Selective Insurance (SIGI) 10-Q 31 Oct 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013
Document Information [Line Items]	'
Document Type	'10-Q
Amendment Flag	'false
Document Period End Date	30-Sep-13
Document Fiscal Year Focus	'2013
Document Fiscal Period Focus	'Q3
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	55,774,851

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
ASSETS	'	'
Fixed maturity securities, held-to-maturity – at carrying value (fair value: $448,529 – 2013; $594,661 – 2012)	$421,962	$554,069
Fixed maturity securities, available-for-sale – at fair value (amortized cost: $3,573,751– 2013 ; $3,130,683 – 2012)	3,633,432	3,296,013
Equity securities, available-for-sale – at fair value (cost: $158,323 – 2013; $132,441 – 2012)	180,506	151,382
Short-term investments (at cost which approximates fair value)	172,087	214,479
Other investments	108,073	114,076
Total investments	4,516,060	4,330,019
Cash	177	210
Interest and dividends due or accrued	36,044	35,984
Premiums receivable, net of allowance for uncollectible accounts of: $4,513 – 2013; $3,906 – 2012	569,214	484,388
Reinsurance recoverables, net	555,579	1,421,109
Prepaid reinsurance premiums	149,182	132,637
Current federal income tax	1,551	2,569
Deferred federal income tax	131,603	119,136
Property and equipment – at cost, net of accumulated depreciation and amortization of: $176,718 – 2013; $169,428 – 2012	50,020	47,131
Deferred policy acquisition costs	177,211	155,523
Goodwill	7,849	7,849
Other assets	71,855	57,661
Total assets	6,266,345	6,794,216
Liabilities And Stockholders' Equity	'	'
Reserve for loss and loss expenses	3,316,291	4,068,941
Unearned premiums	1,111,539	974,706
Notes payable	392,407	307,387
Accrued salaries and benefits	116,682	152,396
Other liabilities	205,217	200,194
Total liabilities	5,142,136	5,703,624
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: 98,957,182 – 2013; 98,194,224 – 2012	197,914	196,388
Additional paid-in capital	284,067	270,654
Retained earnings	1,184,084	1,125,154
Accumulated other comprehensive income	17,083	54,040
Treasury stock - at cost (shares: 43,182,331 – 2013; 43,030,776 – 2012)	-558,939	-555,644
Total stockholders' equity	1,124,209	1,090,592
Commitments and contingencies	'	'
Total liabilities and stockholders' equity	$6,266,345	$6,794,216

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Fixed maturity securities, held-to-maturity, fair value	$448,529	$594,661
Fixed maturity securities, available-for-sale, amortized cost	3,573,751	3,130,683
Equity securities, available-for-sale, cost	158,323	132,441
Premiums receivable, allowance for uncollectible accounts	4,513	3,906
Property and equipment, accumulated depreciation and amortization	$176,718	$169,428
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	98,957,182	98,194,224
Treasury stock, shares	43,182,331	43,030,776

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:	'	'	'	'
Net premiums earned	$437,568	$406,225	$1,284,760	$1,177,266
Net investment income earned	32,457	30,650	99,330	97,284
Net realized gains (losses):	'	'	'	'
Net realized investment gains (losses)	14,111	1,856	25,124	6,907
Other-than-temporary impairments	-680	-921	-3,107	-1,218
Other-than-temporary impairments on fixed maturity securities recognized in other comprehensive income	0	-2,023	-77	-2,241
Total net realized gains (losses)	13,431	-1,088	21,940	3,448
Other income	3,357	1,085	9,677	7,129
Total revenues	486,813	436,872	1,415,707	1,285,127
Expenses:	'	'	'	'
Loss and loss expense incurred	283,317	272,251	832,760	813,060
Policy acquisition costs	145,314	131,849	428,570	391,026
Interest expense	5,570	4,725	16,971	14,148
Other expenses	8,127	7,733	27,852	24,080
Total expenses	442,328	416,558	1,306,153	1,242,314
Income from continuing operations before federal income tax	44,485	20,314	109,554	42,813
Federal income tax expense (benefit):	'	'	'	'
Current	6,367	-5,088	20,041	1,590
Deferred	5,465	7,128	7,433	4,568
Total federal income tax expense	11,832	2,040	27,474	6,158
Net income from continuing operations	32,653	18,274	82,080	36,655
Loss on disposal of discontinued operations, net of tax $(538)	0	0	-997	0
Net income	$32,653	$18,274	$81,083	$36,655
Earnings per share:	'	'	'	'
Basic net income from continuing operations	$0.59	$0.33	$1.48	$0.67
Basic net loss from discontinued operations	$0	$0	($0.02)	$0
Basic net income	$0.59	$0.33	$1.46	$0.67
Diluted net income from continuing operations	$0.57	$0.33	$1.45	$0.66
Diluted net loss from discontinued operations	$0	$0	($0.02)	$0
Diluted net income	$0.57	$0.33	$1.43	$0.66
Dividends to stockholders	$0.13	$0.13	$0.39	$0.39

Consolidated_Statements_of_Inc1

Consolidated Statements of Income Parenthetical (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Tax effect of loss on disposal of discontinued operations	$538

Consolidation_Statements_of_Co

Consolidation Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income	$32,653	$18,274	$81,083	$36,655
Unrealized holding gains (losses) during period	6,383	23,803	-50,576	41,777
Non-credit portion of other-than-temporary impairments recognized in other comprehensive income	0	1,315	50	1,457
HTM Securities	-307	-219	-1,172	-1,236
Realized (gains) losses on available for sale securities	-8,785	674	-16,107	-2,243
Total unrealized (losses) gains on Investment Securities	-2,708	25,579	-67,796	39,932
Amount reclassified into Net Income: Net actuarial loss	513	904	2,222	2,712
Amount reclassified into Net Income: Prior service cost	0	24	6	73
Amount reclassified into Net Income: Curtailment expense	0	0	11	0
Total defined benefit pension and post-retirement plans	513	928	30,839	2,785
Comprehensive income	30,458	44,781	44,126	79,372
Accumulated Defined Benefit Plans Adjustment [Member]	'	'	'	'
Net actuarial gain	0	0	28,600	0
Total defined benefit pension and post-retirement plans	'	'	2,239	'
Accumulated Other-than-Temporary Impairment [Member]	'	'	'	'
Amounts reclassified into Net Income: Non-credit other-than-temporary impairment	1	6	9	177
Other comprehensive (loss) income	'	'	59	'
Accumulated other comprehensive income [Member]	'	'	'	'
Amounts reclassified into Net Income: Non-credit other-than-temporary impairment	'	'	-15,031	'
Other comprehensive (loss) income	($2,195)	$26,507	($36,957)	$42,717

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common stock [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Accumulated other comprehensive income [Member]	Treasury stock [Member]
In Thousands
Beginning of year at Dec. 31, 2011	'	$194,494	$257,370	$1,116,319	$42,294	($552,149)
Dividend reinvestment plan (shares:49,694 – 2013; 68,640 - 2012)	'	137	1,064	'	'	'
Stock purchase and compensation plans (shares: 712,994 - 2013; 698,723 - 2012)	'	1,397	9,093	'	'	'
Net income	36,655	'	'	36,655	'	'
Dividends to stockholders ($0.39 per share - 2013 and 2012)	'	'	'	-21,859	'	'
Other comprehensive (loss) income	'	'	'	'	42,717	'
Acquisition of treasury stock (shares: 151,5555- 2013; 176,513 - 2012)	'	'	'	'	'	-3,154
End of period at Sep. 30, 2012	1,124,378	196,028	267,527	1,131,115	85,011	-555,303
Beginning of year at Jun. 30, 2012	'	'	'	'	'	'
Net income	18,274	'	'	'	'	'
Other comprehensive (loss) income	'	'	'	'	26,507	'
End of period at Sep. 30, 2012	1,124,378	'	'	'	85,011	'
Beginning of year at Dec. 31, 2012	1,090,592	196,388	270,654	1,125,154	54,040	-555,644
Dividend reinvestment plan (shares:49,694 – 2013; 68,640 - 2012)	'	100	1,052	'	'	'
Stock purchase and compensation plans (shares: 712,994 - 2013; 698,723 - 2012)	'	1,426	12,361	'	'	'
Net income	81,083	'	'	81,083	'	'
Dividends to stockholders ($0.39 per share - 2013 and 2012)	'	'	'	-22,153	'	'
Other comprehensive (loss) income	'	'	'	'	-36,957	'
Acquisition of treasury stock (shares: 151,5555- 2013; 176,513 - 2012)	'	'	'	'	'	-3,295
End of period at Sep. 30, 2013	1,124,209	197,914	284,067	1,184,084	17,083	-558,939
Beginning of year at Jun. 30, 2013	'	'	'	'	'	'
Net income	32,653	'	'	'	'	'
Other comprehensive (loss) income	'	'	'	'	-2,195	'
End of period at Sep. 30, 2013	$1,124,209	'	'	'	$17,083	'

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Dividend reinvestment plan, shares	'	'	49,964	68,640
Stock purchase and compensation plans, shares	'	'	712,994	698,723
Dividends to stockholders, per share	$0.13	$0.13	$0.39	$0.39
Acquisition of treasury stock, shares	'	'	151,555	176,513
Preferred stock, par value per share	$0	$0	$0	$0
Preferred stock, shares authorized	5,000,000	5,000,000	5,000,000	5,000,000
Preferred stock, shares issued	0	0	0	0
Series A Preferred Stock [Member]	'	'	'	'
Preferred stock, par value per share	$0	$0	$0	$0
Preferred stock, shares authorized	300,000	300,000	300,000	300,000

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flow (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating Activities	'	'
Net income	$81,083	$36,655
Adjustments to Reconcile Net Income to net Cash Provided by Operating Activities [Abstract]	'	'
Depreciation and amortization	32,861	29,386
Loss on disposal of discontinued operations	997	0
Stock-based compensation expense	7,428	6,263
Undistributed losses of equity method investments	248	1,090
Net realized gains	-21,940	-3,448
Retirement income plan curtailment expense	16	0
Changes in assets and liabilities:	'	'
Increase in reserve for loss and loss expenses, net of reinsurance recoverables	112,876	37,463
Increase in unearned premiums, net of prepaid reinsurance and advance premiums	120,667	119,269
Decrease (increase) in net federal income taxes	8,990	-1,050
Increase in premiums receivable	-84,826	-53,659
Increase in deferred policy acquisition costs	-21,688	-25,744
(Decrease) Increase in interest and dividends due or accrued	-45	721
Increase in accrued salaries and benefits	8,286	5,365
Increase in accrued insurance expenses	6,895	299
Other-net	-13,859	15,144
Net adjustments	156,906	131,099
Net Cash Provided by Operating Activities	237,989	167,754
Investing Activities	'	'
Purchase of fixed maturity securities, available-for-sale	-838,634	-676,408
Purchase of equity securities, available-for-sale	-112,742	-41,004
Purchase of other investments	-7,864	-9,050
Purchase of short-term investments	-1,619,948	-1,231,519
Purchase of subsidiary	0	255
Sale of subsidiary	1,225	600
Sale of fixed maturity securities, available-for-sale	6,851	92,170
Sale of short-term investments	1,662,340	1,263,684
Redemption and maturities of fixed maturity securities, held-to-maturity	87,952	91,665
Redemption and maturities of fixed maturity securities, available-for-sale	413,722	297,980
Sale of equity securities, available-for-sale	109,399	58,749
Distributions from other investments	10,546	13,910
Sale of Other Investments	0	1
Purchase of property and equipment	-10,493	-9,382
Net Cash Used in Investing Activities	-297,646	-148,349
Financing Activities	'	'
Dividends to stockholders	-20,532	-20,188
Acquisition of treasury stock	-3,295	-3,154
Net proceeds from stock purchase and compensation plans	4,305	2,586
Proceeds from issuance of notes payable, net of debt issuance costs	178,435	0
Repayment of notes payable	-100,000	0
Excess tax benefits from share-based payment arrangements	1,479	904
Repayments of capital lease obligations	-768	0
Net cash provided by (used in) financing activities	59,624	-19,852
Net decrease in cash	-33	-447
Cash, beginning of year	210	762
Cash, end of period	$177	$315

Organization

Organization	9 Months Ended
	Sep. 30, 2013
Organization [Abstract]	'
Organization	'
	Organization
	Selective Insurance Group, Inc., through its subsidiaries, (collectively referred to as “we,” “us,” or “our”) offers standard and excess and surplus lines (“E&S”) property and casualty insurance products. Selective Insurance Group, Inc. (referred to as the “Parent”) was incorporated in New Jersey in 1977 and its main offices are located in Branchville, New Jersey. The Parent’s common stock is publicly traded on the NASDAQ Global Select Market under the symbol “SIGI.”
	We classify our business into three operating segments:
	•	Our Standard Insurance Operations segment, which is comprised of both commercial lines ("Commercial Lines") and personal lines ("Personal Lines") business, sells property and casualty insurance products and services in the standard market, including flood insurance through the National Flood Insurance Program's ("NFIP") write-your-own ("WYO") program;
	•	Our E&S Insurance Operations segment, which is comprised of Commercial Lines property and casualty insurance products and services that are unavailable in the standard market due to market conditions or characteristics of the insured that are caused by the insured's claim history or the characteristics of their business; and
	•	Our Investments segment, which invests the premiums collected by our Standard and E&S Insurance Operations, as well as amounts generated through our capital management strategies, which may include the issuance of debt and equity securities.

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2013
Basis of Presentation [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	These interim unaudited consolidated financial statements (“Financial Statements”) include the accounts of the Parent and its subsidiaries, and have been prepared in conformity with: (i) U.S. generally accepted accounting principles (“GAAP”); and (ii) 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.
	Certain amounts in our prior years' Financial Statements and related notes have been reclassified to conform to the 2013 presentation. Such reclassifications had no effect on our net income, stockholders' equity, or cash flows.
	These 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. The Financial Statements cover the third quarters ended September 30, 2013 (“Third Quarter 2013”) and September 30, 2012 (“Third Quarter 2012”) and the nine-month periods ended September 30, 2013 ("Nine Months 2013") and September 30, 2012 ("Nine Months 2012"). The Financial Statements do not include all of the information and disclosures required by GAAP and the SEC for audited annual financial statements. Results of operations for any interim period are not necessarily indicative of results for a full year. Consequently, the 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, 2012 (“2012 Annual Report”).

Adoption_of_Accounting_Pronoun

Adoption of Accounting Pronouncements	9 Months Ended
	Sep. 30, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Adoption Of Accounting Pronouncements	'
	Adoption of Accounting Pronouncements
	In February 2013, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income ("ASU 2013-02"), which adds new disclosure requirements for items reclassified out of Accumulated Other Comprehensive Income ("AOCI"). ASU 2013-02 requires entities to disclose additional information about reclassification adjustments, including: (i) changes in AOCI balances by component; and (ii) significant items reclassified out of AOCI. Prospective application of ASU 2013-02 was effective for fiscal years, and interim periods within those years, beginning after December 15, 2012. We have included the disclosures required by ASU 2013-02 in the notes to our Financial Statements, as required.
	In July 2013, the FASB issued ASU No. 2013-11, Income Taxes, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists (a consensus of the FASB Emerging Issues Task Force) ("ASU 2013-11"). ASU 2013-11 applies to all entities with unrecognized tax benefits that also have tax loss or tax credit carryforwards in the same tax jurisdiction as of the reporting date. An unrecognized tax benefit is the difference between a tax position taken or expected to be taken in a tax return and the benefit that is more likely than not sustainable under examination. Under ASU 2013-11, an entity must net an unrecognized tax benefit, or a portion of an unrecognized tax benefit, against deferred tax assets for a net operating loss ("NOL") carryforward, a similar tax loss, or a tax credit carryforward except when:
	•	An NOL carryforward, a similar tax loss, or a tax credit carryfoward is not available as of the reporting date under the governing tax law to settle taxes that would result from the disallowance of the tax position; or
	•	The entity does not intend to use the deferred tax asset for this purpose.
	If either of these conditions exists, an entity should present an unrecognized tax benefit in the financial statements as a liability and should not net the unrecognized tax benefit with a deferred tax asset.
	ASU 2013-11 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. The adoption of this guidance will not impact our financial condition or results of operation.

Statements_of_Cash_Flow

Statements of Cash Flow	9 Months Ended
	Sep. 30, 2013
Supplemental Cash Flow Information [Abstract]	'
Statements of Cash Flow	'
	Statements of Cash Flow
	Cash paid during Nine Months 2013 and 2012 for interest and federal income taxes was as follows:
		Nine Months ended September 30,
	($ in thousands)	2013		2012
	Cash paid during the period for:
	Interest	$	13,325	11,504
	Federal income tax	17,000		6,300
	At September 30, 2013, included in "Other assets" on the Consolidated Balance Sheets was $7.0 million of cash received from the NFIP, which is restricted to pay flood claims under the WYO program.

Investments

Investments	9 Months Ended
	Sep. 30, 2013
Investments [Abstract]	'
Investments	'
	Investments
	(a) The amortized cost, net unrealized gains and losses, carrying value, unrecognized holding gains and losses, and fair value of held-to-maturity (“HTM”) fixed maturity securities as of September 30, 2013 and December 31, 2012 were as follows:
	September 30, 2013
	($ in thousands)	Amortized Cost			Net		Carrying			Unrecognized		Unrecognized Holding		Fair
					Unrealized Gains		Value			Holding		Losses		Value
					(Losses)					Gains
	Foreign government	$	5,292		151		5,443			122		—		5,565
	Obligations of state and political subdivisions	372,281			4,065		376,346			19,297		—		395,643
	Corporate securities	29,228			(466	)	28,762			3,015		—		31,777
	Asset-backed securities (“ABS”)	5,890			(755	)	5,135			776		—		5,911
	Commercial mortgage-backed securities (“CMBS”)	7,241			(965	)	6,276			3,357		—		9,633
	Total HTM fixed maturity securities	$	419,932		2,030		421,962			26,567		—		448,529
	December 31, 2012
	($ in thousands)	Amortized Cost			Net		Carrying			Unrecognized		Unrecognized Holding		Fair
					Unrealized Gains		Value			Holding		Losses		Value
					(Losses)					Gains
	Foreign government	$	5,292		212		5,504			367		—		5,871
	Obligations of state and political subdivisions	491,180			6,769		497,949			28,996		(23	)	526,922
	Corporate securities	38,285			(812	)	37,473			4,648		—		42,121
	ABS	6,980			(1,052	)	5,928			1,170		—		7,098
	CMBS	8,406			(1,191	)	7,215			5,434		—		12,649
	Total HTM fixed maturity securities	$	550,143		3,926		554,069			40,615		(23	)	594,661
	Unrecognized holding gains and losses of HTM securities are not reflected in the Financial Statements, as they represent fair value fluctuations from the later of: (i) the date a security is designated as HTM; or (ii) the date that an other-than-temporary impairment (“OTTI”) charge is recognized on an HTM security, through the date of the balance sheet. Our HTM securities had an average duration of 2.3 years as of September 30, 2013.
	During Nine Months 2013, 16 securities with a carrying value of $39.6 million and a net unrecognized gain position of $1.4 million, were reclassified from an HTM designation to an available-for-sale (“AFS”) designation due to credit rating downgrades by Moody’s Investors Services ("Moody's") and/or Standard and Poor's Financial Services (“S&P”). These unexpected rating downgrades raised concerns about the issuers’ credit worthiness, which changed our intention to hold these securities to maturity.
	(b) The cost/amortized cost, unrealized gains and losses, and fair value of AFS securities as of September 30, 2013 and December 31, 2012 were as follows:
	September 30, 2013
	($ in thousands)	Cost/			Unrealized		Unrealized			Fair
		Amortized			Gains		Losses			Value
		Cost
	U.S. government and government agencies	$	169,163		11,953		(330	)		180,786
	Foreign government	28,797			996		(84	)		29,709
	Obligations of states and political subdivisions	918,403			27,705		(16,610	)		929,498
	Corporate securities	1,629,698			47,932		(14,479	)		1,663,151
	ABS	150,179			1,063		(476	)		150,766
	CMBS1	152,464			2,747		(3,263	)		151,948
	Residential mortgage-backed	525,047			8,932		(6,405	)		527,574
	securities (“RMBS”)2
	AFS fixed maturity securities	3,573,751			101,328		(41,647	)		3,633,432
	AFS equity securities	158,323			24,061		(1,878	)		180,506
	Total AFS securities	$	3,732,074		125,389		(43,525	)		3,813,938
	December 31, 2012
	($ in thousands)	Cost/			Unrealized		Unrealized			Fair
		Amortized			Gains		Losses			Value
		Cost
	U.S. government and government agencies	$	241,874		17,219		(1	)		259,092
	Foreign government	28,813			1,540		(124	)		30,229
	Obligations of states and political subdivisions	773,953			44,398		(327	)		818,024
	Corporate securities	1,368,954			81,696		(402	)		1,450,248
	ABS	126,330			2,319		(9	)		128,640
	CMBS1	133,763			4,572		(1,216	)		137,119
	RMBS2	456,996			15,961		(296	)		472,661
	AFS fixed maturity securities	3,130,683			167,705		(2,375	)		3,296,013
	AFS equity securities	132,441			19,400		(459	)		151,382
	Total AFS securities	$	3,263,124		187,105		(2,834	)		3,447,395
	1 CMBS includes government guaranteed agency securities with a fair value of $35.5 million at September 30, 2013 and $48.9 million at December 31, 2012.
	2 RMBS includes government guaranteed agency securities with a fair value of $61.4 million at September 30, 2013 and $91.0 million at December 31, 2012.
	Unrealized gains and losses of AFS securities represent fair value fluctuations from the later of: (i) the date a security is designated as AFS; or (ii) the date that an OTTI charge is recognized on an AFS security, through the date of the balance sheet. These unrealized gains and losses are recorded in AOCI on the Consolidated Balance Sheets.
	(c) The following tables summarize, for all securities in a net unrealized/unrecognized loss position at September 30, 2013 and December 31, 2012, the fair value and gross pre-tax net unrealized/unrecognized loss by asset class and by length of time those securities have been in a net loss position:
	September 30, 2013	Less than 12 months					12 months or longer
	($ in thousands)	Fair Value			Unrealized		Fair Value			Unrealized
					Losses1					Losses1
	AFS securities
	U.S. government and government agencies	$	13,173		(327	)	510			(3	)
Foreign government	1,056			(12	)	2,925			(72	)
Obligations of states and political subdivisions	417,866			(16,610	)	—			—
Corporate securities	422,816			(14,200	)	3,837			(279	)
ABS	87,786			(471	)	302			(5	)
CMBS	69,322			(2,771	)	2,030			(492	)
RMBS	202,428			(6,231	)	1,579			(174	)
Total fixed maturity securities	1,214,447			(40,622	)	11,183			(1,025	)
Equity securities	35,275			(1,878	)	—			—
Subtotal	$	1,249,722		(42,500	)	11,183			(1,025	)
	Less than 12 months								12 months or longer
($ in thousands)	Fair			Unrealized		Unrecognized			Fair		Unrealized		Unrecognized
	Value			Losses1		Gains2			Value		Losses1		Gains2
HTM securities
Obligations of states and political subdivisions	$	492		(20	)	19			571		(24	)	17
ABS	—			—		—			2,476		(690	)	642
Subtotal	$	492		(20	)	19			3,047		(714	)	659
Total AFS and HTM	$	1,250,214		(42,520	)	19			14,230		(1,739	)	659
December 31, 2012	Less than 12 months					12 months or longer
($ in thousands)	Fair			Unrealized		Fair Value			Unrealized
	Value			Losses1					Losses1
AFS securities
U.S. government and government agencies	$	518		(1	)	—			—
Foreign government	—			—		2,871			(124	)
Obligations of states and political subdivisions	32,383			(327	)	—			—
Corporate securities	50,880			(402	)	—			—
ABS	9,137			(9	)	—			—
CMBS	7,637			(19	)	11,830			(1,197	)
RMBS	8,710			(59	)	5,035			(237	)
Total fixed maturity securities	109,265			(817	)	19,736			(1,558	)
Equity securities	15,901			(459	)	—			—
Subtotal	$	125,166		(1,276	)	19,736			(1,558	)
	Less than 12 months								12 months or longer
($ in thousands)	Fair			Unrealized		Unrecognized			Fair		Unrealized		Unrecognized
	Value			Losses1		Gains2			Value		Losses1		Gains2
HTM securities
Obligations of states and political subdivisions	$	1,218		(33	)	29			1,108		(47	)	38
ABS	—			—		—			2,860		(840	)	753
Subtotal	1,218			(33	)	29			3,968		(887	)	791
Total AFS and HTM	$	126,384		(1,309	)	29			23,704		(2,445	)	791
1 Gross unrealized losses include non-OTTI unrealized amounts and OTTI losses recognized in AOCI.  In addition, this column includes remaining unrealized gain or loss amounts on securities that were transferred to an HTM designation in the first quarter of 2009 for those securities that are in a net unrealized/unrecognized loss position.
2 Unrecognized gains represent fair value fluctuations from the later of:  (i) the date a security is designated as HTM; or (ii) the date that an OTTI charge is recognized on an HTM security.
As evidenced by the table below, our net unrealized/unrecognized loss positions increased by $40.6 million as of September 30, 2013 compared to December 31, 2012 as follows:
($ in thousands)
September 30, 2013					December 31, 2012
Number of	% of Market/Book	Unrealized/			Number of	% of	Unrealized/
Issues		Unrecognized Loss			Issues	Market/Book	Unrecognized
							Loss
501	80% - 99%	$	43,295		100	80% - 99%	$	2,701
—	60% - 79%	—			1	60% - 79%	233
1	40% - 59%	286			—	40% - 59%	—
—	20% - 39%	—			—	20% - 39%	—
—	0% - 19%	—			—	0% - 19%	—
		$	43,581				$	2,934
We have reviewed the securities in the tables above in accordance with our OTTI policy, as described in Note 2. “Summary of Significant Accounting Policies” in Item 8. “Financial Statements and Supplementary Data.” of our 2012 Annual Report.
At September 30, 2013, we had 502 securities in an aggregate unrealized/unrecognized loss position of $43.6 million, $1.1 million of which have been in a loss position for more than 12 months. At December 31, 2012, we had 101 securities in an aggregate unrealized/unrecognized loss position of $2.9 million, $1.7 million of which had been in a loss position for more than 12 months. During Nine Months 2013, interest rates on the 10-year U.S. Treasury Note rose by 85 basis points. This interest rate movement has negatively impacted our fixed maturity securities portfolio's valuation, thus increasing the number of securities in a loss position and the corresponding dollar amount of unrealized losses. The increase in the unrealized losses does not correspond to any issuer specific credit concerns; however, it does reflect an expected reduction in market value due to higher market interest rates. For a discussion regarding the sensitivity of interest rate movements and the related impacts on the fixed maturity securities portfolio, refer to Item 7A. "Quantitative and Qualitative Disclosures About Market Risk" in our 2012 Annual Report.
We do not intend to sell any securities in an unrealized/unrecognized loss position, nor do we believe we will be required to sell these securities, and therefore we have concluded that they are temporarily impaired as of September 30, 2013. This conclusion reflects our current judgment as to the financial position and future prospects of the entity that issued the investment security and underlying collateral. If our judgment about an individual security changes in the future, we may ultimately record a credit loss after having originally concluded that one did not exist, which could have a material impact on our net income and financial position in future periods.
(d) Fixed maturity securities at September 30, 2013, by contractual maturity, are shown below. Mortgage-backed securities ("MBS") are included in the maturity tables using the estimated average life of each security. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations, with or without call or prepayment penalties.
Listed below are HTM fixed maturity securities at September 30, 2013:
($ in thousands)	Carrying Value			Fair Value
Due in one year or less	$	72,099		74,953
Due after one year through five years	312,318			331,927
Due after five years through 10 years	34,747			38,176
Due after 10 years	2,798			3,473
Total HTM fixed maturity securities	$	421,962		448,529
Listed below are AFS fixed maturity securities at September 30, 2013:
($ in thousands)	Fair Value
Due in one year or less	$	324,743
Due after one year through five years	1,951,770
Due after five years through 10 years	1,329,795
Due after 10 years	27,124
Total AFS fixed maturity securities	$	3,633,432
(e) The following table summarizes our other investment portfolio by strategy and the remaining commitment amount associated with each strategy:
Other Investments	Carrying Value					September 30,
						2013
($ in thousands)	September 30,			December 31,		Remaining Commitment
	2013			2012
Alternative Investments
Secondary private equity	$	25,954		28,032		7,703
Private equity	18,951			18,344		10,502
Energy/power generation	17,049			18,640		7,076
Mezzanine financing	12,921			12,692		18,796
Real estate	12,385			11,751		10,205
Distressed debt	11,911			12,728		2,964
Venture capital	7,018			7,477		400
Total alternative investments	106,189			109,664		57,646
Other securities	1,884			4,412		1,289
Total other investments	$	108,073		114,076		58,935
For a description of our seven alternative investment strategies, as well as information regarding redemption, restrictions, and fund liquidations, refer to Note 5. “Investments” in Item 8. “Financial Statements and Supplementary Data.” of our 2012 Annual Report.
The following table sets forth aggregated summarized financial information for our other investments portfolio that is carried under the equity method of accounting. The last line of the table below reflects our share of the aggregate income, which is the portion included in our Financial Statements. As the majority of these investments report results to us on a quarter lag, the summarized financial statement information for the nine-month periods ended June 30 is as follows:
Income Statement Information	Quarter ended June 30,					Nine Months ended June 30,
($ in millions)	2013			2012		2013			2012
Net investment income	$	97.8		80		352.8			170.1
Realized gains	162.8			19.6		762.5			1,004.90
Net change in unrealized depreciation	104.8			(117.1	)	85.9			(551.1	)
Net income (loss)	$	365.4		(17.5	)	1,201.20			623.9
Selective’s insurance subsidiaries’ other investments income	$	2.6		0.5		10.1			5.5
(f) At September 30, 2013, we had fixed maturity securities, with a carrying value of $61.9 million, that were pledged as collateral for our outstanding borrowing of $58.0 million with the Federal Home Loan Bank of Indianapolis (“FHLBI”).  This outstanding borrowing is included in “Notes payable” on the Consolidated Balance Sheets.  In accordance with the terms of our agreement with the FHLBI, we retain all rights regarding these securities, which are included in the “U.S. government and government agencies,” “RMBS,” and “CMBS” classifications of our AFS fixed maturity securities portfolio.
Also at September 30, 2013, we had fixed maturity securities, with a carrying value of $21.3 million, and short-term investments with a carrying value of $1.7 million, that collateralize reinsurance obligations related to our 2011 acquisition of our E&S book of business. Similar to the FHLBI collateral discussion above, we retain all rights regarding these investments. These fixed maturity securities are included in the "Municipal," "Corporate," "U.S. government and government agencies," "RMBS," and "ABS" classifications of our AFS fixed maturity securities portfolio.
In addition, fixed maturity securities with a carrying value of $27.0 million were on deposit with various state and regulatory agencies to comply with insurance laws. We retain all rights regarding these securities, which are primarily included in the "U.S. government and government agencies" classification of our AFS fixed maturity securities portfolio.
(g) The components of net investment income earned for the periods indicated were as follows:
	Quarter ended September 30,					Nine Months ended September 30,
($ in thousands)	2013			2012		2013			2012
Fixed maturity securities	$	30,569		30,839		90,956			93,948
Equity securities	1,341			1,268		4,422			3,785
Short-term investments	21			36		102			103
Other investments	2,639			497		10,110			5,460
Miscellaneous income	—			41		—			105
Investment expenses	(2,113		)	(2,031	)	(6,260	)		(6,117	)
Net investment income earned	$	32,457		30,650		99,330			97,284
Net investment income before tax increased in both Third Quarter and Nine Months 2013 compared to the same periods last year, primarily due to higher income from our alternative investments. Partially offsetting this increase in Nine Months 2013 is a decrease in fixed maturity securities income due to lower investment yields than in the prior year period.
(h) The following tables summarize OTTI by asset type for the periods indicated:
Third Quarter 2013	Gross			Included in Other		Recognized in
				Comprehensive		Earnings
($ in thousands)				Income (“OCI”)
Equity securities	$	680		—		680
OTTI losses	$	680		—		680
Third Quarter 2012	Gross			Included in OCI		Recognized in Earnings
($ in thousands)
AFS fixed maturity securities
ABS	$	36		—		36
CMBS	(1,504		)	(2,023	)	519
Total AFS fixed maturities	(1,468		)	(2,023	)	555
Equity securities	2,389			—		2,389
OTTI losses	$	921		(2,023	)	2,944
Nine Months 2013	Gross			Included in OCI		Recognized in
($ in thousands)						Earnings
HTM fixed maturity securities:
ABS	$	(44	)	(47	)	3
Total HTM fixed maturity securities	(44		)	(47	)	3
AFS fixed maturity securities:
RMBS	(22		)	(30	)	8
Total AFS fixed maturity securities	(22		)	(30	)	8
Equity securities	1,326			—		1,326
Total AFS securities	1,304			(30	)	1,334
Other investments	1,847			—		1,847
OTTI losses	$	3,107		(77	)	3,184
Nine Months 2012	Gross			Included in OCI		Recognized in
($ in thousands)						Earnings
AFS fixed maturity securities
ABS	$	98		—		98
CMBS	(1,396		)	(2,023	)	627
RMBS	(44		)	(218	)	174
Total AFS fixed maturity securities	(1,342		)	(2,241	)	899
Equity securities	2,560			—		2,560
OTTI losses	$	1,218		(2,241	)	3,459
The majority of the OTTI charges in Nine Months 2013 relate to an investment in a limited liability company within our other investments portfolio that has sustained significant losses for which we do not anticipate recovery. In addition, OTTI charges on our equity portfolio include: (i) $0.7 million recorded in Third Quarter 2013 on securities that we did not believe would recover in the near term; and (ii) $0.6 million recorded within the first half of 2013 primarily related to securities for which we had the intent to sell. For a discussion of our evaluation for OTTI of fixed maturity securities, short-term investments, equity securities and other investments, refer to Note 2. "Summary of Significant Accounting Policies" in Item 8. "Financial Statements and Supplementary Data" of our 2012 Annual Report.
The following tables set forth, for the periods indicated, credit loss impairments on fixed maturity securities for which a portion of the OTTI charge was recognized in OCI, and the corresponding changes in such amounts:
	Quarter ended September 30,
($ in thousands)	2013			2012
Balance, beginning of period	$	7,488		6,775
Addition for the amount related to credit loss for which an OTTI was not previously recognized	—			—
Reductions for securities sold during the period	—			—
Reductions for securities for which the amount previously recognized in OCI was recognized in earnings because of intention or potential requirement to sell before recovery of amortized cost	—			—
Reductions for securities for which the entire amount previously recognized in OCI was recognized in earnings due to a decrease in cash flows expected	—			—
Additional increases to the amount related to credit loss for which an OTTI was previously recognized	—			519
Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	—			—
Balance, end of period	$	7,488		7,294
	Nine Months ended September 30,
($ in thousands)	2013			2012
Balance, beginning of period	$	7,477		6,602
Addition for the amount related to credit loss for which an OTTI was not previously recognized	—			—
Reductions for securities sold during the period	—			—
Reductions for securities for which the amount previously recognized in OCI was recognized in earnings because of intention or potential requirement to sell before recovery of amortized cost	—			—
Reductions for securities for which the entire amount previously recognized in OCI was recognized in earnings due to a decrease in cash flows expected	—			—
Additional increases to the amount related to credit loss for which an OTTI was previously recognized	11			692
Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	—			—
Balance, end of period	$	7,488		7,294
(i) The components of net realized gains, excluding OTTI charges, for the periods indicated were as follows:
	Quarter ended September 30,					Nine Months ended September 30,
($ in thousands)	2013			2012		2013			2012
HTM fixed maturity securities
Gains	$	32		40		35			195
Losses	(37		)	(90	)	(86	)		(196	)
AFS fixed maturity securities
Gains	662			2,168		2,580			2,941
Losses	(31		)	(262	)	(330	)		(379	)
AFS equity securities
Gains	13,801			—		24,272			4,775
Losses	(236		)	—		(407	)		(428	)
Short-term investments
Losses	—			—		—			(2	)
Other Investments
Gains	—			—		—			1
Losses	(80		)	—		(940	)		—
Total other net realized investment gains	14,111			1,856		25,124			6,907
Total OTTI charges recognized in earnings	(680		)	(2,944	)	(3,184	)		(3,459	)
Total net realized gains (losses)	$	13,431		(1,088	)	21,940			3,448
Realized gains and losses on the sale of investments are determined on the basis of the cost of the specific investments sold. Of the $14.1 million and $25.1 million in net realized gains in Third Quarter and Nine Months 2013, $13.5 million and $19.1 million, respectively, were related to the sale of AFS equity securities due to the rebalancing of our high-dividend yield strategy holdings within our equity portfolio. In addition, $4.7 million in net realized gains in Nine Months 2013 related to the sale of a private equity security. Of the $6.9 million of net realized gains in Nine Months 2012, $4.3 million were related to the sale of AFS equity securities due to the rebalancing of our high dividend yield strategy holdings within our equity portfolio.
Proceeds from the sale of AFS securities were $67.2 million in Third Quarter 2013 and $116.3 million in Nine Months 2013, and $55.0 million and $150.9 million in the same periods a year ago.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	The following table presents the carrying amounts and estimated fair values of our financial instruments as of September 30, 2013 and December 31, 2012:
			September 30, 2013					December 31, 2012
	($ in thousands)		Carrying Amount			Fair		Carrying Amount		Fair
						Value				Value
	Financial Assets
	Fixed maturity securities:
	HTM		$	421,962		448,529		554,069		594,661
	AFS		3,633,432			3,633,432		3,296,013		3,296,013
	Equity securities, AFS		180,506			180,506		151,382		151,382
	Short-term investments		172,087			172,087		214,479		214,479
	Receivable for proceeds related to sale of Selective HR Solution (“Selective HR”)		—			—		2,705		2,705
	Financial Liabilities
	Notes payable:
	2.90% borrowings from FHLBI		13,000			13,392		13,000		13,595
	1.25% borrowings from FHLBI		45,000			45,171		45,000		45,590
	7.50% Junior Notes		—			—		100,000		101,480
	6.70% Senior Notes		99,492			100,200		99,475		107,707
	7.25% Senior Notes		49,915			51,858		49,912		52,689
	5.875% Senior Notes		185,000			153,550		—		—
	Total notes payable		$	392,407		364,171		307,387		321,061
	The fair values of our financial assets and liabilities are generated using various valuation techniques and are placed into the fair value hierarchy considering the following: (i) the highest priority is given to quoted prices in active markets for identical assets (Level 1); (ii) the next highest priority is given to quoted prices in markets that are not active or inputs that are observable either directly or indirectly, including quoted prices for similar assets in markets that are not active and other inputs that can be derived principally from, or corroborated by, observable market data for substantially the full term of the assets (Level 2); and (iii) the lowest priority is given to unobservable inputs supported by little or no market activity and that reflect our assumptions about the exit price, including assumptions that market participants would use in pricing the asset (Level 3). An asset or liability's classification within the fair value hierarchy is based on the lowest level of significant input to its valuation. Transfers between levels in the fair value hierarchy are recognized at the end of the reporting period.
	For a discussion of the techniques used to value the majority of our financial assets and liabilities, refer to Note 2. "Summary of Significant Accounting Policies" in Item 8. "Financial Statements and Supplementary Data." of our 2012 Annual Report. The 5.875% Senior Notes were valued based on a quoted market price (Level 1). The fair value at September 30, 2013 of the 6.70% Senior Notes due November 1, 2035 is based on a matrix pricing model prepared by an external pricing service due to the availability and nature of the pricing at the valuation date (Level 2).
	The following tables provide quantitative disclosures of our financial assets that were measured at fair value at September 30, 2013 and December 31, 2012:
	September 30, 2013					Fair Value Measurements Using
	($ in thousands)		Assets			Quoted Prices in		Significant Other		Significant Unobservable
			Measured at			Active Markets for		Observable		Inputs
			Fair Value			Identical Assets/		Inputs		(Level 3)
			at 9/30/13			Liabilities (Level 1)1		(Level 2)1
	Description
	Measured on a recurring basis:
	AFS:
	U.S. government and government agencies		$	180,786		50,871		129,915		—
	Foreign government		29,709			—		29,709		—
	Obligations of states and political subdivisions		929,498			—		929,498		—
	Corporate securities		1,663,151			—		1,663,151		—
	ABS		150,766			—		144,804		5,962
	CMBS		151,948			—		150,339		1,609
	RMBS		527,574			—		527,574		—
	Total AFS fixed maturity securities		3,633,432			50,871		3,574,990		7,571
	Equity securities		180,506			177,606		—		2,900
	Short-term investments		172,087			172,087		—		—
	Total assets		$	3,986,025		400,564		3,574,990		10,471
	1	There were no transfers of securities between Level 1 and Level 2.
	December 31, 2012					Fair Value Measurements Using
	($ in thousands)		Assets			Quoted Prices in		Significant		Significant Unobservable
			Measured at			Active Markets for		Other Observable		Inputs
			Fair Value			Identical Assets/Liabilities		Inputs		(Level 3)
			at 12/31/12			(Level 1)1		(Level 2)1
	Description
	Measured on a recurring basis:
	AFS:
	U.S. government and government agencies		$	259,092		115,861		123,442		19,789
	Foreign government		30,229			—		30,229		—
	Obligations of states and political subdivisions		818,024			—		818,024		—
	Corporate securities		1,450,247			—		1,447,301		2,946
	ABS		128,640			—		122,572		6,068
	CMBS		137,119			—		129,957		7,162
	RMBS		472,662			—		472,662		—
	Total AFS fixed maturity securities		3,296,013			115,861		3,144,187		35,965
	Equity securities		151,382			147,775		—		3,607
	Short-term investments		214,479			214,479		—		—
	Receivable for proceeds related to sale of Selective HR		2,705			—		—		2,705
Total assets		$	3,664,579		478,115		3,144,187		42,277
1	There were no transfers of securities between Level 1 and Level 2.
The following tables provide a summary of the changes in the fair value of securities measured using Level 3 inputs and related quantitative information for the periods ended September 30, 2013 and December 31, 2012:
September 30, 2013
($ in thousands)		Government			Corporate		ABS		CMBS		Equity		Receivable for		Total
													Proceeds
													Related to Sale
													of Selective HR
Fair value, December 31, 2012		$	19,789		2,946		6,068		7,162		3,607		2,705		42,277
Total net (losses) gains for the period included in:
OCI1		(537		)	(7	)	(106	)	681		3,935		—		3,966
Net income2,3		(76		)	—		—		354		—		(1,480	)	(1,202	)
Purchases		—			—		—		—		—		—		—
Sales		—			—		—		—		—		—		—
Issuances		—			—		—		—		—		—		—
Settlements		(1,847		)	(168	)	—		(1,603	)	—		(225	)	(3,843	)
Transfers into Level 3		—			—		—		—		—		—		—
Transfers out of Level 3		(17,329		)	(2,771	)	—		(4,985	)	(4,642	)	(1,000	)	(30,727	)
Fair value, September 30, 2013		$	—		—		5,962		1,609		2,900		—		10,471
1 Amounts are reported in “Unrealized holding gains (losses) arising during period” on the Unaudited Consolidated Statements of Comprehensive Income.
2 Amounts are reported in “Net realized gains (losses)” for realized gains and “Net investment income earned” for amortization of securities on the Unaudited Consolidated Statements of Income.
3 For the receivable related to the sale of Selective HR, amounts in “Loss on disposal of discontinued operations, net of tax” relate to an impairment charge and amounts in “Other income” relate to interest accretion on the Unaudited Consolidated Statements of Income.
31-Dec-12
($ in thousands)		Government			Corporate		ABS		CMBS		Equity		Receivable for		Total
													Proceeds
													Related to Sale
													of Selective HR
Fair value, December 31, 2011		$	21,741		2,603		—		354		—		3,212		27,910
Total net (losses) gains for the period included in:
OCI1		(22		)	185		68		858		—		—		1,089
Net income2,3		(193		)	—		—		(51	)	—		244		—
Purchases		—			—		7,300		5,611		—		—		12,911
Sales		—			—		—		—		—		—		—
Issuances		—			—		—		—		—		—		—
Settlements		(1,737		)	(630	)	—		(624	)	—		(751	)	(3,742	)
Transfers into Level 3		—			788		—		8,247		3,607		—		12,642
Transfers out of Level 3		—			—		(1,300	)	(7,233	)	—		—		(8,533	)
Fair value, December 31, 2012		$	19,789		2,946		6,068		7,162		3,607		2,705		42,277
1 Amounts are reported in “Unrealized holding gains arising during period” on the Consolidated Statements of Comprehensive Income in our 2012 Annual Report.
2 Amounts are reported in “Net realized gains (losses)” for realized gains and losses and “Net investment income earned” for amortization for the CMBS securities on the Consolidated Statements of Income in our 2012 Annual Report.
3 Amounts are reported in “Other income” for the receivable related to the sale of Selective HR on the Consolidated Statements of Income in our 2012 Annual Report and are related to interest accretion on the receivable.
As discussed in Note 2. "Summary of Significant Accounting Policies," in Item 8. "Financial Statements and Supplementary Data." in our 2012 Annual Report, the fair value of our Level 3 fixed maturity securities is typically obtained through non-binding broker quotes based on unobservable inputs, which we review for reasonableness. At September 30, 2013 and December 31, 2012, fixed maturity securities with aggregate fair values of $7.6 million and $36.0 million, respectively, were measured using Level 3 inputs primarily due to the availability and nature of the pricing used at the valuation dates.
During Nine Months 2013, fixed maturity securities with an aggregate fair value of $25.1 million were transferred out of Level 3 due to the availability of Level 2 pricing that was not available previously.
In 2012, fixed maturity securities with a fair value of $9.0 million were transferred into Level 3 during the year. These transfers were primarily related to securities that had been previously priced using Level 2 inputs, but due to the availability and nature of the pricing used at the valuation dates, were priced using Level 3 inputs at December 31, 2012. In addition, certain of these transfers related to securities that had previously been classified as HTM, and therefore not measured at fair value, for which available pricing at December 31, 2012 used Level 3 inputs. Securities with a fair value of $8.5 million were transferred out of Level 3 due to the availability of Level 2 pricing at December 31, 2012 that was not available previously.
Equity securities with fair values of $2.9 million and $3.6 million were measured using Level 3 inputs at September 30, 2013 and December 31, 2012, respectively. During 2012, two non-publicly traded equity securities were transferred into Level 3 due to the nature of the quotes used at the valuation date. One of these securities was transferred out of Level 3 and into Level 2 at March 31, 2013, as the pricing as of that date was based on a quoted price in an inactive market. This security was subsequently sold in the second quarter of 2013 for an amount that approximated the March 31, 2013 value. At each reporting date, we review the fair value of the remaining Level 3 security for reasonableness.
At December 31, 2012, the receivable related to the sale of Selective HR was contingent on the purchaser's ability to retain business subsequent to the sale. At that time, the fair value of this receivable was measured using unobservable inputs, the most significant of which was our assumption regarding the retention of business. In the first quarter of 2013, we reached an agreement with the purchaser to settle this receivable for an aggregate of $1.0 million, which was paid in two installments. As a result, the receivable was transferred out of Level 3. See Note 12. "Discontinued Operations" of this Form 10-Q for a discussion of the impairment charge that was recorded on this receivable in the first quarter of 2013.
The following tables provide quantitative information regarding our financial assets and liabilities that were disclosed at fair value at September 30, 2013 and December 31, 2012:
September 30, 2013					Fair Value Measurements Using
($ in thousands)		Assets/			Quoted Prices in		Significant Other		Significant
		Liabilities			Active Markets for		Observable		Unobservable
		Disclosed at			Identical Assets/		Inputs		Inputs
		Fair Value at 9/30/2013			Liabilities		(Level 2)		(Level 3)
					(Level 1)
Financial Assets
HTM:
Foreign government		$	5,565		—		5,565		—
Obligations of states and political subdivisions		395,643			—		395,643		—
Corporate securities		31,777			—		31,777		—
ABS		5,911			—		4,854		1,057
CMBS		9,633			—		9,633		—
Total HTM fixed maturity securities		$	448,529		—		447,472		1,057
Financial Liabilities
Notes payable:
2.90% borrowings from FHLBI		$	13,392		—		13,392		—
1.25% borrowings from FHLBI		45,171			—		45,171		—
6.70% Senior Notes		100,200			—		100,200		—
7.25% Senior Notes		51,858			—		51,858		—
5.875% Senior Notes		153,550			153,550		—		—
Total notes payable		$	364,171		153,550		210,621		—
December 31, 2012					Fair Value Measurements Using
($ in thousands)		Assets/			Quoted Prices in		Significant Other		Significant
		Liabilities			Active Markets for		Observable		Unobservable
		Disclosed at			Identical Assets/		Inputs		Inputs
		Fair Value at 12/31/2012			Liabilities		(Level 2)		(Level 3)
					(Level 1)
Financial Assets
HTM:
Foreign government		$	5,871		—		5,871		—
Obligations of states and political subdivisions		526,922			—		526,922		—
Corporate securities		42,121			—		37,289		4,832
ABS		7,097			—		5,698		1,399
CMBS		12,650			—		12,650		—
Total HTM fixed maturity securities		$	594,661		—		588,430		6,231
Financial Liabilities
Notes payable:
2.90% borrowings from FHLBI		$	13,595		—		13,595		—
1.25% borrowings from FHLBI		45,590			—		45,590		—
7.50% Junior Notes		101,480			101,480		—		—
6.70% Senior Notes		107,707			107,707		—		—
7.25% Senior Notes		52,689			—		52,689		—
Total notes payable		$	321,061		209,187		111,874		—

Reinsurance

Reinsurance	9 Months Ended
	Sep. 30, 2013
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 2012 Annual Report.
		Quarter ended September 30,					Nine Months ended September 30,
	($ in thousands)	2013			2012		2013		2012
	Premiums written:
	Direct	$	570,849		520,943		1,650,855		1,504,429
	Assumed	22,053			17,976		34,913		44,712
	Ceded	(100,154		)	(88,401	)	(280,719	)	(252,888	)
	Net	$	492,748		450,518		1,405,049		1,296,253
	Premiums earned:
	Direct	$	518,307		474,055		1,516,454		1,389,373
	Assumed	11,066			18,595		32,480		49,683
	Ceded	(91,805		)	(86,425	)	(264,174	)	(261,790	)
	Net	$	437,568		406,225		1,284,760		1,177,266
	Loss and loss expense incurred:
	Direct	$	350,648		327,883		1,055,248		881,537
	Assumed	7,264			13,970		22,758		35,039
	Ceded	(74,595		)	(69,602	)	(245,246	)	(103,516	)
	Net	$	283,317		272,251		832,760		813,060
	The growth in direct premium written ("DPW") for our ten insurance subsidiaries ("Insurance Subsidiaries") in both Third Quarter and Nine Months 2013 compared to Third Quarter and Nine Months 2012 reflects: (i) pure price increases that we have achieved in our Standard Insurance Operations; and (ii) strong retention in our Standard Insurance Operations.
	Direct premiums earned increases in Third Quarter and Nine Months 2013 were consistent with the fluctuation in DPW for the twelve-month period ended September 30, 2013 as compared to the twelve-month period ended September 30, 2012.
	Assumed premiums written for Nine Months 2013 decreased compared to the same period last year as E&S business, which was previously written through a reinsurance fronting agreement, is now written directly by our Insurance Subsidiaries. Decreases in assumed premiums earned in Third Quarter and Nine Months 2013 compared to Third Quarter and Nine Months 2012 were driven by the E&S premiums.
	Direct loss and loss expense incurred in Nine Months 2013 included an increase of approximately $128 million related to flood losses covered under the NFIP for Hurricane Sandy, which occurred in October 2012. Total estimated gross flood losses covered by the Insurance Subsidiaries' WYO policies under the NFIP program for this storm were $1,179 million at September 30, 2013 and $1,052 million at December 31, 2012, of which approximately $1,148 million was paid through September 30, 2013.
	As all flood losses are fully ceded under the NFIP, the increase in direct loss and loss expense drives the corresponding increase in our ceded losses.
	The ceded premiums and losses related to our participation in the NFIP, under which 100% of our flood premiums, losses, and loss expenses are ceded to the NFIP, are as follows:
	NFIP	Quarter ended September 30,					Nine Months ended September 30,
	($ in thousands)	2013			2012		2013		2012
	Ceded premiums written	$	(64,196	)	(58,923	)	(183,364	)	(171,172	)
	Ceded premiums earned	(57,920		)	(53,222	)	(169,697	)	(157,895	)
	Ceded loss and loss expense incurred	(34,879		)	(32,702	)	(162,780	)	(24,534	)

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment Information	'
	Segment Information
	The results of our three operating segments are used by senior management to manage our operations. These segments are evaluated based on the following:
	•	Our Standard Insurance Operations segment and our E&S Insurance Operations segment are evaluated based on statutory underwriting results (net premiums earned, incurred loss and loss expenses, policyholders dividends, policy acquisition costs, and other underwriting expenses), and statutory combined ratios; and
	•	Our Investments segment is evaluated based on net investment income and net realized gains and losses.
	In computing the results of each segment, we do not make adjustments for interest expense, net general corporate expenses, or federal income taxes. We do not maintain separate investment portfolios for the segments and therefore, do not allocate assets to the segments.
	The following summaries present revenues from continuing operations (net investment income and net realized gains on investments in the case of the Investments segment) and pre-tax income from continuing operations for the individual segments:
	Revenue by Segment		Quarter ended September 30,					Nine Months ended September 30,
	($ in thousands)		2013			2012		2013		2012
	Standard Insurance Operations:
	Net premiums earned:
	Commercial automobile		$	79,138		72,758		230,191		214,782
	Workers compensation		66,510			65,592		197,449		198,064
	General liability		100,925			93,763		298,394		276,538
	Commercial property		57,004			52,197		165,356		151,945
	Businessowners’ policies		19,629			17,749		56,794		51,872
	Bonds		4,705			4,713		14,244		14,076
	Other		3,051			2,921		9,036		9,202
	Total standard Commercial Lines		330,962			309,693		971,464		916,479
	Personal automobile		38,513			38,295		115,432		113,648
	Homeowners		32,374			29,919		95,211		86,685
	Other		3,827			3,591		10,655		10,037
	Total standard Personal Lines		74,714			71,805		221,298		210,370
	Total Standard Insurance Operations net premiums earned		405,676			381,498		1,192,762		1,126,849
	Miscellaneous income		3,342			1,009		9,590		6,904
	Total Standard Insurance Operations revenue		409,018			382,507		1,202,352		1,133,753
	E&S Insurance Operations:
	Net premiums earned		31,892			24,727		91,998		50,417
	Investments:
	Net investment income		32,457			30,650		99,330		97,284
	Net realized investment gains (losses)		13,431			(1,088	)	21,940		3,448
	Total investment revenues		45,888			29,562		121,270		100,732
	Total all segments		486,798			436,796		1,415,620		1,284,902
	Other income		15			76		87		225
	Total revenues from continuing operations		$	486,813		436,872		1,415,707		1,285,127
	Income from Continuing Operations before Federal Income Tax		Quarter ended September 30,					Nine Months ended September 30,
	($ in thousands)		2013			2012		2013		2012
	Standard Insurance Operations:
	Commercial Lines underwriting gain (loss)		$	8,776		(651	)	24,621		(14,666	)
	Personal Lines underwriting gain		1,362			7,220		4,360		2,903
	Total Standard Insurance Operations underwriting gain (loss), before federal income tax		10,138			6,569		28,981		(11,763	)
	GAAP combined ratio		97.5		%	98.3		97.6		101
	Statutory combined ratio		96		%	96.9		96.6		100.1
	E&S Insurance Operations:
	Underwriting gain (loss)		13			(5,708	)	(2,186	)	(15,701	)
	GAAP combined ratio		100		%	123.1		102.4		131.1
	Statutory combined ratio		100.5		%	121.6		101.9		120.3
	Investments:
	Net investment income		32,457			30,650		99,330		97,284
	Net realized investment gains (losses)		13,431			(1,088	)	21,940		3,448
	Total investment income, before federal income tax		45,888			29,562		121,270		100,732
	Total all segments		56,039			30,423		148,065		73,268
	Interest expense		(5,570		)	(4,725	)	(16,971	)	(14,148	)
	General corporate and other expenses		(5,984		)	(5,384	)	(21,540	)	(16,307	)
	Income from continuing operations before federal income tax		$	44,485		20,314		109,554		42,813

Indebtedness

Indebtedness	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Indebtedness	'
	Indebtedness
	(a) Notes Payable
	In the first quarter of 2013, we issued $185 million of 5.875% Senior Notes due 2043. The Senior Notes pay interest on February 15, May 15, August 15, and November 15 of each year, beginning on May 15, 2013, and at maturity. The notes are callable by us on or after February 8, 2018, at a price equal to 100% of their principal outstanding amount, plus accrued and unpaid interest to, but excluding, the date of redemption. A portion of the proceeds from this debt issuance was used to fully redeem the $100 million aggregate principal amount of our 7.5% Junior Subordinated Notes due 2066, which had an associated $3.3 million pre-tax write-off for the remaining capitalized debt issuance costs on these notes. Of the remaining net proceeds, $57.1 million was used to make capital contributions to the Insurance Subsidiaries, while the balance was used for general corporate purposes.
	(b) Short-Term Debt
	Our line of credit ("Line of Credit") with Wells Fargo Bank, National Association, as administrative agent, and Branch Banking and Trust Company (BB&T), was renewed effective September 26, 2013 with a borrowing capacity of $30 million, which can be increased to $50 million with the approval of both lending partners. The Line of Credit provides the Parent with an additional source of short-term liquidity. The interest rate on our Line of Credit varies and is based on, among other factors, the Parent’s debt ratings. The Line of Credit expires on September 26, 2017. There have been no balances outstanding under this Line of Credit or the previous credit facility at September 30, 2013 or at any time during Nine Months 2013.
	The Line of Credit agreement contains representations, warranties, and covenants that are customary for credit facilities of this type, including, without limitation, financial covenants under which we are obligated to maintain a minimum consolidated net worth, minimum combined statutory surplus, and maximum ratio of consolidated debt to total capitalization, as well as covenants limiting our ability to: (i) merge or liquidate; (ii) incur debt or liens; (iii) dispose of assets; (iv) make certain investments and acquisitions; and (v) engage in transactions with affiliates. The Line of Credit permits collateralized borrowings by the two Insurance Subsidiaries domiciled in Indiana ("Indiana Subsidiaries") from the FHLBI so long as the aggregate amount borrowed does not exceed 10% of the respective Indiana Subsidiary’s admitted assets from the preceding calendar year.
	The table below outlines information regarding certain of the covenants in the Line of Credit:
		Required as of	Actual as of
		30-Sep-13	30-Sep-13
	Consolidated net worth	$785 million	$1.1 billion
	Statutory surplus	Not less than $750 million	$1.2 billion
	Debt-to-capitalization ratio1	Not to exceed 35%	26.00%
	A.M. Best financial strength rating	Minimum of A-	A
	1Calculated in accordance with the Line of Credit agreement.
	For additional information related to all our outstanding debt, refer to Note 10. "Indebtedness" in Item 8. "Financial Statements and Supplementary Data." of our 2012 Annual Report.

Retirement_Plans

Retirement Plans	9 Months Ended
	Sep. 30, 2013
Compensation and Retirement Disclosure [Abstract]	'
Retirement Plans	'
	Retirement Plans
	The Retirement Income Plan for Selective Insurance Company of America and the Supplemental Excess Retirement Plan (jointly referred to as the "Retirement Income Plan") were amended in the first quarter of 2013 to curtail the accrual of additional benefits for all employees eligible to participate in the plans after March 31, 2016. The curtailment of the plans resulted in a net actuarial gain recognized in OCI of $44.0 million on a pre-tax basis.
	As a result of the curtailment, the Retirement Income Plan was re-measured as of March 31, 2013. When determining the most appropriate discount rate to be used in the valuation, we considered, among other factors, our expected payout patterns of the Retirement Income Plan's obligations, as well as our investment strategy. We ultimately selected the rate that we believe best represents our estimate of the inherent interest rate at which the Retirement Income Plan's liabilities can be effectively settled. The expected rate of return on plan assets at March 31, 2013 remained at 7.40%, consistent with our December 31, 2012 assumption. For re-measurement, we determined that the most appropriate discount rate was 4.66%, up slightly from 4.42% determined as of December 31, 2012.
	Eligible employees impacted by the curtailment of the Retirement Income Plan began receiving, on April 5, 2013, an enhanced company contribution to the Selective Insurance Retirement Savings Plan of 4% of base salary, which is the enhanced company contribution currently provided to all employees not eligible to participate in the Retirement Income Plan.
	The funded status of the Retirement Income Plan recognized in the Consolidated Balance Sheets as of September 30, 2013, the valuation of which was updated as of March 31, 2013 as a result of the first quarter curtailment discussed above, and December 31, 2012, was as follows:
		Retirement Income Plan
	($ in thousands)	30-Sep-13				31-Dec-12
	Change in Benefit Obligation:
	Benefit obligation, beginning of year	$	302,647			254,009
	Service cost	2,449				8,091
	Interest cost	3,303				12,981
	Actuarial (gain) losses	(11,485		)		33,596
	Benefits paid	(1,598		)		(6,030	)
	Impact of curtailment	(29,603		)		—
	Benefit obligation, end of period	$	265,713			302,647
	Change in Fair Value of Assets:
	Fair value of assets, beginning of year	$	207,150			182,614
	Actual return on plan assets, net of expenses	6,760				21,896
	Contribution by employer to funded plans	2,650				8,550
	Contribution by employer to unfunded plans	30				120
	Benefits paid	(1,598		)		(6,030	)
	Fair value of assets, end of period	$	214,992			207,150
	Funded status	$	(50,721	)		(95,497	)
	Amount Recognized in Consolidated Balance Sheet:
	Liabilities	$	(50,721	)		(95,497	)
	Net pension liability, end of period	$	(50,721	)		(95,497	)
	Amount Recognized in AOCI:
	Prior service cost	$	—			26
	Net actuarial loss	57,543				103,365
	Total	$	57,543			103,391
	Other Information:
	Accumulated benefit obligation	$	257,412			265,899
	Weighted-Average Liability Assumptions:
	Discount Rate	4.66	%		4.42
	Rate of compensation increase	4	%		4
	The following table shows the cost of the Retirement Income Plan and the life insurance benefit ("Retirement Life Plan") for the quarterly and nine month periods ended September 30, 2013 and September 30, 2012:
		Retirement Income Plan							Retirement Life Plan
		Quarter ended September 30,							Quarter ended September 30,
	($ in thousands)	2013				2012			2013		2012
	Components of Net Periodic Benefit Cost and Other Amounts Recognized in OCI:
	Net Periodic Benefit Cost:
	Service cost	$	1,857			2,154			—		—
	Interest cost	3,053				3,230			69		73
	Expected return on plan assets	(3,986		)		(3,547	)		—		—
	Amortization of unrecognized prior service cost	—				38			—		—
	Amortization of unrecognized net actuarial loss	772				1,383			18		8
	Total net periodic cost	$	1,696			3,258			87		81
	Other Changes in Plan Assets and Benefit Obligations Recognized in OCI:
	Reversal of amortization of net actuarial loss	$	(772	)		(1,383	)		(18	)	(8	)
	Reversal of amortization of prior service cost	—				(38	)		—		—
	Total recognized in OCI	$	(772	)		(1,421	)		(18	)	(8	)
	Total recognized in net periodic benefit cost and OCI	$	924			1,837			69		73
		Retirement Income Plan							Retirement Life Plan
		Nine Months ended September 30,							Nine Months ended September 30,
	($ in thousands)	2013				2012			2013		2012
	Components of Net Periodic Benefit Cost and Other Amounts Recognized in OCI:
	Net Periodic Benefit Cost:
	Service cost	$	6,163			6,462			—		—
	Interest cost	9,407				9,690			208		221
	Expected return on plan assets	(11,819		)		(10,641	)		—		—
	Amortization of unrecognized prior service cost	10				113			—		—
	Amortization of unrecognized net actuarial loss	3,366				4,149			53		23
	Curtailment expense	16				—			—		—
Total net periodic cost	$	7,143			9,773			261		244
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI:
Net actuarial gain due to curtailment	$	(44,000	)		—			—		—
Reversal of amortization of net actuarial loss	(3,366		)		(4,149	)		(53	)	(23	)
Reversal of amortization of prior service cost	(10		)		(113	)		—		—
Curtailment expense	(16		)		—			—		—
Total recognized in OCI	$	(47,392	)		(4,262	)		(53	)	(23	)
Total recognized in net periodic benefit cost and OCI	$	(40,249	)		5,511			208		221
The amortization of prior service cost related to the Retirement Income Plan is determined using a straight-line amortization of the cost over the average remaining service period of employees expected to receive benefits under the Retirement Income Plan.
The estimated net actuarial loss for the Retirement Income Plan that will be amortized from AOCI into net periodic benefit cost during the 2013 fiscal year is $4.1 million.
	Retirement Income Plan					Retirement Life Plan
	Nine Months ended September 30,					Nine Months ended September 30,
	2013			2012		2013			2012
Weighted-Average Expense Assumptions:
Discount rate	4.66	%		5.16		4.42	%		5.16
Expected return on plan assets	7.4			7.75		—			—
Rate of compensation increase	4			4		—			—
The following table presents future benefit payments expected under the Retirement Income Plan:
($ in thousands)	Retirement Income Plan
Benefits Expected to be Paid in Future Years
Fiscal Years:
2013	$	7,586
2014	8,384
2015	9,148
2016	9,942
2017	10,810
2018-2022	67,447
For additional information regarding our retirement plans, refer to Note 15. "Retirement Plans" included in Item 8. "Financial Statements and Supplementary Data." of our 2012 Annual Report.

Comprehensive_Income

Comprehensive Income	9 Months Ended
	Sep. 30, 2013
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 Third Quarter and Nine Months 2013 and 2012 are as follows:
	Third Quarter 2013
	($ in thousands)		Gross				Tax		Net
	Net income		$	44,485			11,832		32,653
	Components of OCI:
	Unrealized losses on investment securities:
	Unrealized gains during the period		9,820				3,437		6,383
	Amounts reclassified into net income:
	HTM securities		(472		)		(165	)	(307	)
	Non-credit OTTI		1				—		1
	Realized gains on AFS securities		(13,516		)		(4,731	)	(8,785	)
	Net unrealized losses		(4,167		)		(1,459	)	(2,708	)
	Defined benefit pension and post-retirement plans:
	Amounts reclassified into net income:
	Net actuarial loss		790				277		513
	Defined benefit pension and post-retirement plans		790				277		513
	Other comprehensive loss		(3,377		)		(1,182	)	(2,195	)
	Comprehensive income		$	41,108			10,650		30,458
	Third Quarter 2012
	($ in thousands)		Gross				Tax		Net
	Net income		$	20,314			2,040		18,274
	Components of OCI:
	Unrealized gains on investment securities:
	Unrealized holding gains during the period		36,620				12,817		23,803
	Non-credit OTTI recognized in OCI		2,023				708		1,315
	Amounts reclassified into net income:
	HTM securities		(336		)		(117	)	(219	)
	Non-credit OTTI		9				3		6
	Realized losses on AFS securities		1,037				363		674
	Net unrealized gains		39,353				13,774		25,579
	Defined benefit pension and post-retirement plans:
	Amounts reclassified into net income:
	Net actuarial loss		1,391				487		904
	Prior service cost		38				14		24
	Defined benefit pension and post-retirement plans		1,429				501		928
	Other comprehensive income		40,782				14,275		26,507
	Comprehensive income		$	61,096			16,315		44,781
	Nine Months 2013
	($ in thousands)		Gross				Tax		Net
	Net income		$	108,019			26,936		81,083
	Components of OCI:
	Unrealized losses on investment securities:
	Unrealized holding losses during the period		(77,810		)		(27,234	)	(50,576	)
	Non-credit OTTI recognized in OCI		77				27		50
	Amounts reclassified into net income:
	HTM securities		(1,803		)		(631	)	(1,172	)
	Non-credit OTTI		14				5		9
	Realized gains on AFS securities		(24,780		)		(8,673	)	(16,107	)
	Net unrealized losses		(104,302		)		(36,506	)	(67,796	)
	Defined benefit pension and post-retirement plans:
	Net actuarial gain		44,000				15,400		28,600
	Amounts reclassified into net income:
	Net actuarial loss		3,419				1,197		2,222
	Prior service cost		10				4		6
	Curtailment expense		16				5		11
	Defined benefit pension and post-retirement plans		47,445				16,606		30,839
	Other comprehensive loss		(56,857		)		(19,900	)	(36,957	)
	Comprehensive income		$	51,162			7,036		44,126
	Nine Months 2012
	($ in thousands)		Gross				Tax		Net
	Net income		$	42,813			6,158		36,655
	Components of OCI:
Unrealized gains on investment securities:
Unrealized holding gains during the period		64,273				22,496		41,777
Non-credit OTTI recognized in OCI		2,241				784		1,457
Amounts reclassified into net income:
HTM securities		(1,901		)		(665	)	(1,236	)
Non-credit OTTI		272				95		177
Realized gains on AFS securities		(3,451		)		(1,208	)	(2,243	)
Net unrealized gains		61,434				21,502		39,932
Defined benefit pension and post-retirement plans:
Amounts reclassified into net income:
Net actuarial loss		4,172				1,460		2,712
Prior service cost		113				40		73
Defined benefit pension and post-retirement plans		4,285				1,500		2,785
Other comprehensive income		65,719				23,002		42,717
Comprehensive income		$	108,532			29,160		79,372
The balances of, and changes in, each component of AOCI (net of taxes) as of September 30, 2013 are as follows:
September 30, 2013		Net Unrealized (Loss) Gain on Investment Securities
($ in thousands)		OTTI				HTM		All		Investments		Defined Benefit		Total AOCI
		Related				Related		Other		Subtotal		Pension and Post-Retirement Plans
Balance, December 31, 2012		$	(1,658	)		2,594		121,391		122,327		(68,287	)	54,040
OCI before reclassifications		50				(103	)	(50,473	)	(50,526	)	28,600		(21,926	)
Amounts reclassified from AOCI		9				(1,172	)	(16,107	)	(17,270	)	2,239		(15,031	)
Net current period OCI		59				(1,275	)	(66,580	)	(67,796	)	30,839		(36,957	)
Balance, September 30, 2013		$	(1,599	)		1,319		54,811		54,531		(37,448	)	17,083
The reclassifications out of AOCI for Third Quarter and Nine Months 2013 are as follows:
	Amount Reclassified from AOCI							Affected Line Item in the Unaudited Consolidated Statement of Income
($ in thousands)	Quarter ended September 30, 2013				Nine Months ended September 30, 2013
OTTI related
Amortization of non-credit OTTI losses on HTM securities
	$	1			14			Net investment income earned
	1				14			Income (loss) from continuing operations, before federal income tax
	—				(5		)	Total federal income tax expense (benefit)
	1				9			Net income
HTM related
Unrealized gains and losses on HTM disposals	(19		)		(170		)	Net realized investment gains
Amortization of net unrealized gains on HTM securities	(453		)		(1,633		)	Net investment income earned
	(472		)		(1,803		)	Income (loss) from continuing operations, before federal income tax
	165				631			Total federal income tax expense (benefit)
	(307		)		(1,172		)	Net income
Realized gains and losses on AFS
Realized gains and losses on AFS disposals	(13,516		)		(24,780		)	Net realized investments gains
	(13,516		)		(24,780		)	Income (loss) from continuing operations, before federal income tax
	4,731				8,673			Total federal income tax expense (benefit)
	(8,785		)		(16,107		)	Net income
Defined benefit pension and post-retirement life plans
Net actuarial loss	159				717			Loss and loss expense incurred
	631				2,702			Policy acquisition costs
	790				3,419			Income (loss) from continuing operations, before federal income tax
Prior service cost	—				7			Loss and loss expense incurred
	—				3			Policy acquisition costs
	—				10			Income (loss) from continuing operations, before federal income tax
Curtailment expense	—				16			Policy acquisition costs
	—				16			Income (loss) from continuing operations, before federal income tax
Total defined benefit pension and post-retirement life	790				3,445			Income (loss) from continuing operations, before federal income tax
	(277		)		(1,206		)	Total federal income tax expense (benefit)
	513				2,239			Net income
Total reclassifications for the period	$	(8,578	)		$	(15,031	)	Net income

Discontinued_Operations

Discontinued Operations	9 Months Ended
	Sep. 30, 2013
Discontinued Operations and Disposal Groups [Abstract]	'
Discontinued Operations	'
	Discontinued Operations
	In the fourth quarter of 2009, we sold 100% of our interest in Selective HR for proceeds to be received over a 10-year period. These proceeds were based on the ability of the purchaser to retain and generate new worksite lives though the independent agents who distribute the products. We settled the remaining receivable for an aggregate of $1.0 million, which was received in two installments during the second quarter of 2013, in full and final settlement of the contingent purchase price. An impairment of $1.5 million was recorded in the first quarter of 2013 and is included in "Loss on disposal of discontinued operations, net of tax" in the Unaudited Consolidated Statements of Income.

Litigation

Litigation	9 Months Ended
	Sep. 30, 2013
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 Insurance Subsidiaries as either: (a) liability insurers defending or providing indemnity for third-party claims brought against insureds; or (b) 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 the ultimate liability, if any, with respect to such ordinary course claims litigation, after consideration of provisions made for potential losses and costs of defense, will not be material to our consolidated financial condition, results of operations, or cash flows.
	Our Insurance Subsidiaries are also from time to time involved 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. Our Insurance Subsidiaries also are involved from time to time in individual actions in which extra-contractual damages, punitive damages, or penalties are sought, such as claims alleging bad faith in the handling of insurance claims. We believe that we have valid defenses to these cases. We expect that the ultimate liability, if any, with respect to such lawsuits, after consideration of provisions made for estimated losses, will not be material to our consolidated financial condition. Nonetheless, given the large or indeterminate amounts sought in certain of these actions, and the inherent unpredictability of litigation, an adverse outcome in certain matters could, from time to time, have a material adverse effect on our consolidated results of operations or cash flows in particular quarterly or annual periods.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	At September 30, 2013, we had contractual obligations that expire at various dates through 2026 to invest up to an additional $58.9 million in alternative and other investments. There is no certainty that all of such additional investments will be required.

Statements_of_Cash_Flow_Tables

Statements of Cash Flow (Tables)	9 Months Ended
	Sep. 30, 2013
Supplemental Cash Flow Information [Abstract]	'
Schedule of Cash Flow, Supplemental Disclosures	'
		Nine Months ended September 30,
	($ in thousands)	2013		2012
	Cash paid during the period for:
	Interest	$	13,325	11,504
	Federal income tax	17,000		6,300

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2013
Investments [Line Items]	'
Schedule of Held-to-maturity Securities	'
	September 30, 2013
	($ in thousands)	Amortized Cost			Net		Carrying			Unrecognized		Unrecognized Holding		Fair
					Unrealized Gains		Value			Holding		Losses		Value
					(Losses)					Gains
	Foreign government	$	5,292		151		5,443			122		—		5,565
	Obligations of state and political subdivisions	372,281			4,065		376,346			19,297		—		395,643
	Corporate securities	29,228			(466	)	28,762			3,015		—		31,777
	Asset-backed securities (“ABS”)	5,890			(755	)	5,135			776		—		5,911
	Commercial mortgage-backed securities (“CMBS”)	7,241			(965	)	6,276			3,357		—		9,633
	Total HTM fixed maturity securities	$	419,932		2,030		421,962			26,567		—		448,529
	December 31, 2012
	($ in thousands)	Amortized Cost			Net		Carrying			Unrecognized		Unrecognized Holding		Fair
					Unrealized Gains		Value			Holding		Losses		Value
					(Losses)					Gains
	Foreign government	$	5,292		212		5,504			367		—		5,871
	Obligations of state and political subdivisions	491,180			6,769		497,949			28,996		(23	)	526,922
	Corporate securities	38,285			(812	)	37,473			4,648		—		42,121
	ABS	6,980			(1,052	)	5,928			1,170		—		7,098
	CMBS	8,406			(1,191	)	7,215			5,434		—		12,649
	Total HTM fixed maturity securities	$	550,143		3,926		554,069			40,615		(23	)	594,661
Schedule Of Available For Sale Securities	'
	September 30, 2013
	($ in thousands)	Cost/			Unrealized		Unrealized			Fair
		Amortized			Gains		Losses			Value
		Cost
	U.S. government and government agencies	$	169,163		11,953		(330	)		180,786
	Foreign government	28,797			996		(84	)		29,709
	Obligations of states and political subdivisions	918,403			27,705		(16,610	)		929,498
	Corporate securities	1,629,698			47,932		(14,479	)		1,663,151
	ABS	150,179			1,063		(476	)		150,766
	CMBS1	152,464			2,747		(3,263	)		151,948
	Residential mortgage-backed	525,047			8,932		(6,405	)		527,574
	securities (“RMBS”)2
	AFS fixed maturity securities	3,573,751			101,328		(41,647	)		3,633,432
	AFS equity securities	158,323			24,061		(1,878	)		180,506
	Total AFS securities	$	3,732,074		125,389		(43,525	)		3,813,938
	December 31, 2012
	($ in thousands)	Cost/			Unrealized		Unrealized			Fair
		Amortized			Gains		Losses			Value
		Cost
	U.S. government and government agencies	$	241,874		17,219		(1	)		259,092
	Foreign government	28,813			1,540		(124	)		30,229
	Obligations of states and political subdivisions	773,953			44,398		(327	)		818,024
	Corporate securities	1,368,954			81,696		(402	)		1,450,248
	ABS	126,330			2,319		(9	)		128,640
	CMBS1	133,763			4,572		(1,216	)		137,119
	RMBS2	456,996			15,961		(296	)		472,661
	AFS fixed maturity securities	3,130,683			167,705		(2,375	)		3,296,013
	AFS equity securities	132,441			19,400		(459	)		151,382
	Total AFS securities	$	3,263,124		187,105		(2,834	)		3,447,395
	1 CMBS includes government guaranteed agency securities with a fair value of $35.5 million at September 30, 2013 and $48.9 million at December 31, 2012.
	2 RMBS includes government guaranteed agency securities with a fair value of $61.4 million at September 30, 2013 and $91.0 million at December 31, 2012.
Schedule of Fair Value and Gross Pre-Tax Net Unrealized/Unrecognized Loss of Securities by Length of Time	'
	September 30, 2013	Less than 12 months					12 months or longer
	($ in thousands)	Fair Value			Unrealized		Fair Value			Unrealized
					Losses1					Losses1
	AFS securities
	U.S. government and government agencies	$	13,173		(327	)	510			(3	)
	Foreign government	1,056			(12	)	2,925			(72	)
	Obligations of states and political subdivisions	417,866			(16,610	)	—			—
	Corporate securities	422,816			(14,200	)	3,837			(279	)
	ABS	87,786			(471	)	302			(5	)
	CMBS	69,322			(2,771	)	2,030			(492	)
	RMBS	202,428			(6,231	)	1,579			(174	)
	Total fixed maturity securities	1,214,447			(40,622	)	11,183			(1,025	)
	Equity securities	35,275			(1,878	)	—			—
	Subtotal	$	1,249,722		(42,500	)	11,183			(1,025	)
		Less than 12 months								12 months or longer
	($ in thousands)	Fair			Unrealized		Unrecognized			Fair		Unrealized		Unrecognized
		Value			Losses1		Gains2			Value		Losses1		Gains2
	HTM securities
	Obligations of states and political subdivisions	$	492		(20	)	19			571		(24	)	17
	ABS	—			—		—			2,476		(690	)	642
	Subtotal	$	492		(20	)	19			3,047		(714	)	659
	Total AFS and HTM	$	1,250,214		(42,520	)	19			14,230		(1,739	)	659
	December 31, 2012	Less than 12 months					12 months or longer
	($ in thousands)	Fair			Unrealized		Fair Value			Unrealized
		Value			Losses1					Losses1
	AFS securities
	U.S. government and government agencies	$	518		(1	)	—			—
	Foreign government	—			—		2,871			(124	)
	Obligations of states and political subdivisions	32,383			(327	)	—			—
	Corporate securities	50,880			(402	)	—			—
	ABS	9,137			(9	)	—			—
	CMBS	7,637			(19	)	11,830			(1,197	)
	RMBS	8,710			(59	)	5,035			(237	)
	Total fixed maturity securities	109,265			(817	)	19,736			(1,558	)
	Equity securities	15,901			(459	)	—			—
	Subtotal	$	125,166		(1,276	)	19,736			(1,558	)
		Less than 12 months								12 months or longer
	($ in thousands)	Fair			Unrealized		Unrecognized			Fair		Unrealized		Unrecognized
		Value			Losses1		Gains2			Value		Losses1		Gains2
	HTM securities
	Obligations of states and political subdivisions	$	1,218		(33	)	29			1,108		(47	)	38
	ABS	—			—		—			2,860		(840	)	753
	Subtotal	1,218			(33	)	29			3,968		(887	)	791
	Total AFS and HTM	$	126,384		(1,309	)	29			23,704		(2,445	)	791
	1 Gross unrealized losses include non-OTTI unrealized amounts and OTTI losses recognized in AOCI.  In addition, this column includes remaining unrealized gain or loss amounts on securities that were transferred to an HTM designation in the first quarter of 2009 for those securities that are in a net unrealized/unrecognized loss position.
	2 Unrecognized gains represent fair value fluctuations from the later of:  (i) the date a security is designated as HTM; or (ii) the date that an OTTI charge is recognized on an HTM security.
Schedule Of The Number Of Securities In An Unrealized Unrecognized Loss Position	'
	($ in thousands)
	September 30, 2013					December 31, 2012
	Number of	% of Market/Book	Unrealized/			Number of	% of	Unrealized/
	Issues		Unrecognized Loss			Issues	Market/Book	Unrecognized
								Loss
	501	80% - 99%	$	43,295		100	80% - 99%	$	2,701
	—	60% - 79%	—			1	60% - 79%	233
	1	40% - 59%	286			—	40% - 59%	—
	—	20% - 39%	—			—	20% - 39%	—
	—	0% - 19%	—			—	0% - 19%	—
			$	43,581				$	2,934
Schedule Of Other Investment Portfolio By Strategy And Remaining Commitment Amount Associated With Each Strategy	'
	Other Investments	Carrying Value					September 30,
							2013
	($ in thousands)	September 30,			December 31,		Remaining Commitment
		2013			2012
	Alternative Investments
	Secondary private equity	$	25,954		28,032		7,703
	Private equity	18,951			18,344		10,502
	Energy/power generation	17,049			18,640		7,076
	Mezzanine financing	12,921			12,692		18,796
	Real estate	12,385			11,751		10,205
	Distressed debt	11,911			12,728		2,964
	Venture capital	7,018			7,477		400
	Total alternative investments	106,189			109,664		57,646
	Other securities	1,884			4,412		1,289
	Total other investments	$	108,073		114,076		58,935
Schedule Of Aggregated Summarized Income Statement Financial Information For Partnerhips In Our Alternative Investment Portfolio	'
	Income Statement Information	Quarter ended June 30,					Nine Months ended June 30,
	($ in millions)	2013			2012		2013			2012
	Net investment income	$	97.8		80		352.8			170.1
	Realized gains	162.8			19.6		762.5			1,004.90
	Net change in unrealized depreciation	104.8			(117.1	)	85.9			(551.1	)
	Net income (loss)	$	365.4		(17.5	)	1,201.20			623.9
	Selective’s insurance subsidiaries’ other investments income	$	2.6		0.5		10.1			5.5
Schedule of Net Investment Income earned	'
		Quarter ended September 30,					Nine Months ended September 30,
	($ in thousands)	2013			2012		2013			2012
	Fixed maturity securities	$	30,569		30,839		90,956			93,948
	Equity securities	1,341			1,268		4,422			3,785
	Short-term investments	21			36		102			103
	Other investments	2,639			497		10,110			5,460
	Miscellaneous income	—			41		—			105
	Investment expenses	(2,113		)	(2,031	)	(6,260	)		(6,117	)
	Net investment income earned	$	32,457		30,650		99,330			97,284
OTTI By Asset Type	'
	Third Quarter 2013	Gross			Included in Other		Recognized in
					Comprehensive		Earnings
	($ in thousands)				Income (“OCI”)
	Equity securities	$	680		—		680
	OTTI losses	$	680		—		680
	Third Quarter 2012	Gross			Included in OCI		Recognized in Earnings
	($ in thousands)
	AFS fixed maturity securities
	ABS	$	36		—		36
	CMBS	(1,504		)	(2,023	)	519
	Total AFS fixed maturities	(1,468		)	(2,023	)	555
	Equity securities	2,389			—		2,389
	OTTI losses	$	921		(2,023	)	2,944
	Nine Months 2013	Gross			Included in OCI		Recognized in
	($ in thousands)						Earnings
	HTM fixed maturity securities:
	ABS	$	(44	)	(47	)	3
	Total HTM fixed maturity securities	(44		)	(47	)	3
	AFS fixed maturity securities:
	RMBS	(22		)	(30	)	8
	Total AFS fixed maturity securities	(22		)	(30	)	8
	Equity securities	1,326			—		1,326
	Total AFS securities	1,304			(30	)	1,334
	Other investments	1,847			—		1,847
	OTTI losses	$	3,107		(77	)	3,184
	Nine Months 2012	Gross			Included in OCI		Recognized in
	($ in thousands)						Earnings
	AFS fixed maturity securities
	ABS	$	98		—		98
	CMBS	(1,396		)	(2,023	)	627
	RMBS	(44		)	(218	)	174
	Total AFS fixed maturity securities	(1,342		)	(2,241	)	899
	Equity securities	2,560			—		2,560
	OTTI losses	$	1,218		(2,241	)	3,459
Gross Credit Loss Impairments on Fixed Maturity Securities for Which a Portion of the OTTI Charge was Recognized in OCI	'
		Quarter ended September 30,
	($ in thousands)	2013			2012
	Balance, beginning of period	$	7,488		6,775
	Addition for the amount related to credit loss for which an OTTI was not previously recognized	—			—
	Reductions for securities sold during the period	—			—
	Reductions for securities for which the amount previously recognized in OCI was recognized in earnings because of intention or potential requirement to sell before recovery of amortized cost	—			—
	Reductions for securities for which the entire amount previously recognized in OCI was recognized in earnings due to a decrease in cash flows expected	—			—
	Additional increases to the amount related to credit loss for which an OTTI was previously recognized	—			519
	Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	—			—
	Balance, end of period	$	7,488		7,294
		Nine Months ended September 30,
	($ in thousands)	2013			2012
	Balance, beginning of period	$	7,477		6,602
	Addition for the amount related to credit loss for which an OTTI was not previously recognized	—			—
	Reductions for securities sold during the period	—			—
	Reductions for securities for which the amount previously recognized in OCI was recognized in earnings because of intention or potential requirement to sell before recovery of amortized cost	—			—
	Reductions for securities for which the entire amount previously recognized in OCI was recognized in earnings due to a decrease in cash flows expected	—			—
	Additional increases to the amount related to credit loss for which an OTTI was previously recognized	11			692
	Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	—			—
	Balance, end of period	$	7,488		7,294
Components of Net Realized Gains Excluding OTTI Charges	'
		Quarter ended September 30,					Nine Months ended September 30,
	($ in thousands)	2013			2012		2013			2012
	HTM fixed maturity securities
	Gains	$	32		40		35			195
	Losses	(37		)	(90	)	(86	)		(196	)
	AFS fixed maturity securities
	Gains	662			2,168		2,580			2,941
	Losses	(31		)	(262	)	(330	)		(379	)
	AFS equity securities
	Gains	13,801			—		24,272			4,775
	Losses	(236		)	—		(407	)		(428	)
	Short-term investments
	Losses	—			—		—			(2	)
	Other Investments
	Gains	—			—		—			1
	Losses	(80		)	—		(940	)		—
	Total other net realized investment gains	14,111			1,856		25,124			6,907
	Total OTTI charges recognized in earnings	(680		)	(2,944	)	(3,184	)		(3,459	)
	Total net realized gains (losses)	$	13,431		(1,088	)	21,940			3,448
Held To Maturity Fixed Maturity Securities [Member]	'
Investments [Line Items]	'
Schedule Of Fixed Maturity Securities By Contractual Maturities	'
	($ in thousands)	Carrying Value			Fair Value
	Due in one year or less	$	72,099		74,953
	Due after one year through five years	312,318			331,927
	Due after five years through 10 years	34,747			38,176
	Due after 10 years	2,798			3,473
	Total HTM fixed maturity securities	$	421,962		448,529
AFS Fixed Maturity Securities [Member]	'
Investments [Line Items]	'
Schedule Of Fixed Maturity Securities By Contractual Maturities	'
	($ in thousands)	Fair Value
	Due in one year or less	$	324,743
	Due after one year through five years	1,951,770
	Due after five years through 10 years	1,329,795
	Due after 10 years	27,124
	Total AFS fixed maturity securities	$	3,633,432

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
The Carrying Amounts and Estimated Fair Values of Financial Instruments	'
			September 30, 2013					December 31, 2012
	($ in thousands)		Carrying Amount			Fair		Carrying Amount		Fair
						Value				Value
	Financial Assets
	Fixed maturity securities:
	HTM		$	421,962		448,529		554,069		594,661
	AFS		3,633,432			3,633,432		3,296,013		3,296,013
	Equity securities, AFS		180,506			180,506		151,382		151,382
	Short-term investments		172,087			172,087		214,479		214,479
	Receivable for proceeds related to sale of Selective HR Solution (“Selective HR”)		—			—		2,705		2,705
	Financial Liabilities
	Notes payable:
	2.90% borrowings from FHLBI		13,000			13,392		13,000		13,595
	1.25% borrowings from FHLBI		45,000			45,171		45,000		45,590
	7.50% Junior Notes		—			—		100,000		101,480
	6.70% Senior Notes		99,492			100,200		99,475		107,707
	7.25% Senior Notes		49,915			51,858		49,912		52,689
	5.875% Senior Notes		185,000			153,550		—		—
	Total notes payable		$	392,407		364,171		307,387		321,061
Quantitative Disclosures of Our Financial Assets That Were Measured At Fair Value	'
	September 30, 2013					Fair Value Measurements Using
	($ in thousands)		Assets			Quoted Prices in		Significant Other		Significant Unobservable
			Measured at			Active Markets for		Observable		Inputs
			Fair Value			Identical Assets/		Inputs		(Level 3)
			at 9/30/13			Liabilities (Level 1)1		(Level 2)1
	Description
	Measured on a recurring basis:
	AFS:
	U.S. government and government agencies		$	180,786		50,871		129,915		—
	Foreign government		29,709			—		29,709		—
	Obligations of states and political subdivisions		929,498			—		929,498		—
	Corporate securities		1,663,151			—		1,663,151		—
	ABS		150,766			—		144,804		5,962
	CMBS		151,948			—		150,339		1,609
	RMBS		527,574			—		527,574		—
	Total AFS fixed maturity securities		3,633,432			50,871		3,574,990		7,571
	Equity securities		180,506			177,606		—		2,900
	Short-term investments		172,087			172,087		—		—
	Total assets		$	3,986,025		400,564		3,574,990		10,471
	1	There were no transfers of securities between Level 1 and Level 2.
	December 31, 2012					Fair Value Measurements Using
	($ in thousands)		Assets			Quoted Prices in		Significant		Significant Unobservable
			Measured at			Active Markets for		Other Observable		Inputs
			Fair Value			Identical Assets/Liabilities		Inputs		(Level 3)
			at 12/31/12			(Level 1)1		(Level 2)1
	Description
	Measured on a recurring basis:
	AFS:
	U.S. government and government agencies		$	259,092		115,861		123,442		19,789
	Foreign government		30,229			—		30,229		—
	Obligations of states and political subdivisions		818,024			—		818,024		—
	Corporate securities		1,450,247			—		1,447,301		2,946
	ABS		128,640			—		122,572		6,068
	CMBS		137,119			—		129,957		7,162
	RMBS		472,662			—		472,662		—
	Total AFS fixed maturity securities		3,296,013			115,861		3,144,187		35,965
	Equity securities		151,382			147,775		—		3,607
	Short-term investments		214,479			214,479		—		—
	Receivable for proceeds related to sale of Selective HR		2,705			—		—		2,705
	Total assets		$	3,664,579		478,115		3,144,187		42,277
	1	There were no transfers of securities between Level 1 and Level 2.
Summary of the Changes in Fair Value of Securities measured Using Level 3 Inputs	'
	September 30, 2013
	($ in thousands)		Government			Corporate		ABS		CMBS		Equity		Receivable for		Total
														Proceeds
														Related to Sale
														of Selective HR
	Fair value, December 31, 2012		$	19,789		2,946		6,068		7,162		3,607		2,705		42,277
	Total net (losses) gains for the period included in:
	OCI1		(537		)	(7	)	(106	)	681		3,935		—		3,966
	Net income2,3		(76		)	—		—		354		—		(1,480	)	(1,202	)
	Purchases		—			—		—		—		—		—		—
	Sales		—			—		—		—		—		—		—
	Issuances		—			—		—		—		—		—		—
	Settlements		(1,847		)	(168	)	—		(1,603	)	—		(225	)	(3,843	)
	Transfers into Level 3		—			—		—		—		—		—		—
	Transfers out of Level 3		(17,329		)	(2,771	)	—		(4,985	)	(4,642	)	(1,000	)	(30,727	)
	Fair value, September 30, 2013		$	—		—		5,962		1,609		2,900		—		10,471
	1 Amounts are reported in “Unrealized holding gains (losses) arising during period” on the Unaudited Consolidated Statements of Comprehensive Income.
	2 Amounts are reported in “Net realized gains (losses)” for realized gains and “Net investment income earned” for amortization of securities on the Unaudited Consolidated Statements of Income.
	3 For the receivable related to the sale of Selective HR, amounts in “Loss on disposal of discontinued operations, net of tax” relate to an impairment charge and amounts in “Other income” relate to interest accretion on the Unaudited Consolidated Statements of Income.
	31-Dec-12
	($ in thousands)		Government			Corporate		ABS		CMBS		Equity		Receivable for		Total
														Proceeds
														Related to Sale
														of Selective HR
	Fair value, December 31, 2011		$	21,741		2,603		—		354		—		3,212		27,910
	Total net (losses) gains for the period included in:
	OCI1		(22		)	185		68		858		—		—		1,089
	Net income2,3		(193		)	—		—		(51	)	—		244		—
	Purchases		—			—		7,300		5,611		—		—		12,911
	Sales		—			—		—		—		—		—		—
	Issuances		—			—		—		—		—		—		—
	Settlements		(1,737		)	(630	)	—		(624	)	—		(751	)	(3,742	)
	Transfers into Level 3		—			788		—		8,247		3,607		—		12,642
	Transfers out of Level 3		—			—		(1,300	)	(7,233	)	—		—		(8,533	)
	Fair value, December 31, 2012		$	19,789		2,946		6,068		7,162		3,607		2,705		42,277
	1 Amounts are reported in “Unrealized holding gains arising during period” on the Consolidated Statements of Comprehensive Income in our 2012 Annual Report.
	2 Amounts are reported in “Net realized gains (losses)” for realized gains and losses and “Net investment income earned” for amortization for the CMBS securities on the Consolidated Statements of Income in our 2012 Annual Report.
	3 Amounts are reported in “Other income” for the receivable related to the sale of Selective HR on the Consolidated Statements of Income in our 2012 Annual Report and are related to interest accretion on the receivable.
Quantitative Information of Our Financial Assets and Liabilities That Were Disclosed at Fair Value	'
	:
	September 30, 2013					Fair Value Measurements Using
	($ in thousands)		Assets/			Quoted Prices in		Significant Other		Significant
			Liabilities			Active Markets for		Observable		Unobservable
			Disclosed at			Identical Assets/		Inputs		Inputs
			Fair Value at 9/30/2013			Liabilities		(Level 2)		(Level 3)
						(Level 1)
	Financial Assets
	HTM:
	Foreign government		$	5,565		—		5,565		—
	Obligations of states and political subdivisions		395,643			—		395,643		—
	Corporate securities		31,777			—		31,777		—
	ABS		5,911			—		4,854		1,057
	CMBS		9,633			—		9,633		—
	Total HTM fixed maturity securities		$	448,529		—		447,472		1,057
	Financial Liabilities
	Notes payable:
	2.90% borrowings from FHLBI		$	13,392		—		13,392		—
	1.25% borrowings from FHLBI		45,171			—		45,171		—
	6.70% Senior Notes		100,200			—		100,200		—
	7.25% Senior Notes		51,858			—		51,858		—
	5.875% Senior Notes		153,550			153,550		—		—
	Total notes payable		$	364,171		153,550		210,621		—
	December 31, 2012					Fair Value Measurements Using
	($ in thousands)		Assets/			Quoted Prices in		Significant Other		Significant
			Liabilities			Active Markets for		Observable		Unobservable
			Disclosed at			Identical Assets/		Inputs		Inputs
			Fair Value at 12/31/2012			Liabilities		(Level 2)		(Level 3)
						(Level 1)
	Financial Assets
	HTM:
	Foreign government		$	5,871		—		5,871		—
	Obligations of states and political subdivisions		526,922			—		526,922		—
	Corporate securities		42,121			—		37,289		4,832
	ABS		7,097			—		5,698		1,399
	CMBS		12,650			—		12,650		—
	Total HTM fixed maturity securities		$	594,661		—		588,430		6,231
	Financial Liabilities
	Notes payable:
	2.90% borrowings from FHLBI		$	13,595		—		13,595		—
	1.25% borrowings from FHLBI		45,590			—		45,590		—
	7.50% Junior Notes		101,480			101,480		—		—
	6.70% Senior Notes		107,707			107,707		—		—
	7.25% Senior Notes		52,689			—		52,689		—
	Total notes payable		$	321,061		209,187		111,874		—

Reinsurance_Tables

Reinsurance (Tables)	9 Months Ended
	Sep. 30, 2013
Reinsurance Disclosures [Abstract]	'
List Of Direct, Assumed, And Ceded Reinsurance Amounts	'
		Quarter ended September 30,					Nine Months ended September 30,
	($ in thousands)	2013			2012		2013		2012
	Premiums written:
	Direct	$	570,849		520,943		1,650,855		1,504,429
	Assumed	22,053			17,976		34,913		44,712
	Ceded	(100,154		)	(88,401	)	(280,719	)	(252,888	)
	Net	$	492,748		450,518		1,405,049		1,296,253
	Premiums earned:
	Direct	$	518,307		474,055		1,516,454		1,389,373
	Assumed	11,066			18,595		32,480		49,683
	Ceded	(91,805		)	(86,425	)	(264,174	)	(261,790	)
	Net	$	437,568		406,225		1,284,760		1,177,266
	Loss and loss expense incurred:
	Direct	$	350,648		327,883		1,055,248		881,537
	Assumed	7,264			13,970		22,758		35,039
	Ceded	(74,595		)	(69,602	)	(245,246	)	(103,516	)
	Net	$	283,317		272,251		832,760		813,060
Ceded Premiums and Losses Related to Flood Operations	'
	NFIP	Quarter ended September 30,					Nine Months ended September 30,
	($ in thousands)	2013			2012		2013		2012
	Ceded premiums written	$	(64,196	)	(58,923	)	(183,364	)	(171,172	)
	Ceded premiums earned	(57,920		)	(53,222	)	(169,697	)	(157,895	)
	Ceded loss and loss expense incurred	(34,879		)	(32,702	)	(162,780	)	(24,534	)

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Revenue from Continuing Operations By Segment	'
	Revenue by Segment	Quarter ended September 30,					Nine Months ended September 30,
	($ in thousands)	2013			2012		2013		2012
	Standard Insurance Operations:
	Net premiums earned:
	Commercial automobile	$	79,138		72,758		230,191		214,782
	Workers compensation	66,510			65,592		197,449		198,064
	General liability	100,925			93,763		298,394		276,538
	Commercial property	57,004			52,197		165,356		151,945
	Businessowners’ policies	19,629			17,749		56,794		51,872
	Bonds	4,705			4,713		14,244		14,076
	Other	3,051			2,921		9,036		9,202
	Total standard Commercial Lines	330,962			309,693		971,464		916,479
	Personal automobile	38,513			38,295		115,432		113,648
	Homeowners	32,374			29,919		95,211		86,685
	Other	3,827			3,591		10,655		10,037
	Total standard Personal Lines	74,714			71,805		221,298		210,370
	Total Standard Insurance Operations net premiums earned	405,676			381,498		1,192,762		1,126,849
	Miscellaneous income	3,342			1,009		9,590		6,904
	Total Standard Insurance Operations revenue	409,018			382,507		1,202,352		1,133,753
	E&S Insurance Operations:
	Net premiums earned	31,892			24,727		91,998		50,417
	Investments:
	Net investment income	32,457			30,650		99,330		97,284
	Net realized investment gains (losses)	13,431			(1,088	)	21,940		3,448
	Total investment revenues	45,888			29,562		121,270		100,732
	Total all segments	486,798			436,796		1,415,620		1,284,902
	Other income	15			76		87		225
	Total revenues from continuing operations	$	486,813		436,872		1,415,707		1,285,127
Income From Continuing Operations, Before Federal Income Tax	'
	Income from Continuing Operations before Federal Income Tax	Quarter ended September 30,					Nine Months ended September 30,
	($ in thousands)	2013			2012		2013		2012
	Standard Insurance Operations:
	Commercial Lines underwriting gain (loss)	$	8,776		(651	)	24,621		(14,666	)
	Personal Lines underwriting gain	1,362			7,220		4,360		2,903
	Total Standard Insurance Operations underwriting gain (loss), before federal income tax	10,138			6,569		28,981		(11,763	)
	GAAP combined ratio	97.5		%	98.3		97.6		101
	Statutory combined ratio	96		%	96.9		96.6		100.1
	E&S Insurance Operations:
	Underwriting gain (loss)	13			(5,708	)	(2,186	)	(15,701	)
	GAAP combined ratio	100		%	123.1		102.4		131.1
	Statutory combined ratio	100.5		%	121.6		101.9		120.3
	Investments:
	Net investment income	32,457			30,650		99,330		97,284
	Net realized investment gains (losses)	13,431			(1,088	)	21,940		3,448
	Total investment income, before federal income tax	45,888			29,562		121,270		100,732
	Total all segments	56,039			30,423		148,065		73,268
	Interest expense	(5,570		)	(4,725	)	(16,971	)	(14,148	)
	General corporate and other expenses	(5,984		)	(5,384	)	(21,540	)	(16,307	)
	Income from continuing operations before federal income tax	$	44,485		20,314		109,554		42,813

Indebtedness_Indebtedness_Tabl

Indebtedness Indebtedness (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Convenants in the Line of Credit	'
		Required as of	Actual as of
		30-Sep-13	30-Sep-13
	Consolidated net worth	$785 million	$1.1 billion
	Statutory surplus	Not less than $750 million	$1.2 billion
	Debt-to-capitalization ratio1	Not to exceed 35%	26.00%
	A.M. Best financial strength rating	Minimum of A-	A
	1Calculated in accordance with the Line of Credit agreement.

Retirement_Plans_Table

Retirement Plans (Table)	9 Months Ended
	Sep. 30, 2013
Compensation and Retirement Disclosure [Abstract]	'
Funded Status Of Retirement Income Plan	'
		Retirement Income Plan
	($ in thousands)	30-Sep-13				31-Dec-12
	Change in Benefit Obligation:
	Benefit obligation, beginning of year	$	302,647			254,009
	Service cost	2,449				8,091
	Interest cost	3,303				12,981
	Actuarial (gain) losses	(11,485		)		33,596
	Benefits paid	(1,598		)		(6,030	)
	Impact of curtailment	(29,603		)		—
	Benefit obligation, end of period	$	265,713			302,647
	Change in Fair Value of Assets:
	Fair value of assets, beginning of year	$	207,150			182,614
	Actual return on plan assets, net of expenses	6,760				21,896
	Contribution by employer to funded plans	2,650				8,550
	Contribution by employer to unfunded plans	30				120
	Benefits paid	(1,598		)		(6,030	)
	Fair value of assets, end of period	$	214,992			207,150
	Funded status	$	(50,721	)		(95,497	)
Schedule of Amounts Recognized in Balance Sheet	'
	Amount Recognized in Consolidated Balance Sheet:
	Liabilities	$	(50,721	)		(95,497	)
	Net pension liability, end of period	$	(50,721	)		(95,497	)
Amounts recognized in AOCI	'
	Amount Recognized in AOCI:
	Prior service cost	$	—			26
	Net actuarial loss	57,543				103,365
	Total	$	57,543			103,391
Other Information	'
	Other Information:
	Accumulated benefit obligation	$	257,412			265,899
Weighted-Average Liability Assumptions	'
	Weighted-Average Liability Assumptions:
	Discount Rate	4.66	%		4.42
	Rate of compensation increase	4	%		4
Components Of Net Periodic Benefit Cost And Other Amounts Recognized In Other Comprehensive Income	'
		Retirement Income Plan							Retirement Life Plan
		Quarter ended September 30,							Quarter ended September 30,
	($ in thousands)	2013				2012			2013		2012
	Components of Net Periodic Benefit Cost and Other Amounts Recognized in OCI:
	Net Periodic Benefit Cost:
	Service cost	$	1,857			2,154			—		—
	Interest cost	3,053				3,230			69		73
	Expected return on plan assets	(3,986		)		(3,547	)		—		—
	Amortization of unrecognized prior service cost	—				38			—		—
	Amortization of unrecognized net actuarial loss	772				1,383			18		8
	Total net periodic cost	$	1,696			3,258			87		81
	Other Changes in Plan Assets and Benefit Obligations Recognized in OCI:
	Reversal of amortization of net actuarial loss	$	(772	)		(1,383	)		(18	)	(8	)
	Reversal of amortization of prior service cost	—				(38	)		—		—
	Total recognized in OCI	$	(772	)		(1,421	)		(18	)	(8	)
	Total recognized in net periodic benefit cost and OCI	$	924			1,837			69		73
		Retirement Income Plan							Retirement Life Plan
		Nine Months ended September 30,							Nine Months ended September 30,
	($ in thousands)	2013				2012			2013		2012
	Components of Net Periodic Benefit Cost and Other Amounts Recognized in OCI:
	Net Periodic Benefit Cost:
	Service cost	$	6,163			6,462			—		—
	Interest cost	9,407				9,690			208		221
	Expected return on plan assets	(11,819		)		(10,641	)		—		—
	Amortization of unrecognized prior service cost	10				113			—		—
	Amortization of unrecognized net actuarial loss	3,366				4,149			53		23
	Curtailment expense	16				—			—		—
	Total net periodic cost	$	7,143			9,773			261		244
	Other Changes in Plan Assets and Benefit Obligations Recognized in OCI:
	Net actuarial gain due to curtailment	$	(44,000	)		—			—		—
	Reversal of amortization of net actuarial loss	(3,366		)		(4,149	)		(53	)	(23	)
	Reversal of amortization of prior service cost	(10		)		(113	)		—		—
	Curtailment expense	(16		)		—			—		—
	Total recognized in OCI	$	(47,392	)		(4,262	)		(53	)	(23	)
	Total recognized in net periodic benefit cost and OCI	$	(40,249	)		5,511			208		221
Schedule Of Weighted-Average Expense Assumption	'
		Retirement Income Plan					Retirement Life Plan
		Nine Months ended September 30,					Nine Months ended September 30,
		2013			2012		2013			2012
	Weighted-Average Expense Assumptions:
	Discount rate	4.66	%		5.16		4.42	%		5.16
	Expected return on plan assets	7.4			7.75		—			—
	Rate of compensation increase	4			4		—			—
Schedule of Expected Benefit Payments	'
	($ in thousands)	Retirement Income Plan
	Benefits Expected to be Paid in Future Years
	Fiscal Years:
	2013	$	7,586
	2014	8,384
	2015	9,148
	2016	9,942
	2017	10,810
	2018-2022	67,447

Comprehensive_Income_Tables

Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2013
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]	'
Components of Comprehensive Income-Gross and Net of Tax	'
	Nine Months 2013
	($ in thousands)		Gross				Tax		Net
	Net income		$	108,019			26,936		81,083
	Components of OCI:
	Unrealized losses on investment securities:
	Unrealized holding losses during the period		(77,810		)		(27,234	)	(50,576	)
	Non-credit OTTI recognized in OCI		77				27		50
	Amounts reclassified into net income:
	HTM securities		(1,803		)		(631	)	(1,172	)
	Non-credit OTTI		14				5		9
	Realized gains on AFS securities		(24,780		)		(8,673	)	(16,107	)
	Net unrealized losses		(104,302		)		(36,506	)	(67,796	)
	Defined benefit pension and post-retirement plans:
	Net actuarial gain		44,000				15,400		28,600
	Amounts reclassified into net income:
	Net actuarial loss		3,419				1,197		2,222
	Prior service cost		10				4		6
	Curtailment expense		16				5		11
	Defined benefit pension and post-retirement plans		47,445				16,606		30,839
	Other comprehensive loss		(56,857		)		(19,900	)	(36,957	)
	Comprehensive income		$	51,162			7,036		44,126
	Nine Months 2012
	($ in thousands)		Gross				Tax		Net
	Net income		$	42,813			6,158		36,655
	Components of OCI:
	Unrealized gains on investment securities:
	Unrealized holding gains during the period		64,273				22,496		41,777
	Non-credit OTTI recognized in OCI		2,241				784		1,457
	Amounts reclassified into net income:
	HTM securities		(1,901		)		(665	)	(1,236	)
	Non-credit OTTI		272				95		177
	Realized gains on AFS securities		(3,451		)		(1,208	)	(2,243	)
	Net unrealized gains		61,434				21,502		39,932
	Defined benefit pension and post-retirement plans:
	Amounts reclassified into net income:
	Net actuarial loss		4,172				1,460		2,712
	Prior service cost		113				40		73
	Defined benefit pension and post-retirement plans		4,285				1,500		2,785
	Other comprehensive income		65,719				23,002		42,717
	Comprehensive income		$	108,532			29,160		79,372
	Third Quarter 2013
	($ in thousands)		Gross				Tax		Net
	Net income		$	44,485			11,832		32,653
	Components of OCI:
	Unrealized losses on investment securities:
	Unrealized gains during the period		9,820				3,437		6,383
	Amounts reclassified into net income:
	HTM securities		(472		)		(165	)	(307	)
	Non-credit OTTI		1				—		1
	Realized gains on AFS securities		(13,516		)		(4,731	)	(8,785	)
	Net unrealized losses		(4,167		)		(1,459	)	(2,708	)
	Defined benefit pension and post-retirement plans:
	Amounts reclassified into net income:
	Net actuarial loss		790				277		513
	Defined benefit pension and post-retirement plans		790				277		513
	Other comprehensive loss		(3,377		)		(1,182	)	(2,195	)
	Comprehensive income		$	41,108			10,650		30,458
	Third Quarter 2012
	($ in thousands)		Gross				Tax		Net
	Net income		$	20,314			2,040		18,274
	Components of OCI:
	Unrealized gains on investment securities:
	Unrealized holding gains during the period		36,620				12,817		23,803
Non-credit OTTI recognized in OCI		2,023				708		1,315
Amounts reclassified into net income:
HTM securities		(336		)		(117	)	(219	)
Non-credit OTTI		9				3		6
Realized losses on AFS securities		1,037				363		674
Net unrealized gains		39,353				13,774		25,579
Defined benefit pension and post-retirement plans:
Amounts reclassified into net income:
Net actuarial loss		1,391				487		904
Prior service cost		38				14		24
Defined benefit pension and post-retirement plans		1,429				501		928
Other comprehensive income		40,782				14,275		26,507
Comprehensive income		$	61,096			16,315		44,781
Components of Accumulated Other Comprehensive Income	'
	September 30, 2013		Net Unrealized (Loss) Gain on Investment Securities
	($ in thousands)		OTTI				HTM		All		Investments		Defined Benefit		Total AOCI
			Related				Related		Other		Subtotal		Pension and Post-Retirement Plans
	Balance, December 31, 2012		$	(1,658	)		2,594		121,391		122,327		(68,287	)	54,040
	OCI before reclassifications		50				(103	)	(50,473	)	(50,526	)	28,600		(21,926	)
	Amounts reclassified from AOCI		9				(1,172	)	(16,107	)	(17,270	)	2,239		(15,031	)
	Net current period OCI		59				(1,275	)	(66,580	)	(67,796	)	30,839		(36,957	)
	Balance, September 30, 2013		$	(1,599	)		1,319		54,811		54,531		(37,448	)	17,083
Reclassification Out Of Accumulated Other Comprehensive Income	'
		Amount Reclassified from AOCI							Affected Line Item in the Unaudited Consolidated Statement of Income
	($ in thousands)	Quarter ended September 30, 2013				Nine Months ended September 30, 2013
	OTTI related
	Amortization of non-credit OTTI losses on HTM securities
		$	1			14			Net investment income earned
		1				14			Income (loss) from continuing operations, before federal income tax
		—				(5		)	Total federal income tax expense (benefit)
		1				9			Net income
	HTM related
	Unrealized gains and losses on HTM disposals	(19		)		(170		)	Net realized investment gains
	Amortization of net unrealized gains on HTM securities	(453		)		(1,633		)	Net investment income earned
		(472		)		(1,803		)	Income (loss) from continuing operations, before federal income tax
		165				631			Total federal income tax expense (benefit)
		(307		)		(1,172		)	Net income
	Realized gains and losses on AFS
	Realized gains and losses on AFS disposals	(13,516		)		(24,780		)	Net realized investments gains
		(13,516		)		(24,780		)	Income (loss) from continuing operations, before federal income tax
		4,731				8,673			Total federal income tax expense (benefit)
		(8,785		)		(16,107		)	Net income
	Defined benefit pension and post-retirement life plans
	Net actuarial loss	159				717			Loss and loss expense incurred
		631				2,702			Policy acquisition costs
		790				3,419			Income (loss) from continuing operations, before federal income tax
	Prior service cost	—				7			Loss and loss expense incurred
		—				3			Policy acquisition costs
		—				10			Income (loss) from continuing operations, before federal income tax
	Curtailment expense	—				16			Policy acquisition costs
		—				16			Income (loss) from continuing operations, before federal income tax
	Total defined benefit pension and post-retirement life	790				3,445			Income (loss) from continuing operations, before federal income tax
		(277		)		(1,206		)	Total federal income tax expense (benefit)
		513				2,239			Net income
	Total reclassifications for the period	$	(8,578	)		$	(15,031	)	Net income

Organization_Narrative_Details

Organization (Narrative) (Details)	9 Months Ended
	Sep. 30, 2013
Number of Operating Segments	3

Statements_of_Cash_Flow_Cash_F

Statements of Cash Flow (Cash Flow Supplemental Disclosures) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Interest	$13,325,000	$11,504,000
Federal income tax	17,000,000	6,300,000
National Flood Insurance Program [Member]	'	'
Restricted Cash	$7,000,000	'

Investments_HeldToMaturity_Sec

Investments (Held-To-Maturity Securities Disclosure) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
	Securities
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	$419,932,000	$550,143,000
Net Unrealized Gains (Losses)	2,030,000	3,926,000
Carrying Value	421,962,000	554,069,000
Unrecognized Holding Gains	26,567,000	40,615,000
Unrecognized Holding Losses	0	-23,000
Fixed maturity securities, held-to-maturity, fair value	448,529,000	594,661,000
Held To Maturity securities average duration	'2 years 3 months 18 days	'
Number of held to maturity securities transferred to available-for-sale	16	'
Securities reclassified from the HTM category to AFS carrying value	39,600,000	'
Securities reclassified from the HTM category to AFS net unrecognized gain	1,400,000	'
Foreign Government [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	5,292,000	5,292,000
Net Unrealized Gains (Losses)	151,000	212,000
Carrying Value	5,443,000	5,504,000
Unrecognized Holding Gains	122,000	367,000
Unrecognized Holding Losses	0	0
Fixed maturity securities, held-to-maturity, fair value	5,565,000	5,871,000
Obligations of States and Political Subdivisions [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	372,281,000	491,180,000
Net Unrealized Gains (Losses)	4,065,000	6,769,000
Carrying Value	376,346,000	497,949,000
Unrecognized Holding Gains	19,297,000	28,996,000
Unrecognized Holding Losses	0	-23,000
Fixed maturity securities, held-to-maturity, fair value	395,643,000	526,922,000
Corporate Securities [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	29,228,000	38,285,000
Net Unrealized Gains (Losses)	-466,000	-812,000
Carrying Value	28,762,000	37,473,000
Unrecognized Holding Gains	3,015,000	4,648,000
Unrecognized Holding Losses	0	0
Fixed maturity securities, held-to-maturity, fair value	31,777,000	42,121,000
Asset-backed Securities [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	5,890,000	6,980,000
Net Unrealized Gains (Losses)	-755,000	-1,052,000
Carrying Value	5,135,000	5,928,000
Unrecognized Holding Gains	776,000	1,170,000
Unrecognized Holding Losses	0	0
Fixed maturity securities, held-to-maturity, fair value	5,911,000	7,098,000
Commercial Mortgage-backed Securities (CMBS) [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	7,241,000	8,406,000
Net Unrealized Gains (Losses)	-965,000	-1,191,000
Carrying Value	6,276,000	7,215,000
Unrecognized Holding Gains	3,357,000	5,434,000
Unrecognized Holding Losses	0	0
Fixed maturity securities, held-to-maturity, fair value	$9,633,000	$12,649,000

Investments_AvailableForSale_S

Investments (Available-For-Sale Securities Disclosure) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	$3,732,074,000		$3,263,124,000
Unrealized gains	125,389,000		187,105,000
Unrealized Losses	-43,525,000		-2,834,000
Fair Value	3,813,938,000		3,447,395,000
AFS Fixed Maturity Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	3,573,751,000		3,130,683,000
Unrealized gains	101,328,000		167,705,000
Unrealized Losses	-41,647,000		-2,375,000
Fair Value	3,633,432,000		3,296,013,000
AFS Fixed Maturity Securities [Member] | U.S. Government and Government Agencies [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	169,163,000		241,874,000
Unrealized gains	11,953,000		17,219,000
Unrealized Losses	-330,000		-1,000
Fair Value	180,786,000		259,092,000
AFS Fixed Maturity Securities [Member] | Foreign Government [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	28,797,000		28,813,000
Unrealized gains	996,000		1,540,000
Unrealized Losses	-84,000		-124,000
Fair Value	29,709,000		30,229,000
AFS Fixed Maturity Securities [Member] | Obligations of States and Political Subdivisions [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	918,403,000		773,953,000
Unrealized gains	27,705,000		44,398,000
Unrealized Losses	-16,610,000		-327,000
Fair Value	929,498,000		818,024,000
AFS Fixed Maturity Securities [Member] | Corporate Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	1,629,698,000		1,368,954,000
Unrealized gains	47,932,000		81,696,000
Unrealized Losses	-14,479,000		-402,000
Fair Value	1,663,151,000		1,450,248,000
AFS Fixed Maturity Securities [Member] | Asset-backed Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	150,179,000		126,330,000
Unrealized gains	1,063,000		2,319,000
Unrealized Losses	-476,000		-9,000
Fair Value	150,766,000		128,640,000
AFS Fixed Maturity Securities [Member] | Commercial Mortgage-backed Securities (CMBS) [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	152,464,000	[1]	133,763,000	[1]
Unrealized gains	2,747,000	[1]	4,572,000	[1]
Unrealized Losses	-3,263,000	[1]	-1,216,000	[1]
Fair Value	151,948,000	[1]	137,119,000	[1]
Government guaranteed agency securities fair value	35,500,000		48,900,000
AFS Fixed Maturity Securities [Member] | Residential Mortgage Backed Securities (RMBS) [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	525,047,000	[2]	456,996,000	[2]
Unrealized gains	8,932,000	[2]	15,961,000	[2]
Unrealized Losses	-6,405,000	[2]	-296,000	[2]
Fair Value	527,574,000	[2]	472,661,000	[2]
Government guaranteed agency securities fair value	61,400,000		91,000,000
Equity Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	158,323,000		132,441,000
Unrealized gains	24,061,000		19,400,000
Unrealized Losses	-1,878,000		-459,000
Fair Value	$180,506,000		$151,382,000
[1]	CMBS includes government guaranteed agency securities with a fair value of $35.5 million at September 30, 2013 and $48.9 million at December 31, 2012.
[2]	RMBS includes government guaranteed agency securities with a fair value of $61.4 million at September 30, 2013 and $91.0 million at December 31, 2012.

Investments_Fair_Value_and_Gro

Investments (Fair Value and Gross Pre-Tax Net Unrealized Unrecognized Loss of Securities By Length of Time) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
AFS Fair Value, Less than 12 months	$1,249,722		$125,166
AFS Unrealized Losses, Less than 12 months	-42,500	[1]	-1,276	[1]
AFS Fair Value, 12 months or longer	11,183		19,736
AFS Unrealized Losses, 12 months or longer	-1,025	[1]	-1,558	[1]
HTM Fair Value, Less than 12 months	492		1,218
HTM Unrealized Losses, Less than 12 months	-20	[1]	-33	[1]
HTM Unrecognized Gains, Less than 12 months	19	[2]	29	[2]
HTM Fair Value, 12 months or longer	3,047		3,968
HTM Unrealized Losses, 12 months or longer	-714	[1]	-887	[1]
HTM Unrecognized Gains, 12 months or longer	659	[2]	791	[2]
Total AFS and HTM Fair Value, Less than 12 months	1,250,214		126,384
Total AFS and HTM Unrealized Losses, Less than 12 months	-42,520	[1]	-1,309	[1]
Total AFS and HTM Fair Value, 12 months or longer	14,230		23,704
Total AFS and HTM Unrealized Losses, 12 months or longer	-1,739	[1]	-2,445	[1]
Obligations of States and Political Subdivisions [Member]	'		'
HTM Fair Value, Less than 12 months	492		1,218
HTM Unrealized Losses, Less than 12 months	-20	[1]	-33	[1]
HTM Unrecognized Gains, Less than 12 months	19	[2]	29	[2]
HTM Fair Value, 12 months or longer	571		1,108
HTM Unrealized Losses, 12 months or longer	-24	[1]	-47	[1]
HTM Unrecognized Gains, 12 months or longer	17	[2]	38	[2]
Asset-backed Securities [Member]	'		'
HTM Fair Value, Less than 12 months	0		0
HTM Unrealized Losses, Less than 12 months	0	[1]	0	[1]
HTM Unrecognized Gains, Less than 12 months	0	[2]	0	[2]
HTM Fair Value, 12 months or longer	2,476		2,860
HTM Unrealized Losses, 12 months or longer	-690	[1]	-840	[1]
HTM Unrecognized Gains, 12 months or longer	642	[2]	753	[2]
AFS Fixed Maturity Securities [Member]	'		'
AFS Fair Value, Less than 12 months	1,214,447		109,265
AFS Unrealized Losses, Less than 12 months	-40,622	[1]	-817	[1]
AFS Fair Value, 12 months or longer	11,183		19,736
AFS Unrealized Losses, 12 months or longer	-1,025	[1]	-1,558	[1]
AFS Fixed Maturity Securities [Member] | U.S. Government and Government Agencies [Member]	'		'
AFS Fair Value, Less than 12 months	13,173		518
AFS Unrealized Losses, Less than 12 months	-327	[1]	-1	[1]
AFS Fair Value, 12 months or longer	510		0
AFS Unrealized Losses, 12 months or longer	-3	[1]	0	[1]
AFS Fixed Maturity Securities [Member] | Foreign Government [Member]	'		'
AFS Fair Value, Less than 12 months	1,056		0
AFS Unrealized Losses, Less than 12 months	-12	[1]	0	[1]
AFS Fair Value, 12 months or longer	2,925		2,871
AFS Unrealized Losses, 12 months or longer	-72	[1]	-124	[1]
AFS Fixed Maturity Securities [Member] | Obligations of States and Political Subdivisions [Member]	'		'
AFS Fair Value, Less than 12 months	417,866		32,383
AFS Unrealized Losses, Less than 12 months	-16,610	[1]	-327	[1]
AFS Fair Value, 12 months or longer	0		0
AFS Unrealized Losses, 12 months or longer	0	[1]	0	[1]
AFS Fixed Maturity Securities [Member] | Corporate Securities [Member]	'		'
AFS Fair Value, Less than 12 months	422,816		50,880
AFS Unrealized Losses, Less than 12 months	-14,200	[1]	-402	[1]
AFS Fair Value, 12 months or longer	3,837		0
AFS Unrealized Losses, 12 months or longer	-279	[1]	0	[1]
AFS Fixed Maturity Securities [Member] | Asset-backed Securities [Member]	'		'
AFS Fair Value, Less than 12 months	87,786		9,137
AFS Unrealized Losses, Less than 12 months	-471	[1]	-9	[1]
AFS Fair Value, 12 months or longer	302		0
AFS Unrealized Losses, 12 months or longer	-5	[1]	0	[1]
AFS Fixed Maturity Securities [Member] | Commercial Mortgage-backed Securities (CMBS) [Member]	'		'
AFS Fair Value, Less than 12 months	69,322		7,637
AFS Unrealized Losses, Less than 12 months	-2,771	[1]	-19	[1]
AFS Fair Value, 12 months or longer	2,030		11,830
AFS Unrealized Losses, 12 months or longer	-492	[1]	-1,197	[1]
AFS Fixed Maturity Securities [Member] | Residential Mortgage Backed Securities (RMBS) [Member]	'		'
AFS Fair Value, Less than 12 months	202,428		8,710
AFS Unrealized Losses, Less than 12 months	-6,231	[1]	-59	[1]
AFS Fair Value, 12 months or longer	1,579		5,035
AFS Unrealized Losses, 12 months or longer	-174	[1]	-237	[1]
Equity Securities [Member]	'		'
AFS Fair Value, Less than 12 months	35,275		15,901
AFS Unrealized Losses, Less than 12 months	-1,878	[1]	-459	[1]
AFS Fair Value, 12 months or longer	0		0
AFS Unrealized Losses, 12 months or longer	$0	[1]	$0	[1]
[1]	Gross unrealized losses include non-OTTI unrealized amounts and OTTI losses recognized in AOCI. In addition, this column includes remaining unrealized gain or loss amounts on securities that were transferred to an HTM designation in the first quarter of 2009 for those securities that are in a net unrealized/unrecognized loss position.
[2]	Unrecognized gains represent fair value fluctuations from the later of: (i) the date a security is designated as HTM; or (ii) the date that an OTTI charge is recognized on an HTM security.

Investments_Number_of_Securiti

Investments (Number of Securities in an Unrealized Unrecognized Loss Position) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
	Securities	Securities
Schedule of Available-for-sale Securities [Line Items]	'	'
Unrealized Unrecognized Losses Period Increase	($40,600,000)	'
Number of securities in an unrealized/unrecognized loss position	502	101
Securities In Unrealized Unrecognized Loss Position For More Than Twelve Months	1,100,000	1,700,000
Unrealized Unrecognized Loss	43,581,000	2,934,000
Eighty Percent to Ninety-Nine Percent [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities in an unrealized/unrecognized loss position	501	100
Unrealized Unrecognized Loss	43,295,000	2,701,000
Sixty Percent to Seventy-Nine Percent [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities in an unrealized/unrecognized loss position	0	1
Unrealized Unrecognized Loss	0	233,000
Forty Percent to Fifty-Nine Percent [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities in an unrealized/unrecognized loss position	1	0
Unrealized Unrecognized Loss	286,000	0
Twenty Percent to Thirty-Nine Percent [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities in an unrealized/unrecognized loss position	0	0
Unrealized Unrecognized Loss	0	0
Zero Percent to Nineteen Percent [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities in an unrealized/unrecognized loss position	0	0
Unrealized Unrecognized Loss	$0	$0
10 year U.S. Treasury Note [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Debt Instruments, Interest Rate, Increase (Decrease)	85	'

Investments_HTM_Fixed_Maturity

Investments (HTM Fixed Maturity Securities by Contractual Maturity) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Investments [Abstract]	'	'
Due in one year or less Carrying Value	$72,099	'
Due after one year through five years Carrying Value	312,318	'
Due after five years through 10 years Carrying Value	34,747	'
Due after 10 years Carrying Value	2,798	'
Total HTM fixed maturity securities Carrying Value	421,962	554,069
Due in one year or less Fair Value	74,953	'
Due after one year through five years Fair Value	331,927	'
Due after five years through 10 years Fair Value	38,176	'
Due after 10 years Fair Value	3,473	'
Total HTM fixed maturity securities Fair Value	$448,529	$594,661

Investments_AFS_Fixed_Maturity

Investments (AFS Fixed Maturity Securities by Contractual Maturity) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Investments [Abstract]	'	'
Due in one year or less fair value	$324,743	'
Due after one year through five years fair value	1,951,770	'
Due after five years through 10 years fair value	1,329,795	'
Due after 10 years fair value	27,124	'
Total AFS fixed maturity securities	$3,633,432	$3,296,013

Investments_Other_Investment_P

Investments (Other Investment Portfolio by Strategy and the Remaining Commitment Amount Associated With Each Strategy) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Carrying Value	$108,073	$114,076
Other Investments [Member]	'	'
Carrying Value	108,073	114,076
Remaining Commitment	58,935	'
Alternative Investments [Member]	'	'
Carrying Value	106,189	109,664
Remaining Commitment	57,646	'
Secondary Private Equity Member | Alternative Investments [Member]	'	'
Carrying Value	25,954	28,032
Remaining Commitment	7,703	'
Private Equity [Member] | Alternative Investments [Member]	'	'
Carrying Value	18,951	18,344
Remaining Commitment	10,502	'
Energy Power Generation [Member] | Alternative Investments [Member]	'	'
Carrying Value	17,049	18,640
Remaining Commitment	7,076	'
Mezzanine Financing [Member] | Alternative Investments [Member]	'	'
Carrying Value	12,921	12,692
Remaining Commitment	18,796	'
Real Estate Strategy [Member] | Alternative Investments [Member]	'	'
Carrying Value	12,385	11,751
Remaining Commitment	10,205	'
Distressed Debt [Member] | Alternative Investments [Member]	'	'
Carrying Value	11,911	12,728
Remaining Commitment	2,964	'
Venture Capital [Member] | Alternative Investments [Member]	'	'
Carrying Value	7,018	7,477
Remaining Commitment	400	'
Other Securities [Member]	'	'
Carrying Value	1,884	4,412
Remaining Commitment	$1,289	'

Investments_Aggregated_Income_

Investments (Aggregated Income Statement Summarized Financial Information for Partnerhips in our Alternative Investment Portfolio) (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Jun. 30, 2013

Jun. 30, 2012

Jun. 30, 2013

Jun. 30, 2012

Jun. 30, 2013

Jun. 30, 2012

Jun. 30, 2013

Jun. 30, 2012

Alternative Investments [Member]

Alternative Investments [Member]

Alternative Investments [Member]

Alternative Investments [Member]

Investments accounted for under the equity method [Member]

Investments accounted for under the equity method [Member]

Investments accounted for under the equity method [Member]

Investments accounted for under the equity method [Member]

Schedule of Equity Method Investments [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Net investment income

'

'

'

'

'

'

'

'

$97,800,000

$80,000,000

$352,800,000

$170,100,000

Realized (losses) gains

'

'

'

'

'

'

'

'

162,800,000

19,600,000

762,500,000

1,004,900,000

Net change in unrealized depreciation

'

'

'

'

'

'

'

'

104,800,000

-117,100,000

85,900,000

-551,100,000

Net income

'

'

'

'

'

'

'

'

365,400,000

-17,500,000

1,201,200,000

623,900,000

Net investment income earned

$32,457,000

$30,650,000

$99,330,000

$97,284,000

$2,600,000

$500,000

$10,100,000

$5,500,000

'

'

'

'

Investments_Investments_Pledge

Investments (Investments Pledged as Collateral) (Details) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'
Fixed maturity security pledged at carrying value	$61.90
Outstanding borrowing with the Federal Home Loan Bank of Indianapolis	58
Carrying Value Bonds On Deposit With Various State and Regulatory Agencies	27
Short-term Investments [Member]	'
Schedule of Available-for-sale Securities [Line Items]	'
Securities pledged as collateral	1.7
Fixed Maturity Securities [Member]	'
Schedule of Available-for-sale Securities [Line Items]	'
Securities pledged as collateral	$21.30

Investments_Net_Investment_Inc

Investments (Net Investment Income) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net investment income earned	$32,457	$30,650	$99,330	$97,284
Fixed Maturity Securities [Member]	'	'	'	'
Net investment income earned	30,569	30,839	90,956	93,948
Equity Securities [Member]	'	'	'	'
Net investment income earned	1,341	1,268	4,422	3,785
Short-term Investments [Member]	'	'	'	'
Net investment income earned	21	36	102	103
Other Investment Portfolio [Member]	'	'	'	'
Net investment income earned	2,639	497	10,110	5,460
Miscellaneous Investment Income [Member]	'	'	'	'
Net investment income earned	0	41	0	105
Investment Expenses [Member]	'	'	'	'
Net investment income earned	($2,113)	($2,031)	($6,260)	($6,117)

Investments_OTTI_by_Asset_Type

Investments (OTTI by Asset Type) (Details) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended			3 Months Ended	9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended					3 Months Ended	6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Jun. 30, 2013
					Equity Securities [Member]	Equity Securities [Member]	Equity Securities [Member]	Equity Securities [Member]	Other Investments [Member]	AFS Fixed Maturity Securities [Member]	AFS Fixed Maturity Securities [Member]	AFS Fixed Maturity Securities [Member]	AFS Fixed Maturity Securities [Member]	AFS Fixed Maturity Securities [Member]	AFS Fixed Maturity Securities [Member]	AFS Fixed Maturity Securities [Member]	AFS Fixed Maturity Securities [Member]	AFS Fixed Maturity Securities [Member]	Held To Maturity Fixed Maturity Securities [Member]	Held To Maturity Fixed Maturity Securities [Member]	Securities which will not recover in near term [Member]	Securities with the intent to sell [Member]
													Asset-backed Securities [Member]	Asset-backed Securities [Member]	Commercial Mortgage-backed Securities (CMBS) [Member]	Commercial Mortgage-backed Securities (CMBS) [Member]	Residential Mortgage Backed Securities (RMBS) [Member]	Residential Mortgage Backed Securities (RMBS) [Member]		Asset-backed Securities [Member]	Equity Securities [Member]	Equity Securities [Member]
OTTI Losses Gross	$680	$921	$3,107	$1,218	$680	$2,389	$1,326	$2,560	$1,847	($1,468)	$1,304	($1,342)	$36	$98	($1,504)	($1,396)	($22)	($44)	($44)	($44)	'	'
Other-than-temporary impairments on fixed maturity securities recognized in other comprehensive income	0	-2,023	-77	-2,241	0	0	0	0	0	-2,023	-30	-2,241	0	0	-2,023	-2,023	-30	-218	-47	-47	'	'
OTTI Losses Recognized in Earnings	$680	$2,944	$3,184	$3,459	$680	$2,389	$1,326	$2,560	$1,847	$555	$1,334	$899	$36	$98	$519	$627	$8	$174	$3	$3	$700	$600

Investments_Gross_Credit_Loss_

Investments (Gross Credit Loss Impairments of Fixed Maturity Securities for Which a Portion of the OTTI Charge was Recognized in OCI) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Investments [Abstract]	'	'	'	'
Balance, beginning of period	$7,488	$6,775	$7,477	$6,602
Addition for the amount related to credit loss for which an OTTI was not previously recognized	0	0	0	0
Reductions for securities sold during the period	0	0	0	0
Reductions for securities for which the amount previously recognized in OCI was recognized in earnings because of intention or potential requirement to sell before recovery of amortized cost	0	0	0	0
Reductions for securities for which the entire amount previously recognized in OCI was recognized in earnings due to a decrease in cash flows expected	0	0	0	0
Additional increases to the amount related to credit loss for which an OTTI was previously recognized	0	519	11	692
Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	0	0	0	0
Balance, end of period	$7,488	$7,294	$7,488	$7,294

Investments_Components_Of_Net_

Investments (Components Of Net Realized Gains, Excluding OTTI Charges) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
HTM fixed maturity securities Gains	$32,000	$40,000	$35,000	$195,000
HTM fixed maturity securities Losses	-37,000	-90,000	-86,000	-196,000
Short-term investments Losses	0	0	0	-2,000
Other investments realized gains	0	0	0	1,000
Other Investments Losses	-80,000	0	-940,000	0
Total other net realized investment gains (losses)	14,111,000	1,856,000	25,124,000	6,907,000
Total OTTI charges recognized in earnings	-680,000	-2,944,000	-3,184,000	-3,459,000
Total net realized gains (losses)	13,431,000	-1,088,000	21,940,000	3,448,000
Proceeds From Sale Of Available For Sale Securities	67,200,000	55,000,000	116,300,000	150,900,000
Fixed Maturity Securities [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
AFS securities Gains	662,000	2,168,000	2,580,000	2,941,000
AFS securities losses	-31,000	-262,000	-330,000	-379,000
Proceeds Due To Rebalancing Of Equity Securities Portfolio [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Total net realized gains (losses)	13,500,000	'	19,100,000	4,300,000
Realized Gain on Sale of Private Equity Security [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Total net realized gains (losses)	'	'	4,700,000	'
Equity Securities [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
AFS securities Gains	13,801,000	0	24,272,000	4,775,000
AFS securities losses	($236,000)	$0	($407,000)	($428,000)

Fair_Value_Measurements_Carryi

Fair Value Measurements (Carrying Value and Estimated Fair Value of Financial Instruments) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Held-to-maturity Securities	$421,962	$554,069
Available-for-sale Secuities	3,633,432	3,296,013
Equity securities, AFS	180,506	151,382
Short-term investments	172,087	214,479
Notes payable	392,407	307,387
Carrying Amount [Member]	'	'
Held-to-maturity Securities	421,962	554,069
Available-for-sale Secuities	3,633,432	3,296,013
Equity securities, AFS	180,506	151,382
Short-term investments	172,087	214,479
Receivable for proceeds related to sale of Selective HR	0	2,705
Notes payable	392,407	307,387
Carrying Amount [Member] | Two Point Ninety Percent Borrowing From Federal Home Loan Bank [Member]	'	'
Notes payable	13,000	13,000
Carrying Amount [Member] | One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member]	'	'
Notes payable	45,000	45,000
Carrying Amount [Member] | Seven Point Fifty Percent Junior Notes [Member]	'	'
Notes payable	0	100,000
Carrying Amount [Member] | Six Point Seventy Percent Senior Notes [Member]	'	'
Notes payable	99,492	99,475
Carrying Amount [Member] | Seven Point Twenty Five Percent Senior Notes [Member]	'	'
Notes payable	49,915	49,912
Carrying Amount [Member] | Five Point Eight Hundred Seventy Five Senior Notes [Member]	'	'
Notes payable	185,000	0
Fair Value [Member]	'	'
Held-to-maturity Securities	448,529	594,661
Available-for-sale Secuities	3,633,432	3,296,013
Equity securities, AFS	180,506	151,382
Short-term investments	172,087	214,479
Receivable for proceeds related to sale of Selective HR	0	2,705
Notes payable	364,171	321,061
Fair Value [Member] | Two Point Ninety Percent Borrowing From Federal Home Loan Bank [Member]	'	'
Notes payable	13,392	13,595
Fair Value [Member] | One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member]	'	'
Notes payable	45,171	45,590
Fair Value [Member] | Seven Point Fifty Percent Junior Notes [Member]	'	'
Notes payable	0	101,480
Fair Value [Member] | Six Point Seventy Percent Senior Notes [Member]	'	'
Notes payable	100,200	107,707
Fair Value [Member] | Seven Point Twenty Five Percent Senior Notes [Member]	'	'
Notes payable	51,858	52,689
Fair Value [Member] | Five Point Eight Hundred Seventy Five Senior Notes [Member]	'	'
Notes payable	$153,550	$0

Fair_Value_Measurements_Quanti

Fair Value Measurements (Quantitative Disclosures of Fair Value Assets) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Available-for-sale Secuities	$3,633,432		$3,296,013
Equity securities, AFS	180,506		151,382
Short-term investments	172,087		214,479
Fair Value [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	3,633,432		3,296,013
Equity securities, AFS	180,506		151,382
Short-term investments	172,087		214,479
Receivable for proceeds related to sale of Selective HR	'		2,705
Total assets	3,986,025		3,664,579
Fair Value [Member] | US Government and Government Agencies and Authorities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	180,786		259,092
Fair Value [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	29,709		30,229
Fair Value [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	929,498		818,024
Fair Value [Member] | Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	1,663,151		1,450,247
Fair Value [Member] | Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	150,766		128,640
Fair Value [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	151,948		137,119
Fair Value [Member] | Residential Mortgage Backed Securities (RMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	527,574		472,662
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	50,871	[1]	115,861	[1]
Equity securities, AFS	177,606	[1]	147,775	[1]
Short-term investments	172,087	[1]	214,479	[1]
Receivable for proceeds related to sale of Selective HR	'		0	[1]
Total assets	400,564	[1]	478,115	[1]
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | US Government and Government Agencies and Authorities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	50,871	[1]	115,861	[1]
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	0	[1]	0	[1]
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	0	[1]	0	[1]
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	0	[1]	0	[1]
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	0	[1]	0	[1]
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	0	[1]	0	[1]
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Residential Mortgage Backed Securities (RMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	0	[1]	0	[1]
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	3,574,990	[1]	3,144,187	[1]
Equity securities, AFS	0	[1]	0	[1]
Short-term investments	0	[1]	0	[1]
Receivable for proceeds related to sale of Selective HR	'		0	[1]
Total assets	3,574,990	[1]	3,144,187	[1]
Significant Other Observable Inputs (Level 2) [Member] | US Government and Government Agencies and Authorities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	129,915	[1]	123,442	[1]
Significant Other Observable Inputs (Level 2) [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	29,709	[1]	30,229	[1]
Significant Other Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	929,498	[1]	818,024	[1]
Significant Other Observable Inputs (Level 2) [Member] | Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	1,663,151	[1]	1,447,301	[1]
Significant Other Observable Inputs (Level 2) [Member] | Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	144,804	[1]	122,572	[1]
Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	150,339	[1]	129,957	[1]
Significant Other Observable Inputs (Level 2) [Member] | Residential Mortgage Backed Securities (RMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	527,574	[1]	472,662	[1]
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	7,571		35,965
Equity securities, AFS	2,900		3,607
Short-term investments	0		0
Receivable for proceeds related to sale of Selective HR	'		2,705
Total assets	10,471		42,277
Significant Unobservable Inputs (Level 3) [Member] | US Government and Government Agencies and Authorities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	0		19,789
Significant Unobservable Inputs (Level 3) [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	0		0
Significant Unobservable Inputs (Level 3) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	0		0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	0		2,946
Significant Unobservable Inputs (Level 3) [Member] | Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	5,962		6,068
Significant Unobservable Inputs (Level 3) [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	1,609		7,162
Significant Unobservable Inputs (Level 3) [Member] | Residential Mortgage Backed Securities (RMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Secuities	$0		$0
[1]	1 There were no transfers of securities between Level 1 and Level 2.

Fair_Value_Measurements_Change

Fair Value Measurements (Changes in Fair Value of Securities Using Level 3 Inputs) (Details) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2013		Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'
Fair value, Beginning balance	$42,277,000		$27,910,000
Total net (losses) gains for the period included in OCI	3,966,000	[1]	1,089,000	[2]
Total net (losses) gains for the period included in net income	-1,202,000	[3],[4]	0	[5],[6]
Purchases	0		12,911,000
Sales	0		0
Issuances	0		0
Settlements	-3,843,000		-3,742,000
Transfers into Level 3	0		12,642,000
Transfers out of Level 3	-30,727,000		-8,533,000
Fair value, Ending balance	10,471,000		42,277,000
Receivable amount related to sale of subsidiary	1,000,000		'
Equity Securities [Member]	'		'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'
Fair value, Beginning balance	3,607,000		0
Total net (losses) gains for the period included in OCI	3,935,000	[1]	0	[2]
Total net (losses) gains for the period included in net income	0	[3],[4]	0	[5],[6]
Purchases	0		0
Sales	0		0
Issuances	0		0
Settlements	0		0
Transfers into Level 3	0		3,607,000
Transfers out of Level 3	-4,642,000		0
Fair value, Ending balance	2,900,000		3,607,000
AFS Fixed Maturity Securities [Member]	'		'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'
Fair value, Ending balance	7,600,000		36,000,000
AFS Fixed Maturity Securities [Member] | U.S. Government and Government Agencies [Member]	'		'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'
Fair value, Beginning balance	19,789,000		21,741,000
Total net (losses) gains for the period included in OCI	-537,000	[1]	-22,000	[2]
Total net (losses) gains for the period included in net income	-76,000	[3],[4]	-193,000	[5],[6]
Purchases	0		0
Sales	0		0
Issuances	0		0
Settlements	-1,847,000		-1,737,000
Transfers into Level 3	0		0
Transfers out of Level 3	-17,329,000		0
Fair value, Ending balance	0		19,789,000
AFS Fixed Maturity Securities [Member] | Corporate Securities [Member]	'		'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'
Fair value, Beginning balance	2,946,000		2,603,000
Total net (losses) gains for the period included in OCI	-7,000	[1]	185,000	[2]
Total net (losses) gains for the period included in net income	0	[3],[4]	0	[5],[6]
Purchases	0		0
Sales	0		0
Issuances	0		0
Settlements	-168,000		-630,000
Transfers into Level 3	0		788,000
Transfers out of Level 3	-2,771,000		0
Fair value, Ending balance	0		2,946,000
AFS Fixed Maturity Securities [Member] | Asset-backed Securities [Member]	'		'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'
Fair value, Beginning balance	6,068,000		0
Total net (losses) gains for the period included in OCI	-106,000	[1]	68,000	[2]
Total net (losses) gains for the period included in net income	0	[3],[4]	0	[5],[6]
Purchases	0		7,300,000
Sales	0		0
Issuances	0		0
Settlements	0		0
Transfers into Level 3	0		0
Transfers out of Level 3	0		-1,300,000
Fair value, Ending balance	5,962,000		6,068,000
AFS Fixed Maturity Securities [Member] | Commercial Mortgage-backed Securities (CMBS) [Member]	'		'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'
Fair value, Beginning balance	7,162,000		354,000
Total net (losses) gains for the period included in OCI	681,000	[1]	858,000	[2]
Total net (losses) gains for the period included in net income	354,000	[3],[4]	-51,000	[5],[6]
Purchases	0		5,611,000
Sales	0		0
Issuances	0		0
Settlements	-1,603,000		-624,000
Transfers into Level 3	0		8,247,000
Transfers out of Level 3	-4,985,000		-7,233,000
Fair value, Ending balance	1,609,000		7,162,000
Receivable For Proceeds From Divestiture Of Business [Member]	'		'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'
Fair value, Beginning balance	2,705,000		3,212,000
Total net (losses) gains for the period included in OCI	0	[1]	0	[2]
Total net (losses) gains for the period included in net income	-1,480,000	[3],[4]	244,000	[5],[6]
Purchases	0		0
Sales	0		0
Issuances	0		0
Settlements	-225,000		-751,000
Transfers into Level 3	0		0
Transfers out of Level 3	-1,000,000		0
Fair value, Ending balance	0		2,705,000
Fair Value, Inputs, Level 3 [Member] | AFS Fixed Maturity Securities [Member]	'		'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'		'
Transfers into Level 3	'		9,000,000
Transfers out of Level 3	$25,100,000		'
[1]	Amounts are reported in “Unrealized holding gains (losses) arising during period” on the Unaudited Consolidated Statements of Comprehensive Income.
[2]	Amounts are reported in “Unrealized holding gains arising during period” on the Consolidated Statements of Comprehensive Income in our 2012 Annual Report.
[3]	Amounts are reported in “Net realized gains (losses)” for realized gains and “Net investment income earned” for amortization of securities on the Unaudited Consolidated Statements of Income.
[4]	For the receivable related to the sale of Selective HR, amounts in “Loss on disposal of discontinued operations, net of tax” relate to an impairment charge and amounts in “Other income” relate to interest accretion on the Unaudited Consolidated Statements of Income.
[5]	Amounts are reported in “Net realized gains (losses)” for realized gains and losses and “Net investment income earned” for amortization for the CMBS securities on the Consolidated Statements of Income in our 2012 Annual Report.
[6]	Amounts are reported in “Other income” for the receivable related to the sale of Selective HR on the Consolidated Statements of Income in our 2012 Annual Report and are related to interest accretion on the receivable.

Fair_Value_Measurements_Quanti1

Fair Value Measurements (Quantitative Information of Our Financial Assets and Liabilities That Were Disclosed at Fair Value) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	$421,962	$554,069
Notes payable	392,407	307,387
Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	448,529	594,661
Notes payable	364,171	321,061
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	0	0
Notes payable	153,550	209,187
Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	447,472	588,430
Notes payable	210,621	111,874
Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	1,057	6,231
Notes payable	0	0
Foreign Government [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	5,565	5,871
Foreign Government [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	0	0
Foreign Government [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	5,565	5,871
Foreign Government [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	0	0
Obligations of States and Political Subdivisions [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	395,643	526,922
Obligations of States and Political Subdivisions [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	0	0
Obligations of States and Political Subdivisions [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	395,643	526,922
Obligations of States and Political Subdivisions [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	0	0
Corporate Securities [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	31,777	42,121
Corporate Securities [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	0	0
Corporate Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	31,777	37,289
Corporate Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	0	4,832
Asset-backed Securities [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	5,911	7,097
Asset-backed Securities [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	0	0
Asset-backed Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	4,854	5,698
Asset-backed Securities [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	1,057	1,399
Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	9,633	12,650
Commercial Mortgage-backed Securities (CMBS) [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	0	0
Commercial Mortgage-backed Securities (CMBS) [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	9,633	12,650
Commercial Mortgage-backed Securities (CMBS) [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	0	0
Two Point Ninety Percent Borrowing From Federal Home Loan Bank [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	13,392	13,595
Two Point Ninety Percent Borrowing From Federal Home Loan Bank [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	0	0
Two Point Ninety Percent Borrowing From Federal Home Loan Bank [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	13,392	13,595
Two Point Ninety Percent Borrowing From Federal Home Loan Bank [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	0	0
One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	45,171	45,590
One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	0	0
One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	45,171	45,590
One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	0	0
Seven Point Fifty Percent Junior Notes [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	'	101,480
Seven Point Fifty Percent Junior Notes [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	'	101,480
Seven Point Fifty Percent Junior Notes [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	'	0
Seven Point Fifty Percent Junior Notes [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	'	0
Six Point Seventy Percent Senior Notes [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	100,200	107,707
Six Point Seventy Percent Senior Notes [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	0	107,707
Six Point Seventy Percent Senior Notes [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	100,200	0
Six Point Seventy Percent Senior Notes [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	0	0
Seven Point Twenty Five Percent Senior Notes [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	51,858	52,689
Seven Point Twenty Five Percent Senior Notes [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	0	0
Seven Point Twenty Five Percent Senior Notes [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	51,858	52,689
Seven Point Twenty Five Percent Senior Notes [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	0	0
Five Point Eight Hundred Seventy Five Senior Notes [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	153,550	'
Five Point Eight Hundred Seventy Five Senior Notes [Member] | Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	153,550	'
Five Point Eight Hundred Seventy Five Senior Notes [Member] | Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	0	'
Five Point Eight Hundred Seventy Five Senior Notes [Member] | Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	$0	'

Reinsurance_List_of_Direct_Ass

Reinsurance (List of Direct, Assumed, and Ceded Reinsurance Amounts) (Details) (USD $)	3 Months Ended		9 Months Ended				9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013
					Hurricane Sandy [Member]	Hurricane Sandy [Member]	National Flood Insurance Program [Member]
							Hurricane Sandy [Member]
Premiums written:	'	'	'	'	'	'	'
Direct	$570,849,000	$520,943,000	$1,650,855,000	$1,504,429,000	'	'	'
Assumed	22,053,000	17,976,000	34,913,000	44,712,000	'	'	'
Ceded premiums written	-100,154,000	-88,401,000	-280,719,000	-252,888,000	'	'	'
Net	492,748,000	450,518,000	1,405,049,000	1,296,253,000	'	'	'
Premiums earned:	'	'	'	'	'	'	'
Direct	518,307,000	474,055,000	1,516,454,000	1,389,373,000	'	'	'
Assumed	11,066,000	18,595,000	32,480,000	49,683,000	'	'	'
Ceded premiums earned	-91,805,000	-86,425,000	-264,174,000	-261,790,000	'	'	'
Net	437,568,000	406,225,000	1,284,760,000	1,177,266,000	'	'	'
Loss and loss expense incurred:	'	'	'	'	'	'	'
Direct	350,648,000	327,883,000	1,055,248,000	881,537,000	128,000,000	'	'
Assumed	7,264,000	13,970,000	22,758,000	35,039,000	'	'	'
Ceded loss and loss expense incurred	-74,595,000	-69,602,000	-245,246,000	-103,516,000	'	'	'
Net	283,317,000	272,251,000	832,760,000	813,060,000	'	'	'
Number of insurance subsidiaries	'	'	10	'	'	'	'
Estimated flood gross losses	'	'	'	'	1,179,000,000	1,052,000,000	'
Percentage of unpaid NFIP claims ceded by federal government	'	'	100.00%	'	'	'	'
Flood Losses Paid	'	'	'	'	'	'	$1,148,000,000

Reinsurance_Ceded_Premiums_and

Reinsurance (Ceded Premiums and Losses Related to Flood Operations) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Ceded premiums written	($100,154)	($88,401)	($280,719)	($252,888)
Ceded premiums earned	-91,805	-86,425	-264,174	-261,790
Ceded loss and loss expense incurred	-74,595	-69,602	-245,246	-103,516
National Flood Insurance Program [Member]	'	'	'	'
Ceded premiums written	-64,196	-58,923	-183,364	-171,172
Ceded premiums earned	-57,920	-53,222	-169,697	-157,895
Ceded loss and loss expense incurred	($34,879)	($32,702)	($162,780)	($24,534)

Segment_Information_Narrative_

Segment Information Narrative (Details)	9 Months Ended
	Sep. 30, 2013
Number of Operating Segments	3

Segment_Information_Revenue_Fr

Segment Information (Revenue From Continuing Operations by Segment) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	$437,568	$406,225	$1,284,760	$1,177,266
Other income	3,357	1,085	9,677	7,129
Net investment income	32,457	30,650	99,330	97,284
Net realized investment gains	13,431	-1,088	21,940	3,448
Total investment revenues	45,888	29,562	121,270	100,732
Total all segments	486,798	436,796	1,415,620	1,284,902
Total revenues	486,813	436,872	1,415,707	1,285,127
Commercial Automobile [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	79,138	72,758	230,191	214,782
Workers Compensation [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	66,510	65,592	197,449	198,064
General Liability [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	100,925	93,763	298,394	276,538
Commercial Property [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	57,004	52,197	165,356	151,945
Business Owners' Policies [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	19,629	17,749	56,794	51,872
Bonds Segment [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	4,705	4,713	14,244	14,076
Other Commercial [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	3,051	2,921	9,036	9,202
Total standard Commercial Lines [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	330,962	309,693	971,464	916,479
Personal Automobile [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	38,513	38,295	115,432	113,648
Homeowners [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	32,374	29,919	95,211	86,685
Other Personal [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	3,827	3,591	10,655	10,037
Total standard Personal Lines [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	74,714	71,805	221,298	210,370
Total Standard Insurance Operations [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	405,676	381,498	1,192,762	1,126,849
Total insurance operations revenues	409,018	382,507	1,202,352	1,133,753
Miscellaneous Income [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Other income	3,342	1,009	9,590	6,904
Excess And Surplus Operations [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Total net premiums earned	31,892	24,727	91,998	50,417
Other Income [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Other income	$15	$76	$87	$225

Segment_Information_Income_Fro

Segment Information (Income From Continuing Operations, Before Federal Income Tax) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]	'	'	'	'
Net investment income	$32,457	$30,650	$99,330	$97,284
Net realized investment gains	13,431	-1,088	21,940	3,448
Total investment revenues	45,888	29,562	121,270	100,732
Total all segments	56,039	30,423	148,065	73,268
Interest expense	-5,570	-4,725	-16,971	-14,148
General corporate and other expenses	-5,984	-5,384	-21,540	-16,307
Income from continuing operations before federal income tax	44,485	20,314	109,554	42,813
Total standard Commercial Lines [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Underwriting gain (loss), before federal income tax	8,776	-651	24,621	-14,666
Total standard Personal Lines [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Underwriting gain (loss), before federal income tax	1,362	7,220	4,360	2,903
Total Standard Insurance Operations [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Underwriting gain (loss), before federal income tax	10,138	6,569	28,981	-11,763
GAAP combined ratio	97.50%	98.30%	97.60%	101.00%
Statutory combined ratio	96.00%	96.90%	96.60%	100.10%
Excess And Surplus Operations [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Underwriting gain (loss), before federal income tax	$13	($5,708)	($2,186)	($15,701)
GAAP combined ratio	100.00%	123.10%	102.40%	131.10%
Statutory combined ratio	100.50%	121.60%	101.90%	120.30%

Indebtedness_Narrative_Details

Indebtedness (Narrative) (Details) (USD $)	Sep. 30, 2013	Mar. 31, 2013	Mar. 31, 2013	Sep. 30, 2013
In Millions, unless otherwise specified		Five Point Eight Hundred Seventy Five Senior Notes due 2043 [Member]	Redemption of Seven Point Fifty Percent Junior Notes [Member]	Line of Credit expires September 26,2017 [Member]
Aggregate principal of notes	'	$185	$100	'
Pre-tax write-off of remaining capitalized debt issuance costs	'	'	3.3	'
Bond Proceeds	'	57.1	'	'
Line of Credit Facility, Current Borrowing Capacity	'	'	'	30
Line of Credit Facility, Maximum Borrowing Capacity	'	'	'	$50
Line Of Credit Federal Home Loan Bank Maximum Borrowing Percentage Permitted	10.00%	'	'	'

Indebtedness_Covenants_in_the_

Indebtedness (Covenants in the line of credit) (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012	Sep. 30, 2012
Consolidated net worth,required	$785,000,000		'	'
Consolidated net worth, actual	1,124,209,000		1,090,592,000	1,124,378,000
Statutory Surplus, required	750,000,000		'	'
Staturtory Surplus, actual	$1,194,797,000		'	'
Debt-to-capitalization ratio,required	35.00%	[1]	'	'
Debt-to-capitalization ratio,actual	26.00%	[1]	'	'
[1]	Calculated in accordance with the Line of Credit agreement.

Retirement_Plans_Funded_Status

Retirement Plans (Funded Status of Retirement Income Plan) (Details) (USD $)	Apr. 05, 2013	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified		Retirement Income Plan [Member]	Retirement Income Plan [Member]	Retirement Income Plan [Member]	Retirement Income Plan [Member]	Retirement Income Plan [Member]	Retirement Income Plan [Member]	Retirement Income Plan [Member]
							Funded Status of Retirement Income Plan [Member]	Funded Status of Retirement Income Plan [Member]
Enhanced company contribtion to the Retirement Savings Plan	4.00%	'	'	'	'	'	'	'
Change In Benefit Obligation [Abstract]	'	'	'	'	'	'	'	'
Benefit Obligation, beginning of year	'	'	'	'	'	'	$302,647	$254,009
Service cost	'	1,857	2,154	6,163	6,462	'	2,449	8,091
Interest cost	'	3,053	3,230	9,407	9,690	'	3,303	12,981
Actuarial (gain) losses	'	'	'	'	'	'	-11,485	33,596
Benefits paid	'	'	'	'	'	'	-1,598	-6,030
Impact of curtailment	'	'	'	'	'	'	-29,603	0
Benefit Obligation, end of year	'	'	'	'	'	'	265,713	302,647
Change In Fair Value Of Assets Abstract	'	'	'	'	'	'	'	'
Fair Value of assets, beginning of year	'	'	'	'	'	'	207,150	182,614
Actual return on plan assets, net of expenses	'	'	'	'	'	'	6,760	21,896
Contributions by the employer to funded plans	'	'	'	'	'	'	2,650	8,550
Contributions by the employer to unfunded plans	'	'	'	'	'	'	30	120
Benefits paid fair value	'	'	'	'	'	'	-1,598	-6,030
Fair value of assets, end of period	'	'	'	'	'	'	214,992	207,150
Funded Status	'	'	'	'	'	'	-50,721	-95,497
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]	'	'	'	'	'	'	'	'
Liabilities	'	-50,721	'	-50,721	'	-95,497	'	'
Net pension liability, end of period	'	-50,721	'	-50,721	'	-95,497	'	'
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax [Abstract]	'	'	'	'	'	'	'	'
Prior serrvice cost	'	0	'	0	'	26	'	'
Net actuarial loss	'	57,543	'	57,543	'	103,365	'	'
Total	'	57,543	'	57,543	'	103,391	'	'
Accumulated benefit obligation	'	$257,412	'	$257,412	'	$265,899	'	'
Weighted-Average Assumptions [Abstract]	'	'	'	'	'	'	'	'
Discount Rate	'	4.66%	'	4.66%	'	4.42%	'	'
Rate of Compensation Increase	'	4.00%	'	4.00%	'	4.00%	'	'

Retirement_Plans_Components_of

Retirement Plans (Components of Net Periodic Benefit Cost and Other Amount Recognized in Other Comprehensive Income) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Curtailment expense	'	'	$16,000	$0
Reversal of amortization of net actuarial loss	790,000	1,391,000	3,419,000	4,172,000
Prior service cost	'	38,000	10,000	113,000
Retirement Income Plan [Member]	'	'	'	'
Service cost	1,857,000	2,154,000	6,163,000	6,462,000
Interest cost	3,053,000	3,230,000	9,407,000	9,690,000
Expected return on plan assets	-3,986,000	-3,547,000	-11,819,000	-10,641,000
Amortization of unrecognized prior service cost	0	38,000	10,000	113,000
Amortization of unrecognized net actuarial loss	772,000	1,383,000	3,366,000	4,149,000
Curtailment expense	'	'	16,000	0
Total net periodic cost	1,696,000	3,258,000	7,143,000	9,773,000
Net actuarial gain	'	'	-44,000,000	0
Reversal of amortization of net actuarial loss	-772,000	-1,383,000	-3,366,000	-4,149,000
Prior service cost	0	-38,000	-10,000	-113,000
Curtailment expense	'	'	-16,000	0
Total recognized in OCI	-772,000	-1,421,000	-47,392,000	-4,262,000
Total recognized in net periodic benefit cost and OCI	924,000	1,837,000	-40,249,000	5,511,000
Estimated net actuarial loss that will be amortized from AOCI into net periodic benefit cost	'	'	4,100,000	'
Retirement Life Plan [Member]	'	'	'	'
Service cost	0	0	0	0
Interest cost	69,000	73,000	208,000	221,000
Expected return on plan assets	0	0	0	0
Amortization of unrecognized prior service cost	0	0	0	0
Amortization of unrecognized net actuarial loss	18,000	8,000	53,000	23,000
Curtailment expense	'	'	0	0
Total net periodic cost	87,000	81,000	261,000	244,000
Net actuarial gain	'	'	0	0
Reversal of amortization of net actuarial loss	-18,000	-8,000	-53,000	-23,000
Prior service cost	0	0	0	0
Curtailment expense	'	'	0	0
Total recognized in OCI	-18,000	-8,000	-53,000	-23,000
Total recognized in net periodic benefit cost and OCI	$69,000	$73,000	$208,000	$221,000

Retirement_Plans_WeightedAvera

Retirement Plans (Weighted-Average Expense Assumptions) (Details)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Retirement Income Plan [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Discount rate	4.66%	5.16%
Expected return on plan assets	7.40%	7.75%
Rate of compensation increase	4.00%	4.00%
Retirement Life Plan [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Discount rate	4.42%	5.16%
Expected return on plan assets	0.00%	0.00%
Rate of compensation increase	0.00%	0.00%

Retirement_Plans_Retirement_Pl

Retirement Plans Retirement Plans (Benefit Payments) (Details) (Retirement Income Plan [Member], USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Retirement Income Plan [Member]	'
2013	$7,586
2014	8,384
2015	9,148
2016	9,942
2017	10,810
2018-2022	$67,447

Comprehensive_Income_Component

Comprehensive Income (Components of Comprehensive Income-Gross and Net of Tax) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income, Gross	$44,485	$20,314	$109,554	$42,813
Net Income, Gross (Including discontinued operations)	'	'	108,019	'
Unrealized holding gains (losses) during the period, Gross	9,820	36,620	-77,810	64,273
Non-credit portion of other-than-temporary impairment losses recognized in other comprehensive income, Gross	'	2,023	77	2,241
HTM securties, Gross	-472	-336	-1,803	-1,901
Realized (gains) losses on AFS securities, Gross	-13,516	1,037	-24,780	-3,451
Net unrealized gains (losses), Gross	-4,167	39,353	-104,302	61,434
Amount reclassified into Net Income: Net actuarial loss, Gross	790	1,391	3,419	4,172
Amount reclassified into Net Income: Prior service cost, Gross	'	38	10	113
Amount reclassified into Net Income: Curtailment expense, Gross	'	'	16	'
Defined pension and other post-retirement benefit plans, gross	790	1,429	47,445	4,285
Comprehensive income, Gross	41,108	61,096	51,162	108,532
Net income, Tax	11,832	2,040	27,474	6,158
Net Income, tax (Including discontinued operations)	'	'	26,936	'
Unrealized holding gains (losses) during the period, Tax	3,437	12,817	-27,234	22,496
Non-credit portion of other-than-temporary impairment losses recognized in other comprehensive income, Tax	'	708	27	784
HTM securities, Tax	-165	-117	-631	-665
Realized (gains) losses on AFS securities, Tax	-4,731	363	-8,673	-1,208
Net unrealized gains (losses), Tax	-1,459	13,774	-36,506	21,502
Amount reclassified into Net Income: Net actuarial loss, Tax	277	487	1,197	1,460
Amount reclassified into Net Income: Prior service cost, Tax	'	14	4	40
Amount reclassified into Net Income: Curtailment expense, tax	'	'	5	'
Defined pension and other post-retirement benefit plans, tax	277	501	16,606	1,500
Comprehensive income, Tax	10,650	16,315	7,036	29,160
Net income	32,653	18,274	81,083	36,655
Unrealized holding gains (losses) during period	6,383	23,803	-50,576	41,777
Non-credit portion of other-than-temporary impairments recognized in other comprehensive income	0	1,315	50	1,457
HTM Securities	-307	-219	-1,172	-1,236
Realized (gains) losses on available for sale securities	-8,785	674	-16,107	-2,243
Net unrealized (losses) gains on Investment Securities	-2,708	25,579	-67,796	39,932
Amount reclassified into Net Income: Net actuarial loss	513	904	2,222	2,712
Amount reclassified into Net Income: Prior service cost	0	24	6	73
Amount reclassified into Net Income: Curtailment expense	0	0	11	0
Total defined benefit pension and post-retirement plans	513	928	30,839	2,785
Comprehensive income	30,458	44,781	44,126	79,372
Accumulated Other-than-Temporary Impairment [Member]	'	'	'	'
Non-credit OTTI, Gross	1	9	14	272
Non-credit OTTI, Tax	0	3	5	95
Amounts reclassified from AOCI	1	6	9	177
Other Comprehensive Income (Loss), Net of Tax	'	'	59	'
Accumulated other comprehensive income [Member]	'	'	'	'
Other comprehensive loss, Gross	-3,377	40,782	-56,857	65,719
Other comprehensive income (loss), Tax	-1,182	14,275	-19,900	23,002
Amounts reclassified from AOCI	'	'	-15,031	'
Other Comprehensive Income (Loss), Net of Tax	-2,195	26,507	-36,957	42,717
Accumulated Defined Benefit Plans Adjustment [Member]	'	'	'	'
Net actuarial gain (loss), Gross	'	'	44,000	'
Net actuarial gains (losses),Tax	'	'	15,400	'
Net actuarial gain	0	0	28,600	0
Total defined benefit pension and post-retirement plans	'	'	$2,239	'

Comprehensive_Income_Component1

Comprehensive Income (Components of Accumulated Other Comprehensive Income) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Beginning Balance,December 31, 2012	'	'	$54,040	'
Amounts reclassified from AOCI, HTM Related	-307	-219	-1,172	-1,236
Amounts reclassified from AOCI, All Other	-8,785	674	-16,107	-2,243
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	513	928	30,839	2,785
Ending Balance, September 30, 2013	17,083	'	17,083	'
Available-for-sale Securities [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Beginning Balance,December 31, 2012	'	'	121,391	'
OCI before reclassifications	'	'	-50,473	'
Other comprehensive (loss) income	'	'	-66,580	'
Ending Balance, September 30, 2013	54,811	'	54,811	'
Investments [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Beginning Balance,December 31, 2012	'	'	122,327	'
OCI before reclassifications	'	'	-50,526	'
Amounts reclassified from AOCI	'	'	-17,270	'
Other comprehensive (loss) income	'	'	-67,796	'
Ending Balance, September 30, 2013	54,531	'	54,531	'
Accumulated Other-than-Temporary Impairment [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Beginning Balance,December 31, 2012	'	'	-1,658	'
OCI before reclassifications	'	'	50	'
Amounts reclassified from AOCI	1	6	9	177
Other comprehensive (loss) income	'	'	59	'
Ending Balance, September 30, 2013	-1,599	'	-1,599	'
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Held To Maturity Fixed Maturity Securities [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Beginning Balance,December 31, 2012	'	'	2,594	'
OCI before reclassifications	'	'	-103	'
Other comprehensive (loss) income	'	'	-1,275	'
Ending Balance, September 30, 2013	1,319	'	1,319	'
Accumulated Defined Benefit Plans Adjustment [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Beginning Balance,December 31, 2012	'	'	-68,287	'
OCI before reclassifications, Defined Benefit Pension and Post Retirement Plans	0	0	28,600	0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	'	'	2,239	'
Ending Balance, September 30, 2013	-37,448	'	-37,448	'
Accumulated other comprehensive income [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Beginning Balance,December 31, 2012	'	'	54,040	'
OCI before reclassifications	'	'	-21,926	'
Amounts reclassified from AOCI	'	'	-15,031	'
Other comprehensive (loss) income	-2,195	26,507	-36,957	42,717
Ending Balance, September 30, 2013	$17,083	'	$17,083	'

Comprehensive_Income_Reclassif

Comprehensive Income (Reclassification out of AOCI) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Total HTM Related, Tax	($165)	($117)	($631)	($665)
Amounts reclassified from AOCI, HTM Related	-307	-219	-1,172	-1,236
Total unrealized gains and losses on AFS, Gross	-13,516	1,037	-24,780	-3,451
Total unrealized gains and losses on AFS, Tax	-4,731	363	-8,673	-1,208
Realized (gains) losses on available for sale securities	-8,785	674	-16,107	-2,243
Amount reclassified into Net Income: Net actuarial loss, Gross	790	1,391	3,419	4,172
Prior service cost	'	38	10	113
Curtailment expense	'	'	16	'
Total defined benefit pension and post-retirement life, Gross	790	1,429	47,445	4,285
Total defined benefit pension and post-retirement life,Tax	277	501	16,606	1,500
Total defined benefit pension and post-retirement plans	513	928	30,839	2,785
Accumulated Other-than-Temporary Impairment [Member]	'	'	'	'
Amounts reclassified from AOCI	1	6	9	177
Net Realized Investment Gains [Member]	'	'	'	'
Unrealized gains and losses on HTM disposals	-19	'	-170	'
Total unrealized gains and losses on AFS, Gross	-13,516	'	-24,780	'
Net Investment Income Earned [Member]	'	'	'	'
HTM Related, Gross	-453	'	-1,633	'
Net Investment Income Earned [Member] | Accumulated Other-than-Temporary Impairment [Member]	'	'	'	'
Amortization of non-credit OTTI losses on HTM securities	1	'	14	'
Income From Continuing Operations Before Federal Income Tax [Member]	'	'	'	'
HTM Related, Gross	-472	'	-1,803	'
Total unrealized gains and losses on AFS, Gross	-13,516	'	-24,780	'
Amount reclassified into Net Income: Net actuarial loss, Gross	790	'	3,419	'
Prior service cost	0	'	10	'
Curtailment expense	0	'	16	'
Total defined benefit pension and post-retirement life, Gross	790	'	3,445	'
Income From Continuing Operations Before Federal Income Tax [Member] | Accumulated Other-than-Temporary Impairment [Member]	'	'	'	'
Amortization of non-credit OTTI losses on HTM securities	1	'	14	'
Total Federal Income Tax Expense [Member]	'	'	'	'
Total HTM Related, Tax	165	'	631	'
Total unrealized gains and losses on AFS, Tax	4,731	'	8,673	'
Total defined benefit pension and post-retirement life,Tax	-277	'	-1,206	'
Total Federal Income Tax Expense [Member] | Accumulated Other-than-Temporary Impairment [Member]	'	'	'	'
Amortization of non-credit OTTI losses on HTM securities, tax	0	'	-5	'
Net Income Financial Statement [Member]	'	'	'	'
Amounts reclassified from AOCI	-8,578	'	-15,031	'
Amounts reclassified from AOCI, HTM Related	-307	'	-1,172	'
Realized (gains) losses on available for sale securities	-8,785	'	-16,107	'
Net Income Financial Statement [Member] | Accumulated Other-than-Temporary Impairment [Member]	'	'	'	'
Amounts reclassified from AOCI	1	'	9	'
Net Income Financial Statement [Member] | Accumulated Defined Benefit Plans Adjustment [Member]	'	'	'	'
Total defined benefit pension and post-retirement plans	513	'	2,239	'
Loss and loss expense incurred [Member]	'	'	'	'
Amount reclassified into Net Income: Net actuarial loss, Gross	159	'	717	'
Prior service cost	0	'	7	'
Policy acquisition costs [Member]	'	'	'	'
Amount reclassified into Net Income: Net actuarial loss, Gross	631	'	2,702	'
Prior service cost	0	'	3	'
Curtailment expense	$0	'	$16	'

Discontinued_Operations_Narrat

Discontinued Operations (Narrative) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2013	Dec. 31, 2009
Percentage Of Interest Sold In Subsidiary	'	'	100.00%
Receivable amount related to sale of subsidiary	'	$1	'
Discontinued gain (loss) from disposal of discontinued operation, before federal income tax	($1.50)	'	'

Commitments_and_Contingencies_

Commitments and Contingencies (Narrative) (Details) (Other Investments [Member], USD $)	Sep. 30, 2013
In Thousands, unless otherwise specified
Other Investments [Member]	'
Remaining Commitment	$58,935