Selective Insurance (SIGI) 10-Q 24 Apr 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014
Document Information [Line Items]	'
Document Type	'10-Q
Amendment Flag	'false
Document Period End Date	31-Mar-14
Document Fiscal Year Focus	'2014
Document Fiscal Period Focus	'Q1
Entity Registrant Name	'SELECTIVE INSURANCE GROUP INC
Entity Central Index Key	'0000230557
Current Fiscal Year End Date	'--12-31
Entity Filer Category	'Large Accelerated Filer
Entity Common Stock , Shares Outstanding	56,219,199

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
ASSETS	'	'
Fixed income securities, held-to-maturity – at carrying value (fair value: $403,536 – 2014; $416,981 – 2013)	$382,056	$392,879
Fixed income securities, available-for-sale – at fair value (amortized cost: $3,784,456– 2014; $3,675,977 – 2013)	3,815,853	3,715,536
Equity securities, available-for-sale – at fair value (cost: $162,370 – 2014; $155,350 – 2013)	197,687	192,771
Short-term investments (at cost which approximates fair value)	137,733	174,251
Other investments	106,720	107,875
Total investments	4,640,049	4,583,312
Cash	245	193
Interest and dividends due or accrued	36,967	37,382
Premiums receivable, net of allowance for uncollectible accounts of: $3,771 – 2014; $4,442 – 2013	553,912	524,870
Reinsurance recoverables, net	574,621	550,897
Prepaid reinsurance premiums	141,603	143,000
Current federal income tax	0	512
Deferred federal income tax	113,061	122,613
Property and equipment – at cost, net of accumulated depreciation and amortization of: $181,959 – 2014; $179,192 – 2013	53,725	50,834
Deferred policy acquisition costs	177,678	172,981
Goodwill	7,849	7,849
Other assets	70,526	75,727
Total assets	6,370,236	6,270,170
Liabilities And Stockholders' Equity	'	'
Reserve for loss and loss expenses	3,432,432	3,349,770
Unearned premiums	1,078,012	1,059,155
Notes payable	392,420	392,414
Current federal income tax	3,249	0
Accrued salaries and benefits	89,558	111,427
Other liabilities	189,034	203,476
Total liabilities	5,184,705	5,116,242
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: 99,536,697 – 2014; 99,120,235 – 2013	199,073	198,240
Additional paid-in capital	294,365	288,182
Retained earnings	1,212,577	1,202,015
Accumulated other comprehensive income	41,529	24,851
Treasury stock - at cost (shares: 43,317,498 – 2014; 43,198,622 – 2013)	-562,013	-559,360
Total stockholders' equity	1,185,531	1,153,928
Commitments and contingencies	'	'
Total liabilities and stockholders' equity	$6,370,236	$6,270,170

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Fixed income securities, held-to-maturity, fair value	$403,536	$416,981
Fixed maturity securities, available-for-sale, amortized cost	3,748,456	3,675,977
Equity securities, available-for-sale, cost	162,370	155,350
Premiums receivable, allowance for uncollectible accounts	3,771	4,442
Property and equipment, accumulated depreciation and amortization	$181,959	$179,192
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	99,536,697	99,120,235
Treasury stock, shares	43,317,498	43,198,622

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Revenues:	'	'
Net premiums earned	$456,495	$420,940
Net investment income earned	35,534	32,870
Net realized gains:	'	'
Net realized investment gains	8,181	5,304
Other-than-temporary impairments	-963	-1,919
Other-than-temporary impairments on fixed maturity securities recognized in other comprehensive income	0	-30
Total net realized gains	7,218	3,355
Other income	9,824	2,784
Total revenues	509,071	459,949
Expenses:	'	'
Loss and loss expense incurred	320,546	269,849
Policy acquisition costs	149,266	139,528
Interest expense	5,561	5,831
Other expenses	8,614	15,873
Total expenses	483,987	431,081
Income from continuing operations, before federal income tax	25,084	28,868
Federal income tax expense (benefit):	'	'
Current	6,538	7,453
Deferred	572	-890
Total federal income tax expense	7,110	6,563
Net income from continuing operations	17,974	22,305
Loss on disposal of discontinued operations, net of tax of $(538) - 2013	0	-997
Net income	$17,974	$21,308
Earnings per share:	'	'
Basic net income from continuing operations	$0.32	$0.40
Basic net loss from discontinued operations	$0	($0.02)
Basic net income	$0.32	$0.38
Diluted net income from continuing operations	$0.31	$0.40
Diluted net loss from discontinued operations	$0	($0.02)
Diluted net income	$0.31	$0.38
Dividends to stockholders	$0.13	$0.13

Consolidated_Statements_of_Inc1

Consolidated Statements of Income Parenthetical (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Tax effect of loss on disposal of discontinued operations	($538)

Consolidation_Statements_of_Co

Consolidation Statements of Comprehensive Income (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net income	$17,974	$21,308
Unrealized holding gains arising during period	21,426	2,394
Non-credit portion of other-than-temporary impairments recognized in other comprehensive income	0	20
Amount reclassified into net income: Held-to-maturity Securities	-296	-466
Realized gains on available for sale securities	-4,699	-3,884
Total unrealized gains (losses) on investment securities	16,431	-1,932
Amount reclassified into Net Income: Net actuarial loss	247	1,196
Amount reclassified into Net Income: Prior service cost	0	6
Amount reclassified into Net Income: Curtailment expense	0	11
Total defined benefit pension and post-retirement plans	247	29,813
Comprehensive income	34,652	49,189
Accumulated Defined Benefit Plans Adjustment [Member]	'	'
Net actuarial gain	0	28,600
Total defined benefit pension and post-retirement plans	247	'
Accumulated Other-than-Temporary Impairment [Member]	'	'
Amounts reclassified into Net Income: Non-credit other-than-temporary impairment	0	4
Other comprehensive income	0	'
Accumulated other comprehensive income [Member]	'	'
Amounts reclassified into Net Income: Non-credit other-than-temporary impairment	-4,748	'
Other comprehensive income	$16,678	$27,881

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, 2012	'	$196,388	$270,654	$1,125,154	$54,040	($555,644)
Dividend reinvestment plan (shares:15,283 – 2014; 17,314 - 2013)	'	35	349	'	'	'
Stock purchase and compensation plans (shares: 401,179 - 2014; 496,647 - 2013)	'	993	5,714	'	'	'
Net income	21,308	'	'	21,308	'	'
Dividends to stockholders ($0.13 per share - 2014 and 2013)	'	'	'	-7,351	'	'
Other comprehensive income	'	'	'	'	27,881	'
Acquisition of treasury stock (shares: 118,876- 2014; 146,436 - 2013)	'	'	'	'	'	-3,176
End of period at Mar. 31, 2013	1,136,345	197,416	276,717	1,139,111	81,921	-558,820
Beginning of year at Dec. 31, 2013	1,153,928	198,240	288,182	1,202,015	24,851	-559,360
Dividend reinvestment plan (shares:15,283 – 2014; 17,314 - 2013)	'	31	320	'	'	'
Stock purchase and compensation plans (shares: 401,179 - 2014; 496,647 - 2013)	'	802	5,863	'	'	'
Net income	17,974	'	'	17,974	'	'
Dividends to stockholders ($0.13 per share - 2014 and 2013)	'	'	'	-7,412	'	'
Other comprehensive income	'	'	'	'	16,678	'
Acquisition of treasury stock (shares: 118,876- 2014; 146,436 - 2013)	'	'	'	'	'	-2,653
End of period at Mar. 31, 2014	$1,185,531	$199,073	$294,365	$1,212,577	$41,529	($562,013)

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Dividend reinvestment plan, shares	15,283	17,314
Stock purchase and compensation plans, shares	401,179	496,647
Dividends to stockholders, per share	$0.13	$0.13
Acquisition of treasury stock, shares	118,876	146,436
Preferred stock, par value per share	$0	$0
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Series A Preferred Stock [Member]	'	'
Preferred stock, par value per share	$0	$0
Preferred stock, shares authorized	300,000	300,000

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flow (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Operating Activities	'	'
Net income	$17,974	$21,308
Adjustments to Reconcile Net Income to net Cash Provided by Operating Activities [Abstract]	'	'
Depreciation and amortization	10,578	13,148
Sale of renewal rights	-8,000	0
Loss on disposal of discontinued operations	0	997
Stock-based compensation expense	4,176	3,692
Undistributed (gains) losses of equity method investments	-33	426
Net realized gains	-7,218	-3,355
Retirement income plan curtailment expense	0	16
Changes in assets and liabilities:	'	'
Increase in reserve for loss and loss expenses, net of reinsurance recoverables	58,938	38,556
Increase in unearned premiums, net of prepaid reinsurance and advance premiums	19,875	30,106
Decrease in net federal income taxes	4,332	5,290
Increase in premiums receivable	-29,042	-36,202
Increase in deferred policy acquisition costs	-4,697	-2,963
Decrease in interest and dividends due or accrued	414	384
Decrease in accrued salaries and benefits	-21,869	-4,528
Decrease in accrued insurance expenses	-26,957	-12,378
Other-net	17,293	-26,357
Net adjustments	17,790	6,832
Net cash provided by operating activities	35,764	28,140
Investing Activities	'	'
Purchase of fixed income securities, available-for-sale	-182,809	-308,289
Purchase of equity securities, available-for-sale	-61,360	-2
Purchase of other investments	-4,615	-2,329
Purchase of short-term investments	-398,348	-644,274
Sale of subsidiary	0	225
Sale of fixed income securities, available-for-sale	1,302	6,851
Sale of short-term investments	434,865	695,313
Redemption and maturities of fixed income securities, held-to-maturity	9,396	28,644
Redemption and maturities of fixed income securities, available-for-sale	104,358	124,975
Sale of equity securities, available-for-sale	61,523	0
Distributions from other investments	5,704	3,447
Purchase of property and equipment	-5,699	-3,673
Sale of renewal rights	8,000	0
Net cash used in investing activities	-27,683	-99,112
Financing Activities	'	'
Dividends to stockholders	-6,948	-6,824
Acquisition of treasury stock	-2,653	-3,176
Net proceeds from stock purchase and compensation plans	1,261	1,164
Proceeds from issuance of notes payable, net of debt issuance costs	0	178,623
Repayment of notes payable	0	-100,000
Excess tax benefits from share-based payment arrangements	770	1,271
Repayments of capital lease obligations	-459	0
Net cash (used in) provided by financing activities	-8,029	71,058
Net increase in cash	52	86
Cash, beginning of year	193	210
Cash, end of period	$245	$296

Organization

Organization	3 Months Ended
	Mar. 31, 2014
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 ("NFIPs") write-your-own ("WYO") program;
	•	Our E&S Insurance Operations segment sells Commercial Lines property and casualty insurance products and services to insureds who have not obtained coverage in the standard market; and
	•	Our Investments segment, which invests the premiums collected by our Standard and E&S Insurance Operations and amounts generated through our capital management strategies, which may include the issuance of debt and equity securities.

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2014
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 2014 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 first quarters ended March 31, 2014 (“First Quarter 2014”) and March 31, 2013 (“First Quarter 2013”). 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, 2013 (“2013 Annual Report”) filed with the SEC.

Adoption_of_Accounting_Pronoun

Adoption of Accounting Pronouncements	3 Months Ended
	Mar. 31, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Adoption Of Accounting Pronouncements	'
	Adoption of Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("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 was effective for fiscal years, and interim periods within those years, beginning after December 15, 2013. The adoption of this guidance did not impact our financial condition or results of operation.
	Pronouncements to be effective in the future
	In January 2014, the FASB issued ASU 2014-01, Accounting for Investments in Qualified Affordable Housing Projects ("ASU 2014-01").  ASU 2014-01 applies to all reporting entities that invest in flow-through limited liability entities that manage or invest in affordable housing projects that qualify for a low-income housing tax credit. ASU 2014-01 permits reporting entities to make an accounting policy election to account for their investments in qualified affordable housing projects using a newly defined "proportional amortization method" if certain conditions are met. Under the proportional amortization method, an entity amortizes the initial cost of the investment in proportion to the tax credits and other tax benefits received and recognizes the net investment performance in the income statement as components of income tax expense (benefit).  For those investments in qualified affordable housing projects not accounted for using the proportional amortization method, the investment is required to be accounted for as an equity method investment or a cost method investment.
	ASU 2014-01 is effective for public business entities for annual periods and interim periods within those annual periods, beginning after December 15, 2014.  The adoption of this guidance will not have a material impact on our financial condition or results of operations.

Statements_of_Cash_Flow

Statements of Cash Flow	3 Months Ended
	Mar. 31, 2014
Supplemental Cash Flow Information [Abstract]	'
Statements of Cash Flow	'
	Statements of Cash Flow
	Cash paid during the period for interest and federal income taxes was as follows:
		Three Months ended March 31,
	($ in thousands)	2014		2013
	Cash paid during the period for:
	Interest	$	2,973	1,964
	Federal income tax	2,000		—
	Non-cash items:
	Tax-free exchange of fixed income securities, AFS	—		8,470
	Tax-free exchange of fixed income securities, HTM	15		7,168
	At March 31, 2014, included in "Other assets" on the Consolidated Balance Sheets was $6.1 million of cash received from the NFIP, which is restricted to pay flood claims under the WYO program.

Investments

Investments	3 Months Ended
	Mar. 31, 2014
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 income securities as of March 31, 2014 and December 31, 2013 were as follows:
	March 31, 2014
	($ in thousands)	Amortized			Net		Carrying			Unrecognized		Unrecognized Holding		Fair
		Cost			Unrealized Gains		Value			Holding		Losses		Value
					(Losses)					Gains
	Foreign government	$	5,292		110		5,402			150		—		5,552
	Obligations of state and political subdivisions	344,360			3,475		347,835			16,472		—		364,307
	Corporate securities	21,903			(341	)	21,562			2,902		—		24,464
	Asset-backed securities (“ABS”)	3,347			(621	)	2,726			640		—		3,366
	Commercial mortgage-backed securities (“CMBS”)	5,353			(822	)	4,531			1,316		—		5,847
	Total HTM fixed income securities	$	380,255		1,801		382,056			21,480		—		403,536
	December 31, 2013
	($ in thousands)	Amortized			Net		Carrying			Unrecognized		Unrecognized Holding		Fair
		Cost			Unrealized Gains		Value			Holding		Losses		Value
					(Losses)					Gains
	Foreign government	$	5,292		131		5,423			168		—		5,591
	Obligations of state and political subdivisions	348,109			4,013		352,122			17,634		—		369,756
	Corporate securities	28,174			(346	)	27,828			2,446		—		30,274
	ABS	3,413			(655	)	2,758			657		—		3,415
	CMBS	5,634			(886	)	4,748			3,197		—		7,945
	Total HTM fixed income securities	$	390,622		2,257		392,879			24,102		—		416,981
	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 2.2 years as of March 31, 2014.
	(b) The cost/amortized cost, unrealized gains and losses, and fair value of AFS securities as of March 31, 2014 and December 31, 2013 were as follows:
	March 31, 2014
	($ in thousands)	Cost/			Unrealized		Unrealized			Fair
		Amortized			Gains		Losses			Value
		Cost
	U.S. government and government agencies	$	161,428		10,007		(370	)		171,065
	Foreign government	31,538			912		(29	)		32,421
	Obligations of states and political subdivisions	963,237			26,617		(10,687	)		979,167
	Corporate securities	1,777,186			48,305		(9,793	)		1,815,698
	ABS	131,386			908		(360	)		131,934
	CMBS1	172,386			4,686		(2,256	)		174,816
	Residential mortgage-backed	511,295			7,210		(7,753	)		510,752
	securities (“RMBS”)2
	AFS fixed income securities	3,748,456			98,645		(31,248	)		3,815,853
	AFS equity securities	162,370			35,434		(117	)		197,687
	Total AFS securities	$	3,910,826		134,079		(31,365	)		4,013,540
	December 31, 2013
	($ in thousands)	Cost/			Unrealized		Unrealized			Fair
		Amortized			Gains		Losses			Value
		Cost
	U.S. government and government agencies	$	163,218		10,661		(504	)		173,375
	Foreign government	29,781			906		(72	)		30,615
	Obligations of states and political subdivisions	946,455			25,194		(20,025	)		951,624
	Corporate securities	1,707,928			44,004		(17,049	)		1,734,883
	ABS	140,430			934		(468	)		140,896
	CMBS1	172,288			2,462		(3,466	)		171,284
	RMBS2	515,877			7,273		(10,291	)		512,859
	AFS fixed income securities	3,675,977			91,434		(51,875	)		3,715,536
	AFS equity securities	155,350			37,517		(96	)		192,771
	Total AFS securities	$	3,831,327		128,951		(51,971	)		3,908,307
	1 CMBS includes government guaranteed agency securities with a fair value of $24.5 million at March 31, 2014 and $30.0 million at December 31, 2013.
	2 RMBS includes government guaranteed agency securities with a fair value of $48.2 million at March 31, 2014 and $55.2 million at December 31, 2013.
	Unrealized gains and losses of AFS securities represent fair value fluctuations from the later of: (i) the date a security is designated as AFS; or (ii) the date that an OTTI charge is recognized on an AFS security, through the date of the balance sheet. These unrealized gains and losses are recorded in Accumulated Other Comprehensive Income ("AOCI") on the Consolidated Balance Sheets.
	(c) The following tables summarize, for all securities in a net unrealized/unrecognized loss position at March 31, 2014 and December 31, 2013, the fair value and gross pre-tax net unrealized/unrecognized loss by asset class and by length of time those securities have been in a net loss position:
	March 31, 2014	Less than 12 months					12 months or longer
	($ in thousands)	Fair Value			Unrealized		Fair Value			Unrealized
					Losses1					Losses1
	AFS securities
	U.S. government and government agencies	$	13,119		(370	)	—			—
	Foreign government	1,753			(9	)	2,978			(20	)
Obligations of states and political subdivisions	373,064			(9,984	)	20,096			(703	)
Corporate securities	464,163			(8,636	)	17,713			(1,157	)
ABS	23,855			(360	)	—			—
CMBS	72,437			(1,962	)	7,466			(294	)
RMBS	221,314			(7,294	)	4,823			(459	)
Total fixed income securities	1,169,705			(28,615	)	53,076			(2,633	)
Equity securities	1,938			(117	)	—			—
Subtotal	$	1,171,643		(28,732	)	53,076			(2,633	)
	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	$	—		—		—			445		(19	)	18
ABS	—			—		—			2,495		(621	)	592
Subtotal	$	—		—		—			2,940		(640	)	610
Total AFS and HTM	$	1,171,643		(28,732	)	—			56,016		(3,273	)	610
December 31, 2013	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	$	16,955		(500	)	507			(4	)
Foreign government	2,029			(30	)	2,955			(42	)
Obligations of states and political subdivisions	442,531			(19,120	)	13,530			(905	)
Corporate securities	511,100			(15,911	)	14,771			(1,138	)
ABS	68,725			(468	)	—			—
CMBS	100,396			(2,950	)	6,298			(516	)
RMBS	268,943			(10,031	)	2,670			(260	)
Total fixed income securities	1,410,679			(49,010	)	40,731			(2,865	)
Equity securities	1,124			(96	)	—			—
Subtotal	$	1,411,803		(49,106	)	40,731			(2,865	)
	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	$	65		(5	)	5			441		(20	)	14
ABS	—			—		—			2,490		(655	)	621
Subtotal	65			(5	)	5			2,931		(675	)	635
Total AFS and HTM	$	1,411,868		(49,111	)	5			43,662		(3,540	)	635
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 improved by $20.6 million as of March 31, 2014 compared to December 31, 2013 as follows:
($ in thousands)
March 31, 2014					December 31, 2013
Number of	% of Market/Book	Unrealized/			Number of	% of	Unrealized/
Issues		Unrecognized Loss			Issues	Market/Book	Unrecognized
							Loss
466	80% - 99%	$	31,395		556	80% - 99%	$	51,835
—	60% - 79%	—			1	60% - 79%	176
—	40% - 59%	—			—	40% - 59%	—
—	20% - 39%	—			—	20% - 39%	—
—	0% - 19%	—			—	0% - 19%	—
		$	31,395				$	52,011
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 2013 Annual Report.
At March 31, 2014, we had 466 securities in an aggregate unrealized/unrecognized loss position of $31.4 million, $2.7 million of which have been in a loss position for more than 12 months. At December 31, 2013, we had 557 securities in an aggregate unrealized/unrecognized loss position of $52.0 million, $2.9 million of which had been in a loss position for more than 12 months. During First Quarter 2014, interest rates on the 10-year U.S. Treasury Note fell by 31 basis points. This interest rate movement had a positive impact on our fixed income securities portfolio's valuation, thus decreasing the number of securities in a loss position and the corresponding dollar amount of unrealized losses. For a discussion regarding the sensitivity of interest rate movements and the related impacts on the fixed income securities portfolio, refer to Item 7A. "Quantitative and Qualitative Disclosures About Market Risk" in our 2013 Annual Report.
We do not intend to sell any securities in an unrealized/unrecognized loss position, nor do we believe we will be required to sell these securities, and therefore we have concluded that they are temporarily impaired as of March 31, 2014. This conclusion reflects our current judgment as to the financial position and future prospects of the entity that issued the investment security and underlying collateral. If our judgment about an individual security changes in the future, we may ultimately record a credit loss after having originally concluded that one did not exist, which could have a material impact on our net income and financial position in future periods.
(d) Fixed income securities at March 31, 2014, by contractual maturity, are shown below. Mortgage-backed securities ("MBS") are included in the maturity tables using the estimated average life of each security. Expected maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations, with or without call or prepayment penalties.
Listed below are HTM fixed income securities at March 31, 2014:
($ in thousands)	Carrying Value			Fair Value
Due in one year or less	$	80,337		81,332
Due after one year through five years	270,608			287,045
Due after five years through 10 years	31,111			35,159
Total HTM fixed income securities	$	382,056		403,536
Listed below are AFS fixed income securities at March 31, 2014:
($ in thousands)	Fair Value
Due in one year or less	$	425,744
Due after one year through five years	1,991,515
Due after five years through 10 years	1,345,666
Due after 10 years	52,928
Total AFS fixed income securities	$	3,815,853
(e) The following table summarizes our other investment portfolio by strategy and the remaining commitment amount associated with each strategy:
Other Investments	Carrying Value					March 31,
						2014
($ in thousands)	March 31,			December 31,		Remaining Commitment
	2014			2013
Alternative Investments
Secondary private equity	$	23,595		25,618		6,479
Private equity	21,117			20,192		9,959
Energy/power generation	17,978			17,361		6,984
Mezzanine financing	13,831			12,738		15,038
Distressed debt	10,882			11,579		2,971
Real estate	10,728			11,698		10,178
Venture capital	7,019			7,025		350
Total alternative investments	105,150			106,211		51,959
Other securities	1,570			1,664		597
Total other investments	$	106,720		107,875		52,556
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 2013 Annual Report.
The following table sets forth gross summarized financial information for our other investments portfolio, including the portion not owned by us. The investments are 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 reports results to us on a quarter lag, the summarized financial statement information for the three-month periods ended December 31 is as follows:
Income Statement Information	Quarter ended December 31,
($ in millions)	2013			2012
Net investment income	$	65.1		204.8
Realized gains	63.3			593.4
Net change in unrealized appreciation (depreciation)	505.9			(417.5	)
Net income	$	634.3		380.7
Selective’s insurance subsidiaries’ other investments income	$	5.2		3.6
(f) At March 31, 2014, we had fixed income securities, with a carrying value of $61.8 million, that were pledged as collateral for our outstanding borrowing of $58 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 income securities portfolio.
Also at March 31, 2014, we had fixed income securities, with a carrying value of $22.3 million, and short-term investments with a carrying value of $0.2 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 income securities are included in the "Municipal," "Corporate," "U.S. government and government agencies," "RMBS," and "ABS" classifications of our AFS fixed income securities portfolio.
In addition, fixed income securities with a carrying value of $26.2 million were on deposit with various state and regulatory agencies to comply with insurance laws. We retain all rights regarding these securities, which are primarily included in the "U.S. government and government agencies" classification of our AFS fixed income securities portfolio.
(g) The components of net investment income earned for the periods indicated were as follows:
	Quarter ended March 31,
($ in thousands)	2014			2013
Fixed income securities	$	31,028		30,089
Equity securities	1,449			1,207
Short-term investments	19			52
Other investments	5,218			3,602
Investment expenses	(2,180		)	(2,080	)
Net investment income earned	$	35,534		32,870
(h) The following tables summarize OTTI by asset type for the periods indicated:
First Quarter 2014	Gross			Included in Other		Recognized in
				Comprehensive		Earnings
($ in thousands)				Income (“OCI”)
AFS securities
Equity securities	$	963		—		963
Total AFS Securities	963			—		963
OTTI losses	$	963		—		963
First Quarter 2013	Gross			Included in OCI		Recognized in Earnings
($ in thousands)
AFS fixed income securities
RMBS	$	(22	)	(30	)	8
Total AFS fixed income securities	(22		)	(30	)	8
Equity securities	217			—		217
Total AFS securities	195			(30	)	225
Other investments	1,724			—		1,724
OTTI losses	$	1,919		(30	)	1,949
The OTTI charges in First Quarter 2014 relate to equity securities for which we have the intent to sell. The majority of the OTTI charges in First Quarter 2013 related to an investment in a limited liability company within our other investments portfolio that had sustained significant losses for which we did not anticipate recovery. For a discussion of our evaluation for OTTI of fixed income 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 2013 Annual Report.
The following tables set forth, for the periods indicated, credit loss impairments on fixed income securities for which a portion of the OTTI charge was recognized in OCI, and the corresponding changes in such amounts:
	Quarter ended March 31,
($ in thousands)	2014			2013
Balance, beginning of period	$	7,488		7,477
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	—			9
Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	—			—
Balance, end of period	$	7,488		7,486
(i) The components of net realized gains, excluding OTTI charges, for the periods indicated were as follows:
	Quarter ended March 31,
($ in thousands)	2014			2013
HTM fixed income securities
Gains	$	—		—
Losses	(11		)	(37	)
AFS fixed income securities
Gains	158			951
Losses	(112		)	(253	)
AFS equity securities
Gains	8,317			5,671
Losses	(171		)	(168	)
Other investments
Gains	—			—
Losses	—			(860	)
Total other net realized investment gains	8,181			5,304
Total OTTI charges recognized in earnings	(963		)	(1,949	)
Total net realized gains	$	7,218		3,355
Realized gains and losses on the sale of investments are determined on the basis of the cost of the specific investments sold. The $8.2 million and $5.3 million in net realized gains in First Quarter 2014 and First Quarter 2013, respectively, were primarily related to the sale of AFS equity securities due to a rebalancing of our equity portfolio.
Proceeds from the sale of AFS securities were $62.8 million in First Quarter 2014 and $6.9 million in First Quarter 2013.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2014
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 March 31, 2014 and December 31, 2013:
			March 31, 2014						December 31, 2013
	($ in thousands)		Carrying Amount			Fair			Carrying Amount			Fair
						Value						Value
	Financial Assets
	Fixed income securities:
	HTM		$	382,056		403,536			392,879			416,981
	AFS		3,815,853			3,815,853			3,715,536			3,715,536
	Equity securities, AFS		197,687			197,687			192,771			192,771
	Short-term investments		137,733			137,733			174,251			174,251
	Financial Liabilities
	Notes payable:
	2.90% borrowings from FHLBI		13,000			13,243			13,000			13,319
	1.25% borrowings from FHLBI		45,000			45,226			45,000			45,259
	7.25% Senior Notes		49,917			53,065			49,916			50,887
	6.70% Senior Notes		99,503			102,810			99,498			98,247
	5.875% Senior Notes		185,000			165,316			185,000			146,298
	Total notes payable		$	392,420		379,660			392,414			354,010
	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 2013 Annual Report.
	The following tables provide quantitative disclosures of our financial assets that were measured at fair value at March 31, 2014 and December 31, 2013:
	March 31, 2014					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 3/31/2014			Liabilities (Level 1)1			(Level 2)1
	Description
	Measured on a recurring basis:
	AFS:
	U.S. government and government agencies		$	171,065		51,796			119,269			—
	Foreign government		32,421			—			32,421			—
	Obligations of states and political subdivisions		979,167			—			979,167			—
	Corporate securities		1,815,698			—			1,815,698			—
	ABS		131,934			—			131,934			—
	CMBS		174,816			—			174,816			—
	RMBS		510,752			—			510,752			—
	Total AFS fixed income securities		3,815,853			51,796			3,764,057			—
	Equity securities		197,687			194,787			—			2,900
	Total AFS Securities		4,013,540			246,583			3,764,057			2,900
	Short-term investments		137,733			137,733			—			—
	Total assets measured at fair value		$	4,151,273		384,316			3,764,057			2,900
	1	There were no transfers of securities between Level 1 and Level 2.
	December 31, 2013					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 12/31/13			(Level 1)1			(Level 2)1
	Description
	Measured on a recurring basis:
	AFS:
	U.S. government and government agencies		$	173,375		52,153			121,222			—
	Foreign government		30,615			—			30,615			—
	Obligations of states and political subdivisions		951,624			—			951,624			—
	Corporate securities		1,734,883			—			1,734,883			—
	ABS		140,896			—			140,896			—
	CMBS		171,284			—			171,284			—
	RMBS		512,859			—			512,859			—
	Total AFS fixed income securities		3,715,536			52,153			3,663,383			—
	Equity securities		192,771			189,871			—			2,900
	Total AFS Securities		3,908,307			242,024			3,663,383			2,900
	Short-term investments		174,251			174,251			—			—
	Total assets measured at fair value		$	4,082,558		416,275			3,663,383			2,900
1	There were no transfers of securities between Level 1 and Level 2.
There have been no changes in the fair value of securities measured using Level 3 prices during First Quarter 2014. The following table provides a summary of these changes during 2013:
31-Dec-13
($ in thousands)		Government			Corporate				ABS			CMBS			Equity			Receivable for			Total
																		Proceeds
																		Related to Sale
																		of Selective HR Solutions ("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		)		(74		)	772			3,935			—			4,089
Net income2,3		(76		)	—				—			361			—			(1,480		)	(1,195		)
Purchases		—			—				—			—			—			—			—
Sales		—			—				—			—			—			—			—
Issuances		—			—				—			—			—			—			—
Settlements		(1,847		)	(168		)		—			(2,420		)	—			(225		)	(4,660		)
Transfers into Level 3		—			—				—			—			—			—			—
Transfers out of Level 3		(17,329		)	(2,771		)		(5,994		)	(5,875		)	(4,642		)	(1,000		)	(37,611		)
Fair value, December 31, 2013		$	—		$	—			$	—		$	—		$	2,900		$	—		$	2,900
1 Amounts are reported in “Unrealized holding (losses) gains arising during period” on the Consolidated Statements of Comprehensive Income in our 2013 Annual Report.
2 Amounts are reported in “Net realized gains” for realized gains and losses and “Net investment income earned” for amortization of securities on the Consolidated Statements of Income in our 2013 Annual Report.
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 Consolidated Statements of Income in our 2013 Annual Report.
As discussed in Note 2. "Summary of Significant Accounting Policies," in Item 8. "Financial Statements and Supplementary Data." in our 2013 Annual Report, the fair value of our Level 3 fixed income securities is typically obtained through non-binding broker quotes based on unobservable inputs, which we review for reasonableness. There were no fixed income securities measured using Level 3 inputs at March 31, 2014 and December 31, 2013. However, in 2013, fixed income securities with a fair value of $32.0 million were transferred out of Level 3 during the year due to the availability of Level 2 pricing at December 31, 2013 that was not available previously.
Equity securities with fair values of $2.9 million were measured using Level 3 inputs at March 31, 2014 and December 31, 2013. An equity security with a fair value of $4.6 million was transferred out of Level 3 during 2013 due to the availability of Level 2 pricing at the date of transfer. In addition, the receivable related to the sale of Selective HR was settled during 2013 and as a result was also transferred out of Level 3.
The following tables provide quantitative information regarding our financial assets and liabilities that were disclosed at fair value at March 31, 2014 and December 31, 2013:
March 31, 2014					Fair Value Measurements Using
($ in thousands)		Assets/			Quoted Prices in			Significant Other			Significant
		Liabilities			Active Markets for			Observable			Unobservable
		Disclosed at			Identical Assets/			Inputs			Inputs
		Fair Value at 3/31/2014			Liabilities			(Level 2)			(Level 3)
					(Level 1)
Financial Assets
HTM:
Foreign government		$	5,552		—			5,552			—
Obligations of states and political subdivisions		364,307			—			364,307			—
Corporate securities		24,464			—			24,464			—
ABS		3,366			—			3,366			—
CMBS		5,847			—			5,847			—
Total HTM fixed income securities		$	403,536		—			403,536			—
Financial Liabilities
Notes payable:
2.90% borrowings from FHLBI		$	13,243		—			13,243			—
1.25% borrowings from FHLBI		45,226			—			45,226			—
7.25% Senior Notes		53,065			—			53,065			—
6.70% Senior Notes		102,810			—			102,810			—
5.875% Senior Notes		165,316			165,316			—			—
Total notes payable		$	379,660		165,316			214,344			—
December 31, 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 12/31/2013			Liabilities			(Level 2)			(Level 3)
					(Level 1)
Financial Assets
HTM:
Foreign government		$	5,591		—			5,591			—
Obligations of states and political subdivisions		369,756			—			369,756			—
Corporate securities		30,274			—			30,274			—
ABS		3,415			—			3,415			—
CMBS		7,945			—			7,945			—
Total HTM fixed income securities		$	416,981		—			416,981			—
Financial Liabilities
Notes payable:
2.90% borrowings from FHLBI		$	13,319		—			13,319			—
1.25% borrowings from FHLBI		45,259			—			45,259			—
7.25% Senior Notes		50,887			—			50,887			—
6.70% Senior Notes		98,247			—			98,247			—
5.875% Senior Notes		146,298			146,298			—			—
Total notes payable		$	354,010		146,298			207,712			—

Reinsurance

Reinsurance	3 Months Ended
	Mar. 31, 2014
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 2013 Annual Report.
		Quarter ended March 31,
	($ in thousands)	2014			2013
	Premiums written:
	Direct	$	557,891		528,816
	Assumed	7,850			8,482
	Ceded	(88,991		)	(87,174	)
	Net	$	476,750		450,124
	Premiums earned:
	Direct	$	536,700		494,066
	Assumed	10,185			12,463
	Ceded	(90,390		)	(85,589	)
	Net	$	456,495		420,940
	Loss and loss expense incurred:
	Direct	$	358,349		365,646
	Assumed	7,479			9,074
	Ceded	(45,282		)	(104,871	)
	Net	$	320,546		269,849
	The growth in direct premium written ("DPW") for our ten insurance subsidiaries ("Insurance Subsidiaries") in First Quarter 2014 compared to First Quarter 2013 reflects pure price increases and retention that we have achieved in our Standard Insurance Operations.
	Direct premiums earned increases in First Quarter 2014 were consistent with the fluctuation in DPW for the twelve-month period ended March 31, 2014 as compared to the twelve-month period ended March 31, 2013.
	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 March 31,
	($ in thousands)	2014			2013
	Ceded premiums written	$	(57,303	)	(56,707	)
	Ceded premiums earned	(58,286		)	(55,327	)
	Ceded loss and loss expense incurred	(7,379		)	(76,176	)

Segment_Information

Segment Information	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Segment Information	'
	Segment Information
	The disaggregated 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 after-tax net investment income and net realized gains and losses.
	In computing the results of each segment, we do not make adjustments for interest expense or net general corporate expenses. While we do not fully allocate taxes to all segments, we do allocate taxes to our investments segment as we manage that segment on after-tax results. We do not maintain separate investment portfolios for the segments and therefore, do not allocate assets to the segments.
	In First Quarter 2014, we sold the renewal rights to our $38 million self-insured group, or "SIG," book of business within the Standard Insurance Operations segment. We decided to opportunistically sell this very small and specialized book of pooled business as a significant portion of the business was produced outside of our standard lines footprint, and proved difficult to grow. As this was a renewal rights sale, we will continue to service policies that were in force at the date of the sale. We continue to remain active in the municipal and public school marketplace for individual risks that procure traditional insurance programs rather than pooling arrangements. The proceeds from this sale, which amounted to $8 million, are included in "Miscellaneous income" within the table below as a component of the Standard Insurance Operations revenue.
	The following summaries present revenues from continuing operations (net investment income and net realized gains on investments in the case of the Investments segment) and pre-tax income from continuing operations for the individual segments:
	Revenue by Segment		Quarter ended March 31,
	($ in thousands)		2014			2013
	Standard Insurance Operations:
	Net premiums earned:
	Commercial automobile		$	82,216		74,347
	Workers compensation		69,413			66,084
	General liability		108,818			97,703
	Commercial property		60,186			53,415
	Businessowners’ policies		20,869			18,540
	Bonds		4,756			4,764
	Other		3,183			2,992
	Total Standard Commercial Lines		349,441			317,845
	Personal automobile		38,226			38,393
	Homeowners		33,298			31,135
	Other		3,294			3,508
	Total Standard Personal Lines		74,818			73,036
	Total Standard Insurance Operations net premiums earned		424,259			390,881
	Miscellaneous income		9,819			2,720
	Total Standard Insurance Operations revenue		434,078			393,601
	E&S Insurance Operations:
	Net premiums earned		32,236			30,059
	Investments:
	Net investment income		35,534			32,870
	Net realized investment gains		7,218			3,355
	Total investment revenues		42,752			36,225
	Total all segments		509,066			459,885
	Other income		5			64
	Total revenues from continuing operations		$	509,071		459,949
	Income from Continuing Operations before Federal Income Tax		Quarter ended March 31,
	($ in thousands)		2014			2013
	Standard Insurance Operations:
	Commercial Lines underwriting (loss) gain		$	(3,630	)	6,102
	Personal Lines underwriting (loss) gain		(2,360		)	5,973
	Total Standard Insurance Operations underwriting (loss) gain, before federal income tax		(5,990		)	12,075
	GAAP combined ratio		101.4		%	96.9	%
	Statutory combined ratio		101.1		%	96.8	%
	E&S Insurance Operations:
	Underwriting gain		975			86
	GAAP combined ratio		97		%	99.7	%
	Statutory combined ratio		97.9		%	98.2	%
	Investments:
	Net investment income		35,534			32,870
	Net realized investment gains		7,218			3,355
	Total investment income, before federal income tax		42,752			36,225
	Tax on investment income		11,575			9,205
	Total investment income, after federal income tax		31,177			27,020
	Reconciliation of Segment Results to Income from Continuing Operations,		Quarter ended March 31,
	before Federal Income Tax
	($ in thousands)		2014			2013
	Standard Insurance Operations underwriting (loss) gain, before federal income tax		$	(5,990	)	12,075
	E&S Insurance Operations underwriting gain, before federal income tax		975			86
	Investment income, before federal income tax		42,752			36,225
	Total all segments		37,737			48,386
	Interest expense		(5,561		)	(5,831	)
	General corporate and other expenses		(7,092		)	(13,687	)
	Income from continuing operations, before federal income tax		$	25,084		28,868

Retirement_Plans

Retirement Plans	3 Months Ended
	Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]	'
Retirement Plans	'
	Retirement Plans
	The following table shows the net periodic benefit cost related to the Retirement Income Plan for Selective Insurance Company of America (“Retirement Income Plan”) and the life insurance benefits provided to eligible Selective Insurance Company of America retirees (referred to as the "Retirement Life Plan"). For more information concerning these plans, refer to Note 15. “Retirement Plans” in Item 8.“Financial Statements and Supplementary Data.” of our 2013 Annual Report.
		Retirement Income Plan							Retirement Life Plan
		Quarter ended March 31,							Quarter ended March 31,
	($ in thousands)	2014				2013			2014		2013
	Components of Net Periodic Benefit Cost:
	Net Periodic Benefit Cost:
	Service cost	$	1,627			2,449			—		—
	Interest cost	3,254				3,303			73		70
	Expected return on plan assets	(3,919		)		(3,848	)		—		—
	Amortization of unrecognized prior service cost	—				10			—		—
	Amortization of unrecognized net actuarial loss	367				1,822			13		18
	Curtailment expense	—				16			—		—
	Total net periodic cost	$	1,329			3,752			86		88
		Retirement Income Plan					Retirement Life Plan
		Quarter ended March 31,					Quarter ended March 31,
		2014			2013		2014			2013
	Weighted-Average Expense Assumptions:
	Discount rate	5.16	%		4.42		4.85	%		4.42
	Expected return on plan assets	6.92			7.4		—			—
	Rate of compensation increase	4			4		—			—
	We presently anticipate contributing $9.8 million to the Retirement Income Plan in 2014, $2.7 million of which has been funded as of March 31, 2014.

Comprehensive_Income

Comprehensive Income	3 Months Ended
	Mar. 31, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]	'
Comprehensive Income	'
	Comprehensive Income
	The components of comprehensive income, both gross and net of tax, for First Quarter 2014 and 2013 are as follows:
	First Quarter 2014
	($ in thousands)		Gross				Tax		Net
	Net income		$	25,084			7,110		17,974
	Components of OCI:
	Unrealized gains on investment securities:
	Unrealized holding gains during the period		32,964				11,538		21,426
	Amounts reclassified into net income:
	HTM securities		(456		)		(160	)	(296	)
	Realized gains on AFS securities		(7,229		)		(2,530	)	(4,699	)
	Net unrealized gains		25,279				8,848		16,431
	Defined benefit pension and post-retirement plans:
	Amounts reclassified into net income:
	Net actuarial loss		380				133		247
	Prior service cost		—				—		—
	Defined benefit pension and post-retirement plans		380				133		247
	Other comprehensive income		25,659				8,981		16,678
	Comprehensive income		$	50,743			16,091		34,652
	First Quarter 2013
	($ in thousands)		Gross				Tax		Net
	Net income		$	27,333			6,025		21,308
	Components of OCI:
	Unrealized gains on investment securities:
	Unrealized holding gains during the period		3,684				1,290		2,394
	Non-credit OTTI recognized in OCI		30				10		20
	Amounts reclassified into net income:
	HTM securities		(717		)		(251	)	(466	)
	Non-credit OTTI		7				3		4
	Realized gains on AFS securities		(5,976		)		(2,092	)	(3,884	)
	Net unrealized losses		(2,972		)		(1,040	)	(1,932	)
	Defined benefit pension and post-retirement plans:
	Net actuarial losses		44,000				15,400		28,600
	Amounts reclassified into net income:
	Net actuarial loss		1,840				644		1,196
	Prior service cost		10				4		6
	Curtailment expense		16				5		11
	Defined benefit pension and post-retirement plans		45,866				16,053		29,813
	Other comprehensive income		42,894				15,013		27,881
	Comprehensive income		$	70,227			21,038		49,189
	The balances of, and changes in, each component of AOCI (net of taxes) as of March 31, 2014 are as follows:
	March 31, 2014		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, 2013		$	(1,599	)		1,467		51,635		51,503		(26,652	)	24,851
	OCI before reclassifications		—				—		21,426		21,426		—		21,426
	Amounts reclassified from AOCI		—				(296	)	(4,699	)	(4,995	)	247		(4,748	)
	Net current period OCI		—				(296	)	16,727		16,431		247		16,678
	Balance, March 31, 2014		$	(1,599	)		1,171		68,362		67,934		(26,405	)	41,529
	The reclassifications out of AOCI for First Quarter 2014 are as follows:
	($ in thousands)	Quarter ended March 31, 2014				Affected Line Item in the Unaudited Consolidated Statement of Income
	HTM related
	Unrealized losses on HTM disposals	24				Net realized gains
	Amortization of net unrealized gains on HTM securities	(480		)		Net investment income earned
		(456		)		Income from continuing operations, before federal income tax
		160				Total federal income tax expense
		(296		)		Net income
	Realized gains and losses on AFS
	Realized gains on AFS disposals and OTTI	(7,229		)		Net realized gains
		(7,229		)		Income from continuing operations, before federal income tax
		2,530				Total federal income tax expense
		(4,699		)		Net income
	Defined benefit pension and post-retirement life plans
Net actuarial loss	87				Loss and loss expense incurred
	293				Policy acquisition costs
Total defined benefit pension and post-retirement life plans	380				Income from continuing operations, before federal income tax
	(133		)		Total federal income tax expense
	247				Net income
Total reclassifications for the period	$	(4,748	)		Net income

Litigation

Litigation	3 Months Ended
	Mar. 31, 2014
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: (i) liability insurers defending or providing indemnity for third-party claims brought against insureds; or (ii) insurers defending first-party coverage claims brought against them. We account for such activity through the establishment of unpaid loss and loss expense reserves. We expect that 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.

Statements_of_Cash_Flow_Tables

Statements of Cash Flow (Tables)	3 Months Ended
	Mar. 31, 2014
Supplemental Cash Flow Information [Abstract]	'
Schedule of Cash Flow, Supplemental Disclosures	'
		Three Months ended March 31,
	($ in thousands)	2014		2013
	Cash paid during the period for:
	Interest	$	2,973	1,964
	Federal income tax	2,000		—
	Non-cash items:
	Tax-free exchange of fixed income securities, AFS	—		8,470
	Tax-free exchange of fixed income securities, HTM	15		7,168

Investments_Tables

Investments (Tables)	3 Months Ended
	Mar. 31, 2014
Investments [Line Items]	'
Schedule of Held-to-maturity Securities	'
	March 31, 2014
	($ in thousands)	Amortized			Net		Carrying			Unrecognized		Unrecognized Holding		Fair
		Cost			Unrealized Gains		Value			Holding		Losses		Value
					(Losses)					Gains
	Foreign government	$	5,292		110		5,402			150		—		5,552
	Obligations of state and political subdivisions	344,360			3,475		347,835			16,472		—		364,307
	Corporate securities	21,903			(341	)	21,562			2,902		—		24,464
	Asset-backed securities (“ABS”)	3,347			(621	)	2,726			640		—		3,366
	Commercial mortgage-backed securities (“CMBS”)	5,353			(822	)	4,531			1,316		—		5,847
	Total HTM fixed income securities	$	380,255		1,801		382,056			21,480		—		403,536
	December 31, 2013
	($ in thousands)	Amortized			Net		Carrying			Unrecognized		Unrecognized Holding		Fair
		Cost			Unrealized Gains		Value			Holding		Losses		Value
					(Losses)					Gains
	Foreign government	$	5,292		131		5,423			168		—		5,591
	Obligations of state and political subdivisions	348,109			4,013		352,122			17,634		—		369,756
	Corporate securities	28,174			(346	)	27,828			2,446		—		30,274
	ABS	3,413			(655	)	2,758			657		—		3,415
	CMBS	5,634			(886	)	4,748			3,197		—		7,945
	Total HTM fixed income securities	$	390,622		2,257		392,879			24,102		—		416,981
Schedule Of Available For Sale Securities	'
	March 31, 2014
	($ in thousands)	Cost/			Unrealized		Unrealized			Fair
		Amortized			Gains		Losses			Value
		Cost
	U.S. government and government agencies	$	161,428		10,007		(370	)		171,065
	Foreign government	31,538			912		(29	)		32,421
	Obligations of states and political subdivisions	963,237			26,617		(10,687	)		979,167
	Corporate securities	1,777,186			48,305		(9,793	)		1,815,698
	ABS	131,386			908		(360	)		131,934
	CMBS1	172,386			4,686		(2,256	)		174,816
	Residential mortgage-backed	511,295			7,210		(7,753	)		510,752
	securities (“RMBS”)2
	AFS fixed income securities	3,748,456			98,645		(31,248	)		3,815,853
	AFS equity securities	162,370			35,434		(117	)		197,687
	Total AFS securities	$	3,910,826		134,079		(31,365	)		4,013,540
	December 31, 2013
	($ in thousands)	Cost/			Unrealized		Unrealized			Fair
		Amortized			Gains		Losses			Value
		Cost
	U.S. government and government agencies	$	163,218		10,661		(504	)		173,375
	Foreign government	29,781			906		(72	)		30,615
	Obligations of states and political subdivisions	946,455			25,194		(20,025	)		951,624
	Corporate securities	1,707,928			44,004		(17,049	)		1,734,883
	ABS	140,430			934		(468	)		140,896
	CMBS1	172,288			2,462		(3,466	)		171,284
	RMBS2	515,877			7,273		(10,291	)		512,859
	AFS fixed income securities	3,675,977			91,434		(51,875	)		3,715,536
	AFS equity securities	155,350			37,517		(96	)		192,771
	Total AFS securities	$	3,831,327		128,951		(51,971	)		3,908,307
	1 CMBS includes government guaranteed agency securities with a fair value of $24.5 million at March 31, 2014 and $30.0 million at December 31, 2013.
	2 RMBS includes government guaranteed agency securities with a fair value of $48.2 million at March 31, 2014 and $55.2 million at December 31, 2013.
Schedule of Fair Value and Gross Pre-Tax Net Unrealized/Unrecognized Loss of Securities by Length of Time	'
	March 31, 2014	Less than 12 months					12 months or longer
	($ in thousands)	Fair Value			Unrealized		Fair Value			Unrealized
					Losses1					Losses1
	AFS securities
	U.S. government and government agencies	$	13,119		(370	)	—			—
	Foreign government	1,753			(9	)	2,978			(20	)
	Obligations of states and political subdivisions	373,064			(9,984	)	20,096			(703	)
	Corporate securities	464,163			(8,636	)	17,713			(1,157	)
	ABS	23,855			(360	)	—			—
	CMBS	72,437			(1,962	)	7,466			(294	)
	RMBS	221,314			(7,294	)	4,823			(459	)
	Total fixed income securities	1,169,705			(28,615	)	53,076			(2,633	)
	Equity securities	1,938			(117	)	—			—
	Subtotal	$	1,171,643		(28,732	)	53,076			(2,633	)
		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	$	—		—		—			445		(19	)	18
	ABS	—			—		—			2,495		(621	)	592
	Subtotal	$	—		—		—			2,940		(640	)	610
	Total AFS and HTM	$	1,171,643		(28,732	)	—			56,016		(3,273	)	610
	December 31, 2013	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	$	16,955		(500	)	507			(4	)
	Foreign government	2,029			(30	)	2,955			(42	)
	Obligations of states and political subdivisions	442,531			(19,120	)	13,530			(905	)
	Corporate securities	511,100			(15,911	)	14,771			(1,138	)
	ABS	68,725			(468	)	—			—
	CMBS	100,396			(2,950	)	6,298			(516	)
	RMBS	268,943			(10,031	)	2,670			(260	)
	Total fixed income securities	1,410,679			(49,010	)	40,731			(2,865	)
	Equity securities	1,124			(96	)	—			—
	Subtotal	$	1,411,803		(49,106	)	40,731			(2,865	)
		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	$	65		(5	)	5			441		(20	)	14
	ABS	—			—		—			2,490		(655	)	621
	Subtotal	65			(5	)	5			2,931		(675	)	635
	Total AFS and HTM	$	1,411,868		(49,111	)	5			43,662		(3,540	)	635
	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)
	March 31, 2014					December 31, 2013
	Number of	% of Market/Book	Unrealized/			Number of	% of	Unrealized/
	Issues		Unrecognized Loss			Issues	Market/Book	Unrecognized
								Loss
	466	80% - 99%	$	31,395		556	80% - 99%	$	51,835
	—	60% - 79%	—			1	60% - 79%	176
	—	40% - 59%	—			—	40% - 59%	—
	—	20% - 39%	—			—	20% - 39%	—
	—	0% - 19%	—			—	0% - 19%	—
			$	31,395				$	52,011
Schedule Of Other Investment Portfolio By Strategy And Remaining Commitment Amount Associated With Each Strategy	'
	Other Investments	Carrying Value					March 31,
							2014
	($ in thousands)	March 31,			December 31,		Remaining Commitment
		2014			2013
	Alternative Investments
	Secondary private equity	$	23,595		25,618		6,479
	Private equity	21,117			20,192		9,959
	Energy/power generation	17,978			17,361		6,984
	Mezzanine financing	13,831			12,738		15,038
	Distressed debt	10,882			11,579		2,971
	Real estate	10,728			11,698		10,178
	Venture capital	7,019			7,025		350
	Total alternative investments	105,150			106,211		51,959
	Other securities	1,570			1,664		597
	Total other investments	$	106,720		107,875		52,556
Schedule Of Aggregated Summarized Income Statement Financial Information For Partnerhips In Our Alternative Investment Portfolio	'
	Income Statement Information	Quarter ended December 31,
	($ in millions)	2013			2012
	Net investment income	$	65.1		204.8
	Realized gains	63.3			593.4
	Net change in unrealized appreciation (depreciation)	505.9			(417.5	)
	Net income	$	634.3		380.7
	Selective’s insurance subsidiaries’ other investments income	$	5.2		3.6
Schedule of Net Investment Income earned	'
		Quarter ended March 31,
	($ in thousands)	2014			2013
	Fixed income securities	$	31,028		30,089
	Equity securities	1,449			1,207
	Short-term investments	19			52
	Other investments	5,218			3,602
	Investment expenses	(2,180		)	(2,080	)
	Net investment income earned	$	35,534		32,870
Schedule of OTTI By Asset Type	'
	First Quarter 2014	Gross			Included in Other		Recognized in
					Comprehensive		Earnings
	($ in thousands)				Income (“OCI”)
	AFS securities
	Equity securities	$	963		—		963
	Total AFS Securities	963			—		963
	OTTI losses	$	963		—		963
	First Quarter 2013	Gross			Included in OCI		Recognized in Earnings
	($ in thousands)
	AFS fixed income securities
	RMBS	$	(22	)	(30	)	8
	Total AFS fixed income securities	(22		)	(30	)	8
	Equity securities	217			—		217
	Total AFS securities	195			(30	)	225
	Other investments	1,724			—		1,724
	OTTI losses	$	1,919		(30	)	1,949
Schedule of Gross Credit Loss Impairments on Fixed Maturity Securities for Which a Portion of the OTTI Charge was Recognized in OCI	'
		Quarter ended March 31,
	($ in thousands)	2014			2013
	Balance, beginning of period	$	7,488		7,477
	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	—			9
	Accretion of credit loss impairments previously recognized due to an increase in cash flows expected to be collected	—			—
	Balance, end of period	$	7,488		7,486
Schedule of Components of Net Realized Gains Excluding OTTI Charges	'
		Quarter ended March 31,
	($ in thousands)	2014			2013
	HTM fixed income securities
	Gains	$	—		—
	Losses	(11		)	(37	)
	AFS fixed income securities
	Gains	158			951
	Losses	(112		)	(253	)
	AFS equity securities
	Gains	8,317			5,671
	Losses	(171		)	(168	)
	Other investments
	Gains	—			—
	Losses	—			(860	)
	Total other net realized investment gains	8,181			5,304
	Total OTTI charges recognized in earnings	(963		)	(1,949	)
	Total net realized gains	$	7,218		3,355
Held To Maturity Fixed Income 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	$	80,337		81,332
	Due after one year through five years	270,608			287,045
	Due after five years through 10 years	31,111			35,159
	Total HTM fixed income securities	$	382,056		403,536
AFS Fixed Income Securities [Member]	'
Investments [Line Items]	'
Schedule Of Fixed Maturity Securities By Contractual Maturities	'
	($ in thousands)	Fair Value
	Due in one year or less	$	425,744
	Due after one year through five years	1,991,515
	Due after five years through 10 years	1,345,666
	Due after 10 years	52,928
	Total AFS fixed income securities	$	3,815,853

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Schedule of The Carrying Amounts and Estimated Fair Values of Financial Instruments	'
			March 31, 2014						December 31, 2013
	($ in thousands)		Carrying Amount			Fair			Carrying Amount			Fair
						Value						Value
	Financial Assets
	Fixed income securities:
	HTM		$	382,056		403,536			392,879			416,981
	AFS		3,815,853			3,815,853			3,715,536			3,715,536
	Equity securities, AFS		197,687			197,687			192,771			192,771
	Short-term investments		137,733			137,733			174,251			174,251
	Financial Liabilities
	Notes payable:
	2.90% borrowings from FHLBI		13,000			13,243			13,000			13,319
	1.25% borrowings from FHLBI		45,000			45,226			45,000			45,259
	7.25% Senior Notes		49,917			53,065			49,916			50,887
	6.70% Senior Notes		99,503			102,810			99,498			98,247
	5.875% Senior Notes		185,000			165,316			185,000			146,298
	Total notes payable		$	392,420		379,660			392,414			354,010
Schedule of Quantitative Disclosures of Our Financial Assets That Were Measured At Fair Value	'
	March 31, 2014					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 3/31/2014			Liabilities (Level 1)1			(Level 2)1
	Description
	Measured on a recurring basis:
	AFS:
	U.S. government and government agencies		$	171,065		51,796			119,269			—
	Foreign government		32,421			—			32,421			—
	Obligations of states and political subdivisions		979,167			—			979,167			—
	Corporate securities		1,815,698			—			1,815,698			—
	ABS		131,934			—			131,934			—
	CMBS		174,816			—			174,816			—
	RMBS		510,752			—			510,752			—
	Total AFS fixed income securities		3,815,853			51,796			3,764,057			—
	Equity securities		197,687			194,787			—			2,900
	Total AFS Securities		4,013,540			246,583			3,764,057			2,900
	Short-term investments		137,733			137,733			—			—
	Total assets measured at fair value		$	4,151,273		384,316			3,764,057			2,900
	1	There were no transfers of securities between Level 1 and Level 2.
	December 31, 2013					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 12/31/13			(Level 1)1			(Level 2)1
	Description
	Measured on a recurring basis:
	AFS:
	U.S. government and government agencies		$	173,375		52,153			121,222			—
	Foreign government		30,615			—			30,615			—
	Obligations of states and political subdivisions		951,624			—			951,624			—
	Corporate securities		1,734,883			—			1,734,883			—
	ABS		140,896			—			140,896			—
	CMBS		171,284			—			171,284			—
	RMBS		512,859			—			512,859			—
	Total AFS fixed income securities		3,715,536			52,153			3,663,383			—
	Equity securities		192,771			189,871			—			2,900
	Total AFS Securities		3,908,307			242,024			3,663,383			2,900
	Short-term investments		174,251			174,251			—			—
	Total assets measured at fair value		$	4,082,558		416,275			3,663,383			2,900
	1	There were no transfers of securities between Level 1 and Level 2.
Schedule of Summary of the Changes in Fair Value of Securities measured Using Level 3 Inputs	'
	31-Dec-13
	($ in thousands)		Government			Corporate				ABS			CMBS			Equity			Receivable for			Total
																			Proceeds
																			Related to Sale
																			of Selective HR Solutions ("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		)		(74		)	772			3,935			—			4,089
	Net income2,3		(76		)	—				—			361			—			(1,480		)	(1,195		)
	Purchases		—			—				—			—			—			—			—
	Sales		—			—				—			—			—			—			—
	Issuances		—			—				—			—			—			—			—
	Settlements		(1,847		)	(168		)		—			(2,420		)	—			(225		)	(4,660		)
	Transfers into Level 3		—			—				—			—			—			—			—
	Transfers out of Level 3		(17,329		)	(2,771		)		(5,994		)	(5,875		)	(4,642		)	(1,000		)	(37,611		)
	Fair value, December 31, 2013		$	—		$	—			$	—		$	—		$	2,900		$	—		$	2,900
	1 Amounts are reported in “Unrealized holding (losses) gains arising during period” on the Consolidated Statements of Comprehensive Income in our 2013 Annual Report.
	2 Amounts are reported in “Net realized gains” for realized gains and losses and “Net investment income earned” for amortization of securities on the Consolidated Statements of Income in our 2013 Annual Report.
	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 Consolidated Statements of Income in our 2013 Annual Report.
Schedule of Quantitative Information of Our Financial Assets and Liabilities That Were Disclosed at Fair Value	'
	:
	March 31, 2014					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 3/31/2014			Liabilities			(Level 2)			(Level 3)
						(Level 1)
	Financial Assets
	HTM:
	Foreign government		$	5,552		—			5,552			—
	Obligations of states and political subdivisions		364,307			—			364,307			—
	Corporate securities		24,464			—			24,464			—
	ABS		3,366			—			3,366			—
	CMBS		5,847			—			5,847			—
	Total HTM fixed income securities		$	403,536		—			403,536			—
	Financial Liabilities
	Notes payable:
	2.90% borrowings from FHLBI		$	13,243		—			13,243			—
	1.25% borrowings from FHLBI		45,226			—			45,226			—
	7.25% Senior Notes		53,065			—			53,065			—
	6.70% Senior Notes		102,810			—			102,810			—
	5.875% Senior Notes		165,316			165,316			—			—
	Total notes payable		$	379,660		165,316			214,344			—
	December 31, 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 12/31/2013			Liabilities			(Level 2)			(Level 3)
						(Level 1)
	Financial Assets
	HTM:
	Foreign government		$	5,591		—			5,591			—
	Obligations of states and political subdivisions		369,756			—			369,756			—
	Corporate securities		30,274			—			30,274			—
	ABS		3,415			—			3,415			—
	CMBS		7,945			—			7,945			—
	Total HTM fixed income securities		$	416,981		—			416,981			—
	Financial Liabilities
	Notes payable:
	2.90% borrowings from FHLBI		$	13,319		—			13,319			—
	1.25% borrowings from FHLBI		45,259			—			45,259			—
	7.25% Senior Notes		50,887			—			50,887			—
	6.70% Senior Notes		98,247			—			98,247			—
	5.875% Senior Notes		146,298			146,298			—			—
	Total notes payable		$	354,010		146,298			207,712			—

Reinsurance_Tables

Reinsurance (Tables)	3 Months Ended
	Mar. 31, 2014
Reinsurance Disclosures [Abstract]	'
Schedule of List Of Direct, Assumed, And Ceded Reinsurance Amounts	'
		Quarter ended March 31,
	($ in thousands)	2014			2013
	Premiums written:
	Direct	$	557,891		528,816
	Assumed	7,850			8,482
	Ceded	(88,991		)	(87,174	)
	Net	$	476,750		450,124
	Premiums earned:
	Direct	$	536,700		494,066
	Assumed	10,185			12,463
	Ceded	(90,390		)	(85,589	)
	Net	$	456,495		420,940
	Loss and loss expense incurred:
	Direct	$	358,349		365,646
	Assumed	7,479			9,074
	Ceded	(45,282		)	(104,871	)
	Net	$	320,546		269,849
Schedule of Ceded Premiums and Losses Related to Flood Operations	'
	NFIP	Quarter ended March 31,
	($ in thousands)	2014			2013
	Ceded premiums written	$	(57,303	)	(56,707	)
	Ceded premiums earned	(58,286		)	(55,327	)
	Ceded loss and loss expense incurred	(7,379		)	(76,176	)

Segment_Information_Tables

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Schedule of Revenue from Continuing Operations By Segment	'
	Revenue by Segment	Quarter ended March 31,
	($ in thousands)	2014			2013
	Standard Insurance Operations:
	Net premiums earned:
	Commercial automobile	$	82,216		74,347
	Workers compensation	69,413			66,084
	General liability	108,818			97,703
	Commercial property	60,186			53,415
	Businessowners’ policies	20,869			18,540
	Bonds	4,756			4,764
	Other	3,183			2,992
	Total Standard Commercial Lines	349,441			317,845
	Personal automobile	38,226			38,393
	Homeowners	33,298			31,135
	Other	3,294			3,508
	Total Standard Personal Lines	74,818			73,036
	Total Standard Insurance Operations net premiums earned	424,259			390,881
	Miscellaneous income	9,819			2,720
	Total Standard Insurance Operations revenue	434,078			393,601
	E&S Insurance Operations:
	Net premiums earned	32,236			30,059
	Investments:
	Net investment income	35,534			32,870
	Net realized investment gains	7,218			3,355
	Total investment revenues	42,752			36,225
	Total all segments	509,066			459,885
	Other income	5			64
	Total revenues from continuing operations	$	509,071		459,949
Schedule of Segment Income	'
	Income from Continuing Operations before Federal Income Tax	Quarter ended March 31,
	($ in thousands)	2014			2013
	Standard Insurance Operations:
	Commercial Lines underwriting (loss) gain	$	(3,630	)	6,102
	Personal Lines underwriting (loss) gain	(2,360		)	5,973
	Total Standard Insurance Operations underwriting (loss) gain, before federal income tax	(5,990		)	12,075
	GAAP combined ratio	101.4		%	96.9	%
	Statutory combined ratio	101.1		%	96.8	%
	E&S Insurance Operations:
	Underwriting gain	975			86
	GAAP combined ratio	97		%	99.7	%
	Statutory combined ratio	97.9		%	98.2	%
	Investments:
	Net investment income	35,534			32,870
	Net realized investment gains	7,218			3,355
	Total investment income, before federal income tax	42,752			36,225
	Tax on investment income	11,575			9,205
	Total investment income, after federal income tax	31,177			27,020
Schedule of Reconciliation of Segment Results to Income From Continuing Operations, Before Federal Income Tax	'
	Reconciliation of Segment Results to Income from Continuing Operations,	Quarter ended March 31,
	before Federal Income Tax
	($ in thousands)	2014			2013
	Standard Insurance Operations underwriting (loss) gain, before federal income tax	$	(5,990	)	12,075
	E&S Insurance Operations underwriting gain, before federal income tax	975			86
	Investment income, before federal income tax	42,752			36,225
	Total all segments	37,737			48,386
	Interest expense	(5,561		)	(5,831	)
	General corporate and other expenses	(7,092		)	(13,687	)
	Income from continuing operations, before federal income tax	$	25,084		28,868

Retirement_Plans_Table

Retirement Plans (Table)	3 Months Ended
	Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]	'
Schedule of Components Of Net Periodic Benefit Cost And Other Amounts Recognized In Other Comprehensive Income	'
		Retirement Income Plan							Retirement Life Plan
		Quarter ended March 31,							Quarter ended March 31,
	($ in thousands)	2014				2013			2014		2013
	Components of Net Periodic Benefit Cost:
	Net Periodic Benefit Cost:
	Service cost	$	1,627			2,449			—		—
	Interest cost	3,254				3,303			73		70
	Expected return on plan assets	(3,919		)		(3,848	)		—		—
	Amortization of unrecognized prior service cost	—				10			—		—
	Amortization of unrecognized net actuarial loss	367				1,822			13		18
	Curtailment expense	—				16			—		—
	Total net periodic cost	$	1,329			3,752			86		88
Schedule Of Weighted-Average Expense Assumptions	'
		Retirement Income Plan					Retirement Life Plan
		Quarter ended March 31,					Quarter ended March 31,
		2014			2013		2014			2013
	Weighted-Average Expense Assumptions:
	Discount rate	5.16	%		4.42		4.85	%		4.42
	Expected return on plan assets	6.92			7.4		—			—
	Rate of compensation increase	4			4		—			—

Comprehensive_Income_Tables

Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]	'
Schedule of Components of Comprehensive Income-Gross and Net of Tax	'
	First Quarter 2014
	($ in thousands)		Gross				Tax		Net
	Net income		$	25,084			7,110		17,974
	Components of OCI:
	Unrealized gains on investment securities:
	Unrealized holding gains during the period		32,964				11,538		21,426
	Amounts reclassified into net income:
	HTM securities		(456		)		(160	)	(296	)
	Realized gains on AFS securities		(7,229		)		(2,530	)	(4,699	)
	Net unrealized gains		25,279				8,848		16,431
	Defined benefit pension and post-retirement plans:
	Amounts reclassified into net income:
	Net actuarial loss		380				133		247
	Prior service cost		—				—		—
	Defined benefit pension and post-retirement plans		380				133		247
	Other comprehensive income		25,659				8,981		16,678
	Comprehensive income		$	50,743			16,091		34,652
	First Quarter 2013
	($ in thousands)		Gross				Tax		Net
	Net income		$	27,333			6,025		21,308
	Components of OCI:
	Unrealized gains on investment securities:
	Unrealized holding gains during the period		3,684				1,290		2,394
	Non-credit OTTI recognized in OCI		30				10		20
	Amounts reclassified into net income:
	HTM securities		(717		)		(251	)	(466	)
	Non-credit OTTI		7				3		4
	Realized gains on AFS securities		(5,976		)		(2,092	)	(3,884	)
	Net unrealized losses		(2,972		)		(1,040	)	(1,932	)
	Defined benefit pension and post-retirement plans:
	Net actuarial losses		44,000				15,400		28,600
	Amounts reclassified into net income:
	Net actuarial loss		1,840				644		1,196
	Prior service cost		10				4		6
	Curtailment expense		16				5		11
	Defined benefit pension and post-retirement plans		45,866				16,053		29,813
	Other comprehensive income		42,894				15,013		27,881
	Comprehensive income		$	70,227			21,038		49,189
Schedule of Components of Accumulated Other Comprehensive Income	'
	March 31, 2014		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, 2013		$	(1,599	)		1,467		51,635		51,503		(26,652	)	24,851
	OCI before reclassifications		—				—		21,426		21,426		—		21,426
	Amounts reclassified from AOCI		—				(296	)	(4,699	)	(4,995	)	247		(4,748	)
	Net current period OCI		—				(296	)	16,727		16,431		247		16,678
	Balance, March 31, 2014		$	(1,599	)		1,171		68,362		67,934		(26,405	)	41,529
Schedule of Reclassifications Out Of Accumulated Other Comprehensive Income	'
	($ in thousands)	Quarter ended March 31, 2014				Affected Line Item in the Unaudited Consolidated Statement of Income
	HTM related
	Unrealized losses on HTM disposals	24				Net realized gains
	Amortization of net unrealized gains on HTM securities	(480		)		Net investment income earned
		(456		)		Income from continuing operations, before federal income tax
		160				Total federal income tax expense
		(296		)		Net income
	Realized gains and losses on AFS
	Realized gains on AFS disposals and OTTI	(7,229		)		Net realized gains
		(7,229		)		Income from continuing operations, before federal income tax
		2,530				Total federal income tax expense
		(4,699		)		Net income
	Defined benefit pension and post-retirement life plans
	Net actuarial loss	87				Loss and loss expense incurred
		293				Policy acquisition costs
	Total defined benefit pension and post-retirement life plans	380				Income from continuing operations, before federal income tax
		(133		)		Total federal income tax expense
		247				Net income
	Total reclassifications for the period	$	(4,748	)		Net income

Organization_Narrative_Details

Organization (Narrative) (Details)	3 Months Ended
	Mar. 31, 2014
Number of Operating Segments	3

Statements_of_Cash_Flow_Cash_F

Statements of Cash Flow (Cash Flow Supplemental Disclosures) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Interest	$2,973,000	$1,964,000
Federal income tax	2,000,000	0
Tax-free exchange of fixed maturity security, AFS	0	8,470,000
Tax-free exchange of fixed maturity security, HTM	15,000	7,168,000
National Flood Insurance Program [Member]	'	'
Restricted Cash	$6,100,000	'

Investments_HeldToMaturity_Sec

Investments (Held-To-Maturity Securities Disclosure) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	$380,255	$390,622
Net Unrealized Gains (Losses)	1,801	2,257
Carrying Value	382,056	392,879
Unrecognized Holding Gains	21,480	24,102
Unrecoginzed Holding Losses	0	0
Fixed income securities, held-to-maturity, fair value	403,536	416,981
Held To Maturity securities average duration	'2 years 2 months	'
Foreign Government [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	5,292	5,292
Net Unrealized Gains (Losses)	110	131
Carrying Value	5,402	5,423
Unrecognized Holding Gains	150	168
Unrecoginzed Holding Losses	0	0
Fixed income securities, held-to-maturity, fair value	5,552	5,591
Obligations of States and Political Subdivisions [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	344,360	348,109
Net Unrealized Gains (Losses)	3,475	4,013
Carrying Value	347,835	352,122
Unrecognized Holding Gains	16,472	17,634
Unrecoginzed Holding Losses	0	0
Fixed income securities, held-to-maturity, fair value	364,307	369,756
Corporate Securities [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	21,903	28,174
Net Unrealized Gains (Losses)	-341	-346
Carrying Value	21,562	27,828
Unrecognized Holding Gains	2,902	2,446
Unrecoginzed Holding Losses	0	0
Fixed income securities, held-to-maturity, fair value	24,464	30,274
Asset-backed Securities [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	3,347	3,413
Net Unrealized Gains (Losses)	-621	-655
Carrying Value	2,726	2,758
Unrecognized Holding Gains	640	657
Unrecoginzed Holding Losses	0	0
Fixed income securities, held-to-maturity, fair value	3,366	3,415
Commercial Mortgage-backed Securities (CMBS) [Member]	'	'
Schedule of Held-to-maturity Securities [Line Items]	'	'
Amortized Cost	5,353	5,634
Net Unrealized Gains (Losses)	-822	-886
Carrying Value	4,531	4,748
Unrecognized Holding Gains	1,316	3,197
Unrecoginzed Holding Losses	0	0
Fixed income securities, held-to-maturity, fair value	$5,847	$7,945

Investments_AvailableForSale_S

Investments (Available-For-Sale Securities Disclosure) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	$3,910,826,000		$3,831,327,000
Unrealized Gains	134,079,000		128,951,000
Unrealized Losses	-31,365,000		-51,971,000
Fair Value	4,013,540,000		3,908,307,000
AFS Fixed Income Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	3,748,456,000		3,675,977,000
Unrealized Gains	98,645,000		91,434,000
Unrealized Losses	-31,248,000		-51,875,000
Fair Value	3,815,853,000		3,715,536,000
AFS Fixed Income Securities [Member] | U.S. Government and Government Agencies [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	161,428,000		163,218,000
Unrealized Gains	10,007,000		10,661,000
Unrealized Losses	-370,000		-504,000
Fair Value	171,065,000		173,375,000
AFS Fixed Income Securities [Member] | Foreign Government [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	31,538,000		29,781,000
Unrealized Gains	912,000		906,000
Unrealized Losses	-29,000		-72,000
Fair Value	32,421,000		30,615,000
AFS Fixed Income Securities [Member] | Obligations of States and Political Subdivisions [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	963,237,000		946,455,000
Unrealized Gains	26,617,000		25,194,000
Unrealized Losses	-10,687,000		-20,025,000
Fair Value	979,167,000		951,624,000
AFS Fixed Income Securities [Member] | Corporate Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	1,777,186,000		1,707,928,000
Unrealized Gains	48,305,000		44,004,000
Unrealized Losses	-9,793,000		-17,049,000
Fair Value	1,815,698,000		1,734,883,000
AFS Fixed Income Securities [Member] | Asset-backed Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	131,386,000		140,430,000
Unrealized Gains	908,000		934,000
Unrealized Losses	-360,000		-468,000
Fair Value	131,934,000		140,896,000
AFS Fixed Income Securities [Member] | Commercial Mortgage-backed Securities (CMBS) [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	172,386,000	[1]	172,288,000	[1]
Unrealized Gains	4,686,000	[1]	2,462,000	[1]
Unrealized Losses	-2,256,000	[1]	-3,466,000	[1]
Fair Value	174,816,000	[1]	171,284,000	[1]
Government guaranteed agency securities fair value	24,500,000		30,000,000
AFS Fixed Income Securities [Member] | Residential Mortgage Backed Securities (RMBS) [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	511,295,000	[2]	515,877,000	[2]
Unrealized Gains	7,210,000	[2]	7,273,000	[2]
Unrealized Losses	-7,753,000	[2]	-10,291,000	[2]
Fair Value	510,752,000	[2]	512,859,000	[2]
Government guaranteed agency securities fair value	48,200,000		55,200,000
Equity Securities [Member]	'		'
Schedule of Available-for-sale Securities [Line Items]	'		'
Cost/Amortized Cost	162,370,000		155,350,000
Unrealized Gains	35,434,000		37,517,000
Unrealized Losses	-117,000		-96,000
Fair Value	$197,687,000		$192,771,000
[1]	CMBS includes government guaranteed agency securities with a fair value of $24.5 million at March 31, 2014 and $30.0 million at December 31, 2013.
[2]	RMBS includes government guaranteed agency securities with a fair value of $48.2 million at March 31, 2014 and $55.2 million at December 31, 2013.

Investments_Fair_Value_and_Gro

Investments (Fair Value and Gross Pre-Tax Net Unrealized Unrecognized Loss of Securities By Length of Time) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
AFS Fair Value, Less than 12 months	$1,171,643		$1,411,803
AFS Unrealized Losses, Less than 12 month	-28,732	[1]	-49,106	[1]
AFS Fair Value, 12 months or longer	53,076		40,731
AFS Unrealized Losses, 12 months or longer	-2,633	[1]	-2,865	[1]
HTM Fair Value, Less than 12 months	0		65
HTM Unrealized Losses, Less than 12 months	0	[1]	-5	[1]
HTM Unrecognized Gains, Less than 12 months	0	[2]	5	[2]
HTM Fair Value, 12 months or longer	2,940		2,931
HTM Unrealized Losses, 12 months or longer	-640	[1]	-675	[1]
HTM Unrecognized Gains, 12 months or longer	610	[2]	635	[2]
Total AFS and HTM Fair Value, Less than 12 months	1,171,643		1,411,868
Total AFS and HTM Unrealized Losses, Less than 12 months	-28,732	[1]	-49,111	[1]
Total AFS and HTM Fair Value, 12 months or longer	56,016		43,662
Total AFS and HTM Unrealized Losses, 12 months or longer	-3,273	[1]	-3,540	[1]
Obligations of States and Political Subdivisions [Member]	'		'
HTM Fair Value, Less than 12 months	0		65
HTM Unrealized Losses, Less than 12 months	0	[1]	-5	[1]
HTM Unrecognized Gains, Less than 12 months	0	[2]	5	[2]
HTM Fair Value, 12 months or longer	445		441
HTM Unrealized Losses, 12 months or longer	-19	[1]	-20	[1]
HTM Unrecognized Gains, 12 months or longer	18	[2]	14	[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	2,495		2,490
HTM Unrealized Losses, 12 months or longer	-621	[1]	-655	[1]
HTM Unrecognized Gains, 12 months or longer	592	[2]	621	[2]
AFS Fixed Income Securities [Member]	'		'
AFS Fair Value, Less than 12 months	1,169,705		1,410,679
AFS Unrealized Losses, Less than 12 month	-28,615	[1]	-49,010	[1]
AFS Fair Value, 12 months or longer	53,076		40,731
AFS Unrealized Losses, 12 months or longer	-2,633	[1]	-2,865	[1]
AFS Fixed Income Securities [Member] | U.S. Government and Government Agencies [Member]	'		'
AFS Fair Value, Less than 12 months	13,119		16,955
AFS Unrealized Losses, Less than 12 month	-370	[1]	-500	[1]
AFS Fair Value, 12 months or longer	0		507
AFS Unrealized Losses, 12 months or longer	0	[1]	-4	[1]
AFS Fixed Income Securities [Member] | Foreign Government [Member]	'		'
AFS Fair Value, Less than 12 months	1,753		2,029
AFS Unrealized Losses, Less than 12 month	-9	[1]	-30	[1]
AFS Fair Value, 12 months or longer	2,978		2,955
AFS Unrealized Losses, 12 months or longer	-20	[1]	-42	[1]
AFS Fixed Income Securities [Member] | Obligations of States and Political Subdivisions [Member]	'		'
AFS Fair Value, Less than 12 months	373,064		442,531
AFS Unrealized Losses, Less than 12 month	-9,984	[1]	-19,120	[1]
AFS Fair Value, 12 months or longer	20,096		13,530
AFS Unrealized Losses, 12 months or longer	-703	[1]	-905	[1]
AFS Fixed Income Securities [Member] | Corporate Securities [Member]	'		'
AFS Fair Value, Less than 12 months	464,163		511,100
AFS Unrealized Losses, Less than 12 month	-8,636	[1]	-15,911	[1]
AFS Fair Value, 12 months or longer	17,713		14,771
AFS Unrealized Losses, 12 months or longer	-1,157	[1]	-1,138	[1]
AFS Fixed Income Securities [Member] | Asset-backed Securities [Member]	'		'
AFS Fair Value, Less than 12 months	23,855		68,725
AFS Unrealized Losses, Less than 12 month	-360	[1]	-468	[1]
AFS Fair Value, 12 months or longer	0		0
AFS Unrealized Losses, 12 months or longer	0	[1]	0	[1]
AFS Fixed Income Securities [Member] | Commercial Mortgage-backed Securities (CMBS) [Member]	'		'
AFS Fair Value, Less than 12 months	72,437		100,396
AFS Unrealized Losses, Less than 12 month	-1,962	[1]	-2,950	[1]
AFS Fair Value, 12 months or longer	7,466		6,298
AFS Unrealized Losses, 12 months or longer	-294	[1]	-516	[1]
AFS Fixed Income Securities [Member] | Residential Mortgage Backed Securities (RMBS) [Member]	'		'
AFS Fair Value, Less than 12 months	221,314		268,943
AFS Unrealized Losses, Less than 12 month	-7,294	[1]	-10,031	[1]
AFS Fair Value, 12 months or longer	4,823		2,670
AFS Unrealized Losses, 12 months or longer	-459	[1]	-260	[1]
Equity Securities [Member]	'		'
AFS Fair Value, Less than 12 months	1,938		1,124
AFS Unrealized Losses, Less than 12 month	-117	[1]	-96	[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 $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
	Securities	Securities
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities in an unrealized/unrecognized loss position	466	557
Unrealized Unrecognized Loss	$31,395,000	$52,011,000
Unrealized Unrecognized Losses Period Improvement	20,600,000	'
Securities In Unrealized Unrecognized Loss Position For More Than Twelve Months	2,700,000	2,900,000
Eighty Percent to Ninety-Nine Percent [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities in an unrealized/unrecognized loss position	466	556
Unrealized Unrecognized Loss	31,395,000	51,835,000
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	176,000
Forty Percent to Fifty-Nine Percent [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Number of securities in an unrealized/unrecognized loss position	0	0
Unrealized Unrecognized Loss	0	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]	'	'
Decrease of Yield on 10-year U.S. Treasury Note	31	'

Investments_HTM_Fixed_Income_S

Investments (HTM Fixed Income Securities by Contractual Maturity) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments [Abstract]	'	'
Due in one year or less carrying value	$80,337	'
Due after one year through five years carrying value	270,608	'
Due after five years through 10 years carrying value	31,111	'
Total HTM fixed income securities carrying value	382,056	392,879
Due in one year or less fair value	81,332	'
Due after one year through five years fair value	287,045	'
Due after five years through 10 years fair value	35,159	'
Total HTM fixed income securities fair value	$403,536	$416,981

Investments_AFS_Fixed_Income_s

Investments (AFS Fixed Income securities by Contractual Maturity) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Investments [Abstract]	'	'
Due in one year or less fair value	$425,744	'
Due after one year through five years fair value	1,991,515	'
Due after five years through 10 years fair value	1,345,666	'
Due after 10 years fair value	52,928	'
Total AFS fixed income securities	$3,815,853	$3,715,536

Investments_Other_Investment_P

Investments (Other Investment Portfolio by Strategy and the Remaining Commitment Amount Associated With Each Strategy) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Carrying Value	$106,720	$107,875
Other Investments [Member]	'	'
Carrying Value	106,720	107,875
Remaining Commitment	52,556	'
Alternative Investments [Member]	'	'
Carrying Value	105,150	106,211
Remaining Commitment	51,959	'
Secondary Private Equity Member | Alternative Investments [Member]	'	'
Carrying Value	23,595	25,618
Remaining Commitment	6,479	'
Private Equity [Member] | Alternative Investments [Member]	'	'
Carrying Value	21,117	20,192
Remaining Commitment	9,959	'
Energy Power Generation [Member] | Alternative Investments [Member]	'	'
Carrying Value	17,978	17,361
Remaining Commitment	6,984	'
Mezzanine Financing [Member] | Alternative Investments [Member]	'	'
Carrying Value	13,831	12,738
Remaining Commitment	15,038	'
Distressed Debt [Member] | Alternative Investments [Member]	'	'
Carrying Value	10,882	11,579
Remaining Commitment	2,971	'
Real Estate Strategy [Member] | Alternative Investments [Member]	'	'
Carrying Value	10,728	11,698
Remaining Commitment	10,178	'
Venture Capital [Member] | Alternative Investments [Member]	'	'
Carrying Value	7,019	7,025
Remaining Commitment	350	'
Other Securities [Member]	'	'
Carrying Value	1,570	1,664
Remaining Commitment	$597	'

Investments_Aggregated_Income_

Investments (Aggregated Income Statement Summarized Financial Information for Partnerhips in our Alternative Investment Portfolio) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
			Alternative Investments [Member]	Alternative Investments [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	'	'	'	'	$65,100,000	$204,800,000
Realized gains	'	'	'	'	63,300,000	593,400,000
Net change in unrealized appreciation (depreciation)	'	'	'	'	505,900,000	-417,500,000
Net income	'	'	'	'	634,300,000	380,700,000
Net investment income earned	$35,534,000	$32,870,000	$5,200,000	$3,600,000	'	'

Investments_Investments_Pledge

Investments (Investments Pledged as Collateral) (Details) (USD $)	Mar. 31, 2014
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'
Fixed income securities pledged at carrying value	$61.80
Outstanding borrowing with the Federal Home Loan Bank of Indianapolis	58
Carrying value bonds on deposit with various State and Regulatory agencies	26.2
Short-term Investments [Member]	'
Schedule of Available-for-sale Securities [Line Items]	'
Securities pledged as collateral	0.2
Fixed Income Securities [Member]	'
Schedule of Available-for-sale Securities [Line Items]	'
Securities pledged as collateral	$22.30

Investments_Net_Investment_Inc

Investments (Net Investment Income) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net Investment Income [Line Items]	'	'
Net investment income earned	$35,534	$32,870
Fixed Income Securities [Member]	'	'
Net Investment Income [Line Items]	'	'
Net investment income earned	31,028	30,089
Equity Securities [Member]	'	'
Net Investment Income [Line Items]	'	'
Net investment income earned	1,449	1,207
Short-term Investments [Member]	'	'
Net Investment Income [Line Items]	'	'
Net investment income earned	19	52
Other Investments [Member]	'	'
Net Investment Income [Line Items]	'	'
Net investment income earned	5,218	3,602
Investment Expenses [Member]	'	'
Net Investment Income [Line Items]	'	'
Net investment income earned	($2,180)	($2,080)

Investments_OTTI_by_Asset_Type

Investments (OTTI by Asset Type) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
OTTI Losses Gross	$963	$1,919
Other-than-temporary impairments on fixed maturity securities recognized in other comprehensive income	0	-30
OTTI Losses Recognized in Earnings	963	1,949
Equity Securities [Member]	'	'
OTTI Losses Gross	963	217
Other-than-temporary impairments on fixed maturity securities recognized in other comprehensive income	0	0
OTTI Losses Recognized in Earnings	963	217
Other Investments [Member]	'	'
OTTI Losses Gross	'	1,724
Other-than-temporary impairments on fixed maturity securities recognized in other comprehensive income	'	0
OTTI Losses Recognized in Earnings	'	1,724
AFS Fixed Income Securities [Member]	'	'
OTTI Losses Gross	'	-22
Other-than-temporary impairments on fixed maturity securities recognized in other comprehensive income	'	-30
OTTI Losses Recognized in Earnings	'	8
AFS Fixed Income Securities [Member] | Residential Mortgage Backed Securities (RMBS) [Member]	'	'
OTTI Losses Gross	'	-22
Other-than-temporary impairments on fixed maturity securities recognized in other comprehensive income	'	-30
OTTI Losses Recognized in Earnings	'	8
Total AFS Securities [Member]	'	'
OTTI Losses Gross	963	195
Other-than-temporary impairments on fixed maturity securities recognized in other comprehensive income	0	-30
OTTI Losses Recognized in Earnings	$963	$225

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
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Investments [Abstract]	'	'
Balance, beginning of period	$7,488	$7,477
Addition for the amount related to credit loss for which an OTTI was not previously recognized	0	0
Reductions for securities sold during the period	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
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
Additional increases to the amount related to credit loss for which an OTTI was previously recognized	0	9
Accretion of credit loss impairments previously recognized due to increase in cash flows expected to be collected	0	0
Balance, end of period	$7,488	$7,486

Investments_Components_Of_Net_

Investments (Components Of Net Realized Gains, Excluding OTTI Charges) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'
HTM fixed income securities Gains	$0	$0
HTM fixed income securities Losses	-11,000	-37,000
Other investments Gains	0	0
Other Investments Losses	0	-860,000
Total other net realized investment gains	8,181,000	5,304,000
Total OTTI charges recognized in earnings	-963,000	-1,949,000
Total net realized gains	7,218,000	3,355,000
Proceeds From Sale Of Available For Sale Securities	62,800,000	6,900,000
Fixed Income Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
AFS securities Gains	158,000	951,000
AFS securities Losses	-112,000	-253,000
Equity Securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
AFS securities Gains	8,317,000	5,671,000
AFS securities Losses	($171,000)	($168,000)

Fair_Value_Measurements_Carryi

Fair Value Measurements (Carrying Value and Estimated Fair Value of Financial Instruments) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Held-to-maturity Securities	$382,056	$392,879
Available-for-sale Securities	3,815,853	3,715,536
Equity securities, AFS	197,687	192,771
Short-term investments	137,733	174,251
Notes payable	392,420	392,414
Carrying Amount [Member]	'	'
Held-to-maturity Securities	382,056	392,879
Available-for-sale Securities	3,815,853	3,715,536
Equity securities, AFS	197,687	192,771
Short-term investments	137,733	174,251
Notes payable	392,420	392,414
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 Twenty Five Percent Senior Notes [Member]	'	'
Notes payable	49,917	49,916
Carrying Amount [Member] | Six Point Seventy Percent Senior Notes [Member]	'	'
Notes payable	99,503	99,498
Carrying Amount [Member] | Five Point Eight Hundred Seventy Five Senior Notes [Member]	'	'
Notes payable	185,000	185,000
Fair Value [Member]	'	'
Held-to-maturity Securities	403,536	416,981
Available-for-sale Securities	3,815,853	3,715,536
Equity securities, AFS	197,687	192,771
Short-term investments	137,733	174,251
Notes payable	379,660	354,010
Fair Value [Member] | Two Point Ninety Percent Borrowing From Federal Home Loan Bank [Member]	'	'
Notes payable	13,243	13,319
Fair Value [Member] | One Point Twenty Five Percent Borrowing From Federal Home Loan Bank [Member]	'	'
Notes payable	45,226	45,259
Fair Value [Member] | Seven Point Twenty Five Percent Senior Notes [Member]	'	'
Notes payable	53,065	50,887
Fair Value [Member] | Six Point Seventy Percent Senior Notes [Member]	'	'
Notes payable	102,810	98,247
Fair Value [Member] | Five Point Eight Hundred Seventy Five Senior Notes [Member]	'	'
Notes payable	$165,316	$146,298

Fair_Value_Measurements_Quanti

Fair Value Measurements (Quantitative Disclosures of Fair Value Assets) (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Available-for-sale Securities, Debt Securities	$3,815,853		$3,715,536
Equity securities, AFS	197,687		192,771
Total AFS securities	4,013,540		3,908,307
Short-term investments	137,733		174,251
Fair Value [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	3,815,853		3,715,536
Equity securities, AFS	197,687		192,771
Total AFS securities	4,013,540		3,908,307
Short-term investments	137,733		174,251
Total assets measured at fair value	4,151,273		4,082,558
Fair Value [Member] | US Government and Government Agencies and Authorities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	171,065		173,375
Fair Value [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	32,421		30,615
Fair Value [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	979,167		951,624
Fair Value [Member] | Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	1,815,698		1,734,883
Fair Value [Member] | Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	131,934		140,896
Fair Value [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	174,816		171,284
Fair Value [Member] | Residential Mortgage Backed Securities (RMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	510,752		512,859
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	51,796	[1]	52,153	[1]
Equity securities, AFS	194,787	[1]	189,871	[1]
Total AFS securities	246,583	[1]	242,024	[1]
Short-term investments	137,733	[1]	174,251	[1]
Total assets measured at fair value	384,316	[1]	416,275	[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 Securities, Debt Securities	51,796	[1]	52,153	[1]
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	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 Securities, Debt Securities	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 Securities, Debt Securities	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 Securities, Debt Securities	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 Securities, Debt Securities	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 Securities, Debt Securities	0	[1]	0	[1]
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	3,764,057	[1]	3,663,383	[1]
Equity securities, AFS	0	[1]	0	[1]
Total AFS securities	3,764,057	[1]	3,663,383	[1]
Short-term investments	0	[1]	0	[1]
Total assets measured at fair value	3,764,057	[1]	3,663,383	[1]
Significant Other Observable Inputs (Level 2) [Member] | US Government and Government Agencies and Authorities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	119,269	[1]	121,222	[1]
Significant Other Observable Inputs (Level 2) [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	32,421	[1]	30,615	[1]
Significant Other Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	979,167	[1]	951,624	[1]
Significant Other Observable Inputs (Level 2) [Member] | Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	1,815,698	[1]	1,734,883	[1]
Significant Other Observable Inputs (Level 2) [Member] | Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	131,934	[1]	140,896	[1]
Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	174,816	[1]	171,284	[1]
Significant Other Observable Inputs (Level 2) [Member] | Residential Mortgage Backed Securities (RMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	510,752	[1]	512,859	[1]
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	0		0
Equity securities, AFS	2,900		2,900
Total AFS securities	2,900		2,900
Short-term investments	0		0
Total assets measured at fair value	2,900		2,900
Significant Unobservable Inputs (Level 3) [Member] | US Government and Government Agencies and Authorities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	0		0
Significant Unobservable Inputs (Level 3) [Member] | Foreign Government [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	0		0
Significant Unobservable Inputs (Level 3) [Member] | Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	0		0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	0		0
Significant Unobservable Inputs (Level 3) [Member] | Asset-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	0		0
Significant Unobservable Inputs (Level 3) [Member] | Commercial Mortgage-backed Securities (CMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	0		0
Significant Unobservable Inputs (Level 3) [Member] | Residential Mortgage Backed Securities (RMBS) [Member] | Fair Value, Measurements, Recurring [Member]	'		'
Available-for-sale Securities, Debt Securities	$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 $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'
Fair value, Beginning balance	$42,277
Total net (losses) gains for the period included in OCI	4,089	[1]
Total net (losses) gains for the period included in net income	-1,195	[2],[3]
Purchases	0
Sales	0
Issuances	0
Settlements	-4,660
Transfers into Level 3	0
Transfers out of Level 3	-37,611
Fair value, Ending balance	2,900
Equity Securities [Member]	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'
Fair value, Beginning balance	3,607
Total net (losses) gains for the period included in OCI	3,935	[1]
Total net (losses) gains for the period included in net income	0	[2],[3]
Purchases	0
Sales	0
Issuances	0
Settlements	0
Transfers into Level 3	0
Transfers out of Level 3	-4,642
Fair value, Ending balance	2,900
AFS Fixed Income 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
Total net (losses) gains for the period included in OCI	-537	[1]
Total net (losses) gains for the period included in net income	-76	[2],[3]
Purchases	0
Sales	0
Issuances	0
Settlements	-1,847
Transfers into Level 3	0
Transfers out of Level 3	-17,329
Fair value, Ending balance	0
AFS Fixed Income Securities [Member] | Corporate Securities [Member]	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'
Fair value, Beginning balance	2,946
Total net (losses) gains for the period included in OCI	-7	[1]
Total net (losses) gains for the period included in net income	0	[2],[3]
Purchases	0
Sales	0
Issuances	0
Settlements	-168
Transfers into Level 3	0
Transfers out of Level 3	-2,771
Fair value, Ending balance	0
AFS Fixed Income Securities [Member] | Asset-backed Securities [Member]	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'
Fair value, Beginning balance	6,068
Total net (losses) gains for the period included in OCI	-74	[1]
Total net (losses) gains for the period included in net income	0	[2],[3]
Purchases	0
Sales	0
Issuances	0
Settlements	0
Transfers into Level 3	0
Transfers out of Level 3	-5,994
Fair value, Ending balance	0
AFS Fixed Income 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
Total net (losses) gains for the period included in OCI	772	[1]
Total net (losses) gains for the period included in net income	361	[2],[3]
Purchases	0
Sales	0
Issuances	0
Settlements	-2,420
Transfers into Level 3	0
Transfers out of Level 3	-5,875
Fair value, Ending balance	0
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
Total net (losses) gains for the period included in OCI	0	[1]
Total net (losses) gains for the period included in net income	-1,480	[2],[3]
Purchases	0
Sales	0
Issuances	0
Settlements	-225
Transfers into Level 3	0
Transfers out of Level 3	-1,000
Fair value, Ending balance	0
Fair Value, Inputs, Level 3 [Member] | AFS Fixed Income Securities [Member]	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'
Transfers out of Level 3	($32,000)
[1]	Amounts are reported in “Unrealized holding (losses) gains arising during period” on the Consolidated Statements of Comprehensive Income in our 2013 Annual Report.
[2]	Amounts are reported in “Net realized gains” for realized gains and losses and “Net investment income earned” for amortization of securities on the Consolidated Statements of Income in our 2013 Annual Report.
[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 Consolidated Statements of Income in our 2013 Annual Report.

Fair_Value_Measurements_Quanti1

Fair Value Measurements (Quantitative Information of Our Financial Assets and Liabilities That Were Disclosed at Fair Value) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	$382,056	$392,879
Notes payable	392,420	392,414
Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	403,536	416,981
Notes payable	379,660	354,010
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	165,316	146,298
Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	403,536	416,981
Notes payable	214,344	207,712
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
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	5,552	5,591
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	5,552	5,591
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	364,307	369,756
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	364,307	369,756
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	24,464	30,274
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	24,464	30,274
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	0
Asset-backed Securities [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Held-to-maturity Securities	3,366	3,415
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	3,366	3,415
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	0	0
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	5,847	7,945
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	5,847	7,945
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	13,243	13,319
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	13,243	13,319
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	45,226	45,259
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	45,226	45,259
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 Twenty Five Percent Senior Notes [Member] | Fair Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Notes payable	53,065	50,887
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	53,065	50,887
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
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	102,810	98,247
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	0
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	102,810	98,247
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
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	165,316	146,298
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	165,316	146,298
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	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	$0

Reinsurance_List_of_Direct_Ass

Reinsurance (List of Direct, Assumed, and Ceded Reinsurance Amounts) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Premiums written:	'	'
Direct	$557,891	$528,816
Assumed	7,850	8,482
Ceded premiums written	-88,991	-87,174
Net	476,750	450,124
Premiums earned:	'	'
Direct	536,700	494,066
Assumed	10,185	12,463
Ceded premiums earned	-90,390	-85,589
Net	456,495	420,940
Loss and loss expense incurred:	'	'
Direct	358,349	365,646
Assumed	7,479	9,074
Ceded loss and loss expense incurred	-45,282	-104,871
Net	$320,546	$269,849
Number of insurance subsidiaries	10	'
Percentage of NFIP claims ceded by federal government	100.00%	'

Reinsurance_Ceded_Premiums_and

Reinsurance (Ceded Premiums and Losses Related to Flood Operations) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Ceded premiums written	($88,991)	($87,174)
Ceded premiums earned	-90,390	-85,589
Ceded loss and loss expense incurred	-45,282	-104,871
National Flood Insurance Program [Member]	'	'
Ceded premiums written	-57,303	-56,707
Ceded premiums earned	-58,286	-55,327
Ceded loss and loss expense incurred	($7,379)	($76,176)

Segment_Information_Narrative_

Segment Information Narrative (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Number of Operating Segments	3	'
Gross premiums of self-insured pooled group renewal book of business sold	$38,000,000	'
Proceeds from sale of renewal rights	$8,000,000	$0

Segment_Information_Revenue_Fr

Segment Information (Revenue From Continuing Operations by Segment) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	$456,495	$420,940
Other income	9,824	2,784
Net investment income	35,534	32,870
Net realized investment gains	7,218	3,355
Total investment revenues	42,752	36,225
Total all segments	509,066	459,885
Total revenues	509,071	459,949
Commercial Automobile [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	82,216	74,347
Workers Compensation [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	69,413	66,084
General Liability [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	108,818	97,703
Commercial Property [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	60,186	53,415
Business Owners' Policies [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	20,869	18,540
Bonds Segment [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	4,756	4,764
Other Commercial [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	3,183	2,992
Total Standard Commercial Lines [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	349,441	317,845
Personal Automobile [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	38,226	38,393
Homeowners [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	33,298	31,135
Other Personal [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	3,294	3,508
Total standard Personal Lines [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	74,818	73,036
Total Standard Insurance Operations [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	424,259	390,881
Total insurance operations revenues	434,078	393,601
Miscellaneous Income [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Other income	9,819	2,720
Excess And Surplus Operations [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Total net premiums earned	32,236	30,059
Other Income [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Other income	$5	$64

Segment_Information_Income_Fro

Segment Information (Income From Continuing Operations, Before Federal Income Tax) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]	'	'
Net investment income	$35,534	$32,870
Net realized investment gains	7,218	3,355
Investment income, before federal income tax	42,752	36,225
Tax on investment income	11,575	9,205
Total investment income, after federal income tax	31,177	27,020
Total Standard Commercial Lines [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Underwriting (loss) gain, before federal income tax	-3,630	6,102
Total standard Personal Lines [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Underwriting (loss) gain, before federal income tax	-2,360	5,973
Total Standard Insurance Operations [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Underwriting (loss) gain, before federal income tax	-5,990	12,075
GAAP combined ratio	101.40%	96.90%
Statutory combined ratio	101.10%	96.80%
Excess And Surplus Operations [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Underwriting (loss) gain, before federal income tax	$975	$86
GAAP combined ratio	97.00%	99.70%
Statutory combined ratio	97.90%	98.20%

Segment_Information_Reconcilia

Segment Information (Reconciliation of Segment Results to Income from Continuing Operations, before Federal Income Tax (Details)) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]	'	'
Investment income, before federal income tax	$42,752	$36,225
Total all segments	37,737	48,386
Interest expense	-5,561	-5,831
General corporate and other expenses	-7,092	-13,687
Income from continuing operations, before federal income tax	25,084	28,868
Total Standard Insurance Operations [Member]	'	'
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]	'	'
Underwriting (loss) gain, before federal income tax	-5,990	12,075
Excess And Surplus Operations [Member]	'	'
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]	'	'
Underwriting (loss) gain, before federal income tax	$975	$86

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
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Defined Benefit Plans And Other Postretirement Benefit Plans [Line Items]	'	'
Curtailment expense	$0	$16
Retirement Income Plan [Member]	'	'
Defined Benefit Plans And Other Postretirement Benefit Plans [Line Items]	'	'
Service cost	1,627	2,449
Interest cost	3,254	3,303
Expected return on plan assets	-3,919	-3,848
Amortization of unrecognized prior service cost	0	10
Amortization of unrecognized net actuarial loss	367	1,822
Curtailment expense	0	16
Total net periodic cost	1,329	3,752
Retirement Life Plan [Member]	'	'
Defined Benefit Plans And Other Postretirement Benefit Plans [Line Items]	'	'
Service cost	0	0
Interest cost	73	70
Expected return on plan assets	0	0
Amortization of unrecognized prior service cost	0	0
Amortization of unrecognized net actuarial loss	13	18
Curtailment expense	0	0
Total net periodic cost	$86	$88

Retirement_Plans_WeightedAvera

Retirement Plans (Weighted-Average Expense Assumptions) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Retirement Income Plan [Member]	'	'
Defined Benefit Plans And Other Postretirement Benefit Plans [Line Items]	'	'
Discount rate	5.16%	4.42%
Expected return on plan assets	6.92%	7.40%
Rate of compensation increase	4.00%	4.00%
Estimated contribution from the employer	$2.70	'
Retirement Life Plan [Member]	'	'
Defined Benefit Plans And Other Postretirement Benefit Plans [Line Items]	'	'
Discount rate	4.85%	4.42%
Expected return on plan assets	0.00%	0.00%
Rate of compensation increase	0.00%	0.00%
Scenario, Forecast [Member] | Retirement Income Plan [Member]	'	'
Defined Benefit Plans And Other Postretirement Benefit Plans [Line Items]	'	'
Estimated contribution from the employer	$9.80	'

Comprehensive_Income_Component

Comprehensive Income (Components of Comprehensive Income-Gross and Net of Tax) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net income, Gross	$25,084	$27,333
Unrealized holding gains during the period, Gross	32,964	3,684
Non-credit portion of other-than-temporary impairment losses recognized in other comprehensive income, Gross	'	30
HTM securties, Gross	-456	-717
Realized gains on AFS securities, Gross	-7,229	-5,976
Net unrealized gains (losses), Gross	25,279	-2,972
Amount reclassified into Net Income: Net actuarial loss, Gross	380	1,840
Amount reclassified into Net Income: Prior service cost, Gross	0	10
Amount reclassified into Net Income: Curtailment expense, Gross	'	16
Defined pension and other post-retirement benefit plans, gross	380	45,866
Comprehensive income, Gross	50,743	70,227
Net income, Tax	7,110	6,025
Unrealized holding gains (losses) during the period, Tax	11,538	1,290
Non-credit portion of other-than-temporary impairment losses recognized in other comprehensive income, Tax	'	10
HTM securities, Tax	-160	-251
Realized gains on AFS securities, Tax	-2,530	-2,092
Net unrealized gains (losses), Tax	8,848	-1,040
Amount reclassified into Net Income: Net actuarial loss, Tax	133	644
Amount reclassified into Net Income: Prior service cost, Tax	0	4
Amount reclassified into Net Income: Curtailment expense, tax	'	5
Defined pension and other post-retirement benefit plans, tax	133	16,053
Comprehensive income, Tax	16,091	21,038
Net income	17,974	21,308
Unrealized holding gains arising during period	21,426	2,394
Non-credit portion of other-than-temporary impairments recognized in other comprehensive income	0	20
HTM Securities	-296	-466
Realized gains on available for sale securities	-4,699	-3,884
Net unrealized gains (losses) on Investment Securities	16,431	-1,932
Amount reclassified into Net Income: Net actuarial loss	247	1,196
Amount reclassified into Net Income: Prior service cost	0	6
Amount reclassified into Net Income: Curtailment expense	0	11
Total defined benefit pension and post-retirement plans	247	29,813
Comprehensive income	34,652	49,189
Accumulated Other-than-Temporary Impairment [Member]	'	'
Non-credit OTTI, Gross	'	7
Non-credit OTTI, Tax	'	3
Amounts reclassified from AOCI	0	4
Other Comprehensive Income, Net of Tax	0	'
Accumulated other comprehensive income [Member]	'	'
Other comprehensive loss, Gross	25,659	42,894
Other comprehensive income, Tax	8,981	15,013
Amounts reclassified from AOCI	-4,748	'
Other Comprehensive Income, Net of Tax	16,678	27,881
Accumulated Defined Benefit Plans Adjustment [Member]	'	'
Net actuarial gain, Gross	'	44,000
Net actuarial gain, Tax	'	15,400
Net actuarial gain	0	28,600
Total defined benefit pension and post-retirement plans	$247	'

Comprehensive_Income_Component1

Comprehensive Income (Components of Accumulated Other Comprehensive Income) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Beginning Balance,December 31, 2013	$24,851	'
Amounts reclassified from AOCI, HTM Related	-296	-466
Amounts reclassified from AOCI, All Other	-4,699	-3,884
Other Comprehensive Income, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	247	29,813
Ending Balance, March 31, 2014	41,529	'
Available-for-sale Securities [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Beginning Balance,December 31, 2013	51,635	'
OCI before reclassifications	21,426	'
Other comprehensive income	16,727	'
Ending Balance, March 31, 2014	68,362	'
Investments [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Beginning Balance,December 31, 2013	51,503	'
OCI before reclassifications	21,426	'
Amounts reclassified from AOCI	-4,995	'
Other comprehensive income	16,431	'
Ending Balance, March 31, 2014	67,934	'
Accumulated Other-than-Temporary Impairment [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Beginning Balance,December 31, 2013	-1,599	'
OCI before reclassifications	0	'
Amounts reclassified from AOCI	0	4
Other comprehensive income	0	'
Ending Balance, March 31, 2014	-1,599	'
Accumulated Net Unrealized Investment Gain (Loss) [Member] | Held To Maturity Fixed Income Securities [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Beginning Balance,December 31, 2013	1,467	'
OCI before reclassifications	0	'
Other comprehensive income	-296	'
Ending Balance, March 31, 2014	1,171	'
Accumulated Defined Benefit Plans Adjustment [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Beginning Balance,December 31, 2013	-26,652	'
OCI before reclassifications, Defined Benefit Pension and Post Retirement Plans	0	28,600
Other Comprehensive Income, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	247	'
Ending Balance, March 31, 2014	-26,405	'
Accumulated other comprehensive income [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Beginning Balance,December 31, 2013	24,851	'
OCI before reclassifications	21,426	'
Amounts reclassified from AOCI	-4,748	'
Other comprehensive income	16,678	27,881
Ending Balance, March 31, 2014	$41,529	'

Comprehensive_Income_Reclassif

Comprehensive Income (Reclassification out of AOCI) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Total HTM Related, Tax	$160	$251
Amounts reclassified from AOCI, HTM Related	-296	-466
Realized gains on AFS disposals and OTTI	-7,229	-5,976
Total unrealized gains and losses on AFS, Tax	2,530	2,092
Realized gains on available for sale securities	-4,699	-3,884
Amount reclassified into Net Income: Net actuarial loss, Gross	380	1,840
Total defined benefit pension and post-retirement life, Gross	380	45,866
Total defined benefit pension and post-retirement life,Tax	-133	-16,053
Total defined benefit pension and post-retirement plans	247	29,813
Accumulated Other-than-Temporary Impairment [Member]	'	'
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	'
Net Realized Gains [Member]	'	'
Unrealized gains and losses on HTM disposals	24	'
Realized gains on AFS disposals and OTTI	-7,229	'
Net Investment Income Earned [Member]	'	'
Amortization of net unrealized gains on HTM securities	-480	'
Income From Continuing Operations Before Federal Income Tax [Member]	'	'
Amortization of net unrealized gains on HTM securities	-456	'
Realized gains on AFS disposals and OTTI	-7,229	'
Total defined benefit pension and post-retirement life, Gross	380	'
Total Federal Income Tax Expense [Member]	'	'
Total HTM Related, Tax	160	'
Total unrealized gains and losses on AFS, Tax	2,530	'
Total defined benefit pension and post-retirement life,Tax	-133	'
Net Income Financial Statement [Member]	'	'
Amounts reclassified from AOCI, HTM Related	-296	'
Realized gains on available for sale securities	-4,699	'
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	-4,748	'
Net Income Financial Statement [Member] | Accumulated Defined Benefit Plans Adjustment [Member]	'	'
Total defined benefit pension and post-retirement plans	247	'
Loss and loss expense incurred [Member]	'	'
Amount reclassified into Net Income: Net actuarial loss, Gross	87	'
Policy acquisition costs [Member]	'	'
Amount reclassified into Net Income: Net actuarial loss, Gross	$293	'