Stancorp Financial (SFG) 10-K 26 Feb 14 2013 FY Annual report Financial data

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 14, 2014	Jun. 28, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Document Period End Date	31-Dec-13	'	'
Amendment Flag	'false	'	'
Entity Registrant Name	'STANCORP FINANCIAL GROUP INC	'	'
Entity Central Index Key	'0001079577	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Current Fiscal Year End Date	'--12-31	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Common Stock, Shares Outstanding	'	43,715,485	'
Entity Public Float	'	'	$2,165,901,629
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Closing Stock Price	'	'	$49.41

Consolidated_Statements_Of_Inc

Consolidated Statements Of Income And Comprehensive Income (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Revenues:	'	'	'
Premiums	$2,124.30	$2,163.90	$2,153.30
Administrative fees	121.6	114.7	115.5
Net investment income	629.9	628.5	612.8
Net capital losses:	'	'	'
Total other-than-temporary impairment losses on fixed maturity securities-available-for-sale	-1.1	-3.2	-1.8
All other net capital losses	-14.6	-5.5	-5.1
Total net capital losses	-15.7	-8.7	-6.9
Total revenues	2,860.10	2,898.40	2,874.70
Benefits and expenses:	'	'	'
Benefits to policyholders	1,655.40	1,793	1,771.20
Interest credited	176.4	171.3	161
Operating expenses	442.6	470.5	471.2
Commissions and bonuses	207.9	203.7	218.7
Premium taxes	35.3	37.5	36.7
Interest expense	34.4	39.9	38.9
Net increase in deferred acquisition costs, value of business acquired and other intangible assets	-4.9	-0.9	-14.5
Total benefits and expenses	2,547.10	2,715	2,683.20
Income before income taxes	313	183.4	191.5
Income taxes	84.5	44.9	54.8
Net income	$228.50	$138.50	$136.70
Net income per common share:	'	'	'
Basic	$5.16	$3.13	$3.05
Diluted	$5.13	$3.12	$3.04
Weighted-average common shares outstanding:	'	'	'
Basic	44,243,364	44,283,771	44,876,650
Diluted weighted-average common shares outstanding	44,527,405	44,359,891	45,016,070

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
StatementOfIncomeAndComprehensiveIncomeAbstract	'		'		'
Net income	$228.50		$138.50		$136.70
Unrealized gains on securities-available-for-sale:	'		'		'
Net unrealized capital gains on securities-available-for-sale	-205.3	[1]	71.4	[1]	103.4	[1]
Reclassification adjustment for net capital (gains) losses included in net income, net CF	-4.5	[2]	-3.6	[2]	-5.9	[2]
Employee benefit plans:	'		'		'
Prior service (cost) credit and net (losses) gains arising during the period, net	41.2	[3]	0	[3]	-26.6	[3]
Reclassification adjustment for amortization to net periodic pension cost, net	-6	[4]	6.4	[4]	3.3	[4]
Total other comprehensive income, net of tax	-174.6		74.2		74.2
Comprehensive income	$53.90		$212.70		$210.90
[1]	Net of tax benefit of $111.1 million and tax expenses of $38.3 million and $55.9 million for 2013, 2012 and 2011, respectively.
[2]	Net of tax benefits of $3.1 million, $2.2 million and $3.2 million for 2013, 2012 and 2011, respectively.
[3]	* Assumption for rate of compensation increase was not applicable in determining benefit obligations for 2013, 2012 and 2011or net periodic benefit cost in 2013 and 2012 due to curtailment of group term life insurance benefit as of December 31, 2011.
[4]	Net of tax benefit of $3.2 million and tax expenses of $3.4 million and $1.7 million for 2013, 2012 and 2011, respectively.

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee benefit plans, tax effect:	'	'	'
Prior service credit and net losses arising during the period, tax effect	($22.20)	($0.20)	$14.30
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Recognized in Net Periodic Pension Cost, Tax Effect	-3.2	3.4	1.7
Other comprehensive income, tax effect:	'	'	'
Unrealized gains (losses) on fixed maturity securities, tax effect	-111.1	38.3	55.9
Reclassification adjustment for net capital gains included in net income, tax effect	($3.10)	($2.20)	($3.20)

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
ASSETS	'	'
Fixed maturity securities-available-for-sale (amortized cost of $6,811.9 and $6,517.7)	$7,120.50	$7,190.70
Commercial mortgage loans, net	5,405.10	5,267.40
Real estate, net	65.7	95.5
Other invested assets	196.5	175.5
Total investments	12,787.80	12,729.10
Cash and cash equivalents	379.3	160.7
Premiums and other receivables	118.2	123
Accrued investment income	106.8	109.3
Amounts recoverable from reinsurers	988.1	972.4
Deferred acquisition costs, value of business acquired and other intangible assets, net	371.3	346.5
Goodwill	36	36
Property and equipment, net	84.7	90.7
Other assets	127.9	69.3
Separate account assets	6,393.20	5,154.30
Total assets	21,393.30	19,791.30
Liabilities:	'	'
Future policy benefits and claims	5,846.90	5,843.20
Other policyholder funds	6,051.60	5,531.10
Deferred tax liabilities, net	64.7	148.1
Short-term debt	1.5	1
Long-term debt	551.9	551.4
Other liabilities	330.7	393.2
Separate account liabilities	6,393.20	5,154.30
Total liabilities	19,240.50	17,622.30
Commitments and contingencies (See Note 19)	'	'
Shareholders' equity:	'	'
Preferred stock, 100,000,000 shares authorized; none issued	0	0
Common stock, no par, 300,000,000 shares authorized; 44,126,389 and 44,419,448 shares issued and outstanding at December 31, 2013 and December 31, 2012, respectively	68	89.6
Accumulated other comprehensive income	134.7	309.3
Retained earnings	1,950.10	1,770.10
Total shareholders' equity	2,152.80	2,169
Total liabilities and shareholders' equity	$21,393.30	$19,791.30

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, except Share data, unless otherwise specified
Consolidated Balance Sheets [Abstract]	'	'
Amortized cost of fixed maturity securities-available-for-sale	$6,811.90	$6,517.70
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	44,126,389	44,419,448
Common Stock, par value	$0	$0

Consolidated_Statements_Of_Cha

Consolidated Statements Of Changes In Shareholders' Equity (USD $)	Total	Common Stock [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]
In Millions, except Share data, unless otherwise specified
Balance at Dec. 31, 2010	$1,894.60	$158.20	$160.90	$1,575.50
Balance, shares at Dec. 31, 2010	'	46,159,387	'	'
Changes in Shareholders' Equity	'	'	'	'
Net income	136.7	'	'	136.7
Other comprehensive income, net of tax	74.2	'	74.2	'
Common stock:	'	'	'	'
Repurchased	-90.3	-90.3	'	'
Shares repurchased	'	-2,180,100	'	'
Issued under share-based compensation plans, net	14.5	14.5	'	'
Issued under share-based compensation plans net, shares	'	289,572	'	'
Dividends declared on common stock	-39.3	'	'	-39.3
Balance at Dec. 31, 2011	1,990.40	82.4	235.1	1,672.90
Balance, shares at Dec. 31, 2011	'	44,268,859	'	'
Changes in Shareholders' Equity	'	'	'	'
Net income	138.5	'	'	138.5
Other comprehensive income, net of tax	74.2	'	74.2	'
Common stock:	'	'	'	'
Repurchased	-10	-10	'	'
Shares repurchased	'	-279,700	'	'
Issued under share-based compensation plans, net	17.2	17.2	'	'
Issued under share-based compensation plans net, shares	'	430,289	'	'
Dividends declared on common stock	-41.3	'	'	-41.3
Balance at Dec. 31, 2012	2,169	89.6	309.3	1,770.10
Balance, shares at Dec. 31, 2012	'	44,419,448	'	'
Changes in Shareholders' Equity	'	'	'	'
Net income	228.5	'	'	228.5
Other comprehensive income, net of tax	-174.6	'	-174.6	'
Common stock:	'	'	'	'
Repurchased	-82.3	-82.3	'	'
Shares repurchased	'	-1,644,488	'	'
Issued under share-based compensation plans, net	60.7	60.7	'	'
Issued under share-based compensation plans net, shares	'	1,351,429	'	'
Dividends declared on common stock	-48.5	'	'	-48.5
Balance at Dec. 31, 2013	$2,152.80	$68	$134.70	$1,950.10
Balance, shares at Dec. 31, 2013	'	44,126,389	'	'

Consolidated_Statements_Of_Cha1

Consolidated Statements Of Changes In Shareholders' Equity (Parentheticals) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Consolidated Statements Of Changes In Shareholders' Equity [Abstract]	'	'	'
Dividend per share	$1.10	$0.93	$0.89

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating:	'	'	'
Net income	$228.50	$138.50	$136.70
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'
Net realized capital losses	15.7	8.7	6.9
Depreciation and amortization	112.9	117	120.5
Deferral of acquisition costs, value of business acquired and other intangible assets, net	-76.9	-71.4	-81.7
Deferred income taxes	13.4	6.4	14.3
Changes in other assets and liabilities:	'	'	'
Receivables and accrued income	-8.4	-24.5	-28.3
Future policy benefits and claims	23.8	149.6	166.3
Other, net	-29.4	51.4	-80.6
Net cash provided by operating activities	279.6	375.7	254.1
Investing:	'	'	'
Proceeds from sale, maturity, or repayment of fixed maturity securities-available-for-sale	1,017.90	964.5	885.2
Proceeds from sale or repayment of commercial mortgage loans	1,124.60	797.6	573.8
Proceeds from sale of real estate	22	13.2	62.6
Proceeds from sale or maturity of other investments	0.2	0	0
Acquisition of fixed maturity securities-available-for-sale	-1,303.30	-1,269.40	-1,076.80
Acquisition or origination of commercial mortgage loans	-1,286.80	-1,194.60	-970.2
Acquisition of real estate	-0.9	-1.3	-5.3
Acquisition of other invested assets	-64.2	-59.7	-47
Acquisition of property and equipment, net	-13.8	-13.3	-17.7
Net cash used in investing activities	-504.3	-763	-595.4
Financing:	'	'	'
Policyholder fund deposits	2,081.50	2,008.60	1,905
Policyholder fund withdrawals	-1,561	-1,555.60	-1,454.70
Repayment of senior debt	0	-250	0
Issuance of debt, net of issuance costs	0	246.7	0
Issuance of common stock	52.6	10.9	9
Repurchases of common stock	-82.3	-10	-90.3
Dividends paid on common stock	-48.5	-41.3	-39.3
Other financing activity, net	1	0.3	-2
Net cash provided by financing activities	443.3	409.6	327.7
(Decrease) increase in cash and cash equivalents	218.6	22.3	-13.6
Cash and cash equivalents, beginning of period	160.7	138.4	152
Cash and cash equivalents, end of period	379.3	160.7	138.4
Cash paid during the period for [Abstract]	'	'	'
Interest	199.6	205.5	206.7
Income taxes	64.1	4.2	74.1
Non-cash transactions:	'	'	'
Real estate acquired through commercial mortgage loan foreclosure	11.4	16.8	22.8
Commercial mortgage loans originated on real estate sold	$1.40	$0.80	$52.20

Summary_Of_Significant_Account

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]	'
Summary Of Significant Accounting Policies	'
	NOTES TO CONSOLIDATED FINANCIAL STATEMENTS
	As used in this Form 10-K, the terms “StanCorp,” “Company,” “we,” “us” and “our” refer to StanCorp Financial Group, Inc. and its subsidiaries, unless the context otherwise requires.
	1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Organization, principles of consolidation, and basis of presentation
	StanCorp, headquartered in Portland, Oregon, is a holding company and conducts business through wholly-owned operating subsidiaries throughout the United States. Through its subsidiaries, StanCorp has the authority to underwrite insurance products in all 50 states. The Company collectively views and operates its businesses as Insurance Services and Asset Management, which both deliver distinct value to customers and shareholders. Insurance Services contains two reportable product segments, Employee Benefits and Individual Disability. See “Note 5—Segments.”
	StanCorp has the following wholly-owned operating subsidiaries: Standard Insurance Company (“Standard”), The Standard Life Insurance Company of New York, Standard Retirement Services, Inc. (“Standard Retirement Services”), StanCorp Equities, Inc. (“StanCorp Equities”), StanCorp Mortgage Investors, LLC (“StanCorp Mortgage Investors”), StanCorp Investment Advisers, Inc. (“StanCorp Investment Advisers”), StanCorp Real Estate, LLC (“StanCorp Real Estate”) and Standard Management, Inc. (“Standard Management”).
	Standard, the Company's largest subsidiary, underwrites group and individual disability insurance and annuity products, group life and accidental death and dismemberment (“AD&D”) insurance, and provides group dental and group vision insurance, absence management services and retirement plan products. Founded in 1906, Standard is domiciled in Oregon, licensed in all states except New York, and licensed in the District of Columbia and the U.S. territories of Guam and the Virgin Islands.
	The Standard Life Insurance Company of New York was organized in 2000 and is licensed to provide group long term and short term disability insurance, group life and AD&D insurance, group dental insurance and individual disability insurance in New York.
	The Standard is a service mark of StanCorp and its subsidiaries and is used as a brand mark and marketing name by Standard and The Standard Life Insurance Company of New York.
	Standard Retirement Services administers and services StanCorp's retirement plans group annuity contracts and trust products. Retirement plan products are offered in all 50 states through Standard or Standard Retirement Services.
	StanCorp Equities is a limited broker-dealer and member of the Financial Industry Regulatory Authority. As a wholesaler, StanCorp Equities activities are limited to soliciting and supporting third-party broker-dealers and investment advisers that offer or advise their retirement plan clients on using an unregistered group annuity contract or a mutual fund trust platform.
	StanCorp Mortgage Investors originates and services fixed-rate commercial mortgage loans for the investment portfolios of the Company's insurance subsidiaries. StanCorp Mortgage Investors also generates additional fee income from the origination and servicing of commercial mortgage loans participated to institutional investors.
	StanCorp Investment Advisers is a Securities and Exchange Commission (“SEC”) registered investment adviser providing performance analysis, fund selection support, model portfolios and other investment advisory, financial planning, and investment management services to its retirement plan clients, individual investors and subsidiaries of StanCorp.
	StanCorp Real Estate is a property management company that owns and manages the Hillsboro, Oregon home office properties and other properties held for investment and held for sale. StanCorp Real Estate also manages the Portland, Oregon home office properties.
	Standard Management manages certain real estate properties held for sale from time-to-time in conjunction with our real estate business.
	Standard holds interests in tax-advantaged investments. These interests do not meet the requirements for consolidation under existing accounting standards, and thus the Company's interests in the tax-advantaged investments are accounted for under the equity method of accounting. The total investment in these interests was $192.4 million and $173.0 million at December 31, 2013 and 2012 respectively.
	The consolidated financial statements include StanCorp and its subsidiaries. Intercompany balances and transactions have been eliminated on a consolidated basis.
	Use of estimates
	The Company's consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) which require management to make estimates and assumptions that affect reported amounts of assets and liabilities and disclosures of contingent assets and contingent liabilities at the dates of the financial statements and the reported amounts of revenues and expenses during the reporting periods. The estimates most susceptible to material changes due to significant judgment are those used in determining investment valuations, deferred acquisition costs (“DAC”), value of business acquired (“VOBA”) and other intangible assets, the reserves for future policy benefits and claims, pension and postretirement benefit plans and the provision for income taxes. The results of these estimates are critical because they affect the Company's profitability and may affect key indicators used to measure the Company's performance. These estimates have a material effect on our results of operations and financial condition.
	Investment Valuations
	Fixed Maturity Securities—Available-for-sale (“Fixed Maturity Securities”)
	Fixed maturity security capital gains and losses are recognized using the specific identification method. If a debt security's fair value declines below its amortized cost, the Company must assess the security's impairment to determine if the impairment is other than temporary.
	In the Company's quarterly fixed maturity security impairment analysis, management evaluates whether a decline in value of the fixed maturity security is other than temporary by considering the following factors:
	The nature of the fixed maturity security.
	The duration until maturity.
	The duration and extent the fair value has been below amortized cost.
	The financial quality of the issuer.
	Estimates regarding the issuer's ability to make the scheduled payments associated with the fixed maturity security.
	The Company's intent to sell or whether it is more likely than not we will be required to sell a fixed maturity security before recovery of the security's cost basis through the evaluation of facts and circumstances including, but not limited to, decisions to rebalance our portfolio, current cash flow needs and sales of securities to capitalize on favorable pricing.
	If it is determined an other-than-temporary impairment (“OTTI”) exists, we separate the OTTI of debt securities into an OTTI related to credit loss and an OTTI related to noncredit loss. The OTTI related to credit loss represents the portion of losses equal to the difference between the present value of expected cash flows, discounted using the pre-impairment yields, and the amortized cost basis. All other changes in value represent the OTTI related to noncredit loss. The OTTI related to credit loss is recognized in earnings in the current period, while the OTTI related to noncredit loss is deemed recoverable and is recognized in other comprehensive income. The cost basis of the fixed maturity security is permanently adjusted to reflect the credit related impairment. Once an impairment charge has been recorded, the Company continues to review the OTTI securities for further potential impairment.
	The Company will continue to evaluate our holdings; however, the Company currently expects the fair values of our investments to recover either prior to their maturity dates or upon maturity. Should the credit quality of the Company's fixed maturity securities significantly decline, there could be a material adverse effect on the Company's business, financial position, results of operations or cash flows.
	In conjunction with determining the extent of credit losses associated with debt securities, the Company utilizes certain information in order to determine the present value of expected cash flows discounted using pre-impairment yields. Some of these input factors include, but are not limited to, original scheduled contractual cash flows, current market spread information, risk-free rates, fundamentals of the industry and sector in which the issuer operates, and general market information.
	Fixed maturity securities are classified as available-for-sale and are carried at fair value on the consolidated balance sheet. See “Note 9—Fair Value” for a detailed explanation of the valuation methods the Company uses to calculate the fair value of the Company's financial instruments. Valuation adjustments for fixed maturity securities not accounted for as OTTI are reported as net increases or decreases to other comprehensive income (loss), net of tax, on the consolidated statements of comprehensive income.
	Commercial Mortgage Loans
	Commercial mortgage loans are stated at amortized cost less a loan loss allowance for probable uncollectible amounts. The commercial mortgage loan loss allowance is estimated based on evaluating known and inherent risks in the loan portfolio and consists of a general and a specific loan loss allowance.
	Impairment Evaluation
	The Company continuously monitors its commercial mortgage loan portfolio for potential impairment by evaluating the portfolio and individual loans. Key factors that are monitored are as follows:
	Loan loss experience.
	Delinquency history.
	Debt coverage ratio.
	Loan to value ratio.
	Refinancing and restructuring history.
	Request for forbearance history.
	If the analysis above indicates a loan might be impaired, it is further analyzed through the consideration of the following additional factors:
	Delinquency status.
	Foreclosure status.
	Restructuring status.
	Borrower history.
	If it is determined a loan is impaired, a specific allowance is recorded.
	General Loan Loss Allowance
	The general loan loss allowance is based on the Company's analysis of factors including changes in the size and composition of the loan portfolio, debt coverage ratios, loan to value ratios, actual loan loss experience and individual loan analysis.
	Specific Loan Loss Allowance
	An impaired commercial mortgage loan is a loan where the Company does not expect to receive contractual principal and interest in accordance with the terms of the original loan agreement. A specific allowance for losses is recorded when a loan is considered to be impaired and it is probable that all amounts due will not be collected based on the terms of the original note. The Company also holds specific loan loss allowances on certain performing commercial mortgage loans that it continues to monitor and evaluate. Impaired commercial mortgage loans without specific allowances for losses are those for which the Company has determined that it remains probable that all amounts due will be collected although the timing or nature may be outside the original contractual terms. In addition, for impaired commercial mortgage loans, the Company evaluates the cost to dispose of the underlying collateral, any significant out of pocket expenses the loan may incur and other quantitative information management has concerning the loan. Portions of loans that are deemed uncollectible are charged-off against the allowance, and recoveries, if any, are credited to the allowance. See “Note 10—Investments—Commercial Mortgage Loans.”
	Interest Income
	The Company records interest income in net investment income and continues to recognize interest income on delinquent commercial mortgage loans until the loans are more than 90 days delinquent. Interest income and accrued interest receivable are reversed when a loan is more than 90 days delinquent. For loans that are less than 90 days delinquent, management may reverse interest income and accrued interest receivable if there is a question on the collectability of the interest. Interest income on loans in the 90-day delinquent category is recognized in the period the cash is collected. The Company resumes the recognition of interest income when the loan becomes less than 90 days delinquent and management determines it is probable that the loan will remain performing.
	Real Estate
	Real estate is comprised of two components: real estate investments and real estate acquired in satisfaction of debt through foreclosure or acceptance of deeds in lieu of foreclosure on commercial mortgage loans (“Real Estate Owned”).
	Real estate investment properties are stated at cost less accumulated depreciation. Generally, the Company depreciates this real estate using the straight-line depreciation method with useful lives varying from 30 to 40 years. Accumulated depreciation for real estate totaled $13.4 million and $12.4 million at December 31, 2013 and 2012, respectively. The Company records impairments when it is determined that the decline in fair value of an investment below its carrying value is other than temporary. The impairment loss is charged to net capital losses, and the cost basis of the investment is permanently adjusted to reflect the impairment. There were no impairment losses recorded on real estate investment properties during 2013 or 2012.
	Real Estate Owned is initially recorded at the lower of cost or net realizable value, which includes an estimate for disposal costs. This amount may be adjusted in a subsequent period as additional information is received. Real Estate Owned is initially considered an investment held for sale and is expected to be sold within one year from acquisition. For any real estate expected to be sold, an impairment charge is recorded if the Company does not expect the investment to recover its carrying value prior to the expected date of sale. Once an impairment charge has been recorded, the Company continues to review the investment for further potential impairment. Impairments recorded on Real Estate Owned were $8.7 million, $3.0 million and $15.8 million for 2013, 2012 and 2011 respectively.
	All Other Investments
	Other invested assets include tax-advantaged investments, derivative financial instruments, policy loans and common stock. Valuation adjustments for these investments are recognized using the specific identification method.
	Tax-advantaged investments are accounted for under the equity method of accounting. These investments are structured as limited partnerships for the purpose of investing in the construction and rehabilitation of low-income housing and to provide favorable returns to investors. The Company has invested in tax-advantaged investments due to the higher returns associated with these investments relative to their perceived risk. The primary sources of investment return are tax credits and the tax benefits derived from passive losses on the investments, both of which may exhibit variability over the life of the investment. Tax credits received from these investments are reported in StanCorp's consolidated statements of income as either a reduction of state premium taxes, or a reduction of income tax. StanCorp's share of the operating losses of the limited partnerships decrease the basis in the investments and are reported as a component of net investment income. If the net present value of expected future cash flows of the tax-advantaged investments is less than the current book value of the investments, the Company evaluates whether a decline in value is other than temporary. If it is determined an OTTI exists, the investment is written down to the net present value of expected future cash flows and the OTTI is recognized as a capital loss.
	Derivative financial instruments are carried at fair value, and valuation adjustments are reported as a component of net investment income. See “Note 11—Derivative Financial Instruments.”
Policy loans are stated at their aggregate unpaid principal balances and are secured by policy cash values.
In November of 2013, the Company became a member of the Federal Home Loan Bank (“FHLB”) of Seattle and purchased the required common stock for membership. The common stock held by the Company relating to its membership in the FHLB of Seattle is carried at par value. The Company periodically evaluates FHLB stock for OTTI. The Company's determination of whether these investments are impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value.
Net investment income and capital gains and losses related to separate account assets and liabilities are included in the separate account assets and liabilities.
Cash and Cash Equivalents
Cash and cash equivalents include cash and investments purchased with original maturities of three months or less at the time of acquisition. The carrying amount of cash equivalents approximates the fair value of those instruments.
DAC, VOBA and Other Intangible Assets
DAC, VOBA and other acquisition related intangible assets are generally originated through the issuance of new business or the purchase of existing business, either by purchasing blocks of insurance policies from other insurers or by the outright purchase of other companies. The Company's intangible assets are subject to impairment tests on an annual basis or more frequently if circumstances indicate that carrying values may not be recoverable.
The Company defers certain acquisition costs that vary with and are directly related to the origination of new business and placing that business in force. Certain costs related to obtaining new business and acquiring business through reinsurance agreements have been deferred and will be amortized to accomplish matching against related future premiums or gross profits as appropriate. The Company normally defers certain acquisition-related commissions and incentive payments, certain costs of policy issuance and underwriting, and certain printing costs. Assumptions used in developing DAC and amortization amounts each period include the amount of business in force, expected future persistency, withdrawals, interest rates and profitability. These assumptions are modified to reflect actual experience when appropriate. Additional amortization of DAC is charged to current earnings to the extent it is determined that future premiums or gross profits are not adequate to cover the remaining amounts deferred. Changes in actual persistency are reflected in the calculated DAC balance. Costs that are not directly associated with the acquisition of new business are not deferred as DAC and are charged to expense as incurred. Generally, annual commissions are considered expenses and are not deferred.
DAC for group and individual disability insurance products and group life insurance products is amortized over the life of related policies in proportion to future premiums. The Company amortizes DAC for group disability and life insurance products over the initial premium rate guarantee period, which averages 2.5 years. DAC for individual disability insurance products is amortized in proportion to future premiums over the life of the contract, averaging 20 to 25 years with approximately 50% and 75% expected to be amortized by years 10 and 15, respectively.
The Company's individual deferred annuities and group annuity products are classified as investment contracts. DAC related to these products is amortized over the life of related policies in proportion to expected gross profits. For the Company's individual deferred annuities, DAC is generally amortized over 30 years with approximately 50% and 95% expected to be amortized by years 5 and 15, respectively. DAC for group annuity products is amortized over 10 years with approximately 80% expected to be amortized by year five.
VOBA primarily represents the discounted future profits of business assumed through reinsurance agreements. The Company has established VOBA for a block of individual disability business assumed from Minnesota Life Insurance Company (“Minnesota Life”) and a block of group disability and group life business assumed from Teachers Insurance and Annuity Association of America (“TIAA”). VOBA is generally amortized in proportion to future premiums for group and individual disability insurance products and group life products. However, the VOBA related to the TIAA transaction associated with an in force block of group long term disability claims for which no ongoing premium is received is amortized in proportion to expected gross profits. If actual premiums or future profitability are inconsistent with the Company's assumptions, the Company could be required to make adjustments to VOBA and related amortization. The VOBA associated with the TIAA transaction is amortized in proportion to expected gross profits with an amortization period of up to 20 years. For the VOBA associated with the Minnesota Life block of business assumed, the amortization period is up to 30 years and is amortized in proportion to future premiums.
Key assumptions, which will affect the determination of expected gross profits for determining DAC and VOBA balances, include:
Persistency.
Interest rates, which affect both investment income and interest credited.
Stock market performance.
Capital gains and losses.
Claim termination rates.
Amount of business in force.
These assumptions are modified to reflect actual experience when appropriate. Although a change in a single assumption may have an impact on the calculated amortization of DAC or VOBA for balances associated with investment contracts, it is the relationship of that change to the changes in other key assumptions that determines the ultimate impact on DAC or VOBA amortization. Because actual results and trends related to these assumptions vary from those assumed, we revise these assumptions annually to reflect our current best estimate of expected gross profits. As a result of this process, known as “unlocking,” the cumulative balances of DAC and VOBA are adjusted with an offsetting benefit or charge to income to reflect changes in the period of the revision. An unlocking event generally occurs as a result of actual experience or future expectations differing from previous estimates. As a result of unlocking, the amortization schedule for future periods is also adjusted.
Significant, unanticipated changes in key assumptions, which affect the determination of expected gross profits, may result in a large unlocking event that could have a material adverse effect on our financial position or results of operations.
The Company's other intangible assets are subject to amortization and consist of certain customer lists from Asset Management business acquired and an individual disability marketing agreement. Customer lists have a combined estimated weighted-average remaining life of approximately 6.8 years. The marketing agreement accompanied the Minnesota Life transaction and provides access to Minnesota Life agents, some of whom now market Standard's individual disability insurance products. The Minnesota Life marketing agreement will be fully amortized by the end of 2023.
Property and Equipment, Net
The following table sets forth the major classifications of the Company's property and equipment and accumulated depreciation:
			December 31,
(In millions)			2013		2012
Home office properties			$	136.9	$	135.3
Office furniture and equipment				47.9		47.7
Capitalized software				169.4		160.8
Leasehold improvements				13.9		13
	Property and equipment, gross			368.1		356.8
Less: accumulated depreciation				283.4		266.1
		Property and equipment, net	$	84.7	$	90.7
Property and equipment are stated at cost less accumulated depreciation. The Company depreciates property and equipment using the straight-line method over the estimated useful lives with a half-year convention. The estimated useful lives are generally 40 years for properties, range from three to ten years for equipment and range from three to five years for capitalized software. Leasehold improvements are depreciated over the lesser of the estimated useful life of the asset or the life of the lease. Depreciation expense for 2013, 2012 and 2011 was $19.9 million, $24.1 million and $28.0 million, respectively. The Company reviews property and equipment for impairment when circumstances or events indicate the carrying amount of the asset may not be recoverable and recognizes a charge to earnings if an asset is impaired.
Non-affiliated tenants leased 33.8%, 33.3% and 35.3% of the corporate headquarters in Portland, Oregon at December 31, 2013, 2012 and 2011, respectively. Income from the leases is included in net investment income.
Separate Account
Separate account assets and liabilities represent segregated funds held for the exclusive benefit of contract holders. The activities of the account primarily relate to contract holder-directed 401(k) agreements. Standard charges the separate account with asset management and plan administration fees associated with the contracts. Separate account assets are carried at fair value and separate account liabilities are carried at the amount of the related assets.
Reserves for Future Policy Benefits and Claims
Benefits and expenses are matched with recognized premiums to result in recognition of profits over the life of the contracts. The match is accomplished by recording a provision for future policy benefits and unpaid claims and claim adjustment expenses. For most of the Company's product lines, management establishes and carries as a liability actuarially determined reserves that are calculated to meet the Company's obligations for future policy benefits and claims. These reserves do not represent an exact calculation of the Company's future benefit liabilities but are instead estimates based on assumptions and considerations concerning a number of factors, which include:
The amount of premiums that the Company will receive in the future.
The rate of return on assets the Company purchases with premiums received.
Expected number and severity of claims.
Expenses.
Persistency, which is the measurement of the percentage of premiums remaining in force from year to year.
In particular, the Company's group and individual long term disability reserves are sensitive to assumptions and considerations regarding the following factors:
Claim incidence rates for incurred but not reported claim reserves.
Claim termination rates.
Discount rates used to value expected future claim payments.
Persistency rates.
The amount of monthly benefit paid to the insured, less reinsurance recoveries and other offsets.
Expense rates including inflation.
Historical delay in reporting of claims incurred.
Assumptions may vary by:
Age, gender and, for individual policies, occupation class of the claimant.
Year of issue for policy reserves or incurred date for claim reserves.
Time elapsed since disablement.
Contract provisions and limitations.
Other Policyholder Funds
Other policyholder funds are liabilities for investment-type contracts and are based on the policy account balances including accumulated interest. Other policyholder funds also include amounts related to advanced premiums of $186.1 million and $186.7 million at December 31, 2013 and 2012, respectively, and premiums on deposit and experience rated liabilities totaling $193.5 million and $216.1 million at December 31, 2013 and 2012, respectively.
Recognition of Premiums
Premiums from group life and group and individual disability contracts are recognized as revenue when due. Investment-type contract fee revenues consist of charges for policy administration and surrender charges assessed during the period. Charges related to services to be performed are deferred until earned. The amounts received in excess of premiums and fees are unearned and included in other policyholder funds in the consolidated balance sheets. Experience rated refunds are computed in accordance with the terms of the contracts with certain group policyholders and are accounted for as an adjustment to premiums.
Income Taxes
The Company files a U.S. consolidated income tax return that includes all subsidiaries. The Company's U.S. income tax is calculated using regular corporate income tax rates on a tax base determined by laws and regulations administered by the Internal Revenue Service (“IRS”). The Company also files corporate income tax returns in various states. The provision for income taxes includes amounts currently payable and deferred amounts that result from temporary differences between financial reporting and tax bases of assets and liabilities. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply when the temporary differences are expected to reverse.
GAAP requires management to use a more likely than not standard to evaluate whether, based on available evidence, each deferred tax asset will be realized. A valuation allowance is recorded to reduce a deferred tax asset to the amount expected to be realized.
Management is required to determine whether tax return positions are more likely than not to be sustained upon audit by taxing authorities. Tax benefits of uncertain tax positions, as determined and measured by this interpretation, cannot be recognized in the Company's financial statements.
The Company records income tax interest and penalties in the income tax provision according to the Company's accounting policy. See “Note 7—Income Taxes.”
Other Comprehensive Income
Other comprehensive income includes changes in unrealized capital gains and losses on fixed maturity securities, net of the related tax effects, and changes in unrealized prior service costs and credits and net gains and losses associated with the Company's employee benefit plans, net of the related tax effects.
Accounting Pronouncements
Accounting Standards Update (“ASU”) No. 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists
In July 2013, the Financial Accounting Standards Board issued ASU No. 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The main objective of ASU No. 2013-11 is to eliminate diversity in practice resulting from a lack of guidance on this topic. Under the guidance provided in this ASU, entities are required to present an unrecognized tax benefit in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward. If no such net operating loss carryforward is available at the reporting date, the unrecognized tax benefit should be presented in the financial statements as a liability.
ASU No. 2013-11 is effective for fiscal years beginning after December 15, 2013, and interim periods within those years. The Company does not currently have any unrecognized tax benefits. Therefore, the Company does not expect this ASU to have a material effect on its asset and liability disclosures in the financial statements.
ASU No. 2014-01, Accounting for Investments in Qualified Affordable Housing Projects
In January 2014, the Financial Accounting Standards Board issued ASU No. 2014-01, Accounting for Investments in Qualified Affordable Housing Projects. The main objective of ASU No. 2014-01 is to provide guidance on accounting for investments in affordable housing projects that qualify for low income housing tax credit. Under this guidance, entities could make a policy election to account for qualified affordable housing projects under the proportionate amortization method (“PAM”) of accounting. Under the PAM, the cost of low income housing tax credit investments is amortized in each period in proportion to the tax credits and benefits of tax losses received in that period and allows the benefits from tax losses on the asset, the losses that reduce the asset balance of the investment and the tax credits to be recorded in the income tax expense line.
ASU No. 2014-01 is effective for annual periods and interim reporting periods within those annual periods beginning after December 15, 2014. Early adoption is permitted. The Company currently invests in affordable housing projects that qualify for low income housing tax credit and is assessing the requirements for accounting for these investments under the PAM.

Net_Income_Per_Common_Share

Net Income Per Common Share	12 Months Ended
	Dec. 31, 2013
Net Income Per Common Share [Abstract]	'
Net Income Per Common Share	'
	2.       NET INCOME PER COMMON SHARE
	Net income per basic common share was calculated by dividing net income by the weighted-average number of common shares outstanding. Net income per diluted common share, as calculated using the treasury stock method, reflects the potential dilutive effects of stock award grants and exercises of dilutive outstanding stock options. The computation of diluted weighted-average earnings per share does not include stock options with an option exercise price greater than the average market price because they are antidilutive and inclusion would increase earnings per share.
	The following table sets forth the calculation of net income per basic and diluted weighted-average common shares outstanding:
			Years ended
			December 31,
	(Dollars in millions—except per share data)		2013			2012	2011
	Net income		$	228.5	$	138.5	$	136.7
	Basic weighted-average common shares outstanding			44,243,364		44,283,771		44,876,650
	Stock options			194,978		74,232		131,926
	Stock awards			89,063		1,888		7,494
	Diluted weighted-average common shares outstanding			44,527,405		44,359,891		45,016,070
	Net income per common share:
		Net income per basic common share	$	5.16	$	3.13	$	3.05
		Net income per diluted common share		5.13		3.12		3.04
	Antidilutive shares not included in net income per diluted common
		share calculation		292,750		2,220,045		1,974,242

ShareBased_Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2013
Share-Based Compensation [Abstract]	'
Share-Based Compensation	'
	3.       SHARE-BASED COMPENSATION
	The Company has two active share-based compensation plans: the 2002 Stock Incentive Plan (“2002 Plan”) and the 1999 Employee Share Purchase Plan (“ESPP”). The 2002 Plan authorizes the Board of Directors to grant incentive or non-statutory stock options and stock awards to eligible employees and certain specified parties. The Company's ESPP allows eligible employees to purchase StanCorp common stock at a discount.
	On May 13, 2013, shareholders approved an amendment to the 2002 Plan that increased the number of shares authorized for the 2002 Plan to 7,000,000 shares and increased the number of shares authorized to be allocated to stock awards to 1,700,000 shares.
	Of the 7,000,000 shares of common stock authorized for the 2002 Plan, 2,856,251 shares or options for shares remain available for grant at December 31, 2013. Of the 3,500,000 shares authorized for the ESPP, 1,425,002 shares remain available for issuance at December 31, 2013.
	The following table sets forth the total compensation cost and related income tax benefit under the Company's share-based compensation plans:
		Years ended
		December 31,
	(In millions)		2013			2012			2011
	Compensation cost	$		8.3		$	6.7		$	5.9
	Related income tax benefit			2.9			2.3			2.1
	2002 Plan
	The Company has provided two types of share-based compensation pursuant to the 2002 Plan: option grants and stock award grants.
	Option Grants
	Options are granted to officers and certain non-officer employees. Executive officers typically receive annual grants in amounts determined by the Organization & Compensation Committee of the Board of Directors. Non-executive officers typically receive annual grants as determined by management. Officers may also receive options when hired or promoted to an officer position. In addition, the Chief Executive Officer has authority to award a limited number of options at his discretion to non-executive officers and other employees. Options are granted with an exercise price equal to the closing market price of StanCorp common stock on the grant date. Options typically vest in four equal installments on the first four anniversaries of the vesting reference date. Option awards to certain officers vest if the officer's employment is terminated by the Company without cause or the officer terminates for good reason within 24 months after a change of control of the Company as defined in the Company's change of control agreement. Options generally expire 10 years from the grant date.
	The following table sets forth a summary of option activity and options outstanding and exercisable:
			Options			Weighted-Average Exercise Price			Weighted-Average Remaining Contractual Terms (Years)			Total Intrinsic Value(1)
	Outstanding, January 1, 2011			2,680,493		$	40.01			5.6		$	17,226,460
		Granted		272,785			44.18
		Exercised		-120,880			29.1
		Forfeited		-42,837			42.78
		Expired		-5,200			42.73
	Outstanding, December 31, 2011			2,784,361			40.84			5.1			5,947,355
		Granted		268,033			38.09
		Exercised		-294,226			25.67
		Forfeited		-16,300			39.56
		Expired		-37,700			45.06
	Outstanding, December 31, 2012			2,704,168			42.17			4.5			2,887,006
		Granted		211,367			44.27
		Exercised		-1,214,399			41.37
		Forfeited		-31,211			47.13
		Expired		-14,831			40.34
	Outstanding, December 31, 2013			1,655,094		$	43.02			5.6		$	38,455,709
	Options outstanding and exercisable:
		Vested or expected to be vested, December 31, 2013		1,636,282		$	43.02			5.5		$	38,004,456
		Fully vested and exercisable, December 31, 2013		1,278,866			43.24			4.7			29,430,648
	The intrinsic value of outstanding options can fluctuate significantly due to changes in the year end closing stock price from year to year.
	The fair value of each option award was estimated using the Black-Scholes option pricing model as of the grant date using the assumptions noted in the following table. The Black-Scholes option pricing model uses the expected term as an input with the calculated option value varying directly with the length of time until exercise. The Company bases its estimate of the expected term on an analysis of the historical exercise experience of similar options granted to similar employee or director groups. The expected term given below represents the weighted-average expected term of options granted. Expected stock price volatility is based on the volatility of StanCorp's common stock price over the prior period equal in duration to the expected term. The dividend rate is the rate expected to be paid over the expected term, generally estimated to be equal to the rate for the year prior to the grant. The risk-free rate is the interest rate on a U.S. Treasury bond of a maturity closest to the expected term of the option granted.
	The following table sets forth the weighted-average assumptions used to determine the fair value of option grants:
		Years ended
		December 31,
		2013			2012			2011
	Dividend yield		2.25	%		2.36	%		1.97	%
	Expected stock price volatility		45.86			47.3			46.24
	Risk-free interest rate		1.31			1.02			2.35
	Expected option lives		6.2 years			5.9 years			5.7 years
	The weighted-average grant date fair value of options granted was $16.15, $13.73 and $16.87 for 2013, 2012 and 2011, respectively.
	The total intrinsic value of the options exercised was $14.4 million, $3.2 million and $1.8 million for the same periods, respectively. The amount that the Company received from the exercise of stock options was $50.2 million, $7.6 million and $3.5 million for 2013, 2012 and 2011, respectively. The related tax benefit derived from the tax deduction received by the Company for the difference between the market price of StanCorp common stock and the exercise price when the options were exercised was $3.6 million, $1.1 million and $0.6 million for 2013, 2012 and 2011, respectively.
	The compensation cost of stock options is recognized over the vesting period, which is also the period over which the grantee must provide services to the Company. At December 31, 2013, the total cost related to unvested option awards that had not yet been recognized in the financial statements was $5.4 million. This cost will be recognized over a weighted-average period of 2.4 years.
	Stock Award Grants
	The Company grants three types of stock awards: restricted stock unit awards (“RSUs”), performance-based stock awards (“Performance Shares”) and non-employee director stock awards (“Director Stock Grants”). Under the 2002 Plan, the Company had 1,074,257 shares available for issuance as stock award grants at December 31, 2013.
	The following table sets forth a summary of the activity of RSU and Performance Shares outstanding:
			Restricted Stock Units						Performance Shares
			Activity			Weighted-Average Grant Date Fair Value			Activity		Weighted-Average Grant Date Fair Value
	Unvested balance, January 1, 2011			0		$	0		127,658		$	34.99
		Granted		0					116,978
		Vested		0					-6,504
		Forfeited		0					-47,164
	Unvested balance, December 31, 2011			0			0		190,968			44.05
		Granted		0					179,818
		Vested		0					-9,200
		Forfeited		0					-64,790
	Unvested balance, December 31, 2012			0			0		296,796			43.14
		Granted		59,823					129,172
	Vested		0					-13,964
	Forfeited		-3,057					-114,722
Unvested balance, December 31, 2013			56,766			38.56		297,282			40.34
RSUs
Beginning in the first quarter of 2013, the Company granted annual RSUs to officers and senior officers of the Company. RSUs typically cliff vest 3 years from the grant date. The actual number of shares issued is based on continued employment with a portion of shares withheld to cover required tax withholdings.
The fair value of the RSUs is determined based on the closing market price of StanCorp common stock on the grant date.
The compensation cost of RSUs is recognized over the vesting period, which is the period over which the grantee must provide services to the Company. At December 31, 2013, the total cost related to unvested RSUs that had not yet been recognized in the financial statements was $1.4 million. This cost will be recognized over a weighted-average remaining period of 2.0 years.
Performance Shares
The Company grants Performance shares to designated senior officers as long-term incentive compensation. The payout for these awards is based on the Company's financial performance over a three-year period. Performance Share grants represent the maximum number of shares of StanCorp common stock issuable to the designated senior officers if specified criteria are met. The actual number of shares issued at the end of the performance period is based on continued employment and satisfaction of Company financial performance conditions, with a portion of the shares withheld to cover required tax withholding.
Due to timing of when performance shares vested, the Company did not issue shares for 2013. The Company issued 9,899 and 4,906 shares of StanCorp common stock for 2012 and 2011, respectively, to redeem Performance Shares that vested following the 2011 and 2010 performance periods, net of Performance Shares withheld to cover the required taxes.
The fair value of the Performance Shares is determined based on the closing market price of StanCorp common stock on the grant date.
The compensation cost of Performance Shares is based on an estimate of the number of shares that will be earned and cost is recognized over the vesting period. The cost that the Company will ultimately recognize as a result of these stock awards is dependent on the Company's financial performance. Assuming that the maximum performance is achieved for each performance goal, $9.5 million in additional cost would be recognized through 2015. The target payout is 50% of the maximum Performance Shares for the 2014 and 2015 performance periods. Assuming that the target performance is achieved for each performance goal, $3.5 million in additional cost would be recognized through 2015. This cost would be recognized over a weighted-average period of 1.4 years.
Director Stock Grants
Each non-employee director receives annual stock grants with fair value equal to $100,000 based on the closing market price of StanCorp common stock on the day of the annual shareholder meeting. The stock grants generally vest after one year. Prior to May 7, 2012, the non-employee directors received compensation of $50,000 in stock options and $50,000 in stock grants.
The Company issued 20,099, 9,489 and 10,399 shares of StanCorp common stock for 2013, 2012 and 2011, respectively, related to the vesting of the annual Director stock grant for 2012, 2011 and 2010. The weighted-average fair value per share for the shares issued was $44.12, $36.40 and $43.00 for the same periods, respectively.
Employee Share Purchase Plan
The Company's ESPP allows eligible employees to purchase StanCorp common stock at a 5% discount of the lesser of the closing market price of StanCorp common stock on either the commencement date or the final date of each six-month offering period. Under the terms of the plan, each eligible employee may elect to have the lesser of up to 5% of the employee's gross total cash compensation or $5,000 per offering period withheld to purchase StanCorp common stock. No employee may purchase StanCorp common stock having a fair market value in excess of $25,000 in any calendar year.
Purchases prior to February 2, 2013 allowed for a purchase discount of 15% and contributions of up to 10% of the employee's gross total cash compensation.
The compensation cost for the ESPP is measured as the sum of the value of the discount and the value of the embedded six-month option. The value of the discount is equal to the available discount multiplied by of the fair market value of the common stock at the offering date. The value of the embedded option is calculated using the Black-Scholes option pricing model and the assumptions noted in the following table. Expected stock price volatility was based on the volatility of the price of StanCorp common stock during the six months preceding the offering period. The risk-free rate was based on the six-month U.S. Treasury yield curve in effect at the time of the grant.
The following table sets forth the assumptions used to determine the fair value of the ESPP embedded option:
	Years ended
	December 31,
	2013			2012			2011
Dividend yield		1.69-2.44	%		2.38-3.06	%		1.85-2.11	%
Expected stock price volatility		17.43-17.58			27.80-49.09			22.03-25.63
Risk-free interest rate		0.07-0.11			0.06-0.13			0.10-0.18
Expected option lives		0.5 years			0.5 years			0.5 years
The following table sets forth the fair value per share, compensation cost and related income tax benefit under the Company's ESPP:
	Years ended
	December 31,
(In millions except per share data)	2013			2012			2011
Weighted-average grant date fair value per share for ESPP offerings	$	4.16		$	9.02		$	9.46
Compensation cost		0.3			1.4			1.2
Related income tax benefit		0.1			0.5			0.4

Retirement_Benefits

Retirement Benefits	12 Months Ended
	Dec. 31, 2013
Retirement Benefits [Abstract]	'
Retirement Benefits	'
	4. RETIREMENT BENEFITS
	Pension Benefits
	The Company has two non-contributory defined benefit pension plans: the employee pension plan and the agent pension plan. The employee pension plan is generally limited to eligible employees of the Company whose date of employment began before 2003 and a participant is entitled to a normal retirement benefit at age 65. The agent pension plan is for former field employees and agents. The defined benefit pension plans provide benefits based on years of service and final average pay. The employee pension plan is sponsored by StanCorp and the agent pension plan is sponsored by Standard. Both plans are administered by Standard Retirement Services and are closed to new participants.
	The Company recognizes the funded status of the pension plans as an asset or liability on the balance sheet. The funded status is measured as the difference between the fair value of the plan assets and the projected benefit obligation as of the year-end balance sheet date.
	The following table sets forth a reconciliation of the changes in the pension plans' projected benefit obligations, fair value of plan assets and the funded status:
								Years ended
								December 31,
	(In millions)							2013			2012			2011
	Change in projected benefit obligation:
			Projected benefit obligation at beginning of the year					$	-418.5		$	-371.6		$	-323.7
			Service cost						-10.2			-9.7			-9.2
			Interest cost						-16.7			-16.5			-17.5
			Actuarial gain (loss)						26			-29.7			-29
			Benefits paid						11			9			7.8
				Projected benefit obligation at end of the year					-408.4			-418.5			-371.6
	Change in fair value of plan assets:
			Fair value of plan assets at beginning of the year						386			349.7			292.6
			Actual return on plan assets						65.4			35.4			7
			Employer contributions						---			10			58
			Benefits paid and estimated expenses						-11			-9.1			-7.9
				Fair value of plan assets at end of the year					440.4			386			349.7
						Funded status at end of the year		$	32		$	-32.5		$	-21.9
	The following table sets forth the projected and accumulated benefit obligations and the fair value of the plan assets for the pension plans:
		December 31,
	(In millions)	2013			2012			2011
	Projected benefit obligation	$	408.4		$	418.5		$	371.6
	Accumulated benefit obligation		374.2			386.5			337.5
	Fair value of plan assets		440.4			386			349.7
	The Company recognizes as a component of accumulated other comprehensive (income) loss, net of tax, the actuarial gains or losses, prior service costs or credits, and transition assets that have not yet been recognized as components of net periodic benefit cost.
	The following table sets forth the amounts recognized in accumulated other comprehensive (income) loss:
			Years ended
			December 31,
	(In millions)		2013			2012			2011
	Net loss		$	31.4		$	78.3		$	70.1
	Prior service cost			2.3			2.7			3.1
		Total recognized in accumulated other comprehensive (income) loss	$	33.7		$	81		$	73.2
	The estimated net loss and prior service cost for the pension plans that will be amortized from accumulated other comprehensive (income) loss into net periodic benefit cost in 2014 are $0.2 million and $0.4 million net of tax, respectively.
	The following table sets forth the components of net periodic benefit cost, other changes in plan assets and benefit obligations recognized in other comprehensive (income) loss, and assumptions used in the measurement of the net periodic benefit cost and the benefit obligations:
								Years ended
								December 31,
	(Dollars in millions)							2013			2012			2011
	Components of net periodic benefit cost:
			Service cost					$	10.3		$	9.8		$	9.3
			Interest cost						16.7			16.5			17.5
			Expected return on plan assets						-29.3			-26.5			-22.1
			Amortization of prior service cost						0.6			0.6			0.6
			Amortization of net actuarial loss						9.9			8.3			4
					Net periodic benefit cost				8.2			8.7			9.3
	Other changes in plan assets and benefit obligation recognized
		in other comprehensive (income) loss:
			Net (gain) loss						-62.2			20.9			44.1
			Amortization of prior service cost						-0.6			-0.6			-0.6
			Amortization of net actuarial loss						-9.9			-8.3			-4
					Total recognized in other comprehensive (income) loss				-72.7			12			39.5
						Total recognized in net periodic benefit cost and other
							comprehensive (income) loss	$	-64.5		$	20.7		$	48.8
	Weighted-average assumptions:
		Assumptions used for net periodic benefit cost:
			Discount rate						4	%		4.5	%		5.5	%
			Expected return on plan assets						7.7			7.69			7.68
			Rate of compensation increase						3			3.25			4.5
		Assumptions used to determine benefit obligations:
			Discount rate						4.75	%		4	%		4.5	%
		Rate of compensation increase						3.5			3			3.25
The long-run rate of return for the employee pension plan portfolio is derived by calculating the average return for the portfolio monthly, from 1971 to the present, using the average mutual fund manager returns in each asset category, weighted by the target allocation to each category.
The company did not make any contributions to the employee pension plan in 2013. The Company made contributions of $10.0 million and $58.0 million to the employee pension plan in 2012 and 2011, respectively. The Company is not obligated to make any contributions to its pension plans for 2014. In addition, no plan assets are expected to be returned to the Company in 2014.
The following table sets forth the expected benefit payments for the Company's pension plans:
(In millions)		Amount
2014		$	11.8
2015			13
2016			14.3
2017			15.6
2018			17
2019-2023			105.4
The investment goal of the employee pension plan is to produce long-run portfolio returns that are consistent with reasonable contribution rates and a well-funded plan. To manage the overall risk of the portfolio, the portfolio is reviewed quarterly and rebalanced as necessary to keep the allocation of debt and equity securities within target allocation tolerance levels. The equity securities include pooled separate account funds comprised of large cap growth, large cap blend, large cap value, mid cap blend and foreign mutual funds and are diversified across investment strategies. The employee pension plan held no StanCorp equity securities as plan assets at December 31, 2013 and 2012. The plan invests in a stable asset fund comprised of debt securities included in the general account represented by a Deposit Administration Contract with Standard. Standard maintains the contributions in an unallocated fund, whose assets are invested with other assets in the general account of Standard. The account is credited with earnings on the underlying investments and charged for plan withdrawals and administrative expenses charged by Standard Retirement Services. The stable asset fund contract may subject the plan to concentrations of risk as its contract value is dependent on the ability of Standard to honor its contractual commitments. There are no reserves against the contract value for credit risk of Standard or otherwise.
The investment goal of the agent pension plan is to invest in stable value assets in order to maintain its funded status.
The following table sets forth the Company's target and actual weighted-average asset allocations for the pension plans:
		December 31,
		2013			2013			2012
		Target			Actual			Actual
Asset Category:
	Equity securities		50	%		49	%		48.9	%
	Debt securities		50			51			51.1
	Total		100	%		100	%		100	%
Pension plan assets are recorded at fair value and are disclosed below using a three-level hierarchy. See “Note 9—Fair Value” for additional fair value information. The fair values of pooled separate accounts are valued daily based upon quoted market prices in an active market and are classified as Level 1 assets. Pooled separate accounts are recorded at fair value on a recurring basis. The fair value of the stable asset fund is included in the financial statements at the Deposit Administration Contract value and was classified as a Level 2 asset. The contract value approximates fair value, as the contract crediting rate resets annually, and the contracts are fully benefit-responsive. Contract value represents contributions made under the contracts, plus earnings, less withdrawals and administrative expenses.
The following tables set forth the estimated fair values of assets and liabilities measured and recorded at fair value on a recurring basis:
							31-Dec-13
(In millions)							Total			Level 1			Level 2			Level 3
Assets:
	Equity securities:
		Pooled separate account funds:
			Large cap growth				$	43		$	43		$	0		$	0
			Large cap blend					64.7			64.7			0			0
			Large cap value					21.7			21.7			0			0
			Mid cap blend					64.8			64.8			0			0
			Foreign					21.7			21.7			0			0
				Total pooled separate account funds				215.9			215.9			0			0
	Debt securities:
			Stable asset fund					224.5			0			224.5			0
				Total			$	440.4		$	215.9		$	224.5		$	0
							31-Dec-12
(In millions)							Total			Level 1			Level 2			Level 3
Assets:
	Equity securities:
		Pooled separate account funds:
			Large cap growth				$	39.3		$	39.3		$	0		$	0
			Large cap blend					57.5			57.5			0			0
			Large cap value					19.3			19.3			0			0
			Mid cap blend					54.7			54.7			0			0
			Foreign					18			18			0			0
				Total pooled separate account funds				188.8			188.8			0			0
	Debt securities:
			Stable asset fund					197.2			0			197.2			0
				Total			$	386		$	188.8		$	197.2		$	0
There were no transfers into or out of Level 3 for 2013 and 2012.
As a result of inputs used during the current period to estimate the fair value of stable asset fund, Plan management has categorized the stable asset fund as having Level 2 inputs at December 31, 2013. The valuation methods may produce fair value calculations that may not be indicative of net realizable values or reflective of future fair values. See “Note 9—Fair Value” for further disclosure on valuation methods. Furthermore, although the Plan believes its valuation methods are appropriate and consistent with other market participants, the use of different methodologies or assumptions to determine the fair value of certain financial instruments could result in a different fair value measurement at the reporting date.
Deferred Compensation Plans
Eligible employees are covered by a qualified deferred compensation plan sponsored by Standard under which a portion of the employee contribution is matched. Employees not eligible for the employee pension plan are eligible for an additional non-elective employer contribution. Contributions to the plan for 2013, 2012 and 2011 were $9.9 million, $9.9 million and $10.3 million, respectively.
Eligible executive officers, directors, agents and group producers may participate in one of several non-qualified deferred compensation plans under which a portion of the deferred compensation for participating executive officers, agents and group producers is matched. The liability for the plans was $11.6 million and $10.5 million at December 31, 2013 and 2012, respectively.
Postretirement Benefits Other Than Pensions
Standard sponsors and administers a postretirement benefit plan that includes medical, prescription drug benefits and group term life insurance. Eligible retirees are required to contribute specified amounts for medical and prescription drug benefits that are determined periodically and are based on retirees' length of service and age at retirement. As of January 1, 2006, participation in the postretirement benefit plan was closed to new participants. At the end of 2012, the postretirement benefit plan was amended to reduce future benefits to plan participants that were either not eligible to or chose not to retire on or before July 1, 2013. The 2012 amendment did not affect future benefits for employees who were retired as of July 1, 2013. In addition, as of December 31, 2011, the group term life insurance benefit was curtailed for plan participants who were not retired at December 31, 2011.
The Company recognizes the funded status of the postretirement benefit plan as an asset or liability on the balance sheet. The funded status is measured as the difference between the fair value of the plan assets and the accumulated benefit obligation.
The following table sets forth a reconciliation of the changes in the postretirement benefit plan's accumulated postretirement benefit obligation, fair value of plan assets and the funded status:
							Years ended
							December 31,
(In millions)							2013			2012			2011
Change in accumulated postretirement benefit obligation:
		Accumulated postretirement benefit obligation at beginning of the year					$	-23.9		$	-41		$	-40.5
		Service cost						---			-1			-1.5
		Interest cost						-1.1			-1.8			-2.1
		Plan amendments						0.8			25.2			8
		Actuarial gain (loss)						5.2			-5.9			-5.4
		Benefits paid						1.4			0.6			0.5
			Accumulated postretirement benefit obligation at end of the year					-17.6			-23.9			-41
Change in fair value of postretirement plan assets:
		Fair value of plan assets at beginning of the year						21.6			20.7			18.2
		Actual return on plan assets						-1.6			1.2			2.7
		Employer contributions						0.7			0.3			0.3
		Benefits paid and estimated expenses						-1.4			-0.6			-0.5
			Fair value of plan assets at end of the year					19.3			21.6			20.7
					Funded status at end of the year		$	1.7		$	-2.3		$	-20.3
The gains and losses, and prior service costs or credits excluded from the projected benefit obligation are recognized as a component of accumulated other comprehensive (income) loss, net of tax.
The following table sets forth the amounts recognized in accumulated other comprehensive (income) loss:
		Years ended
		December 31,
(In millions)		2013			2012			2011
Net (gain) loss		$	-1		$	5.1		$	2.2
Prior service credit			---			-17.1			-1
	Total recognized in accumulated other comprehensive (income) loss	$	-1		$	-12		$	1.2
In 2014, there is no estimated prior service credit or net (gain) loss for the postretirement benefit plan that will be amortized from accumulated other comprehensive (income) loss into net periodic benefit cost. The projected discounted cash flow obligation for the postretirement benefit plan was $17.6 million and $24.0 million at December 31, 2013 and 2012, respectively.
The following table sets forth the assumed health care cost trend rates for next year:
	Years ended
	December 31,
	2013			2012
Medical		7.1	%		7.3	%
Prescriptions		7.5			7.8
HMO (Blended)		6			6.4
Rate to which the cost trend is assumed to decline (the ultimate trend rate)*		4.5			4.5
*       Year that the rate reaches the ultimate trend is 2027.
Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plans. A one-percentage-point change in assumed health care cost trend rates would have the following effects:
					1% Point			1% Point
(In millions)					Increase			Decrease
Effect on total of service and interest cost					$	0.1		$	-0.1
Effect on postretirement benefit obligation						1.5			-1.3
The following table sets forth the components of net periodic benefit cost, other changes in plan assets and benefit obligations recognized in other comprehensive (income) loss, and assumptions used in the measurement of the postretirement net periodic benefit cost and the postretirement benefit obligations:
							Years ended
							December 31,
(Dollars in millions)							2013			2012			2011
Components of net periodic benefit cost:
		Service cost					$	0		$	1		$	1.5
		Interest cost						1			1.8			2.1
		Expected return on plan assets						-0.8			-0.8			-0.8
		Amortization of prior service cost						-26.3			-0.4			-0.3
		Amortization of net actuarial loss						5.7			0			0.1
		Curtailment loss						0			0			0.7
				Net periodic benefit cost				-20.4			1.6			3.3
Other changes in plan assets and benefit obligation recognized
	in other comprehensive (income) loss:
		Net loss						-3.3			5.5			6.1
		Prior service credit						0			-25.2			0
		Amortization of prior service credit						26.3			0.4			0.2
		Amortization of net actuarial loss						-5.8			0			-0.1
				Total recognized in other comprehensive loss (income)				17.2			-19.3			6.2
					Total recognized in net periodic benefit cost and other
						comprehensive (income) loss	$	-3.2		$	-17.7		$	9.5
Weighted-average assumptions:
	Assumptions used for net periodic benefit cost:
		Discount rate						4	%		4.5	%		5.5	%
		Expected return on plan assets						4.2			4.2			4.5
		Rate of compensation increase graded by age						n/a*			n/a*			5
	Assumptions used to determine benefit obligations:
		Discount rate						4.8	%		4	%		4.5	%
		Rate of compensation increase graded by age						n/a*			n/a*			n/a*
* Assumption for rate of compensation increase was not applicable in determining benefit obligations for 2013, 2012 and 2011or net periodic benefit cost in 2013 and 2012 due to curtailment of group term life insurance benefit as of December 31, 2011.
For the postretirement benefit plan, the expected long-term rate of return on assets was developed by considering the historical returns and the future expectations for returns, as well as the target asset allocation.
The Company contributed $0.4 million, $0.3 million and $0.3 million to fund the postretirement benefit plan in 2013, 2012 and 2011, respectively. The Company expects to make contributions of $0.6 million to its postretirement benefit plan in 2014. No plan assets are expected to be returned to the Company in 2014.
The following table sets forth the expected benefit payments for the Company's postretirement benefit plan:
(In millions)		Amount
2014		$	1.3
2015			1.3
2016			1.3
2017			1.2
2018			1.2
2019-2023			5.6
The investment goal of the postretirement plan is to produce a steady return on plan assets to maintain its funded status. To achieve this goal, the Company's postretirement benefit plan assets are comprised primarily of municipal bonds and cash and cash equivalents.
The following table sets forth the Company's target and actual weighted-average asset allocations for the postretirement medical plan:
			Years ended
			December 31,
			2013			2013			2012
			Target			Actual			Actual
Asset category:
	Debt securities			95	%		96.2	%		92.6	%
	Cash and cash equivalents			5			3.8			7.4
		Total		100	%		100	%		100	%
Postretirement benefit plan assets are recorded at fair value and are disclosed below using a three-level hierarchy. See “Note 9—Fair Value” for additional fair value information. As there was not an active market for the Company's municipal bond holdings at December 31, 2013, the municipal bonds were valued using Level 2 measurements.
The following tables set forth the estimated fair values of assets and liabilities measured and recorded at fair value on a recurring basis:
							31-Dec-13
(In millions)							Total			Level 1			Level 2			Level 3
Assets:
	Debt securities:
		Municipal bonds					$	16.8		$	0		$	16.8		$	0
		Corporate bonds						1.8			0			1.8			0
	Cash and cash equivalents							0.7			0.7			0			0
			Total				$	19.3		$	0.7		$	18.6		$	0
							31-Dec-12
(In millions)								Total			Level 1		Level 2			Level 3
Assets:
	Debt securities:
		Municipal bonds					$	19		$	0		$	19		$	0
		Corporate bond						1			0			1			0
	Cash and cash equivalents							1.6			1.6			0			0
			Total				$	21.6		$	1.6		$	20		$	0
Non-Qualified Supplemental Retirement Plan
Eligible executive officers are covered by a non-qualified supplemental retirement plan (“non-qualified plan”). Under the non-qualified plan, a participant is entitled to a normal retirement benefit once the participant reaches age 65. A participant can also receive a normal, unreduced retirement benefit once the sum of his or her age plus years of service is at least 90. The Company recognizes the unfunded status of the non-qualified plan in other liabilities on the balance sheet. The unfunded status was $31.1 million and $27.5 million at December 31, 2013 and 2012, respectively. Expenses were $3.1 million, $1.9 million and $2.5 million for 2013, 2012 and 2011, respectively. The net loss and prior service cost, net of tax, excluded from the net periodic benefit cost and reported as a component of accumulated other comprehensive income were $5.7 million, $4.7 million and $5.7 million at December 31, 2013, 2012 and 2011, respectively.

Segments

Segments	12 Months Ended
	Dec. 31, 2013
Segments [Abstract]	'
Segments	'
	5. SEGMENTS
	The Company collectively views and operates its businesses as Insurance Services and Asset Management, which both deliver distinct value to customers and shareholders. Insurance Services contains two reportable product segments, Employee Benefits and Individual Disability. Due to the growth in the Individual Disability business in relation to total Insurance Services over the last several years, Individual Disability has become a separate reportable product segment within Insurance Services in 2013. Asset Management provides investment and asset management products and services and is reported as a separate segment. Holding company and corporate activities are reported in the Other category. Resources are allocated and performance is evaluated at the segment level. Insurance Services offers group and individual disability insurance, group life and AD&D insurance, group dental and group vision insurance, and absence management services. Asset Management offers full-service 401(k) plans, 403(b) plans, 457 plans, defined benefit plans, money purchase pension plans, profit sharing plans and non-qualified deferred compensation products and services. Asset Management also offers investment advisory and management services, financial planning services, origination and servicing of fixed-rate commercial mortgage loans, individual fixed-rate annuity products, group annuity contracts and retirement plan trust products. The Other category includes return on capital not allocated to the product segments, holding company expenses, operations of certain unallocated subsidiaries, interest on debt, unallocated expenses, net capital gains and losses related to the impairment or the disposition of the Company's invested assets and adjustments made in consolidation. The accounting policies of the segments are the same as those described in the summary of significant accounting policies. See “Note 1—Summary of Significant Accounting Policies.”
	Intersegment revenues are comprised of administrative fee revenues charged by the Asset Management segment to manage the fixed maturity securities and commercial mortgage loan portfolios for the Company's insurance subsidiaries. Intersegment fees are determined based on the level of assets in the insurance subsidiaries' fixed maturity securities and commercial mortgage loan portfolios.
	The following table sets forth intersegment revenues:
		Years ended
		December 31,
	(In millions)	2013			2012			2011
	Intersegment administrative fee revenues	$	18.6		$	17.9		$	16.7
	The following table sets forth premiums, administrative fee revenues and net investment income by major product line or category within each of the Company's segments:
							Years ended
							December 31,
	(In millions)						2013			2012			2011
	Premiums:
		Insurance Services:
			Group life and AD&D				$	849.7		$	883.7		$	892.6
			Group long term disability					783			801.4			803.3
			Group short term disability					229			212.6			208
			Group other					78.3			78.9			81.6
			Experience rated refunds					-13.1			4			-12.5
				Total Employee Benefits				1,926.90			1,980.60			1,973.00
				Individual Disability				190.5			176.6			172.3
					Total Insurance Services premiums			2,117.40			2,157.20			2,145.30
		Asset Management:
				Retirement plans				2.2			1.9			2
				Individual annuities				4.7			4.8			6
					Total Asset Management premiums			6.9			6.7			8
						Total premiums	$	2,124.30		$	2,163.90		$	2,153.30
	Administrative fees:
		Insurance Services:
				Employee Benefits			$	15.1		$	13.7		$	12
				Individual Disability				0.2			0.2			0.3
					Total Insurance Services administrative fees			15.3			13.9			12.3
		Asset Management:
				Retirement plans				93.3			88			90
				Other financial services businesses				31.6			30.8			29.9
					Total Asset Management administrative fees			124.9			118.8			119.9
		Other						-18.6			-18			-16.7
						Total administrative fees	$	121.6		$	114.7		$	115.5
	Net investment income:
		Insurance Services:
				Employee Benefits			$	267.8		$	286		$	288.6
				Individual Disability				52.8			53.7			52.7
					Total Insurance Services net investment income			320.6			339.7			341.3
		Asset Management:
				Retirement plans				103.2			94.9			90.4
				Individual annuities				177.2			170.6			161
				Other financial services businesses				12.8			13.1			11.3
					Total Asset Management net investment income			293.2			278.6			262.7
		Other						16.1			10.2			8.8
						Total net investment income	$	629.9		$	628.5		$	612.8
	The following tables set forth select segment information:
					Year ended
					31-Dec-13
											Total
					Employee			Individual			Insurance			Asset
	(In millions)				Benefits			Disability			Services			Management		Other		Total
	Revenues:
		Premiums			$	1,926.90		$	190.5		$	2,117.40		$	6.9	$	0	$	2,124.30
		Administrative fees				15.1			0.2			15.3			124.9		-18.6		121.6
		Net investment income				267.8			52.8			320.6			293.2		16.1		629.9
		Net capital losses				0			0			0			0		-15.7		-15.7
				Total revenues		2,209.80			243.5			2,453.30			425		-18.2		2,860.10
	Benefits and expenses:
	Benefits to policyholders				1,515.90			121.8			1,637.70			17.7		0		1,655.40
	Interest credited				4.3			0			4.3			172.1		0		176.4
	Operating expenses				313.3			26.7			340			116.5		-13.9		442.6
	Commissions and bonuses				126.7			47.5			174.2			33.7		0		207.9
	Premium taxes				31.3			3.9			35.2			0.1		0		35.3
	Interest expense				0			0			0			0		34.4		34.4
	Net decrease (increase) in DAC,
		VOBA and other intangible assets			1.9			-12.4			-10.5			5.6		0		-4.9
			Total benefits and expenses		1,993.40			187.5			2,180.90			345.7		20.5		2,547.10
Income (loss) before income taxes				$	216.4		$	56		$	272.4		$	79.3	$	-38.7	$	313
Total assets				$	5,744.70		$	2,343.40		$	8,088.10		$	12,777.10	$	528.1	$	21,393.30
				Year ended
				31-Dec-12
										Total
				Employee			Individual			Insurance			Asset
(In millions)				Benefits			Disability			Services			Management		Other		Total
Revenues:
	Premiums			$	1,980.60		$	176.6		$	2,157.20		$	6.7	$	0	$	2,163.90
	Administrative fees				13.7			0.2			13.9			118.8		-18		114.7
	Net investment income				286			53.7			339.7			278.6		10.2		628.5
	Net capital losses				0			0			0			0		-8.7		-8.7
			Total revenues		2,280.30			230.5			2,510.80			404.1		-16.5		2,898.40
Benefits and expenses:
	Benefits to policyholders				1,657.10			116.2			1,773.30			19.7		0		1,793.00
	Interest credited				4.2			0			4.2			167.1		0		171.3
	Operating expenses				323.6			25.5			349.1			117.4		4		470.5
	Commissions and bonuses				125.1			47.6			172.7			31		0		203.7
	Premium taxes				33.6			3.9			37.5			0		0		37.5
	Interest expense				0			0			0			0		39.9		39.9
	Net decrease (increase) in DAC,
		VOBA and other intangible assets			6.9			-12.7			-5.8			4.9		0		-0.9
			Total benefits and expenses		2,150.50			180.5			2,331.00			340.1		43.9		2,715.00
Income (loss) before income taxes				$	129.8		$	50		$	179.8		$	64	$	-60.4	$	183.4
Total assets				$	5,991.40		$	2,259.40		$	8,250.80		$	11,046.00	$	494.5	$	19,791.30
				Year ended
				31-Dec-11
										Total
				Employee			Individual			Insurance			Asset
(In millions)				Benefits			Disability			Services			Management		Other		Total
Revenues:
	Premiums			$	1,973.00		$	172.3		$	2,145.30		$	8	$	0	$	2,153.30
	Administrative fees				12			0.3			12.3			119.9		-16.7		115.5
	Net investment income				288.6			52.7			341.3			262.7		8.8		612.8
	Net capital losses				0			0			0			0		-6.9		-6.9
			Total revenues		2,273.60			225.3			2,498.90			390.6		-14.8		2,874.70
Benefits and expenses:
	Benefits to policyholders				1,635.00			115.9			1,750.90			20.3		0		1,771.20
	Interest credited				4.6			0			4.6			156.4		0		161
	Operating expenses				312.3			26.4			338.7			115.2		17.3		471.2
	Commissions and bonuses				137.1			48			185.1			33.6		0		218.7
	Premium taxes				33			3.6			36.6			0.1		0		36.7
	Interest expense				0			0			0			0		38.9		38.9
	Net (increase) decrease in DAC,
		VOBA and other intangible assets			-4.3			-13.9			-18.2			3.7		0		-14.5
			Total benefits and expenses		2,117.70			180			2,297.70			329.3		56.2		2,683.20
Income (loss) before income taxes				$	155.9		$	45.3		$	201.2		$	61.3	$	-71	$	191.5
Total assets				$	6,002.90		$	2,201.90		$	8,204.80		$	9,922.90	$	275.5	$	18,403.20

Parent_Holding_Company_Condens

Parent Holding Company Condensed Financial Information	12 Months Ended
	Dec. 31, 2013
Parent Holding Company Condensed Financial Information [Abstract]	'
Parent Holding Company Condensed Financial Information	'
	6.       PARENT HOLDING COMPANY CONDENSED FINANCIAL INFORMATION
	Set forth below are the unconsolidated condensed financial statements of StanCorp. The significant accounting policies used in preparing StanCorp's financial statements are substantially the same as those used in the preparation of the consolidated financial statements of the Company except that StanCorp's subsidiaries are carried under the equity method.
	The following table sets forth StanCorp's condensed statements of income and comprehensive income:
					Years ended
					December 31,
	(In millions)					2013			2012			2011
	Revenues:
		Net investment income				$	13.2		$	5		$	0
		Net capital gains (losses)					0.2			0.1			-0.3
				Total revenues			13.4			5.1			-0.3
	Expenses:
		Interest expense					34.2			39.7			38.8
		Operating expenses					0.9			4.5			11.2
				Total expenses			35.1			44.2			50
	Loss before income taxes and equity in net income of subsidiaries						-21.7			-39.1			-50.3
	Income tax benefit						-7.7			-14.2			-10.8
	Equity in net income of subsidiaries						242.5			163.4			176.2
	Net income						228.5			138.5			136.7
	Other comprehensive income (loss), net of tax:
		Other comprehensive income from parent					47			1.7			0
		Other comprehensive (loss) income from subsidiaries					-221.6			72.5			74.2
			Total other comprehensive (loss) income, net of tax				-174.6			74.2			74.2
	Comprehensive income					$	53.9		$	212.7		$	210.9
	The following table sets forth StanCorp's condensed balance sheets:
					December 31,
	(In millions)				2013			2012
	A S S E T S
	Cash and cash equivalents				$	125.2		$	39.7
	Investment in subsidiaries					2,252.90			2,352.50
	Receivable from subsidiaries					1.5			1.2
	Surplus note receivable from subsidiary					250			250
	Other assets					80.3			114.3
				Total assets	$	2,709.90		$	2,757.70
	L I A B I L I T I E S A N D S H A R E H O L D E R S’ E Q U I T Y
	Liabilities:
		Long-term debt			$	550		$	550
		Other liabilities				7.1			38.7
			Total liabilities			557.1			588.7
	Shareholders’ equity:
			Total shareholders' equity			2,152.80			2,169.00
				Total liabilities and shareholders’ equity	$	2,709.90		$	2,757.70
	The following table sets forth StanCorp's condensed statements of cash flows:
					Years ended
					December 31,
	(In millions)				2013				2012		2011
	Operating:
		Net income			$	228.5		$	138.5		$	136.7
		Adjustments to reconcile net income to net cash provided by operating activities:
			Equity in net income of subsidiaries			-242.5			-163.4			-176.2
			Dividends received from consolidated subsidiaries			147			328.7			94.3
			Changes in operating assets and liabilities			23.7			-2.5			-24.5
				Net cash provided by operating activities		156.7			301.3			30.3
	Investing:
		Capital contributions to subsidiaries				-0.7			-14.5			-9
		Return of capital from subsidiaries				7.8			7.3			76.1
		Surplus note receivable from subsidiary				0			-250			0
		Receivables from subsidiaries, net				-0.3			3.4			13.3
		Investment securities and other				0.2			1.4			0.3
				Net cash provided by (used in) investing activities		7			-252.4			80.7
	Financing:
		Issuance and repurchase of common stock, net				-29.7			0.9			-81.3
		Repayment of debt				0			-250			0
		Issuance of debt, net of issuance costs				0			246.7			0
	Dividends paid on common stock				-48.5			-41.3			-39.3
			Net cash used in financing activities		-78.2			-43.7			-120.6
Increase (decrease) in cash and cash equivalents					85.5			5.2			-9.6
Cash and cash equivalents, beginning of year					39.7			34.5			44.1
Cash and cash equivalents, end of year				$	125.2		$	39.7		$	34.5

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2013
Income Taxes Disclosure [Abstract]	'
Income Taxes	'
	7. INCOME TAXES
	The following table sets forth the provision for income taxes:
			Years ended
			December 31,
	(In millions)		2013			2012			2011
	Current		$	71.1		$	38.5		$	40.5
	Deferred			13.4			6.4			14.3
		Total income tax provision	$	84.5		$	44.9		$	54.8
	The following table sets forth the reconciliation between taxes calculated as if the federal corporate tax rate of 35% was applied to income before income taxes and the recorded income tax provision:
				Years ended
				December 31,
	(In millions)			2013			2012			2011
	Tax at federal corporate rate of 35%			$	109.6		$	64.2		$	67
	(Decrease) increase in rate resulting from:
		Tax exempt interest			-			-0.1			-0.1
		Dividends received deduction			-3.6			-3.6			-3.1
		State income taxes, net of federal benefit			1.3			0.2			-0.1
		Federal tax credits			-24.9			-17.4			-8.6
		Other			2.1			1.6			-0.3
			Total income tax provision	$	84.5		$	44.9		$	54.8
	The following table sets forth the tax effect of temporary differences that gave rise to significant portions of the net deferred tax liability:
					December 31,
	(In millions)				2013			2012			2011
	Policyholder liabilities				$	1.2		$	1.8		$	9.3
	Compensation and benefit plans					12.6			44			42.4
	Loss carryforwards					49.7			51.7			56.2
	Investments					45.6			35.8			41.4
	Other					3.5			2.2			1.9
		Total deferred tax assets				112.6			135.5			151.2
	Less: valuation allowances					-9.5			-3.1			-4.2
			Net deferred tax assets			103.1			132.4			147
	Net unrealized capital gains					95.7			210			173.9
	Capitalized software					6.8			8.3			10.2
	Deferred policy acquisition costs					63.5			59.7			61.6
	Intangible assets					0.9			2			3.2
	Other					0.9			0.5			1.1
		Total deferred tax liabilities				167.8			280.5			250
			Net deferred tax liability		$	-64.7		$	-148.1		$	-103
	The Company is carrying forward net operating losses (“NOL”) of $58 million that originated in StanCorp and certain subsidiaries. The losses will be used in future years to offset taxable income from those entities to the degree allowed by the Internal Revenue Code. If unutilized, these losses would expire between the years 2023 to 2032. In addition, the Company is carrying forward a $53 million federal NOL from a business acquisition. This carryforward is subject to limitations under IRS Section 382, which potentially reduces the annual amount that may be utilized. This NOL carryforward will expire between 2019 and 2024.
	Realization of the Company's NOL carryforwards is dependent upon generating sufficient taxable income of the appropriate character before expiration of the losses. Although realization is not assured, management believes it is more likely than not that all of the deferred tax asset relating to the federal loss carryforwards will be realized. The amount of the deferred tax asset considered realizable could be reduced in the future if estimates of expected taxable income during the carryforward period are reduced.
	The Company is carrying forward a deferred tax asset of $11 million related to losses attributable to various states and municipalities. In some instances, state and local loss carryforwards are subject to a shorter expiration period than the 20-year federal period. Further, some losses originated in a subsidiary which has reduced its operations in the state where the loss was incurred. The Company believes that the benefit from certain state and local NOL carryforwards will not be realized. As such, the Company has provided a valuation allowance of $9.5 million at December 31, 2013 on the deferred tax assets relating to these assets. If the Company's assumptions change, the Company may be able to realize these NOLs. The state and local loss carryforwards expire at various dates through 2032.
	As of December 31, 2013, the Company is subject to examination by the IRS for the years 2009 through 2013.
	The Company did not have any material unrecognized tax benefits at December 31, 2013 and 2012. It is the Company's accounting policy to record income tax interest and penalties in the income tax provision. See “Note 1—Summary of Significant Accounting Policies—Income Taxes.”

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2013
Goodwill [Abstract]	'
Goodwill	'
	8.       GOODWILL
	Goodwill is related to the Asset Management segment and totaled $36.0 million at both December 31, 2013 and 2012. Goodwill is not amortized and is tested at least annually for impairment. If indicators of impairment appear throughout the year, or in the event of material changes in circumstances, the test will be more frequent. The Company performs a step-one test and compares the carrying value of the tested assets with the fair value of the assets. Fair value is measured using a combination of the income approach and the market approach. The income approach consists of utilizing the discounted cash flow method that incorporates the Company's estimates of future revenues and costs, discounted using a market participant weighted-average cost of capital. The estimates the Company uses in the income approach are consistent with the plans and estimates that the Company uses to manage its operations. The market approach utilizes multiples of profit measures in order to estimate the fair value of the assets. As the income approach more closely aligns with how the Company internally evaluates and manages its business, the Company weights the income approach more heavily than the market approach in determining the fair value of the assets. However, the Company performs testing to ensure that both models are providing reasonably consistent results. Additionally, the Company performs sensitivity analysis on the key input factors in these models to determine whether any input factor or combination of factors moving moderately in either direction would change the results of these tests. Through the performance of these tests, the Company determined the fair value of goodwill substantially exceeded the carrying value, and concluded that it was not impaired as of December 31, 2013.

Fair_Value

Fair Value	12 Months Ended
	Dec. 31, 2013
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation Abstract	'
Fair Value	'
	9.       FAIR VALUE
	Assets and liabilities recorded at fair value are disclosed using a three-level hierarchy. The classification of assets and liabilities within the hierarchy is based on whether the inputs to the valuation methodology used for measurement are observable or unobservable. Observable inputs reflect market-derived or market-based information obtained from independent sources while unobservable inputs reflect the Company's estimates about market data.
	The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three broad levels: Level 1 inputs are based upon quoted prices in active markets for identical assets or liabilities that the Company can access at the measurement date. Level 2 inputs are based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market. Level 3 inputs are generated from model-based techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect the Company's estimates of assumptions that market participants would use in pricing the asset or liability.
	There are three types of valuation techniques used to measure assets and liabilities recorded at fair value:
	The market approach, which uses prices or other relevant information generated by market transactions involving identical or comparable assets or liabilities.
	The income approach, which uses the present value of cash flows or earnings.
	The cost approach, which uses replacement costs more readily adaptable for valuing physical assets.
	The Company uses both the market and income approach in its fair value measurements. These measurements are discussed in more detail below.
	The following tables set forth the estimated fair value and the carrying value of each financial instrument:
							31-Dec-13
							Carrying			Fair
	(In millions)						Value			Value			Level 1		Level 2		Level 3
	Assets:
		Fixed maturity securities:
			Corporate bonds				$	6,545.70		$	6,545.70		$	0	$	6,429.70	$	116
			U.S. government and agency bonds					353.2			353.2			0		353.2		0
			U.S. state and political subdivision bonds					140.3			140.3			0		140.3		0
			Foreign government bonds					65.5			65.5			0		65.5		0
			S&P 500 Index options					15.8			15.8			0		0		15.8
				Total fixed maturity securities			$	7,120.50		$	7,120.50		$	0	$	6,988.70	$	131.8
		Commercial mortgage loans, net					$	5,405.10		$	5,769.60		$	0	$	0	$	5,769.60
		Policy loans						2.5			2.5			0		0		2.5
		Separate account assets						6,393.20			6,393.20			6,249.20		144		0
	Liabilities:
		Total other policyholder funds, investment
			type contracts				$	5,469.80		$	5,632.70		$	0	$	0	$	5,632.70
		Index-based interest guarantees						67.6			67.6			0		0		67.6
		Short-term debt						1.5			1.9			0		1.9		0
		Long-term debt						551.9			553.6			0		553.6		0
							31-Dec-12
							Carrying			Fair
	(In millions)						Value			Value			Level 1		Level 2		Level 3
	Assets:
		Fixed maturity securities:
			Corporate bonds				$	6,525.90		$	6,525.90		$	0	$	6,445.50	$	80.4
			U.S. government and agency bonds					413			413			0		411.9		1.1
			U.S. state and political subdivision bonds					168.4			168.4			0		166.7		1.7
			Foreign government bonds					72.1			72.1			0		72.1		0
			S&P 500 Index options					11.3			11.3			0		0		11.3
				Total fixed maturity securities			$	7,190.70		$	7,190.70		$	0	$	7,096.20	$	94.5
		Commercial mortgage loans, net					$	5,267.40		$	5,946.30		$	0	$	0	$	5,946.30
		Policy loans						2.5			2.5			0		0		2.5
		Separate account assets						5,154.30			5,154.30			5,007.50		146.8		0
	Liabilities:
		Total other policyholder funds, investment
			type contracts				$	4,916.70		$	5,331.30		$	0	$	0	$	5,331.30
		Index-based interest guarantees						57.4			57.4			0		0		57.4
		Short-term debt						1			1.2			0		1.2		0
		Long-term debt						551.4			567.4			0		567.4		0
	Financial Instruments Not Recorded at Fair Value
	The Company did not elect to measure and record commercial mortgage loans, policy loans, other policyholders funds that are investment-type contracts, short-term debt, or long-term debt at fair value on the consolidated balance sheets.
	For disclosure purposes, the fair values of commercial mortgage loans were estimated using an option-adjusted discounted cash flow valuation. The valuation includes both observable market inputs and estimated model parameters.
	Significant observable inputs to the valuation include:
	Indicative year-end pricing for a package of loans similar to those originated by the Company near year-end.
	U.S. Government treasury yields.
	Indicative yields from industrial bond issues.
	The contractual terms of nearly every mortgage subject to valuation.
	Significant estimated parameters include:
	A liquidity premium that is estimated from historical loan sales and is applied over and above base yields.
	Adjustments in interest rate spread based on an aggregate portfolio loan-to-value ratio, estimated from historical differential yields with respect to loan-to-value ratios.
	Projected prepayment activity.
	For policy loans, the carrying value represents historical cost but approximates fair value. While potentially financial instruments, policy loans are an integral component of the insurance contract and have no maturity date.
	The fair value of other policyholder funds that are investment-type contracts was calculated using the income approach in conjunction with the cost of capital method. The parameters used for discounting in the calculation were estimated using the perspective of the principal market for the contracts under consideration. The principal market consists of other insurance carriers with similar contracts on their books.
The fair value for long-term debt was predominantly based on quoted market prices as of December 31, 2013 and December 31, 2012, and trades occurring close to December 31, 2013 and December 31, 2012.
Financial Instruments Measured and Recorded at Fair Value
Fixed maturity securities, Standard & Poor's (“S&P”) 500 Index call options (“S&P 500 Index options”) and index-based interest guarantees embedded in indexed annuities (“index-based interest guarantees”) are recorded at fair value on a recurring basis. In the Company's consolidated statements of income and comprehensive income, unrealized gains and losses are reported in other comprehensive income for fixed maturity securities, in net investment income for S&P 500 Index options and in interest credited for index-based interest guarantees.
Separate account assets represent segregated funds held for the exclusive benefit of contract holders. The activities of the account primarily relate to participant-directed 401(k) contracts. Separate account assets are recorded at fair value on a recurring basis, with changes in fair value recorded in separate account liabilities. Separate account assets consist of mutual funds. The mutual funds' fair value is determined through Level 1 and Level 2 inputs. The majority of the separate account assets are valued using quoted prices in an active market with the remainder of the assets valued using quoted prices from an independent pricing service. The Company reviews the values obtained from the pricing service for reasonableness through analytical procedures and performance reviews.
Fixed maturity securities are comprised of the following classes:
Corporate bonds
U.S. government and agency bonds.
U.S. state and political subdivision bonds.
Foreign government bonds.
S&P 500 Index options.
The fixed maturity securities are diversified across industries, issuers and maturities. The Company calculates fair values for all classes of fixed maturity securities using valuation techniques described below. They are placed into three levels depending on the valuation technique used to determine the fair value of the securities.
The Company uses an independent pricing service to assist management in determining the fair value of these assets. The pricing service incorporates a variety of information observable in the market in its valuation techniques, including:
Reported trading prices.
Benchmark yields.
Broker-dealer quotes.
Benchmark securities.
Bids and offers.
Credit ratings.
Relative credit information.
Other reference data.
The pricing service also takes into account perceived market movements and sector news, as well as a bond's terms and conditions, including any features specific to that issue that may influence risk, and thus marketability. Depending on the security, the priority of the use of observable market inputs may change as some observable market inputs may not be relevant or additional inputs may be necessary. The Company generally obtains one value from its primary external pricing service. On a case-by-case basis, the Company may obtain further quotes or prices from additional parties as needed.
The pricing service provides quoted market prices when available. Quoted prices are not always available due to bond market inactivity. The pricing service obtains a broker quote when sufficient information, such as security structure or other market information, is not available to produce a valuation. Valuations and quotes obtained from third party commercial pricing services are non-binding and do not represent quotes on which one may execute the disposition of the assets.
The significant unobservable inputs used in the fair value measurement of the reporting entity's bonds are valuations and quotes received from secondary pricing service, analytical reviews and broker quotes. Significant increases or decreases in any of those inputs in isolation would result in a significantly lower or higher fair value measurement. Generally, a change in the assumption used for the pricing evaluation is accompanied by a directionally similar change in the assumption used for the methodologies.
The Company performs control procedures over the external valuations at least quarterly through a combination of procedures that include an evaluation of methodologies used by the pricing service, analytical reviews and performance analysis of the prices against statistics, trends and secondary pricing sources, back testing of sales activity and maintenance of a securities watch list. As necessary, the Company compares prices received from the pricing service to prices independently estimated by the Company utilizing discounted cash flow models or through performing independent valuations of inputs and assumptions similar to those used by the pricing service in order to ensure prices represent a reasonable estimate of fair value. Although the Company does identify differences from time to time as a result of these validation procedures, the Company did not make any significant adjustments as of December 31, 2013 or December 31, 2012.
S&P 500 Index options and certain fixed maturity securities were valued using Level 3 inputs. The Level 3 fixed maturity securities were valued using matrix pricing, independent broker quotes and other standard market valuation methodologies. The fair value was determined using inputs that were not observable or could not be derived principally from, or corroborated by, observable market data. These inputs included assumptions regarding liquidity, estimated future cash flows and discount rates. Unobservable inputs to these valuations are based on management's judgment or estimation obtained from the best sources available. The Company's valuations maximize the use of observable inputs, which include an analysis of securities in similar sectors with comparable maturity dates and bond ratings. Broker quotes are validated by management for reasonableness in conjunction with information obtained from matrix pricing and other sources.
The Company calculates the fair value for its S&P 500 Index options using the Black-Scholes option pricing model and parameters derived from market sources. The Company's valuations maximize the use of observable inputs, which include direct price quotes from the Chicago Board Options Exchange (“CBOE”) and values for on-the-run treasury securities and London Interbank Offered Rate (“LIBOR”) as reported by Bloomberg. Unobservable inputs are estimated from the best sources available to the Company and include estimates of future gross dividends to be paid on the stocks underlying the S&P 500 Index, estimates of bid-ask spreads, and estimates of implied volatilities on options. Valuation parameters are calibrated to replicate the actual end-of-day market quotes for options trading on the CBOE. The Company performs additional validation procedures such as the daily observation of market activity and conditions and the tracking and analyzing of actual quotes provided by banking counterparties each time the Company purchases options from them. Additionally, in order to help validate the values derived through the procedures noted above, the Company obtains indicators of value from representative investment banks.
The Company uses the income approach valuation technique to determine the fair value of index-based interest guarantees. The liability is the present value of future cash flows attributable to the projected index growth in excess of cash flows driven by fixed interest rate guarantees for the indexed annuity product. Level 3 assumptions for policyholder behavior and future index crediting rate declarations significantly influence the calculation. Index-based interest guarantees are included in the other policyholder funds line on the Company's consolidated balance sheet.
While valuations for the S&P 500 Index options are sensitive to a number of variables, valuations for S&P 500 Index options purchased are most sensitive to changes in the estimates of bid ask spreads, or the S&P 500 Index value, and the implied volatilities of this index. Significant fluctuations in any of those inputs in isolation would result in a significantly lower or higher fair value measurement. Generally, an increase or decrease used in the assumption for the implied volatilities and in the S&P 500 Index value would result in a directionally similar change in the fair value of the asset.
Valuations for the index-based interest guarantees are sensitive to a number of variables, but are most sensitive to the S&P 500 Index value, the implied volatilities of this index, and the interest rate environment. Generally, a significant increase or decrease used in the assumption for the implied volatilities and in the S&P 500 Index value would result in a directionally similar change, while an increase or decrease in the interest rate environment would result in a directionally opposite change in the fair value of the liability.
Valuations for commercial mortgage loans measured at fair value on a nonrecurring basis using significant unobservable Level 3 inputs are sensitive to a number of variables, but are most sensitive to net operating income and the applied capitalization rate. Generally, an increase or decrease resulting from a change in the stabilized net operating income from the collateralized property would result in a directionally similar change in the fair value of the asset. An increase or decrease in the assumption for the capitalization rate would result in a directionally opposite change in the fair value of the asset.
Valuations for Real Estate Owned measured at fair value on a nonrecurring basis using significant unobservable Level 3 inputs are sensitive to a number of variables. They are most sensitive to the reductions taken on appraisals obtained, which may result in a fair value and carrying value below the appraised value. Generally, an increase in the reductions taken on appraisals obtained would result in a reduction in the fair value of the asset.
The following table sets forth quantitative information regarding significant unobservable inputs used in Level 3 valuation of assets and liabilities measured and recorded at fair value:
							31-Dec-13					31-Dec-12
							Fair			Range		Fair		Range
(Dollars in millions)			Valuation Technique		Unobservable Input		Value			of inputs		Value		of inputs
S&P 500 Index options			Black-Scholes option pricing model		Various assumptions		$	15.8		(a)		$	11.3	(a)
Index-based interest			Discounted cash		Expected future		$	67.6		1% - 6%		$	57.4	1% - 5%
	guarantees		flow		option purchase
					Various assumptions					(b)				(b)
			Black-Scholes option pricing model		Various assumptions					(a)				(a)
Commercial mortgage loans			Appraisals		Reduction on appraisal		$	68.7		0% - 13%		$	53.9	0% - 38%
			Cash flows		Capitalization rate (c)					7% - 16%				7% - 14%
Real Estate Owned			Appraisals		Reduction on appraisal		$	35.2		0%- 53%		$	48.2	0%- 36%
Represents various assumptions derived from market data, which include estimates of bid ask spreads and the implied volatilities for the S&P 500 Index.
Represents various actuarial assumptions which include combined lapse, mortality and withdrawal decrement rates which generally have a range of inputs from 5%-36% for both December 31, 2013 and December 31, 2012.
Capitalization rates are used as an internal analysis in converting the underlying property's income to an estimated property value.
The following tables set forth the reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable Level 3 inputs:
			Year ended December 31, 2013
			Assets													Liabilities
			U.S.			U.S. State										Index-
			Government			and Political						S&P 500				Based
			and Agency			Subdivision			Corporate			Index		Total		Interest
(In millions)			Bonds			Bonds			Bonds			Options		Assets		Guarantees
Beginning balance			$	1.1		$	1.7		$	80.4		$	11.3	$	94.5	$	57.4
Total realized/unrealized gains (losses):
	Included in net income			0			0			0			14.4		14.4		9
	Included in other comprehensive income (loss)			0			0			6.2			0		6.2		0
Purchases, issuances, sales and settlements:
	Purchases			0			0			0			9.4		9.4		0
	Issuances			0			0			0			0		0		6
	Sales			0			0			0			0		0		0
	Settlements			0			0			0			-19.3		-19.3		-4.8
Transfers into level 3				0			0			61.6			0		61.6		0
Transfers out of level 3				-1.1			-1.7			-32.2			0		-35		0
Ending balance			$	0		$	0		$	116		$	15.8	$	131.8	$	67.6
			Year ended December 31, 2012
			Assets													Liabilities
			U.S.			U.S. State										Index-
			Government			and Political						S&P 500				Based
			and Agency			Subdivision			Corporate			Index		Total		Interest
(In millions)			Bonds			Bonds			Bonds			Options		Assets		Guarantees
Beginning balance			$	0.5		$	1.4		$	64		$	7.2	$	73.1	$	49.5
Total realized/unrealized gains (losses):
	Included in net income			0			0			0			7.8		7.8		6.4
	Included in other comprehensive income (loss)			0			-0.1			8			0		7.9		0
Purchases, issuances, sales and settlements:
	Purchases			1.1			0			12.1			9.5		22.7		0
	Issuances			0			0			0			0		0		4.9
	Sales			0			0			-2.2			0		-2.2		0
	Settlements			0			0			0			-13.2		-13.2		-3.4
Transfers into level 3				0			0.4			8			0		8.4		0
Transfers out of level 3				-0.5			0			-9.5			0		-10		0
Ending balance			$	1.1		$	1.7		$	80.4		$	11.3	$	94.5	$	57.4
For all periods disclosed above, fixed maturity securities transferred into Level 3 from Level 2 are the result of the Company being unable to obtain observable assumptions for these investments in the market. Fixed maturity securities transferred out of Level 3 into Level 2 are the result of the Company being able to obtain observable assumptions for these investments in the market. There were no transfers between Level 1 and Level 2 for 2013 and 2012.
The following table sets forth the changes in unrealized gains (losses) included in net income relating to positions that the Company continued to hold:
		Years ended
		December 31,
(In millions)		2013			2012
Assets:
	S&P 500 Index options	$	6.4		$	1.8
Liabilities:
	Index-based interest guarantees	$	-12.9		$	-7.8
Changes to the fair value of fixed maturity securities, excluding S&P 500 Index options, were recorded in other comprehensive income. Changes to the fair value of the S&P 500 Index options were recorded to net investment income. Changes to the fair value of the index-based interest guarantees were recorded to interest credited and are sensitive to a number of variables and assumptions. The increase in unrealized losses for the index-based guarantee liability for 2013 was due to a change in the interest rate environment. The interest credited amount for 2013 and 2012 included negative interest on policyholder funds of $4.1 million and $3.3 million, respectively, due to changes in the Level 3 actuarial assumptions.
Certain assets and liabilities are measured at fair value on a nonrecurring basis such as impaired commercial mortgage loans with specific allowances for losses and Real Estate Owned. The impaired commercial mortgage loans and Real Estate Owned are valued using Level 3 measurements. These Level 3 inputs are reviewed for reasonableness by management and evaluated on a quarterly basis. The commercial mortgage loan measurements include valuation of the market value of the asset using general underwriting procedures and appraisals. Real Estate Owned is initially recorded at net realizable value, which includes an estimate for disposal costs. These amounts may be adjusted in a subsequent period as additional information is received.
The following table sets forth the assets measured at fair value on a nonrecurring basis as of December 31, 2013 that the Company continued to hold:
		31-Dec-13
(In millions)		Total			Level 1			Level 2			Level 3
Commercial mortgage loans		$	68.7		$	0		$	0		$	68.7
Real Estate Owned			35.2			0			0			35.2
	Total assets measured at fair value on a nonrecurring basis	$	103.9		$	0		$	0		$	103.9
Commercial mortgage loans measured on a nonrecurring basis with a carrying amount of $87.7 million were written down to their fair value of $68.7 million, less selling costs, at December 31, 2013. The specific commercial mortgage loan loss allowance related to these commercial mortgage loans was $25.9 million at December 31, 2013. The Real Estate Owned measured on a nonrecurring basis as of December 31, 2013, and still held at December 31, 2013 had capital losses totaling $7.2 million for 2013. Real Estate Owned measured on a nonrecurring basis represents newly acquired properties or properties whose value has been adjusted based on pending sale or other market information.
The following table sets forth the assets measured at fair value on a nonrecurring basis as of December 31, 2012 that the Company continued to hold:
		31-Dec-12
(In millions)		Total			Level 1			Level 2			Level 3
Commercial mortgage loans		$	53.9		$	0		$	0		$	53.9
Real Estate Owned			48.2			0			0			48.2
	Total assets measured at fair value on a nonrecurring basis	$	102.1		$	0		$	0		$	102.1
Commercial mortgage loans measured on a nonrecurring basis with a carrying amount of $74.1 million were written down to their fair value of $53.9 million, less selling costs, at December 31, 2012. The specific commercial mortgage loan loss allowance related to these commercial mortgage loans was $25.6 million at December 31, 2012. The Real Estate Owned measured on a nonrecurring basis as of December 31, 2012 and still held at December 31, 2012 had capital losses totaling $2.1 million for 2012. See “Note 10—Investments—Commercial Mortgage Loans” for further disclosures regarding the commercial mortgage loan loss allowance.

Investments

Investments	12 Months Ended
	Dec. 31, 2013
Investments [Abstract]	'
Investments	'
	10.       INVESTMENTS
	Fixed Maturity Securities
	The following tables set forth amortized costs, gross unrealized gains and losses and fair values of the Company's fixed maturity securities:
			December 31,
			2013
			Amortized			Unrealized			Unrealized			Fair
	(In millions)		Cost			Gains			Losses			Value
	Corporate bonds		$	6,282.10		$	339.6		$	-76		$	6,545.70
	U.S. government and agency bonds			320.8			32.8			-0.4			353.2
	U.S. state and political subdivision bonds			134.3			6.8			-0.8			140.3
	Foreign government bonds			58.9			6.6			0			65.5
	S&P 500 Index options			15.8			0			0			15.8
		Total fixed maturity securities	$	6,811.90		$	385.8		$	-77.2		$	7,120.50
			December 31,
			2012
			Amortized			Unrealized			Unrealized			Fair
	(In millions)		Cost			Gains			Losses			Value
	Corporate bonds		$	5,942.00		$	587.7		$	-3.8		$	6,525.90
	U.S. government and agency bonds			351.5			61.5			0			413
	U.S. state and political subdivision bonds			151.6			16.8			0			168.4
	Foreign government bonds			61.3			10.8			0			72.1
	S&P 500 Index options			11.3			0			0			11.3
		Total fixed maturity securities	$	6,517.70		$	676.8		$	-3.8		$	7,190.70
	The following table sets forth the amortized costs and fair values of the Company's fixed maturity securities by contractual maturity:
			31-Dec-13						31-Dec-12
			Amortized			Fair			Amortized			Fair
	(In millions)		Cost			Value			Cost			Value
	Due in one year or less		$	486.2		$	495.1		$	699.2		$	712.9
	Due after one year through five years			2,974.50			3,168.90			2,779.90			3,009.10
	Due after five years through ten years			2,497.50			2,524.60			2,184.70			2,422.60
	Due after ten years			853.7			931.9			853.9			1,046.10
		Total fixed maturity securities	$	6,811.90		$	7,120.50		$	6,517.70		$	7,190.70
	Actual maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations. Callable bonds, excluding bonds with make-whole provisions and bonds with provisions that allow the borrower to prepay near maturity, represented 4.25%, or $302.8 million, of the Company's fixed maturity securities portfolio at December 31, 2013. At December 31, 2013, the Company did not have any direct exposure to sub-prime or Alt-A mortgages in its fixed maturity securities portfolio. At December 31, 2013, the Company did not have any direct exposure to euro zone government issued debt or debt issued by investment and commercial banks headquartered in Portugal, Ireland, Italy, Greece or Spain. At December 31, 2013, fixed maturity securities issued by investment and commercial banks headquartered in other euro zone countries represented 0.9%, or $60.7 million, of the Company's fixed maturity securities portfolio. There were no impairments on the fixed maturity securities with euro zone exposure in 2013.
	Gross Unrealized Losses
	The following tables set forth the gross unrealized losses and fair value of investments, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position:
					31-Dec-13
					Total						Less than 12 months						12 or more months
	(Dollars in millions)				Number			Amount			Number			Amount			Number			Amount
	Unrealized losses:
			U.S. state and political subdivision bonds			10		$	0.8			10		$	0.8			0		$	0
			U.S. government and agency bonds			9			0.4			9			0.4			0			0
			Corporate bonds			908			76			848			66.3			60			9.7
				Total		927		$	77.2			867		$	67.5			60		$	9.7
	Fair market value of securities with
		unrealized losses:
			U.S. state and political subdivision bonds			10		$	15.4			10		$	15.4			0		$	0
			U.S. government and agency bonds			9			16.9			9			16.9			0			0
			Corporate bonds			908			1,663.80			848			1,557.70			60			106.1
				Total		927		$	1,696.10			867		$	1,590.00			60		$	106.1
					31-Dec-12
					Total						Less than 12 months						12 or more months
	(Dollars in millions)				Number			Amount			Number			Amount			Number			Amount
	Unrealized losses:
			Corporate bonds			198		$	3.8			188		$	3.6			10		$	0.2
	Fair market value of securities with
		unrealized losses:
			Corporate bonds			198		$	342.5			188		$	335.5			10		$	7
	The unrealized losses on the investment securities set forth above were partly due to increases in market interest rates subsequent to their purchase by the Company and have also been affected by overall economic factors. The Company expects the fair value of these investment securities to recover as the investment securities approach their maturity dates or sooner if market yields for such investment securities decline. The Company does not believe that any of the investment securities are impaired due to credit quality or due to any company or industry specific event. Based on management's evaluation of the securities and the Company's intent to hold the securities, and as it is unlikely that the Company will be required to sell the securities, none of the unrealized losses summarized in this table are considered other-than-temporary. See “Note 1—Summary of Significant Accounting Policies—Investment Valuations—Fixed Maturity Securities” for a discussion regarding fixed maturity securities' OTTI.
	Commercial Mortgage Loans
	The Company underwrites mortgage loans on commercial property throughout the United States. In addition to real estate collateral, the Company requires either partial or full recourse on most loans. At December 31, 2013, the Company did not have any direct exposure to sub-prime or Alt-A mortgages in its commercial mortgage loan portfolio.
	The following table sets forth the commercial mortgage loan portfolio by property type, by geographic region within the U.S. and by U.S. state:
				31-Dec-13						31-Dec-12
	(Dollars in millions)			Amount			Percent			Amount			Percent
Property type:
	Retail		$	2,629.20		48.6	%		$	2,560.70		48.6	%
	Industrial			1,008.70		18.7				995.8		18.9
	Office			982.4		18.2				960.8		18.2
	Hotel/motel			276.3		5.1				280.8		5.3
	Commercial			218.6		4				205.3		4
	Apartment and other			289.9		5.4				264		5
		Total commercial mortgage loans, net	$	5,405.10		100	%		$	5,267.40		100	%
Geographic region*:
	Pacific		$	1,910.10		35.3	%		$	1,844.10		35	%
	South Atlantic			1,090.00		20.2				1,069.20		20.2
	West South Central			672.8		12.4				634.8		12.1
	Mountain			611.4		11.3				612.7		11.6
	East North Central			473.8		8.8				443.9		8.4
	Middle Atlantic			223		4.1				240.3		4.6
	West North Central			186.9		3.5				183		3.5
	East South Central			166.6		3.1				150.5		2.9
	New England			70.5		1.3				88.9		1.7
		Total commercial mortgage loans, net	$	5,405.10		100	%		$	5,267.40		100	%
U.S. state:
	California		$	1,455.50		26.9	%		$	1,436.30		27.3	%
	Texas			618.8		11.5				587		11.1
	Florida			331.6		6.1				331.9		6.3
	Georgia			310.7		5.8				311.5		5.9
	Other states			2,688.50		49.7				2,600.70		49.4
		Total commercial mortgage loans, net	$	5,405.10		100	%		$	5,267.40		100	%
*        Geographic regions obtained from the American Council of Life Insurers Mortgage Loan Portfolio Profile.
Due to the concentration of commercial mortgage loans in California, the Company could be exposed to potential losses as a result of an economic downturn in California as well as certain catastrophes, such as earthquakes and fires, which may affect the region.
The carrying value of commercial mortgage loans represents the outstanding principal balance less a loan loss allowance for probable uncollectible amounts. The commercial mortgage loan loss allowance is estimated based on evaluating known and inherent risks in the loan portfolio and consists of a general and a specific loan loss allowance.
Impairment Evaluation
The Company continuously monitors its commercial mortgage loan portfolio for potential impairment by evaluating the portfolio and individual loans. See “Note 1—Summary of Significant Accounting Policies—Investment Valuations—Commercial Mortgage Loans” for the Company's commercial mortgage loan impairment evaluation.
General Loan Loss Allowance
The general loan loss allowance is based on the Company's analysis of factors including changes in the size and composition of the loan portfolio, debt coverage ratios, loan to value ratios, actual loan loss experience and individual loan analysis.
Specific Loan Loss Allowance
An impaired commercial mortgage loan is a loan where the Company does not expect to receive contractual principal and interest in accordance with the terms of the original loan agreement. A specific allowance for losses is recorded when a loan is considered to be impaired and it is probable that all amounts due will not be collected based on the terms of the original note. The Company also holds specific loan loss allowances on certain performing commercial mortgage loans that it continues to monitor and evaluate. Impaired commercial mortgage loans without specific allowances for losses are those for which the Company has determined that it remains probable that all amounts due will be collected although the timing or nature may be outside the original contractual terms. In addition, for impaired commercial mortgage loans, the Company evaluates the cost to dispose of the underlying collateral, any significant out of pocket expenses the loan may incur and other quantitative information management has concerning the loan. Portions of loans that are deemed uncollectible are written off against the allowance, and recoveries, if any, are credited to the allowance.
The following table sets forth changes in the commercial mortgage loan loss allowance:
			Years ended
			December 31,
(In millions)			2013			2012
Commercial mortgage loan loss allowance:
Beginning balance			$	46.6		$	48.1
	Provision			15.9			13.4
	Charge-offs, net			-18.9			-14.9
		Ending balance	$	43.6		$	46.6
Specific loan loss allowance			$	25.9		$	25.6
General loan loss allowance				17.7			21
		Total commercial mortgage loan loss allowance	$	43.6		$	46.6
The decrease in the commercial mortgage loan loss allowance for 2013 compared to 2012 was primarily due to the decrease in the general loan loss allowance which was driven by improvement in the composition of the commercial mortgage loan portfolio that impacts the general loan loss allowance. This decrease was partially offset by an increase to the specific loan loss allowance. The increase in charge-offs was primarily due to higher losses related to foreclosures, accepted deeds in lieu of foreclosure on commercial mortgage loans and other related charges associated with commercial mortgage loans leaving the portfolio for 2013.
The following table sets forth the recorded investment in commercial mortgage loans:
			December 31,
(In millions)			2013			2012
Commercial mortgage loans collectively evaluated for impairment			$	5,334.40		$	5,214.20
Commercial mortgage loans individually evaluated for impairment				114.3			99.8
Commercial mortgage loan loss allowance				-43.6			-46.6
		Total commercial mortgage loans, net	$	5,405.10		$	5,267.40
The Company assesses the credit quality of its commercial mortgage loan portfolio quarterly by reviewing the performance of its portfolio which includes evaluating its performing and nonperforming commercial mortgage loans. Nonperforming commercial mortgage loans include all commercial mortgage loans that are 60 days or more past due and commercial mortgage loans that are not 60 days past due but are not substantially performing to other original contractual terms.
The following tables set forth performing and nonperforming commercial mortgage loans by property type:
			31-Dec-13
												Hotel/						Apartment
(In millions)			Retail			Industrial			Office			Motel			Commercial			and Other			Total
Performing commercial mortgage
	loans		$	2,624.20		$	1,004.60		$	979.6		$	276.3		$	218.6		$	289.9		$	5,393.20
Nonperforming commercial
	mortgage loans			5			4.1			2.8			0			0			0			11.9
		Total commercial mortgage loans	$	2,629.20		$	1,008.70		$	982.4		$	276.3		$	218.6		$	289.9		$	5,405.10
			31-Dec-12
												Hotel/						Apartment
(In millions)			Retail			Industrial			Office			Motel			Commercial			and Other			Total
Performing commercial mortgage
	loans		$	2,552.50		$	993		$	955.8		$	280.8		$	204.7		$	263.5		$	5,250.30
Nonperforming commercial
	mortgage loans			8.2			2.8			5			0			0.6			0.5			17.1
		Total commercial mortgage loans	$	2,560.70		$	995.8		$	960.8		$	280.8		$	205.3		$	264		$	5,267.40
The following tables set forth impaired commercial mortgage loans identified in management's specific review of probable loan losses and the related allowance:
						31-Dec-13
									Unpaid						Amount on
						Recorded			Principal			Related			Nonaccrual
(In millions)						Investment			Balance			Allowance			Status
Impaired commercial mortgage loans:
	Without specific loan loss allowances:
		Retail				$	16.1		$	16.1		$	0		$	7.6
		Office					3.9			3.9			0			1.5
		Industrial					1			1			0			0
		Commercial					1.8			1.8			0			0
		Apartment and other					3.8			3.8			0			0
			Total impaired commercial mortgage loans without specific
				loan loss allowances			26.6			26.6			0			9.1
	With specific loan loss allowances:
		Retail					58.5			58.5			16.1			21.6
		Office					9.7			9.7			3.8			0.9
		Industrial					12.6			12.6			2.4			1.4
		Commercial					6			6			3.6			2.5
		Apartment and other					0.9			0.9			0			0
			Total impaired commercial mortgage loans with specific
				loan loss allowances			87.7			87.7			25.9			26.4
					Total impaired commercial mortgage loans	$	114.3		$	114.3		$	25.9		$	35.5
						31-Dec-12
									Unpaid						Amount on
						Recorded			Principal			Related			Nonaccrual
(In millions)						Investment			Balance			Allowance			Status
Impaired commercial mortgage loans:
	Without specific loan loss allowances:
		Retail				$	15.3		$	15.3		$	0		$	2.2
		Office					5.2			5.2			0			4.1
		Industrial					3.3			3.3			0			0.2
		Apartment and other					1.9			1.9			0			0
			Total impaired commercial mortgage loans without specific
				loan loss allowances			25.7			25.7			0			6.5
	With specific loan loss allowances:
		Retail					37.9			37.9			13.2			9.3
		Office					10.3			10.3			2.5			1.3
		Industrial					11.4			11.4			3.6			2
		Commercial					11.4			11.4			6.2			2.7
		Apartment and other					3.1			3.1			0.1			0
			Total impaired commercial mortgage loans with specific
				loan loss allowances			74.1			74.1			25.6			15.3
					Total impaired commercial mortgage loans	$	99.8		$	99.8		$	25.6		$	21.8
The increase in the carrying value of impaired commercial mortgage loans at December 31, 2013 compared to December 31, 2012 was primarily due to an increase in commercial mortgage loans with a specific loan loss allowance within the Company's retail segment during 2013. As of December 31, 2013 and December 31, 2012 the Company did not have any commercial mortgage loans greater than 90 days delinquent that were accruing interest. See “Note 1—Summary of Significant Accounting Policies—Investment Valuations—Commercial Mortgage Loans” for the policies regarding interest income for delinquent commercial mortgage loans.
A modification is considered to be a troubled debt restructuring when the debtor is experiencing financial difficulties and the restructured terms constitute a concession. Granting payment forbearance is not a modification of the loan if the payment forbearance is considered to be an insignificant timing difference associated with the borrowing. The Company evaluates all restructured commercial mortgage loans for indications of troubled debt restructurings and the potential losses related to these restructurings. If a loan is considered a troubled debt restructuring, the Company impairs the loan and records a specific allowance for estimated losses. In some cases, the recorded investment in the loan may increase post-restructuring. The Company assessed all restructurings that occurred during the period to determine if they were troubled debt restructurings. The Company did not identify any troubled debt restructurings that were not already considered impaired.
The following tables set forth information related to the troubled debt restructurings of financing receivables:
						Year ended
						31-Dec-13
									Pre-			Post-
									Restructuring			Restructuring
						Number of			Recorded			Recorded
(Dollars in millions)						Loans			Investment			Investment
Troubled debt restructurings:
		Retail					16		$	20		$	20.8
		Office					3			1.6			1.6
		Industrial					2			2.2			2.3
		Commercial					1			0.9			0.9
			Total troubled debt restructurings				22		$	24.7		$	25.6
						Year ended
						31-Dec-12
									Pre-			Post-
									Restructuring			Restructuring
						Number of			Recorded			Recorded
(Dollars in millions)						Loans			Investment			Investment
Troubled debt restructurings:
		Retail					8		$	8		$	9.2
		Industrial					3			2.4			2.4
		Commercial					1			1			1
		Apartment and other					1			1.8			1.9
			Total troubled debt restructurings				13		$	13.2		$	14.5
There were no troubled debt restructurings identified in the previous 12 months that subsequently defaulted during 2013.
The following table sets forth the average recorded investment in impaired commercial mortgage loans before specific allowances for losses:
	Years ended December 31,
(In millions)	2013			2012			2011
Average recorded investment	$	113.4		$	101.3		$	92.3
The amount of interest income recognized on impaired commercial mortgage loans was $4.2 million, $4.1 million and $3.8 million for 2013, 2012 and 2011, respectively. The cash received by the Company in payment of interest on impaired commercial mortgage loans was $3.8 million, $4.0 million and $3.1 million for 2013, 2012 and 2011, respectively. See “Note 1—Summary of Significant Accounting Policies—Investment Valuations—Commercial Mortgage Loans” for policies regarding interest income for delinquent commercial mortgage loans.
The following tables set forth the aging of commercial mortgage loans by property type:
			31-Dec-13
																					Total
									Greater Than						Allowance						Commercial
			30 Days			60 Days			90 Days			Total			Related			Current,			Mortgage
(In millions)			Past Due			Past Due			Past Due			Past Due			to Past Due			Net			Loans
Commercial mortgage loans:
	Retail		$	2.8		$	0.3		$	6.1		$	9.2		$	-1.5		$	2,621.50		$	2,629.20
	Office			1.3			0			3.7			5			-0.9			978.3			982.4
	Industrial			0			3.3			1.8			5.1			-0.9			1,004.50			1,008.70
	Hotel/motel			6.3			0			0			6.3			0			270			276.3
	Commercial			0			0			0			0			0			218.6			218.6
	Apartment and other			0			0			0			0			0			289.9			289.9
		Total commercial mortgage loans	$	10.4		$	3.6		$	11.6		$	25.6		$	-3.3		$	5,382.80		$	5,405.10
			31-Dec-12
																					Total
									Greater Than						Allowance						Commercial
			30 Days			60 Days			90 Days			Total			Related			Current,			Mortgage
(In millions)			Past Due			Past Due			Past Due			Past Due			to Past Due			Net			Loans
Commercial mortgage loans:
	Retail		$	17.2		$	4.9		$	4.7		$	26.8		$	-1.4		$	2,535.30		$	2,560.70
	Office			4.1			0			5.6			9.7			-0.6			951.7			960.8
	Industrial			1.6			0.5			3.6			5.7			-1.4			991.5			995.8
	Hotel/motel			0			0			0			0			0			280.8			280.8
	Commercial			2.7			0			1.4			4.1			-0.8			202			205.3
	Apartment and other			0			0.6			0			0.6			0			263.4			264
		Total commercial mortgage loans	$	25.6		$	6		$	15.3		$	46.9		$	-4.2		$	5,224.70		$	5,267.40
The Company closely monitors all past due commercial mortgage loans. Additional attention is given to those loans at least 60 days past due. Commercial mortgage loans that have been granted forbearance are not considered to be past due. Commercial mortgage loans that were at least 60 days past due totaled $15.2 million and $21.3 million at December 31, 2013 and 2012, respectively. The Company's current level of past due commercial mortgage loans is lower than its historical levels due to an improving commercial real estate market. Commercial mortgage loans that were at least 60 days past due were 0.28% of the commercial mortgage loan portfolio at December 31, 2013, compared to 0.40% at December 31, 2012.
Net Investment Income
The following table sets forth net investment income summarized by investment type:
					Years ended
					December 31,
(In millions)						2013			2012		2011
Fixed maturity securities:
	Bonds				$	303		$	316.8		$	323.6
	S&P 500 Index options					14.4			7.8			-0.2
		Total fixed maturity securities				317.4			324.6			323.4
Commercial mortgage loans						341.7			331.9			310.2
Real estate						-1.4			-1			-0.4
Other						9			8.6			8
			Gross investment income			666.7			664.1			641.2
Investment expenses						-22.9			-22.3			-21.8
Tax-advantaged investment operating losses						-13.9			-13.3			-6.6
				Net investment income	$	629.9		$	628.5		$	612.8
Realized Gross Capital Gains and Losses
The following table sets forth gross capital gains and losses by investment type:
				Years ended
				December 31,
(In millions)				2013			2012			2011
Gains:
	Fixed maturity securities			$	9.8		$	10.8		$	11.5
	Commercial mortgage loans				2.4			1.5			0.9
	Real estate investments				0.7			---			35.2
	Real estate owned				2.3			1.3			1.1
	Other				0.2			0.6			0
		Gross capital gains			15.4			14.2			48.7
Losses:
	Fixed maturity securities				-2.3			-5			-2.4
	Provision for commercial mortgage loan losses				-15.9			-13.4			-32.7
	Real estate investments				-0.1			0			-0.5
	Real estate owned				-9.5			-3.5			-17.6
	Other				-3.3			-1			-2.4
		Gross capital losses			-31.1			-22.9			-55.6
			Net capital losses	$	-15.7		$	-8.7		$	-6.9
Securities Deposited as Collateral
Securities deposited for the benefit of policyholders in various states, in accordance with state regulations, amounted to $7.4 million and $7.9 million at December 31, 2013 and 2012, respectively.

Derivative_Financial_Instrumen

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2013
Derivative Financial Instruments [Abstract]	'
Derivative Financial Instruments	'
	11.        DERIVATIVE FINANCIAL INSTRUMENTS
	The Company sells indexed annuities, which permit the holder to elect a fixed interest rate return or an indexed return, where interest credited to the contracts is based on the performance of the S&P 500 Index, subject to an upper limit or cap and minimum guarantees. Policyholders may elect to rebalance between interest crediting options at renewal dates annually. At each renewal date, the Company has the opportunity to re-price the indexed component by changing the cap, subject to minimum guarantees. The Company estimates the fair value of the index-based interest guarantees for the current period and for all future reset periods until contract maturity. Changes in the fair value of the index-based interest guarantees are recorded as interest credited. The liability represents an estimate of the cost of the options to be purchased in the future to manage the risk related to the index-based interest guarantees. The liability for index-based interest guarantees is the present value of future cash flows attributable to the projected index growth that is in excess of cash flows attributable to fixed interest rates guarantees. The excess cash flows are discounted back to the date of the balance sheet using current market indicators for future interest rates and option costs. Cash flows depend on actuarial estimates for policyholder lapse behavior and management's discretion in setting renewal index-based interest guarantees.
	The Company purchases S&P 500 Index options for its interest crediting strategy used in its indexed annuity product. The S&P 500 Index options are purchased from investment banks and are selected in a manner that supports the amount of interest that is expected to be credited in the current year to annuity policyholder accounts that are dependent on the performance of the S&P 500 Index. The purchase of S&P 500 Index options is a pivotal part of the Company's risk management strategy for indexed annuity products. The S&P 500 Index options are exclusively used for risk management. While valuations of the S&P 500 Index options are sensitive to a number of variables, valuations for S&P 500 Index options purchased are most sensitive to changes in the S&P 500 Index value and the implied volatilities of this index. The Company generally purchases one S&P 500 Index option contract per month, which has an expiry date of one year from the date of purchase.
	The notional amount of the Company's S&P 500 Index options at December 31, 2013 and 2012 was $350.5 million and $315.2 million, respectively. Option premiums paid for the Company's S&P 500 Index option contracts were $9.4 million and $9.5 million for 2013 and 2012, respectively. The Company received $19.3 million and $13.2 million for options exercised in 2013 and 2012, respectively.
	The Company recognizes all derivative instruments as assets or liabilities on the balance sheet at fair value. The Company does not currently designate its derivatives as hedging instruments and thus does not use hedge accounting. As such, any change in the fair value of the derivative assets and derivative liabilities is recognized as income or loss in the period of change. See “Note 9—Fair Value” for additional information regarding the fair value of the Company's derivative assets and liabilities.
	The following table sets forth the fair value of the Company's derivative assets and liabilities:
	Derivatives Not Designated as Hedging Instruments			December 31,
	(In millions)			2013		2012
	Assets:
		Fixed maturity securities:
			S&P 500 Index options	$	15.8	$	11.3
	Liabilities:
		Other policyholder funds:
			Index-based interest guarantees	$	67.6	$	57.4
	The following table sets forth the amount of gain or loss recognized in earnings from the change in fair value of the Company's derivative assets and liabilities:
	Derivatives Not Designated as Hedging Instruments			Years ended December 31,
	(In millions)			2013		2012		2011
	Net investment income:
		S&P 500 Index options		$	14.4	$	7.8	$	-0.2
	Interest credited:
		Index-based interest guarantees			-9		-6.4		-1.3
			Net gain (loss)	$	5.4	$	1.4	$	-1.5
	Fluctuations in the fair value of the S&P 500 Index options are primarily the result of volatility in the S&P 500 Index and are recorded to net investment income. Changes in the fair value of the index-based interest guarantees are sensitive to a number of variables, but are most sensitive to changes in the interest rate environment. As a result of the Company's annual update of the key assumptions used to value index-based interest guarantees, a process known as “unlocking,” interest credited decreased $4.1 million and $3.3 million for 2013 and 2012, respectively. The combined changes in fair value of the S&P 500 Index options and the index-based interest guarantees resulted in net gains for 2013 and 2012.
	The Company does not bear derivative-related risk that would require it to post collateral with another institution, and its index option contracts do not contain counterparty credit-risk-related contingent features. The Company is exposed to the credit worthiness of the institutions from which it purchases its S&P 500 Index options and these institutions continued abilities to perform according to the terms of the contracts. The current values for the credit exposure have been affected by fluctuations in the S&P 500 Index. The Company's maximum credit exposure would require an increase of approximately 4.27% in the value of the S&P 500 Index. The maximum credit risk is calculated using the cap strike price of the Company's S&P 500 Index options less the floor price, multiplied by the notional amount of the S&P 500 Index options.
	The following table sets forth the fair value of the Company's derivative assets and its maximum credit risk exposure related to its derivatives:
				31-Dec-13
				Assets at		Maximum
	(In millions)			Fair Value		Credit Risk
	Counterparty:
		The Bank of New York Mellon		$	11	$	14.3
		Goldman Sachs			4.8		5.9
			Total	$	15.8	$	20.2

Deferred_Acquisition_Costs_DAC

Deferred Acquisition Costs ("DAC"), Value Of Business Acquired ("VOBA") And Other Intangible Assets	12 Months Ended
	Dec. 31, 2013
Deferred Acquisition Costs Value Of Business Acquired And Other Intangible Assets Disclosures [Abstract]	'
Deferred Acquisition Costs ("DAC"), Value Of Business Acquired ("VOBA") And Other Intangible Assets	'
	12.        DAC, VOBA AND OTHER INTANGIBLE ASSETS
	DAC, VOBA and other acquisition related intangible assets are generally originated through the issuance of new business or the purchase of existing business, either by purchasing blocks of insurance policies from other insurers or by the outright purchase of other companies. The Company's other intangible assets consist of certain customer lists from Asset Management business acquired and an individual disability marketing agreement. See “Note 1—Summary of Significant Accounting Policies—DAC, VOBA and Other Intangible Assets” for additional information.
	The following table sets forth activity for DAC, VOBA and other intangible assets:
				Years ended
				December 31,
	(In millions)			2013			2012			2011
	Carrying value at beginning of year, net:
		DAC		$	284.9		$	274.4		$	250.1
		VOBA			23.4			26.4			28.4
		Other intangible assets			38.2			44.1			51.7
			Total balance at beginning of year		346.5			344.9			330.2
	Deferred or acquired:
		DAC			76.9			71.4			81.7
			Total deferred or acquired		76.9			71.4			81.7
	Amortized during year:
		DAC			-42.7			-60.9			-57.4
		VOBA			-3.3			-3			-2
		Other intangible assets			-6.1			-5.9			-7.6
			Total amortized during year		-52.1			-69.8			-67
	Carrying value at end of year, net:
		DAC			319.1			284.9			274.4
		VOBA			20.1			23.4			26.4
		Other intangible assets			32.1			38.2			44.1
			Total carrying value at end of year	$	371.3		$	346.5		$	344.9
	The following table sets forth the amount of DAC and VOBA balances amortized in proportion to expected gross profits and the percentage of the total balance of DAC and VOBA amortized in proportion to expected gross profits:
		31-Dec-13						31-Dec-12
	(Dollars in millions)	Amount			Percent			Amount			Percent
	DAC	$	80.1		25.1	%		$	60.9		21.4	%
	VOBA		4.3		21.4				5.9		25.2
	The value of DAC and VOBA is dependent on key assumptions. See “Note 1—Summary of Significant Accounting Policies—DAC, VOBA and Other Intangible Assets” for a discussion of the key assumptions used to determine the values of DAC and VOBA. These assumptions are modified to reflect actual experience when appropriate. Although a change in a single assumption may have an impact on the calculated amortization of DAC or VOBA for balances associated with investment contracts, it is the relationship of that change to the changes in other key assumptions that determines the ultimate impact on DAC or VOBA amortization. Because actual results and trends related to these assumptions vary from those assumed, the Company revises these assumptions annually to reflect its current best estimate of expected gross profits. As a result of this process, known as “unlocking,” the cumulative balances of DAC and VOBA are adjusted with an offsetting benefit or charge to income to reflect changes in the period of the revision. An unlocking event generally occurs as a result of actual experience or future expectations differing from previous estimates. The Company recorded a reduction to VOBA of $1.0 million in 2013 and $0.8 million in 2012 due to changes in expected gross profits related to the block of claims assumed. The Company did not record a similar impairment for 2011. As a result of unlocking, the amortization schedule for future periods is also adjusted.
	The following table sets forth the impact of unlocking on DAC and VOBA balances:
		Years ended
		December 31,
	(In millions)	2013			2012			2011
	Decrease to DAC and VOBA	$	-1.7		$	-1.7		$	-0.9
	Significant, unanticipated changes in key assumptions, which affect the determination of expected gross profits, may result in a large unlocking event that could have a material effect on the Company's financial position or results of operations. However, future changes in DAC and VOBA balances due to changes in underlying assumptions are not expected to be material.
	The accumulated amortization of VOBA was $68.7 million and $65.4 million at December 31, 2013 and 2012, respectively. The accumulated amortization of other intangible assets was $42.6 million and $36.5 million at December 31, 2013 and 2012, respectively. See “Note 1—Summary of Significant Accounting Policies—DAC, VOBA and Other Intangible Assets” for a discussion on the amortization policies for VOBA and other intangible assets.
	The following table sets forth the estimated net amortization of VOBA and other intangible assets for each of the next five years:
	(In millions)	Amount
	2014	$	7.6
	2015		7.2
	2016		5.6
	2017		4.2
	2018		4.2

Liability_For_Unpaid_Claims_Cl

Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds	12 Months Ended
	Dec. 31, 2013
Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds [Abstract]	'
Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds	'
	13.       LIABILITY FOR UNPAID CLAIMS, CLAIM ADJUSTMENT EXPENSES AND OTHER POLICYHOLDER FUNDS
	The liability for unpaid claims, claim adjustment expenses and other policyholder funds includes liabilities for insurance offered on products such as group long term and short term disability, individual disability, group dental and group vision, and group AD&D. The liability for unpaid claims and claim adjustment expenses is established when a claim is incurred or is estimated to have been incurred but not yet reported to the Company and, as prescribed by GAAP, equals the Company's best estimate of the present value of the liability of future unpaid claims and claim adjustment expenses. This liability is included in future policy benefits and claims in the consolidated balance sheets.
	The following table sets forth the change in the liability for unpaid claims and claim adjustment expenses:
				Years ended
				December 31,
	(In millions)			2013		2012		2011
	Net balance at beginning of the year:
		Balance at beginning of the year, gross of reinsurance		$	4,005.90	$	3,857.00	$	3,716.30
		Less: reinsurance recoverable			-128.6		-117.3		-110.5
			Net balance at beginning of the year		3,877.30		3,739.70		3,605.80
	Incurred related to:
		Current year			1,081.70		1,140.30		1,077.10
		Prior year's interest			180.3		181.2		175.9
		Prior years			-133.2		-79.8		-46.5
			Total incurred		1,128.80		1,241.70		1,206.50
	Paid related to:
		Current year			-345.9		-354.8		-347.1
		Prior year			-778.2		-749.3		-725.5
			Total paid		-1,124.10		-1,104.10		-1,072.60
	Net balance at end of the year				3,882.00		3,877.30		3,739.70
		Plus: reinsurance recoverable			139.9		128.6		117.3
			Balance at end of the year, gross of reinsurance	$	4,021.90	$	4,005.90	$	3,857.00
	Classified as future policy benefits and claims, but excluded from the table above are amounts recorded for group and individual life reserves, group and individual annuity reserves, and individual disability active life reserves.
	The following table sets forth the reconciliation of amounts above to future policy benefits and claims as presented on the consolidated balance sheets:
				Years ended
				December 31,
	(In millions)			2013		2012		2011
	Future policy benefits and claims			$	5,846.90	$	5,843.20	$	5,683.60
		Less: Group life reserves			-751.7		-765.3		-765.4
		Less: Individual life reserves			-603.6		-600.9		-597.2
		Less: Group and individual annuity reserves			-220		-237.4		-244.2
		Less: Individual disability active life reserves			-249.7		-233.7		-219.8
			Liability for unpaid claims and claim adjustment expenses	$	4,021.90	$	4,005.90	$	3,857.00
	The majority of the net liability balances are related to long term disability claims on which interest earned on assets backing the reserves is a key component of reserving and pricing. The year-to-year development of incurred claims related to prior years is therefore broken out into an interest portion and remaining incurred portion.
	The changes in amounts incurred related to prior years are not the result of a significant change in an underlying assumption or method used to determine the estimate. Instead the Company expects these amounts to change over time as a result of the growth in the size of the Company's in force insurance business and the actual claims experience with respect to that business during the time periods captured for claims with an incurred date in years prior to the year of valuation. Interest is also a key component in the year-to-year development of the reserves and therefore the positive changes in amounts incurred related to prior years should not be taken as an indicator of the adequacy or inadequacy of the reserves held. In each of the years captured, there was a decrease in incurred amounts associated with prior years after the effect of interest is taken into account, indicating that claim experience was favorable compared to the assumptions used to establish the associated reserves. Significant changes to assumptions regarding unpaid claims and claims adjustment expenses for prior periods in the group long term disability reserves were not made in 2013, 2012 and 2011 primarily due to the long-term nature of this product and the materiality of other factors including the potential impact of the economic uncertainty in 2013, 2012 and 2011. The Company carefully monitors trends in reserve assumptions and when these trends become credible and are expected to persist, the Company incorporates these factors into its reserves to ensure best estimates are established.
	The following table sets forth the composition of other policyholder funds:
				Years ended
				December 31,
	(In millions)			2013		2012
	Retirement plan stable asset funds			$	1,954.10	$	1,554.10
	Individual fixed-rate annuity funds				2,541.70		2,434.90
	Indexed annuity funds				440.8		409.2
	Investment only stable asset funds				326.1		336.4
	Other				788.9		796.5
		Total other policyholder funds		$	6,051.60	$	5,531.10
	The primary components of other policyholder funds are retirement plan stable asset funds which the Company provides recordkeeping services, individual fixed-rate annuity funds, indexed annuity funds and investment only stable asset funds. The remaining balance is comprised primarily of premiums on deposits, advanced premiums and experience related liabilities.

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2013
Reinsurance [Abstract]	'
Reinsurance	'
	14. REINSURANCE
	In order to limit its losses from large claim exposures, the Company enters into reinsurance agreements with other insurance companies. The Company reviews its retention limits based on size and experience. The maximum retention limit per individual for group life and AD&D is $750,000. The Company's maximum retention limit per individual for group disability insurance is $15,000 of monthly benefit. The Company's maximum retention limit per individual for individual disability insurance is $6,000 of monthly benefit.
	Standard maintains a strategic marketing alliance with Ameritas Life Insurance Corp. (“Ameritas”) that offers Standard's policyholders more flexible dental coverage options and access to Ameritas' nationwide preferred provider organization panel of dentists. As part of this alliance, Standard and Ameritas entered into a reinsurance agreement. In 2013, the agreement provided for 26.1% of the net dental premiums written by Standard and the risk associated with this premium to be ceded to Ameritas.
	Standard participates in a reinsurance and third-party administration arrangement with Northwestern Mutual Life Insurance Company (“Northwestern Mutual”) under which Northwestern Mutual group long term and short term disability products are sold using Northwestern Mutual's agency distribution system. Generally, Standard assumes 60% of the risk and receives 60% of the premiums for the policies issued. If Standard were to become unable to meet its obligations, Northwestern Mutual would retain the reinsured liabilities. Therefore, in accordance with an agreement with Northwestern Mutual, Standard established a trust for the benefit of Northwestern Mutual with the market value of assets in the trust equal to Northwestern Mutual's reinsurance receivable from Standard. The market value of assets required to be maintained in the trust at December 31, 2013, was $233.6 million. Premiums assumed by Standard for the Northwestern Mutual business accounted for approximately 3% of the Standard's total premiums for each of the three years 2013, 2012 and 2011. In addition to assuming risk, Standard provides product design, pricing, underwriting, legal support, claims management and other administrative services under the arrangement.
	In 2012, the Company amended its Yearly Renewable Term reinsurance agreement with Canada Life Assurance Company (“Canada Life”). The amendment increased the amount of group life insurance risk to be ceded to Canada Life. The amended agreement limits the Standard's exposure to losses in the event of a catastrophe impacting its group life business. This amendment to Standard's reinsurance agreement released approximately $100 million of additional net capital, for a total release of approximately $170 million. This release of capital can fluctuate based on a percentage of Standard's in-force business. The agreement is subject to termination by either party.
	The Company also maintains reinsurance coverage for certain catastrophe losses related to group life and AD&D with partial coverage of nuclear, biological and chemical acts of terrorism. Through a combination of this agreement and its participation in a catastrophe reinsurance pool discussed below, the Company has coverage of up to $520.0 million per event.
	The Company is part of a catastrophe reinsurance pool with other insurance companies. This pool spreads catastrophe losses from group life and AD&D over 21 participating members. The annual fee paid by the Company in 2013 to participate in the pool was less than $30,000. As a member of the pool, the Company is exposed to maximum potential losses experienced by other participating members of up to $112.6 million for a single event for losses submitted by a single company and a maximum of $281.8 million for a single event for losses submitted by multiple companies. The Company's percentage share of losses experienced by pool members will change over time as it is a function of the Company's group life and AD&D in force relative to the total group life and AD&D in force for all pool participants. The catastrophe reinsurance pool does not exclude war or nuclear, biological and chemical acts of terrorism.
	The Terrorism Risk Insurance Act of 2002 (“TRIA”), which has been extended through 2014, provides for federal government assistance to property and casualty insurers in the event of material losses due to terrorist acts on behalf of a foreign person or foreign interest. Due to the concentration of risk present in group life insurance and the fact that group life insurance is not covered under TRIA, an occurrence of a significant catastrophe or a change in the on-going nature and availability of reinsurance and catastrophe reinsurance could have a material adverse effect on the Company.
	The following table sets forth reinsurance information:
								Assumed				Percentage of
						Ceded to		From				Amount
						Other		Other				Assumed
	(Dollars in millions)			Gross Amount		Companies		Companies		Net Amount		to Net
	2013:00:00
	Life insurance in force			$	321,881.70	$	5,966.80	$	57.7	$	315,972.60	0	%
	Premiums:
		Life insurance and annuities		$	898.5	$	48.5	$	0	$	850	0
		Accident and health insurance			1,258.60		81		96.7		1,274.30	7.6
			Total premiums	$	2,157.10	$	129.5	$	96.7	$	2,124.30	4.6
	2012:00:00
	Life insurance in force			$	346,814.50	$	7,233.10	$	65.1	$	339,646.50	0	%
	Premiums:
		Life insurance and annuities		$	937.9	$	51	$	0	$	886.9	0
		Accident and health insurance			1,263.30		83.7		97.4		1,277.00	7.6
			Total premiums	$	2,201.20	$	134.7	$	97.4	$	2,163.90	4.5
	2011:00:00
	Life insurance in force			$	350,623.10	$	55,126.00	$	71.7	$	295,568.80	0	%
	Premiums:
		Life insurance and annuities		$	942.3	$	52.2	$	0	$	890.1	0
		Accident and health insurance			1,241.80		76.1		97.5		1,263.20	7.7
			Total premiums	$	2,184.10	$	128.3	$	97.5	$	2,153.30	4.5
	Recoveries recognized under reinsurance agreements were $79.8 million, $74.0 million and $75.9 million for 2013, 2012 and 2011, respectively. Amounts recoverable from reinsurers were $988.1 million and $972.4 million at December 31, 2013 and 2012, respectively. Of these amounts, $791.0 million and $793.0 million for 2013 and 2012, respectively, were from the reinsurance transaction with Protective Life Insurance Company (“Protective Life”) effective January 1, 2001. See “Note 15—Reinsurance of Blocks of Business.”

Reinsurance_Of_Blocks_Of_Busin

Reinsurance Of Blocks Of Business	12 Months Ended
	Dec. 31, 2013
Reinsurance Of Blocks Of Business [Abstract]	'
Reinsurance Of Blocks Of Business	'
	15.       REINSURANCE OF BLOCKS OF BUSINESS
	Effective October 1, 2000, Standard assumed, through a reinsurance agreement, the individual disability insurance business of Minnesota Life. Standard paid a ceding commission of approximately $55 million and received approximately $500 million in assets and corresponding statutory liabilities. If Standard were to become unable to meet its obligations, Minnesota Life would retain the reinsured liabilities. Therefore, in accordance with the agreement with Minnesota Life, Standard established a trust for the benefit of Minnesota Life with the market value of assets in the trust equal to Minnesota Life's reinsurance receivable from Standard. The market value of assets required to be maintained in the trust is determined quarterly. The market value of assets required to be maintained in the trust at December 31, 2013, was $569.2 million. Accompanying the transaction was a national marketing agreement that provides access to Minnesota Life agents, some of whom now market Standard's individual disability insurance products. The national marketing agreement is renewed annually.
	Effective January 1, 2001, Standard ceded to Protective Life, through a reinsurance agreement, Standard's individual life insurance product line. Standard received a ceding commission of approximately $90 million and transferred to Protective Life approximately $790 million in assets and corresponding statutory liabilities. If Protective Life were to become unable to meet its obligations, Standard would retain the reinsured liabilities. Therefore, the liabilities remain on Standard's consolidated balance sheets, and an equal amount is recorded as a recoverable from the reinsurer. In accordance with the agreement, Protective Life established a trust for the benefit of Standard with assets in the trust required to be equal to Standard's reinsurance receivable from Protective Life. The Company evaluates the collectability of the amounts recoverable from reinsurers by monitoring the value of assets held in trust and other factors, such as claims activity and timing of payments made on claims. The amount of assets required to be maintained in the trust is determined quarterly.
	Effective October 1, 2002, Standard entered into a reinsurance agreement with TIAA to assume TIAA's group disability and group life insurance business. This business included approximately 1,800 group insurance contracts, representing 650,000 insured individuals. Standard paid a ceding commission of approximately $75 million and received approximately $705 million in assets and corresponding statutory liabilities. If Standard were to become unable to meet its obligations, TIAA would retain the reinsured liabilities. Therefore, in accordance with the agreement with TIAA, Standard established a trust for the benefit of TIAA with the market value of assets in the trust equal to TIAA's reinsurance receivable from Standard. The market value of assets required to be maintained in the trust is determined quarterly. The market value of assets required to be maintained in the trust at December 31, 2013, was $215.1 million. Approximately $60.0 million in VOBA was recorded related to the reinsurance agreement.

Insurance_Information

Insurance Information	12 Months Ended
	Dec. 31, 2013
Insurance Information [Abstract]	'
Insurance Information	'
	16.       INSURANCE INFORMATION
	The following table sets forth insurance information:
						Future								Benefits,
						Policy		Other				Net		Claims and		Amortization		Other
						Benefits		Policyholder		Premium		Investment		Interest		of		Operating
	(In millions)			DAC, net(1)		and Claims		Funds		Revenues		Income		Credited		DAC		Expenses (2)
	2013:00:00
	Employee Benefits			$	24.2	$	3,995.90	$	315.3	$	1,926.90	$	267.8	$	1,520.20	$	22.6	$	473.2
	Individual Disability				214.8		1,631.10		198.9		190.5		52.8		121.8		22.6		65.7
		Total Insurance
			Services		239		5,627.00		514.2		2,117.40		320.6		1,642.00		45.2		538.9
		Asset Management			80.1		219.9		5,537.40		6.9		293.2		189.8		17.7		155.9
			Total	$	319.1	$	5,846.90	$	6,051.60	$	2,124.30	$	613.8	$	1,831.80	$	62.9	$	694.8
	2012:00:00
	Employee Benefits			$	24.6	$	4,025.60	$	353.5	$	1,980.60	$	286	$	1,661.30	$	23.9	$	489.2
	Individual Disability				199.3		1,580.20		203.5		176.6		53.7		116.2		21.9		64.3
		Total Insurance
			Services		223.9		5,605.80		557		2,157.20		339.7		1,777.50		45.8		553.5
		Asset Management			61		237.4		4,974.10		6.7		278.6		186.8		15.8		153.3
			Total	$	284.9	$	5,843.20	$	5,531.10	$	2,163.90	$	618.3	$	1,964.30	$	61.6	$	706.8
	2011:00:00
	Employee Benefits			$	30.1	$	3,910.00	$	376.9	$	1,973.00	$	288.6	$	1,639.60	$	22.8	$	478.1
	Individual Disability				183.6		1,529.40		202.4		172.3		52.7		115.9		20.1		64.1
		Total Insurance
			Services		213.7		5,439.40		579.3		2,145.30		341.3		1,755.50		42.9		542.2
		Asset Management			60.7		244.2		4,498.80		8		262.7		176.7		16.2		152.6
			Total	$	274.4	$	5,683.60	$	5,078.10	$	2,153.30	$	604	$	1,932.20	$	59.1	$	694.8
	(1)       See “Note 1—Summary of Significant Accounting Policies—DAC, VOBA and Other Intangible Assets” And “Note 12—DAC, VOBA and Other Intangible Assets.”
	(2)       Other operating expenses include operating expenses, commissions and bonuses, premium taxes, interest expense and the net increase in DAC, VOBA and other intangible assets.

Regulatory_Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2013
Regulatory Matters [Abstract]	'
Regulatory Matters	'
	17. REGULATORY MATTERS
	Standard and The Standard Life Insurance Company of New York prepare their statutory financial statements in accordance with accounting practices prescribed or permitted by their states of domicile. Prescribed statutory accounting practices include state laws, regulations, and general administrative rules, as well as the Statements of Statutory Accounting Principles (“SSAP”) set forth in publications of the National Association of Insurance Commissioners (“NAIC”). Standard and the Standard Life Insurance Company of New York did not use any prescribed or permitted statutory accounting practices that are different than the statutory accounting practices promulgated by the NAIC for the years ended 2013, 2012 or 2011.
	Statutory accounting practices differ in some respects from GAAP. The principal statutory accounting practices that differ from GAAP are:
	Bonds and commercial mortgage loans are reported principally at amortized cost and adjusted carrying value, respectively.
	Asset valuation and the interest maintenance reserves are provided as prescribed by the NAIC.
	Certain assets designated as non-admitted, principally deferred tax assets, furniture, equipment, and unsecured receivables are not recognized as assets, resulting in a charge to statutory surplus.
	Annuity considerations with life contingencies, or purchase rate guarantees, are recognized as revenue when received.
	Reserves for life and disability policies and contracts are reported net of ceded reinsurance and calculated based on statutory requirements, including required discount rates.
	Commissions, including initial commissions and expense allowance paid for reinsurance assumed, and other policy acquisition expenses are expensed as incurred.
	Initial commissions and expense allowance received for a block of reinsurance ceded net of taxes are reported as deferred gains in surplus and recognized as income in subsequent periods.
	Federal income tax expense includes current income taxes defined as current year estimates of federal income taxes and tax contingencies for current and all prior years and amounts incurred or received during the year relating to prior periods, to the extent not previously provided.
	Deferred tax assets, net of deferred tax liabilities, which will be realized within three years, are considered admitted assets and are included in the regulatory financial statements.
	Surplus notes are classified as a component of surplus for statutory reporting and are classified as a liability for GAAP reporting.
	Standard and The Standard Life Insurance Company of New York are subject to statutory restrictions that limit the maximum amount of dividends and distributions that they could declare and pay to StanCorp without prior approval of the states in which the subsidiaries are domiciled. Standard's ability to pay dividends to StanCorp is affected by factors deemed relevant by Standard's Board of Directors and by Oregon law, which limits Standard's dividend payments and other distributions to the earned surplus arising from its business. If the proposed dividend or other distribution exceeds certain statutory limitations, Standard must receive prior approval of the Director of the Oregon Department of Consumer and Business Services—Insurance Division (“Oregon Insurance Division”). The current statutory dividend limitations are the greater of (a) 10% of Standard's combined capital and surplus as of December 31 of the preceding year, or (b) the net gain from operations after dividends to policyholders and federal income taxes and before realized capital gains or losses for the 12-month period ended on the preceding December 31. In each case, the limitation must be determined under statutory accounting practices. Oregon law gives the Oregon Insurance Division broad discretion to approve or decline requests for dividends and other distributions in excess of these limits. As of December 31, 2013, Standard's net gain from operations after dividends to policyholders and federal income taxes and before capital gains or losses for the 12-month period then ended was $195.1 million and capital and surplus was $1.29 billion. Based upon Standard's results for 2013, the amount of ordinary dividends and other distributions available in 2014, without additional approval from the Oregon Insurance Division is $195.1 million. As of December 31, 2012, Standard's net gain from operations after dividends to policyholders and federal income taxes and before capital gains or losses for the 12-month period then ended was $132.7 million and capital and surplus was $1.19 billion. Based upon Standard's results for 2012, the amount of ordinary dividends and other distributions available in 2013, without additional approval from the Oregon Insurance Division was $132.7 million.
	During 2013 and 2012, Standard made distributions to StanCorp totaling $130.0 million and $320.0 million, respectively.
	During 2012, StanCorp made a capital infusion of $10.0 million to The Standard Life Insurance Company of New York. In 2013, there was not a capital infusion between StanCorp and The Standard Life Insurance Company of New York.
	State insurance departments require insurance enterprises to adhere to minimum Risk-based Capital (“RBC”) requirements promulgated by the NAIC. At December 31, 2013 and 2012, the insurance subsidiaries' capital levels were significantly in excess of that which would require corrective action by the insurance subsidiaries or regulatory agencies. The Authorized Control Level RBC was $186.6 million and $189.1 million at December 31, 2013 and 2012, respectively. At December 31, 2013, the capital of the Company's insurance subsidiaries was approximately 398% of the Company Action Level RBC required by regulators, which was approximately 796% of the Authorized Control Level RBC required by the Company's states of domicile. At December 31, 2012, the capital of the Company's insurance subsidiaries was approximately 365% of the Company Action Level RBC required by regulators, which was approximately 730% of the Authorized Control Level RBC required by the Company's states of domicile.
	The following table reconciles the statutory capital and surplus of the insurance subsidiaries based on statutory filings with applicable insurance regulatory authorities to the Company's GAAP equity:
			December 31,
	(In millions)		2013		2012
	Statutory capital and surplus		$	1,359.00	$	1,259.60
	Adjustments to reconcile to GAAP equity:
		Future policy benefits and other policyholder funds		325.8		301.7
		DAC, VOBA and other intangible assets		351.6		322
		Deferred tax liabilities		-265.3		-236.8
		Asset valuation reserve		127.5		117.5
		Valuation of investments		236.4		449.8
		Interest maintenance reserve		25.5		24.8
		Equity of StanCorp and its non-insurance subsidiaries		116.1		51.6
		Non-admitted assets		178.2		144.1
		Pension and postretirement benefit plans		-6.6		3.6
		Capital lease obligations		-3.4		-2.4
		Surplus note		-250		-250
		Other, net		-42		-16.5
	GAAP equity		$	2,152.80	$	2,169.00
	The following table reconciles statutory net income based on statutory filings with applicable insurance regulatory authorities to the Company's GAAP net income:
			Years ended December 31,
	(In millions)		2013		2012		2011
	Statutory net income		$	198.5	$	131.5	$	125.8
	Adjustments to reconcile to GAAP net income:
		Future policy benefits and other policyholder funds		11		26.4		48
		DAC and VOBA, net of amortization		9.4		5.5		19.2
		Deferred income taxes		-13.5		-22.4		-42.1
		Current income taxes		9.6		17.2		24.7
		Earnings of StanCorp and its non-insurance subsidiaries		-8.9		-23.8		-18.9
		Deferred capital gains (interest maintenance reserve)		0.7		5		7.2
		Pension and postretirement benefit plans		17.6		-1.7		-3.1
		Share based compensation		-3.6		-5.4		-5.2
		Investments		8.5		5.8		-12.6
		Other, net		-0.8		0.4		-6.3
	GAAP net income		$	228.5	$	138.5	$	136.7

LongTerm_Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2013
Long-Term Debt [Abstract]	'
Long-Term Debt	'
	18.       LONG-TERM DEBT
	On August 10, 2012, the Company issued $250 million of 5.00%, 10-year senior notes (“2022 Senior Notes''), which mature on August 15, 2022. Interest is payable semi-annually on February 15 and August 15. The Company used the net proceeds from the issuance of the 2022 Senior Notes to repay the $250 million of 6.875%, 10-year senior notes (“2012 Senior Notes”), on September 28, 2012.
	The Company has $300 million of 6.90%, junior subordinated debentures (“Subordinated Debt”), which matures on June 1, 2067 and is non-callable for the first 10 years (prior to June 1, 2017). The principal amount of the Subordinated Debt is payable at final maturity. Interest is payable semi-annually on June 1 and December 1 for the first 10 years up to June 1, 2017, and quarterly thereafter at a floating rate equal to three-month LIBOR plus 2.51%. StanCorp has the option to defer interest payments for up to five years. The declaration and payment of dividends to shareholders would be restricted if the Company elected to defer interest payments on its Subordinated Debt. If elected, the restriction would be in place during the interest deferral period. StanCorp is currently not deferring interest on the Subordinated Debt.
	The following table sets forth the Company's long-term debt:
				December 31,
	(In millions)			2013		2012
	Long-term debt:
		Senior notes		$	250	$	250
		Subordinated debt			300		300
		Other long-term borrowings			1.9		1.4
			Total long-term debt	$	551.9	$	551.4

Commitments_And_Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2013
Commitments And Contingencies [Abstract]	'
Commitments And Contingencies	'
	19. COMMITMENTS AND CONTINGENCIES
	Litigation Contingencies
	In the normal course of business, the Company is involved in various legal actions and other state and federal proceedings. A number of actions or proceedings were pending at December 31, 2013. In some instances, lawsuits include claims for punitive damages and similar types of relief in unspecified or substantial amounts, in addition to amounts for alleged contractual liability or other compensatory damages. In the opinion of management, the ultimate liability, if any, arising from the actions or proceedings is not expected to have a material effect on the Company's business, financial position, results of operations or cash flows.
	Senior Unsecured Revolving Credit Facility (“Facility”) Contingencies
	The Company maintains a $250 million Facility. Upon the request of StanCorp and with the consent of the lenders under the Facility, the Facility can be increased to $350 million. The termination date of the Facility is June 22, 2017, though, at the option of StanCorp and with the consent of the lenders under the Facility, the termination date can be extended one additional year to June 22, 2018. The Company expects to use the Facility for working capital, general corporate purposes and for the issuance of letters of credit.
	Under the agreement, the Company is subject to two financial covenants that are based on the Company's ratio of total debt to total capitalization and consolidated net worth. The Company is also subject to covenants that limit subsidiary indebtedness. The Facility is subject to pricing levels based upon the Company's publicly announced debt ratings and includes an interest rate option at the election of the borrower of a base rate plus the applicable margin or LIBOR plus the applicable margin, plus facility and utilization fees. At December 31, 2013, the Company was in compliance with all financial covenants under the Facility and had no outstanding balance on the Facility.
	Operating Lease Commitments
	The Company leases certain buildings and equipment under non-cancelable operating leases that expire in various years through 2023. Most of these leases have renewal options for periods ranging from one to ten years.
	The following table sets forth future minimum payments under the leases:
	(In millions)
	2014	$	8.9
	2015		7.9
	2016		7.6
	2017		7.1
	2018		2.6
	Thereafter		1.8
	Total rent expense was $13.7 million, $15.2 million and $16.4 million for the years ended December 31, 2013, 2012 and 2011, respectively.
	The following table sets forth the minimum future rental receivables on non-cancelable leases of retail and office space with initial terms of one year or more:
	(In millions)
	2014	$	7.4
	2015		6.6
	2016		4.7
	2017		2.1
	2018		1.5
	Thereafter		5.9
	Other Financing Obligations
	The Company's financing obligations include long-term debt and capital lease payment obligations as well as commitments to fund commercial mortgage loans.
	The Company's debt obligations consisted primarily of the $250 million 5.00% 2022 Senior Notes and the $300 million 6.90% Subordinated Debt. See “Note 18—Long-Term Debt” for additional information.
	In the normal course of business, the Company commits to fund commercial mortgage loans generally up to 90 days in advance. At December 31, 2013, the Company had outstanding commitments to fund commercial mortgage loans totaling $197.6 million, with fixed interest rates ranging from 4.25% to 5.75%. These commitments generally have fixed expiration dates. A small percentage of commitments expire due to the borrower's failure to deliver the requirements of the commitment by the expiration date. In these cases, the Company will retain the commitment fee and good faith deposit. Alternatively, if the Company terminates a commitment due to the disapproval of a commitment requirement, the commitment fee and good faith deposit may be refunded to the borrower, less an administrative fee.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2013
AOCI, net of tax [Abstract]	'
Accumulated Other Comprehensive Income [Text Block]	'
	20.       ACCUMULATED OTHER COMPREHENSIVE INCOME
	The following table sets forth the changes in accumulated other comprehensive income (loss) by component:
				Net Unrealized				Total
				Gains (Losses) on				Accumulated
				Fixed Maturity		Employee		Other
				Securities		Benefit		Comprehensive
	(In millions)			Available-for-Sale		Plans		Income (Loss)
	Balance, January 1, 2012			$	315.2	$	-80.1	$	235.1
		Other comprehensive income, net of tax
			before reclassification adjustment(1)		71.4		0		71.4
		Amounts reclassified from accumulated
			other comprehensive income, net of tax(2)		-3.6		6.4		2.8
	Net other comprehensive income, net of tax				67.8		6.4		74.2
	Balance, December 31, 2012				383		-73.7		309.3
		Other comprehensive (loss) income, net of tax
			before reclassification adjustment(3)		-205.3		41.2		-164.1
		Amounts reclassified from accumulated
			other comprehensive income, net of tax(4)		-4.5		-6		-10.5
	Net other comprehensive (loss) income, net of tax				-209.8		35.2		-174.6
	Balance, December 31, 2013			$	173.2	$	-38.5	$	134.7
	Net of tax expense of $38.3 million for unrealized gains on fixed maturity securities and $0.2 million for employee benefits, respectively.
	Net of tax benefit of $2.2 million for unrealized gains on fixed maturity securities and net of tax expense of $3.4 million for employee benefits.
	Net of tax benefit of $111.1 million for unrealized losses on fixed maturity securities and net of tax expense of $22.2 million for employee benefits.
	Net of tax benefit of $3.1 million for unrealized gains on fixed maturity securities and $3.2 million for employee benefits, respectively.

Severance_Lease_Terminations_A

Severance, Lease Terminations And Transition Costs	12 Months Ended
	Dec. 31, 2013
Severance, Lease Terminations, And Transition Costs [Abstract]	'
Severance, Lease Terminations, And Transition Costs	'
	21.       SEVERANCE, TRANSITION COSTS AND LEASE TERMINATIONS
	During 2013, the Company implemented expense management initiatives to offset the negative effects of the continued low interest rate environment and lower Employee Benefits premiums compared to 2012. In addition to severance, transition costs and lease terminations, the Company incurred $2.3 million in other project initiatives.
	The following tables set forth expenses incurred related to the expense management initiatives:
			Years ended December 31, 2013
			Beginning						Ending
			Accrued		Charged to				Accrued
	(In millions)		Liability(1)		Expense, Net		Expenditures		Liability
	Severance		$	0.1	$	2.9	$	2.8	$	0.2
	Transition costs			0		1.3		1.3		0
	Lease terminations			0.3		0		0.3		0
		Total severance, transition costs and lease terminations	$	0.4	$	4.2	$	4.4	$	0.2
			Year Ended December 31, 2012
			Beginning						Ending
			Accrued		Charged to				Accrued
	(In millions)		Liability(1)		Expense, Net		Expenditures		Liability
	Severance		$	1	$	0	$	0.9	$	0.1
	Transition costs			0		0		0		0
	Lease terminations			1		0		0.7		0.3
		Total severance, transition costs and lease terminations	$	2	$	0	$	1.6	$	0.4
	Amounts relate to restructuring charges implemented by the Company during 2011.

Quarterly_Financial_Informatio

Quarterly Financial Information	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information [Abstract]	'
Quarterly Financial Information	'
	SUPPLEMENTARY DATA
	Quarterly Financial Information (Unaudited)
	The following tables set forth select unaudited financial information by calendar quarter:
			2013
	(In millions—except per share data)		4th Quarter		3rd Quarter		2nd Quarter		1st Quarter
	Premiums		$	528.6	$	524.4	$	535.1	$	536.2
	Administrative fees			32		30.5		30.4		28.7
	Net investment income			160.8		155.8		154.1		159.2
	Net capital losses			-2.8		-8.7		-2.6		-1.6
		Total revenues		718.6		702		717		722.5
	Benefits to policyholders			394.5		395		424.1		441.8
	Net income			65		59		57.7		46.8
	Net income per common share:
		Basic	$	1.48	$	1.33	$	1.3	$	1.05
		Diluted		1.46		1.32		1.3		1.05
			2012
	(In millions—except per share data)		4th Quarter		3rd Quarter		2nd Quarter		1st Quarter
	Premiums		$	533.8	$	528.7	$	548.1	$	553.3
	Administrative fees			28.5		27.8		29.8		28.6
	Net investment income			157.6		159.8		151.4		159.7
	Net capital losses			-1.9		-2.6		-4		-0.2
		Total revenues		718		713.7		725.3		741.4
	Benefits to policyholders			444.7		422.4		475.9		450
	Net income			38.4		44.9		20		35.2
	Net income per common share:
		Basic	$	0.87	$	1.02	$	0.45	$	0.79
		Diluted		0.87		1.01		0.45		0.79

Summary_Of_Significant_Account1

Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]	'
Organization, Principles Of Consolidation, And Basis Of Presentation	'
	1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Organization, principles of consolidation, and basis of presentation
	StanCorp, headquartered in Portland, Oregon, is a holding company and conducts business through wholly-owned operating subsidiaries throughout the United States. Through its subsidiaries, StanCorp has the authority to underwrite insurance products in all 50 states. The Company collectively views and operates its businesses as Insurance Services and Asset Management, which both deliver distinct value to customers and shareholders. Insurance Services contains two reportable product segments, Employee Benefits and Individual Disability. See “Note 5—Segments.”
	StanCorp has the following wholly-owned operating subsidiaries: Standard Insurance Company (“Standard”), The Standard Life Insurance Company of New York, Standard Retirement Services, Inc. (“Standard Retirement Services”), StanCorp Equities, Inc. (“StanCorp Equities”), StanCorp Mortgage Investors, LLC (“StanCorp Mortgage Investors”), StanCorp Investment Advisers, Inc. (“StanCorp Investment Advisers”), StanCorp Real Estate, LLC (“StanCorp Real Estate”) and Standard Management, Inc. (“Standard Management”).
	Standard, the Company's largest subsidiary, underwrites group and individual disability insurance and annuity products, group life and accidental death and dismemberment (“AD&D”) insurance, and provides group dental and group vision insurance, absence management services and retirement plan products. Founded in 1906, Standard is domiciled in Oregon, licensed in all states except New York, and licensed in the District of Columbia and the U.S. territories of Guam and the Virgin Islands.
	The Standard Life Insurance Company of New York was organized in 2000 and is licensed to provide group long term and short term disability insurance, group life and AD&D insurance, group dental insurance and individual disability insurance in New York.
	The Standard is a service mark of StanCorp and its subsidiaries and is used as a brand mark and marketing name by Standard and The Standard Life Insurance Company of New York.
	Standard Retirement Services administers and services StanCorp's retirement plans group annuity contracts and trust products. Retirement plan products are offered in all 50 states through Standard or Standard Retirement Services.
	StanCorp Equities is a limited broker-dealer and member of the Financial Industry Regulatory Authority. As a wholesaler, StanCorp Equities activities are limited to soliciting and supporting third-party broker-dealers and investment advisers that offer or advise their retirement plan clients on using an unregistered group annuity contract or a mutual fund trust platform.
	StanCorp Mortgage Investors originates and services fixed-rate commercial mortgage loans for the investment portfolios of the Company's insurance subsidiaries. StanCorp Mortgage Investors also generates additional fee income from the origination and servicing of commercial mortgage loans participated to institutional investors.
	StanCorp Investment Advisers is a Securities and Exchange Commission (“SEC”) registered investment adviser providing performance analysis, fund selection support, model portfolios and other investment advisory, financial planning, and investment management services to its retirement plan clients, individual investors and subsidiaries of StanCorp.
	StanCorp Real Estate is a property management company that owns and manages the Hillsboro, Oregon home office properties and other properties held for investment and held for sale. StanCorp Real Estate also manages the Portland, Oregon home office properties.
	Standard Management manages certain real estate properties held for sale from time-to-time in conjunction with our real estate business.
	Standard holds interests in tax-advantaged investments. These interests do not meet the requirements for consolidation under existing accounting standards, and thus the Company's interests in the tax-advantaged investments are accounted for under the equity method of accounting. The total investment in these interests was $192.4 million and $173.0 million at December 31, 2013 and 2012 respectively.
	The consolidated financial statements include StanCorp and its subsidiaries. Intercompany balances and transactions have been eliminated on a consolidated basis.
Use Of Estimates	'
	Use of estimates
	The Company's consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) which require management to make estimates and assumptions that affect reported amounts of assets and liabilities and disclosures of contingent assets and contingent liabilities at the dates of the financial statements and the reported amounts of revenues and expenses during the reporting periods. The estimates most susceptible to material changes due to significant judgment are those used in determining investment valuations, deferred acquisition costs (“DAC”), value of business acquired (“VOBA”) and other intangible assets, the reserves for future policy benefits and claims, pension and postretirement benefit plans and the provision for income taxes. The results of these estimates are critical because they affect the Company's profitability and may affect key indicators used to measure the Company's performance. These estimates have a material effect on our results of operations and financial condition.
Investment Valuations Fixed Maturity Securities-Available-For-Sale ("Fixed Maturity Securities")	'
	Investment Valuations
	Fixed Maturity Securities—Available-for-sale (“Fixed Maturity Securities”)
	Fixed maturity security capital gains and losses are recognized using the specific identification method. If a debt security's fair value declines below its amortized cost, the Company must assess the security's impairment to determine if the impairment is other than temporary.
	In the Company's quarterly fixed maturity security impairment analysis, management evaluates whether a decline in value of the fixed maturity security is other than temporary by considering the following factors:
	The nature of the fixed maturity security.
	The duration until maturity.
	The duration and extent the fair value has been below amortized cost.
	The financial quality of the issuer.
	Estimates regarding the issuer's ability to make the scheduled payments associated with the fixed maturity security.
	The Company's intent to sell or whether it is more likely than not we will be required to sell a fixed maturity security before recovery of the security's cost basis through the evaluation of facts and circumstances including, but not limited to, decisions to rebalance our portfolio, current cash flow needs and sales of securities to capitalize on favorable pricing.
	If it is determined an other-than-temporary impairment (“OTTI”) exists, we separate the OTTI of debt securities into an OTTI related to credit loss and an OTTI related to noncredit loss. The OTTI related to credit loss represents the portion of losses equal to the difference between the present value of expected cash flows, discounted using the pre-impairment yields, and the amortized cost basis. All other changes in value represent the OTTI related to noncredit loss. The OTTI related to credit loss is recognized in earnings in the current period, while the OTTI related to noncredit loss is deemed recoverable and is recognized in other comprehensive income. The cost basis of the fixed maturity security is permanently adjusted to reflect the credit related impairment. Once an impairment charge has been recorded, the Company continues to review the OTTI securities for further potential impairment.
	The Company will continue to evaluate our holdings; however, the Company currently expects the fair values of our investments to recover either prior to their maturity dates or upon maturity. Should the credit quality of the Company's fixed maturity securities significantly decline, there could be a material adverse effect on the Company's business, financial position, results of operations or cash flows.
	In conjunction with determining the extent of credit losses associated with debt securities, the Company utilizes certain information in order to determine the present value of expected cash flows discounted using pre-impairment yields. Some of these input factors include, but are not limited to, original scheduled contractual cash flows, current market spread information, risk-free rates, fundamentals of the industry and sector in which the issuer operates, and general market information.
	Fixed maturity securities are classified as available-for-sale and are carried at fair value on the consolidated balance sheet. See “Note 9—Fair Value” for a detailed explanation of the valuation methods the Company uses to calculate the fair value of the Company's financial instruments. Valuation adjustments for fixed maturity securities not accounted for as OTTI are reported as net increases or decreases to other comprehensive income (loss), net of tax, on the consolidated statements of comprehensive income.
Commercial Mortgage Loans	'
	Commercial Mortgage Loans
	Commercial mortgage loans are stated at amortized cost less a loan loss allowance for probable uncollectible amounts. The commercial mortgage loan loss allowance is estimated based on evaluating known and inherent risks in the loan portfolio and consists of a general and a specific loan loss allowance.
	Impairment Evaluation
	The Company continuously monitors its commercial mortgage loan portfolio for potential impairment by evaluating the portfolio and individual loans. Key factors that are monitored are as follows:
	Loan loss experience.
	Delinquency history.
	Debt coverage ratio.
	Loan to value ratio.
	Refinancing and restructuring history.
	Request for forbearance history.
	If the analysis above indicates a loan might be impaired, it is further analyzed through the consideration of the following additional factors:
	Delinquency status.
	Foreclosure status.
	Restructuring status.
	Borrower history.
	If it is determined a loan is impaired, a specific allowance is recorded.
	General Loan Loss Allowance
	The general loan loss allowance is based on the Company's analysis of factors including changes in the size and composition of the loan portfolio, debt coverage ratios, loan to value ratios, actual loan loss experience and individual loan analysis.
	Specific Loan Loss Allowance
	An impaired commercial mortgage loan is a loan where the Company does not expect to receive contractual principal and interest in accordance with the terms of the original loan agreement. A specific allowance for losses is recorded when a loan is considered to be impaired and it is probable that all amounts due will not be collected based on the terms of the original note. The Company also holds specific loan loss allowances on certain performing commercial mortgage loans that it continues to monitor and evaluate. Impaired commercial mortgage loans without specific allowances for losses are those for which the Company has determined that it remains probable that all amounts due will be collected although the timing or nature may be outside the original contractual terms. In addition, for impaired commercial mortgage loans, the Company evaluates the cost to dispose of the underlying collateral, any significant out of pocket expenses the loan may incur and other quantitative information management has concerning the loan. Portions of loans that are deemed uncollectible are charged-off against the allowance, and recoveries, if any, are credited to the allowance. See “Note 10—Investments—Commercial Mortgage Loans.”
	Interest Income
	The Company records interest income in net investment income and continues to recognize interest income on delinquent commercial mortgage loans until the loans are more than 90 days delinquent. Interest income and accrued interest receivable are reversed when a loan is more than 90 days delinquent. For loans that are less than 90 days delinquent, management may reverse interest income and accrued interest receivable if there is a question on the collectability of the interest. Interest income on loans in the 90-day delinquent category is recognized in the period the cash is collected. The Company resumes the recognition of interest income when the loan becomes less than 90 days delinquent and management determines it is probable that the loan will remain performing.
Real Estate	'
	Real Estate
	Real estate is comprised of two components: real estate investments and real estate acquired in satisfaction of debt through foreclosure or acceptance of deeds in lieu of foreclosure on commercial mortgage loans (“Real Estate Owned”).
	Real estate investment properties are stated at cost less accumulated depreciation. Generally, the Company depreciates this real estate using the straight-line depreciation method with useful lives varying from 30 to 40 years. Accumulated depreciation for real estate totaled $13.4 million and $12.4 million at December 31, 2013 and 2012, respectively. The Company records impairments when it is determined that the decline in fair value of an investment below its carrying value is other than temporary. The impairment loss is charged to net capital losses, and the cost basis of the investment is permanently adjusted to reflect the impairment. There were no impairment losses recorded on real estate investment properties during 2013 or 2012.
	Real Estate Owned is initially recorded at the lower of cost or net realizable value, which includes an estimate for disposal costs. This amount may be adjusted in a subsequent period as additional information is received. Real Estate Owned is initially considered an investment held for sale and is expected to be sold within one year from acquisition. For any real estate expected to be sold, an impairment charge is recorded if the Company does not expect the investment to recover its carrying value prior to the expected date of sale. Once an impairment charge has been recorded, the Company continues to review the investment for further potential impairment. Impairments recorded on Real Estate Owned were $8.7 million, $3.0 million and $15.8 million for 2013, 2012 and 2011 respectively.
All Other Investments	'
	All Other Investments
	Other invested assets include tax-advantaged investments, derivative financial instruments, policy loans and common stock. Valuation adjustments for these investments are recognized using the specific identification method.
	Tax-advantaged investments are accounted for under the equity method of accounting. These investments are structured as limited partnerships for the purpose of investing in the construction and rehabilitation of low-income housing and to provide favorable returns to investors. The Company has invested in tax-advantaged investments due to the higher returns associated with these investments relative to their perceived risk. The primary sources of investment return are tax credits and the tax benefits derived from passive losses on the investments, both of which may exhibit variability over the life of the investment. Tax credits received from these investments are reported in StanCorp's consolidated statements of income as either a reduction of state premium taxes, or a reduction of income tax. StanCorp's share of the operating losses of the limited partnerships decrease the basis in the investments and are reported as a component of net investment income. If the net present value of expected future cash flows of the tax-advantaged investments is less than the current book value of the investments, the Company evaluates whether a decline in value is other than temporary. If it is determined an OTTI exists, the investment is written down to the net present value of expected future cash flows and the OTTI is recognized as a capital loss.
	Derivative financial instruments are carried at fair value, and valuation adjustments are reported as a component of net investment income. See “Note 11—Derivative Financial Instruments.”
	Policy loans are stated at their aggregate unpaid principal balances and are secured by policy cash values.
	In November of 2013, the Company became a member of the Federal Home Loan Bank (“FHLB”) of Seattle and purchased the required common stock for membership. The common stock held by the Company relating to its membership in the FHLB of Seattle is carried at par value. The Company periodically evaluates FHLB stock for OTTI. The Company's determination of whether these investments are impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value.
	Net investment income and capital gains and losses related to separate account assets and liabilities are included in the separate account assets and liabilities.
Cash And Cash Equivalents	'
	Cash and Cash Equivalents
	Cash and cash equivalents include cash and investments purchased with original maturities of three months or less at the time of acquisition. The carrying amount of cash equivalents approximates the fair value of those instruments.
DAC, VOBA And Other Intangible Assets	'
	DAC, VOBA and Other Intangible Assets
	DAC, VOBA and other acquisition related intangible assets are generally originated through the issuance of new business or the purchase of existing business, either by purchasing blocks of insurance policies from other insurers or by the outright purchase of other companies. The Company's intangible assets are subject to impairment tests on an annual basis or more frequently if circumstances indicate that carrying values may not be recoverable.
	The Company defers certain acquisition costs that vary with and are directly related to the origination of new business and placing that business in force. Certain costs related to obtaining new business and acquiring business through reinsurance agreements have been deferred and will be amortized to accomplish matching against related future premiums or gross profits as appropriate. The Company normally defers certain acquisition-related commissions and incentive payments, certain costs of policy issuance and underwriting, and certain printing costs. Assumptions used in developing DAC and amortization amounts each period include the amount of business in force, expected future persistency, withdrawals, interest rates and profitability. These assumptions are modified to reflect actual experience when appropriate. Additional amortization of DAC is charged to current earnings to the extent it is determined that future premiums or gross profits are not adequate to cover the remaining amounts deferred. Changes in actual persistency are reflected in the calculated DAC balance. Costs that are not directly associated with the acquisition of new business are not deferred as DAC and are charged to expense as incurred. Generally, annual commissions are considered expenses and are not deferred.
	DAC for group and individual disability insurance products and group life insurance products is amortized over the life of related policies in proportion to future premiums. The Company amortizes DAC for group disability and life insurance products over the initial premium rate guarantee period, which averages 2.5 years. DAC for individual disability insurance products is amortized in proportion to future premiums over the life of the contract, averaging 20 to 25 years with approximately 50% and 75% expected to be amortized by years 10 and 15, respectively.
	The Company's individual deferred annuities and group annuity products are classified as investment contracts. DAC related to these products is amortized over the life of related policies in proportion to expected gross profits. For the Company's individual deferred annuities, DAC is generally amortized over 30 years with approximately 50% and 95% expected to be amortized by years 5 and 15, respectively. DAC for group annuity products is amortized over 10 years with approximately 80% expected to be amortized by year five.
	VOBA primarily represents the discounted future profits of business assumed through reinsurance agreements. The Company has established VOBA for a block of individual disability business assumed from Minnesota Life Insurance Company (“Minnesota Life”) and a block of group disability and group life business assumed from Teachers Insurance and Annuity Association of America (“TIAA”). VOBA is generally amortized in proportion to future premiums for group and individual disability insurance products and group life products. However, the VOBA related to the TIAA transaction associated with an in force block of group long term disability claims for which no ongoing premium is received is amortized in proportion to expected gross profits. If actual premiums or future profitability are inconsistent with the Company's assumptions, the Company could be required to make adjustments to VOBA and related amortization. The VOBA associated with the TIAA transaction is amortized in proportion to expected gross profits with an amortization period of up to 20 years. For the VOBA associated with the Minnesota Life block of business assumed, the amortization period is up to 30 years and is amortized in proportion to future premiums.
	Key assumptions, which will affect the determination of expected gross profits for determining DAC and VOBA balances, include:
	Persistency.
	Interest rates, which affect both investment income and interest credited.
	Stock market performance.
	Capital gains and losses.
	Claim termination rates.
	Amount of business in force.
	These assumptions are modified to reflect actual experience when appropriate. Although a change in a single assumption may have an impact on the calculated amortization of DAC or VOBA for balances associated with investment contracts, it is the relationship of that change to the changes in other key assumptions that determines the ultimate impact on DAC or VOBA amortization. Because actual results and trends related to these assumptions vary from those assumed, we revise these assumptions annually to reflect our current best estimate of expected gross profits. As a result of this process, known as “unlocking,” the cumulative balances of DAC and VOBA are adjusted with an offsetting benefit or charge to income to reflect changes in the period of the revision. An unlocking event generally occurs as a result of actual experience or future expectations differing from previous estimates. As a result of unlocking, the amortization schedule for future periods is also adjusted.
	Significant, unanticipated changes in key assumptions, which affect the determination of expected gross profits, may result in a large unlocking event that could have a material adverse effect on our financial position or results of operations.
	The Company's other intangible assets are subject to amortization and consist of certain customer lists from Asset Management business acquired and an individual disability marketing agreement. Customer lists have a combined estimated weighted-average remaining life of approximately 6.8 years. The marketing agreement accompanied the Minnesota Life transaction and provides access to Minnesota Life agents, some of whom now market Standard's individual disability insurance products. The Minnesota Life marketing agreement will be fully amortized by the end of 2023.
Property And Equipment, Net	'
	Property and Equipment, Net
	The following table sets forth the major classifications of the Company's property and equipment and accumulated depreciation:
				December 31,
	(In millions)			2013		2012
	Home office properties			$	136.9	$	135.3
	Office furniture and equipment				47.9		47.7
	Capitalized software				169.4		160.8
	Leasehold improvements				13.9		13
		Property and equipment, gross			368.1		356.8
	Less: accumulated depreciation				283.4		266.1
			Property and equipment, net	$	84.7	$	90.7
	Property and equipment are stated at cost less accumulated depreciation. The Company depreciates property and equipment using the straight-line method over the estimated useful lives with a half-year convention. The estimated useful lives are generally 40 years for properties, range from three to ten years for equipment and range from three to five years for capitalized software. Leasehold improvements are depreciated over the lesser of the estimated useful life of the asset or the life of the lease. Depreciation expense for 2013, 2012 and 2011 was $19.9 million, $24.1 million and $28.0 million, respectively. The Company reviews property and equipment for impairment when circumstances or events indicate the carrying amount of the asset may not be recoverable and recognizes a charge to earnings if an asset is impaired.
	Non-affiliated tenants leased 33.8%, 33.3% and 35.3% of the corporate headquarters in Portland, Oregon at December 31, 2013, 2012 and 2011, respectively. Income from the leases is included in net investment income.
Separate Account	'
	Separate Account
	Separate account assets and liabilities represent segregated funds held for the exclusive benefit of contract holders. The activities of the account primarily relate to contract holder-directed 401(k) agreements. Standard charges the separate account with asset management and plan administration fees associated with the contracts. Separate account assets are carried at fair value and separate account liabilities are carried at the amount of the related assets.
Reserves For Future Policy Benefits And Claims	'
	Reserves for Future Policy Benefits and Claims
	Benefits and expenses are matched with recognized premiums to result in recognition of profits over the life of the contracts. The match is accomplished by recording a provision for future policy benefits and unpaid claims and claim adjustment expenses. For most of the Company's product lines, management establishes and carries as a liability actuarially determined reserves that are calculated to meet the Company's obligations for future policy benefits and claims. These reserves do not represent an exact calculation of the Company's future benefit liabilities but are instead estimates based on assumptions and considerations concerning a number of factors, which include:
	The amount of premiums that the Company will receive in the future.
	The rate of return on assets the Company purchases with premiums received.
	Expected number and severity of claims.
	Expenses.
	Persistency, which is the measurement of the percentage of premiums remaining in force from year to year.
	In particular, the Company's group and individual long term disability reserves are sensitive to assumptions and considerations regarding the following factors:
	Claim incidence rates for incurred but not reported claim reserves.
	Claim termination rates.
	Discount rates used to value expected future claim payments.
	Persistency rates.
	The amount of monthly benefit paid to the insured, less reinsurance recoveries and other offsets.
	Expense rates including inflation.
	Historical delay in reporting of claims incurred.
	Assumptions may vary by:
	Age, gender and, for individual policies, occupation class of the claimant.
	Year of issue for policy reserves or incurred date for claim reserves.
	Time elapsed since disablement.
	Contract provisions and limitations.
Other Policyholder Funds	'
	Other Policyholder Funds
	Other policyholder funds are liabilities for investment-type contracts and are based on the policy account balances including accumulated interest. Other policyholder funds also include amounts related to advanced premiums of $186.1 million and $186.7 million at December 31, 2013 and 2012, respectively, and premiums on deposit and experience rated liabilities totaling $193.5 million and $216.1 million at December 31, 2013 and 2012, respectively.
Recognition Of Premiums	'
	Recognition of Premiums
	Premiums from group life and group and individual disability contracts are recognized as revenue when due. Investment-type contract fee revenues consist of charges for policy administration and surrender charges assessed during the period. Charges related to services to be performed are deferred until earned. The amounts received in excess of premiums and fees are unearned and included in other policyholder funds in the consolidated balance sheets. Experience rated refunds are computed in accordance with the terms of the contracts with certain group policyholders and are accounted for as an adjustment to premiums.
Income Taxes	'
	Income Taxes
	The Company files a U.S. consolidated income tax return that includes all subsidiaries. The Company's U.S. income tax is calculated using regular corporate income tax rates on a tax base determined by laws and regulations administered by the Internal Revenue Service (“IRS”). The Company also files corporate income tax returns in various states. The provision for income taxes includes amounts currently payable and deferred amounts that result from temporary differences between financial reporting and tax bases of assets and liabilities. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply when the temporary differences are expected to reverse.
	GAAP requires management to use a more likely than not standard to evaluate whether, based on available evidence, each deferred tax asset will be realized. A valuation allowance is recorded to reduce a deferred tax asset to the amount expected to be realized.
	Management is required to determine whether tax return positions are more likely than not to be sustained upon audit by taxing authorities. Tax benefits of uncertain tax positions, as determined and measured by this interpretation, cannot be recognized in the Company's financial statements.
	The Company records income tax interest and penalties in the income tax provision according to the Company's accounting policy. See “Note 7—Income Taxes.”
Other Comprehensive Income	'
	Other Comprehensive Income
	Other comprehensive income includes changes in unrealized capital gains and losses on fixed maturity securities, net of the related tax effects, and changes in unrealized prior service costs and credits and net gains and losses associated with the Company's employee benefit plans, net of the related tax effects.

Summary_Of_Significant_Account2

Summary Of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]	'
Property And Equipment And Accumulated Depreciation	'
						December 31,
	(In millions)					2013			2012
	Home office properties					$	136.9		$	135.3
	Office furniture and equipment						47.9			47.7
	Capitalized software						169.4			160.8
	Leasehold improvements						13.9			13
		Property and equipment, gross					368.1			356.8
	Less: accumulated depreciation						283.4			266.1
			Property and equipment, net			$	84.7		$	90.7
Components Of Accumulated Other Comprehensive Income	'
				Net Unrealized						Total
				Gains (Losses) on						Accumulated
				Fixed Maturity			Employee			Other
				Securities			Benefit			Comprehensive
	(In millions)			Available-for-Sale			Plans			Income (Loss)
	Balance, January 1, 2012			$	315.2		$	-80.1		$	235.1
		Other comprehensive income, net of tax
			before reclassification adjustment(1)		71.4			0			71.4
		Amounts reclassified from accumulated
			other comprehensive income, net of tax(2)		-3.6			6.4			2.8
	Net other comprehensive income, net of tax				67.8			6.4			74.2
	Balance, December 31, 2012				383			-73.7			309.3
		Other comprehensive (loss) income, net of tax
			before reclassification adjustment(3)		-205.3			41.2			-164.1
		Amounts reclassified from accumulated
			other comprehensive income, net of tax(4)		-4.5			-6			-10.5
	Net other comprehensive (loss) income, net of tax				-209.8			35.2			-174.6
	Balance, December 31, 2013			$	173.2		$	-38.5		$	134.7
	Net of tax expense of $38.3 million for unrealized gains on fixed maturity securities and $0.2 million for employee benefits, respectively.
	Net of tax benefit of $2.2 million for unrealized gains on fixed maturity securities and net of tax expense of $3.4 million for employee benefits.
	Net of tax benefit of $111.1 million for unrealized losses on fixed maturity securities and net of tax expense of $22.2 million for employee benefits.
	Net of tax benefit of $3.1 million for unrealized gains on fixed maturity securities and $3.2 million for employee benefits, respectively.

Net_Income_Per_Common_Share_Ta

Net Income Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2013
Net Income Per Common Share [Abstract]	'
Calculation Of Net Income Per Basic And Diluted Weighted-Average Common Shares Outstanding	'
			Years ended
			December 31,
	(Dollars in millions—except per share data)		2013			2012	2011
	Net income		$	228.5	$	138.5	$	136.7
	Basic weighted-average common shares outstanding			44,243,364		44,283,771		44,876,650
	Stock options			194,978		74,232		131,926
	Stock awards			89,063		1,888		7,494
	Diluted weighted-average common shares outstanding			44,527,405		44,359,891		45,016,070
	Net income per common share:
		Net income per basic common share	$	5.16	$	3.13	$	3.05
		Net income per diluted common share		5.13		3.12		3.04
	Antidilutive shares not included in net income per diluted common
		share calculation		292,750		2,220,045		1,974,242

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2013
Share-Based Compensation [Abstract]	'
Schedule Of Compensation Cost And Related Income Tax Benefit Under Share-Based Compensation Plans	'
		Years ended
		December 31,
	(In millions)		2013			2012			2011
	Compensation cost	$		8.3		$	6.7		$	5.9
	Related income tax benefit			2.9			2.3			2.1
Summary Of Option Activity And Options Outstanding And Exercisable	'
			Options			Weighted-Average Exercise Price			Weighted-Average Remaining Contractual Terms (Years)			Total Intrinsic Value(1)
	Outstanding, January 1, 2011			2,680,493		$	40.01			5.6		$	17,226,460
		Granted		272,785			44.18
		Exercised		-120,880			29.1
		Forfeited		-42,837			42.78
		Expired		-5,200			42.73
	Outstanding, December 31, 2011			2,784,361			40.84			5.1			5,947,355
		Granted		268,033			38.09
		Exercised		-294,226			25.67
		Forfeited		-16,300			39.56
		Expired		-37,700			45.06
	Outstanding, December 31, 2012			2,704,168			42.17			4.5			2,887,006
		Granted		211,367			44.27
		Exercised		-1,214,399			41.37
		Forfeited		-31,211			47.13
		Expired		-14,831			40.34
	Outstanding, December 31, 2013			1,655,094		$	43.02			5.6		$	38,455,709
	Options outstanding and exercisable:
		Vested or expected to be vested, December 31, 2013		1,636,282		$	43.02			5.5		$	38,004,456
		Fully vested and exercisable, December 31, 2013		1,278,866			43.24			4.7			29,430,648
	The intrinsic value of outstanding options can fluctuate significantly due to changes in the year end closing stock price from year to year.
Assumptions Used To Determine The Fair Value Of Options Granted	'
		Years ended
		December 31,
		2013			2012			2011
	Dividend yield		2.25	%		2.36	%		1.97	%
	Expected stock price volatility		45.86			47.3			46.24
	Risk-free interest rate		1.31			1.02			2.35
	Expected option lives		6.2 years			5.9 years			5.7 years
Summary Of Activity Of Performance Shares Outstanding	'
			Restricted Stock Units						Performance Shares
			Activity			Weighted-Average Grant Date Fair Value			Activity		Weighted-Average Grant Date Fair Value
	Unvested balance, January 1, 2011			0		$	0		127,658		$	34.99
		Granted		0					116,978
		Vested		0					-6,504
		Forfeited		0					-47,164
	Unvested balance, December 31, 2011			0			0		190,968			44.05
		Granted		0					179,818
		Vested		0					-9,200
		Forfeited		0					-64,790
	Unvested balance, December 31, 2012			0			0		296,796			43.14
		Granted		59,823					129,172
		Vested		0					-13,964
		Forfeited		-3,057					-114,722
	Unvested balance, December 31, 2013			56,766			38.56		297,282			40.34
Assumptions Used To Determine The Fair Value Of ESPP Embedded Option	'
		Years ended
		December 31,
		2013			2012			2011
	Dividend yield		1.69-2.44	%		2.38-3.06	%		1.85-2.11	%
	Expected stock price volatility		17.43-17.58			27.80-49.09			22.03-25.63
	Risk-free interest rate		0.07-0.11			0.06-0.13			0.10-0.18
	Expected option lives		0.5 years			0.5 years			0.5 years
Schedule Of Compensation Cost And Related Income Tax Benefit Under Employee Stock Purchase Plans Table Textblock	'
		Years ended
		December 31,
	(In millions except per share data)	2013			2012			2011
	Weighted-average grant date fair value per share for ESPP offerings	$	4.16		$	9.02		$	9.46
	Compensation cost		0.3			1.4			1.2
	Related income tax benefit		0.1			0.5			0.4

Retirement_Benefits_Tables

Retirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2013
Retirement Benefits [Abstract]	'
Reconciliation Of Changes In Pension Plans' Projected Benefit Obligations, Fair Value Of Plan Assets And Funded Status	'
								Years ended
								December 31,
	(In millions)							2013			2012			2011
	Change in projected benefit obligation:
			Projected benefit obligation at beginning of the year					$	-418.5		$	-371.6		$	-323.7
			Service cost						-10.2			-9.7			-9.2
			Interest cost						-16.7			-16.5			-17.5
			Actuarial gain (loss)						26			-29.7			-29
			Benefits paid						11			9			7.8
				Projected benefit obligation at end of the year					-408.4			-418.5			-371.6
	Change in fair value of plan assets:
			Fair value of plan assets at beginning of the year						386			349.7			292.6
			Actual return on plan assets						65.4			35.4			7
			Employer contributions						---			10			58
			Benefits paid and estimated expenses						-11			-9.1			-7.9
				Fair value of plan assets at end of the year					440.4			386			349.7
						Funded status at end of the year		$	32		$	-32.5		$	-21.9
Projected And Accumulated Benefit Obligations And Fair Value Of Plan Assets For Pension Plans	'
		December 31,
	(In millions)	2013			2012			2011
	Projected benefit obligation	$	408.4		$	418.5		$	371.6
	Accumulated benefit obligation		374.2			386.5			337.5
	Fair value of plan assets		440.4			386			349.7
Amounts Recognized In Accumulated Other Comprehensive Loss	'
			Years ended
			December 31,
	(In millions)		2013			2012			2011
	Net loss		$	31.4		$	78.3		$	70.1
	Prior service cost			2.3			2.7			3.1
		Total recognized in accumulated other comprehensive (income) loss	$	33.7		$	81		$	73.2
Components Of Net Periodic Benefit Cost, Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive (Income) Loss And Assumptions Used In Measurements	'
								Years ended
								December 31,
	(Dollars in millions)							2013			2012			2011
	Components of net periodic benefit cost:
			Service cost					$	10.3		$	9.8		$	9.3
			Interest cost						16.7			16.5			17.5
			Expected return on plan assets						-29.3			-26.5			-22.1
			Amortization of prior service cost						0.6			0.6			0.6
			Amortization of net actuarial loss						9.9			8.3			4
					Net periodic benefit cost				8.2			8.7			9.3
	Other changes in plan assets and benefit obligation recognized
		in other comprehensive (income) loss:
			Net (gain) loss						-62.2			20.9			44.1
			Amortization of prior service cost						-0.6			-0.6			-0.6
			Amortization of net actuarial loss						-9.9			-8.3			-4
					Total recognized in other comprehensive (income) loss				-72.7			12			39.5
						Total recognized in net periodic benefit cost and other
							comprehensive (income) loss	$	-64.5		$	20.7		$	48.8
	Weighted-average assumptions:
		Assumptions used for net periodic benefit cost:
			Discount rate						4	%		4.5	%		5.5	%
			Expected return on plan assets						7.7			7.69			7.68
			Rate of compensation increase						3			3.25			4.5
		Assumptions used to determine benefit obligations:
			Discount rate						4.75	%		4	%		4.5	%
			Rate of compensation increase						3.5			3			3.25
Expected Benefit Payments For Pension Plans	'
	(In millions)		Amount
	2014		$	11.8
	2015			13
	2016			14.3
	2017			15.6
	2018			17
	2019-2023			105.4
Target And Actual Weighted-Average Asset Allocations For Pension Plans	'
			December 31,
			2013			2013			2012
			Target			Actual			Actual
	Asset Category:
		Equity securities		50	%		49	%		48.9	%
		Debt securities		50			51			51.1
		Total		100	%		100	%		100	%
Estimated Fair Values Of Assets And Liabilities Measured And Recorded At Fair Value On A Recurring Basis	'
								31-Dec-13
	(In millions)							Total			Level 1			Level 2			Level 3
	Assets:
		Equity securities:
			Pooled separate account funds:
				Large cap growth				$	43		$	43		$	0		$	0
				Large cap blend					64.7			64.7			0			0
				Large cap value					21.7			21.7			0			0
				Mid cap blend					64.8			64.8			0			0
				Foreign					21.7			21.7			0			0
					Total pooled separate account funds				215.9			215.9			0			0
		Debt securities:
				Stable asset fund					224.5			0			224.5			0
					Total			$	440.4		$	215.9		$	224.5		$	0
								31-Dec-12
	(In millions)							Total			Level 1			Level 2			Level 3
	Assets:
		Equity securities:
			Pooled separate account funds:
				Large cap growth				$	39.3		$	39.3		$	0		$	0
				Large cap blend					57.5			57.5			0			0
				Large cap value					19.3			19.3			0			0
				Mid cap blend					54.7			54.7			0			0
				Foreign					18			18			0			0
					Total pooled separate account funds				188.8			188.8			0			0
		Debt securities:
				Stable asset fund					197.2			0			197.2			0
					Total			$	386		$	188.8		$	197.2		$	0
Reconciliation Of Changes In Postretirement Benefit Plans' Accumulated Benefit Obligations, Fair Value Of Plan Assets And Funded Status	'
								Years ended
								December 31,
	(In millions)							2013			2012			2011
	Change in accumulated postretirement benefit obligation:
			Accumulated postretirement benefit obligation at beginning of the year					$	-23.9		$	-41		$	-40.5
			Service cost						---			-1			-1.5
			Interest cost						-1.1			-1.8			-2.1
			Plan amendments						0.8			25.2			8
			Actuarial gain (loss)						5.2			-5.9			-5.4
			Benefits paid						1.4			0.6			0.5
				Accumulated postretirement benefit obligation at end of the year					-17.6			-23.9			-41
	Change in fair value of postretirement plan assets:
			Fair value of plan assets at beginning of the year						21.6			20.7			18.2
			Actual return on plan assets						-1.6			1.2			2.7
			Employer contributions						0.7			0.3			0.3
			Benefits paid and estimated expenses						-1.4			-0.6			-0.5
				Fair value of plan assets at end of the year					19.3			21.6			20.7
						Funded status at end of the year		$	1.7		$	-2.3		$	-20.3
Amounts Recognized In Accumulated Other Comprehensive (Income) Loss	'
			Years ended
			December 31,
	(In millions)		2013			2012			2011
	Net (gain) loss		$	-1		$	5.1		$	2.2
	Prior service credit			---			-17.1			-1
		Total recognized in accumulated other comprehensive (income) loss	$	-1		$	-12		$	1.2
Assumed Health Care Cost Trend Rates For Next Year	'
		Years ended
		December 31,
		2013			2012
	Medical		7.1	%		7.3	%
	Prescriptions		7.5			7.8
	HMO (Blended)		6			6.4
	Rate to which the cost trend is assumed to decline (the ultimate trend rate)*		4.5			4.5
	*       Year that the rate reaches the ultimate trend is 2027.
One-Percentage-Point Change In Assumed Health Care Cost Trend Rates	'
						1% Point			1% Point
	(In millions)					Increase			Decrease
	Effect on total of service and interest cost					$	0.1		$	-0.1
	Effect on postretirement benefit obligation						1.5			-1.3
Components Of Net Periodic Benefit Cost, Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Loss And Assumptions Used In Measurement Of Postretirement Benefits	'
								Years ended
								December 31,
	(Dollars in millions)							2013			2012			2011
	Components of net periodic benefit cost:
			Service cost					$	0		$	1		$	1.5
			Interest cost						1			1.8			2.1
			Expected return on plan assets						-0.8			-0.8			-0.8
			Amortization of prior service cost						-26.3			-0.4			-0.3
			Amortization of net actuarial loss						5.7			0			0.1
			Curtailment loss						0			0			0.7
					Net periodic benefit cost				-20.4			1.6			3.3
	Other changes in plan assets and benefit obligation recognized
		in other comprehensive (income) loss:
			Net loss						-3.3			5.5			6.1
			Prior service credit						0			-25.2			0
			Amortization of prior service credit						26.3			0.4			0.2
			Amortization of net actuarial loss						-5.8			0			-0.1
					Total recognized in other comprehensive loss (income)				17.2			-19.3			6.2
						Total recognized in net periodic benefit cost and other
							comprehensive (income) loss	$	-3.2		$	-17.7		$	9.5
	Weighted-average assumptions:
		Assumptions used for net periodic benefit cost:
			Discount rate						4	%		4.5	%		5.5	%
			Expected return on plan assets						4.2			4.2			4.5
			Rate of compensation increase graded by age						n/a*			n/a*			5
		Assumptions used to determine benefit obligations:
			Discount rate						4.8	%		4	%		4.5	%
			Rate of compensation increase graded by age						n/a*			n/a*			n/a*
	* Assumption for rate of compensation increase was not applicable in determining benefit obligations for 2013, 2012 and 2011or net periodic benefit cost in 2013 and 2012 due to curtailment of group term life insurance benefit as of December 31, 2011.
Expected Benefit Payments For Postretirement Benefit Plan	'
	(In millions)		Amount
	2014		$	1.3
	2015			1.3
	2016			1.3
	2017			1.2
	2018			1.2
	2019-2023			5.6
Target And Actual Weighted-Average Asset Allocations For Postretirement Medical Plan	'
				Years ended
				December 31,
				2013			2013			2012
				Target			Actual			Actual
	Asset category:
		Debt securities			95	%		96.2	%		92.6	%
		Cash and cash equivalents			5			3.8			7.4
			Total		100	%		100	%		100	%
Estimated Fair Values Of Assets And Liabilities Measured And Recorded At Fair Value On A Recurring Basis	'
								31-Dec-13
	(In millions)							Total			Level 1			Level 2			Level 3
	Assets:
		Debt securities:
			Municipal bonds					$	16.8		$	0		$	16.8		$	0
			Corporate bonds						1.8			0			1.8			0
		Cash and cash equivalents							0.7			0.7			0			0
				Total				$	19.3		$	0.7		$	18.6		$	0
								31-Dec-12
	(In millions)								Total			Level 1		Level 2			Level 3
	Assets:
		Debt securities:
			Municipal bonds					$	19		$	0		$	19		$	0
			Corporate bond						1			0			1			0
		Cash and cash equivalents							1.6			1.6			0			0
				Total				$	21.6		$	1.6		$	20		$	0

Segments_Tables

Segments (Tables)	12 Months Ended
	Dec. 31, 2013
Segments [Abstract]	'
Intersegment Administrative Fee Revenues	'
		Years ended
		December 31,
	(In millions)	2013			2012			2011
	Intersegment administrative fee revenues	$	18.6		$	17.9		$	16.7
Premiums, Administrative Fee And Net Investment Income By Major Product Line Or Category	'
							Years ended
							December 31,
	(In millions)						2013			2012			2011
	Premiums:
		Insurance Services:
			Group life and AD&D				$	849.7		$	883.7		$	892.6
			Group long term disability					783			801.4			803.3
			Group short term disability					229			212.6			208
			Group other					78.3			78.9			81.6
			Experience rated refunds					-13.1			4			-12.5
				Total Employee Benefits				1,926.90			1,980.60			1,973.00
				Individual Disability				190.5			176.6			172.3
					Total Insurance Services premiums			2,117.40			2,157.20			2,145.30
		Asset Management:
				Retirement plans				2.2			1.9			2
				Individual annuities				4.7			4.8			6
					Total Asset Management premiums			6.9			6.7			8
						Total premiums	$	2,124.30		$	2,163.90		$	2,153.30
	Administrative fees:
		Insurance Services:
				Employee Benefits			$	15.1		$	13.7		$	12
				Individual Disability				0.2			0.2			0.3
					Total Insurance Services administrative fees			15.3			13.9			12.3
		Asset Management:
				Retirement plans				93.3			88			90
				Other financial services businesses				31.6			30.8			29.9
					Total Asset Management administrative fees			124.9			118.8			119.9
		Other						-18.6			-18			-16.7
						Total administrative fees	$	121.6		$	114.7		$	115.5
	Net investment income:
		Insurance Services:
				Employee Benefits			$	267.8		$	286		$	288.6
				Individual Disability				52.8			53.7			52.7
					Total Insurance Services net investment income			320.6			339.7			341.3
		Asset Management:
				Retirement plans				103.2			94.9			90.4
				Individual annuities				177.2			170.6			161
				Other financial services businesses				12.8			13.1			11.3
					Total Asset Management net investment income			293.2			278.6			262.7
		Other						16.1			10.2			8.8
						Total net investment income	$	629.9		$	628.5		$	612.8
Segment Information	'
					Year ended
					31-Dec-13
											Total
					Employee			Individual			Insurance			Asset
	(In millions)				Benefits			Disability			Services			Management		Other		Total
	Revenues:
		Premiums			$	1,926.90		$	190.5		$	2,117.40		$	6.9	$	0	$	2,124.30
		Administrative fees				15.1			0.2			15.3			124.9		-18.6		121.6
		Net investment income				267.8			52.8			320.6			293.2		16.1		629.9
		Net capital losses				0			0			0			0		-15.7		-15.7
				Total revenues		2,209.80			243.5			2,453.30			425		-18.2		2,860.10
	Benefits and expenses:
		Benefits to policyholders				1,515.90			121.8			1,637.70			17.7		0		1,655.40
		Interest credited				4.3			0			4.3			172.1		0		176.4
		Operating expenses				313.3			26.7			340			116.5		-13.9		442.6
		Commissions and bonuses				126.7			47.5			174.2			33.7		0		207.9
		Premium taxes				31.3			3.9			35.2			0.1		0		35.3
		Interest expense				0			0			0			0		34.4		34.4
		Net decrease (increase) in DAC,
			VOBA and other intangible assets			1.9			-12.4			-10.5			5.6		0		-4.9
				Total benefits and expenses		1,993.40			187.5			2,180.90			345.7		20.5		2,547.10
	Income (loss) before income taxes				$	216.4		$	56		$	272.4		$	79.3	$	-38.7	$	313
	Total assets				$	5,744.70		$	2,343.40		$	8,088.10		$	12,777.10	$	528.1	$	21,393.30
					Year ended
					31-Dec-12
											Total
					Employee			Individual			Insurance			Asset
	(In millions)				Benefits			Disability			Services			Management		Other		Total
	Revenues:
		Premiums			$	1,980.60		$	176.6		$	2,157.20		$	6.7	$	0	$	2,163.90
		Administrative fees				13.7			0.2			13.9			118.8		-18		114.7
		Net investment income				286			53.7			339.7			278.6		10.2		628.5
		Net capital losses				0			0			0			0		-8.7		-8.7
				Total revenues		2,280.30			230.5			2,510.80			404.1		-16.5		2,898.40
	Benefits and expenses:
		Benefits to policyholders				1,657.10			116.2			1,773.30			19.7		0		1,793.00
		Interest credited				4.2			0			4.2			167.1		0		171.3
		Operating expenses				323.6			25.5			349.1			117.4		4		470.5
		Commissions and bonuses				125.1			47.6			172.7			31		0		203.7
		Premium taxes				33.6			3.9			37.5			0		0		37.5
		Interest expense				0			0			0			0		39.9		39.9
		Net decrease (increase) in DAC,
			VOBA and other intangible assets			6.9			-12.7			-5.8			4.9		0		-0.9
				Total benefits and expenses		2,150.50			180.5			2,331.00			340.1		43.9		2,715.00
	Income (loss) before income taxes				$	129.8		$	50		$	179.8		$	64	$	-60.4	$	183.4
	Total assets				$	5,991.40		$	2,259.40		$	8,250.80		$	11,046.00	$	494.5	$	19,791.30
					Year ended
					31-Dec-11
											Total
					Employee			Individual			Insurance			Asset
	(In millions)				Benefits			Disability			Services			Management		Other		Total
	Revenues:
		Premiums			$	1,973.00		$	172.3		$	2,145.30		$	8	$	0	$	2,153.30
		Administrative fees				12			0.3			12.3			119.9		-16.7		115.5
		Net investment income				288.6			52.7			341.3			262.7		8.8		612.8
		Net capital losses				0			0			0			0		-6.9		-6.9
				Total revenues		2,273.60			225.3			2,498.90			390.6		-14.8		2,874.70
	Benefits and expenses:
		Benefits to policyholders				1,635.00			115.9			1,750.90			20.3		0		1,771.20
		Interest credited				4.6			0			4.6			156.4		0		161
		Operating expenses				312.3			26.4			338.7			115.2		17.3		471.2
		Commissions and bonuses				137.1			48			185.1			33.6		0		218.7
		Premium taxes				33			3.6			36.6			0.1		0		36.7
	Interest expense				0			0			0			0		38.9		38.9
	Net (increase) decrease in DAC,
		VOBA and other intangible assets			-4.3			-13.9			-18.2			3.7		0		-14.5
			Total benefits and expenses		2,117.70			180			2,297.70			329.3		56.2		2,683.20
Income (loss) before income taxes				$	155.9		$	45.3		$	201.2		$	61.3	$	-71	$	191.5
Total assets				$	6,002.90		$	2,201.90		$	8,204.80		$	9,922.90	$	275.5	$	18,403.20

Parent_Holding_Company_Condens1

Parent Holding Company Condensed Financial Information (Tables)	12 Months Ended
	Dec. 31, 2013
Parent Holding Company Condensed Financial Information [Abstract]	'
Condensed Statements Of Income	'
					Years ended
					December 31,
	(In millions)					2013			2012			2011
	Revenues:
		Net investment income				$	13.2		$	5		$	0
		Net capital gains (losses)					0.2			0.1			-0.3
				Total revenues			13.4			5.1			-0.3
	Expenses:
		Interest expense					34.2			39.7			38.8
		Operating expenses					0.9			4.5			11.2
				Total expenses			35.1			44.2			50
	Loss before income taxes and equity in net income of subsidiaries						-21.7			-39.1			-50.3
	Income tax benefit						-7.7			-14.2			-10.8
	Equity in net income of subsidiaries						242.5			163.4			176.2
	Net income						228.5			138.5			136.7
	Other comprehensive income (loss), net of tax:
		Other comprehensive income from parent					47			1.7			0
		Other comprehensive (loss) income from subsidiaries					-221.6			72.5			74.2
			Total other comprehensive (loss) income, net of tax				-174.6			74.2			74.2
	Comprehensive income					$	53.9		$	212.7		$	210.9
Condensed Balance Sheets	'
					December 31,
	(In millions)				2013			2012
	A S S E T S
	Cash and cash equivalents				$	125.2		$	39.7
	Investment in subsidiaries					2,252.90			2,352.50
	Receivable from subsidiaries					1.5			1.2
	Surplus note receivable from subsidiary					250			250
	Other assets					80.3			114.3
				Total assets	$	2,709.90		$	2,757.70
	L I A B I L I T I E S A N D S H A R E H O L D E R S’ E Q U I T Y
	Liabilities:
		Long-term debt			$	550		$	550
		Other liabilities				7.1			38.7
			Total liabilities			557.1			588.7
	Shareholders’ equity:
			Total shareholders' equity			2,152.80			2,169.00
				Total liabilities and shareholders’ equity	$	2,709.90		$	2,757.70
Condensed Statements Of Cash Flows	'
					Years ended
					December 31,
	(In millions)				2013				2012		2011
	Operating:
		Net income			$	228.5		$	138.5		$	136.7
		Adjustments to reconcile net income to net cash provided by operating activities:
			Equity in net income of subsidiaries			-242.5			-163.4			-176.2
			Dividends received from consolidated subsidiaries			147			328.7			94.3
			Changes in operating assets and liabilities			23.7			-2.5			-24.5
				Net cash provided by operating activities		156.7			301.3			30.3
	Investing:
		Capital contributions to subsidiaries				-0.7			-14.5			-9
		Return of capital from subsidiaries				7.8			7.3			76.1
		Surplus note receivable from subsidiary				0			-250			0
		Receivables from subsidiaries, net				-0.3			3.4			13.3
		Investment securities and other				0.2			1.4			0.3
				Net cash provided by (used in) investing activities		7			-252.4			80.7
	Financing:
		Issuance and repurchase of common stock, net				-29.7			0.9			-81.3
		Repayment of debt				0			-250			0
		Issuance of debt, net of issuance costs				0			246.7			0
		Dividends paid on common stock				-48.5			-41.3			-39.3
				Net cash used in financing activities		-78.2			-43.7			-120.6
	Increase (decrease) in cash and cash equivalents					85.5			5.2			-9.6
	Cash and cash equivalents, beginning of year					39.7			34.5			44.1
	Cash and cash equivalents, end of year				$	125.2		$	39.7		$	34.5

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2013
Income Taxes Disclosure [Abstract]	'
Provision For Income Taxes	'
			Years ended
			December 31,
	(In millions)		2013			2012			2011
	Current		$	71.1		$	38.5		$	40.5
	Deferred			13.4			6.4			14.3
		Total income tax provision	$	84.5		$	44.9		$	54.8
Reconciliation Between Taxes Calculated Federal Corporate Tax On Income Before Income Taxes And Recorded Income Tax Provision	'
				Years ended
				December 31,
	(In millions)			2013			2012			2011
	Tax at federal corporate rate of 35%			$	109.6		$	64.2		$	67
	(Decrease) increase in rate resulting from:
		Tax exempt interest			-			-0.1			-0.1
		Dividends received deduction			-3.6			-3.6			-3.1
		State income taxes, net of federal benefit			1.3			0.2			-0.1
		Federal tax credits			-24.9			-17.4			-8.6
		Other			2.1			1.6			-0.3
			Total income tax provision	$	84.5		$	44.9		$	54.8
Net Deferred Tax Asset (Liability)	'
					December 31,
	(In millions)				2013			2012			2011
	Policyholder liabilities				$	1.2		$	1.8		$	9.3
	Compensation and benefit plans					12.6			44			42.4
	Loss carryforwards					49.7			51.7			56.2
	Investments					45.6			35.8			41.4
	Other					3.5			2.2			1.9
		Total deferred tax assets				112.6			135.5			151.2
	Less: valuation allowances					-9.5			-3.1			-4.2
			Net deferred tax assets			103.1			132.4			147
	Net unrealized capital gains					95.7			210			173.9
	Capitalized software					6.8			8.3			10.2
	Deferred policy acquisition costs					63.5			59.7			61.6
	Intangible assets					0.9			2			3.2
	Other					0.9			0.5			1.1
		Total deferred tax liabilities				167.8			280.5			250
			Net deferred tax liability		$	-64.7		$	-148.1		$	-103

Fair_Value_Tables

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2013
Fair Value [Abstract]	'
Estimated Fair Value and the Carrying Value of Each Financial Instrument Categorized by Fair Value Hierarcy	'
							31-Dec-13
							Carrying			Fair
	(In millions)						Value			Value			Level 1		Level 2		Level 3
	Assets:
		Fixed maturity securities:
			Corporate bonds				$	6,545.70		$	6,545.70		$	0	$	6,429.70	$	116
			U.S. government and agency bonds					353.2			353.2			0		353.2		0
			U.S. state and political subdivision bonds					140.3			140.3			0		140.3		0
			Foreign government bonds					65.5			65.5			0		65.5		0
			S&P 500 Index options					15.8			15.8			0		0		15.8
				Total fixed maturity securities			$	7,120.50		$	7,120.50		$	0	$	6,988.70	$	131.8
		Commercial mortgage loans, net					$	5,405.10		$	5,769.60		$	0	$	0	$	5,769.60
		Policy loans						2.5			2.5			0		0		2.5
		Separate account assets						6,393.20			6,393.20			6,249.20		144		0
	Liabilities:
		Total other policyholder funds, investment
			type contracts				$	5,469.80		$	5,632.70		$	0	$	0	$	5,632.70
		Index-based interest guarantees						67.6			67.6			0		0		67.6
		Short-term debt						1.5			1.9			0		1.9		0
		Long-term debt						551.9			553.6			0		553.6		0
							31-Dec-12
							Carrying			Fair
	(In millions)						Value			Value			Level 1		Level 2		Level 3
	Assets:
		Fixed maturity securities:
			Corporate bonds				$	6,525.90		$	6,525.90		$	0	$	6,445.50	$	80.4
			U.S. government and agency bonds					413			413			0		411.9		1.1
			U.S. state and political subdivision bonds					168.4			168.4			0		166.7		1.7
			Foreign government bonds					72.1			72.1			0		72.1		0
			S&P 500 Index options					11.3			11.3			0		0		11.3
				Total fixed maturity securities			$	7,190.70		$	7,190.70		$	0	$	7,096.20	$	94.5
		Commercial mortgage loans, net					$	5,267.40		$	5,946.30		$	0	$	0	$	5,946.30
		Policy loans						2.5			2.5			0		0		2.5
		Separate account assets						5,154.30			5,154.30			5,007.50		146.8		0
	Liabilities:
		Total other policyholder funds, investment
			type contracts				$	4,916.70		$	5,331.30		$	0	$	0	$	5,331.30
		Index-based interest guarantees						57.4			57.4			0		0		57.4
		Short-term debt						1			1.2			0		1.2		0
		Long-term debt						551.4			567.4			0		567.4		0
Valuation Techniques Fair Values Of Assets And Liabilities Measured And Recorded At Fair Value On A Recurring Basis	'
								31-Dec-13					31-Dec-12
								Fair			Range		Fair		Range
	(Dollars in millions)			Valuation Technique		Unobservable Input		Value			of inputs		Value		of inputs
	S&P 500 Index options			Black-Scholes option pricing model		Various assumptions		$	15.8		(a)		$	11.3	(a)
	Index-based interest			Discounted cash		Expected future		$	67.6		1% - 6%		$	57.4	1% - 5%
		guarantees		flow		option purchase
						Various assumptions					(b)				(b)
				Black-Scholes option pricing model		Various assumptions					(a)				(a)
	Commercial mortgage loans			Appraisals		Reduction on appraisal		$	68.7		0% - 13%		$	53.9	0% - 38%
				Cash flows		Capitalization rate (c)					7% - 16%				7% - 14%
	Real Estate Owned			Appraisals		Reduction on appraisal		$	35.2		0%- 53%		$	48.2	0%- 36%
	Represents various assumptions derived from market data, which include estimates of bid ask spreads and the implied volatilities for the S&P 500 Index.
	Represents various actuarial assumptions which include combined lapse, mortality and withdrawal decrement rates which generally have a range of inputs from 5%-36% for both December 31, 2013 and December 31, 2012.
	Capitalization rates are used as an internal analysis in converting the underlying property's income to an estimated property value.
Reconciliation For All Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Significant Unobservable Level 3 Inputs	'
				Year ended December 31, 2013
				Assets													Liabilities
				U.S.			U.S. State										Index-
				Government			and Political						S&P 500				Based
				and Agency			Subdivision			Corporate			Index		Total		Interest
	(In millions)			Bonds			Bonds			Bonds			Options		Assets		Guarantees
	Beginning balance			$	1.1		$	1.7		$	80.4		$	11.3	$	94.5	$	57.4
	Total realized/unrealized gains (losses):
		Included in net income			0			0			0			14.4		14.4		9
		Included in other comprehensive income (loss)			0			0			6.2			0		6.2		0
	Purchases, issuances, sales and settlements:
		Purchases			0			0			0			9.4		9.4		0
		Issuances			0			0			0			0		0		6
		Sales			0			0			0			0		0		0
		Settlements			0			0			0			-19.3		-19.3		-4.8
	Transfers into level 3				0			0			61.6			0		61.6		0
	Transfers out of level 3				-1.1			-1.7			-32.2			0		-35		0
	Ending balance			$	0		$	0		$	116		$	15.8	$	131.8	$	67.6
				Year ended December 31, 2012
				Assets													Liabilities
				U.S.			U.S. State										Index-
				Government			and Political						S&P 500				Based
				and Agency			Subdivision			Corporate			Index		Total		Interest
	(In millions)			Bonds			Bonds			Bonds			Options		Assets		Guarantees
	Beginning balance			$	0.5		$	1.4		$	64		$	7.2	$	73.1	$	49.5
	Total realized/unrealized gains (losses):
		Included in net income			0			0			0			7.8		7.8		6.4
		Included in other comprehensive income (loss)			0			-0.1			8			0		7.9		0
	Purchases, issuances, sales and settlements:
		Purchases			1.1			0			12.1			9.5		22.7		0
		Issuances			0			0			0			0		0		4.9
		Sales			0			0			-2.2			0		-2.2		0
		Settlements			0			0			0			-13.2		-13.2		-3.4
	Transfers into level 3				0			0.4			8			0		8.4		0
	Transfers out of level 3				-0.5			0			-9.5			0		-10		0
	Ending balance			$	1.1		$	1.7		$	80.4		$	11.3	$	94.5	$	57.4
Changes In Unrealized Gains (Losses) Included In Net Income Relating To Positions Still Held	'
			Years ended
			December 31,
	(In millions)		2013			2012
	Assets:
		S&P 500 Index options	$	6.4		$	1.8
	Liabilities:
		Index-based interest guarantees	$	-12.9		$	-7.8
Assets Measured At Fair Value On A Nonrecurring Basis And Still Held As Of The Balance Sheet Date	'
			31-Dec-13
	(In millions)		Total			Level 1			Level 2			Level 3
	Commercial mortgage loans		$	68.7		$	0		$	0		$	68.7
	Real Estate Owned			35.2			0			0			35.2
		Total assets measured at fair value on a nonrecurring basis	$	103.9		$	0		$	0		$	103.9
			31-Dec-12
	(In millions)		Total			Level 1			Level 2			Level 3
	Commercial mortgage loans		$	53.9		$	0		$	0		$	53.9
	Real Estate Owned			48.2			0			0			48.2
		Total assets measured at fair value on a nonrecurring basis	$	102.1		$	0		$	0		$	102.1

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2013
Investments [Abstract]	'
Amortized Costs And Fair Values Of Fixed Maturity Securities Available-For-Sale	'
			December 31,
			2013
			Amortized			Unrealized			Unrealized			Fair
	(In millions)		Cost			Gains			Losses			Value
	Corporate bonds		$	6,282.10		$	339.6		$	-76		$	6,545.70
	U.S. government and agency bonds			320.8			32.8			-0.4			353.2
	U.S. state and political subdivision bonds			134.3			6.8			-0.8			140.3
	Foreign government bonds			58.9			6.6			0			65.5
	S&P 500 Index options			15.8			0			0			15.8
		Total fixed maturity securities	$	6,811.90		$	385.8		$	-77.2		$	7,120.50
			December 31,
			2012
			Amortized			Unrealized			Unrealized			Fair
	(In millions)		Cost			Gains			Losses			Value
	Corporate bonds		$	5,942.00		$	587.7		$	-3.8		$	6,525.90
	U.S. government and agency bonds			351.5			61.5			0			413
	U.S. state and political subdivision bonds			151.6			16.8			0			168.4
	Foreign government bonds			61.3			10.8			0			72.1
	S&P 500 Index options			11.3			0			0			11.3
		Total fixed maturity securities	$	6,517.70		$	676.8		$	-3.8		$	7,190.70
Schedule Of Contractual Maturities Of Fixed Maturity Securities Available-For-Sale	'
			31-Dec-13						31-Dec-12
			Amortized			Fair			Amortized			Fair
	(In millions)		Cost			Value			Cost			Value
	Due in one year or less		$	486.2		$	495.1		$	699.2		$	712.9
	Due after one year through five years			2,974.50			3,168.90			2,779.90			3,009.10
	Due after five years through ten years			2,497.50			2,524.60			2,184.70			2,422.60
	Due after ten years			853.7			931.9			853.9			1,046.10
		Total fixed maturity securities	$	6,811.90		$	7,120.50		$	6,517.70		$	7,190.70
Schedule Of Gross Unrealized Losses And Fair Value Of Investments	'
					31-Dec-13
					Total						Less than 12 months						12 or more months
	(Dollars in millions)				Number			Amount			Number			Amount			Number			Amount
	Unrealized losses:
			U.S. state and political subdivision bonds			10		$	0.8			10		$	0.8			0		$	0
			U.S. government and agency bonds			9			0.4			9			0.4			0			0
			Corporate bonds			908			76			848			66.3			60			9.7
				Total		927		$	77.2			867		$	67.5			60		$	9.7
	Fair market value of securities with
		unrealized losses:
			U.S. state and political subdivision bonds			10		$	15.4			10		$	15.4			0		$	0
			U.S. government and agency bonds			9			16.9			9			16.9			0			0
			Corporate bonds			908			1,663.80			848			1,557.70			60			106.1
				Total		927		$	1,696.10			867		$	1,590.00			60		$	106.1
					31-Dec-12
					Total						Less than 12 months						12 or more months
	(Dollars in millions)				Number			Amount			Number			Amount			Number			Amount
	Unrealized losses:
			Corporate bonds			198		$	3.8			188		$	3.6			10		$	0.2
	Fair market value of securities with
		unrealized losses:
			Corporate bonds			198		$	342.5			188		$	335.5			10		$	7
Commercial Mortgage Loan Portfolio By Property Type, By Geographic Region Within The U.S. And By U.S. State	'
				31-Dec-13						31-Dec-12
	(Dollars in millions)			Amount			Percent			Amount			Percent
	Property type:
		Retail		$	2,629.20		48.6	%		$	2,560.70		48.6	%
		Industrial			1,008.70		18.7				995.8		18.9
		Office			982.4		18.2				960.8		18.2
		Hotel/motel			276.3		5.1				280.8		5.3
		Commercial			218.6		4				205.3		4
		Apartment and other			289.9		5.4				264		5
			Total commercial mortgage loans, net	$	5,405.10		100	%		$	5,267.40		100	%
	Geographic region*:
		Pacific		$	1,910.10		35.3	%		$	1,844.10		35	%
		South Atlantic			1,090.00		20.2				1,069.20		20.2
		West South Central			672.8		12.4				634.8		12.1
		Mountain			611.4		11.3				612.7		11.6
		East North Central			473.8		8.8				443.9		8.4
		Middle Atlantic			223		4.1				240.3		4.6
		West North Central			186.9		3.5				183		3.5
		East South Central			166.6		3.1				150.5		2.9
		New England			70.5		1.3				88.9		1.7
			Total commercial mortgage loans, net	$	5,405.10		100	%		$	5,267.40		100	%
	U.S. state:
		California		$	1,455.50		26.9	%		$	1,436.30		27.3	%
		Texas			618.8		11.5				587		11.1
		Florida			331.6		6.1				331.9		6.3
		Georgia			310.7		5.8				311.5		5.9
		Other states			2,688.50		49.7				2,600.70		49.4
			Total commercial mortgage loans, net	$	5,405.10		100	%		$	5,267.40		100	%
	*        Geographic regions obtained from the American Council of Life Insurers Mortgage Loan Portfolio Profile.
Changes In Commercial Mortgage Loan Loss Allowance	'
				Years ended
				December 31,
	(In millions)			2013			2012
	Commercial mortgage loan loss allowance:
	Beginning balance			$	46.6		$	48.1
		Provision			15.9			13.4
		Charge-offs, net			-18.9			-14.9
			Ending balance	$	43.6		$	46.6
	Specific loan loss allowance			$	25.9		$	25.6
	General loan loss allowance				17.7			21
			Total commercial mortgage loan loss allowance	$	43.6		$	46.6
Schedule Of Recorded Investment In Commercial Mortgage Loans	'
				December 31,
	(In millions)			2013			2012
	Commercial mortgage loans collectively evaluated for impairment			$	5,334.40		$	5,214.20
	Commercial mortgage loans individually evaluated for impairment				114.3			99.8
	Commercial mortgage loan loss allowance				-43.6			-46.6
			Total commercial mortgage loans, net	$	5,405.10		$	5,267.40
Performing And Nonperforming Commercial Mortgage Loans By Property Type	'
				31-Dec-13
													Hotel/						Apartment
	(In millions)			Retail			Industrial			Office			Motel			Commercial			and Other			Total
	Performing commercial mortgage
		loans		$	2,624.20		$	1,004.60		$	979.6		$	276.3		$	218.6		$	289.9		$	5,393.20
	Nonperforming commercial
		mortgage loans			5			4.1			2.8			0			0			0			11.9
			Total commercial mortgage loans	$	2,629.20		$	1,008.70		$	982.4		$	276.3		$	218.6		$	289.9		$	5,405.10
				31-Dec-12
													Hotel/						Apartment
	(In millions)			Retail			Industrial			Office			Motel			Commercial			and Other			Total
	Performing commercial mortgage
		loans		$	2,552.50		$	993		$	955.8		$	280.8		$	204.7		$	263.5		$	5,250.30
	Nonperforming commercial
		mortgage loans			8.2			2.8			5			0			0.6			0.5			17.1
			Total commercial mortgage loans	$	2,560.70		$	995.8		$	960.8		$	280.8		$	205.3		$	264		$	5,267.40
Impaired Commercial Mortgage Loans Identified In Management's Specific Review Of Probable Loan Losses And The Related Allowance	'
							31-Dec-13
										Unpaid						Amount on
							Recorded			Principal			Related			Nonaccrual
	(In millions)						Investment			Balance			Allowance			Status
	Impaired commercial mortgage loans:
		Without specific loan loss allowances:
			Retail				$	16.1		$	16.1		$	0		$	7.6
			Office					3.9			3.9			0			1.5
			Industrial					1			1			0			0
			Commercial					1.8			1.8			0			0
			Apartment and other					3.8			3.8			0			0
				Total impaired commercial mortgage loans without specific
					loan loss allowances			26.6			26.6			0			9.1
		With specific loan loss allowances:
			Retail					58.5			58.5			16.1			21.6
			Office					9.7			9.7			3.8			0.9
			Industrial					12.6			12.6			2.4			1.4
			Commercial					6			6			3.6			2.5
			Apartment and other					0.9			0.9			0			0
				Total impaired commercial mortgage loans with specific
					loan loss allowances			87.7			87.7			25.9			26.4
						Total impaired commercial mortgage loans	$	114.3		$	114.3		$	25.9		$	35.5
							31-Dec-12
										Unpaid						Amount on
							Recorded			Principal			Related			Nonaccrual
	(In millions)						Investment			Balance			Allowance			Status
	Impaired commercial mortgage loans:
		Without specific loan loss allowances:
			Retail				$	15.3		$	15.3		$	0		$	2.2
			Office					5.2			5.2			0			4.1
			Industrial					3.3			3.3			0			0.2
			Apartment and other					1.9			1.9			0			0
				Total impaired commercial mortgage loans without specific
					loan loss allowances			25.7			25.7			0			6.5
		With specific loan loss allowances:
			Retail					37.9			37.9			13.2			9.3
			Office					10.3			10.3			2.5			1.3
			Industrial					11.4			11.4			3.6			2
			Commercial					11.4			11.4			6.2			2.7
			Apartment and other					3.1			3.1			0.1			0
				Total impaired commercial mortgage loans with specific
					loan loss allowances			74.1			74.1			25.6			15.3
						Total impaired commercial mortgage loans	$	99.8		$	99.8		$	25.6		$	21.8
Information Related To Troubled Debt Restructurings Of Financing Receivables	'
							Year ended
							31-Dec-13
										Pre-			Post-
										Restructuring			Restructuring
							Number of			Recorded			Recorded
	(Dollars in millions)						Loans			Investment			Investment
	Troubled debt restructurings:
			Retail					16		$	20		$	20.8
			Office					3			1.6			1.6
			Industrial					2			2.2			2.3
			Commercial					1			0.9			0.9
				Total troubled debt restructurings				22		$	24.7		$	25.6
							Year ended
							31-Dec-12
										Pre-			Post-
										Restructuring			Restructuring
							Number of			Recorded			Recorded
	(Dollars in millions)						Loans			Investment			Investment
	Troubled debt restructurings:
			Retail					8		$	8		$	9.2
			Industrial					3			2.4			2.4
			Commercial					1			1			1
			Apartment and other					1			1.8			1.9
				Total troubled debt restructurings				13		$	13.2		$	14.5
Average Recorded Investment In Impaired Commercial Mortgage Loans Before Specific Allowances For Losses	'
		Years ended December 31,
	(In millions)	2013			2012			2011
	Average recorded investment	$	113.4		$	101.3		$	92.3
Aging Of Commercial Mortgage Loans By Property Type	'
				31-Dec-13
																						Total
										Greater Than						Allowance						Commercial
				30 Days			60 Days			90 Days			Total			Related			Current,			Mortgage
	(In millions)			Past Due			Past Due			Past Due			Past Due			to Past Due			Net			Loans
	Commercial mortgage loans:
		Retail		$	2.8		$	0.3		$	6.1		$	9.2		$	-1.5		$	2,621.50		$	2,629.20
		Office			1.3			0			3.7			5			-0.9			978.3			982.4
		Industrial			0			3.3			1.8			5.1			-0.9			1,004.50			1,008.70
		Hotel/motel			6.3			0			0			6.3			0			270			276.3
		Commercial			0			0			0			0			0			218.6			218.6
		Apartment and other			0			0			0			0			0			289.9			289.9
			Total commercial mortgage loans	$	10.4		$	3.6		$	11.6		$	25.6		$	-3.3		$	5,382.80		$	5,405.10
				31-Dec-12
																						Total
										Greater Than						Allowance						Commercial
				30 Days			60 Days			90 Days			Total			Related			Current,			Mortgage
	(In millions)			Past Due			Past Due			Past Due			Past Due			to Past Due			Net			Loans
	Commercial mortgage loans:
		Retail		$	17.2		$	4.9		$	4.7		$	26.8		$	-1.4		$	2,535.30		$	2,560.70
		Office			4.1			0			5.6			9.7			-0.6			951.7			960.8
		Industrial			1.6			0.5			3.6			5.7			-1.4			991.5			995.8
		Hotel/motel			0			0			0			0			0			280.8			280.8
		Commercial			2.7			0			1.4			4.1			-0.8			202			205.3
		Apartment and other			0			0.6			0			0.6			0			263.4			264
			Total commercial mortgage loans	$	25.6		$	6		$	15.3		$	46.9		$	-4.2		$	5,224.70		$	5,267.40
Net Investment Income Summarized By Investment Type	'
						Years ended
						December 31,
	(In millions)						2013			2012		2011
	Fixed maturity securities:
		Bonds				$	303		$	316.8		$	323.6
		S&P 500 Index options					14.4			7.8			-0.2
			Total fixed maturity securities				317.4			324.6			323.4
	Commercial mortgage loans						341.7			331.9			310.2
	Real estate						-1.4			-1			-0.4
	Other						9			8.6			8
				Gross investment income			666.7			664.1			641.2
	Investment expenses						-22.9			-22.3			-21.8
	Tax-advantaged investment operating losses						-13.9			-13.3			-6.6
					Net investment income	$	629.9		$	628.5		$	612.8
Schedule Of Gross Capital Gains And Losses By Investment Type	'
					Years ended
					December 31,
	(In millions)				2013			2012			2011
	Gains:
		Fixed maturity securities			$	9.8		$	10.8		$	11.5
		Commercial mortgage loans				2.4			1.5			0.9
		Real estate investments				0.7			---			35.2
		Real estate owned				2.3			1.3			1.1
		Other				0.2			0.6			0
			Gross capital gains			15.4			14.2			48.7
	Losses:
		Fixed maturity securities				-2.3			-5			-2.4
		Provision for commercial mortgage loan losses				-15.9			-13.4			-32.7
		Real estate investments				-0.1			0			-0.5
		Real estate owned				-9.5			-3.5			-17.6
		Other				-3.3			-1			-2.4
			Gross capital losses			-31.1			-22.9			-55.6
				Net capital losses	$	-15.7		$	-8.7		$	-6.9

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2013
Derivative Financial Instruments [Abstract]	'
Fair Value Of The Company's Derivative Assets And Liabilities	'
	Derivatives Not Designated as Hedging Instruments			December 31,
	(In millions)			2013		2012
	Assets:
		Fixed maturity securities:
			S&P 500 Index options	$	15.8	$	11.3
	Liabilities:
		Other policyholder funds:
			Index-based interest guarantees	$	67.6	$	57.4
Gain Or Loss Recognized In Earnings From The Change In Fair Value Of Derivative Assets And Liabilities	'
	Derivatives Not Designated as Hedging Instruments			Years ended December 31,
	(In millions)			2013		2012		2011
	Net investment income:
		S&P 500 Index options		$	14.4	$	7.8	$	-0.2
	Interest credited:
		Index-based interest guarantees			-9		-6.4		-1.3
			Net gain (loss)	$	5.4	$	1.4	$	-1.5
Fair Value Of Derivative Assets And Maximum Credit Risk Exposure	'
				31-Dec-13
				Assets at		Maximum
	(In millions)			Fair Value		Credit Risk
	Counterparty:
		The Bank of New York Mellon		$	11	$	14.3
		Goldman Sachs			4.8		5.9
			Total	$	15.8	$	20.2

Deferred_Acquisition_Costs_DAC1

Deferred Acquisition Costs ("DAC"), Value Of Business Acquired ("VOBA") And Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2013
Deferred Acquisition Costs Value Of Business Acquired And Other Intangible Assets Disclosures [Abstract]	'
Schedule Of Activity For DAC, VOBA And Other Intangible Assets	'
				Years ended
				December 31,
	(In millions)			2013			2012			2011
	Carrying value at beginning of year, net:
		DAC		$	284.9		$	274.4		$	250.1
		VOBA			23.4			26.4			28.4
		Other intangible assets			38.2			44.1			51.7
			Total balance at beginning of year		346.5			344.9			330.2
	Deferred or acquired:
		DAC			76.9			71.4			81.7
			Total deferred or acquired		76.9			71.4			81.7
	Amortized during year:
		DAC			-42.7			-60.9			-57.4
		VOBA			-3.3			-3			-2
		Other intangible assets			-6.1			-5.9			-7.6
			Total amortized during year		-52.1			-69.8			-67
	Carrying value at end of year, net:
		DAC			319.1			284.9			274.4
		VOBA			20.1			23.4			26.4
		Other intangible assets			32.1			38.2			44.1
			Total carrying value at end of year	$	371.3		$	346.5		$	344.9
Schedule Of DAC And VOBA Balances Amortized In Proportion To Expected Gross Profits And The Percentage Of The Total Balance Of DAC And VOBA Amortized In Proportion To Expected Gross Profits	'
		31-Dec-13						31-Dec-12
	(Dollars in millions)	Amount			Percent			Amount			Percent
	DAC	$	80.1		25.1	%		$	60.9		21.4	%
	VOBA		4.3		21.4				5.9		25.2
Impact Of Unlocking On DAC And VOBA Balances	'
		Years ended
		December 31,
	(In millions)	2013			2012			2011
	Decrease to DAC and VOBA	$	-1.7		$	-1.7		$	-0.9
Schedule Of The Estimated Net Amortization Of Value Of Business Acquired And Other Intangible Assets For The Next Five Years	'
	(In millions)	Amount
	2014	$	7.6
	2015		7.2
	2016		5.6
	2017		4.2
	2018		4.2

Liability_For_Unpaid_Claims_Cl1

Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds (Tables)	12 Months Ended
	Dec. 31, 2013
Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds [Abstract]	'
Change In The Liability For Unpaid Claims And Claim Adjustment Expenses	'
				Years ended
				December 31,
	(In millions)			2013		2012		2011
	Net balance at beginning of the year:
		Balance at beginning of the year, gross of reinsurance		$	4,005.90	$	3,857.00	$	3,716.30
		Less: reinsurance recoverable			-128.6		-117.3		-110.5
			Net balance at beginning of the year		3,877.30		3,739.70		3,605.80
	Incurred related to:
		Current year			1,081.70		1,140.30		1,077.10
		Prior year's interest			180.3		181.2		175.9
		Prior years			-133.2		-79.8		-46.5
			Total incurred		1,128.80		1,241.70		1,206.50
	Paid related to:
		Current year			-345.9		-354.8		-347.1
		Prior year			-778.2		-749.3		-725.5
			Total paid		-1,124.10		-1,104.10		-1,072.60
	Net balance at end of the year				3,882.00		3,877.30		3,739.70
		Plus: reinsurance recoverable			139.9		128.6		117.3
			Balance at end of the year, gross of reinsurance	$	4,021.90	$	4,005.90	$	3,857.00
Future Policy Benefits And Claims	'
				Years ended
				December 31,
	(In millions)			2013		2012		2011
	Future policy benefits and claims			$	5,846.90	$	5,843.20	$	5,683.60
		Less: Group life reserves			-751.7		-765.3		-765.4
		Less: Individual life reserves			-603.6		-600.9		-597.2
		Less: Group and individual annuity reserves			-220		-237.4		-244.2
		Less: Individual disability active life reserves			-249.7		-233.7		-219.8
			Liability for unpaid claims and claim adjustment expenses	$	4,021.90	$	4,005.90	$	3,857.00
Composition Of Other Policyholder Funds	'
				Years ended
				December 31,
	(In millions)			2013		2012
	Retirement plan stable asset funds			$	1,954.10	$	1,554.10
	Individual fixed-rate annuity funds				2,541.70		2,434.90
	Indexed annuity funds				440.8		409.2
	Investment only stable asset funds				326.1		336.4
	Other				788.9		796.5
		Total other policyholder funds		$	6,051.60	$	5,531.10

Reinsurance_Tables

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2013
Reinsurance [Abstract]	'
Schedule Of Reinsurance Information	'
								Assumed				Percentage of
						Ceded to		From				Amount
						Other		Other				Assumed
	(Dollars in millions)			Gross Amount		Companies		Companies		Net Amount		to Net
	2013:00:00
	Life insurance in force			$	321,881.70	$	5,966.80	$	57.7	$	315,972.60	0	%
	Premiums:
		Life insurance and annuities		$	898.5	$	48.5	$	0	$	850	0
		Accident and health insurance			1,258.60		81		96.7		1,274.30	7.6
			Total premiums	$	2,157.10	$	129.5	$	96.7	$	2,124.30	4.6
	2012:00:00
	Life insurance in force			$	346,814.50	$	7,233.10	$	65.1	$	339,646.50	0	%
	Premiums:
		Life insurance and annuities		$	937.9	$	51	$	0	$	886.9	0
		Accident and health insurance			1,263.30		83.7		97.4		1,277.00	7.6
			Total premiums	$	2,201.20	$	134.7	$	97.4	$	2,163.90	4.5
	2011:00:00
	Life insurance in force			$	350,623.10	$	55,126.00	$	71.7	$	295,568.80	0	%
	Premiums:
		Life insurance and annuities		$	942.3	$	52.2	$	0	$	890.1	0
		Accident and health insurance			1,241.80		76.1		97.5		1,263.20	7.7
			Total premiums	$	2,184.10	$	128.3	$	97.5	$	2,153.30	4.5

Insurance_Information_Tables

Insurance Information (Tables)	12 Months Ended
	Dec. 31, 2013
Insurance Information [Abstract]	'
Insurance Information	'
						Future								Benefits,
						Policy		Other				Net		Claims and		Amortization		Other
						Benefits		Policyholder		Premium		Investment		Interest		of		Operating
	(In millions)			DAC, net(1)		and Claims		Funds		Revenues		Income		Credited		DAC		Expenses (2)
	2013:00:00
	Employee Benefits			$	24.2	$	3,995.90	$	315.3	$	1,926.90	$	267.8	$	1,520.20	$	22.6	$	473.2
	Individual Disability				214.8		1,631.10		198.9		190.5		52.8		121.8		22.6		65.7
		Total Insurance
			Services		239		5,627.00		514.2		2,117.40		320.6		1,642.00		45.2		538.9
		Asset Management			80.1		219.9		5,537.40		6.9		293.2		189.8		17.7		155.9
			Total	$	319.1	$	5,846.90	$	6,051.60	$	2,124.30	$	613.8	$	1,831.80	$	62.9	$	694.8
	2012:00:00
	Employee Benefits			$	24.6	$	4,025.60	$	353.5	$	1,980.60	$	286	$	1,661.30	$	23.9	$	489.2
	Individual Disability				199.3		1,580.20		203.5		176.6		53.7		116.2		21.9		64.3
		Total Insurance
			Services		223.9		5,605.80		557		2,157.20		339.7		1,777.50		45.8		553.5
		Asset Management			61		237.4		4,974.10		6.7		278.6		186.8		15.8		153.3
			Total	$	284.9	$	5,843.20	$	5,531.10	$	2,163.90	$	618.3	$	1,964.30	$	61.6	$	706.8
	2011:00:00
	Employee Benefits			$	30.1	$	3,910.00	$	376.9	$	1,973.00	$	288.6	$	1,639.60	$	22.8	$	478.1
	Individual Disability				183.6		1,529.40		202.4		172.3		52.7		115.9		20.1		64.1
		Total Insurance
			Services		213.7		5,439.40		579.3		2,145.30		341.3		1,755.50		42.9		542.2
		Asset Management			60.7		244.2		4,498.80		8		262.7		176.7		16.2		152.6
			Total	$	274.4	$	5,683.60	$	5,078.10	$	2,153.30	$	604	$	1,932.20	$	59.1	$	694.8
	(1)       See “Note 1—Summary of Significant Accounting Policies—DAC, VOBA and Other Intangible Assets” And “Note 12—DAC, VOBA and Other Intangible Assets.”
	(2)       Other operating expenses include operating expenses, commissions and bonuses, premium taxes, interest expense and the net increase in DAC, VOBA and other intangible assets.

Regulatory_Matters_Tables

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2013
Regulatory Matters [Abstract]	'
Reconciliation of capital and surplus of the insurance to GAAP equity	'
			December 31,
	(In millions)		2013		2012
	Statutory capital and surplus		$	1,359.00	$	1,259.60
	Adjustments to reconcile to GAAP equity:
		Future policy benefits and other policyholder funds		325.8		301.7
		DAC, VOBA and other intangible assets		351.6		322
		Deferred tax liabilities		-265.3		-236.8
		Asset valuation reserve		127.5		117.5
		Valuation of investments		236.4		449.8
		Interest maintenance reserve		25.5		24.8
		Equity of StanCorp and its non-insurance subsidiaries		116.1		51.6
		Non-admitted assets		178.2		144.1
		Pension and postretirement benefit plans		-6.6		3.6
		Capital lease obligations		-3.4		-2.4
		Surplus note		-250		-250
		Other, net		-42		-16.5
	GAAP equity		$	2,152.80	$	2,169.00
Reconciliation Of The Statutory Gain From Operations to GAAP Net Income	'
			Years ended December 31,
	(In millions)		2013		2012		2011
	Statutory net income		$	198.5	$	131.5	$	125.8
	Adjustments to reconcile to GAAP net income:
		Future policy benefits and other policyholder funds		11		26.4		48
		DAC and VOBA, net of amortization		9.4		5.5		19.2
		Deferred income taxes		-13.5		-22.4		-42.1
		Current income taxes		9.6		17.2		24.7
		Earnings of StanCorp and its non-insurance subsidiaries		-8.9		-23.8		-18.9
		Deferred capital gains (interest maintenance reserve)		0.7		5		7.2
		Pension and postretirement benefit plans		17.6		-1.7		-3.1
		Share based compensation		-3.6		-5.4		-5.2
		Investments		8.5		5.8		-12.6
		Other, net		-0.8		0.4		-6.3
	GAAP net income		$	228.5	$	138.5	$	136.7

LongTerm_Debt_Tables

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2013
Long-Term Debt [Abstract]	'
Long-Term Debt	'
				December 31,
	(In millions)			2013		2012
	Long-term debt:
		Senior notes		$	250	$	250
		Subordinated debt			300		300
		Other long-term borrowings			1.9		1.4
			Total long-term debt	$	551.9	$	551.4

Commitments_And_Contingencies_

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2013
Commitments And Contingencies [Abstract]	'
Future Minimum Payments Under The Leases	'
	(In millions)
	2014	$	8.9
	2015		7.9
	2016		7.6
	2017		7.1
	2018		2.6
	Thereafter		1.8
Minimum Future Rental Receivables On Non-Cancelable Leases Of Retail And Office Space	'
	(In millions)
	2014	$	7.4
	2015		6.6
	2016		4.7
	2017		2.1
	2018		1.5
	Thereafter		5.9

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2013
AOCI, net of tax [Abstract]	'
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	'
				Net Unrealized				Total
				Gains (Losses) on				Accumulated
				Fixed Maturity		Employee		Other
				Securities		Benefit		Comprehensive
	(In millions)			Available-for-Sale		Plans		Income (Loss)
	Balance, January 1, 2012			$	315.2	$	-80.1	$	235.1
		Other comprehensive income, net of tax
			before reclassification adjustment(1)		71.4		0		71.4
		Amounts reclassified from accumulated
			other comprehensive income, net of tax(2)		-3.6		6.4		2.8
	Net other comprehensive income, net of tax				67.8		6.4		74.2
	Balance, December 31, 2012				383		-73.7		309.3
		Other comprehensive (loss) income, net of tax
			before reclassification adjustment(3)		-205.3		41.2		-164.1
		Amounts reclassified from accumulated
			other comprehensive income, net of tax(4)		-4.5		-6		-10.5
	Net other comprehensive (loss) income, net of tax				-209.8		35.2		-174.6
	Balance, December 31, 2013			$	173.2	$	-38.5	$	134.7
	Net of tax expense of $38.3 million for unrealized gains on fixed maturity securities and $0.2 million for employee benefits, respectively.
	Net of tax benefit of $2.2 million for unrealized gains on fixed maturity securities and net of tax expense of $3.4 million for employee benefits.
	Net of tax benefit of $111.1 million for unrealized losses on fixed maturity securities and net of tax expense of $22.2 million for employee benefits.
	Net of tax benefit of $3.1 million for unrealized gains on fixed maturity securities and $3.2 million for employee benefits, respectively.

Severance_Lease_Terminations_A1

Severance, Lease Terminations And Transition Costs (Tables)	12 Months Ended
	Dec. 31, 2013
Severance, Lease Terminations, And Transition Costs [Abstract]	'
Severance Lease Terminations And Transition Costs Schedule Of Expenses Incurred	'
			Years ended December 31, 2013
			Beginning						Ending
			Accrued		Charged to				Accrued
	(In millions)		Liability(1)		Expense, Net		Expenditures		Liability
	Severance		$	0.1	$	2.9	$	2.8	$	0.2
	Transition costs			0		1.3		1.3		0
	Lease terminations			0.3		0		0.3		0
		Total severance, transition costs and lease terminations	$	0.4	$	4.2	$	4.4	$	0.2
			Year Ended December 31, 2012
			Beginning						Ending
			Accrued		Charged to				Accrued
	(In millions)		Liability(1)		Expense, Net		Expenditures		Liability
	Severance		$	1	$	0	$	0.9	$	0.1
	Transition costs			0		0		0		0
	Lease terminations			1		0		0.7		0.3
		Total severance, transition costs and lease terminations	$	2	$	0	$	1.6	$	0.4
	Amounts relate to restructuring charges implemented by the Company during 2011.

Quarterly_Financial_Informatio1

Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2013
Quarterly Financial Information [Abstract]	'
Financial Information By Calendar Quarter	'
			2013
	(In millions—except per share data)		4th Quarter		3rd Quarter		2nd Quarter		1st Quarter
	Premiums		$	528.6	$	524.4	$	535.1	$	536.2
	Administrative fees			32		30.5		30.4		28.7
	Net investment income			160.8		155.8		154.1		159.2
	Net capital losses			-2.8		-8.7		-2.6		-1.6
		Total revenues		718.6		702		717		722.5
	Benefits to policyholders			394.5		395		424.1		441.8
	Net income			65		59		57.7		46.8
	Net income per common share:
		Basic	$	1.48	$	1.33	$	1.3	$	1.05
		Diluted		1.46		1.32		1.3		1.05
			2012
	(In millions—except per share data)		4th Quarter		3rd Quarter		2nd Quarter		1st Quarter
	Premiums		$	533.8	$	528.7	$	548.1	$	553.3
	Administrative fees			28.5		27.8		29.8		28.6
	Net investment income			157.6		159.8		151.4		159.7
	Net capital losses			-1.9		-2.6		-4		-0.2
		Total revenues		718		713.7		725.3		741.4
	Benefits to policyholders			444.7		422.4		475.9		450
	Net income			38.4		44.9		20		35.2
	Net income per common share:
		Basic	$	0.87	$	1.02	$	0.45	$	0.79
		Diluted		0.87		1.01		0.45		0.79

Summary_Of_Significant_Account3

Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Tax-advantage investments	$192.40	$173	'
Depreciation expense	19.9	24.1	28
Percentage of corporate headquarters leased to non-affiliated tenants	33.80%	33.30%	35.30%
Advance premiums	186.1	186.7	'
Premiums On Deposit And Experienced Rated Refunds	193.5	216.1	'
Real Estate Investment [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Accumulated depreciation, Real estate	13.4	12.4	'
Impairment on real estate owned	$8.70	$3	$15.80
Maximum Member | Real Estate Investment [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Useful life	'40 years 0 months 0 days	'	'
Minimum Member | Real Estate Investment [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Useful life	'30 years 0 months 0 days	'	'
Customer Lists [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Intangible Assets, Useful Life	'6 years 9 months 18 days	'	'
Properties	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Useful life	'40 years 0 months 0 days	'	'
Equipment [Member] | Maximum Member	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Useful life	'10 years 0 months 0 days	'	'
Equipment [Member] | Minimum Member	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Useful life	'3 years 0 months 0 days	'	'
Software [Member] | Maximum Member	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Useful life	'5 years 0 months 0 days	'	'
Software [Member] | Minimum Member	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Useful life	'3 years 0 months 0 days	'	'
Minnesota Life [Member] | Value Of Business Acquired [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Intangible Assets, Useful Life	'30 years 0 months 0 days	'	'
TIAA [Member] | Value Of Business Acquired [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Intangible Assets, Useful Life	'20 years 0 months 0 days	'	'
Group Insurance [Member] | Deferred Acquisition Costs [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Intangible Assets, Useful Life	'2 years 6 months 0 days	'	'
Individual Disability Insurance Policies [Member] | Deferred Acquisition Costs [Member] | Maximum Member	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Intangible Assets, Useful Life	'25 years 0 months 0 days	'	'
Individual Disability Insurance Policies [Member] | Deferred Acquisition Costs [Member] | Minimum Member	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Intangible Assets, Useful Life	'20 years 0 months 0 days	'	'
Individual Disability Insurance Policies [Member] | Deferred Acquisition Costs [Member] | Year Ten [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Expected percent that investment contract to be amortized.	50.00%	'	'
Individual Disability Insurance Policies [Member] | Deferred Acquisition Costs [Member] | Year Fifteen [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Expected percent that investment contract to be amortized.	75.00%	'	'
Group Annuities [Member] | Deferred Acquisition Costs [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Intangible Assets, Useful Life	'10 years 0 months 0 days	'	'
Group Annuities [Member] | Deferred Acquisition Costs [Member] | Year Five [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Expected percent that investment contract to be amortized.	80.00%	'	'
Individual Annuities [Member] | Deferred Acquisition Costs [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Intangible Assets, Useful Life	'30 years 0 months 0 days	'	'
Individual Annuities [Member] | Deferred Acquisition Costs [Member] | Year Five [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Expected percent that investment contract to be amortized.	50.00%	'	'
Individual Annuities [Member] | Deferred Acquisition Costs [Member] | Year Fifteen [Member]	'	'	'
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]	'	'	'
Expected percent that investment contract to be amortized.	95.00%	'	'

Summary_Of_Significant_Account4

Summary Of Significant Accounting Policies (Property And Equipment And Accumulated Depreciation) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Summary Of Significant Accounting Policies [Abstract]	'	'
Home office properties	$136.90	$135.30
Office furniture and equipment	47.9	47.7
Capitalized software	169.4	160.8
Leasehold improvements	13.9	13
Property and equipment, gross	368.1	356.8
Less: accumulated depreciation	283.4	266.1
Property and equipment, net	$84.70	$90.70

Net_Income_Per_Common_Share_De

Net Income Per Common Share (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net Income Per Common Share [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Net income	$65	$59	$57.70	$46.80	$38.40	$44.90	$20	$35.20	$228.50	$138.50	$136.70
Basic weighted-average common shares outstanding	'	'	'	'	'	'	'	'	44,243,364	44,283,771	44,876,650
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Diluted weighted-average common shares outstanding	'	'	'	'	'	'	'	'	44,527,405	44,359,891	45,016,070
Net income per basic common share	$1.48	$1.33	$1.30	$1.05	$0.87	$1.02	$0.45	$0.79	$5.16	$3.13	$3.05
Net income per diluted common share	$1.46	$1.32	$1.30	$1.05	$0.87	$1.01	$0.45	$0.79	$5.13	$3.12	$3.04
Antidilutive shares not included in net income per diluted common share calculation	'	'	'	'	'	'	'	'	292,750	2,220,045	1,974,242
Employee Stock Option [Member]	'	'	'	'	'	'	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Dilutive shares from share based compensation	'	'	'	'	'	'	'	'	194,978	74,232	131,926
Stock Award Grants [Member]	'	'	'	'	'	'	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Dilutive shares from share based compensation	'	'	'	'	'	'	'	'	89,063	1,888	7,494

ShareBased_Compensation_Narrat

Share-Based Compensation (Narrative-Options) (Details) (Stock Incentive 2002 Plan [Member], USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Number of shares of common stock authorized for share based compensation arrangements	7,000,000	'	'
Number of shares of common stock available for grant	2,856,251	'	'
Employee Stock Option [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Award vesting period	'4 years 0 months 0 days	'	'
Duration from change in control	'0 years 24 months 0 days	'	'
Stock option awards expiration period (in years)	'10 years 0 months 0 days	'	'
Compensation cost related to unvested option, not recognized	$5,400,000	'	'
Weighted average recognition period of unrecognized compensation cost for stock options	'2 years 4 months 24 days	'	'
Weighted average grant date fair value of options granted	$16.15	$13.73	$16.87
Total intrinsic value of the options exercised	14,400,000	3,200,000	1,800,000
Amount received from the exercise of stock options	50,200,000	7,600,000	3,500,000
Tax benefit derived from the tax deduction received for the difference between market price of common stock and the exercise price of options exercised	3,600,000	1,100,000	600,000
Director Stock Options [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Non-employee director annual compensation in stock options granted, fair value	$50,000	'	'

Share_Based_Comensation_Narrat

Share Based Comensation (Narrative-Stock Awards) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Performance Period Year 3 [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Target payout percentage of the maximum performance-based stock awards	50.00%	'	'
Stock Incentive 2002 Plan [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	7,000,000	'	'
Shares available issuance as stock award grants	2,856,251	'	'
Stock Incentive 2002 Plan [Member] | Stock Award Grants [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	1,700,000	'	'
Shares available issuance as stock award grants	1,074,257	'	'
Stock Incentive 2002 Plan [Member] | Performance Shares Member	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Award vesting period	'3 years 0 months 0 days	'	'
Issued under share-based compensation plans net, shares	0	9,899	4,906
Additional compensation cost assuming maximum payout of outstanding performance-based stock awards	$9,500,000	'	'
Additional compensation cost assuming a target payout of outstanding performance-based stock awards	3,500,000	'	'
Stock Awards weighted average recognition period of additional compensation cost assuming a target payout, years	'1 year 4 months 24 days	'	'
Stock Incentive 2002 Plan [Member] | Performance Period Year 2 [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Target payout percentage of the maximum performance-based stock awards	50.00%	'	'
Stock Incentive 2002 Plan [Member] | RSUs Member	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Award vesting period	'3 years 0 months 0 days	'	'
Share Based Compensation Arrangement By Share Based Payment Award Options Total Compensation Cost Not Yet Recognized	1,400,000	'	'
Share Based Compensation Arrangement By Share Based Payment Award OptionsTotalCompensation Cost Not Yet Recognized Weighted Average Period	'2 years 0 months 0 days	'	'
Stock Incentive 2002 Plan [Member] | Director Stock Grants [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Issued under share-based compensation plans net, shares	20,099	9,489	10,399
Weighted average fair value of shares issued for vested stock grants	$44.12	36.4	43
Non-employee director annual compensation in common stock, fair value	$100,000	50,000	'

Share_Based_Compensation_Narra

Share Based Compensation (Narratvie-ESPP) (Details) (USD $)	Dec. 31, 2013
Employee Stock Purchase 1999 Plan [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	3,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	1,425,002
Discount rate for employee stock purchase plan	15.00%
Employee share purchase plan offering period, months	'0 years 6 months 0 days
Maximum employee gross compensation withheld to purchase common stock	10.00%
Maximum fair value of common stock purchased by employee each calendar year	$25,000
Amended Employee Stock Purchase 1999 Plan [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Discount rate for employee stock purchase plan	5.00%
Employee share purchase plan offering period, months	'0 years 6 months 0 days
Maximum employee gross compensation withheld to purchase common stock	5.00%
Maximum fair value of common stock purchased by employee each calendar year	25,000
Maxium dollar contribution to ESPP	$5,000

ShareBased_Compensation_Schedu

Share-Based Compensation (Schedule Of Compensation Cost And Related Income Tax Benefit Under Share-Based Compensation Plans) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-Based Compensation [Abstract]	'	'	'
Compensation cost	$8.30	$6.70	$5.90
Related income tax benefit	$2.90	$2.30	$2.10

ShareBased_Compensation_Summar

Share-Based Compensation (Summary Of Option Activity And Options Outstanding And Exercisable) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Share-Based Compensation [Abstract]	'		'		'		'
Options, Outstanding, beginning balance	2,704,168		2,784,361		2,680,493		'
Options, Granted	211,367		268,033		272,785		'
Options, Exercised	-1,214,399		-294,226		-120,880		'
Options, Forfeited	-31,211		-16,300		-42,837		'
Options, Expired	-14,831		-37,700		-5,200		'
Options, Outstanding, ending balance	1,655,094		2,704,168		2,784,361		2,680,493
Vested or expected to be vested	1,636,282		'		'		'
Fully vested and exercisable	1,278,866		'		'		'
Weighted-Average Exercise Price, Outstanding, beginning of period	$42.17		$40.84		$40.01		'
Weighted-Average Exercise Price, Granted	$44.27		$38.09		$44.18		'
Weighted-Average Exercise Price, Exercised	$41.37		$25.67		$29.10		'
Weighted-Average Exercise Price, Forfeited	$47.13		$39.56		$42.78		'
Weighted-Average Exercise Price, Expired	$40.34		$45.06		$42.73		'
Weighted-Average Exercise Price, Outstanding, end of period	$43.02		$42.17		$40.84		$40.01
Weighted-Average Exercise Price, Vested or expected to be vested	$43.02		'		'		'
Weighted-Average Exercise Price, Fully vested and exercisable	$43.24		'		'		'
Weighted-Average Remaining Contractual Terms (Years)	'5 years 7 months 6 days		'4 years 6 months 0 days		'5 years 1 month 6 days		'5 years 7 months 6 days
Weighted-Average Remaining Contractual Terms (Years), Vested or expected to be vested	'5 years 6 months 0 days		'		'		'
Weighted-Average Remaining Contractual Terms (Years), Exercisable	'4 years 8 months 12 days		'		'		'
Total Intrinsic Value, Outstanding, beginning of period	$2,887,006	[1]	$5,947,355	[1]	$17,226,460	[1]	'
Total Intrinsic Value, Outstanding, end of period	38,455,709	[1]	2,887,006	[1]	5,947,355	[1]	17,226,460	[1]
Total Intrinsic Value, Vested or expected to be vested	38,004,455.96	[1]	'		'		'
Total Intrinsic Value, Fully vested and exercisable	$29,430,648	[1]	'		'		'
[1]	The intrinsic value of outstanding options can fluctuate significantly due to changes in the year end closing stock price from year to year.

ShareBased_Compensation_Weight

Share-Based Compensation (Weighted-Average Assumptions Used To Determine Fair Value Of Option Grants) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-Based Compensation [Abstract]	'	'	'
Dividend yield	2.25%	2.36%	1.97%
Expected stock price volatility	45.86%	47.30%	46.24%
Risk-free interest rate	1.31%	1.02%	2.35%
Expected option lives	'6 years 2 months 12 days	'5 years 10 months 24 days	'5 years 8 months 12 days

ShareBased_Compensation_Summar1

Share-Based Compensation (Summary Of Activity Of Performance Shares Outstanding) (Details) (Performance Shares Member, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Performance Shares Member	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Unvested balance, Beginning of period	296,796	190,968	127,658
Granted	129,172	179,818	116,978
Vested	-13,964	-9,200	-6,504
Forfeited	-114,722	-64,790	-47,164
Unvested balance, Ending	297,282	296,796	190,968
Unvested balance, Weighted-Average Grant Date Fair Value, beginning of period	$43.14	$44.05	$34.99
Unvested balance, Weighted-Average Grant Date Fair Value, end of period	$40.34	$43.14	$44.05

ShareBased_Compensation_Assump

Share-Based Compensation (Assumptions Used To Determine The Fair Value Of ESPP Embedded Option) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]	'	'	'
Expected option lives	'6 years 2 months 12 days	'5 years 10 months 24 days	'5 years 8 months 12 days
Employee Stock Purchase 1999 Plan [Member]	'	'	'
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]	'	'	'
Dividend yield, minimum	1.69%	2.38%	1.85%
Dividend yield, maximum	2.44%	3.06%	2.11%
Expected stock price volatility, minimum	17.43%	27.80%	22.03%
Expected stock price volatility, maximum	17.58%	49.09%	25.63%
Risk-free interest rate, minimum	0.07%	0.06%	0.10%
Risk-free interest rate, maximum	0.11%	0.13%	0.18%
Expected option lives	'0 years 6 months 0 days	'0 years 6 months 0 days	'0 years 6 months 0 days

ShareBased_Compensation_Schedu1

Share-Based Compensation (Schedule Of Compensation Cost And Related Income Tax Benefit Under Employee Stock Purchase Plan) (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Compensation cost	$8.30	$6.70	$5.90
Related income tax benefit	2.9	2.3	2.1
Employee Stock Purchase 1999 Plan [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted-average fair value per share for the Company's ESPP offerings	$4.16	$9.02	$9.46
Compensation cost	0.3	1.4	1.2
Related income tax benefit	$0.10	$0.50	$0.40

Retirement_Benefits_Narrative_

Retirement Benefits (Narrative) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Pension [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Estimated net (income) loss will be amortized from accumulated other comprehensive loss into net periodic benefit cost	($0.20)	'	'
Estimated prior service cost (credit) will be amortized from accumulated other comprehensive loss into net periodic benefit cost	-0.4	'	'
Employer contributions to pension plans	0	10	58
Expected contributions to defined benefit plans in the upcoming year	0	'	'
Employee pension plan held in StanCorp equity securities as plan assets	0	'	'
Plan assets expected to be returned	'None	'	'
Other Postretirement Benefit Plans Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Estimated net (income) loss will be amortized from accumulated other comprehensive loss into net periodic benefit cost	0	'	'
Estimated prior service cost (credit) will be amortized from accumulated other comprehensive loss into net periodic benefit cost	0	'	'
Employer contributions to pension plans	0.7	0.3	0.3
Employer contributions for medical costs	0.4	0.3	0.3
Expected contributions to defined benefit plans in the upcoming year	0.6	'	'
Projected discounted cash flow obligation for postretirement benefit plan	17.6	24	'
Plan assets expected to be returned	'None	'	'
Supplemental Employee Retirement Plan Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Expenses towards non-qualified supplemental retirement plan	3.1	1.9	2.5
Other liabilities for non-qualified plan	31.1	27.5	'
Accumulated other comprehensive loss net of tax	5.7	4.7	5.7
Deferred Compensation Plans [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Employer contributions to the deferred compensation plans	9.9	9.9	10.3
Liability for the plans, unfunded portion	$11.60	$10.50	'

Retirement_Benefits_Reconcilia

Retirement Benefits (Reconciliation Of Changes In Pension Plans' Projected Benefit Obligations, Fair Value Of Plan Assets And Funded Status) (Details) (Defined Benefit Pension [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Pension [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Benefit obligation at beginning of the year	($418.50)	($371.60)	($323.70)
Service cost	-10.2	-9.7	-9.2
Interest cost	-16.7	-16.5	-17.5
Actuarial loss	26	-29.7	-29
Benefits Paid	11	9	7.8
Benefit obligation at end of the year	-408.4	-418.5	-371.6
Fair value of plan assets at beginning of the year	386	349.7	292.6
Actual return on plan assets	65.4	35.4	7
Employer contributions	0	10	58
Benefits paid and estimated expenses	-11	-9.1	-7.9
Fair value of plan assets at end of the year	440.4	386	349.7
Funded status at end of the year	$32	($32.50)	($21.90)

Retirement_Benefits_Projected_

Retirement Benefits (Projected And Accumulated Benefit Obligations And Fair Value Of Plan Assets For Pension Plans) (Details) (Defined Benefit Pension [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Defined Benefit Pension [Member]	'	'	'	'
Projected benefit obligation	$408.40	$418.50	$371.60	$323.70
Accumulated benefit obligation	374.2	386.5	337.5	'
Fair value of plan assets	$440.40	$386	$349.70	$292.60

Retirement_Benefits_Amounts_Re

Retirement Benefits (Amounts Recognized In Accumulated Other Comprehensive Loss) (Details) (Defined Benefit Pension [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Defined Benefit Pension [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Net Loss	$31.40	$78.30	$70.10
Prior service cost	2.3	2.7	3.1
Total recognized in accumulated other comprehensive loss	$33.70	$81	$73.20

Retirement_Benefits_Components

Retirement Benefits (Components Of Net Periodic Benefit Cost, Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive (Income) Loss And Assumptions Used In Measurements (Details) (Defined Benefit Pension [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Pension [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	$10.30	$9.80	$9.30
Interest cost, net periodic benefit	16.7	16.5	17.5
Expected return on plan assets	-29.3	-26.5	-22.1
Amortization of prior service cost	0.6	0.6	0.6
Amortization of net actuarial loss	9.9	8.3	4
Net periodic benefit cost	8.2	8.7	9.3
Net loss	-62.2	20.9	44.1
Prior service cost	0	0	0
Amortization of prior service cost	-0.6	-0.6	-0.6
Amortization of net actuarial loss	-9.9	-8.3	-4
Total recognized in other comprehensive income	-72.7	12	39.5
Total recognized in net periodic benefit cost and other comprehensive income	($64.50)	$20.70	$48.80
Assumptions used for net periodic benefit cost, Discount rate	4.00%	4.50%	5.50%
Assumptions used for net periodic benefit cost, Expected return on plan assets	7.70%	7.69%	7.68%
Assumptions used for net periodic benefit cost, Rate of compensation increase	3.00%	3.25%	4.50%
Assumptions used to determine benefit obligations, Discount rate	4.75%	4.00%	4.50%
Assumptions used to determine benefit obligations, Rate of compensation increase	3.50%	3.00%	3.25%

Retirement_Benefits_Expected_B

Retirement Benefits (Expected Benefit Payments For Pension Plans) (Details) (Defined Benefit Pension [Member], USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Defined Benefit Pension [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	$11.80
2015	13
2016	14.3
2017	15.6
2018	17
2019-2023	$105.40

Retirement_Benefits_Target_And

Retirement Benefits (Target And Actual Weighted-Average Asset Allocations For Pension Plans) (Details) (Defined Benefit Pension [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]	'	'
Target asset allocation	100.00%	'
Actual asset allocation	100.00%	100.00%
Equity Securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Target asset allocation	50.00%	'
Actual asset allocation	49.00%	48.90%
Debt Securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Target asset allocation	50.00%	'
Actual asset allocation	51.00%	51.10%

Retirement_Benefits_Estimated_

Retirement Benefits (Estimated FV Of Assets And Liabilities Measured And Recorded At FV On A Recurring Basis Defined Pension) (Details) (Defined Benefit Pension [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	$440.40	$386	$349.70	$292.60
Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	215.9	188.8	'	'
Fair Value Inputs Level1 [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	215.9	188.8	'	'
Fair Value Inputs Level1 [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	215.9	188.8	'	'
Fair Value Inputs Level2 [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	224.5	197.2	'	'
Pooled Separate Account Funds Large Cap Growth [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	43	-39.3	'	'
Pooled Separate Account Funds Large Cap Growth [Member] | Fair Value Inputs Level1 [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	43	-39.3	'	'
Pooled Separate Account Funds Large Cap Blend [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	64.7	57.5	'	'
Pooled Separate Account Funds Large Cap Blend [Member] | Fair Value Inputs Level1 [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	64.7	57.5	'	'
Pooled Separate Account Funds Large Cap Value [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	21.7	19.3	'	'
Pooled Separate Account Funds Large Cap Value [Member] | Fair Value Inputs Level1 [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	21.7	19.3	'	'
Pooled Separate Account Funds Mid Cap Blend [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	64.8	54.7	'	'
Pooled Separate Account Funds Mid Cap Blend [Member] | Fair Value Inputs Level1 [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	64.8	54.7	'	'
Pooled Separate Account Funds Foreign [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	21.7	18	'	'
Pooled Separate Account Funds Foreign [Member] | Fair Value Inputs Level1 [Member] | Equity Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	21.7	18	'	'
Stable Asset Fund [Member] | Debt Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	224.5	197.2	'	'
Stable Asset Fund [Member] | Fair Value Inputs Level2 [Member] | Debt Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	$224.50	$197.20	'	'

Retirement_Benefits_Reconcilia1

Retirement Benefits (Reconciliation Of Changes In Postretirement Benefit Plans' Accumulated Benefit Obligations, Fair Value Of Plan Assets And Funded Status) (Details) (Other Postretirement Benefit Plans Defined Benefit [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other Postretirement Benefit Plans Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Benefit obligation at beginning of the year	($23.90)	($41)	($40.50)
Service cost	0	-1	-1.5
Interest cost	-1.1	-1.8	-2.1
Plan amendments	0.8	25.2	8
Actuarial loss	5.2	-5.9	-5.4
Benefits Paid	1.4	0.6	0.5
Benefit obligation at end of the year	-17.6	-23.9	-41
Fair value of plan assets at beginning of the year	21.6	20.7	18.2
Actual return on plan assets	-1.6	1.2	2.7
Employer contributions	0.7	0.3	0.3
Benefits paid and estimated expenses	-1.4	-0.6	-0.5
Fair value of plan assets at end of the year	19.3	21.6	20.7
Funded status at end of the year	$1.70	($2.30)	($20.30)

Retirement_Benefits_Amounts_Re1

Retirement Benefits (Amounts Recognized In Accumulated Other Comprehensive (Income) Loss) (Details) (Other Postretirement Benefit Plans Defined Benefit [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Other Postretirement Benefit Plans Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Net Loss	($1)	$5.10	$2.20
Prior service cost	0	-17.1	-1
Total recognized in accumulated other comprehensive loss	($1)	($12)	$1.20

Retirement_Benefits_Assumed_He

Retirement Benefits (Assumed Health Care Cost Trend Rates For Next Year) (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Assumed Health Care Cost Trend Rates For Next Year [Line Items]	'	'
Rate to which the cost trend is assumed to decline (the ultimate trend rate)	4.50%	4.50%
Medical [Member]	'	'
Assumed Health Care Cost Trend Rates For Next Year [Line Items]	'	'
Assumed health care cost trend rates for next year	7.10%	7.30%
Prescriptions [Member]	'	'
Assumed Health Care Cost Trend Rates For Next Year [Line Items]	'	'
Assumed health care cost trend rates for next year	7.50%	7.80%
Health Maintenance Organization [Member]	'	'
Assumed Health Care Cost Trend Rates For Next Year [Line Items]	'	'
Assumed health care cost trend rates for next year	6.00%	6.40%

Retirement_Benefits_OnePercent

Retirement Benefits (One-Percentage-Point Change In Assumed Health Care Cost Trend Rates) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Retirement Benefits [Abstract]	'
Effect on total of service and interest cost, 1% Point Increase	$0.10
Effect on postretirement benefit obligation, 1% Point Increase	1.5
Effect on total of service and interest cost, 1% Point Decrease	-0.1
Effect on postretirement benefit obligation, 1% Point Decrease	($1.30)

Retirement_Benefits_Components1

Retirement Benefits (Components Of Net Periodic Benefit Cost, Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Loss And Assumptions Used In Measurement Of Postretirement Benefits) (Details) (Other Postretirement Benefit Plans Defined Benefit [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Other Postretirement Benefit Plans Defined Benefit [Member]	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'
Service cost	$0	$1	$1.50
Interest cost, net periodic benefit	1	1.8	2.1
Expected return on plan assets	-0.8	-0.8	-0.8
Amortization of prior service cost	-26.3	-0.4	-0.3
Amortization of net actuarial loss	5.7	0	0.1
Curtailment loss	0	0	0.7
Net periodic benefit cost	-20.4	1.6	3.3
Net loss	-3.3	5.5	6.1
Prior service cost	0	-25.2	0
Amortization of prior service cost	26.3	0.4	0.2
Amortization of net actuarial loss	-5.8	0	-0.1
Total recognized in other comprehensive income	17.2	-19.3	6.2
Total recognized in net periodic benefit cost and other comprehensive income	($3.20)	($17.70)	$9.50
Assumptions used for net periodic benefit cost, Discount rate	4.00%	4.50%	5.50%
Assumptions used for net periodic benefit cost, Expected return on plan assets	4.20%	4.20%	4.50%
Assumptions used for net periodic benefit cost, Rate of compensation increase graded by age	'	'	5.00%
Assumptions used to determine benefit obligations, Discount rate	4.80%	4.00%	4.50%

Retirement_Benefits_Expected_B1

Retirement Benefits (Expected Benefit Payments For Postretirement Benefit Plan) (Details) (Other Postretirement Benefit Plans Defined Benefit [Member], USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Other Postretirement Benefit Plans Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
2014	$1.30
2015	1.3
2016	1.3
2017	1.2
2018	1.2
2019-2023	$5.60

Retirement_Benefits_Target_And1

Retirement Benefits (Target And Actual Weighted-Average Asset Allocations For Postretirement Medical Plan) (Details) (Other Postretirement Benefit Plans Defined Benefit [Member])	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]	'	'
Target asset allocation	100.00%	'
Actual asset allocation	100.00%	100.00%
Debt Securities [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Target asset allocation	95.00%	'
Actual asset allocation	96.20%	92.60%
Cash And Cash Equivalents [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Target asset allocation	5.00%	'
Actual asset allocation	3.80%	7.40%

Retirement_Benefits_Estimated_1

Retirement Benefits (Estimated FV Of Assets And Liabilities Measured And Recorded At FV On A Recurring Basis Postretirement) (Details) (Other Postretirement Benefit Plans Defined Benefit [Member], USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	$19.30	$21.60	$20.70	$18.20
Municipal Bonds [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	16.8	19	'	'
Corporate Debt Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	1.8	1	'	'
Cash And Cash Equivalents [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	0.7	1.6	'	'
Fair Value Inputs Level1 [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	0.7	1.6	'	'
Fair Value Inputs Level1 [Member] | Cash And Cash Equivalents [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	0.7	1.6	'	'
Fair Value Inputs Level2 [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	18.6	20	'	'
Fair Value Inputs Level2 [Member] | Municipal Bonds [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	16.8	19	'	'
Fair Value Inputs Level2 [Member] | Corporate Debt Securities [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Total pension plan assets are recorded at fair value	$1.80	$1	'	'

Segments_Intersegment_Administ

Segments (Intersegment Administrative Fee Revenues) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Intersegment Revenues [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Intersegment administrative fee revenues	$32	$30.50	$30.40	$28.70	$28.50	$27.80	$29.80	$28.60	$121.60	$114.70	$115.50
Intersegment [Member]	'	'	'	'	'	'	'	'	'	'	'
Intersegment Revenues [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Intersegment administrative fee revenues	'	'	'	'	'	'	'	'	$18.60	$17.90	$16.70

Segments_Premiums_Administrati

Segments (Premiums, Administrative Fee And Net Investment Income By Major Product Line Or Category) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	$528.60	$524.40	$535.10	$536.20	$533.80	$528.70	$548.10	$553.30	$2,124.30	$2,163.90	$2,153.30
Administrative fees	32	30.5	30.4	28.7	28.5	27.8	29.8	28.6	121.6	114.7	115.5
Net investment income	160.8	155.8	154.1	159.2	157.6	159.8	151.4	159.7	629.9	628.5	612.8
Insurance Services [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	2,117.40	2,157.20	2,145.30
Administrative fees	'	'	'	'	'	'	'	'	15.3	13.9	12.3
Net investment income	'	'	'	'	'	'	'	'	320.6	339.7	341.3
Individual Disability [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	190.5	176.6	172.3
Administrative fees	'	'	'	'	'	'	'	'	0.2	0.2	0.3
Net investment income	'	'	'	'	'	'	'	'	52.8	53.7	52.7
Employee Benefits [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	1,926.90	1,980.60	1,973
Administrative fees	'	'	'	'	'	'	'	'	15.1	13.7	12
Net investment income	'	'	'	'	'	'	'	'	267.8	286	288.6
Employee Benefits [Member] | Group Life And Add [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	849.7	883.7	892.6
Employee Benefits [Member] | Group Long Term Disability [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	783	801.4	803.3
Employee Benefits [Member] | Group Short Term Disability [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	229	212.6	208
Employee Benefits [Member] | Group Other [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	78.3	78.9	81.6
Employee Benefits [Member] | Experience Rated Refunds [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	-13.1	4	-12.5
Asset Management Segment [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	6.9	6.7	8
Administrative fees	'	'	'	'	'	'	'	'	124.9	118.8	119.9
Net investment income	'	'	'	'	'	'	'	'	293.2	278.6	262.7
Asset Management Segment [Member] | Retirement Plans [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	2.2	1.9	2
Administrative fees	'	'	'	'	'	'	'	'	93.3	88	90
Net investment income	'	'	'	'	'	'	'	'	103.2	94.9	90.4
Asset Management Segment [Member] | Individual Annuities [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	4.7	4.8	6
Net investment income	'	'	'	'	'	'	'	'	177.2	170.6	161
Asset Management Segment [Member] | Other Financial Services Businesses [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Administrative fees	'	'	'	'	'	'	'	'	31.6	30.8	29.9
Net investment income	'	'	'	'	'	'	'	'	12.8	13.1	11.3
Other Category [Member]	'	'	'	'	'	'	'	'	'	'	'
Total Revenue By Segment And Product Line [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Administrative fees	'	'	'	'	'	'	'	'	-18.6	-18	-16.7
Net investment income	'	'	'	'	'	'	'	'	$16.10	$10.20	$8.80

Segments_PTOI_and_Assets_Addit

Segments (PTOI and Assets Additional Information) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'
Income Before Income Taxes	$313	$183.40	$191.50
Total Assets	21,393.30	19,791.30	18,403.20
Insurance Services [Member]	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'
Income Before Income Taxes	272.4	179.8	201.2
Total Assets	8,088.10	8,250.80	8,204.80
Employee Benefits [Member]	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'
Income Before Income Taxes	216.4	129.8	155.9
Total Assets	5,744.70	5,991.40	6,002.90
Individual Disability [Member]	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'
Income Before Income Taxes	56	50	45.3
Total Assets	2,343.40	2,259.40	2,201.90
Asset Management Segment [Member]	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'
Income Before Income Taxes	79.3	64	61.3
Total Assets	12,777.10	11,046	9,922.90
Other Category [Member]	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'
Income Before Income Taxes	-38.7	-60.4	-71
Total Assets	$528.10	$494.50	$275.50

Segments_Segment_Information_D

Segments (Segment Information) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	$528.60	$524.40	$535.10	$536.20	$533.80	$528.70	$548.10	$553.30	$2,124.30	$2,163.90	$2,153.30
Administrative fees	32	30.5	30.4	28.7	28.5	27.8	29.8	28.6	121.6	114.7	115.5
Net investment income	160.8	155.8	154.1	159.2	157.6	159.8	151.4	159.7	629.9	628.5	612.8
Net capital losses	-2.8	-8.7	-2.6	-1.6	-1.9	-2.6	-4	-0.2	-15.7	-8.7	-6.9
Total revenues	718.6	702	717	722.5	718	713.7	725.3	741.4	2,860.10	2,898.40	2,874.70
Benefits to policyholders	394.5	395	424.1	441.8	444.7	422.4	475.9	450	1,655.40	1,793	1,771.20
Interest credited	'	'	'	'	'	'	'	'	176.4	171.3	161
Operating expenses	'	'	'	'	'	'	'	'	442.6	470.5	471.2
Commissions and bonuses	'	'	'	'	'	'	'	'	207.9	203.7	218.7
Premium taxes	'	'	'	'	'	'	'	'	35.3	37.5	36.7
Interest expense	'	'	'	'	'	'	'	'	34.4	39.9	38.9
Net increase in deferred acquisition costs, value of business acquired and other intangible assets	'	'	'	'	'	'	'	'	-4.9	-0.9	-14.5
Total benefits and expenses	'	'	'	'	'	'	'	'	2,547.10	2,715	2,683.20
Income (loss) before income taxes	'	'	'	'	'	'	'	'	313	183.4	191.5
Total assets	21,393.30	'	'	'	19,791.30	'	'	'	21,393.30	19,791.30	18,403.20
Insurance Services [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	2,117.40	2,157.20	2,145.30
Administrative fees	'	'	'	'	'	'	'	'	15.3	13.9	12.3
Net investment income	'	'	'	'	'	'	'	'	320.6	339.7	341.3
Total revenues	'	'	'	'	'	'	'	'	2,453.30	2,510.80	2,498.90
Benefits to policyholders	'	'	'	'	'	'	'	'	1,637.70	1,773.30	1,750.90
Interest credited	'	'	'	'	'	'	'	'	4.3	4.2	4.6
Operating expenses	'	'	'	'	'	'	'	'	340	349.1	338.7
Commissions and bonuses	'	'	'	'	'	'	'	'	174.2	172.7	185.1
Premium taxes	'	'	'	'	'	'	'	'	35.2	37.5	36.6
Net increase in deferred acquisition costs, value of business acquired and other intangible assets	'	'	'	'	'	'	'	'	-10.5	-5.8	-18.2
Total benefits and expenses	'	'	'	'	'	'	'	'	2,180.90	2,331	2,297.70
Income (loss) before income taxes	'	'	'	'	'	'	'	'	272.4	179.8	201.2
Total assets	8,088.10	'	'	'	8,250.80	'	'	'	8,088.10	8,250.80	8,204.80
Employee Benefits [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	1,926.90	1,980.60	1,973
Administrative fees	'	'	'	'	'	'	'	'	15.1	13.7	12
Net investment income	'	'	'	'	'	'	'	'	267.8	286	288.6
Total revenues	'	'	'	'	'	'	'	'	2,209.80	2,280.30	2,273.60
Benefits to policyholders	'	'	'	'	'	'	'	'	1,515.90	1,657.10	1,635
Interest credited	'	'	'	'	'	'	'	'	4.3	4.2	4.6
Operating expenses	'	'	'	'	'	'	'	'	313.3	323.6	312.3
Commissions and bonuses	'	'	'	'	'	'	'	'	126.7	125.1	137.1
Premium taxes	'	'	'	'	'	'	'	'	31.3	33.6	33
Net increase in deferred acquisition costs, value of business acquired and other intangible assets	'	'	'	'	'	'	'	'	1.9	6.9	-4.3
Total benefits and expenses	'	'	'	'	'	'	'	'	1,993.40	2,150.50	2,117.70
Income (loss) before income taxes	'	'	'	'	'	'	'	'	216.4	129.8	155.9
Total assets	5,744.70	'	'	'	5,991.40	'	'	'	5,744.70	5,991.40	6,002.90
Individual Disability [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	190.5	176.6	172.3
Administrative fees	'	'	'	'	'	'	'	'	0.2	0.2	0.3
Net investment income	'	'	'	'	'	'	'	'	52.8	53.7	52.7
Total revenues	'	'	'	'	'	'	'	'	243.5	230.5	225.3
Benefits to policyholders	'	'	'	'	'	'	'	'	121.8	116.2	115.9
Interest credited	'	'	'	'	'	'	'	'	'	0	0
Operating expenses	'	'	'	'	'	'	'	'	26.7	25.5	26.4
Commissions and bonuses	'	'	'	'	'	'	'	'	47.5	47.6	48
Premium taxes	'	'	'	'	'	'	'	'	3.9	3.9	3.6
Net increase in deferred acquisition costs, value of business acquired and other intangible assets	'	'	'	'	'	'	'	'	-12.4	-12.7	-13.9
Total benefits and expenses	'	'	'	'	'	'	'	'	187.5	180.5	180
Income (loss) before income taxes	'	'	'	'	'	'	'	'	56	50	45.3
Total assets	2,343.40	'	'	'	2,259.40	'	'	'	2,343.40	2,259.40	2,201.90
Asset Management Segment [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Premiums	'	'	'	'	'	'	'	'	6.9	6.7	8
Administrative fees	'	'	'	'	'	'	'	'	124.9	118.8	119.9
Net investment income	'	'	'	'	'	'	'	'	293.2	278.6	262.7
Total revenues	'	'	'	'	'	'	'	'	425	404.1	390.6
Benefits to policyholders	'	'	'	'	'	'	'	'	17.7	19.7	20.3
Interest credited	'	'	'	'	'	'	'	'	172.1	167.1	156.4
Operating expenses	'	'	'	'	'	'	'	'	116.5	117.4	115.2
Commissions and bonuses	'	'	'	'	'	'	'	'	33.7	31	33.6
Premium taxes	'	'	'	'	'	'	'	'	0.1	0	0.1
Net increase in deferred acquisition costs, value of business acquired and other intangible assets	'	'	'	'	'	'	'	'	5.6	4.9	3.7
Total benefits and expenses	'	'	'	'	'	'	'	'	345.7	340.1	329.3
Income (loss) before income taxes	'	'	'	'	'	'	'	'	79.3	64	61.3
Total assets	12,777.10	'	'	'	11,046	'	'	'	12,777.10	11,046	9,922.90
Other Category [Member]	'	'	'	'	'	'	'	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Administrative fees	'	'	'	'	'	'	'	'	-18.6	-18	-16.7
Net investment income	'	'	'	'	'	'	'	'	16.1	10.2	8.8
Net capital losses	'	'	'	'	'	'	'	'	-15.7	-8.7	-6.9
Total revenues	'	'	'	'	'	'	'	'	-18.2	-16.5	-14.8
Operating expenses	'	'	'	'	'	'	'	'	-13.9	4	17.3
Interest expense	'	'	'	'	'	'	'	'	34.4	39.9	38.9
Total benefits and expenses	'	'	'	'	'	'	'	'	20.5	43.9	56.2
Income (loss) before income taxes	'	'	'	'	'	'	'	'	-38.7	-60.4	-71
Total assets	$528.10	'	'	'	$494.50	'	'	'	$528.10	$494.50	$275.50

Parent_Holding_Company_Condens2

Parent Holding Company Condensed Financial Information (Condensed Statements Of Income) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Administrative fees	$32	$30.50	$30.40	$28.70	$28.50	$27.80	$29.80	$28.60	$121.60	$114.70	$115.50
Net investment income	160.8	155.8	154.1	159.2	157.6	159.8	151.4	159.7	629.9	628.5	612.8
Net capital losses	-2.8	-8.7	-2.6	-1.6	-1.9	-2.6	-4	-0.2	-15.7	-8.7	-6.9
Total revenues	718.6	702	717	722.5	718	713.7	725.3	741.4	2,860.10	2,898.40	2,874.70
Interest expense	'	'	'	'	'	'	'	'	34.4	39.9	38.9
Operating expenses	'	'	'	'	'	'	'	'	442.6	470.5	471.2
Total expenses	'	'	'	'	'	'	'	'	2,547.10	2,715	2,683.20
Income before income taxes	'	'	'	'	'	'	'	'	313	183.4	191.5
Income tax benefit	'	'	'	'	'	'	'	'	84.5	44.9	54.8
Net income	65	59	57.7	46.8	38.4	44.9	20	35.2	228.5	138.5	136.7
Unrealized Holding Gain (Loss) on Securities, Tax	'	'	'	'	'	'	'	'	-111.1	38.3	55.9
Other comprehensive income	'	'	'	'	'	'	'	'	-174.6	74.2	74.2
Comprehensive income	'	'	'	'	'	'	'	'	53.9	212.7	210.9
Parent Company [Member]	'	'	'	'	'	'	'	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net investment income	'	'	'	'	'	'	'	'	13.2	5	0
Net capital losses	'	'	'	'	'	'	'	'	0.2	0.1	-0.3
Total revenues	'	'	'	'	'	'	'	'	13.4	5.1	-0.3
Interest expense	'	'	'	'	'	'	'	'	34.2	39.7	38.8
Operating expenses	'	'	'	'	'	'	'	'	0.9	4.5	11.2
Total expenses	'	'	'	'	'	'	'	'	35.1	44.2	50
Income before income taxes	'	'	'	'	'	'	'	'	-21.7	-39.1	-50.3
Income tax benefit	'	'	'	'	'	'	'	'	-7.7	-14.2	-10.8
Equity in net income of subsidiaries	'	'	'	'	'	'	'	'	242.5	163.4	176.2
Net income	'	'	'	'	'	'	'	'	228.5	138.5	136.7
Other comprehensive income	'	'	'	'	'	'	'	'	47	1.7	0
SubsidiariesMember	'	'	'	'	'	'	'	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Other comprehensive income	'	'	'	'	'	'	'	'	($221.60)	$72.50	$74.20

Parent_Holding_Company_Condens3

Parent Holding Company Condensed Financial Information (Condensed Balance Sheets) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Cash and cash equivalents	$379.30	$160.70	$138.40	$152
Other assets	127.9	69.3	'	'
Total assets	21,393.30	19,791.30	18,403.20	'
Short-term debt	1.5	1	'	'
Long-term debt	551.9	551.4	'	'
Other liabilities	330.7	393.2	'	'
Total liabilities	19,240.50	17,622.30	'	'
Total shareholders' equity	2,152.80	2,169	1,990.40	1,894.60
Total liabilities and shareholders' equity	21,393.30	19,791.30	'	'
Parent Company [Member]	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Cash and cash equivalents	125.2	39.7	34.5	44.1
Investment in subsidiaries	2,252.90	2,352.50	'	'
Receivable from subsidiaries	1.5	1.2	'	'
Notes Receivable, Affiliates	250	250	'	'
Other assets	80.3	114.3	'	'
Total assets	2,709.90	2,757.70	'	'
Long-term debt	550	550	'	'
Other liabilities	7.1	38.7	'	'
Total liabilities	557.1	588.7	'	'
Total shareholders' equity	2,152.80	2,169	'	'
Total liabilities and shareholders' equity	$2,709.90	$2,757.70	'	'

Parent_Holding_Company_Condens4

Parent Holding Company Condensed Financial Information (Condensed Statements Of Cash Flows) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating:	'	'	'
Net income	$228.50	$138.50	$136.70
Other, net	-29.4	51.4	-80.6
Net cash provided by operating activities	279.6	375.7	254.1
Investing:	'	'	'
Net cash used in investing activities	-504.3	-763	-595.4
Financing:	'	'	'
Repayment of senior debt	0	250	0
Issuance of debt, net of issuance costs	0	246.7	0
Dividends paid on common stock	-48.5	-41.3	-39.3
Net cash provided by financing activities	443.3	409.6	327.7
(Decrease) increase in cash and cash equivalents	218.6	22.3	-13.6
Cash and cash equivalents, beginning of period	160.7	138.4	152
Cash and cash equivalents, end of period	379.3	160.7	138.4
Parent Company [Member]	'	'	'
Operating:	'	'	'
Net income	228.5	138.5	136.7
Equity in net income of subsidiaries	-242.5	-163.4	-176.2
Dividends received from subsidiaries	147	328.7	94.3
Other, net	23.7	-2.5	-24.5
Net cash provided by operating activities	156.7	301.3	30.3
Investing:	'	'	'
Capital contributions to subsidiaries	-0.7	-14.5	-9
Return of capital from subsidiaries	7.8	7.3	76.1
Surplus note receivable from subsidiary	0	-250	0
Receivables from subsidiaries	-0.3	3.4	13.3
Investment securities and other	0.2	1.4	0.3
Net cash used in investing activities	7	-252.4	80.7
Financing:	'	'	'
Issuance and repurchase of common stock, net	-29.7	0.9	-81.3
Repayment of senior debt	0	250	0
Issuance of debt, net of issuance costs	0	246.7	0
Dividends paid on common stock	-48.5	-41.3	-39.3
Net cash provided by financing activities	-78.2	-43.7	-120.6
(Decrease) increase in cash and cash equivalents	85.5	5.2	-9.6
Cash and cash equivalents, beginning of period	39.7	34.5	44.1
Cash and cash equivalents, end of period	$125.20	$39.70	$34.50

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2011	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]	'	'	'
Federal corporate tax rate	35.00%	'	'
Carrying forward net operating losses	$58	'	'
Deferred tax assets, valuation allowance	9.5	4.2	3.1
Tax years open for examination	'the Company is subject to examination by the IRS for the years 2009 through 2013	'	'
Maximum Member	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Unutilized NOLs expiration date	31-Dec-32	'	'
Minimum Member	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Unutilized NOLs expiration date	31-Dec-23	'	'
State and municipalities [Member]	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Carrying forward a deferred tax asset	11	'	'
State and municipalities [Member] | Maximum Member	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Unutilized NOLs expiration date	31-Dec-32	'	'
Prior Business Combinations [Member]	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Carrying forward net operating losses	$53	'	'
Prior Business Combinations [Member] | Maximum Member	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Unutilized NOLs expiration date	31-Dec-24	'	'
Prior Business Combinations [Member] | Minimum Member	'	'	'
Operating Loss Carryforwards [Line Items]	'	'	'
Unutilized NOLs expiration date	31-Dec-19	'	'

Income_Taxes_Provision_For_Inc

Income Taxes (Provision For Income Taxes) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes Disclosure [Abstract]	'	'	'
Current	$71.10	$38.50	$40.50
Deferred	13.4	6.4	14.3
Total income tax provision	$84.50	$44.90	$54.80

Income_Taxes_Reconciliation_Be

Income Taxes (Reconciliation Between Taxes Calculated Federal Corporate Tax On Income Before Income Taxes And Recorded Income Tax Provision) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes Disclosure [Abstract]	'	'	'
Tax at federal corporate rate of 35%	$109.60	$64.20	$67
(Decrease) increase in rate resulting from Tax exempt interest	'	-0.1	-0.1
(Decrease) Increase in rate resulting from Dividends received deduction	-3.6	-3.6	-3.1
(Decrease) Increase in rate resulting from State income taxes, net of federal benefit	1.3	0.2	-0.1
(Decrease) Increase in rate resulting from Federal tax credits	-24.9	-17.4	-8.6
(Decrease) increase in rate resulting from Other	2.1	1.6	-0.3
Total income tax provision	$84.50	$44.90	$54.80

Income_Taxes_Net_Deferred_Tax_

Income Taxes (Net Deferred Tax Liability) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Income Taxes Disclosure [Abstract]	'	'	'
Policyholder liabilities	$1.20	$1.80	$9.30
Compensation and benefit plans	12.6	44	42.4
Loss carryforwards	49.7	51.7	56.2
Investments	45.6	35.8	41.4
Other	3.5	2.2	1.9
Total deferred tax assets	112.6	135.5	151.2
Less: valuation allowances	-9.5	-3.1	-4.2
Net deferred tax assets	103.1	132.4	147
Net unrealized capital gains	95.7	210	173.9
Capitalized software	6.8	8.3	10.2
Deferred policy acquisition costs	63.5	59.7	61.6
Intangible assets	0.9	2	3.2
Other	0.9	0.5	1.1
Total deferred tax liabilities	167.8	280.5	250
Net deferred tax liability	($64.70)	($148.10)	($103)

Goodwill_Details

Goodwill (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Goodwill [Abstract]	'	'
Goodwill	$36	$36

Fair_Value_Narrative_Details

Fair Value (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value Measurement [Line Items]	'	'
Impact on interest credited during the period due to changes in Level 3 actuarial assumptions	$4.10	$3.30
Impaired recorded investment, with related allowance	87.7	74.1
Total assets measured on a nonrecurring basis during the period and still held as of the balance sheet date	103.9	102.1
Specific commercial mortgage loan loss allowance	25.9	25.6
Real Estate Owned [Member]	'	'
Fair Value Measurement [Line Items]	'	'
Capital losses recorded during the period on real estate owned measured on a nonrecurring basis and still held	7.2	2.1
Total assets measured on a nonrecurring basis during the period and still held as of the balance sheet date	35.2	48.2
Commercial Mortgage Loans [Member]	'	'
Fair Value Measurement [Line Items]	'	'
Total assets measured on a nonrecurring basis during the period and still held as of the balance sheet date	$68.70	$53.90

Fair_Value_Estimated_Fair_Valu

Fair Value (Estimated Fair Value And The Carrying Value Of Each Financial Instrument) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Total fixed maturity securities-available-for-sale, Fair Value	$7,120.50	$7,190.70
Commercial mortgage loans, net	5,405.10	5,267.40
Separate account assets	6,393.20	5,154.30
Other policyholder funds	6,051.60	5,531.10
Short-term debt	1.5	1
Long-term debt	551.9	551.4
Carrying (Reported) Amount, Fair Value Disclosure [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	7,120.50	7,190.70
Commercial mortgage loans, net	5,405.10	5,267.40
Policy loans	2.5	2.5
Separate account assets	6,393.20	5,154.30
Short-term debt	1.5	1
Long-term debt	551.9	551.4
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U S Government Agencies Debt Securities [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	353.2	413
Carrying (Reported) Amount, Fair Value Disclosure [Member] | U S States And Political Subdivisions [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	140.3	168.4
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Foreign Government Debt [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	65.5	72.1
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Corporate Bond Securities [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	6,545.70	6,525.90
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Investment Type Contracts [Member]	'	'
Other policyholder funds	5,469.80	4,916.70
Carrying (Reported) Amount, Fair Value Disclosure [Member] | S And P Five Hundred Index Options [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	15.8	11.3
Carrying (Reported) Amount, Fair Value Disclosure [Member] | Index Based Interest Guarantees [Member]	'	'
Index-based interest guarantees	67.6	57.4
Estimate Of Fair Value Fair Value Disclosure [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	7,120.50	7,190.70
Commercial mortgage loans, net	5,769.60	5,946.30
Policy loans	2.5	2.5
Separate account assets	6,393.20	5,154.30
Short-term debt	1.9	1.2
Long-term debt	553.6	567.4
Estimate Of Fair Value Fair Value Disclosure [Member] | Level 1 [Member]	'	'
Separate account assets	6,249.20	5,007.50
Estimate Of Fair Value Fair Value Disclosure [Member] | Level 2 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	6,988.70	7,096.20
Separate account assets	144	146.8
Short-term debt	1.9	1.2
Long-term debt	553.6	567.4
Estimate Of Fair Value Fair Value Disclosure [Member] | Level 3 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	131.8	94.5
Commercial mortgage loans, net	5,769.60	5,946.30
Policy loans	2.5	2.5
Estimate Of Fair Value Fair Value Disclosure [Member] | U S Government Agencies Debt Securities [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	353.2	413
Estimate Of Fair Value Fair Value Disclosure [Member] | U S Government Agencies Debt Securities [Member] | Level 2 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	353.2	411.9
Estimate Of Fair Value Fair Value Disclosure [Member] | U S Government Agencies Debt Securities [Member] | Level 3 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	0	1.1
Estimate Of Fair Value Fair Value Disclosure [Member] | U S States And Political Subdivisions [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	140.3	168.4
Estimate Of Fair Value Fair Value Disclosure [Member] | U S States And Political Subdivisions [Member] | Level 2 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	140.3	166.7
Estimate Of Fair Value Fair Value Disclosure [Member] | U S States And Political Subdivisions [Member] | Level 3 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	0	1.7
Estimate Of Fair Value Fair Value Disclosure [Member] | Foreign Government Debt [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	65.5	72.1
Estimate Of Fair Value Fair Value Disclosure [Member] | Foreign Government Debt [Member] | Level 2 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	65.5	72.1
Estimate Of Fair Value Fair Value Disclosure [Member] | Foreign Government Debt [Member] | Level 3 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	'	0
Estimate Of Fair Value Fair Value Disclosure [Member] | Corporate Bond Securities [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	6,545.70	6,525.90
Estimate Of Fair Value Fair Value Disclosure [Member] | Corporate Bond Securities [Member] | Level 2 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	6,429.70	6,445.50
Estimate Of Fair Value Fair Value Disclosure [Member] | Corporate Bond Securities [Member] | Level 3 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	116	80.4
Estimate Of Fair Value Fair Value Disclosure [Member] | Investment Type Contracts [Member]	'	'
Other policyholder funds	5,632.70	5,331.30
Estimate Of Fair Value Fair Value Disclosure [Member] | Investment Type Contracts [Member] | Level 3 [Member]	'	'
Other policyholder funds	5,632.70	5,331.30
Estimate Of Fair Value Fair Value Disclosure [Member] | S And P Five Hundred Index Options [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	15.8	11.3
Estimate Of Fair Value Fair Value Disclosure [Member] | S And P Five Hundred Index Options [Member] | Level 2 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	'	0
Estimate Of Fair Value Fair Value Disclosure [Member] | S And P Five Hundred Index Options [Member] | Level 3 [Member]	'	'
Total fixed maturity securities-available-for-sale, Fair Value	15.8	11.3
Estimate Of Fair Value Fair Value Disclosure [Member] | Index Based Interest Guarantees [Member]	'	'
Index-based interest guarantees	67.6	57.4
Estimate Of Fair Value Fair Value Disclosure [Member] | Index Based Interest Guarantees [Member] | Level 3 [Member]	'	'
Index-based interest guarantees	$67.60	$57.40

Fair_Value_Estimated_Fair_Valu1

Fair Value (Estimated Fair Values Of Assets And Liabilities Measured And Recorded At Fair Value On A Recurring Basis) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$131.80		$94.50		$73.10
Unobservable Inputs	'(a) (b) (a) 1% 0% 7% 0% 5% 6% 13% 16% 53% 36%	[1],[2],[3]	'1% 0% 7% 0% 5% 5% 38% 14% 36% 36% (b)	[1],[2]	'
Fair Value Measurements Significant Assumptions	'Various assumptions Reduction on appraisal Expected future, Various assumptions Reduction on appraisal , Capitalization rate (c)		'		'
Fair Value Measurements Valuation Techniques	'Black-Scholes option pricing model Appraisals Discounted cash , Black-Scholes option pricing model Appraisals, Cash flows		'		'
Commercial Mortgage Loans [Member]	'		'		'
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	68.7		53.9		'
Real Estate Owned [Member]	'		'		'
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	35.2		48.2		'
S And P Five Hundred Index Options [Member]	'		'		'
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	15.8		11.3		7.2
S And P Five Hundred Index Options [Member] | Various Assumptions [Member] | Black Scholes Option Pricing Model [Member]	'		'		'
Unobservable Inputs	'		'(a)	[3]	'
Index Based Interest Guarantees [Member]	'		'		'
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	$67.60		$57.40		$49.50
Index Based Interest Guarantees [Member] | Various Assumptions [Member] | Black Scholes Option Pricing Model [Member]	'		'		'
Unobservable Inputs	'		'(a)	[3]	'
[1]	Capitalization rates are used as an internal analysis in converting the underlying propertybs income to an estimated property value.
[2]	Represents various actuarial assumptions which include combined lapse, mortality and withdrawal decrement rates which generally have a range of inputs from 5%-36% for both December 31, 2013 and December 31, 2012.
[3]	Represents various assumptions derived from market data, which include estimates of bid ask spreads and the implied volatilities for the S&P 500 Index.

Fair_Value_Assets_And_Liabilit

Fair Value (Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Significant Unobservable Level 3 Inputs) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Beginning asset balance	$94.50	$73.10
Total Realized/Unrealized Gains (Losses) Included in Net Income	14.4	7.8
Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)	6.2	7.9
Purchases	9.4	22.7
Issuance	0	0
Sales	0	-2.2
Settlements	-19.3	-13.2
Transfers into Level 3	61.6	8.4
Transfers out of Level 3	-35	-10
Ending asset balance	131.8	94.5
U S Government Agencies Debt Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Beginning asset balance	1.1	0.5
Total Realized/Unrealized Gains (Losses) Included in Net Income	0	0
Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)	0	0
Purchases	0	1.1
Issuance	0	0
Sales	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	-1.1	-0.5
Ending asset balance	0	1.1
U S States And Political Subdivisions [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Beginning asset balance	1.7	1.4
Total Realized/Unrealized Gains (Losses) Included in Net Income	0	0
Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)	0	-0.1
Purchases	0	0
Issuance	0	0
Sales	0	0
Settlements	0	0
Transfers into Level 3	0	0.4
Transfers out of Level 3	-1.7	0
Ending asset balance	0	1.7
Corporate Bond Securities [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Beginning asset balance	80.4	64
Total Realized/Unrealized Gains (Losses) Included in Net Income	0	0
Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)	6.2	8
Purchases	0	12.1
Issuance	0	0
Sales	0	-2.2
Settlements	0	0
Transfers into Level 3	61.6	8
Transfers out of Level 3	-32.2	-9.5
Ending asset balance	116	80.4
S And P Five Hundred Index Options [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Beginning asset balance	11.3	7.2
Total Realized/Unrealized Gains (Losses) Included in Net Income	14.4	7.8
Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)	0	0
Purchases	9.4	9.5
Issuance	0	0
Sales	0	0
Settlements	-19.3	-13.2
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Ending asset balance	15.8	11.3
Index Based Interest Guarantees [Member]	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'
Beginning Asset (Liability)	57.4	49.5
Total realized/unrealized gains (losses) Included in net income	9	6.4
Total realized/unrealized gains (losses) Included in other comprehensive income (loss)	0	0
Purchases	0	0
Issuances	6	4.9
Sales	0	0
Settlements	-4.8	-3.4
Transfers in to Level 3	0	0
Transfers out of Level 3	0	0
Ending Liability	$67.60	$57.40

Fair_Value_Changes_In_Unrealiz

Fair Value (Changes In Unrealized Gains (Losses) Included In Net Income) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
S And P Five Hundred Index Options [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]	'	'
Changes in assets unrealized gains (losses) included in net income relating to positions still held	$6.40	$1.80
Index Based Interest Guarantees [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]	'	'
Changes in unrealized gains (losses) included in net income relating to liability positions still held	($12.90)	($7.80)

Fair_Value_Assets_Measured_At_

Fair Value (Assets Measured At Fair Value On A Nonrecurring Basis) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Total assets measured on a nonrecurring basis during the period and still held as of the balance sheet date	$103.90	$102.10
Level 3 [Member]	'	'
Total assets measured on a nonrecurring basis during the period and still held as of the balance sheet date	103.9	102.1
Commercial Mortgage Loans [Member]	'	'
Total assets measured on a nonrecurring basis during the period and still held as of the balance sheet date	68.7	53.9
Commercial Mortgage Loans [Member] | Level 3 [Member]	'	'
Total assets measured on a nonrecurring basis during the period and still held as of the balance sheet date	68.7	53.9
Real Estate Owned [Member]	'	'
Total assets measured on a nonrecurring basis during the period and still held as of the balance sheet date	35.2	48.2
Real Estate Owned [Member] | Level 3 [Member]	'	'
Total assets measured on a nonrecurring basis during the period and still held as of the balance sheet date	$35.20	$48.20

Investments_Narrative_Details

Investments (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Investments [Line Items]	'	'	'
Callable bonds without a make-whole provision of fixed maturity available-for-sale securities, percentage	4.25%	'	'
Callable bonds without a make-whole provision of fixed maturity available-for-sale securities, amount	$302.80	'	'
Securities deposited for the benefit of policyholders in accordance with state regulations	7.4	7.9	'
Interest income recognized on impaired commercial mortgage loans	4.2	4.1	3.8
Cash received by the company as interest on impaired commercial mortgage loans	3.8	4	3.1
Commercial mortgage loans that were at least 60 days past due	15.2	21.3	'
60 day delinquency proportion of commercial mortgage loan portfolio	0.28%	0.40%	'
Fixed maturity securities-available-for-sale (amortized cost of $6,023.0 and $5,923.6)	7,120.50	7,190.70	'
Investments And Commercial Banks In Euro Zone Member [Member]	'	'	'
Schedule of Investments [Line Items]	'	'	'
Fixed maturity securities-available-for-sale (amortized cost of $6,023.0 and $5,923.6)	$60.70	'	'
Available-for-sale Securities, Debt Securities, Percentage	0.90%	'	'

Investments_Amortized_Costs_An

Investments (Amortized Costs And Fair Values Of Fixed Maturity Securities Available-For-Sale) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Schedule of Investments [Line Items]	'	'
Total fixed maturity securities-available-for-sale, Amortized Cost	$6,811.90	$6,517.70
Total fixed maturity securities-available-for-sale, Fair Value	7,120.50	7,190.70
Estimate Of Fair Value Fair Value Disclosure [Member]	'	'
Schedule of Investments [Line Items]	'	'
Total fixed maturity securities-available-for-sale, Amortized Cost	6,811.90	6,517.70
Total fixed maturity securities-available-for-sale, Unrealized Gains	385.8	676.8
Total fixed maturity securities-available-for-sale, Unrealized Losses	-77.2	-3.8
Total fixed maturity securities-available-for-sale, Fair Value	7,120.50	7,190.70
U S Government Agencies Debt Securities [Member] | Estimate Of Fair Value Fair Value Disclosure [Member]	'	'
Schedule of Investments [Line Items]	'	'
Total fixed maturity securities-available-for-sale, Amortized Cost	320.8	351.5
Total fixed maturity securities-available-for-sale, Unrealized Gains	32.8	61.5
Total fixed maturity securities-available-for-sale, Unrealized Losses	-0.4	0
Total fixed maturity securities-available-for-sale, Fair Value	353.2	413
U S States And Political Subdivisions [Member] | Estimate Of Fair Value Fair Value Disclosure [Member]	'	'
Schedule of Investments [Line Items]	'	'
Total fixed maturity securities-available-for-sale, Amortized Cost	134.3	151.6
Total fixed maturity securities-available-for-sale, Unrealized Gains	6.8	16.8
Total fixed maturity securities-available-for-sale, Unrealized Losses	-0.8	0
Total fixed maturity securities-available-for-sale, Fair Value	140.3	168.4
Foreign Government Debt [Member] | Estimate Of Fair Value Fair Value Disclosure [Member]	'	'
Schedule of Investments [Line Items]	'	'
Total fixed maturity securities-available-for-sale, Amortized Cost	58.9	61.3
Total fixed maturity securities-available-for-sale, Unrealized Gains	6.6	10.8
Total fixed maturity securities-available-for-sale, Unrealized Losses	0	0
Total fixed maturity securities-available-for-sale, Fair Value	65.5	72.1
Corporate Bond Securities [Member] | Estimate Of Fair Value Fair Value Disclosure [Member]	'	'
Schedule of Investments [Line Items]	'	'
Total fixed maturity securities-available-for-sale, Amortized Cost	6,282.10	5,942
Total fixed maturity securities-available-for-sale, Unrealized Gains	339.6	587.7
Total fixed maturity securities-available-for-sale, Unrealized Losses	-76	-3.8
Total fixed maturity securities-available-for-sale, Fair Value	6,545.70	6,525.90
S And P Five Hundred Index Options [Member] | Estimate Of Fair Value Fair Value Disclosure [Member]	'	'
Schedule of Investments [Line Items]	'	'
Total fixed maturity securities-available-for-sale, Amortized Cost	15.8	11.3
Total fixed maturity securities-available-for-sale, Unrealized Gains	0	0
Total fixed maturity securities-available-for-sale, Unrealized Losses	0	0
Total fixed maturity securities-available-for-sale, Fair Value	$15.80	$11.30

Investments_Schedule_Of_Contra

Investments (Schedule Of Contractual Maturities Of Fixed Maturity Securities Available-For-Sale) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Investments [Abstract]	'	'
Due in one year or less, Amortized cost	$486.20	$699.20
Due after one year through five years, Amortized cost	2,974.50	2,779.90
Due after five years through ten years, Amortized Cost	2,497.50	2,184.70
Due after ten years, Amortized Cost	853.7	853.9
Total fixed maturity securities-available-for-sale, Amortized Cost	6,811.90	6,517.70
Due in one year or less, Fair Value	495.1	712.9
Due after one year through five years, Fair Value	3,168.90	3,009.10
Due after five years through ten years, Fair Value	2,524.60	2,422.60
Due after ten years, Fair Value	931.9	1,046.10
Total fixed maturity securities-available-for-sale, Fair value	$7,120.50	$7,190.70

Investments_Commercial_Mortgag

Investments (Commercial Mortgage Loan Portfolio By Property Type By Geographic Region Within The U.S. And By U.S. State) (Details) (USD $)	Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	$5,405.10		$5,267.40
Commercial mortgage loans, Percentage	100.00%		100.00%
California [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	1,455.50		1,436.30
Commercial mortgage loans, Percentage	26.90%		27.30%
Texas [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	618.8		587
Commercial mortgage loans, Percentage	11.50%		11.10%
Florida [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	331.6		331.9
Commercial mortgage loans, Percentage	6.10%		6.30%
Georgia [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	310.7		311.5
Commercial mortgage loans, Percentage	5.80%		5.90%
Other States [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	2,688.50		2,600.70
Commercial mortgage loans, Percentage	49.70%		49.40%
Pacific [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	1,910.10	[1]	1,844.10	[1]
Commercial mortgage loans, Percentage	35.30%	[1]	35.00%	[1]
South Atlantic [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	1,090	[1]	1,069.20	[1]
Commercial mortgage loans, Percentage	20.20%	[1]	20.20%	[1]
West South Central [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	672.8	[1]	634.8	[1]
Commercial mortgage loans, Percentage	12.40%	[1]	12.10%	[1]
Mountain [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	611.4	[1]	612.7	[1]
Commercial mortgage loans, Percentage	11.30%	[1]	11.60%	[1]
East North Central [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	473.8	[1]	443.9	[1]
Commercial mortgage loans, Percentage	8.80%	[1]	8.40%	[1]
Middle Atlantic [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	223	[1]	240.3	[1]
Commercial mortgage loans, Percentage	4.10%	[1]	4.60%	[1]
West North Central [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	186.9	[1]	183	[1]
Commercial mortgage loans, Percentage	3.50%	[1]	3.50%	[1]
East South Central [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	166.6	[1]	150.5	[1]
Commercial mortgage loans, Percentage	3.10%	[1]	2.90%	[1]
New England [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	70.5	[1]	88.9	[1]
Commercial mortgage loans, Percentage	1.30%	[1]	1.70%	[1]
Retail [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	2,629.20		2,560.70
Commercial mortgage loans, Percentage	48.60%		48.60%
Office [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	982.4		960.8
Commercial mortgage loans, Percentage	18.20%		18.20%
Industrial [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	1,008.70		995.8
Commercial mortgage loans, Percentage	18.70%		18.90%
Hotels And Motels [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	276.3		280.8
Commercial mortgage loans, Percentage	5.10%		5.30%
Commercial [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	218.6		205.3
Commercial mortgage loans, Percentage	4.00%		4.00%
Apartment And Other [Member]	'		'
Commercial Mortgage Loans [Line Items]	'		'
Commercial mortgage loans, net	$289.90		$264
Commercial mortgage loans, Percentage	5.40%		5.00%
[1]	Geographic regions obtained from the American Council of Life Insurers Mortgage Loan Portfolio Profile.

Investments_Changes_In_Commerc

Investments (Changes In Commercial Mortgage Loan Loss Allowance) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Investments [Abstract]	'	'
Beginning balance	$46.60	$48.10
Provision	15.9	13.4
Charge-offs, net	-18.9	-14.9
Ending balance	43.6	46.6
Related Allowance	25.9	25.6
General loan loss allowance	17.7	21
Commercial mortgage loan loss allowance	$43.60	$46.60

Investments_Schedule_Of_Record

Investments (Schedule Of Recorded Investment In Commercial Mortgage Loans) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Investments [Abstract]	'	'	'
Commercial mortgage loans collectively evaluated for impairment	$5,334.40	$5,214.20	'
Commercial mortgage loans individually evaluated for impairment	114.3	99.8	'
Commercial mortgage loan loss allowance	-43.6	-46.6	-48.1
Total commercial mortgage loans	$5,405.10	$5,267.40	'

Investments_Performing_And_Non

Investments (Performing And Nonperforming Commercial Mortgage Loans By Property Type) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	$5,405.10	$5,267.40
Performing Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	5,393.20	5,250.30
Nonperforming Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	11.9	17.1
Retail [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	2,629.20	2,560.70
Retail [Member] | Performing Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	2,624.20	2,552.50
Retail [Member] | Nonperforming Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	5	8.2
Office [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	982.4	960.8
Office [Member] | Performing Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	979.6	955.8
Office [Member] | Nonperforming Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	2.8	5
Industrial [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	1,008.70	995.8
Industrial [Member] | Performing Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	1,004.60	993
Industrial [Member] | Nonperforming Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	4.1	2.8
Hotels And Motels [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	276.3	280.8
Hotels And Motels [Member] | Performing Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	276.3	280.8
Hotels And Motels [Member] | Nonperforming Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	0	0
Commercial [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	218.6	205.3
Commercial [Member] | Performing Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	218.6	204.7
Commercial [Member] | Nonperforming Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	0	0.6
Apartment And Other [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	289.9	264
Apartment And Other [Member] | Performing Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	289.9	263.5
Apartment And Other [Member] | Nonperforming Financing Receivable [Member]	'	'
Financing Receivable, Recorded Investment [Line Items]	'	'
Commercial mortgage loans, net	$0	$0.50

Investments_Impaired_Commercia

Investments (Impaired Commercial Mortgage Loans Identified In Management's Specific Review Of Probable Loan Losses And The Related Allowance) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financing Receivable, Impaired [Line Items]	'	'
Impaired recorded investment, with no related allowance	$26.60	$25.70
Impaired recorded investment, with related allowance	87.7	74.1
Total impaired recorded investment	114.3	99.8
Impaired unpaid principal balance, with no related allowance	26.6	25.7
Impaired unpaid principal balance, with related allowance	87.7	74.1
Total impaired unpaid principal balance	114.3	99.8
Related Allowance	25.9	25.6
Impaired recorded investment with no related allowance on nonaccrual status	9.1	6.5
Impaired recorded investment with related allowance on nonaccrual status	26.4	15.3
Total impaired recorded investment amount on Nonaccrual Status	35.5	21.8
Retail [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired recorded investment, with no related allowance	16.1	15.3
Impaired recorded investment, with related allowance	58.5	37.9
Impaired unpaid principal balance, with no related allowance	16.1	15.3
Impaired unpaid principal balance, with related allowance	58.5	37.9
Related Allowance	16.1	13.2
Impaired recorded investment with no related allowance on nonaccrual status	7.6	2.2
Impaired recorded investment with related allowance on nonaccrual status	21.6	9.3
Office [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired recorded investment, with no related allowance	3.9	5.2
Impaired recorded investment, with related allowance	9.7	10.3
Impaired unpaid principal balance, with no related allowance	3.9	5.2
Impaired unpaid principal balance, with related allowance	9.7	10.3
Related Allowance	3.8	2.5
Impaired recorded investment with no related allowance on nonaccrual status	1.5	4.1
Impaired recorded investment with related allowance on nonaccrual status	0.9	1.3
Industrial [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired recorded investment, with no related allowance	1	3.3
Impaired recorded investment, with related allowance	12.6	11.4
Impaired unpaid principal balance, with no related allowance	1	3.3
Impaired unpaid principal balance, with related allowance	12.6	11.4
Related Allowance	2.4	3.6
Impaired recorded investment with no related allowance on nonaccrual status	0	0.2
Impaired recorded investment with related allowance on nonaccrual status	1.4	2
Hotels And Motels [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired recorded investment, with no related allowance	0	'
Impaired unpaid principal balance, with no related allowance	0	'
Impaired recorded investment with no related allowance on nonaccrual status	0	'
Commercial [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired recorded investment, with no related allowance	1.8	'
Impaired recorded investment, with related allowance	6	11.4
Impaired unpaid principal balance, with no related allowance	1.8	'
Impaired unpaid principal balance, with related allowance	6	11.4
Related Allowance	3.6	6.2
Impaired recorded investment with no related allowance on nonaccrual status	0	'
Impaired recorded investment with related allowance on nonaccrual status	2.5	2.7
Apartment And Other [Member]	'	'
Financing Receivable, Impaired [Line Items]	'	'
Impaired recorded investment, with no related allowance	3.8	1.9
Impaired recorded investment, with related allowance	0.9	3.1
Impaired unpaid principal balance, with no related allowance	3.8	1.9
Impaired unpaid principal balance, with related allowance	0.9	3.1
Related Allowance	0	0.1
Impaired recorded investment with no related allowance on nonaccrual status	0	0
Impaired recorded investment with related allowance on nonaccrual status	$0	$0

Investments_Troubled_Debt_Rest

Investments (Troubled Debt Restructurings on Financing Receivables) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
	NumberOfLoans	NumberOfLoans
Financing Receivable, Modifications [Line Items]	'	'
Number of Loans	22	13
Pre - Restructuring Recorded Investment	$24.70	$13.20
Post - Restructuring Recorded Investment	25.6	14.5
Retail [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Loans	16	8
Pre - Restructuring Recorded Investment	20	8
Post - Restructuring Recorded Investment	20.8	9.2
Office [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Loans	3	0
Pre - Restructuring Recorded Investment	1.6	0
Post - Restructuring Recorded Investment	1.6	0
Industrial [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Loans	2	3
Pre - Restructuring Recorded Investment	2.2	2.4
Post - Restructuring Recorded Investment	2.3	2.4
Hotels And Motels [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Loans	0	0
Pre - Restructuring Recorded Investment	0	0
Post - Restructuring Recorded Investment	0	0
Commercial [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Loans	1	1
Pre - Restructuring Recorded Investment	0.9	1
Post - Restructuring Recorded Investment	0.9	1
Apartment And Other [Member]	'	'
Financing Receivable, Modifications [Line Items]	'	'
Number of Loans	0	1
Pre - Restructuring Recorded Investment	0	1.8
Post - Restructuring Recorded Investment	$0	$1.90

Investments_Average_Recorded_I

Investments (Average Recorded Investment In Impaired Commercial Mortgage Loans Before Specific Allowances For Losses) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Investments [Abstract]	'	'	'
Average recorded investment	$113.40	$101.30	$92.30

Investments_Aging_Of_Commercia

Investments (Aging Of Commercial Mortgage Loans By Property Type) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'
30 Days Past Due	$10.40	$25.60
60 Days Past Due	3.6	6
Greater Than 90 Days Past Due	11.6	15.3
Financing Receivable, Recorded Investment, Past Due, Total	25.6	46.9
Allowance Related to Past Due	-3.3	-4.2
Current	5,382.80	5,224.70
Total commercial mortgage loans	5,405.10	5,267.40
Retail [Member]	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'
30 Days Past Due	2.8	17.2
60 Days Past Due	0.3	4.9
Greater Than 90 Days Past Due	6.1	4.7
Financing Receivable, Recorded Investment, Past Due, Total	9.2	26.8
Allowance Related to Past Due	-1.5	-1.4
Current	2,621.50	2,535.30
Total commercial mortgage loans	2,629.20	2,560.70
Office [Member]	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'
30 Days Past Due	1.3	4.1
60 Days Past Due	0	0
Greater Than 90 Days Past Due	3.7	5.6
Financing Receivable, Recorded Investment, Past Due, Total	5	9.7
Allowance Related to Past Due	-0.9	-0.6
Current	978.3	951.7
Total commercial mortgage loans	982.4	960.8
Industrial [Member]	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'
30 Days Past Due	0	1.6
60 Days Past Due	3.3	0.5
Greater Than 90 Days Past Due	1.8	3.6
Financing Receivable, Recorded Investment, Past Due, Total	5.1	5.7
Allowance Related to Past Due	-0.9	-1.4
Current	1,004.50	991.5
Total commercial mortgage loans	1,008.70	995.8
Hotels And Motels [Member]	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'
30 Days Past Due	6.3	0
60 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Financing Receivable, Recorded Investment, Past Due, Total	6.3	0
Allowance Related to Past Due	0	0
Current	270	280.8
Total commercial mortgage loans	276.3	280.8
Commercial [Member]	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'
30 Days Past Due	0	2.7
60 Days Past Due	0	0
Greater Than 90 Days Past Due	0	1.4
Financing Receivable, Recorded Investment, Past Due, Total	0	4.1
Allowance Related to Past Due	0	-0.8
Current	218.6	202
Total commercial mortgage loans	218.6	205.3
Apartment And Other [Member]	'	'
Financing Receivable, Recorded Investment, Past Due [Line Items]	'	'
30 Days Past Due	0	0
60 Days Past Due	0	0.6
Greater Than 90 Days Past Due	0	0
Financing Receivable, Recorded Investment, Past Due, Total	0	0.6
Allowance Related to Past Due	0	0
Current	289.9	263.4
Total commercial mortgage loans	$289.90	$264

Investments_Schedule_Of_Gross_

Investments (Schedule Of Gross Unrealized Losses And Fair Value Of Investments) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	NumberOfInvestments	NumberOfInvestments
Schedule of Investments [Line Items]	'	'
Unrealized losses, Number	927	'
Unrealized losses, Amount	$77.20	'
Unrealized losses, Less than 12 months, Number	867	'
Unrealized losses, Less than 12 months, Amount	67.5	'
Unrealized losses, 12 or more months, Number	60	'
Unrealized losses, 12 or more months, Amount	9.7	'
Fair market value of securities with unrealized losses, Number	927	'
Fair market value of securities with unrealized losses, Amount	1,696.10	'
Fair market value of securities with unrealized losses, Less than 12 months, Number	867	'
Fair market value of securities with unrealized losses, Less than 12 months, Amount	1,590	'
Fair market value of securities with unrealized losses, 12 or more months, Number	60	'
Fair market value of securities with unrealized losses, 12 or more months, Amount	106.1	'
U S States And Political Subdivisions [Member]	'	'
Schedule of Investments [Line Items]	'	'
Unrealized losses, Number	10	'
Unrealized losses, Amount	0.8	'
Unrealized losses, Less than 12 months, Number	10	'
Unrealized losses, Less than 12 months, Amount	0.8	'
Unrealized losses, 12 or more months, Number	0	'
Unrealized losses, 12 or more months, Amount	0	'
Fair market value of securities with unrealized losses, Number	10	'
Fair market value of securities with unrealized losses, Amount	15.4	'
Fair market value of securities with unrealized losses, Less than 12 months, Number	10	'
Fair market value of securities with unrealized losses, Less than 12 months, Amount	15.4	'
Fair market value of securities with unrealized losses, 12 or more months, Number	0	'
Fair market value of securities with unrealized losses, 12 or more months, Amount	0	'
Corporate Bond Securities [Member]	'	'
Schedule of Investments [Line Items]	'	'
Unrealized losses, Number	908	198
Unrealized losses, Amount	76	3.8
Unrealized losses, Less than 12 months, Number	848	188
Unrealized losses, Less than 12 months, Amount	66.3	3.6
Unrealized losses, 12 or more months, Number	60	10
Unrealized losses, 12 or more months, Amount	9.7	0.2
Fair market value of securities with unrealized losses, Number	908	198
Fair market value of securities with unrealized losses, Amount	1,663.80	342.5
Fair market value of securities with unrealized losses, Less than 12 months, Number	848	188
Fair market value of securities with unrealized losses, Less than 12 months, Amount	1,557.70	335.5
Fair market value of securities with unrealized losses, 12 or more months, Number	60	10
Fair market value of securities with unrealized losses, 12 or more months, Amount	106.1	7
U S Government Agencies Debt Securities [Member]	'	'
Schedule of Investments [Line Items]	'	'
Unrealized losses, Number	9	'
Unrealized losses, Amount	0.4	'
Unrealized losses, Less than 12 months, Number	9	'
Unrealized losses, Less than 12 months, Amount	0.4	'
Unrealized losses, 12 or more months, Number	0	'
Unrealized losses, 12 or more months, Amount	0	'
Fair market value of securities with unrealized losses, Number	9	'
Fair market value of securities with unrealized losses, Amount	16.9	'
Fair market value of securities with unrealized losses, Less than 12 months, Number	9	'
Fair market value of securities with unrealized losses, Less than 12 months, Amount	16.9	'
Fair market value of securities with unrealized losses, 12 or more months, Number	0	'
Fair market value of securities with unrealized losses, 12 or more months, Amount	$0	'

Investments_Net_Investment_Inc

Investments (Net Investment Income Summarized By Investment Type) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary Of Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Investment income	'	'	'	'	'	'	'	'	$666.70	$664.10	$641.20
Investment expenses	'	'	'	'	'	'	'	'	-22.9	-22.3	-21.8
Tax-advantaged investment operating losses	'	'	'	'	'	'	'	'	-13.9	-13.3	-6.6
Net investment income	160.8	155.8	154.1	159.2	157.6	159.8	151.4	159.7	629.9	628.5	612.8
Total Fixed Maturity Securities [Member]	'	'	'	'	'	'	'	'	'	'	'
Summary Of Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Investment income	'	'	'	'	'	'	'	'	317.4	324.6	323.4
Bonds [Member]	'	'	'	'	'	'	'	'	'	'	'
Summary Of Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Investment income	'	'	'	'	'	'	'	'	303	316.8	323.6
S And P Five Hundred Index Options [Member]	'	'	'	'	'	'	'	'	'	'	'
Summary Of Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Investment income	'	'	'	'	'	'	'	'	14.4	7.8	-0.2
Commercial Mortgage Loans [Member]	'	'	'	'	'	'	'	'	'	'	'
Summary Of Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Investment income	'	'	'	'	'	'	'	'	341.7	331.9	310.2
Real Estate Investment [Member]	'	'	'	'	'	'	'	'	'	'	'
Summary Of Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Investment income	'	'	'	'	'	'	'	'	-1.4	-1	-0.4
Other Investment Classification [Member]	'	'	'	'	'	'	'	'	'	'	'
Summary Of Investment Income [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Investment income	'	'	'	'	'	'	'	'	$9	$8.60	$8

Investments_Schedule_Of_Gross_1

Investments (Schedule Of Gross Capital Gains And Losses By Investment Type) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Gross Capital Gains And Losses By Investment Type [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross capital gains	'	'	'	'	'	'	'	'	$15.40	$14.20	$48.70
Gross capital losses	'	'	'	'	'	'	'	'	-31.1	-22.9	-55.6
Total net capital losses	-2.8	-8.7	-2.6	-1.6	-1.9	-2.6	-4	-0.2	-15.7	-8.7	-6.9
Total Fixed Maturity Securities [Member]	'	'	'	'	'	'	'	'	'	'	'
Gross Capital Gains And Losses By Investment Type [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross capital gains	'	'	'	'	'	'	'	'	9.8	10.8	11.5
Gross capital losses	'	'	'	'	'	'	'	'	-2.3	-5	-2.4
Real Estate Investment [Member]	'	'	'	'	'	'	'	'	'	'	'
Gross Capital Gains And Losses By Investment Type [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross capital gains	'	'	'	'	'	'	'	'	0.7	0	35.2
Gross capital losses	'	'	'	'	'	'	'	'	-0.1	0	-0.5
Real Estate Owned [Member]	'	'	'	'	'	'	'	'	'	'	'
Gross Capital Gains And Losses By Investment Type [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross capital gains	'	'	'	'	'	'	'	'	2.3	1.3	1.1
Gross capital losses	'	'	'	'	'	'	'	'	-9.5	-3.5	-17.6
Commercial Mortgage Loans [Member]	'	'	'	'	'	'	'	'	'	'	'
Gross Capital Gains And Losses By Investment Type [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross capital gains	'	'	'	'	'	'	'	'	2.4	1.5	0.9
Gross capital losses	'	'	'	'	'	'	'	'	-15.9	-13.4	-32.7
Other Investment Classification [Member]	'	'	'	'	'	'	'	'	'	'	'
Gross Capital Gains And Losses By Investment Type [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross capital gains	'	'	'	'	'	'	'	'	0.2	0.6	0
Gross capital losses	'	'	'	'	'	'	'	'	($3.30)	($1)	($2.40)

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
	NumberOfDerivativeContracts
Derivative [Line Items]	'	'
S&P 500 index options purchased per month	1	'
Expiry Date Of S And P Five Hundred Index Options Purchased Years	'1 year 0 months 0 days	'
Notional amount of index option contract	$350.50	$315.20
Derivative Option premiums paid	9.4	9.5
Amount received for derivative options exercised	19.3	13.2
Maximum credit exposure required increase in S&P 500 Index, percentage	4.27%	'
Impact On Interest Credited Changes In Actuarial Assumptions	$4.10	$3.30

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Fair Value Of The Company's Derivative Assets And Liabilities) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Derivative [Line Items]	'	'
Derivative Assets	$15.80	'
S And P Five Hundred Index Options [Member] | Fixed Maturity Securities-Available-For-Sale [Member]	'	'
Derivative [Line Items]	'	'
Derivative Assets	15.8	11.3
Index Based Interest Guarantees [Member] | Other Policyholder Funds [Member]	'	'
Derivative [Line Items]	'	'
Derivative Liabilities	$67.60	$57.40

Derivative_Financial_Instrumen4

Derivative Financial Instruments (Gain Or Loss Recognized In Earnings From The Change in Fair Value of Derivative Assets and Liabilities) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net investment income	$160.80	$155.80	$154.10	$159.20	$157.60	$159.80	$151.40	$159.70	$629.90	$628.50	$612.80
Interest credited	'	'	'	'	'	'	'	'	176.4	171.3	161
Non designated [Member]	'	'	'	'	'	'	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net (loss) gain	'	'	'	'	'	'	'	'	5.4	1.4	-1.5
S And P Five Hundred Index Options [Member] | Non designated [Member]	'	'	'	'	'	'	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net investment income	'	'	'	'	'	'	'	'	14.4	7.8	-0.2
Index Based Interest Guarantees [Member] | Non designated [Member]	'	'	'	'	'	'	'	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Interest credited	'	'	'	'	'	'	'	'	($9)	($6.40)	($1.30)

Derivative_Financial_Instrumen5

Derivative Financial Instruments (Fair Value Of Derivative Assets And Its Maximum Credit Risk Exposure) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Derivative [Line Items]	'
Derivative Assets at Fair Value	$15.80
Maximum Credit Risk	20.2
Bank Of New York Mellon [Member]	'
Derivative [Line Items]	'
Derivative Assets at Fair Value	11
Maximum Credit Risk	14.3
Goldman Sachs [Member]	'
Derivative [Line Items]	'
Derivative Assets at Fair Value	4.8
Maximum Credit Risk	$5.90

Deferred_Acquisition_Costs_DAC2

Deferred Acquisition Costs ("DAC"), Value Of Business Acquired ("VOBA") And Other Intangible Assets (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Value Of Business Acquired [Member]	'	'
Indefinite-lived Intangible Assets by Major Class [Line Items]	'	'
Intangible assets, accumulated amortization	$68.70	$65.40
Intangible asset impairment writedown	1	0.8
Other Intangible Assets [Member]	'	'
Indefinite-lived Intangible Assets by Major Class [Line Items]	'	'
Intangible assets, accumulated amortization	$42.60	$36.50

Deferred_Acquisition_Costs_DAC3

Deferred Acquisition Costs ("DAC"), Value Of Business Acquired ("VOBA") And Other Intangible Assets (Schedule Of Activity For DAC, VOBA And Other Intangible Assets) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Finite Lived Intangible Assets [Line Items]	'	'	'
Carrying value at beginning of period, DAC	$284.90	$274.40	$250.10
Carrying value at beginning of period, VOBA	23.4	26.4	28.4
Carrying value at beginning of period, Other intangible assets	38.2	44.1	51.7
Total balance at beginning of period	346.5	344.9	330.2
Deferred or acquired, DAC	76.9	71.4	81.7
Total deferred or acquired	76.9	71.4	81.7
Amortization of DAC	-42.7	-60.9	-57.4
Amortized during period, VOBA	-3.3	-3	-2
Amortized during period, Other intangible assets	-6.1	-5.9	-7.6
Total amortized during period	-52.1	-69.8	-67
Carrying value at end of period, net DAC	319.1	284.9	274.4
Carrying value at end of period, net VOBA	20.1	23.4	26.4
Carrying value at end of period, net Other intangible assets	32.1	38.2	44.1
Total carrying value at end of period	$371.30	$346.50	$344.90

Deferred_Acquisition_Costs_DAC4

Deferred Acquisition Costs ("DAC"), Value Of Business Acquired ("VOBA") And Other Intangible Assets (Amount For DAC, VOBA Balances And Percentage To The Expected Gross Profit) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Deferred Acquisition Costs Value Of Business Acquired And Other Intangible Assets Disclosures [Abstract]	'	'
DAC	$80.10	$60.90
VOBA	$4.30	$5.90
DAC, percent	25.10%	21.40%
VOBA, percent	21.40%	25.20%

Deferred_Acquisition_Costs_DAC5

Deferred Acquisition Costs ("DAC"), Value Of Business Acquired ("VOBA") And Other Intangible Assets (Balances Of Unlocking On DAC And VOBA) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Deferred Acquisition Costs Value Of Business Acquired And Other Intangible Assets Disclosures [Abstract]	'	'	'
Decrease to DAC and VOBA	($1.70)	($1.70)	($0.90)

Deferred_Acquisition_Costs_DAC6

Deferred Acquisition Costs ("DAC"), Value Of Business Acquired ("VOBA") And Other Intangible Assets (Estimated Net Amortization Of VOBA For Next Five Years) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Deferred Acquisition Costs Value Of Business Acquired And Other Intangible Assets Disclosures [Abstract]	'
2014	$7.60
2015	7.2
2016	5.6
2017	4.2
2018	$4.20

Liability_For_Unpaid_Claims_Cl2

Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds (Change In The Liability For Unpaid Claims And Claim Adjustment Expenses) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Plus: reinsurance recoverable	$988.10	$972.40	'
Balance at end of the year, gross of reinsurance	4,021.90	4,005.90	3,857
Disability Insurance [Member]	'	'	'
Balance at beginning of the year, gross of reinsurance	4,005.90	3,857	3,716.30
Less: reinsurance recoverable	-128.6	-117.3	-110.5
Net balance at beginning of the year	3,877.30	3,739.70	3,605.80
Incurred related to Current year	1,081.70	1,140.30	1,077.10
Incurred related to Prior year's interest	180.3	181.2	175.9
Incurred related to Prior years	-133.2	-79.8	-46.5
Total incurred	1,128.80	1,241.70	1,206.50
Paid related to Current year	-345.9	-354.8	-347.1
Paid related to Prior year	-778.2	-749.3	-725.5
Total paid	-1,124.10	-1,104.10	-1,072.60
Net balance at end of the year	3,882	3,877.30	3,739.70
Plus: reinsurance recoverable	139.9	128.6	117.3
Balance at end of the year, gross of reinsurance	$4,021.90	$4,005.90	$3,857

Liability_For_Unpaid_Claims_Cl3

Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds (Future Policy Benefits And Claims) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds [Abstract]	'	'	'
Future policy benefits and claims	$5,846.90	$5,843.20	$5,683.60
Liability for Future Policy Benefits, Life	-751.7	-765.3	-765.4
Liability For Future Policy Benefits Individual Life	-603.6	-600.9	-597.2
Liability for Future Policy Benefits, Individual and Group Annuities and Supplementary Contracts	-220	-237.4	-244.2
Liability for Future Policy Benefits, Disability and Accident Benefits	-249.7	-233.7	-219.8
Liability for unpaid claims and claims adjustment expenses	$4,021.90	$4,005.90	$3,857

Liability_For_Unpaid_Claims_Cl4

Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds (Composition Of Other Policyholder Funds) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Other Policyholder Funds [Line Items]	'	'
Other policyholder funds	$6,051.60	$5,531.10
Employer Sponsored Defined Contribution And Benefit Plans Funds [Member]	'	'
Other Policyholder Funds [Line Items]	'	'
Other policyholder funds	1,954.10	1,554.10
Individual Fixed Rate Annuity Funds [Member]	'	'
Other Policyholder Funds [Line Items]	'	'
Other policyholder funds	2,541.70	2,434.90
Indexed Annuity Funds [Member]	'	'
Other Policyholder Funds [Line Items]	'	'
Other policyholder funds	440.8	409.2
Investment Only Stable Asset Funds [Member]	'	'
Other Policyholder Funds [Line Items]	'	'
Other policyholder funds	326.1	336.4
Other Policyholder Funds [Member]	'	'
Other Policyholder Funds [Line Items]	'	'
Other policyholder funds	$788.90	$796.50

Reinsurance_Narrative_Details

Reinsurance (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplementary Insurance Information, by Segment [Line Items]	'	'	'
Premiums assumed percentage to total company's premiums	4.60%	4.50%	4.50%
Recoveries recognized under reinsurance agreements	$79,800,000	$74,000,000	$75,900,000
Amounts recoverable from reinsurers	988,100,000	972,400,000	'
Northwestern Mutual Life Insurance Company [Member]	'	'	'
Supplementary Insurance Information, by Segment [Line Items]	'	'	'
Percentage of risk assumed	60.00%	'	'
Percentage of premiums received	60.00%	'	'
Market value of trust fund assets for reinsurance contract	233,600,000	'	'
Premiums assumed percentage to total company's premiums	3.00%	'	'
Protective Life Insurance Company [Member]	'	'	'
Supplementary Insurance Information, by Segment [Line Items]	'	'	'
Amounts recoverable from reinsurers	791,000,000	793,000,000	'
Canada Life [Member]	'	'	'
Supplementary Insurance Information, by Segment [Line Items]	'	'	'
Additional Net Capital, Change	'	100,000,000	'
Additional Net Capital, Balance	'	170,000,000	'
Group Life And Accidental Death And Dismemberment [Member]	'	'	'
Supplementary Insurance Information, by Segment [Line Items]	'	'	'
Maximum retention limit per individual	750,000	'	'
Maximum coverage for a single event catastrophe	520,000,000	'	'
Catastrophe reinsurance pool, number of participants	21	'	'
Catastrophe reinsurance pool annual membership fee	30,000	'	'
Maximum potential loss for a single event catastrophe submitted by a single company	112,600,000	'	'
Maximum potential loss for a single event catastrophe submitted by multiple companies	281,800,000	'	'
Group Disability Member [Member]	'	'	'
Supplementary Insurance Information, by Segment [Line Items]	'	'	'
Maximum monthly dollar amount of an individual policy which the company will payout on a monthly claim	15,000	'	'
Dental Insurance Premiums [Member]	'	'	'
Supplementary Insurance Information, by Segment [Line Items]	'	'	'
Ceded Premiums Written, Percentage	26.10%	'	'
Percentage of risk ceded to other entities	26.10%	'	'
Individual Disability Insurance Policies [Member]	'	'	'
Supplementary Insurance Information, by Segment [Line Items]	'	'	'
Maximum monthly dollar amount of an individual policy which the company will payout on a monthly claim	$6,000	'	'

Reinsurance_Schedule_Of_Reinsu

Reinsurance (Schedule Of Reinsurance Information) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
PremiumsNetLifeInsuranceInForceAbstract	'	'	'	'	'	'	'	'	'	'	'
Gross amount - life insurance in force	$321,881.70	'	'	'	$346,814.50	'	'	'	$321,881.70	$346,814.50	$350,623.10
Ceded premiums - life insurance in force	5,966.80	'	'	'	7,233.10	'	'	'	5,966.80	7,233.10	55,126
Assumed Premiums - life insurance in force	57.7	'	'	'	65.1	'	'	'	57.7	65.1	71.7
Net amount - life insurance in force	315,972.60	'	'	'	339,646.50	'	'	'	315,972.60	339,646.50	295,568.80
Percentage of amount assumed to net - life insurance in force	'	'	'	'	'	'	'	'	0.00%	0.00%	0.00%
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross Amount	'	'	'	'	'	'	'	'	2,157.10	2,201.20	2,184.10
Ceded to Other Companies	'	'	'	'	'	'	'	'	129.5	134.7	128.3
Assumed From Other Companies	'	'	'	'	'	'	'	'	96.7	97.4	97.5
Net Amount	528.6	524.4	535.1	536.2	533.8	528.7	548.1	553.3	2,124.30	2,163.90	2,153.30
Percentage of Amount Assumed to Net	'	'	'	'	'	'	'	'	4.60%	4.50%	4.50%
Life Insurance Segment [Member]	'	'	'	'	'	'	'	'	'	'	'
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross Amount	'	'	'	'	'	'	'	'	898.5	937.9	942.3
Ceded to Other Companies	'	'	'	'	'	'	'	'	48.5	51	52.2
Assumed From Other Companies	'	'	'	'	'	'	'	'	0	0	0
Net Amount	'	'	'	'	'	'	'	'	850	886.9	890.1
Percentage of Amount Assumed to Net	'	'	'	'	'	'	'	'	0.00%	0.00%	0.00%
Accident And Health Insurance Segment [Member]	'	'	'	'	'	'	'	'	'	'	'
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Gross Amount	'	'	'	'	'	'	'	'	1,258.60	1,263.30	1,241.80
Ceded to Other Companies	'	'	'	'	'	'	'	'	81	83.7	76.1
Assumed From Other Companies	'	'	'	'	'	'	'	'	96.7	97.4	97.5
Net Amount	'	'	'	'	'	'	'	'	$1,274.30	$1,277	$1,263.20
Percentage of Amount Assumed to Net	'	'	'	'	'	'	'	'	7.60%	7.60%	7.70%

Reinsurance_Of_Blocks_Of_Busin1

Reinsurance Of Blocks Of Business (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
	NumberOfGroupInsuranceContracts
	NumberOfInsuredIndividuals
TIAA [Member]	'
Ceded Credit Risk [Line Items]	'
Ceding commission paid	$75
Market value of assets and statutory liabilities received	705
Market value of trust fund assets for reinsurance contract	215.1
Number of group insurance contracts assumed	1,800
Number of insured individuals assumed	650,000
VOBA recorded	60
Minnesota Life [Member]	'
Ceded Credit Risk [Line Items]	'
Ceding commission paid	55
Market value of assets and statutory liabilities received	500
Market value of trust fund assets for reinsurance contract	569.2
Protective Life Insurance Company [Member]	'
Ceded Credit Risk [Line Items]	'
Ceding commission received	90
Market value of assets and statutory liabilities transferred	$790

Insurance_Information_Details

Insurance Information (Details) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2012

Sep. 30, 2012

Jun. 30, 2012

Mar. 31, 2012

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2011

Dec. 31, 2010

Insurance Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

DAC

$319.10

'

'

'

$284.90

'

'

'

$319.10

$284.90

$274.40

$250.10

Future Policy Benefits And Claims

5,846.90

'

'

'

5,843.20

'

'

'

5,846.90

5,843.20

'

'

Other Policyholder Funds

6,051.60

'

'

'

5,531.10

'

'

'

6,051.60

5,531.10

'

'

Premiums Revenues

528.6

524.4

535.1

536.2

533.8

528.7

548.1

553.3

2,124.30

2,163.90

2,153.30

'

Net Investment Income

160.8

155.8

154.1

159.2

157.6

159.8

151.4

159.7

629.9

628.5

612.8

'

Amortization of DAC

'

'

'

'

'

'

'

'

42.7

60.9

57.4

'

Insurance Products [Member]

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

DAC

319.1

[1]

'

'

'

284.9

[1]

'

'

'

319.1

[1]

284.9

[1]

274.4

[1]

'

Future Policy Benefits And Claims

5,846.90

'

'

'

5,843.20

'

'

'

5,846.90

5,843.20

5,683.60

'

Other Policyholder Funds

6,051.60

'

'

'

5,531.10

'

'

'

6,051.60

5,531.10

5,078.10

'

Premiums Revenues

'

'

'

'

'

'

'

'

2,124.30

2,163.90

2,153.30

'

Net Investment Income

'

'

'

'

'

'

'

'

613.8

618.3

604

'

Benefits, Claims and Interest Credited

'

'

'

'

'

'

'

'

1,831.80

1,964.30

1,932.20

'

Amortization of DAC

'

'

'

'

'

'

'

'

62.9

61.6

59.1

'

Other Operating Expenses

'

'

'

'

'

'

'

'

694.8

[2]

706.8

[2]

694.8

[2]

'

Insurance Services [Member]

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Premiums Revenues

'

'

'

'

'

'

'

'

2,117.40

2,157.20

2,145.30

'

Net Investment Income

'

'

'

'

'

'

'

'

320.6

339.7

341.3

'

Insurance Services [Member] | Insurance Products [Member]

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

DAC

239

[1]

'

'

'

223.9

[1]

'

'

'

239

[1]

223.9

[1]

213.7

[1]

'

Future Policy Benefits And Claims

5,627

'

'

'

5,605.80

'

'

'

5,627

5,605.80

5,439.40

'

Other Policyholder Funds

514.2

'

'

'

557

'

'

'

514.2

557

579.3

'

Premiums Revenues

'

'

'

'

'

'

'

'

2,117.40

2,157.20

2,145.30

'

Net Investment Income

'

'

'

'

'

'

'

'

320.6

339.7

341.3

'

Benefits, Claims and Interest Credited

'

'

'

'

'

'

'

'

1,642

1,777.50

1,755.50

'

Amortization of DAC

'

'

'

'

'

'

'

'

45.2

45.8

42.9

'

Other Operating Expenses

'

'

'

'

'

'

'

'

538.9

[2]

553.5

[2]

542.2

[2]

'

Employee Benefits [Member]

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Premiums Revenues

'

'

'

'

'

'

'

'

1,926.90

1,980.60

1,973

'

Net Investment Income

'

'

'

'

'

'

'

'

267.8

286

288.6

'

Employee Benefits [Member] | Insurance Products [Member]

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

DAC

24.2

[1]

'

'

'

24.6

[1]

'

'

'

24.2

[1]

24.6

[1]

30.1

[1]

'

Future Policy Benefits And Claims

3,995.90

'

'

'

4,025.60

'

'

'

3,995.90

4,025.60

3,910

'

Other Policyholder Funds

315.3

'

'

'

353.5

'

'

'

315.3

353.5

376.9

'

Premiums Revenues

'

'

'

'

'

'

'

'

1,926.90

1,980.60

1,973

'

Net Investment Income

'

'

'

'

'

'

'

'

267.8

286

288.6

'

Benefits, Claims and Interest Credited

'

'

'

'

'

'

'

'

1,520.20

1,661.30

1,639.60

'

Amortization of DAC

'

'

'

'

'

'

'

'

22.6

23.9

22.8

'

Other Operating Expenses

'

'

'

'

'

'

'

'

473.2

[2]

489.2

[2]

478.1

[2]

'

Individual Disability [Member]

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Premiums Revenues

'

'

'

'

'

'

'

'

190.5

176.6

172.3

'

Net Investment Income

'

'

'

'

'

'

'

'

52.8

53.7

52.7

'

Individual Disability [Member] | Insurance Products [Member]

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

DAC

214.8

[1]

'

'

'

199.3

[1]

'

'

'

214.8

[1]

199.3

[1]

183.6

[1]

'

Future Policy Benefits And Claims

1,631.10

'

'

'

1,580.20

'

'

'

1,631.10

1,580.20

1,529.40

'

Other Policyholder Funds

198.9

'

'

'

203.5

'

'

'

198.9

203.5

202.4

'

Premiums Revenues

'

'

'

'

'

'

'

'

190.5

176.6

172.3

'

Net Investment Income

'

'

'

'

'

'

'

'

52.8

53.7

52.7

'

Benefits, Claims and Interest Credited

'

'

'

'

'

'

'

'

121.8

116.2

115.9

'

Amortization of DAC

'

'

'

'

'

'

'

'

22.6

21.9

20.1

'

Other Operating Expenses

'

'

'

'

'

'

'

'

65.7

[2]

64.3

[2]

64.1

[2]

'

Asset Management Segment [Member]

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Premiums Revenues

'

'

'

'

'

'

'

'

6.9

6.7

8

'

Net Investment Income

'

'

'

'

'

'

'

'

293.2

278.6

262.7

'

Asset Management Segment [Member] | Insurance Products [Member]

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Information [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

DAC

80.1

[1]

'

'

'

61

[1]

'

'

'

80.1

[1]

61

[1]

60.7

[1]

'

Future Policy Benefits And Claims

219.9

'

'

'

237.4

'

'

'

219.9

237.4

244.2

'

Other Policyholder Funds

5,537.40

'

'

'

4,974.10

'

'

'

5,537.40

4,974.10

4,498.80

'

Premiums Revenues

'

'

'

'

'

'

'

'

6.9

6.7

8

'

Net Investment Income

'

'

'

'

'

'

'

'

293.2

278.6

262.7

'

Benefits, Claims and Interest Credited

'

'

'

'

'

'

'

'

189.8

186.8

176.7

'

Amortization of DAC

'

'

'

'

'

'

'

'

17.7

15.8

16.2

'

Other Operating Expenses

'

'

'

'

'

'

'

'

$155.90

[2]

$153.30

[2]

$152.60

[2]

'

[1]

See bNote 1bSummary of Significant Accounting PoliciesbDAC, VOBA and Other Intangible Assetsb And bNote 12bDAC, VOBA and Other Intangible Assets.b

[2]

Other operating expenses include operating expenses, commissions and bonuses, premium taxes, interest expense and the net increase in DAC, VOBA and other intangible assets.

Regulatory_matters_NarrativeDe

Regulatory matters (Narrative)(Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Insurance Information [Line Items]	'	'	'
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	$1,359	$1,259.60	'
Company Action Level RBC [Member]	'	'	'
Insurance Information [Line Items]	'	'	'
Percentage of company's capital and surplus of required capital and surplus	398.00%	365.00%	'
Authorized Control Level RBC [Member]	'	'	'
Insurance Information [Line Items]	'	'	'
Required statutory capital and surplus	186.6	189.1	'
Percentage of company's capital and surplus of required capital and surplus	796.00%	730.00%	'
Parent Company [Member]	'	'	'
Insurance Information [Line Items]	'	'	'
Capital contributions to subsidiaries	0.7	14.5	9
Standard Insurance Company [Member]	'	'	'
Insurance Information [Line Items]	'	'	'
Dividends which can be declared without additional statutory approval	195.1	132.7	'
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	1,290	1,190	'
Dividends from Insurance subidiaries to Parent Company	130	320	'
Standard Life Insurance Company Of New York [Member]	'	'	'
Insurance Information [Line Items]	'	'	'
Capital contributions to subsidiaries	$0	$10	'

Regulatory_Matters_Reconciliat

Regulatory Matters (Reconciliation Of The Statutory Capital And Surplus Of The Insurance) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Statutory capital and surplus	$1,359	$1,259.60	'	'
GAAP equity	2,152.80	2,169	1,990.40	1,894.60
Future Policy Benefits And Other Policyholder Funds [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	325.8	301.7	'	'
Dac Voba And Other Intangible Assets [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	351.6	322	'	'
Deferred Tax Liabilities [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	-265.3	-236.8	'	'
Asset Valuation Reserve [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	127.5	117.5	'	'
Valuation Of Investments [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	236.4	449.8	'	'
Interest Maintenance Reserve [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	25.5	24.8	'	'
Equity Of Stancorp And It Non Insurance Subsidiaries [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	116.1	51.6	'	'
Non Admitted Assets [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	178.2	144.1	'	'
Pension and postretirement benefit plans [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	-6.6	3.6	'	'
Capital Lease Obligations [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	-3.4	-2.4	'	'
Surplus Note [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	-250	-250	'	'
Other Net [Member]	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'
Adjustments to reconcile to GAAP equity:	($42)	($16.50)	'	'

Regulatory_Matters_Reconciliat1

Regulatory Matters (Reconciliation Of The Statutory Gain From Operations) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Statutory gain from operations	'	'	'	'	'	'	'	'	$198.50	$131.50	$125.80
GAAP net income	65	59	57.7	46.8	38.4	44.9	20	35.2	228.5	138.5	136.7
Future Policy Benefits And Other Policyholder Funds [Member]	'	'	'	'	'	'	'	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Adjustments to reconcile to GAAP net income:	'	'	'	'	'	'	'	'	11	26.4	48
Dac And Voba Net Of Amortization [Member]	'	'	'	'	'	'	'	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Adjustments to reconcile to GAAP net income:	'	'	'	'	'	'	'	'	9.4	5.5	19.2
Deferred Income Taxes [Member]	'	'	'	'	'	'	'	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Adjustments to reconcile to GAAP net income:	'	'	'	'	'	'	'	'	-13.5	-22.4	-42.1
Current Income Taxes [Member]	'	'	'	'	'	'	'	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Adjustments to reconcile to GAAP net income:	'	'	'	'	'	'	'	'	9.6	17.2	24.7
Earnings Of Stancorp And Its Non Insurance Subsidiaries [Member]	'	'	'	'	'	'	'	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Adjustments to reconcile to GAAP net income:	'	'	'	'	'	'	'	'	-8.9	-23.8	-18.9
Deferred Capital Gains Interest Maintenance Reserve [Member]	'	'	'	'	'	'	'	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Adjustments to reconcile to GAAP net income:	'	'	'	'	'	'	'	'	0.7	5	7.2
Other Net [Member]	'	'	'	'	'	'	'	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Adjustments to reconcile to GAAP net income:	'	'	'	'	'	'	'	'	-0.8	0.4	-6.3
Pension And Postretirement Benefit Plans [Member]	'	'	'	'	'	'	'	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Adjustments to reconcile to GAAP net income:	'	'	'	'	'	'	'	'	17.6	-1.7	-3.1
Share Based Compnesation Statutory Reconciliation [Member]	'	'	'	'	'	'	'	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Adjustments to reconcile to GAAP net income:	'	'	'	'	'	'	'	'	-3.6	-5.4	-5.2
Investments Statutory Reconciliation [Member]	'	'	'	'	'	'	'	'	'	'	'
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Adjustments to reconcile to GAAP net income:	'	'	'	'	'	'	'	'	$8.50	$5.80	($12.60)

LongTerm_Debt_Narrative_Detail

Long-Term Debt (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Debt Instrument [Line Items]	'	'	'
Repayment of senior debt	$0	$250	$0
Junior Subordinated Debt [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Debt instrument, face amount	300	'	'
Debt instrument, interest rate, stated percentage	6.90%	'	'
Debt instrument, maturity date	1-Jun-67	'	'
Debt instrument, non-callable at par, years	'10 years 0 months 0 days	'	'
Debt instrument, call date, earliest	1-Jun-17	'	'
Debt instrument, term of stated percentage, initial years	'10 years 0 months 0 days	'	'
Debt Instrument, Description of Variable Rate Basis	'LIBOR	'	'
Debt instrument, floating interest rate base to be added to three-month LIBOR.	2.51%	'	'
Debt instrument, option to defer interest payments, years	'5 years 0 months 0 days	'	'
Senior Notes 2012 [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Debt instrument, interest rate, stated percentage	6.88%	'	'
Repayment of senior debt	250	'	'
Senior Notes 2022 [Member]	'	'	'
Debt Instrument [Line Items]	'	'	'
Debt issuance date	10-Aug-12	'	'
Debt instrument, face amount	$250	'	'
Debt instrument, interest rate, stated percentage	5.00%	'	'
Debt instrument, maturity date	15-Aug-22	'	'

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'	'
Long-term debt	$551.90	$551.40
Junior Subordinated Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	300	300
Other Long Term Borrowings [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	1.9	1.4
Senior Notes [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	$250	$250

Commitments_And_Contingencies_1

Commitments And Contingencies (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Commitments And Contingencies [Line Items]	'	'	'
Line of credit facility, amount outstanding	$0	'	'
Total rent expense, operating lease commitments	13.7	15.2	16.4
Loan Origination Commitments [Member]	'	'	'
Commitments And Contingencies [Line Items]	'	'	'
Total outstanding commitments to fund commercial mortgage loans	197.6	'	'
Maximum Member	'	'	'
Commitments And Contingencies [Line Items]	'	'	'
Operating lease renewal period	'10 years 0 months 0 days	'	'
Fixed interest rate on commercial mortgage loan commitments	5.75%	'	'
Minimum Member	'	'	'
Commitments And Contingencies [Line Items]	'	'	'
Operating lease renewal period	'1 year 0 months 0 days	'	'
Fixed interest rate on commercial mortgage loan commitments	4.25%	'	'
Unsecured Revolving Credit Facility [Member]	'	'	'
Commitments And Contingencies [Line Items]	'	'	'
Line of Credit Facility, Borrowing Capacity, Description	'Upon the request of StanCorp and with the consent of the lenders under the Facility, the Facility can be increased to $350 million.	'	'
Line of Credit Facility, Current Borrowing Capacity	250	'	'
Line of credit facility, maximum borrowing capacity	350	'	'
Line of credit facility, expiration date	22-Jun-17	'	'
Line Of Credit Facility Number Of One Year Extension Periods	1	'	'
Line of Credit Facility, Covenant Terms	'Under the agreement, the Company is subject to two financial covenants that are based on the Company's ratio of total debt to total capitalization and consolidated net worth. The Company is also subject to covenants that limit subsidiary indebtedness.	'	'
Line of credit facility, financial covenants, number	2	'	'
Interest rate description	'The Facility is subject to pricing levels based upon the Company's publicly announced debt ratings and includes an interest rate option at the election of the borrower of a base rate plus the applicable margin or LIBOR plus the applicable margin, plus facility and utilization fees.	'	'
Junior Subordinated Debt [Member]	'	'	'
Commitments And Contingencies [Line Items]	'	'	'
Debt instrument, face amount	300	'	'
Debt instrument, interest rate, stated percentage	6.90%	'	'
Senior Notes 2022 [Member]	'	'	'
Commitments And Contingencies [Line Items]	'	'	'
Debt instrument, face amount	$250	'	'
Debt instrument, interest rate, stated percentage	5.00%	'	'

Commitments_And_Contingencies_2

Commitments And Contingencies (Future Minimum Payments Under The Leases) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Commitments And Contingencies [Abstract]	'
2014	$8.90
2015	7.9
2016	7.6
2017	7.1
2018	2.6
Thereafter	$1.80

Commitments_And_Contingencies_3

Commitments And Contingencies (Minimum Future Rental Receivables On Non-Cancelable Leases Of Retail And Office Space) (Details) (USD $)	Dec. 31, 2013
In Millions, unless otherwise specified
Commitments And Contingencies [Abstract]	'
2014	$7.40
2015	6.6
2016	4.7
2017	2.1
2018	1.5
Thereafter	$5.90

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'		'
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	$309.30		$235.10		'
Other Comprehensive Income Loss Before Reclassifications Net Of Tax	-164.1		71.4		'
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	-10.5		2.8		'
Other comprehensive income	-174.6		74.2		74.2
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	134.7		309.3		235.1
Unrealized Gains (losses) on Available For Sale Securities [Member]	'		'		'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'		'
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	383		315.2		'
Other Comprehensive Income Loss Before Reclassifications Net Of Tax	-205.3	[1]	71.4	[2]	'
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	-4.5	[3]	-3.6	[4]	'
Other comprehensive income	-209.8		67.8		'
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	173.2		383		'
Employee Benefit Plans [Member]	'		'		'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'		'		'
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	-73.7		-80.1		'
Other Comprehensive Income Loss Before Reclassifications Net Of Tax	41.2	[1]	0	[2]	'
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	-6	[3]	6.4	[4]	'
Other comprehensive income	35.2		6.4		'
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	($38.50)		($73.70)		'
[1]	Net of tax benefit of $111.1 million for unrealized losses on fixed maturity securities and net of tax expense of $22.2 million for employee benefits.
[2]	Net of tax expense of $38.3 million for unrealized gains on fixed maturity securities and $0.2 million for employee benefits, respectively.
[3]	Net of tax benefit of $3.1 million for unrealized gains on fixed maturity securities and $3.2 million for employee benefits, respectively.
[4]	Net of tax benefit of $2.2 million for unrealized gains on fixed maturity securities and net of tax expense of $3.4 million for employee benefits.

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income (Parenthenticals) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Unrealized Gains (losses) on Available For Sale Securities [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Tax effect on other comprehensive income (loss) before reclassifications	($111.10)	$38.30
Reclassification from accumulated other comprehensive income current period tax	-3.1	-2.2
Employee Benefit Plans [Member]	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'
Tax effect on other comprehensive income (loss) before reclassifications	22.2	0.2
Reclassification from accumulated other comprehensive income current period tax	($3.20)	$3.40

Severance_Lease_Terminations_A2

Severance, Lease Terminations And Transition Costs (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Severance, Lease Terminations, And Transition Costs [Line Items]	'
Operating expenses	$442.60
Other Project Related Costs [Member]	'
Severance, Lease Terminations, And Transition Costs [Line Items]	'
Operating expenses	$2.30

Severance_Lease_Terminations_A3

Severance, Lease Terminations And Transition Costs (Severance, Lease Terminations, And Transition Costs) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Severance, Lease Terminations, And Transition Costs [Line Items]	'		'
Beginning Accrued Liability	$0.40	[1]	$2	[1]
Charged to Expense, Net	4.2		0
Expenditures	4.4		1.6
Ending Accrued Liability	0.2		0.4	[1]
Employee Severance [Member]	'		'
Severance, Lease Terminations, And Transition Costs [Line Items]	'		'
Beginning Accrued Liability	0.1	[1]	1	[1]
Charged to Expense, Net	2.9		0
Expenditures	2.8		0.9
Ending Accrued Liability	0.2		0.1	[1]
Contract Termination [Member]	'		'
Severance, Lease Terminations, And Transition Costs [Line Items]	'		'
Beginning Accrued Liability	0.3	[1]	1	[1]
Charged to Expense, Net	0		0
Expenditures	0.3		0.7
Ending Accrued Liability	0		0.3	[1]
Transition And Other Restructuring Costs [Member]	'		'
Severance, Lease Terminations, And Transition Costs [Line Items]	'		'
Beginning Accrued Liability	0	[1]	0	[1]
Charged to Expense, Net	1.3		0
Expenditures	1.3		0
Ending Accrued Liability	$0		$0	[1]
[1]	Amounts relate to restructuring charges implemented by the Company during 2011.

Quarterly_Financial_Informatio2

Quarterly Financial Information (Financial Information By Calendar Quarter) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Quarterly Financial Information [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Premiums	$528.60	$524.40	$535.10	$536.20	$533.80	$528.70	$548.10	$553.30	$2,124.30	$2,163.90	$2,153.30
Administrative fees	32	30.5	30.4	28.7	28.5	27.8	29.8	28.6	121.6	114.7	115.5
Net investment income	160.8	155.8	154.1	159.2	157.6	159.8	151.4	159.7	629.9	628.5	612.8
Net realized capital losses	-2.8	-8.7	-2.6	-1.6	-1.9	-2.6	-4	-0.2	-15.7	-8.7	-6.9
Total revenues	718.6	702	717	722.5	718	713.7	725.3	741.4	2,860.10	2,898.40	2,874.70
Benefits to policyholders	394.5	395	424.1	441.8	444.7	422.4	475.9	450	1,655.40	1,793	1,771.20
Net income	$65	$59	$57.70	$46.80	$38.40	$44.90	$20	$35.20	$228.50	$138.50	$136.70
Basic	$1.48	$1.33	$1.30	$1.05	$0.87	$1.02	$0.45	$0.79	$5.16	$3.13	$3.05
Diluted	$1.46	$1.32	$1.30	$1.05	$0.87	$1.01	$0.45	$0.79	$5.13	$3.12	$3.04