoption | Accounting Standards Update 2018-02 [Member]				(5,707)	5,707
Cumulative effect of new accounting principle in period of adoption | Accounting Standards Update 2016-02 [Member]				0
Balance at beginning of year, as adjusted				1,858,756	(77,956)
Beginning of year at Dec. 31, 2018	1,791,802	205,697	390,315	1,858,414	(77,956)	(584,668)
Dividend reinvestment plan (shares: 5,694 – 2019; 6,298 – 2018)		11	365
Stock purchase and compensation plans (shares: 371,628 – 2019; 349,255 – 2018)		743	8,201
Net income	61,348			61,348
Dividends to stockholders ($0.20 per share – 2019; $0.18 per share – 2018)				(11,985)
Other comprehensive income (loss)	80,980				80,980
Acquisition of treasury stock (shares: 102,971 – 2019; 103,170 – 2018)						(6,585)
End of period at Mar. 31, 2019	$ 1,925,222	$ 206,451	$ 398,881	1,908,119	3,024	$ (591,253)
Cumulative effect of new accounting principle in period of adoption | Accounting Standards Update 2016-01 [Member]				0	0
Cumulative effect of new accounting principle in period of adoption | Accounting Standards Update 2018-02 [Member]				0	$ 0
Cumulative effect of new accounting principle in period of adoption | Accounting Standards Update 2016-02 [Member]				$ 342

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Dividend reinvestment plan, shares	5,694	6,298
Stock purchase and compensation plans, shares	371,628	349,255
Dividends to stockholders, per share	$ 0.20	$ 0.18
Acquisition of treasury stock, shares	102,971	103,170
Preferred stock, par value per share	$ 0	$ 0
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Series A Preferred Stock [Member]
Preferred stock, par value per share	$ 0	$ 0
Preferred stock, shares authorized	300,000	300,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flow - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating Activities
Net income	$ 61,348	$ 18,925
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	16,278	11,200
Stock-based compensation expense	6,677	5,820
Undistributed gains of equity method investments	(971)	(881)
Distributions in excess of current year income of equity method investments	1,771	1,346
Loss on disposal of fixed assets	0	29
Net realized and unrealized (gains) losses	(13,451)	10,549
Changes in assets and liabilities:
Increase in reserve for loss and loss expense, net of reinsurance recoverable	68,607	54,766
Increase in unearned premiums, net of prepaid reinsurance	40,374	32,732
Decrease in net federal income taxes	12,044	3,616
Increase in premiums receivable	(44,396)	(19,284)
Increase in deferred policy acquisition costs	(8,142)	(4,237)
Increase in interest and dividends due or accrued	(491)	(864)
Decrease in accrued salaries and benefits	(38,529)	(41,363)
Increase in other assets	(8,711)	(9,672)
Decrease in other liabilities	(45,769)	(70,387)
Net cash provided by (used in) operating activities	46,639	(7,705)
Investing Activities
Purchase of fixed income securities, available-for-sale	(474,962)	(875,016)
Purchase of equity securities	(6,702)	(38,273)
Purchase of other investments	(12,178)	(13,471)
Purchase of short-term investments	(2,416,285)	(754,524)
Sale of fixed income securities, available-for-sale	218,411	675,396
Sale of short-term investments	2,449,725	737,097
Redemption and maturities of fixed income securities, held-to-maturity	579	484
Redemption and maturities of fixed income securities, available-for-sale	86,572	160,514
Sale of equity securities	3,721	40,740
Sale of other investments	4,995	3,497
Distributions from other investments	11,350	6,221
Purchase of property and equipment	(7,955)	(2,120)
Net cash used in investing activities	(142,729)	(59,455)
Financing Activities
Dividends to stockholders	(11,462)	(10,203)
Acquisition of treasury stock	(6,585)	(6,116)
Net proceeds from stock purchase and compensation plans	1,760	1,435
Proceeds from borrowings	341,256	130,000
Repayments of borrowings	(235,000)	(75,000)
Repayments of finance lease obligations	(284)
Repayments of capital lease obligations		(734)
Net cash provided by financing activities	89,685	39,382
Net decrease in cash and restricted cash	(6,405)	(27,778)
Cash and restricted cash, beginning of year	16,919	44,710
Cash and restricted cash, end of period	$ 10,514	$ 16,932

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2019
Basis of Presentation And Significant Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation As used herein, the "Company,” “we,” “us,” or “our” refers to Selective Insurance Group, Inc. (the "Parent"), and its subsidiaries, except as expressly indicated or unless the context otherwise requires. Our interim unaudited consolidated financial statements (“Financial Statements”) have been prepared by us in conformity with U.S. generally accepted accounting principles (“GAAP”) and the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) regarding interim financial reporting. The preparation of the Financial Statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported financial statement balances, as well as the disclosure of contingent assets and liabilities. Actual results could differ from those estimates. All significant intercompany accounts and transactions between the Parent and its subsidiaries are eliminated in consolidation. Our Financial Statements reflect all adjustments that, in our opinion, are normal, recurring, and necessary for a fair presentation of our results of operations and financial condition. Our Financial Statements cover the first quarters ended March 31, 2019 (“ First Quarter 2019 ”) and March 31, 2018 (“ First Quarter 2018 ”). These Financial Statements do not include all of the information and disclosures required by GAAP and the SEC for audited annual financial statements. Additionally, results of operations for any interim period are not necessarily indicative of results for a full year. Consequently, our Financial Statements should be read in conjunction with the consolidated financial statements contained in our Annual Report on Form 10-K for the year ended December 31, 2018 (“ 2018 Annual Report”) filed with the SEC.

Accounting Pronouncements

Accounting Pronouncements	3 Months Ended
	Mar. 31, 2019
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Accounting Pronouncements	Adoption of Accounting Pronouncements The Financial Accounting Standards Board ("FASB") issued new leasing guidance through ASU 2016-02, Leases , which was issued in February 2016, as well as additional implementation guidance that was issued in 2018 and 2019 (collectively referred to as "ASU 2016-02"). ASU 2016-02 requires all lessees to recognize assets and liabilities on their balance sheets for the rights and obligations created by leases with terms longer than 12 months. For leases with a term of 12 months or less, an accounting policy election is allowed to recognize lease expense on a straight-line basis over the lease term. ASU 2016-02 allows for certain practical expedients, accounting policy elections, and a transition method election. We adopted practical expedients related to reassessing: (i) whether our existing contracts are, or contain, leases; (ii) lease classification for existing leases; and (iii) initial direct costs for existing leases. Additionally, we adopted accounting policy elections to: (i) aggregate lease and non-lease components of a contract into a single lease component; and (ii) expense short-term leases on a straight-line basis over the lease term. We adopted ASU 2016-02 effective January 1, 2019. See Note 12. "Leases" in this Form 10-Q for additional information regarding our leases and the impact of this guidance on our financial condition and results of operations. In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting ("ASU 2018-07"). The amendments in ASU 2018-07 expand the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. We adopted ASU 2018-07 in First Quarter 2019 and it did not have a material impact on our financial condition or results of operations. Pronouncements to be effective in the future In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (“ASU 2016-13”). ASU 2016-13 will change the way entities recognize impairment of financial assets by requiring immediate recognition of estimated credit losses expected to occur over the remaining life of many financial assets, including, among others, held-to-maturity ("HTM") debt securities, trade receivables, and reinsurance recoverables. This ASU will not impact the impairment accounting model for available-for-sale ("AFS") debt securities. ASU 2016-13 requires a valuation allowance to be calculated on these financial assets, and that they be presented on the financial statements net of the valuation allowance. The valuation allowance is a measurement of expected losses that is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. This methodology is referred to as the current expected credit loss model. ASU 2016-13 is effective for fiscal years beginning after December 15, 2019, including interim periods within those annual periods. We are currently evaluating the impact of this guidance on our financial condition and results of operations. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement: Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”). ASU 2018-13 modifies the disclosure requirements for fair value measurements. The modifications removed the following disclosure requirements: (i) the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy; (ii) the policy for timing of transfers between levels; and (iii) the valuation processes for Level 3 fair value measurements. This ASU added the following disclosure requirements: (i) the changes in unrealized gains and losses for the period included in other comprehensive income ("OCI") for recurring Level 3 fair value measurements held at the end of the reporting period; and (ii) the range and weighted average of significant observable inputs used to develop Level 3 fair value measurements. This update is effective for annual and interim periods beginning after December 15, 2019, with early adoption permitted. As the requirements of this literature are disclosure only, ASU 2018-13 will not impact our financial condition or results of operations. In August 2018, the FASB issued ASU 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General: Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans (“ASU 2018-14”). ASU 2018-14 modifies the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. These modifications include: (i) removing the requirement to disclose the amount in accumulated other comprehensive income ("AOCI") expected to be recognized as components of net periodic benefit cost over the next fiscal year; and (ii) adding the requirement to disclose an explanation of the reasons for significant gains or losses related to changes in the benefit obligation for the period. This update is effective for fiscal years ending after December 15, 2020, with early adoption permitted. As the requirements of this literature are disclosure only, ASU 2018-14 will not impact our financial condition or results of operations. In August 2018, the FASB issued ASU 2018-15, Intangibles - Goodwill and Other - Internal-Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract (“ASU 2018-15”). ASU 2018-15 aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This update is effective for annual and interim periods beginning after December 15, 2019, with early adoption permitted. We are currently evaluating the impact of this guidance on our financial condition or results of operations.

Statements of Cash Flow

Statements of Cash Flow	3 Months Ended
	Mar. 31, 2019
Supplemental Cash Flow Information [Abstract]
Statements of Cash Flow	Statements of Cash Flows Supplemental cash flow information was as follows: Quarter ended March 31, ($ in thousands) 2019 2018 Cash paid during the period for: Interest $ 4,477 3,455 Federal income tax — (2,807 ) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases 1 1,983 — Financing cash flows from finance leases 284 734 Non-cash items: Corporate actions related to fixed income securities, AFS 2 18,447 11,347 Assets acquired under operating lease arrangements 1 6,136 — Non-cash purchase of property and equipment 162 — 1 Upon adoption of ASU 2016-02, effective January 1, 2019, we are required to disclose cash paid for amounts included in the measurement of operating lease liabilities, as well as supplemental non-cash information on operating lease liabilities arising from obtaining operating lease assets. 2 Examples of such corporate actions include exchanges, non-cash acquisitions, and stock splits. The following table provides a reconciliation of cash and restricted cash reported within the Consolidated Balance Sheets that equate to the amount reported in the Consolidated Statements of Cash Flows: ($ in thousands) March 31, 2019 December 31, 2018 Cash $ 516 505 Restricted cash 9,998 16,414 Total cash and restricted cash shown in the Statements of Cash Flows $ 10,514 16,919 Amounts included in restricted cash represent cash received from the NFIP, which is restricted to pay flood claims under the Write Your Own program.

Investments

Investments	3 Months Ended
	Mar. 31, 2019
Investments [Abstract]
Investments	Investments (a) Our HTM fixed income securities as of March 31, 2019 represented less than 1% of our total invested assets, largely unchanged compared to December 31, 2018 . The carry value and net unrealized/unrecognized gains were $36.5 million and $ 1.5 million , respectively, at March 31, 2019 , and $37.1 million and $ 1.3 million , respectively, at December 31, 2018 . Included in the net unrealized/unrecognized gains were gross unrealized/unrecognized losses of $ 0.1 million at March 31, 2019 and $ 0.2 million at December 31, 2018 . Unrecognized holding gains and losses of HTM securities are not reflected in the Financial Statements, as they represent fair value fluctuations from the date a security is designated as HTM through the date of the balance sheet. (b) Information regarding our AFS securities as of March 31, 2019 and December 31, 2018 was as follows: March 31, 2019 ($ in thousands) Cost/ Amortized Cost Unrealized Gains Unrealized Losses Fair Value AFS fixed income securities: U.S. government and government agencies $ 125,664 1,766 (341 ) 127,089 Foreign government 20,238 299 (11 ) 20,526 Obligations of states and political subdivisions 1,110,504 39,936 (197 ) 1,150,243 Corporate securities 1,651,773 32,355 (6,113 ) 1,678,015 Collateralized loan obligations and other asset-backed securities ("CLO and other ABS") 722,573 5,050 (5,383 ) 722,240 Commercial mortgage-backed securities ("CMBS") 557,148 11,867 (815 ) 568,200 Residential mortgage-backed securities (“RMBS”) 1,275,373 27,100 (1,428 ) 1,301,045 Total AFS securities $ 5,463,273 118,373 (14,288 ) 5,567,358 December 31, 2018 ($ in thousands) Cost/ Amortized Cost Unrealized Gains Unrealized Losses Fair Value AFS fixed income securities: U.S. government and government agencies $ 120,092 1,810 (592 ) 121,310 Foreign government 23,202 36 (107 ) 23,131 Obligations of states and political subdivisions 1,121,615 19,485 (2,631 ) 1,138,469 Corporate securities 1,639,852 5,521 (27,965 ) 1,617,408 CLO and other ABS 720,193 4,112 (6,943 ) 717,362 CMBS 527,409 3,417 (3,748 ) 527,078 RMBS 1,118,435 12,988 (3,081 ) 1,128,342 Total AFS securities $ 5,270,798 47,369 (45,067 ) 5,273,100 Unrealized gains and losses of AFS securities represent fair value fluctuations from the later of: (i) the date a security is designated as AFS; or (ii) the date that an other-than-temporary impairment ("OTTI") charge is recognized on an AFS security, through the date of the balance sheet. These unrealized gains and losses are recorded in AOCI on the Consolidated Balance Sheets. (c) The severity of impairment on AFS securities in an unrealized/unrecognized loss position averaged approximately 1% of amortized cost at March 31, 2019 and approximately 2% at December 31, 2018 . Quantitative information regarding these losses is provided below. March 31, 2019 Less than 12 months 12 months or longer Total ($ in thousands) Fair Value Unrealized Losses 1 Fair Value Unrealized Losses 1 Fair Value Unrealized 1 AFS fixed income securities: U.S. government and government agencies $ 13,443 (41 ) 25,774 (300 ) 39,217 (341 ) Foreign government — — 3,509 (11 ) 3,509 (11 ) Obligations of states and political subdivisions 15,257 (71 ) 21,676 (126 ) 36,933 (197 ) Corporate securities 158,607 (2,783 ) 160,121 (3,330 ) 318,728 (6,113 ) CLO and other ABS 366,775 (4,231 ) 79,489 (1,152 ) 446,264 (5,383 ) CMBS 112,025 (505 ) 63,774 (310 ) 175,799 (815 ) RMBS 22,881 (258 ) 83,792 (1,170 ) 106,673 (1,428 ) Total AFS securities $ 688,988 (7,889 ) 438,135 (6,399 ) 1,127,123 (14,288 ) December 31, 2018 Less than 12 months 12 months or longer Total ($ in thousands) Fair Value Unrealized Losses 1 Fair Value Unrealized Losses 1 Fair Value Unrealized 1 AFS fixed income securities: U.S. government and government agencies $ 6,693 (174 ) 23,163 (418 ) 29,856 (592 ) Foreign government 12,208 (93 ) 1,482 (14 ) 13,690 (107 ) Obligations of states and political subdivisions 196,798 (2,074 ) 42,821 (557 ) 239,619 (2,631 ) Corporate securities 1,041,952 (23,649 ) 78,953 (4,316 ) 1,120,905 (27,965 ) CLO and other ABS 516,106 (6,750 ) 16,800 (193 ) 532,906 (6,943 ) CMBS 229,338 (2,548 ) 66,294 (1,200 ) 295,632 (3,748 ) RMBS 139,338 (1,660 ) 45,661 (1,421 ) 184,999 (3,081 ) Total AFS fixed income securities $ 2,142,433 (36,948 ) 275,174 (8,119 ) 2,417,607 (45,067 ) 1 Gross unrealized losses include non-OTTI unrealized amounts and OTTI losses recognized in AOCI. The decrease in the less than 12 months unrealized loss position was due to: (i) lower interest rates, with a 21-basis point decrease in 2-year U.S. Treasury Note yields and a 28-basis point decrease in 10-year U.S. Treasury Note yields during First Quarter 2019; and (ii) tightening option adjusted corporate credit spreads, with a 34-basis point decrease in the Bloomberg Barclays U.S. Aggregate Corporate Bond Index during First Quarter 2019. We do not currently intend to sell any of the securities in the tables above, nor will we be required to sell any of these securities. Considering these factors, and in accordance with our review of these securities under our OTTI policy, as described in Note 2. “Summary of Significant Accounting Policies” within Item 8. “Financial Statements and Supplementary Data.” of our 2018 Annual Report, we have concluded that they are temporarily impaired as we believe: (i) they will mature at par value; (ii) they have not incurred a credit impairment; and (iii) future values of these securities will fluctuate with changes in interest rates. This conclusion reflects our current judgment as to the financial position and future prospects of the entity that issued the investment security and underlying collateral. (d) Fixed income securities at March 31, 2019 , by contractual maturity, are shown below. Mortgage-backed securities are included in the maturity tables using the estimated average life of each security. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations, with or without call or prepayment penalties. Listed below are the contractual maturities of fixed income securities at March 31, 2019 : AFS HTM ($ in thousands) Fair Value Carrying Value Fair Value Due in one year or less $ 238,650 12,795 12,927 Due after one year through five years 2,126,600 17,574 18,728 Due after five years through 10 years 3,060,270 6,124 6,287 Due after 10 years 141,838 — — Total fixed income securities $ 5,567,358 36,493 37,942 (e) The following table summarizes our other investment portfolio by strategy: Other Investments March 31, 2019 December 31, 2018 ($ in thousands) Carrying Value Remaining Commitment Maximum Exposure to Loss 1 Carrying Value Remaining Commitment Maximum Exposure to Loss 1 Alternative Investments Private equity $ 92,371 101,297 193,668 84,352 93,688 178,040 Private credit 30,518 90,812 121,330 41,682 81,453 123,135 Real assets 28,844 25,152 53,996 27,862 27,129 54,991 Total alternative investments 151,733 217,261 368,994 153,896 202,270 356,166 Other securities 24,492 — 24,492 25,042 — 25,042 Total other investments $ 176,225 217,261 393,486 178,938 202,270 381,208 1 The maximum exposure to loss includes both the carry value of these investments and the related unfunded commitments. In addition, tax credits that have been previously recognized in Other securities are subject to the risk of recapture, which we do not consider significant. We do not have a future obligation to fund losses or debts on behalf of the investments above; however, we are contractually committed to make additional investments up to the remaining commitment outlined above. We have not provided any non-contractual financial support at any time during 2019 or 2018 . The following table sets forth gross summarized financial information for our other investments portfolio, including the portion not owned by us. The majority of these investments are carried under the equity method of accounting. The last line of the table below reflects our share of the aggregate income or loss, which is the portion included in our Financial Statements. As the majority of these investments report results to us on a one quarter lag, the summarized financial statement information for the three-month period ended December 31 is included in our First Quarter results. This information is as follows: Income Statement Information Quarter ended March 31, ($ in millions) 2019 2018 Net investment income (loss) $ (150.1 ) (56.2 ) Realized gains (losses) 143.3 1,003.0 Net change in unrealized appreciation 554.3 96.2 Net gain $ 547.5 1,043.0 Selective’s insurance subsidiaries’ alternative investments gain $ 0.6 1.6 (f) We have pledged certain AFS fixed income securities as collateral related to our relationships with the Federal Home Loan Bank of Indianapolis ("FHLBI") and the Federal Home Loan Bank of New York ("FHLBNY"). In addition, certain securities were on deposit with various state and regulatory agencies at March 31, 2019 to comply with insurance laws. We retain all rights regarding all securities pledged as collateral. The following table summarizes the market value of these securities at March 31, 2019 : ($ in millions) FHLBI Collateral FHLBNY Collateral State and Regulatory Deposits Total U.S. government and government agencies $ — — 22.5 22.5 Obligations of states and political subdivisions — — 3.9 3.9 Corporate securities — — 0.3 0.3 CMBS 7.2 20.8 — 28.0 RMBS 57.3 96.6 — 153.9 Total pledged as collateral $ 64.5 117.4 26.7 208.6 (g) We did not have exposure to any credit concentration risk of a single issuer greater than 10% of our stockholders' equity, other than certain U.S. government-backed investments, as of March 31, 2019 or December 31, 2018 . (h) The components of pre-tax net investment income earned were as follows: Quarter ended March 31, ($ in thousands) 2019 2018 Fixed income securities $ 49,033 42,041 Equity securities 1,640 1,977 Short-term investments 2,044 523 Other investments 660 1,563 Investment expenses (2,759 ) (2,873 ) Net investment income earned $ 50,618 43,231 (i) OTTI charges were $0.1 million and $1.2 million in First Quarter 2019 and First Quarter 2018 , respectively. All of these charges were related to securities for which we had the intent to sell. For a discussion of our evaluation for OTTI, refer to Note 2. "Summary of Significant Accounting Policies" in Item 8. "Financial Statements and Supplementary Data." of our 2018 Annual Report. (j) Net realized and unrealized gains and losses (excluding OTTI charges) for First Quarter 2019 and 2018 included the following: Quarter ended March 31, ($ in thousands) 2019 2018 Net realized gains (losses) on the disposals of securities: Fixed income securities $ 1,143 (3,335 ) Equity securities 2,280 8,069 Short-term investments 14 (3 ) Other investments 7 — Net realized gains on the disposal of securities 3,444 4,731 OTTI charges (104 ) (1,212 ) Net realized gains 3,340 3,519 Unrealized gains (losses) recognized in income on equity securities 1 10,111 (14,068 ) Total net realized and unrealized investment gains (losses) $ 13,451 (10,549 ) 1 Includes unrealized holding gains (losses) of: (i) $12.0 million in First Quarter 2019 and $(5.1) million in First Quarter 2018 on equity securities remaining in our portfolio as of March 31, 2019 and 2018, respectively; and (ii) $(1.9) million in First Quarter 2019 and $(9.0) million in First Quarter 2018 on equity securities sold in each respective period. The components of net realized gains on disposals of securities for the periods indicated were as follows: Quarter ended March 31, ($ in thousands) 2019 2018 HTM fixed income securities Gains $ — 2 Losses — — AFS fixed income securities Gains 1,844 2,623 Losses (701 ) (5,960 ) Equity securities Gains 2,280 8,399 Losses — (330 ) Short-term investments Gains 14 1 Losses — (4 ) Other investments Gains 7 — Losses — — Total net realized gains on disposals of securities $ 3,444 4,731 Realized gains and losses on the sale of investments are determined on the basis of the cost of the specific investments sold. Proceeds from the sales of AFS fixed income securities were $218.4 million and $675.4 million in First Quarter 2019 and First Quarter 2018 , respectively. Proceeds from the sales of equity securities were $3.7 million and $40.7 million in First Quarter 2019 and First Quarter 2018 , respectively.

Indebtedness

Indebtedness	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Debt Disclosure	Indebtedness The table below provides a summary of our outstanding debt at March 31, 2019 and December 31, 2018: Outstanding Debt Issuance Date Maturity Date Interest Rate Original Amount 2019 Carry Value ($ in thousands) Debt Discount and Unamortized Issuance Cost March 31, 2019 December 31, 2018 Description Long term Issuance: Senior Notes 3/1/2019 3/1/2049 5.375 % $ 300,000 9,293 290,707 — Redemption: Senior Notes 2/8/2013 2/9/2043 5.875 % 185,000 — — 180,771 Other Outstanding: FHLBI 12/16/2016 12/16/2026 3.03 % 60,000 — 60,000 60,000 FHLBNY 8/15/2016 8/16/2021 1.56 % 25,000 — 25,000 25,000 FHLBNY 7/21/2016 7/21/2021 1.61 % 25,000 — 25,000 25,000 Senior Notes 11/3/2005 11/1/2035 6.70 % 100,000 917 99,083 99,069 Senior Notes 11/16/2004 11/15/2034 7.25 % 50,000 293 49,707 49,700 Finance Lease Obligations 1 607 — Total long-term debt $ 745,000 10,503 550,104 439,540 1 Concurrent with the adoption of ASU 2016-02 discussed in Note 2. "Adoption of Accounting Pronouncements," finance lease obligations are now captured in Long-term debt on our Consolidated Balance Sheets. Short Term Debt Activity On March 7, 2019, Selective Insurance Company of America (“SICA”) borrowed short-term funds of $50 million from the FHLBNY at an interest rate of 2.64% . This borrowing was repaid on March 28, 2019. Long Term Debt Activity In First Quarter 2019, we issued $300 million of 5.375% Senior Notes due 2049 at a discount of $5.9 million which, when coupled with debt issuance costs of approximately $3.4 million , resulted in net proceeds from the offering of $290.7 million . The Senior Notes will pay interest on March 1 and September 1 of each year, beginning on September 1, 2019. A portion of the proceeds from this debt issuance was used to fully redeem the $185 million aggregate principal amount of our 5.875% Senior Notes due 2043 , with the remaining $106 million being used for general corporate purposes. The 5.875% Senior Notes had pre-tax debt retirement costs of $4.2 million , or $3.3 million after tax, which was recorded in Interest expense on the Consolidated Statements of Income in First Quarter 2019. For detailed information on our indebtedness, see Note 10. "Indebtedness" in Item 8. "Financial Statements and Supplementary Data." of our 2018 Annual Report.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The financial assets in our investment portfolio are primarily measured at fair value as disclosed on the Consolidated Balance Sheets. The following table presents the carrying amounts and estimated fair values of our financial liabilities as of March 31, 2019 and December 31, 2018: March 31, 2019 December 31, 2018 ($ in thousands) Carrying Amount Fair Value Carrying Amount Fair Value Financial Liabilities Long-term debt: 7.25% Senior Notes 49,907 61,391 49,907 57,032 6.70% Senior Notes 99,467 115,671 99,462 107,075 5.875% Senior Notes — — 185,000 177,230 5.375% Senior Notes 294,097 307,215 — — 1.61% borrowings from FHLBNY 25,000 24,474 25,000 24,218 1.56% borrowings from FHLBNY 25,000 24,426 25,000 24,162 3.03% borrowings from FHLBI 60,000 61,814 60,000 58,905 Subtotal long-term debt 553,471 594,991 444,369 448,622 Unamortized debt issuance costs (3,974 ) (4,829 ) Finance lease obligations 607 — Total long-term debt 550,104 439,540 For a discussion of our long-term debt activity in First Quarter 2019, see Note 5. "Indebtedness" and for a discussion of the fair value hierarchy and techniques used to value our financial assets and liabilities, refer to Note 2. "Summary of Significant Accounting Policies" in Item 8. "Financial Statements and Supplementary Data." of our 2018 Annual Report. The following tables provide quantitative disclosures of our financial assets that were measured and recorded at fair value at March 31, 2019 and December 31, 2018 : March 31, 2019 Fair Value Measurements Using ($ in thousands) Assets Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1) 1 Significant Other Observable Inputs (Level 2) 1 Significant Unobservable Inputs (Level 3) Description Measured on a recurring basis: AFS fixed income securities: U.S. government and government agencies $ 127,089 68,645 58,444 — Foreign government 20,526 — 20,526 — Obligations of states and political subdivisions 1,150,243 — 1,150,243 — Corporate securities 1,678,015 — 1,661,596 16,419 CLO and other ABS 722,240 — 690,948 31,292 CMBS 568,200 — 568,200 — RMBS 1,301,045 — 1,301,045 — Total AFS fixed income securities 5,567,358 68,645 5,451,002 47,711 Equity securities: Common stock 2 160,011 119,977 — — Preferred stock 3,005 3,005 — — Total equity securities 163,016 122,982 — — Short-term investments 290,653 289,232 1,421 — Total assets measured at fair value $ 6,021,027 480,859 5,452,423 47,711 December 31, 2018 Fair Value Measurements Using ($ in thousands) Assets Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) 1 Significant Other Observable Inputs (Level 2) 1 Significant Unobservable Inputs (Level 3) Description Measured on a recurring basis: AFS fixed income securities: U.S. government and government agencies $ 121,310 78,381 42,929 — Foreign government 23,131 — 23,131 — Obligations of states and political subdivisions 1,138,469 — 1,138,469 — Corporate securities 1,617,408 — 1,617,408 — CLO and other ABS 717,362 — 709,953 7,409 CMBS 527,078 — 527,078 — RMBS 1,128,342 — 1,128,342 — Total AFS fixed income securities 5,273,100 78,381 5,187,310 7,409 Equity securities: Common stock 2 144,727 107,397 — — Preferred stock 2,912 2,912 — — Total equity securities 147,639 110,309 — — Short-term investments 323,864 321,370 2,494 — Total assets measured at fair value $ 5,744,603 510,060 5,189,804 7,409 1 There were no transfers of securities between Level 1 and Level 2. 2 Investments amounting to $40.0 million at March 31, 2019 , and $23.7 million at December 31, 2018 , were measured at fair value using net asset value per share (or its practical expedient) and have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to total assets measured at fair value. The following table provides a summary of Level 3 changes in First Quarter 2019 : March 31, 2019 ($ in thousands) Corporate Securities CLO and Other ABS Total Fair value, December 31, 2018 — 7,409 7,409 Total net (losses) gains for the period included in: OCI — (225 ) (225 ) Net income — — — Purchases — 12,434 12,434 Sales — — — Issuances — — — Settlements — — — Transfers into Level 3 16,419 11,674 28,093 Transfers out of Level 3 — — — Fair value, March 31, 2019 16,419 31,292 47,711 There were no material changes in the fair value of securities measured using Level 3 prices in First Quarter 2018 . The following tables provide quantitative information regarding our financial assets and liabilities that were disclosed at fair value at March 31, 2019 and December 31, 2018 : March 31, 2019 Fair Value Measurements Using ($ in thousands) Assets/ Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets HTM: Obligations of states and political subdivisions $ 17,923 — 17,923 — Corporate securities 20,019 — 20,019 — Total HTM fixed income securities $ 37,942 — 37,942 — Financial Liabilities Long-term debt: 7.25% Senior Notes $ 61,391 — 61,391 — 6.70% Senior Notes 115,671 — 115,671 — 5.375% Senior Notes 307,215 — 307,215 — 1.61% borrowings from FHLBNY 24,474 — 24,474 — 1.56% borrowings from FHLBNY 24,426 — 24,426 — 3.03% borrowings from FHLBI 61,814 — 61,814 — Total long-term debt $ 594,991 — 594,991 — December 31, 2018 Fair Value Measurements Using ($ in thousands) Assets/ Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets HTM: Obligations of states and political subdivisions $ 17,969 — 17,969 — Corporate securities 20,348 — 20,348 — Total HTM fixed income securities $ 38,317 — 38,317 — Financial Liabilities Long-term debt: 7.25% Senior Notes $ 57,032 — 57,032 — 6.70% Senior Notes 107,075 — 107,075 — 5.875% Senior Notes 177,230 177,230 — — 1.61% borrowings from FHLBNY 24,218 — 24,218 — 1.56% borrowings from FHLBNY 24,162 — 24,162 — 3.03% borrowings from FHLBI 58,905 — 58,905 — Total long-term debt $ 448,622 177,230 271,392 —

Reinsurance

Reinsurance	3 Months Ended
	Mar. 31, 2019
Reinsurance Disclosures [Abstract]
Reinsurance	Reinsurance The following table contains a listing of direct, assumed, and ceded reinsurance amounts for premiums written, premiums earned, and loss and loss expenses incurred for the periods indicated. For more information concerning reinsurance, refer to Note 8. “Reinsurance” in Item 8. “Financial Statements and Supplementary Data.” of our 2018 Annual Report. Quarter ended March 31, ($ in thousands) 2019 2018 Premiums written: Direct $ 766,394 714,234 Assumed 6,555 6,271 Ceded (100,002 ) (95,945 ) Net $ 672,947 624,560 Premiums earned: Direct $ 728,037 683,733 Assumed 6,562 6,124 Ceded (102,026 ) (98,029 ) Net $ 632,573 591,828 Loss and loss expenses incurred: Direct $ 424,657 420,916 Assumed 5,265 8,004 Ceded (43,343 ) (43,979 ) Net $ 386,579 384,941 Ceded premiums and losses related to our participation in the National Flood Insurance Program ("NFIP"), under which 100% of our flood premiums, losses, and loss expenses are ceded to the NFIP, are as follows: Ceded to NFIP Quarter ended March 31, ($ in thousands) 2019 2018 Ceded premiums written $ (60,013 ) (56,669 ) Ceded premiums earned (62,263 ) (58,991 ) Ceded loss and loss expenses incurred (13,686 ) (15,719 )

Reserve for Loss and Loss Expen

Reserve for Loss and Loss Expense	3 Months Ended
	Mar. 31, 2019
Insurance Loss Reserves [Abstract]
Reserve for Loss and Loss Expense	Reserve for Loss and Loss Expense The table below provides a roll forward of reserve for loss and loss expense balances: Quarter ended March 31, ($ in thousands) 2019 2018 Gross reserve for loss and loss expense, at beginning of year $ 3,893,868 3,771,240 Less: reinsurance recoverable on unpaid loss and loss expense, at beginning of year 537,388 585,855 Net reserve for loss and loss expense, at beginning of year 3,356,480 3,185,385 Incurred loss and loss expense for claims occurring in the: Current year 397,253 388,801 Prior years (10,674 ) (3,860 ) Total incurred loss and loss expense 386,579 384,941 Paid loss and loss expense for claims occurring in the: Current year 73,964 79,345 Prior years 246,168 248,738 Total paid loss and loss expense 320,132 328,083 Net reserve for loss and loss expense, at end of period 3,422,927 3,242,243 Add: Reinsurance recoverable on unpaid loss and loss expense, at end of period 543,582 549,837 Gross reserve for loss and loss expense at end of period $ 3,966,509 3,792,080 Prior year development in First Quarter 2019 of $10.7 million was primarily driven by favorable casualty development of $8.0 million in our workers compensation line of business and $2.0 million in our general liability line of business. Prior year development in First Quarter 2018 of $3.9 million included $8.0 million of favorable casualty development and $4.1 million of unfavorable property development. The favorable casualty reserve development included $16.0 million in our workers compensation line of business, partially offset by unfavorable development of $8.0 million in our commercial automobile line of business.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Segment Information	Segment Information The results of our four reportable segments are evaluated as follows: • Our Standard Commercial Lines, Standard Personal Lines, and Excess and Surplus ("E&S") Lines are evaluated based on before and after-tax underwriting results (net premiums earned, incurred loss and loss expense, policyholder dividends, policy acquisition costs, and other underwriting expenses), return on equity ("ROE") contribution, and combined ratios. • Our Investments segment is primarily evaluated based on after-tax net investment income and its ROE contribution. Also included in Investment segment results are after-tax net realized and unrealized gains and losses, which are not included in non-GAAP operating income. In computing the results of each segment, we do not make adjustments for interest expense or corporate expenses. We do not maintain separate investment portfolios for the segments and therefore, do not allocate assets to the segments. The following summaries present revenues (net investment income and net realized and unrealized gains on investments in the case of the Investments segment) and pre-tax income for the individual segments: Revenue by Segment Quarter ended March 31, ($ in thousands) 2019 2018 Standard Commercial Lines: Net premiums earned: Commercial automobile $ 131,186 118,231 Workers compensation 78,715 78,823 General liability 161,525 149,829 Commercial property 86,067 80,326 Businessowners’ policies 26,081 25,591 Bonds 8,904 8,134 Other 4,706 4,430 Miscellaneous income 2,044 1,826 Total Standard Commercial Lines revenue 499,228 467,190 Standard Personal Lines: Net premiums earned: Personal automobile 43,163 40,442 Homeowners 32,130 32,201 Other 2,014 1,613 Miscellaneous income 276 352 Total Standard Personal Lines revenue 77,583 74,608 E&S Lines: Net premiums earned: Casualty lines 44,528 38,540 Property lines 13,554 13,668 Miscellaneous income — 1 Total E&S Lines revenue 58,082 52,209 Investments: Net investment income 50,618 43,231 Net realized and unrealized investment gains (losses) 13,451 (10,549 ) Total Investments revenue 64,069 32,682 Total revenues $ 698,962 626,689 Income Before and After Federal Income Tax Quarter ended March 31, ($ in thousands) 2019 2018 Standard Commercial Lines: Underwriting gain, before federal income tax $ 25,815 6,804 Underwriting gain, after federal income tax 20,394 5,375 Combined ratio 94.8 % 98.5 ROE contribution 4.4 1.3 Standard Personal Lines: Underwriting gain (loss), before federal income tax $ 3,167 (1,506 ) Underwriting gain (loss), after federal income tax 2,502 (1,190 ) Combined ratio 95.9 % 102.0 ROE contribution 0.5 (0.3 ) E&S Lines: Underwriting gain (loss), before federal income tax $ 4,579 (565 ) Underwriting gain (loss), after federal income tax 3,617 (446 ) Combined ratio 92.1 % 101.1 ROE contribution 0.8 (0.1 ) Investments: Net investment income $ 50,618 43,231 Net realized and unrealized investment gains (losses) 13,451 (10,549 ) Total investment segment income, before federal income tax 64,069 32,682 Tax on investment segment income 12,120 5,226 Total investment segment income, after federal income tax $ 51,949 27,456 ROE contribution of after-tax net investment income 8.9 8.5 Reconciliation of Segment Results to Income Before Federal Income Tax Quarter ended March 31, ($ in thousands) 2019 2018 Underwriting gain (loss) Standard Commercial Lines $ 25,815 6,804 Standard Personal Lines 3,167 (1,506 ) E&S Lines 4,579 (565 ) Investment income 64,069 32,682 Total all segments 97,630 37,415 Interest expense (11,526 ) (6,152 ) Corporate expenses (12,410 ) (11,332 ) Income, before federal income tax $ 73,694 19,931

Retirement Plans

Retirement Plans	3 Months Ended
	Mar. 31, 2019
Retirement Benefits [Abstract]
Retirement Plans	Retirement Plans SICA's primary pension plan is the Retirement Income Plan for Selective Insurance Company of America (the “Pension Plan”). SICA also sponsors the Supplemental Excess Retirement Plan (the “Excess Plan”) and a life insurance benefit plan. All plans are closed to new entrants and benefits ceased accruing under the Pension Plan and the Excess Plan after March 31, 2016 . For more information concerning SICA's retirement plans, refer to Note 14. “Retirement Plans” in Item 8. “Financial Statements and Supplementary Data.” of our 2018 Annual Report. The following tables provide information regarding the Pension Plan: Pension Plan Quarter ended March 31, ($ in thousands) 2019 2018 Net Periodic Benefit Cost: Interest cost $ 3,377 3,095 Expected return on plan assets (5,279 ) (5,682 ) Amortization of unrecognized net actuarial loss 644 494 Total net periodic benefit cost 1 $ (1,258 ) (2,093 ) 1 The components of net periodic benefit cost are included within "Loss and loss expense incurred" and "Other insurance expenses" on the Consolidated Statements of Income. Pension Plan Quarter ended March 31, 2019 2018 Weighted-Average Expense Assumptions: Discount rate 4.46 % 3.78 % Effective interest rate for calculation of interest cost 4.12 3.46 Expected return on plan assets 6.50 6.36

Comprehensive Income

Comprehensive Income	3 Months Ended
	Mar. 31, 2019
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Comprehensive Income	Comprehensive Income The components of comprehensive income, both gross and net of tax, for First Quarter 2019 and 2018 were as follows: First Quarter 2019 ($ in thousands) Gross Tax Net Net income $ 73,694 12,346 61,348 Components of OCI: Unrealized gains on investment securities : Unrealized holding gains during the period 102,926 21,613 81,313 Amounts reclassified into net income: HTM securities (9 ) (2 ) (7 ) Realized gains on disposals and OTTI of AFS securities (1,077 ) (226 ) (851 ) Total unrealized gains on investment securities 101,840 21,385 80,455 Defined benefit pension and post-retirement plans: Amounts reclassified into net income: Net actuarial loss 664 139 525 Total defined benefit pension and post-retirement plans 664 139 525 Other comprehensive income 102,504 21,524 80,980 Comprehensive income $ 176,198 33,870 142,328 First Quarter 2018 ($ in thousands) Gross Tax Net Net income $ 19,931 1,006 18,925 Components of other comprehensive loss: Unrealized losses on investment securities : Unrealized holding losses during the period (85,315 ) (17,917 ) (67,398 ) Amounts reclassified into net income: HTM securities (12 ) (2 ) (10 ) Realized losses on disposals and OTTI of AFS securities 4,549 955 3,594 Total unrealized losses on investment securities (80,778 ) (16,964 ) (63,814 ) Defined benefit pension and post-retirement plans: Amounts reclassified into net income: Net actuarial loss 532 112 420 Total defined benefit pension and post-retirement plans 532 112 420 Other comprehensive loss (80,246 ) (16,852 ) (63,394 ) Comprehensive loss $ (60,315 ) (15,846 ) (44,469 ) The balances of, and changes in, each component of AOCI (net of taxes) as of March 31, 2019 were as follows: March 31, 2019 Defined Benefit Pension and Post-Retirement Plans Net Unrealized Gains (Losses) on Investment Securities Total AOCI ($ in thousands) OTTI Related HTM Related All Other Investments Subtotal Balance, December 31, 2018 $ (71 ) 71 1,888 1,888 (79,844 ) (77,956 ) OCI before reclassifications — — 81,313 81,313 — 81,313 Amounts reclassified from AOCI — (7 ) (851 ) (858 ) 525 (333 ) Net current period OCI — (7 ) 80,462 80,455 525 80,980 Balance, March 31, 2019 $ (71 ) 64 82,350 82,343 (79,319 ) 3,024 The reclassifications out of AOCI were as follows: Quarter ended March 31, Affected Line Item in the Unaudited Consolidated Statements of Income ($ in thousands) 2019 2018 HTM related Unrealized losses on HTM disposals $ — 1 Net realized and unrealized gains (losses) Amortization of net unrealized gains on HTM securities (9 ) (13 ) Net investment income earned (9 ) (12 ) Income before federal income tax 2 2 Total federal income tax expense (7 ) (10 ) Net income Realized (gains) losses on AFS and OTTI Realized (gains) losses on AFS disposals and OTTI (1,077 ) 4,549 Net realized and unrealized gains (losses) (1,077 ) 4,549 Income before federal income tax 226 (955 ) Total federal income tax expense (851 ) 3,594 Net income Defined benefit pension and post-retirement life plans Net actuarial loss 145 112 Loss and loss expense incurred 519 420 Other insurance expenses Total defined benefit pension and post-retirement life 664 532 Income before federal income tax (139 ) (112 ) Total federal income tax expense 525 420 Net income Total reclassifications for the period $ (333 ) 4,004 Net income

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	Leases We have various operating leases for office space, equipment, and fleet vehicles. In addition, we have various finance leases for computer hardware. Such lease agreements, which expire at various dates through 2030, are generally renewed or replaced by similar leases. We determine if an arrangement is a lease on the commencement date of the contract. Lease assets represent our right to use an underlying asset for the lease term, and lease liabilities represent our obligation to make lease payments arising from the lease. The lease asset and liability are measured by the present value of the future minimum lease payments over the lease term. Our fleet vehicle leases include a residual value guarantee; however, it is not probable of being owed. Therefore, there is no impact to the lease liability or lease asset. To measure the present value, the discount rate available in the contract is used. If the discount rate is not readily determinable, our incremental borrowing rate is used. The lease asset is then adjusted to exclude lease incentives. We recognize variable lease payments in the period in which the obligation for those payments is incurred. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. Lease expense is calculated using the straight-line method. Upon adoption of ASU 2016-02 on January 1, 2019, we recorded operating lease right-of-use assets of $20.7 million with related lease liabilities of $21.0 million . The differential of $0.3 million was recognized, on an after-tax basis, as a cumulative-effect adjustment to the opening balance of retained earnings as of January 1, 2019. Financing lease right-of-use assets and the related lease liabilities were $0.9 million as of January 1, 2019. See Note 2. "Adoption of Accounting Pronouncements" in this Form 10-Q for additional information regarding ASU 2016-02 and accounting policy elections made. The components of lease expense in First Quarter 2019 were as follows: ($ in thousands) Quarter ended March 31, 2019 Operating lease cost, included in Other insurance expenses on the Consolidated Statements of Income $ 2,152 Finance lease cost: Amortization of assets, included in Other insurance expenses on the Consolidated Statements of Income 284 Interest on lease liabilities, included in Interest expense on the Consolidated Statements of Income — Total finance lease cost 284 Variable lease cost, included in Other insurance expenses on the Consolidated Statements of Income 788 Short-term lease cost, included in Other insurance expenses on the Consolidated Statements of Income 739 The following table provides supplemental information regarding our operating and finance leases. March 31, 2019 Weighted-average remaining lease term Operating leases 5 years Finance leases 1 Weighted-average discount rate Operating leases 3.3 % Finance leases 1 — 1 Prior to adoption of ASU 2016-02, our historical capital lease liability and asset were measured using an un-discounted cash flow stream due to immateriality of the capital lease population. As we have elected the practical expedient that does not require us to reassess our population of capital leases upon adoption of ASU 2016-02, our existing finance leases do not have a weighted-average discount rate. Operating and finance lease asset and liability balances are included within the following line items on the Consolidated Balance Sheets: ($ in thousands) March 31, 2019 Operating leases Other assets $ 24,946 Other liabilities 25,415 Finance leases Property and equipment - at cost, net of accumulated depreciation and amortization 607 Long-term debt 607 At March 31, 2019, the maturities of our lease liabilities were as follows: ($ in thousands) Finance Leases Operating Leases Total Year ended December 31, 2019 (excluding the three months ended March 31, 2019) $ 444 5,779 6,223 2020 141 7,355 7,496 2021 22 5,083 5,105 2022 — 3,641 3,641 2023 — 2,900 2,900 Thereafter — 9,698 9,698 Total lease payments 607 34,456 35,063 Less: imputed interest — 3,610 3,610 Less: leases that have not yet commenced — 5,431 5,431 Total lease liabilities $ 607 25,415 26,022 At December 31, 2018, the maturities of our lease liabilities for capital and operating leases were as follows: ($ in thousands) Capital Leases Operating Leases Total 2019 $ 728 7,762 8,490 2020 141 7,355 7,496 2021 22 5,083 5,105 2022 — 3,641 3,641 2023 — 2,900 2,900 Thereafter — 9,698 9,698 Total minimum payment required $ 891 36,439 37,330 Refer to Note. 3 "Statements of Cash Flows" in this Form 10-Q for supplemental cash and non-cash transactions included in the measurement of operating and finance lease liabilities.

Litigation

Litigation	3 Months Ended
	Mar. 31, 2019
Loss Contingency, Information about Litigation Matters [Abstract]
Litigation	Litigation In the ordinary course of conducting business, we are named as defendants in various legal proceedings. Most of these proceedings are claims litigation involving our ten insurance subsidiaries ("Insurance Subsidiaries") as either: (i) liability insurers defending or providing indemnity for third-party claims brought against our customers; or (ii) insurers defending first-party coverage claims brought against them. We account for such activity through the establishment of unpaid loss and loss expense reserves. We expect that any potential ultimate liability in such ordinary course claims litigation will not be material to our consolidated financial condition, results of operations, or cash flows after consideration of provisions made for potential losses and costs of defense. From time to time, our Insurance Subsidiaries also are named as defendants in other legal actions, some of which assert claims for substantial amounts. These actions include, among others, putative class actions seeking certification of a state or national class. Such putative class actions have alleged, for example, improper reimbursement of medical providers paid under workers compensation and personal and commercial automobile insurance policies. Similarly, our Insurance Subsidiaries are also named from time-to-time in individual actions seeking extra-contractual damages, punitive damages, or penalties, some of which allege bad faith in the handling of insurance claims. We believe that we have valid defenses to these cases. We expect that any potential ultimate liability in any such lawsuit will not be material to our consolidated financial condition, after consideration of provisions made for estimated losses. Nonetheless, given the inherent unpredictability of litigation and the large or indeterminate amounts sought in certain of these actions, an adverse outcome in certain matters could possibly have a material adverse effect on our consolidated results of operations or cash flows in particular quarterly or annual periods. As of March 31, 2019 , we do not believe the Company was involved in any legal action that could have a material adverse effect on our consolidated financial condition, results of operations, or cash flows.

Statements of Cash Flow (Tables

Statements of Cash Flow (Tables)	3 Months Ended
	Mar. 31, 2019
Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	Quarter ended March 31, ($ in thousands) 2019 2018 Cash paid during the period for: Interest $ 4,477 3,455 Federal income tax — (2,807 ) Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases 1 1,983 — Financing cash flows from finance leases 284 734 Non-cash items: Corporate actions related to fixed income securities, AFS 2 18,447 11,347 Assets acquired under operating lease arrangements 1 6,136 — Non-cash purchase of property and equipment 162 —
Schedule of Cash and Restricted Cash	($ in thousands) March 31, 2019 December 31, 2018 Cash $ 516 505 Restricted cash 9,998 16,414 Total cash and restricted cash shown in the Statements of Cash Flows $ 10,514 16,919

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2019
Investments [Line Items]
Schedule of Available-for-sale Securities	March 31, 2019 ($ in thousands) Cost/ Amortized Cost Unrealized Gains Unrealized Losses Fair Value AFS fixed income securities: U.S. government and government agencies $ 125,664 1,766 (341 ) 127,089 Foreign government 20,238 299 (11 ) 20,526 Obligations of states and political subdivisions 1,110,504 39,936 (197 ) 1,150,243 Corporate securities 1,651,773 32,355 (6,113 ) 1,678,015 Collateralized loan obligations and other asset-backed securities ("CLO and other ABS") 722,573 5,050 (5,383 ) 722,240 Commercial mortgage-backed securities ("CMBS") 557,148 11,867 (815 ) 568,200 Residential mortgage-backed securities (“RMBS”) 1,275,373 27,100 (1,428 ) 1,301,045 Total AFS securities $ 5,463,273 118,373 (14,288 ) 5,567,358 December 31, 2018 ($ in thousands) Cost/ Amortized Cost Unrealized Gains Unrealized Losses Fair Value AFS fixed income securities: U.S. government and government agencies $ 120,092 1,810 (592 ) 121,310 Foreign government 23,202 36 (107 ) 23,131 Obligations of states and political subdivisions 1,121,615 19,485 (2,631 ) 1,138,469 Corporate securities 1,639,852 5,521 (27,965 ) 1,617,408 CLO and other ABS 720,193 4,112 (6,943 ) 717,362 CMBS 527,409 3,417 (3,748 ) 527,078 RMBS 1,118,435 12,988 (3,081 ) 1,128,342 Total AFS securities $ 5,270,798 47,369 (45,067 ) 5,273,100
Schedule of Fair Value and Gross Pre-Tax Net Unrealized Loss of Securities by Length of Time, AFS	March 31, 2019 Less than 12 months 12 months or longer Total ($ in thousands) Fair Value Unrealized Losses 1 Fair Value Unrealized Losses 1 Fair Value Unrealized 1 AFS fixed income securities: U.S. government and government agencies $ 13,443 (41 ) 25,774 (300 ) 39,217 (341 ) Foreign government — — 3,509 (11 ) 3,509 (11 ) Obligations of states and political subdivisions 15,257 (71 ) 21,676 (126 ) 36,933 (197 ) Corporate securities 158,607 (2,783 ) 160,121 (3,330 ) 318,728 (6,113 ) CLO and other ABS 366,775 (4,231 ) 79,489 (1,152 ) 446,264 (5,383 ) CMBS 112,025 (505 ) 63,774 (310 ) 175,799 (815 ) RMBS 22,881 (258 ) 83,792 (1,170 ) 106,673 (1,428 ) Total AFS securities $ 688,988 (7,889 ) 438,135 (6,399 ) 1,127,123 (14,288 ) December 31, 2018 Less than 12 months 12 months or longer Total ($ in thousands) Fair Value Unrealized Losses 1 Fair Value Unrealized Losses 1 Fair Value Unrealized 1 AFS fixed income securities: U.S. government and government agencies $ 6,693 (174 ) 23,163 (418 ) 29,856 (592 ) Foreign government 12,208 (93 ) 1,482 (14 ) 13,690 (107 ) Obligations of states and political subdivisions 196,798 (2,074 ) 42,821 (557 ) 239,619 (2,631 ) Corporate securities 1,041,952 (23,649 ) 78,953 (4,316 ) 1,120,905 (27,965 ) CLO and other ABS 516,106 (6,750 ) 16,800 (193 ) 532,906 (6,943 ) CMBS 229,338 (2,548 ) 66,294 (1,200 ) 295,632 (3,748 ) RMBS 139,338 (1,660 ) 45,661 (1,421 ) 184,999 (3,081 ) Total AFS fixed income securities $ 2,142,433 (36,948 ) 275,174 (8,119 ) 2,417,607 (45,067 ) 1 Gross unrealized losses include non-OTTI unrealized amounts and OTTI losses recognized in AOCI.
Schedule of Fixed Maturity Securities By Contractual Maturities	AFS HTM ($ in thousands) Fair Value Carrying Value Fair Value Due in one year or less $ 238,650 12,795 12,927 Due after one year through five years 2,126,600 17,574 18,728 Due after five years through 10 years 3,060,270 6,124 6,287 Due after 10 years 141,838 — — Total fixed income securities $ 5,567,358 36,493 37,942
Schedule of Other Investment Portfolio By Strategy And Remaining Commitment Amount and Maximum Exposure to Loss Associated With Each Strategy	Other Investments March 31, 2019 December 31, 2018 ($ in thousands) Carrying Value Remaining Commitment Maximum Exposure to Loss 1 Carrying Value Remaining Commitment Maximum Exposure to Loss 1 Alternative Investments Private equity $ 92,371 101,297 193,668 84,352 93,688 178,040 Private credit 30,518 90,812 121,330 41,682 81,453 123,135 Real assets 28,844 25,152 53,996 27,862 27,129 54,991 Total alternative investments 151,733 217,261 368,994 153,896 202,270 356,166 Other securities 24,492 — 24,492 25,042 — 25,042 Total other investments $ 176,225 217,261 393,486 178,938 202,270 381,208 1 The maximum exposure to loss includes both the carry value of these investments and the related unfunded commitments. In addition, tax credits that have been previously recognized in Other securities are subject to the risk of recapture, which we do not consider significant.
Schedule of Aggregated Summarized Income Statement Financial Information For Partnerships In Our Alternative Investment Portfolio	Income Statement Information Quarter ended March 31, ($ in millions) 2019 2018 Net investment income (loss) $ (150.1 ) (56.2 ) Realized gains (losses) 143.3 1,003.0 Net change in unrealized appreciation 554.3 96.2 Net gain $ 547.5 1,043.0 Selective’s insurance subsidiaries’ alternative investments gain $ 0.6 1.6
Schedule of Securities Pledged As Collateral	($ in millions) FHLBI Collateral FHLBNY Collateral State and Regulatory Deposits Total U.S. government and government agencies $ — — 22.5 22.5 Obligations of states and political subdivisions — — 3.9 3.9 Corporate securities — — 0.3 0.3 CMBS 7.2 20.8 — 28.0 RMBS 57.3 96.6 — 153.9 Total pledged as collateral $ 64.5 117.4 26.7 208.6
Schedule of Pre-Tax Net Investment Income Earned	Quarter ended March 31, ($ in thousands) 2019 2018 Fixed income securities $ 49,033 42,041 Equity securities 1,640 1,977 Short-term investments 2,044 523 Other investments 660 1,563 Investment expenses (2,759 ) (2,873 ) Net investment income earned $ 50,618 43,231
Schedule of Components of Net Realized and Unrealized Gains and Losses Excluding OTTI Charges	Quarter ended March 31, ($ in thousands) 2019 2018 Net realized gains (losses) on the disposals of securities: Fixed income securities $ 1,143 (3,335 ) Equity securities 2,280 8,069 Short-term investments 14 (3 ) Other investments 7 — Net realized gains on the disposal of securities 3,444 4,731 OTTI charges (104 ) (1,212 ) Net realized gains 3,340 3,519 Unrealized gains (losses) recognized in income on equity securities 1 10,111 (14,068 ) Total net realized and unrealized investment gains (losses) $ 13,451 (10,549 ) 1 Includes unrealized holding gains (losses) of: (i) $12.0 million in First Quarter 2019 and $(5.1) million in First Quarter 2018 on equity securities remaining in our portfolio as of March 31, 2019 and 2018, respectively; and (ii) $(1.9) million in First Quarter 2019 and $(9.0) million in First Quarter 2018 on equity securities sold in each respective period.
Schedule of Realized Gains and Losses on Disposals of Securities	Quarter ended March 31, ($ in thousands) 2019 2018 HTM fixed income securities Gains $ — 2 Losses — — AFS fixed income securities Gains 1,844 2,623 Losses (701 ) (5,960 ) Equity securities Gains 2,280 8,399 Losses — (330 ) Short-term investments Gains 14 1 Losses — (4 ) Other investments Gains 7 — Losses — — Total net realized gains on disposals of securities $ 3,444 4,731

Indebtedness (Tables)

Indebtedness (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Outstanding Debt	Outstanding Debt Issuance Date Maturity Date Interest Rate Original Amount 2019 Carry Value ($ in thousands) Debt Discount and Unamortized Issuance Cost March 31, 2019 December 31, 2018 Description Long term Issuance: Senior Notes 3/1/2019 3/1/2049 5.375 % $ 300,000 9,293 290,707 — Redemption: Senior Notes 2/8/2013 2/9/2043 5.875 % 185,000 — — 180,771 Other Outstanding: FHLBI 12/16/2016 12/16/2026 3.03 % 60,000 — 60,000 60,000 FHLBNY 8/15/2016 8/16/2021 1.56 % 25,000 — 25,000 25,000 FHLBNY 7/21/2016 7/21/2021 1.61 % 25,000 — 25,000 25,000 Senior Notes 11/3/2005 11/1/2035 6.70 % 100,000 917 99,083 99,069 Senior Notes 11/16/2004 11/15/2034 7.25 % 50,000 293 49,707 49,700 Finance Lease Obligations 1 607 — Total long-term debt $ 745,000 10,503 550,104 439,540 1 Concurrent with the adoption of ASU 2016-02 discussed in Note 2. "Adoption of Accounting Pronouncements," finance lease obligations are now captured in Long-term debt on our Consolidated Balance Sheets.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Schedule of Carrying Values and Estimated Fair Values of Financial Liabilities	March 31, 2019 December 31, 2018 ($ in thousands) Carrying Amount Fair Value Carrying Amount Fair Value Financial Liabilities Long-term debt: 7.25% Senior Notes 49,907 61,391 49,907 57,032 6.70% Senior Notes 99,467 115,671 99,462 107,075 5.875% Senior Notes — — 185,000 177,230 5.375% Senior Notes 294,097 307,215 — — 1.61% borrowings from FHLBNY 25,000 24,474 25,000 24,218 1.56% borrowings from FHLBNY 25,000 24,426 25,000 24,162 3.03% borrowings from FHLBI 60,000 61,814 60,000 58,905 Subtotal long-term debt 553,471 594,991 444,369 448,622 Unamortized debt issuance costs (3,974 ) (4,829 ) Finance lease obligations 607 — Total long-term debt 550,104 439,540
Schedule of Quantitative Disclosures of Our Financial Assets That Were Measured At Fair Value	March 31, 2019 Fair Value Measurements Using ($ in thousands) Assets Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1) 1 Significant Other Observable Inputs (Level 2) 1 Significant Unobservable Inputs (Level 3) Description Measured on a recurring basis: AFS fixed income securities: U.S. government and government agencies $ 127,089 68,645 58,444 — Foreign government 20,526 — 20,526 — Obligations of states and political subdivisions 1,150,243 — 1,150,243 — Corporate securities 1,678,015 — 1,661,596 16,419 CLO and other ABS 722,240 — 690,948 31,292 CMBS 568,200 — 568,200 — RMBS 1,301,045 — 1,301,045 — Total AFS fixed income securities 5,567,358 68,645 5,451,002 47,711 Equity securities: Common stock 2 160,011 119,977 — — Preferred stock 3,005 3,005 — — Total equity securities 163,016 122,982 — — Short-term investments 290,653 289,232 1,421 — Total assets measured at fair value $ 6,021,027 480,859 5,452,423 47,711 December 31, 2018 Fair Value Measurements Using ($ in thousands) Assets Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) 1 Significant Other Observable Inputs (Level 2) 1 Significant Unobservable Inputs (Level 3) Description Measured on a recurring basis: AFS fixed income securities: U.S. government and government agencies $ 121,310 78,381 42,929 — Foreign government 23,131 — 23,131 — Obligations of states and political subdivisions 1,138,469 — 1,138,469 — Corporate securities 1,617,408 — 1,617,408 — CLO and other ABS 717,362 — 709,953 7,409 CMBS 527,078 — 527,078 — RMBS 1,128,342 — 1,128,342 — Total AFS fixed income securities 5,273,100 78,381 5,187,310 7,409 Equity securities: Common stock 2 144,727 107,397 — — Preferred stock 2,912 2,912 — — Total equity securities 147,639 110,309 — — Short-term investments 323,864 321,370 2,494 — Total assets measured at fair value $ 5,744,603 510,060 5,189,804 7,409 1 There were no transfers of securities between Level 1 and Level 2. 2 Investments amounting to $40.0 million at March 31, 2019 , and $23.7 million at December 31, 2018 , were measured at fair value using net asset value per share (or its practical expedient) and have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to total assets measured at fair value
Schedule of Changes in Fair Value of Securities Using Level 3 Inputs	March 31, 2019 ($ in thousands) Corporate Securities CLO and Other ABS Total Fair value, December 31, 2018 — 7,409 7,409 Total net (losses) gains for the period included in: OCI — (225 ) (225 ) Net income — — — Purchases — 12,434 12,434 Sales — — — Issuances — — — Settlements — — — Transfers into Level 3 16,419 11,674 28,093 Transfers out of Level 3 — — — Fair value, March 31, 2019 16,419 31,292 47,711
Schedule of Quantitative Information of Our Financial Assets and Liabilities That Were Disclosed at Fair Value	March 31, 2019 Fair Value Measurements Using ($ in thousands) Assets/ Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets HTM: Obligations of states and political subdivisions $ 17,923 — 17,923 — Corporate securities 20,019 — 20,019 — Total HTM fixed income securities $ 37,942 — 37,942 — Financial Liabilities Long-term debt: 7.25% Senior Notes $ 61,391 — 61,391 — 6.70% Senior Notes 115,671 — 115,671 — 5.375% Senior Notes 307,215 — 307,215 — 1.61% borrowings from FHLBNY 24,474 — 24,474 — 1.56% borrowings from FHLBNY 24,426 — 24,426 — 3.03% borrowings from FHLBI 61,814 — 61,814 — Total long-term debt $ 594,991 — 594,991 — December 31, 2018 Fair Value Measurements Using ($ in thousands) Assets/ Quoted Prices in Active Markets for Identical Assets/ Liabilities (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Financial Assets HTM: Obligations of states and political subdivisions $ 17,969 — 17,969 — Corporate securities 20,348 — 20,348 — Total HTM fixed income securities $ 38,317 — 38,317 — Financial Liabilities Long-term debt: 7.25% Senior Notes $ 57,032 — 57,032 — 6.70% Senior Notes 107,075 — 107,075 — 5.875% Senior Notes 177,230 177,230 — — 1.61% borrowings from FHLBNY 24,218 — 24,218 — 1.56% borrowings from FHLBNY 24,162 — 24,162 — 3.03% borrowings from FHLBI 58,905 — 58,905 — Total long-term debt $ 448,622 177,230 271,392 —

Reinsurance (Tables)

Reinsurance (Tables)	3 Months Ended
	Mar. 31, 2019
Reinsurance Disclosures [Abstract]
Schedule of List Of Direct, Assumed, And Ceded Reinsurance Amounts	Quarter ended March 31, ($ in thousands) 2019 2018 Premiums written: Direct $ 766,394 714,234 Assumed 6,555 6,271 Ceded (100,002 ) (95,945 ) Net $ 672,947 624,560 Premiums earned: Direct $ 728,037 683,733 Assumed 6,562 6,124 Ceded (102,026 ) (98,029 ) Net $ 632,573 591,828 Loss and loss expenses incurred: Direct $ 424,657 420,916 Assumed 5,265 8,004 Ceded (43,343 ) (43,979 ) Net $ 386,579 384,941
Schedule of Ceded Premiums and Losses Related to Flood Operations	Ceded to NFIP Quarter ended March 31, ($ in thousands) 2019 2018 Ceded premiums written $ (60,013 ) (56,669 ) Ceded premiums earned (62,263 ) (58,991 ) Ceded loss and loss expenses incurred (13,686 ) (15,719 )

Reserve for Loss and Loss Exp_2

Reserve for Loss and Loss Expense (Tables)	3 Months Ended
	Mar. 31, 2019
Insurance Loss Reserves [Abstract]
Schedule of Liability for Unpaid Claims and Claims Adjustment Expense	Quarter ended March 31, ($ in thousands) 2019 2018 Gross reserve for loss and loss expense, at beginning of year $ 3,893,868 3,771,240 Less: reinsurance recoverable on unpaid loss and loss expense, at beginning of year 537,388 585,855 Net reserve for loss and loss expense, at beginning of year 3,356,480 3,185,385 Incurred loss and loss expense for claims occurring in the: Current year 397,253 388,801 Prior years (10,674 ) (3,860 ) Total incurred loss and loss expense 386,579 384,941 Paid loss and loss expense for claims occurring in the: Current year 73,964 79,345 Prior years 246,168 248,738 Total paid loss and loss expense 320,132 328,083 Net reserve for loss and loss expense, at end of period 3,422,927 3,242,243 Add: Reinsurance recoverable on unpaid loss and loss expense, at end of period 543,582 549,837 Gross reserve for loss and loss expense at end of period $ 3,966,509 3,792,080

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Schedule of Revenue By Segment	Revenue by Segment Quarter ended March 31, ($ in thousands) 2019 2018 Standard Commercial Lines: Net premiums earned: Commercial automobile $ 131,186 118,231 Workers compensation 78,715 78,823 General liability 161,525 149,829 Commercial property 86,067 80,326 Businessowners’ policies 26,081 25,591 Bonds 8,904 8,134 Other 4,706 4,430 Miscellaneous income 2,044 1,826 Total Standard Commercial Lines revenue 499,228 467,190 Standard Personal Lines: Net premiums earned: Personal automobile 43,163 40,442 Homeowners 32,130 32,201 Other 2,014 1,613 Miscellaneous income 276 352 Total Standard Personal Lines revenue 77,583 74,608 E&S Lines: Net premiums earned: Casualty lines 44,528 38,540 Property lines 13,554 13,668 Miscellaneous income — 1 Total E&S Lines revenue 58,082 52,209 Investments: Net investment income 50,618 43,231 Net realized and unrealized investment gains (losses) 13,451 (10,549 ) Total Investments revenue 64,069 32,682 Total revenues $ 698,962 626,689
Schedule of Income Before and After Federal Income Tax	Income Before and After Federal Income Tax Quarter ended March 31, ($ in thousands) 2019 2018 Standard Commercial Lines: Underwriting gain, before federal income tax $ 25,815 6,804 Underwriting gain, after federal income tax 20,394 5,375 Combined ratio 94.8 % 98.5 ROE contribution 4.4 1.3 Standard Personal Lines: Underwriting gain (loss), before federal income tax $ 3,167 (1,506 ) Underwriting gain (loss), after federal income tax 2,502 (1,190 ) Combined ratio 95.9 % 102.0 ROE contribution 0.5 (0.3 ) E&S Lines: Underwriting gain (loss), before federal income tax $ 4,579 (565 ) Underwriting gain (loss), after federal income tax 3,617 (446 ) Combined ratio 92.1 % 101.1 ROE contribution 0.8 (0.1 ) Investments: Net investment income $ 50,618 43,231 Net realized and unrealized investment gains (losses) 13,451 (10,549 ) Total investment segment income, before federal income tax 64,069 32,682 Tax on investment segment income 12,120 5,226 Total investment segment income, after federal income tax $ 51,949 27,456 ROE contribution of after-tax net investment income 8.9 8.5
Schedule of Reconciliation of Segment Results to Income Before Federal Income Tax	Reconciliation of Segment Results to Income Before Federal Income Tax Quarter ended March 31, ($ in thousands) 2019 2018 Underwriting gain (loss) Standard Commercial Lines $ 25,815 6,804 Standard Personal Lines 3,167 (1,506 ) E&S Lines 4,579 (565 ) Investment income 64,069 32,682 Total all segments 97,630 37,415 Interest expense (11,526 ) (6,152 ) Corporate expenses (12,410 ) (11,332 ) Income, before federal income tax $ 73,694 19,931

Retirement Plans (Table)

Retirement Plans (Table)	3 Months Ended
	Mar. 31, 2019
Retirement Benefits [Abstract]
Schedule of Components of Net Periodic Benefit Cost	Pension Plan Quarter ended March 31, ($ in thousands) 2019 2018 Net Periodic Benefit Cost: Interest cost $ 3,377 3,095 Expected return on plan assets (5,279 ) (5,682 ) Amortization of unrecognized net actuarial loss 644 494 Total net periodic benefit cost 1 $ (1,258 ) (2,093 ) 1 The components of net periodic benefit cost are included within "Loss and loss expense incurred" and "Other insurance expenses" on the Consolidated Statements of Income.
Schedule of Weighted-Average Expense Assumptions	Pension Plan Quarter ended March 31, 2019 2018 Weighted-Average Expense Assumptions: Discount rate 4.46 % 3.78 % Effective interest rate for calculation of interest cost 4.12 3.46 Expected return on plan assets 6.50 6.36

Comprehensive Income (Tables)

Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2019
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Schedule of Components of Comprehensive Income-Gross and Net of Tax	First Quarter 2019 ($ in thousands) Gross Tax Net Net income $ 73,694 12,346 61,348 Components of OCI: Unrealized gains on investment securities : Unrealized holding gains during the period 102,926 21,613 81,313 Amounts reclassified into net income: HTM securities (9 ) (2 ) (7 ) Realized gains on disposals and OTTI of AFS securities (1,077 ) (226 ) (851 ) Total unrealized gains on investment securities 101,840 21,385 80,455 Defined benefit pension and post-retirement plans: Amounts reclassified into net income: Net actuarial loss 664 139 525 Total defined benefit pension and post-retirement plans 664 139 525 Other comprehensive income 102,504 21,524 80,980 Comprehensive income $ 176,198 33,870 142,328 First Quarter 2018 ($ in thousands) Gross Tax Net Net income $ 19,931 1,006 18,925 Components of other comprehensive loss: Unrealized losses on investment securities : Unrealized holding losses during the period (85,315 ) (17,917 ) (67,398 ) Amounts reclassified into net income: HTM securities (12 ) (2 ) (10 ) Realized losses on disposals and OTTI of AFS securities 4,549 955 3,594 Total unrealized losses on investment securities (80,778 ) (16,964 ) (63,814 ) Defined benefit pension and post-retirement plans: Amounts reclassified into net income: Net actuarial loss 532 112 420 Total defined benefit pension and post-retirement plans 532 112 420 Other comprehensive loss (80,246 ) (16,852 ) (63,394 ) Comprehensive loss $ (60,315 ) (15,846 ) (44,469 )
Schedule of Components of Accumulated Other Comprehensive Income Net of Tax	March 31, 2019 Defined Benefit Pension and Post-Retirement Plans Net Unrealized Gains (Losses) on Investment Securities Total AOCI ($ in thousands) OTTI Related HTM Related All Other Investments Subtotal Balance, December 31, 2018 $ (71 ) 71 1,888 1,888 (79,844 ) (77,956 ) OCI before reclassifications — — 81,313 81,313 — 81,313 Amounts reclassified from AOCI — (7 ) (851 ) (858 ) 525 (333 ) Net current period OCI — (7 ) 80,462 80,455 525 80,980 Balance, March 31, 2019 $ (71 ) 64 82,350 82,343 (79,319 ) 3,024
Schedule of Reclassifications Out Of Accumulated Other Comprehensive Income	Quarter ended March 31, Affected Line Item in the Unaudited Consolidated Statements of Income ($ in thousands) 2019 2018 HTM related Unrealized losses on HTM disposals $ — 1 Net realized and unrealized gains (losses) Amortization of net unrealized gains on HTM securities (9 ) (13 ) Net investment income earned (9 ) (12 ) Income before federal income tax 2 2 Total federal income tax expense (7 ) (10 ) Net income Realized (gains) losses on AFS and OTTI Realized (gains) losses on AFS disposals and OTTI (1,077 ) 4,549 Net realized and unrealized gains (losses) (1,077 ) 4,549 Income before federal income tax 226 (955 ) Total federal income tax expense (851 ) 3,594 Net income Defined benefit pension and post-retirement life plans Net actuarial loss 145 112 Loss and loss expense incurred 519 420 Other insurance expenses Total defined benefit pension and post-retirement life 664 532 Income before federal income tax (139 ) (112 ) Total federal income tax expense 525 420 Net income Total reclassifications for the period $ (333 ) 4,004 Net income

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Components of Lease Expense	($ in thousands) Quarter ended March 31, 2019 Operating lease cost, included in Other insurance expenses on the Consolidated Statements of Income $ 2,152 Finance lease cost: Amortization of assets, included in Other insurance expenses on the Consolidated Statements of Income 284 Interest on lease liabilities, included in Interest expense on the Consolidated Statements of Income — Total finance lease cost 284 Variable lease cost, included in Other insurance expenses on the Consolidated Statements of Income 788 Short-term lease cost, included in Other insurance expenses on the Consolidated Statements of Income 739
Supplemental Lease Information	March 31, 2019 Weighted-average remaining lease term Operating leases 5 years Finance leases 1 Weighted-average discount rate Operating leases 3.3 % Finance leases 1 — 1 Prior to adoption of ASU 2016-02, our historical capital lease liability and asset were measured using an un-discounted cash flow stream due to immateriality of the capital lease population. As we have elected the practical expedient that does not require us to reassess our population of capital leases upon adoption of ASU 2016-02, our existing finance leases do not have a weighted-average discount rate.
Lease Assets and Liabilities	($ in thousands) March 31, 2019 Operating leases Other assets $ 24,946 Other liabilities 25,415 Finance leases Property and equipment - at cost, net of accumulated depreciation and amortization 607 Long-term debt 607
Maturities of Lease Liabilities	($ in thousands) Finance Leases Operating Leases Total Year ended December 31, 2019 (excluding the three months ended March 31, 2019) $ 444 5,779 6,223 2020 141 7,355 7,496 2021 22 5,083 5,105 2022 — 3,641 3,641 2023 — 2,900 2,900 Thereafter — 9,698 9,698 Total lease payments 607 34,456 35,063 Less: imputed interest — 3,610 3,610 Less: leases that have not yet commenced — 5,431 5,431 Total lease liabilities $ 607 25,415 26,022
Schedule of Future Minimum Rental Commitments For Non-Cancelable Leases	($ in thousands) Capital Leases Operating Leases Total 2019 $ 728 7,762 8,490 2020 141 7,355 7,496 2021 22 5,083 5,105 2022 — 3,641 3,641 2023 — 2,900 2,900 Thereafter — 9,698 9,698 Total minimum payment required $ 891 36,439 37,330

Statements of Cash Flow (Cash F

Statements of Cash Flow (Cash Flow Supplemental Disclosures) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Interest		$ 4,477	$ 3,455
Federal income tax		0	(2,807)
Operating cash flows from operating leases	[1]	1,983	0
Financing cash flows from finance leases		284
Repayments of capital lease obligations			734
Assets acquired under operating lease arrangements	[1]	6,136	0
Non-cash purchase of property and equipment		162	0
AFS Fixed Income Securities [Member]
Corporate actions related to securities	[2]	$ 18,447	$ 11,347
[1]	Upon adoption of ASU 2016-02, effective January 1, 2019, we are required to disclose cash paid for amounts included in the measurement of operating lease liabilities, as well as supplemental non-cash information on operating lease liabilities arising from obtaining operating lease assets.
[2]	Examples of such corporate actions include exchanges, non-cash acquisitions, and stock splits.

Statements of Cash Flow (Schedu

Statements of Cash Flow (Schedule of Cash and Restricted Cash) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Schedule of Cash and Restricted Cash [Line Items]
Cash	$ 516	$ 505
Restricted cash	9,998	16,414
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 10,514	$ 16,919	$ 16,932	$ 44,710

Investments (Held-To-Maturity S

Investments (Held-To-Maturity Securities Disclosure) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
HTM Securities Percent of Invested Assets	1.00%	1.00%
HTM, Carrying Value	$ 36,493	$ 37,110
Net unrealized unrecognized gains on held to maturity securities	1,500	1,300
Gross unrealized unrecognized loss	$ 100	$ 200

Investments (Available-For-Sale

Investments (Available-For-Sale Securities Disclosure) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Cost/Amortized Cost	$ 5,463,273	$ 5,270,798
Unrealized Gains	118,373	47,369
Unrealized Losses	(14,288)	(45,067)
AFS securities, fair value	5,567,358	5,273,100
AFS Fixed Income Securities [Member] | U.S. Government and Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Cost/Amortized Cost	125,664	120,092
Unrealized Gains	1,766	1,810
Unrealized Losses	(341)	(592)
AFS securities, fair value	127,089	121,310
AFS Fixed Income Securities [Member] | Foreign Government [Member]
Debt Securities, Available-for-sale [Line Items]
Cost/Amortized Cost	20,238	23,202
Unrealized Gains	299	36
Unrealized Losses	(11)	(107)
AFS securities, fair value	20,526	23,131
AFS Fixed Income Securities [Member] | Obligations of States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Line Items]
Cost/Amortized Cost	1,110,504	1,121,615
Unrealized Gains	39,936	19,485
Unrealized Losses	(197)	(2,631)
AFS securities, fair value	1,150,243	1,138,469
AFS Fixed Income Securities [Member] | Corporate Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Cost/Amortized Cost	1,651,773	1,639,852
Unrealized Gains	32,355	5,521
Unrealized Losses	(6,113)	(27,965)
AFS securities, fair value	1,678,015	1,617,408
AFS Fixed Income Securities [Member] | Collateralized Loan Obligations and Other Asset Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Cost/Amortized Cost	722,573	720,193
Unrealized Gains	5,050	4,112
Unrealized Losses	(5,383)	(6,943)
AFS securities, fair value	722,240	717,362
AFS Fixed Income Securities [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Cost/Amortized Cost	557,148	527,409
Unrealized Gains	11,867	3,417
Unrealized Losses	(815)	(3,748)
AFS securities, fair value	568,200	527,078
AFS Fixed Income Securities [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Cost/Amortized Cost	1,275,373	1,118,435
Unrealized Gains	27,100	12,988
Unrealized Losses	(1,428)	(3,081)
AFS securities, fair value	$ 1,301,045	$ 1,128,342

Investments (Fair Value and Gro

Investments (Fair Value and Gross Pre-Tax Net Unrealized Loss of Securities By Length of Time) (Details) - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Percent Of Securities of Amortized Cost In An Unrealized Unrecognized Loss Position		1.00%	2.00%
AFS Fixed Income Securities [Member]
AFS Fair Value, Less than 12 months		$ 688,988	$ 2,142,433
AFS Unrealized Losses, Less than 12 months	[1]	(7,889)	(36,948)
AFS Fair Value, 12 months or longer		438,135	275,174
AFS Unrealized Losses, 12 months or longer	[1]	(6,399)	(8,119)
AFS Fair Value		1,127,123	2,417,607
AFS Unrealized Losses	[1]	(14,288)	(45,067)
AFS Fixed Income Securities [Member] | U.S. Government and Government Agencies [Member]
AFS Fair Value, Less than 12 months		13,443	6,693
AFS Unrealized Losses, Less than 12 months	[1]	(41)	(174)
AFS Fair Value, 12 months or longer		25,774	23,163
AFS Unrealized Losses, 12 months or longer	[1]	(300)	(418)
AFS Fair Value		39,217	29,856
AFS Unrealized Losses	[1]	(341)	(592)
AFS Fixed Income Securities [Member] | Foreign Government [Member]
AFS Fair Value, Less than 12 months		0	12,208
AFS Unrealized Losses, Less than 12 months	[1]	0	(93)
AFS Fair Value, 12 months or longer		3,509	1,482
AFS Unrealized Losses, 12 months or longer	[1]	(11)	(14)
AFS Fair Value		3,509	13,690
AFS Unrealized Losses	[1]	(11)	(107)
AFS Fixed Income Securities [Member] | Obligations of States and Political Subdivisions [Member]
AFS Fair Value, Less than 12 months		15,257	196,798
AFS Unrealized Losses, Less than 12 months	[1]	(71)	(2,074)
AFS Fair Value, 12 months or longer		21,676	42,821
AFS Unrealized Losses, 12 months or longer	[1]	(126)	(557)
AFS Fair Value		36,933	239,619
AFS Unrealized Losses	[1]	(197)	(2,631)
AFS Fixed Income Securities [Member] | Corporate Securities [Member]
AFS Fair Value, Less than 12 months		158,607	1,041,952
AFS Unrealized Losses, Less than 12 months	[1]	(2,783)	(23,649)
AFS Fair Value, 12 months or longer		160,121	78,953
AFS Unrealized Losses, 12 months or longer	[1]	(3,330)	(4,316)
AFS Fair Value		318,728	1,120,905
AFS Unrealized Losses	[1]	(6,113)	(27,965)
AFS Fixed Income Securities [Member] | Collateralized Loan Obligations and Other Asset Backed Securities [Member]
AFS Fair Value, Less than 12 months		366,775	516,106
AFS Unrealized Losses, Less than 12 months	[1]	(4,231)	(6,750)
AFS Fair Value, 12 months or longer		79,489	16,800
AFS Unrealized Losses, 12 months or longer	[1]	(1,152)	(193)
AFS Fair Value		446,264	532,906
AFS Unrealized Losses	[1]	(5,383)	(6,943)
AFS Fixed Income Securities [Member] | Commercial Mortgage Backed Securities [Member]
AFS Fair Value, Less than 12 months		112,025	229,338
AFS Unrealized Losses, Less than 12 months	[1]	(505)	(2,548)
AFS Fair Value, 12 months or longer		63,774	66,294
AFS Unrealized Losses, 12 months or longer	[1]	(310)	(1,200)
AFS Fair Value		175,799	295,632
AFS Unrealized Losses	[1]	(815)	(3,748)
AFS Fixed Income Securities [Member] | Residential Mortgage Backed Securities [Member]
AFS Fair Value, Less than 12 months		22,881	139,338
AFS Unrealized Losses, Less than 12 months	[1]	(258)	(1,660)
AFS Fair Value, 12 months or longer		83,792	45,661
AFS Unrealized Losses, 12 months or longer	[1]	(1,170)	(1,421)
AFS Fair Value		106,673	184,999
AFS Unrealized Losses	[1]	$ (1,428)	$ (3,081)
[1]	Gross unrealized losses include non-OTTI unrealized amounts and OTTI losses recognized in AOCI.

Investments (Fixed Income Secur

Investments (Fixed Income Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule of Fixed Income Securities [Line Items]
Due in one year or less fair value, AFS	$ 238,650
Due after one year through five years fair value, AFS	2,126,600
Due after five years through 10 years fair value, AFS	3,060,270
Due after 10 years fair value, AFS	141,838
AFS, Fair Value	5,567,358	$ 5,273,100
Due in one year or less carrying value, HTM	12,795
Due after one year through five years carrying value, HTM	17,574
Due after five years through 10 years carrying value, HTM	6,124
Due after 10 years carrying value, HTM	0
HTM, Carrying Value	36,493	37,110
Due in one year or less fair value, HTM	12,927
Due after one year through five years fair value, HTM	18,728
Due after five years through 10 years fair value, HTM	6,287
Due after 10 years fair value, HTM	0
HTM, Fair Value	$ 37,942	$ 38,317

Investments (Other Investment P

Investments (Other Investment Portfolio by Strategy and the Remaining Commitment Amount and Maximum Exposure to Loss Associated With Each Strategy) (Details) - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Carrying Value		$ 176,225	$ 178,938
Other Investments [Member]
Carrying Value		176,225	178,938
Remaining Commitment		217,261	202,270
Maximum Exposure to Loss	[1]	393,486	381,208
Alternative Investments [Member]
Carrying Value		151,733	153,896
Remaining Commitment		217,261	202,270
Maximum Exposure to Loss	[1]	368,994	356,166
Private Equity [Member] | Alternative Investments [Member]
Carrying Value		92,371	84,352
Remaining Commitment		101,297	93,688
Maximum Exposure to Loss	[1]	193,668	178,040
Private Credit [Member] | Alternative Investments [Member]
Carrying Value		30,518	41,682
Remaining Commitment		90,812	81,453
Maximum Exposure to Loss	[1]	121,330	123,135
Real Assets [Member] | Alternative Investments [Member]
Carrying Value		28,844	27,862
Remaining Commitment		25,152	27,129
Maximum Exposure to Loss	[1]	53,996	54,991
Other Securities [Member]
Carrying Value		24,492	25,042
Remaining Commitment		0	0
Maximum Exposure to Loss	[1]	$ 24,492	$ 25,042
[1]	The maximum exposure to loss includes both the carry value of these investments and the related unfunded commitments. In addition, tax credits that have been previously recognized in Other securities are subject to the risk of recapture, which we do not consider significant.

Investments (Aggregated Income

Investments (Aggregated Income Statement Summarized Financial Information for Partnerhips in our Alternative Investment Portfolio) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Schedule of Equity Method Investments [Line Items]
Net investment income earned	$ 50,618	$ 43,231
Alternative Investments [Member]
Schedule of Equity Method Investments [Line Items]
Net investment income earned	600	1,600
Investments accounted for under the equity method [Member]
Schedule of Equity Method Investments [Line Items]
Net investment income (loss)	(150,100)	(56,200)
Realized gains (losses)	143,300	1,003,000
Net change in unrealized appreciation	554,300	96,200
Net gain	$ 547,500	$ 1,043,000

Investments (Investments Pledge

Investments (Investments Pledged as Collateral) (Details) $ in Millions	Mar. 31, 2019USD ($)
Financial Instruments Owned and Pledged as Collateral [Line Items]
Carrying Value Bonds On Deposit With Various State And Regulatory Agencies	$ 26.7
Securities Pledged As Collateral	208.6
U.S. Government and Government Agencies [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Carrying Value Bonds On Deposit With Various State And Regulatory Agencies	22.5
Securities Pledged As Collateral	22.5
Obligations of States and Political Subdivisions [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Carrying Value Bonds On Deposit With Various State And Regulatory Agencies	3.9
Securities Pledged As Collateral	3.9
Corporate Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Carrying Value Bonds On Deposit With Various State And Regulatory Agencies	0.3
Securities Pledged As Collateral	0.3
Commercial Mortgage Backed Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Carrying Value Bonds On Deposit With Various State And Regulatory Agencies	0
Securities Pledged As Collateral	28
Residential Mortgage Backed Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Carrying Value Bonds On Deposit With Various State And Regulatory Agencies	0
Securities Pledged As Collateral	153.9
Federal Home Loan Bank of Indianapolis [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	64.5
Federal Home Loan Bank of Indianapolis [Member] | U.S. Government and Government Agencies [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	0
Federal Home Loan Bank of Indianapolis [Member] | Obligations of States and Political Subdivisions [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	0
Federal Home Loan Bank of Indianapolis [Member] | Corporate Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	0
Federal Home Loan Bank of Indianapolis [Member] | Commercial Mortgage Backed Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	7.2
Federal Home Loan Bank of Indianapolis [Member] | Residential Mortgage Backed Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	57.3
Federal Home Loan Bank of New York [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	117.4
Federal Home Loan Bank of New York [Member] | U.S. Government and Government Agencies [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	0
Federal Home Loan Bank of New York [Member] | Obligations of States and Political Subdivisions [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	0
Federal Home Loan Bank of New York [Member] | Corporate Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	0
Federal Home Loan Bank of New York [Member] | Commercial Mortgage Backed Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	20.8
Federal Home Loan Bank of New York [Member] | Residential Mortgage Backed Securities [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Fixed Income Securities Pledged For FHLB Collateral	$ 96.6

Investments (Credit Concentrati

Investments (Credit Concentration Risk) (Details)	Mar. 31, 2019	Dec. 31, 2018
Investments [Abstract]
Maximum exposure to credit concentration risk of the Company's stockholder's equity other than certain U.S. government-backed investments	10.00%	10.00%

Investments (Net Investment Inc

Investments (Net Investment Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net Investment Income [Line Items]
Net investment income earned	$ 50,618	$ 43,231
Fixed Income Securities [Member]
Net Investment Income [Line Items]
Net investment income earned	49,033	42,041
Equity Securities [Member]
Net Investment Income [Line Items]
Net investment income earned	1,640	1,977
Short-Term Investments [Member]
Net Investment Income [Line Items]
Net investment income earned	2,044	523
Other Investments [Member]
Net Investment Income [Line Items]
Net investment income earned	660	1,563
Investment Expenses [Member]
Net Investment Income [Line Items]
Net investment income earned	$ (2,759)	$ (2,873)

Investments (OTTI) (Details)

Investments (OTTI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Investments [Abstract]
OTTI Charges	$ 104	$ 1,212

Investments (Components Of Net

Investments (Components Of Net Realized and Unrealized Gains and Losses (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Gain (Loss) on Securities [Line Items]
Total net realized gains on the disposal of securities (excluding OTTI charges)		$ 3,444	$ 4,731
OTTI Charges		(104)	(1,212)
Net realized gains		3,340	3,519
Unrealized gains (losses) recognized in income on equity securities	[1]	10,111	(14,068)
Net realized and unrealized gains (losses)		13,451	(10,549)
Unrealized holding gains (losses) on equity securities		12,000	(5,100)
Unrealized losses on equity securities sold during the period		(1,900)	(9,000)
Fixed Income Securities [Member]
Gain (Loss) on Securities [Line Items]
Net realized (losses) gains on disposals of securities, fixed income securities (excluding OTTI charges)		1,143	(3,335)
Equity Securities [Member]
Gain (Loss) on Securities [Line Items]
Total net realized gains on the disposal of securities (excluding OTTI charges)		2,280	8,069
Short-Term Investments [Member]
Gain (Loss) on Securities [Line Items]
Total net realized gains on the disposal of securities (excluding OTTI charges)		14	(3)
Other Investments [Member]
Gain (Loss) on Securities [Line Items]
Total net realized gains on the disposal of securities (excluding OTTI charges)		$ 7	$ 0
[1]	Includes unrealized holding gains (losses) of: (i) $12.0 million in First Quarter 2019 and $(5.1) million in First Quarter 2018 on equity securities remaining in our portfolio as of March 31, 2019 and 2018, respectively; and (ii) $(1.9) million in First Quarter 2019 and $(9.0) million in First Quarter 2018 on equity securities sold in each respective period.

Investments (Net Realized Gains

Investments (Net Realized Gains (Losses) on Disposals) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Schedule of Realized Gains (Losses) on Disposals Excluding OTTI [Line Items]
HTM fixed income securities Gains	$ 0	$ 2
HTM fixed income securities Losses	0	0
Equity securities Gains	2,280	8,399
Equity securities Losses	0	(330)
Short-term investments Gains	14	1
Short-term investments Losses	0	(4)
Other investments Gains	7	0
Other investments Losses	0	0
Net realized investment gains on disposals	3,444	4,731
Proceeds from sale of fixed income securities, AFS	218,411	675,396
Proceeds from sale of equity securities	3,721	40,740
Fixed Maturities [Member]
Schedule of Realized Gains (Losses) on Disposals Excluding OTTI [Line Items]
AFS securities Gains	1,844	2,623
AFS securities Losses	(701)	(5,960)
Equity Securities [Member]
Schedule of Realized Gains (Losses) on Disposals Excluding OTTI [Line Items]
Net realized investment gains on disposals	$ 2,280	$ 8,069

Indebtedness (Schedule of Outst

Indebtedness (Schedule of Outstanding Debt) (Details) - USD ($) $ in Thousands	Mar. 31, 2019		Jan. 01, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Original Amount	$ 745,000
Debt Discount and Unamortized Issuance Cost	10,503
Finance lease liabilities	607	[1]	$ 900	$ 0	[1]
Long-term debt	$ 550,104			439,540
Five Point Three Hundred Seventy Five Senior Notes [Member]
Debt Instrument [Line Items]
Interest Rate	5.375%
Original Amount	$ 300,000
Debt Discount and Unamortized Issuance Cost	9,293
Long term debt, excluding debt discount and debt issuance cost	$ 290,707			0
Five Point Eight Hundred Seventy Five Senior Notes [Member]
Debt Instrument [Line Items]
Interest Rate	5.875%
Original Amount	$ 185,000
Debt Discount and Unamortized Issuance Cost	0
Long term debt, excluding debt discount and debt issuance cost	$ 0			180,771
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member]
Debt Instrument [Line Items]
Interest Rate	3.03%
Original Amount	$ 60,000
Debt Discount and Unamortized Issuance Cost	0
Long term debt, excluding debt discount and debt issuance cost	$ 60,000			60,000
One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	1.56%
Original Amount	$ 25,000
Debt Discount and Unamortized Issuance Cost	0
Long term debt, excluding debt discount and debt issuance cost	$ 25,000			25,000
One Point Sixty One Percent Borrowing From Federal Home Loan Bank Due July 21, 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	1.61%
Original Amount	$ 25,000
Debt Discount and Unamortized Issuance Cost	0
Long term debt, excluding debt discount and debt issuance cost	$ 25,000			25,000
Six Point Seventy Percent Senior Notes [Member]
Debt Instrument [Line Items]
Interest Rate	6.70%
Original Amount	$ 100,000
Debt Discount and Unamortized Issuance Cost	917
Long term debt, excluding debt discount and debt issuance cost	$ 99,083			99,069
Seven Point Twenty Five Percent Senior Notes [Member]
Debt Instrument [Line Items]
Interest Rate	7.25%
Original Amount	$ 50,000
Debt Discount and Unamortized Issuance Cost	293
Long term debt, excluding debt discount and debt issuance cost	$ 49,707			$ 49,700
[1]	Concurrent with the adoption of ASU 2016-02 discussed in Note 2. "Adoption of Accounting Pronouncements," finance lease obligations are now captured in Long-term debt on our Consolidated Balance Sheets.

Indebtedness (Short Term Debt A

Indebtedness (Short Term Debt Activity) (Details) - Two Point Sixty Four Percent Borrowing from Federal Home Loan Bank Due March 28, 2019 [Member] $ in Millions	Mar. 31, 2019USD ($)
Short-term Debt [Line Items]
Federal Home Loan Bank Advances	$ 50
Federal Home Loan Bank, Advances, Interest Rate	2.64%

Indebtedness (Long Term Debt Ac

Indebtedness (Long Term Debt Activity) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 745,000
Net Proceeds from Debt Offering	341,256	$ 130,000
Five Point Three Hundred Seventy Five Senior Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 300,000
Interest Rate	5.375%
Debt Discount	$ 5,900
Unamortized Debt Issuance Expense	3,400
Net Proceeds from Debt Offering	290,700
Proceeds from Debt Issuance, After Redemption	106,000
Five Point Eight Hundred Seventy Five Senior Notes [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 185,000
Interest Rate	5.875%
Debt Retirement Costs, Before Tax	$ 4,200
Debt Retirement Costs, Net of Tax	$ 3,300

Fair Value Measurements (Carryi

Fair Value Measurements (Carrying Values and Estimated Fair Values of Financial Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019		Jan. 01, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 550,104			$ 439,540
Long-term debt, fair value	594,991			448,622
Finance lease liabilities	607	[1]	$ 900	0	[1]
Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	61,391			57,032
Seven Point Twenty Five Percent Senior Notes [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	49,907			49,907
Six Point Seventy Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	115,671			107,075
Six Point Seventy Percent Senior Notes [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	99,467			99,462
Five Point Eight Hundred Seventy Five Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0			177,230
Five Point Eight Hundred Seventy Five Senior Notes [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	0			185,000
Five Point Three Hundred Seventy Five Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	307,215			0
Five Point Three Hundred Seventy Five Senior Notes [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	294,097			0
One Point Sixty One Percent Borrowing From Federal Home Loan Bank Due July 21, 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	24,474			24,218
One Point Sixty One Percent Borrowing From Federal Home Loan Bank Due July 21, 2021 [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	25,000			25,000
One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	24,426			24,162
One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	25,000			25,000
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	61,814			58,905
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	60,000			60,000
Long Term Debt Excluding Issuance Costs and Finance Lease Obligations [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	553,471			444,369
Unamortized Debt Issuance Costs [Member] | Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Unamortized debt issuance costs	$ (3,974)			$ (4,829)
[1]	Concurrent with the adoption of ASU 2016-02 discussed in Note 2. "Adoption of Accounting Pronouncements," finance lease obligations are now captured in Long-term debt on our Consolidated Balance Sheets.

Fair Value Measurements (Quanti

Fair Value Measurements (Quantitative Disclosures of Fair Value Assets) (Details) - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
AFS Fixed Income Securities		$ 5,567,358	$ 5,273,100
Short-term investments		290,653	323,864
Net Asset Value		40,000	23,700
Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		5,567,358	5,273,100
Equity securities		163,016	147,639
Short-term investments		290,653	323,864
Total assets measured at fair value		6,021,027	5,744,603
U.S. Government and Government Agencies [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		127,089	121,310
Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		20,526	23,131
Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		1,150,243	1,138,469
Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		1,678,015	1,617,408
Collateralized Loan Obligations and Other Asset Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		722,240	717,362
Commercial Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		568,200	527,078
Residential Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		1,301,045	1,128,342
Common Stock [Member] | Fair Value, Measurements, Recurring [Member]
Equity securities	[1]	160,011	144,727
Preferred Stock [Member] | Fair Value, Measurements, Recurring [Member]
Equity securities		3,005	2,912
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	68,645	78,381
Equity securities	[2]	122,982	110,309
Short-term investments	[2]	289,232	321,370
Total assets measured at fair value	[2]	480,859	510,060
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | U.S. Government and Government Agencies [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	68,645	78,381
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Collateralized Loan Obligations and Other Asset Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Commercial Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Residential Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Common Stock [Member] | Fair Value, Measurements, Recurring [Member]
Equity securities	[1],[2]	119,977	107,397
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Preferred Stock [Member] | Fair Value, Measurements, Recurring [Member]
Equity securities	[2]	3,005	2,912
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	5,451,002	5,187,310
Equity securities	[2]	0	0
Short-term investments	[2]	1,421	2,494
Total assets measured at fair value	[2]	5,452,423	5,189,804
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government and Government Agencies [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	58,444	42,929
Significant Other Observable Inputs (Level 2) [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	20,526	23,131
Significant Other Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	1,150,243	1,138,469
Significant Other Observable Inputs (Level 2) [Member] | Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	1,661,596	1,617,408
Significant Other Observable Inputs (Level 2) [Member] | Collateralized Loan Obligations and Other Asset Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	690,948	709,953
Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	568,200	527,078
Significant Other Observable Inputs (Level 2) [Member] | Residential Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities	[2]	1,301,045	1,128,342
Significant Other Observable Inputs (Level 2) [Member] | Common Stock [Member] | Fair Value, Measurements, Recurring [Member]
Equity securities	[1],[2]	0	0
Significant Other Observable Inputs (Level 2) [Member] | Preferred Stock [Member] | Fair Value, Measurements, Recurring [Member]
Equity securities	[2]	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		47,711	7,409
Equity securities		0	0
Short-term investments		0	0
Total assets measured at fair value		47,711	7,409
Significant Unobservable Inputs (Level 3) [Member] | U.S. Government and Government Agencies [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		16,419	0
Significant Unobservable Inputs (Level 3) [Member] | Collateralized Loan Obligations and Other Asset Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		31,292	7,409
Significant Unobservable Inputs (Level 3) [Member] | Commercial Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Residential Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
AFS Fixed Income Securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Common Stock [Member] | Fair Value, Measurements, Recurring [Member]
Equity securities	[1]	0	0
Significant Unobservable Inputs (Level 3) [Member] | Preferred Stock [Member] | Fair Value, Measurements, Recurring [Member]
Equity securities		$ 0	$ 0
[1]	Investments amounting to $40.0 million at March 31, 2019, and $23.7 million at December 31, 2018, were measured at fair value using net asset value per share (or its practical expedient) and have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to total assets measured at fair value.
[2]	There were no transfers of securities between Level 1 and Level 2.

Fair Value Measurements (Change

Fair Value Measurements (Change in Fair Value of Securities Using Level 3 Inputs) (Details) - Available-for-sale Securities [Member] $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Corporate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, December 31, 2018	$ 0
Total net (losses) gains for the period included in OCI	0
Total net (losses) gains for the period included in net income	0
Purchases	0
Sales	0
Issuances	0
Settlements	0
Transfers into Level 3	16,419
Transfers out of Level 3	0
Fair value, March 31, 2019	16,419
Collateralized Loan Obligations and Other Asset Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, December 31, 2018	7,409
Total net (losses) gains for the period included in OCI	(225)
Total net (losses) gains for the period included in net income	0
Purchases	12,434
Sales	0
Issuances	0
Settlements	0
Transfers into Level 3	11,674
Transfers out of Level 3	0
Fair value, March 31, 2019	31,292
Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, December 31, 2018	7,409
Total net (losses) gains for the period included in OCI	(225)
Total net (losses) gains for the period included in net income	0
Purchases	12,434
Sales	0
Issuances	0
Settlements	0
Transfers into Level 3	28,093
Transfers out of Level 3	0
Fair value, March 31, 2019	$ 47,711

Fair Value Measurements (Quan_2

Fair Value Measurements (Quantitative Information of Our Financial Assets and Liabilities That Were Disclosed at Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	$ 37,942	$ 38,317
Long-term debt, fair value	594,991	448,622
Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	61,391	57,032
Six Point Seventy Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	115,671	107,075
Five Point Three Hundred Seventy Five Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	307,215	0
Five Point Eight Hundred Seventy Five Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	177,230
One Point Sixty One Percent Borrowing From Federal Home Loan Bank Due July 21, 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	24,474	24,218
One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	24,426	24,162
Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	61,814	58,905
Long-term Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	594,991	448,622
Obligations of States and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	17,923	17,969
Corporate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	20,019	20,348
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	0	0
Long-term debt, fair value	0	177,230
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Six Point Seventy Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Five Point Three Hundred Seventy Five Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Five Point Eight Hundred Seventy Five Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value		177,230
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | One Point Sixty One Percent Borrowing From Federal Home Loan Bank Due July 21, 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Corporate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	37,942	38,317
Long-term debt, fair value	594,991	271,392
Significant Other Observable Inputs (Level 2) [Member] | Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	61,391	57,032
Significant Other Observable Inputs (Level 2) [Member] | Six Point Seventy Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	115,671	107,075
Significant Other Observable Inputs (Level 2) [Member] | Five Point Three Hundred Seventy Five Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	307,215
Significant Other Observable Inputs (Level 2) [Member] | Five Point Eight Hundred Seventy Five Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value		0
Significant Other Observable Inputs (Level 2) [Member] | One Point Sixty One Percent Borrowing From Federal Home Loan Bank Due July 21, 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	24,474	24,218
Significant Other Observable Inputs (Level 2) [Member] | One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	24,426	24,162
Significant Other Observable Inputs (Level 2) [Member] | Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	61,814	58,905
Significant Other Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	17,923	17,969
Significant Other Observable Inputs (Level 2) [Member] | Corporate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	20,019	20,348
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	0	0
Long-term debt, fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Seven Point Twenty Five Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Six Point Seventy Percent Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Five Point Three Hundred Seventy Five Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0
Significant Unobservable Inputs (Level 3) [Member] | Five Point Eight Hundred Seventy Five Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value		0
Significant Unobservable Inputs (Level 3) [Member] | One Point Fifty Six Percent Borrowing From Federal Home Loan Bank Due August 16, 2021 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Three Point Zero Three Percent Borrowing From Federal Home Loan Bank Due December 16, 2026 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Obligations of States and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities, fair value	$ 0	$ 0

Reinsurance (List of Direct, As

Reinsurance (List of Direct, Assumed, and Ceded Reinsurance Amounts) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Premiums written:
Direct	$ 766,394	$ 714,234
Assumed	6,555	6,271
Ceded	(100,002)	(95,945)
Net	672,947	624,560
Premiums earned:
Direct	728,037	683,733
Assumed	6,562	6,124
Ceded	(102,026)	(98,029)
Net	632,573	591,828
Loss and loss expenses incurred:
Direct	424,657	420,916
Assumed	5,265	8,004
Ceded	(43,343)	(43,979)
Net	$ 386,579	$ 384,941

Reinsurance (Ceded Premiums and

Reinsurance (Ceded Premiums and Losses Related to Flood Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Ceded premiums written	$ (100,002)	$ (95,945)
Ceded premiums earned	(102,026)	(98,029)
Ceded loss and loss expenses incurred	$ (43,343)	(43,979)
National Flood Insurance Program [Member]
Percentage of NFIP claims ceded by federal government	100.00%
Ceded premiums written	$ (60,013)	(56,669)
Ceded premiums earned	(62,263)	(58,991)
Ceded loss and loss expenses incurred	$ (13,686)	$ (15,719)

Reserve for Loss and Loss Exp_3

Reserve for Loss and Loss Expense (Rollforward of Reserve for Loss and Loss Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Gross reserve for loss and loss expense, at beginning of year	$ 3,893,868	$ 3,771,240
Less: reinsurance recoverable on unpaid loss and loss expense, at beginning of year	537,388	585,855
Net reserve for loss and loss expense, at beginning of year	3,356,480	3,185,385
Incurred loss and loss expense for claims occurring in the current year	397,253	388,801
Total incurred loss and loss expense	386,579	384,941
Paid loss and loss expense for claims occurring in the current year	73,964	79,345
Paid loss and loss expense for claims occurring in the prior years	246,168	248,738
Total paid loss and loss expense	320,132	328,083
Net reserve for loss and loss expense, at end of period	3,422,927	3,242,243
Add: reinsurance recoverable on unpaid loss and loss expense, at end of period	543,582	549,837
Gross reserve for loss and loss expense, at end of period	3,966,509	3,792,080
Change in Historical Claim Rate Experience [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year development	(10,674)	(3,860)
Casualty Insurance Product Line [Member] | Change in Historical Claim Rate Experience [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year development		(8,000)
Property Insurance Product Line [Member] | Change in Historical Claim Rate Experience [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year development		4,100
Workers Compensation [Member] | Casualty Insurance Product Line [Member] | Change in Historical Claim Rate Experience [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year development	(8,000)	(16,000)
General Liability [Member] | Casualty Insurance Product Line [Member] | Change in Historical Claim Rate Experience [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year development	$ (2,000)
Commercial Automobile [Member] | Casualty Insurance Product Line [Member] | Change in Historical Claim Rate Experience [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
Prior year development		$ 8,000

Segment Information Narrative (

Segment Information Narrative (Details)	3 Months Ended
	Mar. 31, 2019
Number of Operating Segments	4

Segment Information (Revenue by

Segment Information (Revenue by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Total net premiums earned	$ 632,573	$ 591,828
Other income	2,320	2,179
Net investment income	50,618	43,231
Net realized and unrealized investment gains (losses)	13,451	(10,549)
Total investment revenues	64,069	32,682
Total revenues	698,962	626,689
Standard Commercial Lines [Member]
Segment Reporting Information [Line Items]
Other income	2,044	1,826
Total revenues	499,228	467,190
Standard Commercial Lines [Member] | Commercial Automobile [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	131,186	118,231
Standard Commercial Lines [Member] | Workers Compensation [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	78,715	78,823
Standard Commercial Lines [Member] | General Liability [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	161,525	149,829
Standard Commercial Lines [Member] | Commercial Property [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	86,067	80,326
Standard Commercial Lines [Member] | Business Owners' Policies [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	26,081	25,591
Standard Commercial Lines [Member] | Bonds Segment [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	8,904	8,134
Standard Commercial Lines [Member] | Other Commercial [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	4,706	4,430
Standard Personal Lines [Member]
Segment Reporting Information [Line Items]
Other income	276	352
Total revenues	77,583	74,608
Standard Personal Lines [Member] | Personal Automobile [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	43,163	40,442
Standard Personal Lines [Member] | Homeowners [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	32,130	32,201
Standard Personal Lines [Member] | Other Personal [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	2,014	1,613
Excess And Surplus Operations [Member]
Segment Reporting Information [Line Items]
Other income	0	1
Total revenues	58,082	52,209
Excess And Surplus Operations [Member] | Casualty Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	44,528	38,540
Excess And Surplus Operations [Member] | Property Insurance Product Line [Member]
Segment Reporting Information [Line Items]
Total net premiums earned	$ 13,554	$ 13,668

Segment Information (Income Bef

Segment Information (Income Before and After Federal Income Tax) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Net investment income	$ 50,618	$ 43,231
Net realized and unrealized investment gains (losses)	13,451	(10,549)
Total investment income, before federal income tax	64,069	32,682
Tax on investment income	12,120	5,226
Total investment income, after federal income tax	51,949	27,456
Standard Commercial Lines [Member]
Segment Reporting Information [Line Items]
Underwriting gain (loss), before federal income tax	25,815	6,804
Underwriting gain (loss), after federal income tax	$ 20,394	$ 5,375
Combined ratio	94.80%	98.50%
ROE Contribution	4.40%	1.30%
Standard Personal Lines [Member]
Segment Reporting Information [Line Items]
Underwriting gain (loss), before federal income tax	$ 3,167	$ (1,506)
Underwriting gain (loss), after federal income tax	$ 2,502	$ (1,190)
Combined ratio	95.90%	102.00%
ROE Contribution	0.50%	(0.30%)
Excess And Surplus Operations [Member]
Segment Reporting Information [Line Items]
Underwriting gain (loss), before federal income tax	$ 4,579	$ (565)
Underwriting gain (loss), after federal income tax	$ 3,617	$ (446)
Combined ratio	92.10%	101.10%
ROE Contribution	0.80%	(0.10%)
Investments [Member]
Segment Reporting Information [Line Items]
ROE Contribution	8.90%	8.50%

Segment Information (Reconcilia

Segment Information (Reconciliation of Segment Results to Income Before Federal Income Tax (Details)) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Investment income, before federal income tax	$ 64,069	$ 32,682
Interest expense	(11,526)	(6,152)
Corporate expenses	(12,410)	(11,332)
Income before federal income tax	73,694	19,931
Standard Commercial Lines [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Underwriting gain (loss), before federal income tax	25,815	6,804
Standard Personal Lines [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Underwriting gain (loss), before federal income tax	3,167	(1,506)
Excess And Surplus Operations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Underwriting gain (loss), before federal income tax	4,579	(565)
Operating Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Total income, before federal income tax all segments	$ 97,630	$ 37,415

Retirement Plans (Components of

Retirement Plans (Components of Net Periodic Benefit Cost) (Details) - Pension Plan [Member] - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost		$ 3,377	$ 3,095
Expected return on plan assets		(5,279)	(5,682)
Amortization of unrecognized net actuarial loss		644	494
Total net periodic benefit	[1]	$ (1,258)	$ (2,093)
[1]	The components of net periodic benefit cost are included within "Loss and loss expense incurred" and "Other insurance expenses" on the Consolidated Statements of Income.

Retirement Plans (Weighted-Aver

Retirement Plans (Weighted-Average Expense Assumptions) (Details) - Pension Plan [Member]	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.46%	3.78%
Effective interest rate for calculation of interest cost	4.12%	3.46%
Expected return on plan assets	6.50%	6.36%

Comprehensive Income (Component

Comprehensive Income (Components of Comprehensive Income-Gross and Net of Tax) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net income, Gross	$ 73,694	$ 19,931
Unrealized holding (losses) gains during the period, Gross	102,926	(85,315)
Amounts reclassified into net income: HTM securities, Gross	(9)	(12)
Amounts reclassified into net income: Realized (gains) losses on disposals and OTTI of AFS securities, Gross	(1,077)	4,549
Total unrealized gains (losses) on investment securities, Gross	101,840	(80,778)
Amount reclassified into net income: Net actuarial loss, Gross	664	532
Total defined pension and other post-retirement benefit plans, Gross	664	532
Other comprehensive income (loss), Gross	102,504	(80,246)
Comprehensive income (loss) before tax	176,198	(60,315)
Net income, Tax	12,346	1,006
Unrealized holding (losses) gains during the period, Tax	21,613	(17,917)
Amounts reclassified into net income: HTM securities, Tax	(2)	(2)
Amounts reclassified into net income: Realized (gains) losses on disposals and OTTI of AFS securities, Tax	(226)	955
Total unrealized gains (losses) on investment securities, Tax	21,385	(16,964)
Amount reclassified into net income: Net actuarial loss, Tax	139	112
Total defined pension and other post-retirement benefit plans, Tax	139	112
Other comprehensive income (loss), Tax	21,524	(16,852)
Comprehensive income (loss), Tax	33,870	(15,846)
Net income	61,348	18,925
Unrealized holding (losses) gains arising during period	81,313	(67,398)
Amounts reclassified into net income: HTM Securities	(7)	(10)
Amounts reclassified into net income: Realized (gains) losses on disposals and OTTI of available-for-sale securities	(851)	3,594
Total unrealized gains (losses) on investment securities	80,455	(63,814)
Amount reclassified into net income: Net actuarial loss	525	420
Total defined benefit pension and post-retirement plans	525	420
Other comprehensive income (loss)	80,980	(63,394)
Comprehensive income (loss)	$ 142,328	$ (44,469)

Comprehensive Income (Compone_2

Comprehensive Income (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2018	$ (77,956)
Amounts reclassified from AOCI, Non-credit OTTI	0
Amounts reclassified from AOCI, HTM related	(7)	$ (10)
Amounts reclassified from AOCI, All Other	(851)	3,594
OCI before reclassifications, Defined Benefit Pension and Post Retirement Plans	0
Amount reclassified into net income: Net actuarial loss	525	420
Other comprehensive income	80,980	(63,394)
Other comprehensive income, defined pension and post retirement plans	525	420
Ending Balance, March 31, 2019	3,024
Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2018	1,888
OCI before reclassifications	81,313
Other comprehensive income	80,462
Ending Balance, March 31, 2019	82,350
Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2018	1,888
OCI before reclassifications	81,313
Amounts reclassified from AOCI	(858)
Other comprehensive income	80,455
Ending Balance, March 31, 2019	82,343
Accumulated Other-than-Temporary Impairment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2018	(71)
OCI before reclassifications	0
Other comprehensive income	0
Ending Balance, March 31, 2019	(71)
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Held-to-maturity Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2018	71
OCI before reclassifications	0
Other comprehensive income	(7)
Ending Balance, March 31, 2019	64
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2018	(79,844)
Amount reclassified into net income: Net actuarial loss	525
Ending Balance, March 31, 2019	(79,319)
Accumulated other comprehensive income (loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance, December 31, 2018	(77,956)
OCI before reclassifications	81,313
Amounts reclassified from AOCI	(333)
Other comprehensive income	80,980	$ (63,394)
Ending Balance, March 31, 2019	$ 3,024

Comprehensive Income (Reclassif

Comprehensive Income (Reclassification out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net realized and unrealized gains (losses)	$ 13,451	$ (10,549)
Net investment income	50,618	43,231
Loss and loss expense incurred	386,579	384,941
Other insurance expenses	85,079	83,240
Income before federal income tax	73,694	19,931
Total federal income tax expense	(12,346)	(1,006)
Net income	61,348	18,925
Reclassification out of AOCI
Net income	(333)	4,004
Pension Plan [Member] | Reclassification out of AOCI
Loss and loss expense incurred	145	112
Other insurance expenses	519	420
Income before federal income tax	664	532
Total federal income tax expense	(139)	(112)
Net income	525	420
Held-to-maturity Securities [Member] | Reclassification out of AOCI
Net realized and unrealized gains (losses)	0	1
Net investment income	(9)	(13)
Income before federal income tax	(9)	(12)
Total federal income tax expense	2	2
Net income	(7)	(10)
Available-for-sale Securities [Member] | Reclassification out of AOCI
Net realized and unrealized gains (losses)	(1,077)	4,549
Income before federal income tax	(1,077)	4,549
Total federal income tax expense	226	(955)
Net income	$ (851)	$ 3,594

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Thousands	Mar. 31, 2019		Jan. 01, 2019	Dec. 31, 2018	[1]	Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use asset	$ 24,946		$ 20,700
Operating lease liability	25,415		21,000
Finance lease right-of-use asset	607		900
Finance lease liabilities	607	[1]	900	$ 0
Retained Earnings [Member] | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption	$ 342		$ 342			$ 0
[1]	Concurrent with the adoption of ASU 2016-02 discussed in Note 2. "Adoption of Accounting Pronouncements," finance lease obligations are now captured in Long-term debt on our Consolidated Balance Sheets.

Leases (Components of Lease Exp

Leases (Components of Lease Expense) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Lease Expense [Line Items]
Operating lease cost	$ 2,152
Finance lease cost: Amortization of assets	284
Finance lease cost: Interest on lease liabilities	0
Total finance lease cost	284
Variable lease cost	788
Short-term lease cost	$ 739

Leases (Supplemental Lease Info

Leases (Supplemental Lease Information) (Details)	Mar. 31, 2019
Supplemental Lease Information [Line Items]
Weighted average remaining lease term, operating leases	5 years
Weighted average remaining lease term, finance leases	1 year
Weighted average discount rate, operating leases	3.30%
Weighted average discount rate, finance leases	0.00%	[1]
[1]	Prior to adoption of ASU 2016-02, our historical capital lease liability and asset were measured using an un-discounted cash flow stream due to immateriality of the capital lease population. As we have elected the practical expedient that does not require us to reassess our population of capital leases upon adoption of ASU 2016-02, our existing finance leases do not have a weighted-average discount rate.

Leases (Lease Assets and Liabil

Leases (Lease Assets and Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019		Jan. 01, 2019	Dec. 31, 2018	[1]
Lease Assets and Liabilities [Line Items]
Operating leases, Other assets	$ 24,946		$ 20,700
Operating leases, Other liabilities	25,415		21,000
Finance leases, Property and equipment - at cost, net of accumulated depreciation and amortization	607		900
Finance leases, Long-term debt	$ 607	[1]	$ 900	$ 0
[1]	Concurrent with the adoption of ASU 2016-02 discussed in Note 2. "Adoption of Accounting Pronouncements," finance lease obligations are now captured in Long-term debt on our Consolidated Balance Sheets.

Leases (Maturities of Lease Lia

Leases (Maturities of Lease Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019		Jan. 01, 2019	Dec. 31, 2018
Lease Liabilities Payments Due [Line Items]
Finance lease liability, due remainder of fiscal year	$ 444
Finance lease liability, due 2020	141
Finance lease liability, due 2021	22
Finance lease liability, due 2022	0
Finance lease liability, due 2023	0
Finance lease liability, due after 2023	0
Finance lease liability, total payments	607
Finance lease imputed interest	0
Finance leases not yet commenced	0
Finance lease liabilities	607	[1]	$ 900	$ 0	[1]
Operating lease liability, due remainder of fiscal year	5,779
Operating lease liability, due 2020	7,355
Operating lease liability, due 2021	5,083
Operating lease liability, due 2022	3,641
Operating lease liability, due 2023	2,900
Operating lease liability, due after 2023	9,698
Operating lease liability, total payments	34,456
Operating lease imputed interest	3,610
Operating leases not yet commenced	5,431
Operating lease liability	25,415		$ 21,000
Total lease liability, due remainder of fiscal year	6,223			8,490
Total lease liability, due 2020	7,496			7,496
Total lease liability, due 2021	5,105			5,105
Total lease liability, due 2022	3,641			3,641
Total lease liability, due 2023	2,900			2,900
Total lease liability, due after 2023	9,698			9,698
Total lease liability, total payments	35,063			$ 37,330
Total imputed interest	3,610
Total leases not yet commenced	5,431
Total lease liability	$ 26,022
[1]	Concurrent with the adoption of ASU 2016-02 discussed in Note 2. "Adoption of Accounting Pronouncements," finance lease obligations are now captured in Long-term debt on our Consolidated Balance Sheets.

Leases (Schedule of Future Mini

Leases (Schedule of Future Minimum Rental Payments Prior Year) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Capital leases, due 2019		$ 728
Capital leases, due 2020		141
Capital leases, due 2021		22
Capital leases, due 2022		0
Capital leases, due 2023		0
Capital leases, due after 2023		0
Total capital lease payments		891
Operating leases, due 2019		7,762
Operating leases, due 2020		7,355
Operating leases, due 2021		5,083
Operating leases, due 2022		3,641
Operating leases, due 2023		2,900
Operating leases, due after 2023		9,698
Total operating lease payments		36,439
Total leases due, 2019	$ 6,223	8,490
Total leases, due 2020	7,496	7,496
Total leases, due 2021	5,105	5,105
Total leases, due 2022	3,641	3,641
Total leases, due 2023	2,900	2,900
Total leases, due after 2023	9,698	9,698
Total lease payments	$ 35,063	$ 37,330