Stancorp Financial (SFG) Inactive 10-K26 Feb 152014 FY Annual reportFinancial data

Company Profile

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
Document And Entity Information (USD $)	Dec. 31, 2014	Feb. 13, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Entity Registrant Name	STANCORP FINANCIAL GROUP INC
Entity Central Index Key	1079577
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding		42,142,630
Entity Public Float			$2,727,485,312
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	SFG
Closing Stock Price			$64

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Premiums	$2,052.40	$2,124.30	$2,163.90
Administrative fees	130.8	121.6	114.7
Net investment income	600.9	629.9	628.5
Net capital losses:
Total other-than-temporary impairment losses on fixed maturity securities-available-for-sale	-1.2	-1.1	-3.2
All other net capital losses	-12.8	-14.6	-5.5
Total net capital losses	-14	-15.7	-8.7
Total revenues	2,770.10	2,860.10	2,898.40
Benefits and expenses:
Benefits to policyholders	1,582.20	1,655.40	1,793
Interest credited	164.6	176.4	171.3
Operating expenses	470.6	442.6	470.5
Commissions and bonuses	207.2	207.9	203.7
Premium taxes	31.5	35.3	37.5
Interest expense	31.8	34.4	39.9
Net increase in deferred acquisition costs, value of business acquired and other intangible assets	-4.7	-4.9	-0.9
Total benefits and expenses	2,483.20	2,547.10	2,715
Income before income taxes	286.9	313	183.4
Income taxes	67.6	84.5	44.9
Net income	$219.30	$228.50	$138.50
Net income per common share:
Basic	$5.10	$5.16	$3.13
Diluted	$5.05	$5.13	$3.12
Weighted-average common shares outstanding:
Basic	43,018,215	44,243,364	44,283,771
Diluted weighted-average common shares outstanding	43,455,136	44,527,405	44,359,891

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
StatementOfIncomeAndComprehensiveIncomeAbstract
Net income	$219.30		$228.50		$138.50
Unrealized gains on securities-available-for-sale:
Net unrealized capital gains on securities-available-for-sale	50.3	[1]	-205.3	[1]	71.4	[1]
Reclassification adjustment for net capital (gains) losses included in net income, net CF	-2	[2]	-4.5	[2]	-3.6	[2]
Employee benefit plans:
Prior service (cost) credit and net (losses) gains arising during the period, net	-70.4	[3]	41.2	[3]	0	[3]
Reclassification adjustment for amortization to net periodic pension cost, net	1.7	[4]	-6	[4]	6.4	[4]
Total other comprehensive income, net of tax	-20.4		-174.6		74.2
Comprehensive income	$198.90		$53.90		$212.70

[1]	Net of tax expense of $24.6 million, tax benefit of $111.1 million and tax expense of $38.3 million for 2014, 2013 and 2012, respectively.
[2]	Net of tax benefits of $1.1 million, $3.1 million and $2.2 million for 2014, 2013 and 2012, respectively.
[3]	Net of tax benefit of $37.9 million and tax expenses of $22.2 million and $0.2 million for 2014, 2013 and 2012, respectively.
[4]	Net of tax expense of $0.9 million, tax benefit of $3.2 million and taxexpense of $3.4 million for 2014, 2013 and 2012, respectively.
[4]

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee benefit plans, tax effect:
Prior service credit and net losses arising during the period, tax effect	$37.90	($22.20)	($0.20)
Other Comprehensive Income (Loss), Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost Recognized in Net Periodic Pension Cost, Tax Effect	0.9	-3.2	3.4
Other comprehensive income, tax effect:
Unrealized gains (losses) on fixed maturity securities, tax effect	24.6	-111.1	38.3
Reclassification adjustment for net capital gains included in net income, tax effect	($1.10)	($3.10)	($2.20)

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
ASSETS
Fixed maturity securities-available-for-sale (amortized cost of $7,390.0 and $6,811.9)	$7,773.70	$7,120.50
Commercial mortgage loans, net	5,321.10	5,405.10
Real estate, net	37	65.7
Other invested assets	320.9	196.5
Total investments	13,452.70	12,787.80
Cash and cash equivalents	251.1	379.3
Premiums and other receivables	118.4	118.2
Accrued investment income	108	106.8
Amounts recoverable from reinsurers	994.2	988.1
Deferred acquisition costs, value of business acquired and other intangible assets, net	381	371.3
Goodwill	36	36
Property and equipment, net	79.3	84.7
Other assets	129.4	127.9
Separate account assets	7,179.80	6,393.20
Total assets	22,729.90	21,393.30
Liabilities:
Future policy benefits and claims	5,832.30	5,846.90
Other policyholder funds	6,537.80	6,051.60
Deferred tax liabilities, net	63.1	64.7
Short-term debt	1.1	1.5
Long-term debt	503.9	551.9
Other liabilities	440.1	330.7
Separate account liabilities	7,179.80	6,393.20
Total liabilities	20,558.10	19,240.50
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; 42,077,825 and 44,126,389 shares issued and outstanding at December 31, 2014 and December 31, 2013, respectively	5.3	68
Accumulated other comprehensive income	114.3	134.7
Retained earnings	2,052.20	1,950.10
Total shareholders' equity	2,171.80	2,152.80
Total liabilities and shareholders' equity	$22,729.90	$21,393.30

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Consolidated Balance Sheets [Abstract]
Amortized cost of fixed maturity securities-available-for-sale	$7,390	$6,811.90
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	42,077,825	44,126,389
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	Total	Common Stock [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]
Balance at Dec. 31, 2011	$1,990.40	$82.40	$235.10	$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	134.7	1,950.10
Balance, shares at Dec. 31, 2013		44,126,389
Changes in Shareholders' Equity
Net income	219.3			219.3
Other comprehensive income, net of tax	-20.4		-20.4
Common stock:
Repurchased	-147	-84.5		-62.5
Shares repurchased		-2,383,175
Issued under share-based compensation plans, net	21.8	21.8
Issued under share-based compensation plans net, shares		334,611
Dividends declared on common stock	-54.7			-54.7
Balance at Dec. 31, 2014	$2,171.80	$5.30	$114.30	$2,052.20
Balance, shares at Dec. 31, 2014		42,077,825

Consolidated_Statements_Of_Cha1

Consolidated Statements Of Changes In Shareholders' Equity (Parentheticals) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements Of Changes In Shareholders' Equity [Abstract]
Dividend per share	$1.30	$1.10	$0.93

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating:
Net income	$219.30	$228.50	$138.50
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized capital losses	14	15.7	8.7
Depreciation and amortization	115.4	112.9	117
Deferral of acquisition costs, value of business acquired and other intangible assets, net	-80.1	-76.9	-71.4
Deferred income taxes	10.7	13.4	6.4
Changes in other assets and liabilities:
Receivables and accrued income	-7.5	-8.4	-24.5
Future policy benefits and claims	-15.8	23.8	149.6
Other, net	-17.8	-29.4	51.4
Net cash provided by operating activities	238.2	279.6	375.7
Investing:
Proceeds from sale, maturity, or repayment of fixed maturity securities-available-for-sale	797.2	1,017.90	964.5
Proceeds from sale or repayment of commercial mortgage loans	1,270.40	1,124.60	797.6
Proceeds from sale of real estate	20.1	22	13.2
Proceeds from sale or maturity of other investments	20.5	0.2	0
Acquisition of fixed maturity securities-available-for-sale	-1,406.20	-1,303.30	-1,269.40
Acquisition or origination of commercial mortgage loans	-1,194.70	-1,286.80	-1,194.60
Acquisition of real estate	-1.4	-0.9	-1.3
Acquisition of other invested assets	-112	-64.2	-59.7
Acquisition of property and equipment, net	-10.7	-13.8	-13.3
Net cash used in investing activities	-616.8	-504.3	-763
Financing:
Policyholder fund deposits	2,907.50	2,081.50	2,008.60
Policyholder fund withdrawals	-2,421.30	-1,561	-1,555.60
Repayment of debt	-47.1	0	-250
Issuance of debt, net of issuance costs	0	0	246.7
Issuance of common stock	14.3	52.6	10.9
Repurchases of common stock	-147	-82.3	-10
Dividends paid on common stock	-54.7	-48.5	-41.3
Other financing activity, net	-1.3	1	0.3
Net cash provided by financing activities	250.4	443.3	409.6
(Decrease) increase in cash and cash equivalents	-128.2	218.6	22.3
Cash and cash equivalents, beginning of period	379.3	160.7	138.4
Cash and cash equivalents, end of period	251.1	379.3	160.7
Cash paid during the period for [Abstract]
Interest	205.1	199.6	205.5
Income taxes	61.7	64.1	4.2
Non-cash transactions:
Real estate acquired through commercial mortgage loan foreclosure	4.4	11.4	16.8
Commercial mortgage loans originated on real estate sold	$0.60	$1.40	$0.80

Summary_Of_Significant_Account

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Summary Of Significant Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	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. Insurance Services contains two reportable product segments, Employee Benefits and Individual Disability. Asset Management is a separate reportable segment. 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”), Standard Management, Inc. (“Standard Management”) and StanCap Insurance Company, Inc. (“StanCap Insurance Company”).
	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, Puerto Rico and the Virgin Islands.
	The Standard Life Insurance Company of New York was organized in 2000 and is licensed to provide group and individual disability insurance, group life and AD&D insurance, group dental insurance and vision 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 business 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 registered investment adviser providing performance analysis, fund selection support, model portfolios and other investment advisory and investment management services.
	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.
	StanCap Insurance Company is a pure captive insurance company domiciled in Oregon. Effective September 30, 2014, StanCap Insurance Company entered into a reinsurance agreement with Standard to reinsure Standard’s group life and AD&D insurance business.
	Standard holds interests in tax-advantaged investments. These interests are accounted for under the equity method of accounting. The carrying value of these interests was $296.3 million and $192.4 million at December 31, 2014 and 2013, 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, the reserves for future policy benefits and claims, DAC, VOBA and other intangible assets, 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 the Company’s results of operations and financial condition.

	Investment Valuations
	Fixed Maturity Securities—Available-for-sale (“Fixed Maturity Securities”)
	Capital gains and losses for fixed maturity securities are recognized using the specific identification method. If the fair value of a fixed maturity security declines below its amortized cost, the Company assesses whether the decline is other than temporary.
	In the Company’s quarterly impairment analysis, management evaluates whether a decline in fair 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 it 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 the Company’s 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, the Company separates the OTTI of fixed maturity 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 (loss). The cost basis of the fixed maturity security is permanently adjusted to reflect the credit loss. Once an impairment has been recorded, the Company continues to review the OTTI securities for further potential impairment.
	The Company will continue to evaluate its holdings; however, the Company currently expects the fair values of its 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 fixed maturity securities, the Company utilizes certain information in order to determine the present value of expected cash flows discounted using pre-impairment yields. The information includes, but is 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 sheets. See “Note 9—Fair Value” for a detailed explanation of the valuation methods the Company uses to calculate the fair value of its 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 payment 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 agreement. 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 agreement 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 investments are recorded at the lower of cost or net realizable value. The Company depreciates real estate investments using the straight-line depreciation method with useful lives varying from 30 to 40 years. 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 is recorded to net capital losses, and the carrying value of the investment is adjusted to reflect the impairment. There were no impairments recorded on real estate investments for 2014, 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 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 has been recorded, the Company continues to review the investment for further potential impairment. Impairments recorded on Real Estate Owned were $5.2 million, $8.7 million and $3.0 million for 2014, 2013 and 2012 respectively.
Total real estate was $37.0 million at December 31, 2014, compared to $65.7 million at December 31, 2013. Accumulated depreciation for real estate totaled $12.0 million and $13.4 million at December 31, 2014 and 2013, respectively.

Other Invested Assets
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
The Company’s tax-advantaged investments are structured as limited partnerships and are accounted for under the equity method of accounting. The Company has purchased tax-advantaged investments opportunistically due to the higher risk-adjusted returns. The primary sources of investment return are tax credits and the tax benefits derived from operating losses, both of which may exhibit variability over the life of the investment. Tax credits received from these investments are reported in the Company’s consolidated statements of income as either a reduction of state premium taxes, or a reduction of income taxes, based on the nature of the credits. The Company’s share of the operating losses of the limited partnerships decreases the carrying value of the investments and is reported as a component of net investment income. If the net present value of expected future cash flows of a tax-advantaged investment is less than the current book value of the investment, 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 in the period in which it was determined to be impaired.

Derivative Instruments
In 2014, the Company began the use of interest rate swaps to reduce the risks from changes in interest rates, to manage interest rate exposures arising from asset and liability mismatches, and to protect the value of investments held on the consolidated balance sheets. The interest rate swaps used by the Company are designed to qualify for hedge accounting. Interest rate swaps are recognized as either other invested assets or other liabilities in the Company’s consolidated balance sheets and are reported at fair value. The accounting for an interest rate swap depends on whether it has been designated and qualifies as part of a hedging relationship and on the type of hedging relationship. To qualify for hedge accounting, the Company formally documents the risk management objective and strategy for undertaking the hedging transaction and the designation of the hedge as either a fair value hedge or a cash flow hedge at the inception of the hedging transaction. The documentation includes a description of how the interest rate swap is expected to hedge the designated risk related to specific assets or liabilities on its balance sheets, the method that will be used to prospectively and retrospectively assess the hedge effectiveness, the method that will be used to measure ineffectiveness and how this ineffectiveness will be accounted for.
An interest rate swap designated as part of a hedging relationship must be assessed as being highly effective in offsetting the designated risk of the hedged item. Hedge effectiveness is formally assessed at inception and periodically throughout the life of the designated hedging relationship, using qualitative and quantitative methods. Qualitative methods include comparison of critical terms of the interest rate swap to the hedged item. Quantitative methods include regression or other statistical analysis of changes in the fair value or cash flows associated with the hedge relationship.
Changes in the fair value of an interest rate swap designated as a fair value hedge, including amounts measured as ineffective, and changes in the fair value of the hedged item, are recognized in the consolidated statements of income as a component of net capital gains and losses each period. The gain or loss on the termination of a fair value hedge is recognized in the consolidated statements of income as a component of net capital gains and losses during the period in which the termination occurs. When interest rate swaps are used in hedge accounting relationships, periodic settlements are recorded in net investment income.
The gain or loss on the termination of an ineffective fair value hedge is reported in the consolidated statements of income as a component of net capital gains or losses. Additionally, when a hedged item is disposed, the Company will terminate the related derivative instrument and recognize the gain or loss on termination in the Company’s consolidated statements of income as a component of net capital gains or losses.
Index-based guarantees embedded in indexed annuities (“index-based interest guarantees”) and Standard & Poor’s (“S&P”) 500 Index call spread options (“S&P 500 Index options”) do not qualify for hedge accounting. 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 in interest credited.
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. Changes in the fair value of S&P 500 Index options are recorded in net investment income.
Cash settlement activity of derivative contracts is reported in the consolidated statements of cash flows as a component of proceeds from or acquisition of other invested assets.
In the consolidated balance sheets, the Company offsets fair value amounts recognized for interest rate swaps. See “Note 11—Derivative Financial Instruments.”

Policy Loans
Policy loans are stated at their aggregate unpaid principal balances and are secured by policy cash values.

Common Stock
In 2013, Standard became a member of the Federal Home Loan Bank of Seattle (“FHLB of Seattle”) and purchased the required common stock for membership and activity. The FHLB of Seattle common stock is carried at par value and accounted for under the cost method. The Company periodically evaluates the FHLB of Seattle common stock for OTTI. The Company’s determination of whether this investment is impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value. There were no impairments recorded on the common stock of FHLB of Seattle in 2014 or 2013. The Federal Home Loan Bank of Des Moines (“FHLB of Des Moines”) and the FHLB of Seattle have announced that they have entered into a definitive agreement to merge the two banks. The merger agreement has been unanimously approved by the boards of directors of both banks and by the Federal Housing Finance Agency (“FHFA”). The potential merger must be approved by the members of both banks through a voting process that is expected to take place in the first half of 2015. The Company does not expect the merger to have a material effect on its business, financial position, results of operations, or cash flows.

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 are 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 54% and 93% expected to be amortized by years 5 and 15, respectively. DAC for group annuity products is amortized over 10 years with approximately 76% 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 insurance business assumed from Minnesota Life Insurance Company (“Minnesota Life”) and a block of group disability and group life insurance 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 insurance products. However, the VOBA related to the TIAA transaction associated with an in-force block of group long term disability insurance 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, 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 increase or decrease 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 the Company’s 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 6.5 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)			2014		2013

Home office properties			$	139.4	$	136.9
Office furniture and equipment				48.6		47.9
Capitalized software				173		169.4
Leasehold improvements				14.9		13.9

	Property and equipment, gross			375.9		368.1
Less: accumulated depreciation				296.6		283.4

		Property and equipment, net	$	79.3	$	84.7


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 2014, 2013 and 2012 was $17.8 million, $19.9 million and $24.1 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 34.2%, 33.8% and 33.3% of the corporate headquarters in Portland, Oregon at December 31, 2014, 2013 and 2012, 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 insurance 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 $188.3 million and $186.1 million at December 31, 2014 and 2013, respectively, and premiums on deposit and experience rated liabilities totaling $187.0 million and $193.5 million at December 31, 2014 and 2013, 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 on the consolidated balance sheets. Experience rated refunds (“ERRs”) 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 interest paid on income tax liabilities as interest expense and income tax penalties incurred as an operating expense.

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. 2014-01, *Accounting for Investments in Qualified Affordable Housing Projects*
In January 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-01, Accounting for Investments in Qualified Affordable Housing Projects. This ASU permits entities to account for qualified affordable housing projects under the proportional amortization method (“PAM”) of accounting. Under PAM, the cost of the investments is amortized in each period in proportion to the tax credits and benefits of tax losses received in that period to total benefits to be received over the life of the investments and allows the amortization of the investments and the tax benefits to be recognized in income taxes on the consolidated statements of income.
ASU No. 2014-01 is effective for annual reporting periods and interim reporting periods within those annual reporting periods beginning after December 15, 2014. Early adoption is permitted. The Company is adopting this ASU effective January 1, 2015, which it expects will decrease the beginning balance of 2015 retained earnings between $15 million and $20 million. Based on the investments held at December 31, 2014, the Company estimates the adoption of the ASU will result in a decrease in net income by approximately $13 million for 2015. The adoption of this ASU will change the timing of the benefit realized in net income but will not change the cumulative total benefit to net income over the life of the investments.

ASU No. 2014-09, *Revenue from Contracts with Customers*
In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers. The main objective of ASU No. 2014-09 is to provide a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This ASU does not apply to insurance contracts, financial instruments, and various other topics within the FASB Accounting Standards Codification. The core principle of the revenue model is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services.
ASU No. 2014-09 is effective for annual reporting periods and interim reporting periods within those annual reporting periods beginning after December 15, 2016. Early adoption is not permitted. The Company’s revenue is primarily from insurance contracts and financial instruments; therefore, the Company does not expect this ASU to have a material effect on its results of operations.

ASU No. 2015-01, *Income Statement – Extraordinary and Unusual Items*
In January 2015, the FASB issued ASU No. 2015-01, Income Statement – Extraordinary and Unusual Items. The main objective of ASU No. 2015-01 is to eliminate from GAAP the concept of extraordinary items however, the requirement to disclose unusual and infrequent items still exists. Under this guidance, an entity will no longer segregate extraordinary items from the results of ordinary operations; separately present an extraordinary item on its income statement, net of tax, after income from continuing operations; and disclose income taxes and earnings-per-share data applicable to an extraordinary item. The ASU affects the reporting and disclosure requirements for an event that is unusual in nature or that occurs infrequently.
ASU No. 2015-01 is effective for annual reporting periods and interim reporting periods within those annual reporting periods beginning after December 15, 2015. Early adoption is permitted if guidance is applied as of the beginning of the annual reporting period of adoption. The Company does not expect this ASU to have a material effect on its results of operations or disclosures.

Net_Income_Per_Common_Share

Net Income Per Common Share	12 Months Ended
Net Income Per Common Share	Dec. 31, 2014
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 common shares outstanding. Net income per diluted common share was calculated using the treasury stock method and reflects the dilutive effects of stock awards and potential exercises of dilutive outstanding stock options. Diluted weighted-average common shares outstanding does not include stock options with an option exercise price greater than the average market price because they are antidilutive and inclusion would increase net income per diluted common 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)		2014			2013	2012

	Net income		$	219.3	$	228.5	$	138.5

	Basic weighted-average common shares outstanding			43,018,215		44,243,364		44,283,771
	Stock options			342,791		194,978		74,232
	Stock awards			94,130		89,063		1,888

	Diluted weighted-average common shares outstanding			43,455,136		44,527,405		44,359,891

	Net income per common share:
		Basic	$	5.1	$	5.16	$	3.13
		Diluted		5.05		5.13		3.12

	Antidilutive shares not included in net income per diluted common
		share calculation		50,236		292,750		2,220,045

ShareBased_Compensation

Share-Based Compensation	12 Months Ended
Share-Based Compensation	Dec. 31, 2014
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. Of the 7,000,000 shares of common stock authorized for the 2002 Plan, 2,694,980 shares or options for shares remain available for grant at December 31, 2014. Of the 3,500,000 shares authorized for the ESPP, 1,378,369 shares remain available for issuance at December 31, 2014.

	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)		2014			2013			2012

	Compensation cost	$		8.1		$	8.3		$	6.7
	Related income tax benefit			2.8			2.9			2.3


	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 per share 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, 2012			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


		Granted		151,060			64.18
		Exercised		-261,208			41.64
		Forfeited		-4,218			48.55
		Expired		---			---

	Outstanding, December 31, 2014			1,540,728		$	45.31			5.4		$	37,827,108


	Options outstanding and exercisable:
		Vested or expected to be vested, December 31, 2014		1,524,736		$	45.25			5.4		$	37,523,747
		Fully vested and exercisable, December 31, 2014		1,220,891			43.85			4.6			31,759,884


	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 per share 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,
		2014			2013			2012

	Dividend yield		1.78	%		2.25	%		2.36	%
Expected stock price volatility		43.15			45.86			47.3
Risk-free interest rate		1.81			1.31			1.02
Expected option lives		6.0 years			6.2 years			5.9 years


The weighted-average grant date fair value of options granted was $23.29, $16.15 and $13.73 for 2014, 2013 and 2012, respectively.
The total intrinsic value of the options exercised was $5.9 million, $14.4 million and $3.2 million for 2014, 2013 and 2012, respectively. The amount that the Company received from the exercise of stock options was $10.9 million, $50.2 million and $7.6 million for 2014, 2013 and 2012, 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 for both 2014 and 2013 and $1.1 million for 2012.
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, 2014, the total cost related to unvested option awards that had not yet been recognized in the financial statements was $5.5 million. This cost will be recognized over a weighted-average period of 2.4 years.

Stock Award Grants
The Company currently 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 1,059,828 shares available for issuance as stock award grants at December 31, 2014.
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 DateFair Value			Activity		Weighted-Average Grant DateFair Value

Unvested balance, January 1, 2012			---		$	---		190,968		$	44.05
	Granted		---					179,818
	Vested		---					-9,200
	Forfeited		---					-64,790

Unvested balance, December 31, 2012			---			---		296,796			43.14


	Granted		59,823					129,172
	Vested		---					-13,964
	Forfeited		-3,057					-114,722

Unvested balance, December 31, 2013			56,766			38.56		297,282			40.34


	Granted		48,294					77,634
	Vested		---					-54,076
	Forfeited		-685					-118,968

Unvested balance, December 31, 2014			104,375			63.54		201,872			48.41


RSUs
The Company grants annual RSUs to officers and senior officers of the Company. RSUs typically cliff vest three 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 withholding.
The Company granted 48,294 and 59,823 RSUs for 2014 and 2013, respectively. 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, 2014, the total compensation cost related to unvested RSUs that had not yet been recognized in the financial statements was $2.8 million. This cost will be recognized over a weighted-average remaining period of 1.7 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 the Company’s financial performance conditions, with a portion of the shares withheld to cover required tax withholding.
The Company granted 77,634 and 129,172 Performance Shares for 2014 and 2013, respectively.
The Company issued 8,846 and 9,899 shares of StanCorp common stock for 2014 and 2012, respectively. Due to timing of when performance shares vested, the Company did not issue shares for 2013.
The fair value of the Performance Shares is 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 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, $7.7 million in additional compensation cost would be recognized through 2016. Assuming that the target performance is achieved, this cost would be recognized over a weighted-average period of 1.4 years. The target payout is 50% of the maximum performance shares. Assuming that the target performance is achieved for each performance goal, $2.1 million in additional compensation cost would be recognized through 2016.

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 17,294, 20,099 and 9,489 shares of StanCorp common stock for 2014, 2013 and 2012, respectively, related to the vesting of the annual Director stock grant for 2013, 2012 and 2011. The weighted-average fair value per share for the shares issued was $45.74, $44.12 and $36.40 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.
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,
	2014			2013			2012

Dividend yield		1.80-1.84	%		1.69-2.44	%		2.38-3.06	%
Expected stock price volatility		21.78-22.40			17.43-17.58			27.80-49.09
Risk-free interest rate		0.03-0.06			0.07-0.11			0.06-0.13
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,
(Dollars in millions—except per share data)	2014			2013			2012

Weighted-average grant date fair value per share for ESPP offerings	$	6.52		$	4.16		$	9.02
Compensation cost		0.3			0.3			1.4
Related income tax benefit		0.1			0.1			0.5

Retirement_Benefits

Retirement Benefits	12 Months Ended
Retirement Benefits	Dec. 31, 2014
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)							2014			2013			2012

	Change in projected benefit obligation:
			Projected benefit obligation at beginning of the year					$	-408.4		$	-418.5		$	-371.6
			Service cost						-8.4			-10.2			-9.7
			Interest cost						-19.3			-16.7			-16.5
			Actuarial (loss) gain						-87.1			26			-29.7
			Benefits paid						12.2			11			9

				Projected benefit obligation at end of the year					-511			-408.4			-418.5

	Change in fair value of plan assets:
			Fair value of plan assets at beginning of the year						440.4			386			349.7
			Actual return on plan assets						28.8			65.4			35.4
			Employer contributions						15			---			10
			Benefits paid and estimated expenses						-12.3			-11			-9.1

				Fair value of plan assets at end of the year					471.9			440.4			386

						Funded status at end of the year		$	-39.1		$	32		$	-32.5


	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)	2014			2013			2012

	Projected benefit obligation	$	511		$	408.4		$	418.5
	Accumulated benefit obligation		471.9			374.2			386.5
	Fair value of plan assets		471.9			440.4			386


	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 loss (income):

			Years ended
			December 31,
	(In millions)		2014			2013			2012

	Net loss		$	90.6		$	31.4		$	78.3
	Prior service cost			1.9			2.3			2.7
		Total recognized in accumulated other comprehensive (income) loss	$	92.5		$	33.7		$	81


	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 2015 are $6.9 million and $0.4 million net of tax, respectively.
	The following table sets forth the components of net periodic benefit (credit) 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)							2014			2013			2012

	Components of net periodic benefit (credit) cost:
			Service cost					$	8.5		$	10.3		$	9.8
			Interest cost						19.3			16.7			16.5
		Expected return on plan assets						-33.4			-29.3			-26.5
		Amortization of prior service cost						0.6			0.6			0.6
		Amortization of net actuarial loss						0.7			9.9			8.3
				Net periodic benefit (credit) cost				-4.3			8.2			8.7

Other changes in plan assets and benefit obligation recognized
	in other comprehensive loss (income):
		Net loss (gain)						91.8			-62.2			20.9
		Amortization of prior service cost						-0.7			-0.6			-0.6
		Amortization of net actuarial loss						-0.7			-9.9			-8.3

				Total recognized in other comprehensive loss (income)				90.4			-72.7			12

					Total recognized in net periodic benefit (credit) cost and other
						comprehensive loss (income)	$	86.1		$	-64.5		$	20.7


Weighted-average assumptions:
	Assumptions used for net periodic benefit (credit) cost:
		Discount rate						4.75	%		4	%		4.5	%
		Expected return on plan assets						7.71			7.7			7.69
		Rate of compensation increase						3.5			3			3.25

	Assumptions used to determine benefit obligations:
		Discount rate						4	%		4.75	%		4	%
		Rate of compensation increase						3			3.5			3


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 made contributions to the employee pension plan of $15.0 million and $10.0 million in 2014 and 2012, respectively. The Company did not make any contributions to the employee pension plan in 2013. The Company is not obligated to make any contributions to its pension plans for 2015. In addition, no plan assets are expected to be returned to the Company in 2015.
The following table sets forth the expected benefit payments for the Company’s pension plans:

(In millions)		Amount

2015		$	13.5
2016			14.6
2017			15.8
2018			16.8
2019			18
2020-2024			111.1


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, 2014 and 2013. 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,
		2014			2014			2013
		Target			Actual			Actual

Asset Category:
	Equity securities		50	%		50.3	%		49	%
	Debt securities		50			49.7			51

	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 is 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 Stable asset fund is primarily invested in investment grade securities and commercial mortgage loans.
The following tables set forth the estimated fair values of pension plan assets and liabilities measured and recorded at fair value on a recurring basis:

							31-Dec-14
(In millions)							Total			Level 1			Level 2			Level 3

Assets:
	Equity securities:
		Pooled separate account funds:
			Large cap growth				$	47.3		$	47.3		$	---		$	---
			Large cap blend					74			74			---			---
			Large cap value					24.2			24.2			---			---
			Mid cap blend					71.5			71.5			---			---
			Foreign					20.3			20.3			---			---

				Total pooled separate account funds				237.3			237.3			---			---

	Debt securities:
			Stable asset fund					234.6			---			234.6			---

				Total			$	471.9		$	237.3		$	234.6		$	---


							31-Dec-13
(In millions)							Total			Level 1			Level 2			Level 3

Assets:
	Equity securities:
		Pooled separate account funds:
			Large cap growth				$	43		$	43		$	---		$	---
			Large cap blend					64.7			64.7			---			---
			Large cap value					21.7			21.7			---			---
			Mid cap blend					64.8			64.8			---			---
			Foreign					21.7			21.7			---			---

				Total pooled separate account funds				215.9			215.9			---			---

	Debt securities:
			Stable asset fund					224.5			---			224.5			---

				Total			$	440.4		$	215.9		$	224.5		$	---


There were no transfers into or from Level 1, 2 or 3 for 2014 and 2013.
As a result of inputs used during the current period to estimate the fair value of the stable asset fund, Plan management has categorized the stable asset fund as having Level 2 inputs at December 31, 2014. 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 2014, 2013 and 2012 were $10.7 million, $9.9 million and $9.9 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 $12.6 million and $11.6 million at December 31, 2014 and 2013, 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 2006, participation in the postretirement benefit plan was closed to new participants. An amendment announced in 2012 reduced future benefits for plan participants that did not retire by July 1, 2013.
The Company recognizes the funded status of the postretirement benefit plan as an asset or liability on the consolidated balance sheets. The funded status is measured as the difference between the fair value of the plan assets and the accumulated postretirement 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)							2014			2013			2012

Change in accumulated postretirement benefit obligation:
		Accumulated postretirement benefit obligation at beginning of the year					$	-17.6		$	-23.9		$	-41
		Service cost						---			---			-1
		Interest cost						-0.8			-1.1			-1.8
		Plan amendments						---			0.8			25.2
		Actuarial (loss) gain						-7.3			5.2			-5.9
		Benefits paid						1			1.4			0.6

			Accumulated postretirement benefit obligation at end of the year					-24.7			-17.6			-23.9

Change in fair value of postretirement plan assets:
		Fair value of plan assets at beginning of the year						19.3			21.6			20.7
		Actual return on plan assets						2			-1.6			1.2
		Employer contributions						0.9			0.7			0.3
		Benefits paid and estimated expenses						-1			-1.4			-0.6

			Fair value of plan assets at end of the year					21.2			19.3			21.6

					Funded status at end of the year		$	-3.5		$	1.7		$	-2.3


The gains and losses, and prior service costs or credits excluded from the projected postretirement benefit obligation are recognized as a component of accumulated other comprehensive loss (income), net of tax.
The following table sets forth the amounts recognized in accumulated other comprehensive loss (income):

		Years ended
		December 31,
(In millions)		2014			2013			2012

Net loss (gain)		$	2.9		$	-1		$	5.1
Prior service credit			---			---			-17.1

	Total recognized in accumulated other comprehensive loss (income)	$	2.9		$	-1		$	-12


In 2015, no estimated prior service credit or net loss (gain) for the postretirement benefit plan will be amortized from accumulated other comprehensive loss (income) into net periodic benefit cost. The projected discounted cash flow obligation for the postretirement benefit plan was $24.7 million and $17.6 million at December 31, 2014 and 2013, respectively.
The following table sets forth the assumed health care cost trend rates for next year:

	Years ended
	December 31,
	2014			2013

Medical		6.9	%		7.1	%
Prescriptions		7.2			7.5
HMO (Blended)		5.7			6
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						2.8			-2.3


The following table sets forth the components of net periodic benefit cost (credit), 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 (credit) cost and the postretirement benefit obligations:

							Years ended
							December 31,
(Dollars in millions)							2014			2013			2012

Components of net periodic benefit (credit) cost:
		Service cost					$	---		$	---		$	1
		Interest cost						0.8			1			1.8
		Expected return on plan assets						-0.8			-0.8			-0.8
		Amortization of prior service cost						---			-26.3			-0.4
		Amortization of net actuarial loss						---			5.7			---
				Net periodic benefit (credit) cost				---			-20.4			1.6

Other changes in plan assets and benefit obligation recognized
	in other comprehensive (income) loss:
		Net (gain) loss						-5.9			-3.3			5.5
		Prior service credit						---			---			-25.2
		Amortization of prior service credit						---			26.3			0.4
		Amortization of net actuarial loss						---			-5.8			---

				Total recognized in other comprehensive (income) loss				-5.9			17.2			-19.3

					Total recognized in net periodic benefit (credit) cost and other
						comprehensive (income) loss	$	-5.9		$	-3.2		$	-17.7


Weighted-average assumptions:
	Assumptions used for net periodic benefit (credit) cost:
		Discount rate						4.8	%		4	%		4.5	%
		Expected return on plan assets						4.2			4.2			4.2

	Assumptions used to determine benefit obligations:
		Discount rate						4.1	%		4.8	%		4	%


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. Assumptions for rate of compensation increase were not applicable in determining benefit obligations or net periodic benefit costs for 2014, 2013 and 2012 due to the curtailment of group term life insurance benefit as of December 31, 2011.
The Company contributed $0.5 million, $0.4 million and $0.3 million to fund the postretirement benefit plan in 2014, 2013 and 2012, respectively. The Company expects to make contributions of $0.8 million to its postretirement benefit plan in 2015. No plan assets are expected to be returned to the Company in 2015.
The following table sets forth the expected benefit payments for the Company’s postretirement benefit plan:

(In millions)		Amount

2015		$	1.5
2016			1.5
2017			1.4
2018			1.4
2019			1.3
2020-2024			6.4


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,
			2014			2014			2013
			Target			Actual			Actual

Asset category:
	Debt securities			95	%		96.7	%		96.2	%
	Cash and cash equivalents			5			3.3			3.8

		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 and corporate bond holdings at December 31, 2014, the municipal and corporate bonds were valued using Level 2 measurements.
The following tables set forth the estimated fair values of assets measured and recorded at fair value on a recurring basis:

							31-Dec-14
(In millions)							Total			Level 1			Level 2			Level 3

Assets:
	Debt securities:
		Municipal bonds					$	17.9		$	---		$	17.9		$	---
		Corporate bonds						2.6			---			2.6			---
	Cash and cash equivalents							0.7			0.7			---			---

			Total				$	21.2		$	0.7		$	20.5		$	---


							31-Dec-13
(In millions)								Total			Level 1		Level 2			Level 3

Assets:
	Debt securities:
		Municipal bonds					$	16.8		$	---		$	16.8		$	---
		Corporate bond						1.8			---			1.8			---
	Cash and cash equivalents							0.7			0.7			---			---

			Total				$	19.3		$	0.7		$	18.6		$	---


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 consolidated balance sheets. The unfunded status was $42.8 million and $31.1 million at December 31, 2014 and 2013, respectively. Expenses were $3.9 million, $3.1 million and $1.9 million for 2014, 2013 and 2012, 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 $11.7 million, $5.7 million and $4.7 million at December 31, 2014, 2013 and 2012, respectively.

Segments

Segments	12 Months Ended
Segments	Dec. 31, 2014
Segments [Abstract]
Segments	5. SEGMENTS
	The Company collectively views and operates its businesses as Insurance Services and Asset Management. Insurance Services contains two reportable product segments, Employee Benefits and Individual Disability. 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 is a separate reportable segment. Asset Management provides investment and asset management products and 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, origination and servicing of fixed-rate commercial mortgage loans, individual fixed and indexed 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 primarily related to the impairment or the disposition of the Company’s invested assets and adjustments made in consolidation. Resources are allocated and performance is evaluated at the segment level. 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 fees charged by Asset Management 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)	2014			2013			2012

	Intersegment administrative fees	$	19.3		$	18.6		$	17.9


	The following table sets forth premiums, administrative fees and net investment income by major product line or category within each of the Company’s segments:

							Years ended
							December 31,
	(In millions)						2014			2013		2012

	Premiums:
		Insurance Services:
			Group life and AD&D				$	808.6		$	849.7	$	883.7
			Group long term disability					753.8			783		801.4
			Group short term disability					219			229		212.6
			Group other					79			78.3		78.9
			Experience rated refunds					-17.6			-13.1		4
				Total Employee Benefits				1,842.80			1,926.90		1,980.60
				Individual Disability				199.1			190.5		176.6
					Total Insurance Services premiums			2,041.90			2,117.40		2,157.20
		Asset Management:
				Retirement plans				1.7			2.2		1.9
				Individual annuities				8.8			4.7		4.8
					Total Asset Management premiums			10.5			6.9		6.7
						Total premiums	$	2,052.40		$	2,124.30	$	2,163.90

	Administrative fees:
		Insurance Services:
				Employee Benefits			$	16.5		$	15.1	$	13.7
				Individual Disability				0.2			0.2		0.2
					Total Insurance Services administrative fees			16.7			15.3		13.9
		Asset Management:
				Retirement plans				99.7			93.3		88
				Other financial services businesses				33.7			31.6		30.8
					Total Asset Management administrative fees			133.4			124.9		118.8
		Other administrative fees						-19.3			-18.6		-18
						Total administrative fees	$	130.8		$	121.6	$	114.7

	Net investment income:
		Insurance Services:
				Employee Benefits			$	247.4		$	267.8	$	286
				Individual Disability				52.1			52.8		53.7
					Total Insurance Services net investment income			299.5			320.6		339.7
		Asset Management:
				Retirement plans				113.2			103.2		94.9
				Individual annuities				155.9			177.2		170.6
				Other financial services businesses				14.2			12.8		13.1
					Total Asset Management net investment income			283.3			293.2		278.6
		Other net investment income						18.1			16.1		10.2
						Total net investment income	$	600.9		$	629.9	$	628.5


	The following tables set forth select segment information:

					Year ended
				31-Dec-14
										Total
				Employee			Individual			Insurance		Asset
(In millions)				Benefits			Disability			Services		Management		Other		Total

Revenues:
	Premiums			$	1,842.80		$	199.1		$	2,041.90	$	10.5	$	---	$	2,052.40
	Administrative fees				16.5			0.2			16.7		133.4		-19.3		130.8
	Net investment income				247.4			52.1			299.5		283.3		18.1		600.9
	Net capital losses				---			---			---		---		-14		-14
			Total revenues		2,106.70			251.4			2,358.10		427.2		-15.2		2,770.10

Benefits and expenses:
	Benefits to policyholders				1,431.40			130			1,561.40		20.8		---		1,582.20
	Interest credited				2.6			---			2.6		162		---		164.6
	Operating expenses				321.4			27.8			349.2		122.7		-1.3		470.6
	Commissions and bonuses				122.6			48			170.6		36.6		---		207.2
	Premium taxes				27.9			3.6			31.5		---		---		31.5
	Interest expense				---			---			---		---		31.8		31.8
	Net (increase) decrease in DAC,
		VOBA and other intangible assets			-1			-10.9			-11.9		7.2		---		-4.7
			Total benefits and expenses		1,904.90			198.5			2,103.40		349.3		30.5		2,483.20
Income (loss) before income taxes				$	201.8		$	52.9		$	254.7	$	77.9	$	-45.7	$	286.9
Total assets				$	5,952.50		$	2,399.50		$	8,352.00	$	14,025.60	$	352.3	$	22,729.90


				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	$	---	$	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				---			---			---		---		-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		---		1,655.40
	Interest credited				4.3			---			4.3		172.1		---		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		---		207.9
	Premium taxes				31.3			3.9			35.2		0.1		---		35.3
	Interest expense				---			---			---		---		34.4		34.4
	Net decrease (increase) in DAC,
		VOBA and other intangible assets			1.9			-12.4			-10.5		5.6		---		-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	$	---	$	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				---			---			---		---		-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		---		1,793.00
	Interest credited				4.2			---			4.2		167.1		---		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		---		203.7
	Premium taxes				33.6			3.9			37.5		---		---		37.5
	Interest expense				---			---			---		---		39.9		39.9
	Net decrease (increase) in DAC,
		VOBA and other intangible assets			6.9			-12.7			-5.8		4.9		---		-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

Parent_Holding_Company_Condens

Parent Holding Company Condensed Financial Information	12 Months Ended
Parent Holding Company Condensed Financial Information	Dec. 31, 2014
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)						2014			2013			2012
	Revenues:
		Net investment income					$	12.9		$	13.2		$	5
		Net capital (losses) gains						-0.8			0.2			0.1

					Total revenues			12.1			13.4			5.1

	Expenses:
		Interest expense						31.7			34.2			39.7
		Operating expenses						0.5			0.9			4.5

					Total expenses			32.2			35.1			44.2


	Loss before income taxes and equity in net income of subsidiaries							-20.1			-21.7			-39.1
	Income tax benefit							-6.1			-7.7			-14.2
	Equity in net income of subsidiaries							233.3			242.5			163.4

	Net income							219.3			228.5			138.5

	Other comprehensive (loss) income, net of tax:
		Other comprehensive (loss) income from parent						-57.5			47			1.7
		Other comprehensive income (loss) from subsidiaries						37.1			-221.6			72.5
			Total other comprehensive (loss) income, net of tax					-20.4			-174.6			74.2

	Comprehensive income						$	198.9		$	53.9		$	212.7


	The following table sets forth StanCorp’s condensed balance sheets:

						December 31,
	(In millions)					2014			2013
	A S S E T S

	Cash and cash equivalents					$	70.5		$	125.2
	Investment in subsidiaries						2,317.90			2,252.90
	Receivable from subsidiaries						0.9			1.5
	Subordinated surplus note ("Surplus Note") receivable from subsidiary						250			250
	Other assets						77.9			80.3

					Total assets	$	2,717.20		$	2,709.90

	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				$	502.9		$	550
		Other liabilities					42.5			7.1

			Total liabilities				545.4			557.1


	Shareholders’ equity:
			Total shareholders' equity				2,171.80			2,152.80

					Total liabilities and shareholders’ equity	$	2,717.20		$	2,709.90


The following table sets forth StanCorp’s condensed statements of cash flows:

					Years ended
					December 31,
(In millions)					2014				2013		2012

Operating:
	Net income				$	219.3		$	228.5		$	138.5
	Adjustments to reconcile net income to net cash provided by operating activities:
		Equity in net income of subsidiaries				-233.3			-242.5			-163.4
		Dividends received from consolidated subsidiaries				423			147			328.7
		Changes in operating assets and liabilities				-13.4			23.7			-2.5

				Net cash provided by operating activities		395.6			156.7			301.3

Investing:
	Capital contributions to subsidiaries					-240.3			-0.7			-14.5
	Return of capital from subsidiaries					27			7.8			7.3
	Surplus note receivable from subsidiary					---			---			-250
	Receivables from subsidiaries, net					0.3			-0.3			3.4
	Investment securities and other					-2.8			0.2			1.4

				Net cash (used in) provided by investing activities		-215.8			7			-252.4

Financing:
	Issuance and repurchase of common stock, net					-132.7			-29.7			0.9
	Repayment of debt					-47.1			---			-250
	Issuance of debt, net of issuance costs					---			---			246.7
	Dividends paid on common stock					-54.7			-48.5			-41.3

				Net cash used in financing activities		-234.5			-78.2			-43.7

(Decrease) increase in cash and cash equivalents						-54.7			85.5			5.2
Cash and cash equivalents, beginning of year						125.2			39.7			34.5

Cash and cash equivalents, end of year					$	70.5		$	125.2		$	39.7

Income_Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2014
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)		2014			2013			2012

	Current		$	56.9		$	71.1		$	38.5
	Deferred			10.7			13.4			6.4

		Total income tax provision	$	67.6		$	84.5		$	44.9


	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)			2014			2013			2012

	Tax at federal corporate rate of 35%			$	100.4		$	109.6		$	64.2
	(Decrease) increase in rate resulting from:
		Tax exempt interest			---			---			-0.1
		Dividends received deduction			-4.4			-3.6			-3.6
		State income taxes, net of federal benefit			2.2			1.3			0.2
		Federal tax credits			-33.7			-24.9			-17.4
		Other			3.1			2.1			1.6

			Total income tax provision	$	67.6		$	84.5		$	44.9


	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)				2014			2013			2012

	Policyholder liabilities				$	9.6		$	1.2		$	1.8
	Compensation and benefit plans					49.9			12.6			44
	Loss carryforwards					46.6			49.7			51.7
	Investments					30.4			45.6			35.8
	Other					1.3			3.5			2.2

		Total deferred tax assets				137.8			112.6			135.5
	Less: valuation allowances					-9.5			-9.5			-3.1

			Net deferred tax assets			128.3			103.1			132.4

	Net unrealized capital gains					116.8			95.7			210
	Capitalized software					5.6			6.8			8.3
	Deferred policy acquisition costs					67			63.5			59.7
	Intangible assets					---			0.9			2
	Other					2			0.9			0.5

		Total deferred tax liabilities				191.4			167.8			280.5

			Net deferred tax liability		$	-63.1		$	-64.7		$	-148.1


	The Company is carrying forward net operating losses (“NOLs”) of $54 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 2024 to 2034. In addition, the Company is carrying forward a $46 million federal NOLs 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 NOLs carryforward will expire between 2020 and 2025.
	Realization of the Company’s NOLs 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 $13.2 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 NOLs carryforwards will not be realized. As such, the Company has provided a valuation allowance of $8.4 million at December 31, 2014 on the deferred tax assets relating to these assets. The Company also has an additional $1.1 million in valuation allowances for other assets that are not state and local NOLs. 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 2034.
	As of December 31, 2014, the Company is subject to examination by the IRS for the years 2011 through 2014.
	The Company did not have any material unrecognized tax benefits at December 31, 2014 and 2013. The Company records interest paid on income tax liabilities as interest expense and income tax penalties incurred as an operating expense. See “Note 1—Summary of Significant Accounting Policies—Income Taxes.”

Goodwill

Goodwill	12 Months Ended
Goodwill	Dec. 31, 2014
Goodwill [Abstract]
Goodwill	8. GOODWILL
Goodwill	Goodwill is related to Asset Management and totaled $36.0 million at both December 31, 2014 and 2013. 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, 2014.

Fair_Value

Fair Value	12 Months Ended
Fair Value	Dec. 31, 2014
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 uses prices or other relevant information generated by market transactions involving identical or comparable assets or liabilities.
	The income approach 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 carrying value and the estimated fair value of each financial instrument:

							31-Dec-14
							Carrying			Fair
	(In millions)						Value			Value			Level 1			Level 2			Level 3

	Assets:
		Fixed maturity securities:
			Corporate bonds				$	7,272.60		$	7,272.60		$	---		$	7,183.60		$	89
			U.S. government and agency bonds					300.1			300.1			---			300.1			---
			U.S. state and political subdivision bonds					136.1			136.1			---			136.1			---
			Foreign government bonds					64.9			64.9			---			64.9			---
				Total fixed maturity securities			$	7,773.70		$	7,773.70		$	---		$	7,684.70		$	89

		Commercial mortgage loans, net					$	5,321.10		$	6,021.50		$	---		$	---		$	6,021.50
		S&P 500 Index options						13.6			13.6			---			---			13.6
		Policy loans						2.2			2.2			---			---			2.2
		Separate account assets						7,179.80			7,179.80			7,066.40			113.4			---

	Liabilities:
		Other policyholder funds,
			investment-type contracts				$	5,961.10		$	6,232.50		$	---		$	---		$	6,232.50
		Index-based interest guarantees						77			77			---			---			77
		Interest rate swaps						4.7			4.7			---			4.7			---
		Short-term debt						1.1			1.5			---			1.5			---
		Long-term debt						503.9			538.4			---			538.4			---


							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		$	---		$	6,429.70		$	116
			U.S. government and agency bonds					353.2			353.2			---			353.2			---
			U.S. state and political subdivision bonds					140.3			140.3			---			140.3			---
			Foreign government bonds					65.5			65.5			---			65.5			---
			S&P 500 Index options					15.8			15.8			---			---			15.8
				Total fixed maturity securities			$	7,120.50		$	7,120.50		$	---		$	6,988.70		$	131.8

		Commercial mortgage loans, net					$	5,405.10		$	5,769.60		$	---		$	---		$	5,769.60
		Policy loans						2.5			2.5			---			---			2.5
		Separate account assets						6,393.20			6,393.20			6,249.20			144			---

	Liabilities:
		Other policyholder funds,
			investment-type contracts				$	5,469.80		$	5,632.70		$	---		$	---		$	5,632.70
		Index-based interest guarantees						67.6			67.6			---			---			67.6
		Short-term debt						1.5			1.9			---			1.9			---
		Long-term debt						551.9			553.6			---			553.6			---


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, 2014 and December 31, 2013, and trades occurring close to December 31, 2014 and December 31, 2013.

Financial Instruments Measured and Recorded at Fair Value
Fixed maturity securities, S&P 500 Index options, interest rate swaps and index-based interest guarantees are recorded at fair value on a recurring basis. In the Company’s consolidated statements of comprehensive income, unrealized gains and losses are reported in other comprehensive income (loss) for fixed maturity securities. In the Company’s consolidated statements of income, the change in fair value for S&P 500 Index options is reported in net investment income. For interest rate swaps that are designated as a fair value hedge, the change in the fair values of the interest rate swap and the hedged item are reported in net capital gains and losses. The fair value of interest rate swaps is determined through Level 2 inputs using quoted prices from an independent pricing service. The change in fair value for index-based interest guarantees is reported in interest credited.
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 to 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.

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 the 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 list of fixed maturity securities with characteristics that could indicate potential impairment. 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, 2014 or December 31, 2013.
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 discounted cash flow valuation model to determine the fair value of the interest rate swaps. The inputs used in the model are observable in the market. The interest rate swaps qualify as Level 2 under the fair value hierarchy since their valuation is based on a model for which all significant assumptions are observable in the market.
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 sheets.
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 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 are measured at fair value on a nonrecurring basis using significant unobservable Level 3 inputs and are sensitive to a number of variables. Real Estate Owned is 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 valuations of assets and liabilities measured and recorded at fair value:

							31-Dec-14					31-Dec-13
							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		$	13.6		(a)		$	15.8		(a)
Index-based interest			Discounted cash		Expected future		$	77		1% - 3%		$	67.6		1% - 6%
	guarantees		flow		option purchase
					Various assumptions					(b)					(b)
			Black-Scholes option pricing model		Various assumptions					(a)					(a)
Commercial mortgage loans			Appraisals		Reduction on appraisal		$	56		0% - 37%		$	68.7		0% - 13%
			Cash flows		Capitalization rate (c)					7% - 16%					7% - 16%
Real Estate Owned			Appraisals		Reduction on appraisal		$	10.3		0% - 11%		$	35.2		0% - 53%


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, 2014 and December 31, 2013.
Capitalization rates are used as an internal analysis in converting the underlying property 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, 2014
			Assets															Liabilities
						U.S.			U.S. State									Index-
						Government			and Political			S&P 500						Based
			Corporate			and Agency			Subdivision			Index			Total			Interest
(In millions)			Bonds			Bonds			Bonds			Options			Assets			Guarantees

Beginning balance			$	116		$	---		$	---		$	15.8		$	131.8		$	67.6
Total realized/unrealized gains (losses):
	Included in net income			---			---			---			8.6			8.6			7.2
	Included in other comprehensive income (loss)			-3.8			---			---			---			-3.8			---
Purchases, issuances, sales and settlements:
	Purchases			---			---			---			9.3			9.3			---
	Issuances			---			---			---			---			---			12.2
	Sales			---			---			---			---			---			---
	Settlements			---			---			---			-20.1			-20.1			-10
Transfers into Level 3				8.4			---			---			---			8.4			---
Transfers out of Level 3				-31.6			---			---			---			-31.6			---

Ending balance			$	89		$	---		$	---		$	13.6		$	102.6		$	77


			Year ended December 31, 2013
			Assets																Liabilities
						U.S.			U.S. State										Index-
						Government			and Political				S&P 500						Based
			Corporate			and Agency			Subdivision				Index			Total			Interest
(In millions)			Bonds			Bonds			Bonds				Options			Assets			Guarantees

Beginning balance			$	80.4		$	1.1		$	1.7			$	11.3		$	94.5		$	57.4
Total realized/unrealized gains (losses):
	Included in net income			---			---			---				14.4			14.4			9
	Included in other comprehensive income (loss)			6.2			---			---				---			6.2			---
Purchases, issuances, sales and settlements:
	Purchases			---			---			---				9.4			9.4			---
	Issuances			---			---			---				---			---			6
	Sales			---			---			---				---			---			---
	Settlements			---			---			---				-19.3			-19.3			-4.8
Transfers into Level 3				61.6			---			---				---			61.6			---
Transfers out of Level 3				-32.2			-1.1			-1.7				---			-35			---

Ending balance			$	116		$	---		$	---			$	15.8		$	131.8		$	67.6


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 from 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 2014 and 2013.

The following table sets forth the changes in unrealized gains (losses) included in net income relating to Level 3 assets and liabilities that the Company continued to hold:

		Years ended
		December 31,
(In millions)		2014			2013

Assets:
	S&P 500 Index options	$	4.3		$	6.4

Liabilities:
	Index-based interest guarantees	$	14		$	-12.9


Changes in the fair value of fixed maturity securities that are not designated as part of a hedging relationship are recorded to other comprehensive income. Changes in the fair value of the S&P 500 Index options are recorded to net investment income. Changes in the fair value of the index-based interest guarantees are recorded to interest credited and are sensitive to a number of variables and assumptions. 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 $4.0 million and $4.1 million for 2014 and 2013, respectively.
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, 2014 that the Company continued to hold:

		31-Dec-14
(In millions)		Total			Level 1			Level 2			Level 3

Commercial mortgage loans		$	56		$	---		$	---		$	56
Real Estate Owned			10.3			---			---			10.3

	Total assets measured at fair value on a nonrecurring basis	$	66.3		$	---		$	---		$	66.3


Commercial mortgage loans measured on a nonrecurring basis with a carrying amount of $74.2 million were written down to their fair value of $56.0 million, less selling costs, at December 31, 2014. The specific commercial mortgage loan loss allowance related to these commercial mortgage loans was $23.8 million at December 31, 2014. The Real Estate Owned measured on a nonrecurring basis as of December 31, 2014, and still held at December 31, 2014 had net capital losses totaling $1.2 million for 2014. 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, 2013 that the Company continued to hold:

		31-Dec-13
(In millions)		Total			Level 1			Level 2			Level 3

Commercial mortgage loans		$	68.7		$	---		$	---		$	68.7
Real Estate Owned			35.2			---			---			35.2

	Total assets measured at fair value on a nonrecurring basis	$	103.9		$	---		$	---		$	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. See “Note 10—Investments—Commercial Mortgage Loans” for further disclosures regarding the commercial mortgage loan loss allowance.

Investments

Investments	12 Months Ended
Investments	Dec. 31, 2014
Investments [Abstract]
Investments	10. INVESTMENTS
	Fixed Maturity Securities
	The following tables set forth the amortized costs, gross unrealized gains and losses and fair values of the Company’s fixed maturity securities:

			December 31,
			2014
			Amortized			Unrealized			Unrealized			Fair
	(In millions)		Cost			Gains			Losses			Value

	Corporate bonds		$	6,943.80		$	367.9		$	-39.1		$	7,272.60
	U.S. government and agency bonds			262			38.3			-0.2			300.1
	U.S. state and political subdivision bonds			125.8			10.4			-0.1			136.1
	Foreign government bonds			58.4			6.5			---			64.9

		Total fixed maturity securities	$	7,390.00		$	423.1		$	-39.4		$	7,773.70


			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			---			65.5
	S&P 500 Index options			15.8			---			---			15.8

		Total fixed maturity securities	$	6,811.90		$	385.8		$	-77.2		$	7,120.50


	The following table sets forth the amortized costs and fair values of the Company’s fixed maturity securities by contractual maturity:

			31-Dec-14						31-Dec-13
			Amortized			Fair			Amortized			Fair
	(In millions)		Cost			Value			Cost			Value


	Due in one year or less		$	649		$	658		$	486.2		$	495.1
	Due after one year through five years			3,060.80			3,215.40			2,974.50			3,168.90
	Due after five years through ten years			2,847.90			2,916.70			2,497.50			2,524.60
	Due after ten years			832.3			983.6			853.7			931.9

		Total fixed maturity securities	$	7,390.00		$	7,773.70		$	6,811.90		$	7,120.50


	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 3.5%, or $275.1 million, of the Company’s fixed maturity securities portfolio at December 31, 2014. At December 31, 2014, the Company did not have any direct exposure to sub-prime or Alt-A mortgages in its fixed maturity securities portfolio.

	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-14
					Total						Less than 12 months						12 or more months
	(Dollars in millions)				Number			Amount			Number			Amount			Number			Amount

	Unrealized losses:
			Corporate bonds			995		$	39.1			683		$	21.3			312		$	17.8
			U.S. government and agency bonds			5			0.2			---			---			5			0.2
			U.S. state and political subdivision bonds			4			0.1			---			---			4			0.1

				Total		1,004		$	39.4			683		$	21.3			321		$	18.1

	Fair market value of securities with
		unrealized losses:
		Corporate bonds			995		$	1,763.20			683		$	1,162.20			312		$	601
		U.S. government and agency bonds			5			6.4			---			---			5			6.4
		U.S. state and political subdivision bonds			4			6.9			---			---			4			6.9

			Total		1,004		$	1,776.50			683		$	1,162.20			321		$	614.3


				31-Dec-13
				Total						Less than 12 months						12 or more months
(Dollars in millions)				Number			Amount			Number			Amount			Number			Amount

Unrealized losses:
		Corporate bonds			908		$	76			848		$	66.3			60		$	9.7
		U.S. government and agency bonds			9			0.4			9			0.4			---			---
		U.S. state and political subdivision bonds			10			0.8			10			0.8			---			---

			Total		927		$	77.2			867		$	67.5			60		$	9.7

Fair market value of securities with
	unrealized losses:
		Corporate bonds			908		$	1,663.80			848		$	1,557.70			60		$	106.1
		U.S. government and agency bonds			9			16.9			9			16.9			---			---
		U.S. state and political subdivision bonds			10			15.4			10			15.4			---			---

			Total		927		$	1,696.10			867		$	1,590.00			60		$	106.1


The unrealized losses on the fixed maturity 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 fixed maturity securities to recover as the fixed maturity securities approach their maturity dates or sooner if market yields for such fixed maturity securities decline. The Company does not believe that any of the fixed maturity 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 OTTI for fixed maturity securities.

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, 2014, 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-14						31-Dec-13
(Dollars in millions)			Amount			Percent			Amount			Percent


Property type:
	Retail		$	2,627.10		49.4	%		$	2,629.20		48.6	%
	Office			1,013.40		19.1				982.4		18.2
	Industrial			1,001.50		18.8				1,008.70		18.7
	Commercial			213.6		4				218.6		4
	Hotel/motel			165.7		3.1				276.3		5.1
	Apartment and other			299.8		5.6				289.9		5.4

		Total commercial mortgage loans, net	$	5,321.10		100	%		$	5,405.10		100	%

Geographic region*:
	Pacific		$	1,914.60		36	%		$	1,910.10		35.3	%
	South Atlantic			1,065.50		20				1,090.00		20.2
	West South Central			676.9		12.7				672.8		12.4
	Mountain			606.5		11.4				611.4		11.3
	East North Central			466		8.8				473.8		8.8
	Middle Atlantic			215.3		4				223		4.1
	East South Central			188.7		3.6				166.6		3.1
	West North Central			140.1		2.6				186.9		3.5
	New England			47.5		0.9				70.5		1.3

		Total commercial mortgage loans, net	$	5,321.10		100	%		$	5,405.10		100	%

U.S. state:
	California		$	1,434.20		27	%		$	1,455.50		26.9	%
	Texas			623.4		11.7				618.8		11.5
	Florida			309.4		5.8				331.6		6.1
	Georgia			306.6		5.8				310.7		5.8
	Other states			2,647.50		49.7				2,688.50		49.7

		Total commercial mortgage loans, net	$	5,321.10		100	%		$	5,405.10		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. Negotiated reductions of principal are generally 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)			2014			2013

Commercial mortgage loan loss allowance:
Beginning balance			$	43.6		$	46.6
	Provision			7.1			15.9
	Charge-offs, net			-10.7			-18.9

		Ending balance	$	40		$	43.6

Specific loan loss allowance			$	23.8		$	25.9
General loan loss allowance				16.2			17.7

		Total commercial mortgage loan loss allowance	$	40		$	43.6


Changes in the commercial mortgage loan loss allowance can result from the number of commercial mortgage loans with a specific loan loss allowance and general loan loss allowance and the composition factors of the commercial mortgage loan portfolio. Changes in the provision and charge-offs can result from losses related to foreclosures, accepted deeds in lieu of foreclosure on commercial mortgage loans and other related charges associated with commercial mortgage loans in the commercial mortgage loan portfolio.

The following table sets forth the recorded investment in commercial mortgage loans:

			December 31,
(In millions)			2014			2013

Commercial mortgage loans collectively evaluated for impairment			$	5,255.20		$	5,334.40
Commercial mortgage loans individually evaluated for impairment				105.9			114.3
Commercial mortgage loan loss allowance				-40			-43.6

		Total commercial mortgage loans, net	$	5,321.10		$	5,405.10


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-14
												Hotel/						Apartment
(In millions)			Retail			Industrial			Office			Motel			Commercial			and Other			Total

Performing commercial mortgage
	loans		$	2,622.40		$	1,001.40		$	1,012.70		$	165.7		$	213.6		$	299.1		$	5,314.90
Nonperforming commercial
	mortgage loans			4.7			0.1			0.7			---			---			0.7			6.2

		Total commercial mortgage loans	$	2,627.10		$	1,001.50		$	1,013.40		$	165.7		$	213.6		$	299.8		$	5,321.10


			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			---			---			---			11.9

		Total commercial mortgage loans	$	2,629.20		$	1,008.70		$	982.4		$	276.3		$	218.6		$	289.9		$	5,405.10


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-14
									Unpaid						Amount on
						Recorded			Principal			Related			Nonaccrual
(In millions)						Investment			Balance			Allowance			Status

Impaired commercial mortgage loans:
	Without specific loan loss allowances:
		Retail				$	25		$	25		$	---		$	10.5
		Office					1.6			1.6			---			---
		Commercial					2.3			2.3			---			0.5
		Apartment and other					2.8			2.8			---			---
			Total impaired commercial mortgage loans without specific
				loan loss allowances			31.7			31.7			---			11

	With specific loan loss allowances:
		Retail					52.2			52.2			12.3			7.7
		Office					8.6			8.6			2.9			---
		Industrial					4.6			4.6			1.6			0.1
		Commercial					8.5			8.5			7			0.6
		Apartment and other					0.3			0.3			---			---
			Total impaired commercial mortgage loans with specific
				loan loss allowances			74.2			74.2			23.8			8.4

					Total impaired commercial mortgage loans	$	105.9		$	105.9		$	23.8		$	19.4


						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		$	---		$	7.6
		Office					3.9			3.9			---			1.5
		Industrial					1			1			---			---
		Commercial					1.8			1.8			---			---
		Apartment and other					3.8			3.8			---			---
			Total impaired commercial mortgage loans without specific
				loan loss allowances			26.6			26.6			---			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			---			---
			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


Changes in the carrying value of impaired commercial mortgage loans can result from a change in the number of commercial mortgage loans with a specific loan loss allowance. As of December 31, 2014 and December 31, 2013, 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-14
									Pre-			Post-
									Restructuring			Restructuring
						Number of			Recorded			Recorded
(Dollars in millions)						Loans			Investment			Investment

Troubled debt restructurings:
		Retail					45		$	42.7		$	40.9
		Office					3			1.4			1.2
		Industrial					4			3.1			3.4
		Commercial					2			3			3.2
			Total troubled debt restructurings				54		$	50.2		$	48.7


						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


There were no troubled debt restructurings identified in the previous 12 months that subsequently defaulted during 2014.

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)	2014			2013			2012

Average recorded investment	$	105.6		$	113.4		$	101.3


The amount of interest income recognized on impaired commercial mortgage loans was $5.3 million, $4.2 million and $4.1 million for 2014, 2013 and 2012, respectively. The cash received by the Company in payment of interest on impaired commercial mortgage loans was $4.8 million, $3.8 million and $4.0 million for 2014, 2013 and 2012, 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-14
																					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		$	0.2		$	2		$	4.8		$	7		$	-2.1		$	2,622.20		$	2,627.10
	Office			1.9			---			0.8			2.7			---			1,010.70			1,013.40
	Industrial			0.5			---			0.3			0.8			-0.2			1,000.90			1,001.50
	Hotel/motel			---			---			---			---			---			165.7			165.7
	Commercial			---			---			---			---			---			213.6			213.6
	Apartment and other			0.2			0.7			---			0.9			---			298.9			299.8

		Total commercial mortgage loans	$	2.8		$	2.7		$	5.9		$	11.4		$	-2.3		$	5,312.00		$	5,321.10


			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			---			3.7			5			-0.9			978.3			982.4
	Industrial			---			3.3			1.8			5.1			-0.9			1,004.50			1,008.70
	Hotel/motel			6.3			---			---			6.3			---			270			276.3
	Commercial			---			---			---			---			---			218.6			218.6
	Apartment and other			---			---			---			---			---			289.9			289.9

		Total commercial mortgage loans	$	10.4		$	3.6		$	11.6		$	25.6		$	-3.3		$	5,382.80		$	5,405.10


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 and totaled $5.2 million and $40.1 million at December 31, 2014 and 2013, respectively. Commercial mortgage loans that were at least 60 days past due totaled $8.6 million and $15.2 million at December 31, 2014 and 2013, 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 0.16% of the commercial mortgage loan portfolio at December 31, 2014, compared to 0.28% at December 31, 2013.

Net Investment Income
The following table sets forth net investment income summarized by investment type:

					Years ended
					December 31,
(In millions)						2014			2013		2012

Fixed maturity securities					$	296.4		$	303		$	316.8
Commercial mortgage loans						332.1			341.7			331.9
Real estate						1.1			-1.4			-1
S&P 500 Index options						8.6			14.4			7.8
Other						4.5			9			8.6

			Gross investment income			642.7			666.7			664.1
Investment expenses						-22.4			-22.9			-22.3
Tax-advantaged investment operating losses						-19.4			-13.9			-13.3

				Net investment income	$	600.9		$	629.9		$	628.5


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)				2014			2013			2012

Gains:
	Fixed maturity securities			$	5.9		$	9.8		$	10.8
	Commercial mortgage loans				2.4			2.4			1.5
	Real estate				2			3			1.3
	Other				---			0.2			0.6

		Gross capital gains			10.3			15.4			14.2

Losses:
	Fixed maturity securities				-2.8			-2.3			-5
	Provision for commercial mortgage loan losses				-7.1			-15.9			-13.4
	Real estate				-6.4			-9.6			-3.5
	Other				-8			-3.3			-1

		Gross capital losses			-24.3			-31.1			-22.9

			Net capital losses	$	-14		$	-15.7		$	-8.7


Securities Deposited as Collateral
Securities deposited for the benefit of policyholders in various states, in accordance with state regulations, amounted to $7.2 million and $7.4 million at December 31, 2014 and 2013, respectively.
Standard is a member of the FHLB of Seattle. Standard issues collateralized funding agreements to the FHLB of Seattle and invests the cash received from advances to support various spread-based businesses and enhance its asset-liability management. Membership also provides an additional funding source and access to financial services that can be used as an alternative source of liquidity. At December 31, 2014, Standard had $139.0 million outstanding under funding agreements with the FHLB of Seattle and pledged $174.4 million of commercial mortgage loans as collateral for its outstanding advances. Standard had no outstanding funding agreements or pledged collateral with the FHLB of Seattle at December 31, 2013. The FHLB of Des Moines and the FHLB of Seattle have announced that they have entered into a definitive agreement to merge the two banks. The merger agreement has been unanimously approved by the boards of directors of both banks and by the FHFA. The potential merger must be approved by the members of both banks through a voting process that is expected to take place in the first half of 2015. The Company does not expect the merger to have a material effect on our business, financial position, results of operations or cash flows.

Derivative_Financial_Instrumen

Derivative Financial Instruments	12 Months Ended
Derivative Financial Instruments	Dec. 31, 2014
Derivative Financial Instruments [Abstract]
Derivative Financial Instruments	11. DERIVATIVE FINANCIAL INSTRUMENTS
	The Company uses derivative financial instruments to mitigate business risks including interest rate risk exposure. The Company has the following derivatives on its consolidated balance sheets: interest rate swaps, index-based guarantees and S&P 500 Index options.

	Interest Rate Swaps
	In 2014, the Company began the use of interest rate swaps to reduce risks from changes in interest rates, to manage interest rate exposures arising from asset and liability mismatches, and to protect the value of investments held on the consolidated balance sheets. The interest rate swaps used by the Company are designed to qualify for hedge accounting. Therefore, recognized changes in the fair value of the interest rate swaps and the changes in fair value of the hedged items attributable to the hedged risk, are offset in net capital gains and losses. Valuations for interest rate swaps are sensitive to changes in the interest rate environment.
	Interest income, interest expense and fees related to interest rate swaps are recorded as a component of net investment income.
	Interest rate swaps are recognized as either other invested assets or other liabilities in the consolidated balance sheets and are reported at fair value. To qualify for hedge accounting, the Company formally documents the risk management objective and strategy for undertaking the hedging transaction and the designation of the hedge as either a fair value hedge or a cash flow hedge at the inception of the hedging transaction. Included in this documentation is how the interest rate swap is expected to hedge the designated risk related to specific assets or liabilities on the balance sheet as well as a description of the method that will be used to retrospectively and prospectively assess the hedge effectiveness, the method that will be used to measure ineffectiveness and how this ineffectiveness will be recorded.
	A derivative instrument designated as part of a hedging relationship must be assessed as being highly effective in offsetting the designated risk of the hedged item. Hedge effectiveness is formally assessed at inception and periodically throughout the life of the designated hedging relationship, using qualitative and quantitative methods. Qualitative methods include comparison of critical terms of the derivative to the hedged item. Quantitative methods include regression or other statistical analysis of changes in the fair value or cash flows associated with the hedge relationship.
	In the event a hedged item is disposed, the Company will terminate the related interest rate swap and recognize the gain or loss on termination in the consolidated statements of income.
	Cash settlement activity of derivative contracts is reported in the consolidated statements of cash flows as a component of proceeds from or acquisition of other invested assets.

	Index-based Interest Guarantees
	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. The index-based interest guarantees do not qualify for hedge accounting. 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 to 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.

	S&P 500 Index Options
	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 do not qualify for hedge accounting. 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. Changes in the fair value of the S&P 500 Index options are recorded to net investment income. The Company generally purchases two S&P 500 Index option contracts per month, which have expiry dates of one year from the date of purchase.
	Option premiums paid for the Company’s index option contracts were $9.3 million and $9.4 million for 2014 and 2013, respectively. The Company received $20.1 million and $19.3 million for options exercised in 2014 and 2013, respectively.

	The following table sets forth the fair value of the Company’s derivative assets and liabilities:

				December 31,
				2014						2013
				Notional			Fair			Notional			Fair
	(In millions)			Amount			Value			Amount			Value
	Qualifying Fair Value Hedging Instruments
	Liabilities:
		Other liabilities:
			Interest rate swaps	$	350		$	4.7		$	---		$	---

	Non-Qualifying Hedging Instruments
	Assets:
		Other invested assets
			S&P 500 Index options		418.2			13.6			350.5			15.8

	Liabilities:
		Other policyholder funds:
			Index-based interest guarantees		---	-1		77			---	-1		67.6


	(1) The underlying factors for index-based guarantees vary by contract and other criteria, such as floors and ceilings on rates and future payouts.

	The following table sets forth the gross amounts of derivative instruments recorded on the consolidated balance sheets and the collateral pledged related to the derivative instruments:

				December 31,
	(In millions)			2014			2013
	Offsetting of Interest Rate Swaps

	Interest rate swaps, liabilities			$	-5.1		$	---
	Interest rate swaps, assets				0.4			---

		Net interest rate swaps			-4.7			---
		Accrued interest payable			-2.2			---
		Collateral pledged			12.2			---

			Net amount	$	5.3		$	---


	The following table sets forth the amount of gains or losses recognized in the consolidated statements of income from the change in fair value of the Company’s derivative assets and liabilities:

				Years ended December 31,
	(In millions)			2014			2013			2012
	Qualifying Fair Value Hedging Instruments

	Net capital losses:
	Interest rate swaps		$	-4.7		$	---		$	---

Non-Qualifying Hedging Instruments

Net investment income:
	S&P 500 Index options			8.6			14.4			7.8

Interest credited:
	Index-based interest guarantees			-7.2			-9			-6.4

		Net (losses) gains	$	-3.3		$	5.4		$	1.4


Fluctuations in the fair value of the interest rate swaps are driven by changes in the interest rate environment. Fluctuations in the fair value of the S&P 500 Index options are related to the volatility of the S&P 500 Index. Changes in 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 $4.0 million and $4.1 million for 2014 and 2013, respectively.
The ineffective portion of derivatives accounted for using hedge accounting was not material to the results of operations of the Company for 2014 and 2013 and 2012.

Counterparty Credit Risk
Interest rate swaps
As the Company uses a central counterparty (“CCP”) to clear all of its interest rate swaps, the Company is only exposed to the default of the CCP. Transactions with the CCP require the Company to pledge initial and variation margin collateral. At December 31, 2014, the Company pledged $12.2 million of cash and cash equivalents on its consolidated balance sheets as collateral to the CCP.
S&P 500 Index options
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 4.5% 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 S&P 500 Index options and its maximum credit risk exposure related to these instruments:

			31-Dec-14
			Assets at			Maximum
(In millions)			Fair Value			Credit Risk

Counterparty:
	The Bank of New York Mellon		$	4.5		$	5.4
	Goldman Sachs			3.5			4.4
	Merrill Lynch International			5.6			9.3

		Total	$	13.6		$	19.1

Deferred_Acquisition_Costs_DAC

Deferred Acquisition Costs ("DAC"), Value Of Business Acquired ("VOBA") And Other Intangible Assets	12 Months Ended
	Dec. 31, 2014
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)			2014			2013			2012

	Carrying value at beginning 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 balance at beginning of year, net		371.3			346.5			344.9

	Deferred or acquired during year:
		DAC			80.1			76.9			71.4


			Total deferred or acquired during year		80.1			76.9			71.4

	Amortized during year:
		DAC			-62.3			-42.7			-60.9
		VOBA			-2.3			-3.3			-3
		Other intangible assets			-5.8			-6.1			-5.9

			Total amortized during year		-70.4			-52.1			-69.8

	Carrying value at end of year, net:
		DAC			336.9			319.1			284.9
		VOBA			17.8			20.1			23.4
		Other intangible assets			26.3			32.1			38.2

			Total carrying value at end of year, net	$	381		$	371.3		$	346.5


	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-14						31-Dec-13
	(Dollars in millions)	Amount			Percent			Amount			Percent

	DAC	$	82.4		24.5	%		$	80.1		25.1	%
	VOBA		3.7		20.8				4.3		21.4


	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 increase or decrease 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 decrease 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 an adjustment to VOBA as a result of unlocking in 2014. 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)	2014			2013			2012


	Decrease to DAC and VOBA	$	-3.2		$	-1.7		$	-1.7


	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 due to changes in underlying assumptions are not expected to be material.
	The accumulated amortization of VOBA was $71.0 million and $68.7 million at December 31, 2014 and 2013, respectively. The accumulated amortization of other intangible assets was $48.4 million and $42.6 million at December 31, 2014 and 2013, 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

2015	$	7.6
2016		6.1
2017		4.6
2018		4.3
2019		4.1

Liability_For_Unpaid_Claims_Cl

Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds	12 Months Ended
	Dec. 31, 2014
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 on 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)			2014			2013		2012

	Net balance at beginning of the year:
		Balance at beginning of the year, gross of reinsurance		$	4,021.90		$	4,005.90	$	3,857.00
		Less: reinsurance recoverable			-139.9			-128.6		-117.3

			Net balance at beginning of the year		3,882.00			3,877.30		3,739.70

	Incurred related to:
		Current year			1,033.10			1,081.70		1,140.30
		Prior year's interest			172.3			180.3		181.2
		Prior years			-117.4			-133.2		-79.8

			Total incurred		1,088.00			1,128.80		1,241.70

	Paid related to:
		Current year			-322.2			-345.9		-354.8
		Prior year			-780.9			-778.2		-749.3

			Total paid		-1,103.10			-1,124.10		-1,104.10

	Net balance at end of the year				3,866.90			3,882.00		3,877.30
		Plus: reinsurance recoverable			154.8			139.9		128.6

			Balance at end of the year, gross of reinsurance	$	4,021.70		$	4,021.90	$	4,005.90


	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)			2014			2013		2012

	Future policy benefits and claims			$	5,832.30		$	5,846.90	$	5,843.20
		Less: Group life reserves			-727.7			-751.7		-765.3
		Less: Individual life reserves			-596.3			-603.6		-600.9
		Less: Group and individual annuity reserves			-219.9			-220		-237.4
		Less: Individual disability active life reserves			-266.7			-249.7		-233.7

			Liability for unpaid claims and claim adjustment expenses	$	4,021.70		$	4,021.90	$	4,005.90


	The majority of the net liability balances are related to long term disability insurance 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 insurance reserves were not made in 2014, 2013 and 2012 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 2014, 2013 and 2012. 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)			2014			2013

	Retirement plan stable asset funds			$	2,104.40		$	1,954.10
	Individual fixed-rate annuity funds				2,383.60			2,541.70
	Investment only stable asset funds				610.9			326.1
	Indexed annuity funds				504			440.8
Other				934.9			788.9

	Total other policyholder funds		$	6,537.80		$	6,051.60


The primary components of other policyholder funds are retirement plan stable asset funds for which the Company provides recordkeeping services, individual fixed-rate annuity funds, investment only stable asset funds and indexed annuity funds. The remaining balance is comprised primarily of premiums on deposits, advanced premiums and experience-related liabilities.

Reinsurance

Reinsurance	12 Months Ended
Reinsurance	Dec. 31, 2014
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 for group disability insurance is $15,000 of monthly benefit per individual. The Company’s maximum retention limit for individual disability insurance is $7,500 of monthly benefit per individual.
	Standard maintains a strategic marketing alliance with Ameritas Life Insurance Corp. (“Ameritas”) that offers Standard’s policyholders 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 2014, 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, 2014, was $241.1 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 2014, 2013 and 2012. In addition to assuming risk, Standard provides product design, pricing, underwriting, legal support, claims management and other administrative services under the arrangement.
	Effective September 30, 2014, StanCap Insurance Company entered into a reinsurance agreement with Standard to reinsure Standard’s group life and AD&D business. This reinsurance agreement between StanCap Insurance Company and Standard replaced the yearly renewable term group life reinsurance agreement with Canada Life Assurance Company, which was terminated effective September 30, 2014. The intercompany transactions between Standard and StanCap Insurance Company are eliminated in consolidation.
	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 and is part of a catastrophe reinsurance pool with other insurance companies.
	This pool spreads catastrophe losses from group life and AD&D over 18 participating members. The annual fee paid by the Company to participate in the pool was less than $30,000 for 2014. As a member of the pool, the Company is exposed to maximum potential losses experienced by other participating members of up to $104.6 million for a single event for losses submitted by a single company and a maximum of $261.5 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. Through a combination of reinsurance and its participation in the catastrophe reinsurance pool, the Company has coverage of up to $484.7 million per catastrophic event. In February 2015, the Company was notified of the termination of the catastrophe reinsurance pool effective June 2015. The Company is exploring its options in the market for catastrophe reinsurance coverage.
	The Terrorism Risk Insurance Act of 2002 (“TRIA”), which has been extended through 2020, 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

	2014:00:00
	Life insurance in-force			$	306,566.00	$	6,239.80	$	51.5	$	300,377.70	---	%
	Premiums:
		Life insurance and annuities		$	854.6	$	46.3	$	---	$	808.3	---
		Accident and health insurance			1,231.50		80.2		92.8		1,244.10	7.5

			Total premiums	$	2,086.10	$	126.5	$	92.8	$	2,052.40	4.5
	2013:00:00
	Life insurance in-force			$	321,881.70	$	5,966.80	$	57.7	$	315,972.60	---	%
	Premiums:
		Life insurance and annuities		$	898.5	$	48.5	$	---	$	850	---
		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	---	%
	Premiums:
		Life insurance and annuities		$	937.9	$	51	$	---	$	886.9	---
		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

	Recoveries recognized under reinsurance agreements were $92.8 million, $79.8 million and $74.0 million for 2014, 2013 and 2012, respectively. Amounts recoverable from reinsurers were $994.2 million and $988.1 million at December 31, 2014 and 2013, respectively. Of these amounts, $781.4 million and $791.0 million for 2014 and 2013, respectively, were from the reinsurance transaction with Protective Life Insurance Company (“Protective Life”) effective January 1, 2001. Effective February 1, 2015, Protective Life was acquired by The Dai-ichi Life Insurance Company, Limited (“Dai-ichi Life”) and is a wholly-owned subsidiary of Dai-ichi Life. ”See “Note 15—Reinsurance of Blocks of Business.”

Reinsurance_Of_Blocks_Of_Busin

Reinsurance Of Blocks Of Business	12 Months Ended
Reinsurance Of Blocks Of Business	Dec. 31, 2014
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, 2014, was $562.3 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 the credit quality of Protective Life. Effective February 1, 2015, Protective Life was acquired by Dai-ichi Life and is a wholly-owned subsidiary of Dai-ichi Life. 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, 2014, was $190.1 million. Approximately $60.0 million in VOBA was recorded related to the reinsurance agreement.

Insurance_Information

Insurance Information	12 Months Ended
Insurance Information	Dec. 31, 2014
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⁾

	2014:00:00
	Employee Benefits			$	25.7	$	3,936.90	$	302.8	$	1,842.80	$	247.4	$	1,434.00	$	21.9	$	470.9
	Individual Disability				228.8		1,675.50		196.9		199.1		52.1		130		24		68.5

		Total Insurance
			Services		254.5		5,612.40		499.7		2,041.90		299.5		1,564.00		45.9		539.4
		Asset Management			82.4		219.9		6,038.10		10.5		283.3		182.8		21.4		166.5

			Total	$	336.9	$	5,832.30	$	6,537.80	$	2,052.40	$	582.8	$	1,746.80	$	67.3	$	705.9


	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


	(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
Regulatory Matters	Dec. 31, 2014
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 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 2014, 2013 or 2012.
	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, 2014, 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 $208.5 million and capital and surplus was $1.15 billion. Based upon Standard's results for 2014, the amount of ordinary dividends and other distributions available in 2015, without additional approval from the Oregon Insurance Division is $208.5 million. 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 was $195.1 million.
	During 2014 and 2013, Standard made distributions to StanCorp totaling $390.0 million and $130.0 million, respectively. The 2014 distributions included a $240 million extraordinary distribution that was used to capitalize StanCap Insurance Company. Effective September 30, 2014, StanCap Insurance Company entered into a reinsurance agreement with Standard to reinsure Standard’s group life and AD&D business. This reinsurance agreement between StanCap Insurance Company and Standard replaced the yearly renewable term group life reinsurance agreement with Canada Life Assurance Company, which was terminated effective September 30, 2014. As a result of the extraordinary distribution in 2014, future dividends will require approval from the Oregon Insurance Division through September 2015 and will be considered extraordinary.
	State insurance departments require insurance enterprises to adhere to minimum Risk-based Capital (“RBC”) requirements promulgated by the NAIC. At December 31, 2014 and 2013, the insurance subsidiaries’ capital and surplus 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 $149.6 million and $186.6 million at December 31, 2014 and 2013, respectively. At December 31, 2014, the capital and surplus of the Company’s insurance subsidiaries was approximately 445% of the Company Action Level RBC required by regulators, which was approximately 890% of the Authorized Control Level RBC required by the Company’s states of domicile. At December 31, 2013, the capital and surplus 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.

	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)		2014		2013

	Statutory capital and surplus		$	1,228.40	$	1,359.00

	Adjustments to reconcile to GAAP equity:
		Future policy benefits and other policyholder funds		276		325.8
		DAC, VOBA and other intangible assets		365.7		351.6
		Deferred tax liabilities		-245.6		-265.3
		Asset valuation reserve		106.2		127.5
		Valuation of investments		259.6		236.4
		Interest maintenance reserve		28.5		25.5
		Equity of StanCorp and its non-insurance subsidiaries		277.5		116.1
		Non-admitted assets		166.3		178.2
		Pension and postretirement benefit plans		-11.3		-6.6
		Capital lease obligations		-2.1		-3.4
		Surplus note		-250		-250
		Other, net		-27.4		-42

	GAAP equity		$	2,171.80	$	2,152.80


	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)		2014		2013		2012

	Statutory net income		$	213.4	$	198.5	$	131.5

	Adjustments to reconcile to GAAP net income:
		Future policy benefits and other policyholder funds		-24.3		11		26.4
		DAC and VOBA, net of amortization		9.2		9.4		5.5
		Deferred income taxes		-5.7		-13.5		-22.4
		Current income taxes		9.6		9.6		17.2
		Earnings of StanCorp and its non-insurance subsidiaries		8.9		-8.9		-23.8
		Deferred capital gains (interest maintenance reserve)		3		0.7		5
		Pension and postretirement benefit plans		-2.6		17.6		-1.7
		Share based compensation		---		-3.6		-5.4
		Investments		7.9		8.5		5.8
		Other, net		-0.1		-0.8		0.4

	GAAP net income		$	219.3	$	228.5	$	138.5

LongTerm_Debt

Long-Term Debt	12 Months Ended
Long-Term Debt	Dec. 31, 2014
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 (“Senior Notes’’), which mature on August 15, 2022. Interest is payable semi-annually on February 15 and August 15.
	The Company has $252.9 million of 6.90%, junior subordinated debentures (“Subordinated Debt”), which matures on June 1, 2067 and is non-callable prior to June 1, 2017. In the first quarter of 2014, the Company repurchased $47.1 million in principal amount of Subordinated Debt. The remaining 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)			2014		2013

	Long-term debt:
		Senior notes		$	250	$	250
		Subordinated debt			252.9		300
		Other long-term borrowings			1		1.9

			Total long-term debt	$	503.9	$	551.9

Commitments_And_Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2014
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, 2014. 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, 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, which 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, 2014, 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)

	2015	$	9.2
	2016		8.8
	2017		8.3
	2018		3.9
	2019		1.9
	Thereafter		1.3


	Total rent expense was $13.3 million, $13.7 million and $15.2 million for the years ended December 31, 2014, 2013 and 2012, 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)

	2015	$	7.3
	2016		5.3
	2017		2.6
	2018		2
	2019		1.4
	Thereafter		4.9


	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 of 5.00% Senior Notes and the $252.9 million of 6.90% Subordinated Debt. See “Note 18—Long-Term Debt” for additional information.
	At December 31, 2014, the Company had $62.6 million of commitments to fund tax-advantaged investment partnerships. The commitments are recorded as other liabilities on the Company’s consolidated balance sheets with a corresponding recognition to other invested assets.
	At December 31, 2014, the Company had $139.0 million outstanding under funding agreements with the FHLB of Seattle, with fixed interest rates ranging from 0.38% to 3.79% that mature in 1 to 15 years. The funding agreements with the FHLB of Seattle are recorded as other policyholder funds on the Company’s consolidated balance sheets. The FHLB of Des Moines and the FHLB of Seattle have announced that they have entered into a definitive agreement to merge the two banks. The merger agreement has been unanimously approved by the boards of directors of both banks and by the FHFA. The potential merger must be approved by the members of both banks through a voting process that is expected to take place in the first half of 2015. The Company does not expect the merger to have a material effect on our business, financial position, results of operations or cash flows.
	In the normal course of business, the Company commits to fund commercial mortgage loans generally up to 90 days in advance. At December 31, 2014, the Company had outstanding commitments to fund commercial mortgage loans totaling $134.8 million, with fixed interest rates ranging from 4.00% to 6.00%. 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
Accumulated Other Comprehensive Income	Dec. 31, 2014
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, 2013			$	383	$	-73.7	$	309.3

		Other comprehensive (loss) income, net of tax
			before reclassification adjustment⁽¹⁾		-205.3		41.2		-164.1
		Amounts reclassified from accumulated
			other comprehensive income, net of tax⁽²⁾		-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

		Other comprehensive income (loss), net of tax
			before reclassification adjustment⁽³⁾		50.3		-70.4		-20.1
		Amounts reclassified from accumulated
			other comprehensive income (loss), net of tax⁽⁴⁾		-2		1.7		-0.3
	Net other comprehensive income (loss), net of tax				48.3		-68.7		-20.4

	Balance, December 31, 2014			$	221.5	$	-107.2	$	114.3

	Net of tax benefit of $111.1 million for net unrealized losses on fixed maturity securities and net of tax expense of $22.2 million for employee benefits.
	Net of tax benefits of $3.1 million for net unrealized gains on fixed maturity securities and $3.2 million for employee benefits, respectively.
	Net of tax expense of $24.6 million for net unrealized gains on fixed maturity securities and net of tax benefit of $37.9 million for employee benefits.
	Net of tax benefit of $1.1 million for net unrealized gains on fixed maturity securities and net of tax expense of $0.9 million for employee benefits.

Severance_Lease_Terminations_A

Severance, Lease Terminations And Transition Costs	12 Months Ended
Severance, Lease Terminations And Transition Costs	Dec. 31, 2014
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 prior periods. In addition to severance, transition costs and lease terminations, the Company incurred $2.3 million in other project initiatives in 2013.
	The following tables set forth expenses incurred related to the expense management initiatives:

			Year ended December 31, 2014
			Beginning						Ending
			Accrued		Charged to				Accrued
	(In millions)		Liability		Expense, Net		Expenditures		Liability

	Severance		$	0.2	$	-0.2	$	---	$	---

		Total severance	$	0.2	$	-0.2	$	---	$	---


			Year 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			---		1.3		1.3		---
	Lease terminations			0.3		---		0.3		---

		Total severance, transition costs and lease terminations	$	0.4	$	4.2	$	4.4	$	0.2


	Amounts relate to restructuring charges implemented by the Company during 2011.

Subsequent_Events

Subsequent Events	12 Months Ended
Subsequent Events	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	22. SUBSEQUENT EVENTS
	In January 2015, StanCorp reached an agreement to sell certain assets of its private client wealth management business within StanCorp Investment Advisers to a third party. StanCorp expects the sale to be completed during the first half of 2015. StanCorp Investment Advisers will remain a wholly-owned subsidiary of StanCorp and will continue to provide performance analysis, fund selection support, model portfolios and investment management services to its retirement plan clients and subsidiaries of StanCorp. The assets under administration associated with the private client wealth management business totaled $884.4 million at December 31, 2014, which represents 3.3% of the Company’s total assets under administration. As a result of this sale, the Company does not expect a material gain or loss, nor a material impact to net income.

Quarterly_Financial_Informatio

Quarterly Financial Information	12 Months Ended
Quarterly Financial Information	Dec. 31, 2014
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:

			2014
	(In millions—except per share data)		4th Quarter		3rd Quarter		2nd Quarter		1st Quarter

	Premiums		$	515.8	$	507.3	$	519.2	$	510.1
	Administrative fees			33.8		32.8		32.6		31.6
	Net investment income			153.4		147.1		149.8		150.6
	Net capital losses			-7.2		-5.2		-0.5		-1.1

		Total revenues		695.8		682		701.1		691.2
	Benefits to policyholders			394.1		360.8		426.2		401.1
	Net income			56.2		71.1		41.9		50.1


	Net income per common share:
		Basic	$	1.33	$	1.66	$	0.97	$	1.14
		Diluted		1.32		1.65		0.96		1.13


			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

Summary_Of_Significant_Account1

Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2014
Summary Of Significant Accounting Policies [Abstract]
Organization, Principles Of Consolidation, And Basis Of Presentation	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. Insurance Services contains two reportable product segments, Employee Benefits and Individual Disability. Asset Management is a separate reportable segment. 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”), Standard Management, Inc. (“Standard Management”) and StanCap Insurance Company, Inc. (“StanCap Insurance Company”).
	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, Puerto Rico and the Virgin Islands.
	The Standard Life Insurance Company of New York was organized in 2000 and is licensed to provide group and individual disability insurance, group life and AD&D insurance, group dental insurance and vision 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 business 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 registered investment adviser providing performance analysis, fund selection support, model portfolios and other investment advisory and investment management services.
	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.
	StanCap Insurance Company is a pure captive insurance company domiciled in Oregon. Effective September 30, 2014, StanCap Insurance Company entered into a reinsurance agreement with Standard to reinsure Standard’s group life and AD&D insurance business.
	Standard holds interests in tax-advantaged investments. These interests are accounted for under the equity method of accounting. The carrying value of these interests was $296.3 million and $192.4 million at December 31, 2014 and 2013, 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, the reserves for future policy benefits and claims, DAC, VOBA and other intangible assets, 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 the Company’s 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”)
	Capital gains and losses for fixed maturity securities are recognized using the specific identification method. If the fair value of a fixed maturity security declines below its amortized cost, the Company assesses whether the decline is other than temporary.
	In the Company’s quarterly impairment analysis, management evaluates whether a decline in fair 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 it 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 the Company’s 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, the Company separates the OTTI of fixed maturity 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 (loss). The cost basis of the fixed maturity security is permanently adjusted to reflect the credit loss. Once an impairment has been recorded, the Company continues to review the OTTI securities for further potential impairment.
	The Company will continue to evaluate its holdings; however, the Company currently expects the fair values of its 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 fixed maturity securities, the Company utilizes certain information in order to determine the present value of expected cash flows discounted using pre-impairment yields. The information includes, but is 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 sheets. See “Note 9—Fair Value” for a detailed explanation of the valuation methods the Company uses to calculate the fair value of its 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 payment 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 agreement. 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 agreement 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 investments are recorded at the lower of cost or net realizable value. The Company depreciates real estate investments using the straight-line depreciation method with useful lives varying from 30 to 40 years. 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 is recorded to net capital losses, and the carrying value of the investment is adjusted to reflect the impairment. There were no impairments recorded on real estate investments for 2014, 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 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 has been recorded, the Company continues to review the investment for further potential impairment. Impairments recorded on Real Estate Owned were $5.2 million, $8.7 million and $3.0 million for 2014, 2013 and 2012 respectively.
All Other Invested Assets	Other Invested Assets
	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	Tax-advantaged Investments
	The Company’s tax-advantaged investments are structured as limited partnerships and are accounted for under the equity method of accounting. The Company has purchased tax-advantaged investments opportunistically due to the higher risk-adjusted returns. The primary sources of investment return are tax credits and the tax benefits derived from operating losses, both of which may exhibit variability over the life of the investment. Tax credits received from these investments are reported in the Company’s consolidated statements of income as either a reduction of state premium taxes, or a reduction of income taxes, based on the nature of the credits. The Company’s share of the operating losses of the limited partnerships decreases the carrying value of the investments and is reported as a component of net investment income. If the net present value of expected future cash flows of a tax-advantaged investment is less than the current book value of the investment, 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 in the period in which it was determined to be impaired.

DerivativesPolicyTextBlock	Derivative Instruments
	In 2014, the Company began the use of interest rate swaps to reduce the risks from changes in interest rates, to manage interest rate exposures arising from asset and liability mismatches, and to protect the value of investments held on the consolidated balance sheets. The interest rate swaps used by the Company are designed to qualify for hedge accounting. Interest rate swaps are recognized as either other invested assets or other liabilities in the Company’s consolidated balance sheets and are reported at fair value. The accounting for an interest rate swap depends on whether it has been designated and qualifies as part of a hedging relationship and on the type of hedging relationship. To qualify for hedge accounting, the Company formally documents the risk management objective and strategy for undertaking the hedging transaction and the designation of the hedge as either a fair value hedge or a cash flow hedge at the inception of the hedging transaction. The documentation includes a description of how the interest rate swap is expected to hedge the designated risk related to specific assets or liabilities on its balance sheets, the method that will be used to prospectively and retrospectively assess the hedge effectiveness, the method that will be used to measure ineffectiveness and how this ineffectiveness will be accounted for.
	An interest rate swap designated as part of a hedging relationship must be assessed as being highly effective in offsetting the designated risk of the hedged item. Hedge effectiveness is formally assessed at inception and periodically throughout the life of the designated hedging relationship, using qualitative and quantitative methods. Qualitative methods include comparison of critical terms of the interest rate swap to the hedged item. Quantitative methods include regression or other statistical analysis of changes in the fair value or cash flows associated with the hedge relationship.
	Changes in the fair value of an interest rate swap designated as a fair value hedge, including amounts measured as ineffective, and changes in the fair value of the hedged item, are recognized in the consolidated statements of income as a component of net capital gains and losses each period. The gain or loss on the termination of a fair value hedge is recognized in the consolidated statements of income as a component of net capital gains and losses during the period in which the termination occurs. When interest rate swaps are used in hedge accounting relationships, periodic settlements are recorded in net investment income.
	The gain or loss on the termination of an ineffective fair value hedge is reported in the consolidated statements of income as a component of net capital gains or losses. Additionally, when a hedged item is disposed, the Company will terminate the related derivative instrument and recognize the gain or loss on termination in the Company’s consolidated statements of income as a component of net capital gains or losses.
	Index-based guarantees embedded in indexed annuities (“index-based interest guarantees”) and Standard & Poor’s (“S&P”) 500 Index call spread options (“S&P 500 Index options”) do not qualify for hedge accounting. 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 in interest credited.
	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. Changes in the fair value of S&P 500 Index options are recorded in net investment income.
	Cash settlement activity of derivative contracts is reported in the consolidated statements of cash flows as a component of proceeds from or acquisition of other invested assets.
	In the consolidated balance sheets, the Company offsets fair value amounts recognized for interest rate swaps. See “Note 11—Derivative Financial Instruments.”
Policy Loans	Policy Loans
	Policy loans are stated at their aggregate unpaid principal balances and are secured by policy cash values.

Common Stock of FHLB	Common Stock
	In 2013, Standard became a member of the Federal Home Loan Bank of Seattle (“FHLB of Seattle”) and purchased the required common stock for membership and activity. The FHLB of Seattle common stock is carried at par value and accounted for under the cost method. The Company periodically evaluates the FHLB of Seattle common stock for OTTI. The Company’s determination of whether this investment is impaired is based on its assessment of the ultimate recoverability of cost rather than by recognizing temporary declines in value. There were no impairments recorded on the common stock of FHLB of Seattle in 2014 or 2013. The Federal Home Loan Bank of Des Moines (“FHLB of Des Moines”) and the FHLB of Seattle have announced that they have entered into a definitive agreement to merge the two banks. The merger agreement has been unanimously approved by the boards of directors of both banks and by the Federal Housing Finance Agency (“FHFA”). The potential merger must be approved by the members of both banks through a voting process that is expected to take place in the first half of 2015. The Company does not expect the merger to have a material effect on its business, financial position, results of operations, or cash flows.

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 are 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 54% and 93% expected to be amortized by years 5 and 15, respectively. DAC for group annuity products is amortized over 10 years with approximately 76% 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 insurance business assumed from Minnesota Life Insurance Company (“Minnesota Life”) and a block of group disability and group life insurance 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 insurance products. However, the VOBA related to the TIAA transaction associated with an in-force block of group long term disability insurance 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, 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 increase or decrease 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 the Company’s 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 6.5 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)			2014		2013

	Home office properties			$	139.4	$	136.9
	Office furniture and equipment				48.6		47.9
	Capitalized software				173		169.4
	Leasehold improvements				14.9		13.9

		Property and equipment, gross			375.9		368.1
	Less: accumulated depreciation				296.6		283.4

			Property and equipment, net	$	79.3	$	84.7


	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 2014, 2013 and 2012 was $17.8 million, $19.9 million and $24.1 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 34.2%, 33.8% and 33.3% of the corporate headquarters in Portland, Oregon at December 31, 2014, 2013 and 2012, 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 insurance 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 $188.3 million and $186.1 million at December 31, 2014 and 2013, respectively, and premiums on deposit and experience rated liabilities totaling $187.0 million and $193.5 million at December 31, 2014 and 2013, 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 on the consolidated balance sheets. Experience rated refunds (“ERRs”) 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 interest paid on income tax liabilities as interest expense and income tax penalties incurred as an operating expense.
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.
Accounting Pronouncements	Accounting Pronouncements
	Accounting Standards Update (“ASU”) No. 2014-01, *Accounting for Investments in Qualified Affordable Housing Projects*
	In January 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-01, Accounting for Investments in Qualified Affordable Housing Projects. This ASU permits entities to account for qualified affordable housing projects under the proportional amortization method (“PAM”) of accounting. Under PAM, the cost of the investments is amortized in each period in proportion to the tax credits and benefits of tax losses received in that period to total benefits to be received over the life of the investments and allows the amortization of the investments and the tax benefits to be recognized in income taxes on the consolidated statements of income.
	ASU No. 2014-01 is effective for annual reporting periods and interim reporting periods within those annual reporting periods beginning after December 15, 2014. Early adoption is permitted. The Company is adopting this ASU effective January 1, 2015, which it expects will decrease the beginning balance of 2015 retained earnings between $15 million and $20 million. Based on the investments held at December 31, 2014, the Company estimates the adoption of the ASU will result in a decrease in net income by approximately $13 million for 2015. The adoption of this ASU will change the timing of the benefit realized in net income but will not change the cumulative total benefit to net income over the life of the investments.

	ASU No. 2014-09, *Revenue from Contracts with Customers*
	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers. The main objective of ASU No. 2014-09 is to provide a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. This ASU does not apply to insurance contracts, financial instruments, and various other topics within the FASB Accounting Standards Codification. The core principle of the revenue model is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services.
	ASU No. 2014-09 is effective for annual reporting periods and interim reporting periods within those annual reporting periods beginning after December 15, 2016. Early adoption is not permitted. The Company’s revenue is primarily from insurance contracts and financial instruments; therefore, the Company does not expect this ASU to have a material effect on its results of operations.

	ASU No. 2015-01, *Income Statement – Extraordinary and Unusual Items*
	In January 2015, the FASB issued ASU No. 2015-01, Income Statement – Extraordinary and Unusual Items. The main objective of ASU No. 2015-01 is to eliminate from GAAP the concept of extraordinary items however, the requirement to disclose unusual and infrequent items still exists. Under this guidance, an entity will no longer segregate extraordinary items from the results of ordinary operations; separately present an extraordinary item on its income statement, net of tax, after income from continuing operations; and disclose income taxes and earnings-per-share data applicable to an extraordinary item. The ASU affects the reporting and disclosure requirements for an event that is unusual in nature or that occurs infrequently.
	ASU No. 2015-01 is effective for annual reporting periods and interim reporting periods within those annual reporting periods beginning after December 15, 2015. Early adoption is permitted if guidance is applied as of the beginning of the annual reporting period of adoption. The Company does not expect this ASU to have a material effect on its results of operations or disclosures.

Summary_Of_Significant_Account2

Summary Of Significant Accounting Policies (Tables)	12 Months Ended
Summary Of Significant Accounting Policies (Tables)	Dec. 31, 2014
Summary Of Significant Accounting Policies [Abstract]
Property And Equipment And Accumulated Depreciation
				December 31,
	(In millions)			2014		2013

	Home office properties			$	139.4	$	136.9
	Office furniture and equipment				48.6		47.9
	Capitalized software				173		169.4
	Leasehold improvements				14.9		13.9

		Property and equipment, gross			375.9		368.1
	Less: accumulated depreciation				296.6		283.4

			Property and equipment, net	$	79.3	$	84.7

Net_Income_Per_Common_Share_Ta

Net Income Per Common Share (Tables)	12 Months Ended
Net Income Per Common Share (Tables)	Dec. 31, 2014
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)		2014			2013	2012

	Net income		$	219.3	$	228.5	$	138.5

	Basic weighted-average common shares outstanding			43,018,215		44,243,364		44,283,771
	Stock options			342,791		194,978		74,232
	Stock awards			94,130		89,063		1,888

	Diluted weighted-average common shares outstanding			43,455,136		44,527,405		44,359,891

	Net income per common share:
		Basic	$	5.1	$	5.16	$	3.13
		Diluted		5.05		5.13		3.12

	Antidilutive shares not included in net income per diluted common
		share calculation		50,236		292,750		2,220,045

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	12 Months Ended
Share-Based Compensation (Tables)	Dec. 31, 2014
Share-Based Compensation [Abstract]
Schedule Of Compensation Cost And Related Income Tax Benefit Under Share-Based Compensation Plans		Years ended
		December 31,
	(In millions)		2014			2013			2012

	Compensation cost	$		8.1		$	8.3		$	6.7
	Related income tax benefit			2.8			2.9			2.3

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, 2012			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


		Granted		151,060			64.18
		Exercised		-261,208			41.64
		Forfeited		-4,218			48.55
		Expired		---			---

	Outstanding, December 31, 2014			1,540,728		$	45.31			5.4		$	37,827,108


	Options outstanding and exercisable:
		Vested or expected to be vested, December 31, 2014		1,524,736		$	45.25			5.4		$	37,523,747
		Fully vested and exercisable, December 31, 2014		1,220,891			43.85			4.6			31,759,884


	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,
		2014			2013			2012

	Dividend yield		1.78	%		2.25	%		2.36	%
	Expected stock price volatility		43.15			45.86			47.3
	Risk-free interest rate		1.81			1.31			1.02
	Expected option lives		6.0 years			6.2 years			5.9 years

Summary Of Activity Of Performance Shares Outstanding			Restricted Stock Units						Performance Shares
			Activity			Weighted-Average Grant DateFair Value			Activity		Weighted-Average Grant DateFair Value

	Unvested balance, January 1, 2012			---		$	---		190,968		$	44.05
		Granted		---					179,818
		Vested		---					-9,200
		Forfeited		---					-64,790

	Unvested balance, December 31, 2012			---			---		296,796			43.14


		Granted		59,823					129,172
		Vested		---					-13,964
		Forfeited		-3,057					-114,722

	Unvested balance, December 31, 2013			56,766			38.56		297,282			40.34


		Granted		48,294					77,634
		Vested		---					-54,076
		Forfeited		-685					-118,968

	Unvested balance, December 31, 2014			104,375			63.54		201,872			48.41

Assumptions Used To Determine The Fair Value Of ESPP Embedded Option		Years ended
		December 31,
		2014			2013			2012

	Dividend yield		1.80-1.84	%		1.69-2.44	%		2.38-3.06	%
	Expected stock price volatility		21.78-22.40			17.43-17.58			27.80-49.09
	Risk-free interest rate		0.03-0.06			0.07-0.11			0.06-0.13
	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,
	(Dollars in millions—except per share data)	2014			2013			2012

	Weighted-average grant date fair value per share for ESPP offerings	$	6.52		$	4.16		$	9.02
	Compensation cost		0.3			0.3			1.4
	Related income tax benefit		0.1			0.1			0.5

Retirement_Benefits_Tables

Retirement Benefits (Tables)	12 Months Ended
Retirement Benefits (Tables)	Dec. 31, 2014
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)							2014			2013			2012

	Change in projected benefit obligation:
			Projected benefit obligation at beginning of the year					$	-408.4		$	-418.5		$	-371.6
			Service cost						-8.4			-10.2			-9.7
			Interest cost						-19.3			-16.7			-16.5
			Actuarial (loss) gain						-87.1			26			-29.7
			Benefits paid						12.2			11			9

				Projected benefit obligation at end of the year					-511			-408.4			-418.5

	Change in fair value of plan assets:
			Fair value of plan assets at beginning of the year						440.4			386			349.7
			Actual return on plan assets						28.8			65.4			35.4
			Employer contributions						15			---			10
			Benefits paid and estimated expenses						-12.3			-11			-9.1

				Fair value of plan assets at end of the year					471.9			440.4			386

						Funded status at end of the year		$	-39.1		$	32		$	-32.5

Projected And Accumulated Benefit Obligations And Fair Value Of Plan Assets For Pension Plans		December 31,
	(In millions)	2014			2013			2012

	Projected benefit obligation	$	511		$	408.4		$	418.5
	Accumulated benefit obligation		471.9			374.2			386.5
	Fair value of plan assets		471.9			440.4			386

Amounts Recognized In Accumulated Other Comprehensive Loss			Years ended
			December 31,
	(In millions)		2014			2013			2012

	Net loss		$	90.6		$	31.4		$	78.3
	Prior service cost			1.9			2.3			2.7
		Total recognized in accumulated other comprehensive (income) loss	$	92.5		$	33.7		$	81

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)							2014			2013			2012

	Components of net periodic benefit (credit) cost:
			Service cost					$	8.5		$	10.3		$	9.8
			Interest cost						19.3			16.7			16.5
			Expected return on plan assets						-33.4			-29.3			-26.5
			Amortization of prior service cost						0.6			0.6			0.6
			Amortization of net actuarial loss						0.7			9.9			8.3
					Net periodic benefit (credit) cost				-4.3			8.2			8.7

	Other changes in plan assets and benefit obligation recognized
		in other comprehensive loss (income):
			Net loss (gain)						91.8			-62.2			20.9
			Amortization of prior service cost						-0.7			-0.6			-0.6
			Amortization of net actuarial loss						-0.7			-9.9			-8.3

					Total recognized in other comprehensive loss (income)				90.4			-72.7			12

						Total recognized in net periodic benefit (credit) cost and other
							comprehensive loss (income)	$	86.1		$	-64.5		$	20.7


	Weighted-average assumptions:
		Assumptions used for net periodic benefit (credit) cost:
			Discount rate						4.75	%		4	%		4.5	%
			Expected return on plan assets						7.71			7.7			7.69
			Rate of compensation increase						3.5			3			3.25

		Assumptions used to determine benefit obligations:
			Discount rate						4	%		4.75	%		4	%
			Rate of compensation increase						3			3.5			3

Expected Benefit Payments For Pension Plans	(In millions)		Amount

	2015		$	13.5
	2016			14.6
	2017			15.8
	2018			16.8
	2019			18
	2020-2024			111.1

Target And Actual Weighted-Average Asset Allocations For Pension Plans			December 31,
			2014			2014			2013
			Target			Actual			Actual

	Asset Category:
		Equity securities		50	%		50.3	%		49	%
		Debt securities		50			49.7			51

		Total		100	%		100	%		100	%

Estimated Fair Values Of Assets And Liabilities Measured And Recorded At Fair Value On A Recurring Basis								31-Dec-14
	(In millions)							Total			Level 1			Level 2			Level 3

	Assets:
		Equity securities:
			Pooled separate account funds:
				Large cap growth				$	47.3		$	47.3		$	---		$	---
				Large cap blend					74			74			---			---
				Large cap value					24.2			24.2			---			---
				Mid cap blend					71.5			71.5			---			---
				Foreign					20.3			20.3			---			---

					Total pooled separate account funds				237.3			237.3			---			---

		Debt securities:
				Stable asset fund					234.6			---			234.6			---

					Total			$	471.9		$	237.3		$	234.6		$	---


								31-Dec-13
	(In millions)							Total			Level 1			Level 2			Level 3

	Assets:
		Equity securities:
			Pooled separate account funds:
				Large cap growth				$	43		$	43		$	---		$	---
				Large cap blend					64.7			64.7			---			---
				Large cap value					21.7			21.7			---			---
				Mid cap blend					64.8			64.8			---			---
				Foreign					21.7			21.7			---			---

					Total pooled separate account funds				215.9			215.9			---			---

		Debt securities:
				Stable asset fund					224.5			---			224.5			---

					Total			$	440.4		$	215.9		$	224.5		$	---

Reconciliation Of Changes In Postretirement Benefit Plans' Accumulated Benefit Obligations, Fair Value Of Plan Assets And Funded Status								Years ended
								December 31,
	(In millions)							2014			2013			2012

	Change in accumulated postretirement benefit obligation:
			Accumulated postretirement benefit obligation at beginning of the year					$	-17.6		$	-23.9		$	-41
			Service cost						---			---			-1
			Interest cost						-0.8			-1.1			-1.8
			Plan amendments						---			0.8			25.2
			Actuarial (loss) gain						-7.3			5.2			-5.9
			Benefits paid						1			1.4			0.6

				Accumulated postretirement benefit obligation at end of the year					-24.7			-17.6			-23.9

	Change in fair value of postretirement plan assets:
			Fair value of plan assets at beginning of the year						19.3			21.6			20.7
			Actual return on plan assets						2			-1.6			1.2
			Employer contributions						0.9			0.7			0.3
			Benefits paid and estimated expenses						-1			-1.4			-0.6

				Fair value of plan assets at end of the year					21.2			19.3			21.6

						Funded status at end of the year		$	-3.5		$	1.7		$	-2.3

Amounts Recognized In Accumulated Other Comprehensive (Income) Loss			Years ended
			December 31,
	(In millions)		2014			2013			2012

	Net loss (gain)		$	2.9		$	-1		$	5.1
	Prior service credit			---			---			-17.1

		Total recognized in accumulated other comprehensive loss (income)	$	2.9		$	-1		$	-12

Assumed Health Care Cost Trend Rates For Next Year		Years ended
		December 31,
		2014			2013

	Medical		6.9	%		7.1	%
	Prescriptions		7.2			7.5
	HMO (Blended)		5.7			6
	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						2.8			-2.3

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)							2014			2013			2012

	Components of net periodic benefit (credit) cost:
			Service cost					$	---		$	---		$	1
			Interest cost						0.8			1			1.8
			Expected return on plan assets						-0.8			-0.8			-0.8
			Amortization of prior service cost						---			-26.3			-0.4
			Amortization of net actuarial loss						---			5.7			---
					Net periodic benefit (credit) cost				---			-20.4			1.6

	Other changes in plan assets and benefit obligation recognized
		in other comprehensive (income) loss:
			Net (gain) loss						-5.9			-3.3			5.5
			Prior service credit						---			---			-25.2
			Amortization of prior service credit						---			26.3			0.4
			Amortization of net actuarial loss						---			-5.8			---

					Total recognized in other comprehensive (income) loss				-5.9			17.2			-19.3

						Total recognized in net periodic benefit (credit) cost and other
							comprehensive (income) loss	$	-5.9		$	-3.2		$	-17.7


	Weighted-average assumptions:
		Assumptions used for net periodic benefit (credit) cost:
			Discount rate						4.8	%		4	%		4.5	%
			Expected return on plan assets						4.2			4.2			4.2

		Assumptions used to determine benefit obligations:
			Discount rate						4.1	%		4.8	%		4	%

Expected Benefit Payments For Postretirement Benefit Plan	(In millions)		Amount

	2015		$	1.5
	2016			1.5
	2017			1.4
	2018			1.4
	2019			1.3
	2020-2024			6.4

Target And Actual Weighted-Average Asset Allocations For Postretirement Medical Plan				Years ended
				December 31,
				2014			2014			2013
				Target			Actual			Actual

	Asset category:
		Debt securities			95	%		96.7	%		96.2	%
		Cash and cash equivalents			5			3.3			3.8

			Total		100	%		100	%		100	%

Estimated Fair Values Of Assets And Liabilities Measured And Recorded At Fair Value On A Recurring Basis								31-Dec-14
	(In millions)							Total			Level 1			Level 2			Level 3

	Assets:
		Debt securities:
			Municipal bonds					$	17.9		$	---		$	17.9		$	---
			Corporate bonds						2.6			---			2.6			---
		Cash and cash equivalents							0.7			0.7			---			---

				Total				$	21.2		$	0.7		$	20.5		$	---


								31-Dec-13
	(In millions)								Total			Level 1		Level 2			Level 3

	Assets:
		Debt securities:
			Municipal bonds					$	16.8		$	---		$	16.8		$	---
			Corporate bond						1.8			---			1.8			---
		Cash and cash equivalents							0.7			0.7			---			---

				Total				$	19.3		$	0.7		$	18.6		$	---

Segments_Tables

Segments (Tables)	12 Months Ended
Segments (Tables)	Dec. 31, 2014
Segments [Abstract]
Intersegment Administrative Fee Revenues		Years ended
		December 31,
	(In millions)	2014			2013			2012

	Intersegment administrative fees	$	19.3		$	18.6		$	17.9

Premiums, Administrative Fee And Net Investment Income By Major Product Line Or Category							Years ended
							December 31,
	(In millions)						2014			2013			2012

	Premiums:
		Insurance Services:
			Group life and AD&D				$	808.6		$	849.7		$	883.7
			Group long term disability					753.8			783			801.4
			Group short term disability					219			229			212.6
			Group other					79			78.3			78.9
			Experience rated refunds					-17.6			-13.1			4
				Total Employee Benefits				1,842.80			1,926.90			1,980.60
				Individual Disability				199.1			190.5			176.6
					Total Insurance Services premiums			2,041.90			2,117.40			2,157.20
		Asset Management:
				Retirement plans				1.7			2.2			1.9
				Individual annuities				8.8			4.7			4.8
					Total Asset Management premiums			10.5			6.9			6.7
						Total premiums	$	2,052.40		$	2,124.30		$	2,163.90

	Administrative fees:
		Insurance Services:
				Employee Benefits			$	16.5		$	15.1		$	13.7
				Individual Disability				0.2			0.2			0.2
					Total Insurance Services administrative fees			16.7			15.3			13.9
		Asset Management:
				Retirement plans				99.7			93.3			88
				Other financial services businesses				33.7			31.6			30.8
					Total Asset Management administrative fees			133.4			124.9			118.8
		Other administrative fees						-19.3			-18.6			-18
						Total administrative fees	$	130.8		$	121.6		$	114.7

	Net investment income:
		Insurance Services:
				Employee Benefits			$	247.4		$	267.8		$	286
				Individual Disability				52.1			52.8			53.7
					Total Insurance Services net investment income			299.5			320.6			339.7
		Asset Management:
				Retirement plans				113.2			103.2			94.9
				Individual annuities				155.9			177.2			170.6
				Other financial services businesses				14.2			12.8			13.1
					Total Asset Management net investment income			283.3			293.2			278.6
		Other net investment income						18.1			16.1			10.2
						Total net investment income	$	600.9		$	629.9		$	628.5

Segment Information					Year ended
					31-Dec-14
											Total
					Employee			Individual			Insurance			Asset
	(In millions)				Benefits			Disability			Services			Management			Other			Total

	Revenues:
		Premiums			$	1,842.80		$	199.1		$	2,041.90		$	10.5		$	---		$	2,052.40
		Administrative fees				16.5			0.2			16.7			133.4			-19.3			130.8
		Net investment income				247.4			52.1			299.5			283.3			18.1			600.9
		Net capital losses				---			---			---			---			-14			-14
				Total revenues		2,106.70			251.4			2,358.10			427.2			-15.2			2,770.10

	Benefits and expenses:
		Benefits to policyholders				1,431.40			130			1,561.40			20.8			---			1,582.20
		Interest credited				2.6			---			2.6			162			---			164.6
		Operating expenses				321.4			27.8			349.2			122.7			-1.3			470.6
		Commissions and bonuses				122.6			48			170.6			36.6			---			207.2
		Premium taxes				27.9			3.6			31.5			---			---			31.5
		Interest expense				---			---			---			---			31.8			31.8
		Net (increase) decrease in DAC,
			VOBA and other intangible assets			-1			-10.9			-11.9			7.2			---			-4.7
				Total benefits and expenses		1,904.90			198.5			2,103.40			349.3			30.5			2,483.20
	Income (loss) before income taxes				$	201.8		$	52.9		$	254.7		$	77.9		$	-45.7		$	286.9
	Total assets				$	5,952.50		$	2,399.50		$	8,352.00		$	14,025.60		$	352.3		$	22,729.90


					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		$	---		$	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				---			---			---			---			-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			---			1,655.40
		Interest credited				4.3			---			4.3			172.1			---			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			---			207.9
		Premium taxes				31.3			3.9			35.2			0.1			---			35.3
		Interest expense				---			---			---			---			34.4			34.4
		Net decrease (increase) in DAC,
			VOBA and other intangible assets			1.9			-12.4			-10.5			5.6			---			-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		$	---		$	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				---			---			---			---			-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			---			1,793.00
	Interest credited				4.2			---			4.2			167.1			---			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			---			203.7
	Premium taxes				33.6			3.9			37.5			---			---			37.5
	Interest expense				---			---			---			---			39.9			39.9
	Net decrease (increase) in DAC,
		VOBA and other intangible assets			6.9			-12.7			-5.8			4.9			---			-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

Parent_Holding_Company_Condens1

Parent Holding Company Condensed Financial Information (Tables)	12 Months Ended
	Dec. 31, 2014
Parent Holding Company Condensed Financial Information [Abstract]
Condensed Statements Of Income					Years ended
					December 31,
	(In millions)					2014			2013			2012
	Revenues:
		Net investment income				$	12.9		$	13.2		$	5
		Net capital (losses) gains					-0.8			0.2			0.1

				Total revenues			12.1			13.4			5.1

	Expenses:
		Interest expense					31.7			34.2			39.7
		Operating expenses					0.5			0.9			4.5

				Total expenses			32.2			35.1			44.2


	Loss before income taxes and equity in net income of subsidiaries						-20.1			-21.7			-39.1
	Income tax benefit						-6.1			-7.7			-14.2
	Equity in net income of subsidiaries						233.3			242.5			163.4

	Net income						219.3			228.5			138.5

	Other comprehensive (loss) income, net of tax:
		Other comprehensive (loss) income from parent					-57.5			47			1.7
		Other comprehensive income (loss) from subsidiaries					37.1			-221.6			72.5
			Total other comprehensive (loss) income, net of tax				-20.4			-174.6			74.2

	Comprehensive income					$	198.9		$	53.9		$	212.7

Condensed Balance Sheets					December 31,
	(In millions)				2014			2013
	A S S E T S

	Cash and cash equivalents				$	70.5		$	125.2
	Investment in subsidiaries					2,317.90			2,252.90
	Receivable from subsidiaries					0.9			1.5
	Subordinated surplus note ("Surplus Note") receivable from subsidiary					250			250
	Other assets					77.9			80.3

				Total assets	$	2,717.20		$	2,709.90

	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			$	502.9		$	550
		Other liabilities				42.5			7.1

			Total liabilities			545.4			557.1


	Shareholders’ equity:
			Total shareholders' equity			2,171.80			2,152.80

				Total liabilities and shareholders’ equity	$	2,717.20		$	2,709.90

Condensed Statements Of Cash Flows					Years ended
					December 31,
	(In millions)				2014				2013		2012

	Operating:
		Net income			$	219.3		$	228.5		$	138.5
		Adjustments to reconcile net income to net cash provided by operating activities:
			Equity in net income of subsidiaries			-233.3			-242.5			-163.4
			Dividends received from consolidated subsidiaries			423			147			328.7
			Changes in operating assets and liabilities			-13.4			23.7			-2.5

				Net cash provided by operating activities		395.6			156.7			301.3

	Investing:
		Capital contributions to subsidiaries				-240.3			-0.7			-14.5
		Return of capital from subsidiaries				27			7.8			7.3
		Surplus note receivable from subsidiary				---			---			-250
		Receivables from subsidiaries, net				0.3			-0.3			3.4
		Investment securities and other				-2.8			0.2			1.4

				Net cash (used in) provided by investing activities		-215.8			7			-252.4

	Financing:
		Issuance and repurchase of common stock, net				-132.7			-29.7			0.9
		Repayment of debt				-47.1			---			-250
		Issuance of debt, net of issuance costs				---			---			246.7
		Dividends paid on common stock				-54.7			-48.5			-41.3

				Net cash used in financing activities		-234.5			-78.2			-43.7

	(Decrease) increase in cash and cash equivalents					-54.7			85.5			5.2
	Cash and cash equivalents, beginning of year					125.2			39.7			34.5

	Cash and cash equivalents, end of year				$	70.5		$	125.2		$	39.7

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2014
Income Taxes Disclosure [Abstract]
Provision For Income Taxes			Years ended
			December 31,
	(In millions)		2014			2013			2012

	Current		$	56.9		$	71.1		$	38.5
	Deferred			10.7			13.4			6.4

		Total income tax provision	$	67.6		$	84.5		$	44.9

Reconciliation Between Taxes Calculated Federal Corporate Tax On Income Before Income Taxes And Recorded Income Tax Provision				Years ended
				December 31,
	(In millions)			2014			2013			2012

	Tax at federal corporate rate of 35%			$	100.4		$	109.6		$	64.2
	(Decrease) increase in rate resulting from:
		Tax exempt interest			---			---			-0.1
		Dividends received deduction			-4.4			-3.6			-3.6
		State income taxes, net of federal benefit			2.2			1.3			0.2
		Federal tax credits			-33.7			-24.9			-17.4
		Other			3.1			2.1			1.6

			Total income tax provision	$	67.6		$	84.5		$	44.9

Net Deferred Tax Asset (Liability)
					December 31,
	(In millions)				2014			2013			2012

	Policyholder liabilities				$	9.6		$	1.2		$	1.8
	Compensation and benefit plans					49.9			12.6			44
	Loss carryforwards					46.6			49.7			51.7
	Investments					30.4			45.6			35.8
	Other					1.3			3.5			2.2

		Total deferred tax assets				137.8			112.6			135.5
	Less: valuation allowances					-9.5			-9.5			-3.1

			Net deferred tax assets			128.3			103.1			132.4

	Net unrealized capital gains					116.8			95.7			210
	Capitalized software					5.6			6.8			8.3
	Deferred policy acquisition costs					67			63.5			59.7
	Intangible assets					---			0.9			2
	Other					2			0.9			0.5

		Total deferred tax liabilities				191.4			167.8			280.5

			Net deferred tax liability		$	-63.1		$	-64.7		$	-148.1

Fair_Value_Tables

Fair Value (Tables)	12 Months Ended
Fair Value (Tables)	Dec. 31, 2014
Fair Value [Abstract]
Estimated Fair Value and the Carrying Value of Each Financial Instrument Categorized by Fair Value Hierarcy							31-Dec-14
							Carrying			Fair
	(In millions)						Value			Value			Level 1			Level 2			Level 3

	Assets:
		Fixed maturity securities:
			Corporate bonds				$	7,272.60		$	7,272.60		$	---		$	7,183.60		$	89
			U.S. government and agency bonds					300.1			300.1			---			300.1			---
			U.S. state and political subdivision bonds					136.1			136.1			---			136.1			---
			Foreign government bonds					64.9			64.9			---			64.9			---
				Total fixed maturity securities			$	7,773.70		$	7,773.70		$	---		$	7,684.70		$	89

		Commercial mortgage loans, net					$	5,321.10		$	6,021.50		$	---		$	---		$	6,021.50
		S&P 500 Index options						13.6			13.6			---			---			13.6
		Policy loans						2.2			2.2			---			---			2.2
		Separate account assets						7,179.80			7,179.80			7,066.40			113.4			---

	Liabilities:
		Other policyholder funds,
			investment-type contracts				$	5,961.10		$	6,232.50		$	---		$	---		$	6,232.50
		Index-based interest guarantees						77			77			---			---			77
		Interest rate swaps						4.7			4.7			---			4.7			---
		Short-term debt						1.1			1.5			---			1.5			---
		Long-term debt						503.9			538.4			---			538.4			---


							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		$	---		$	6,429.70		$	116
			U.S. government and agency bonds					353.2			353.2			---			353.2			---
			U.S. state and political subdivision bonds					140.3			140.3			---			140.3			---
			Foreign government bonds					65.5			65.5			---			65.5			---
			S&P 500 Index options					15.8			15.8			---			---			15.8
				Total fixed maturity securities			$	7,120.50		$	7,120.50		$	---		$	6,988.70		$	131.8

		Commercial mortgage loans, net					$	5,405.10		$	5,769.60		$	---		$	---		$	5,769.60
		Policy loans						2.5			2.5			---			---			2.5
		Separate account assets						6,393.20			6,393.20			6,249.20			144			---

	Liabilities:
		Other policyholder funds,
			investment-type contracts				$	5,469.80		$	5,632.70		$	---		$	---		$	5,632.70
		Index-based interest guarantees						67.6			67.6			---			---			67.6
		Short-term debt						1.5			1.9			---			1.9			---
		Long-term debt						551.9			553.6			---			553.6			---

Valuation Techniques Fair Values Of Assets And Liabilities Measured And Recorded At Fair Value On A Recurring Basis								31-Dec-14					31-Dec-13
								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		$	13.6		(a)		$	15.8		(a)
	Index-based interest			Discounted cash		Expected future		$	77		1% - 3%		$	67.6		1% - 6%
		guarantees		flow		option purchase
						Various assumptions					(b)					(b)
				Black-Scholes option pricing model		Various assumptions					(a)					(a)
	Commercial mortgage loans			Appraisals		Reduction on appraisal		$	56		0% - 37%		$	68.7		0% - 13%
				Cash flows		Capitalization rate (c)					7% - 16%					7% - 16%
	Real Estate Owned			Appraisals		Reduction on appraisal		$	10.3		0% - 11%		$	35.2		0% - 53%


	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, 2014 and December 31, 2013.
	Capitalization rates are used as an internal analysis in converting the underlying property 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, 2014
				Assets															Liabilities
							U.S.			U.S. State									Index-
							Government			and Political			S&P 500						Based
				Corporate			and Agency			Subdivision			Index			Total			Interest
	(In millions)			Bonds			Bonds			Bonds			Options			Assets			Guarantees

	Beginning balance			$	116		$	---		$	---		$	15.8		$	131.8		$	67.6
	Total realized/unrealized gains (losses):
		Included in net income			---			---			---			8.6			8.6			7.2
		Included in other comprehensive income (loss)			-3.8			---			---			---			-3.8			---
	Purchases, issuances, sales and settlements:
		Purchases			---			---			---			9.3			9.3			---
		Issuances			---			---			---			---			---			12.2
		Sales			---			---			---			---			---			---
		Settlements			---			---			---			-20.1			-20.1			-10
	Transfers into Level 3				8.4			---			---			---			8.4			---
	Transfers out of Level 3				-31.6			---			---			---			-31.6			---

	Ending balance			$	89		$	---		$	---		$	13.6		$	102.6		$	77


				Year ended December 31, 2013
				Assets																Liabilities
							U.S.			U.S. State										Index-
							Government			and Political				S&P 500						Based
				Corporate			and Agency			Subdivision				Index			Total			Interest
	(In millions)			Bonds			Bonds			Bonds				Options			Assets			Guarantees

	Beginning balance			$	80.4		$	1.1		$	1.7			$	11.3		$	94.5		$	57.4
	Total realized/unrealized gains (losses):
		Included in net income			---			---			---				14.4			14.4			9
		Included in other comprehensive income (loss)			6.2			---			---				---			6.2			---
	Purchases, issuances, sales and settlements:
		Purchases			---			---			---				9.4			9.4			---
		Issuances			---			---			---				---			---			6
		Sales			---			---			---				---			---			---
		Settlements			---			---			---				-19.3			-19.3			-4.8
	Transfers into Level 3				61.6			---			---				---			61.6			---
	Transfers out of Level 3				-32.2			-1.1			-1.7				---			-35			---

	Ending balance			$	116		$	---		$	---			$	15.8		$	131.8		$	67.6

Changes In Unrealized Gains (Losses) Included In Net Income Relating To Positions Still Held			Years ended
			December 31,
	(In millions)		2014			2013

	Assets:
		S&P 500 Index options	$	4.3		$	6.4

	Liabilities:
		Index-based interest guarantees	$	14		$	-12.9

Assets Measured At Fair Value On A Nonrecurring Basis And Still Held As Of The Balance Sheet Date			31-Dec-14
	(In millions)		Total			Level 1			Level 2			Level 3

	Commercial mortgage loans		$	56		$	---		$	---		$	56
	Real Estate Owned			10.3			---			---			10.3

		Total assets measured at fair value on a nonrecurring basis	$	66.3		$	---		$	---		$	66.3


			31-Dec-13
	(In millions)		Total			Level 1			Level 2			Level 3

	Commercial mortgage loans		$	68.7		$	---		$	---		$	68.7
	Real Estate Owned			35.2			---			---			35.2

		Total assets measured at fair value on a nonrecurring basis	$	103.9		$	---		$	---		$	103.9

Investments_Tables

Investments (Tables)	12 Months Ended
Investments (Tables)	Dec. 31, 2014
Investments [Abstract]
Amortized Costs And Fair Values Of Fixed Maturity Securities Available-For-Sale			December 31,
			2014
			Amortized			Unrealized			Unrealized			Fair
	(In millions)		Cost			Gains			Losses			Value

	Corporate bonds		$	6,943.80		$	367.9		$	-39.1		$	7,272.60
	U.S. government and agency bonds			262			38.3			-0.2			300.1
	U.S. state and political subdivision bonds			125.8			10.4			-0.1			136.1
	Foreign government bonds			58.4			6.5			---			64.9

		Total fixed maturity securities	$	7,390.00		$	423.1		$	-39.4		$	7,773.70


			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			---			65.5
	S&P 500 Index options			15.8			---			---			15.8

		Total fixed maturity securities	$	6,811.90		$	385.8		$	-77.2		$	7,120.50

Schedule Of Contractual Maturities Of Fixed Maturity Securities Available-For-Sale			31-Dec-14						31-Dec-13
			Amortized			Fair			Amortized			Fair
	(In millions)		Cost			Value			Cost			Value


	Due in one year or less		$	649		$	658		$	486.2		$	495.1
	Due after one year through five years			3,060.80			3,215.40			2,974.50			3,168.90
	Due after five years through ten years			2,847.90			2,916.70			2,497.50			2,524.60
	Due after ten years			832.3			983.6			853.7			931.9

		Total fixed maturity securities	$	7,390.00		$	7,773.70		$	6,811.90		$	7,120.50

Schedule Of Gross Unrealized Losses And Fair Value Of Investments					31-Dec-14
					Total						Less than 12 months						12 or more months
	(Dollars in millions)				Number			Amount			Number			Amount			Number			Amount

	Unrealized losses:
			Corporate bonds			995		$	39.1			683		$	21.3			312		$	17.8
			U.S. government and agency bonds			5			0.2			---			---			5			0.2
			U.S. state and political subdivision bonds			4			0.1			---			---			4			0.1

				Total		1,004		$	39.4			683		$	21.3			321		$	18.1

	Fair market value of securities with
		unrealized losses:
			Corporate bonds			995		$	1,763.20			683		$	1,162.20			312		$	601
			U.S. government and agency bonds			5			6.4			---			---			5			6.4
			U.S. state and political subdivision bonds			4			6.9			---			---			4			6.9

				Total		1,004		$	1,776.50			683		$	1,162.20			321		$	614.3


					31-Dec-13
					Total						Less than 12 months						12 or more months
	(Dollars in millions)				Number			Amount			Number			Amount			Number			Amount

	Unrealized losses:
			Corporate bonds			908		$	76			848		$	66.3			60		$	9.7
			U.S. government and agency bonds			9			0.4			9			0.4			---			---
			U.S. state and political subdivision bonds			10			0.8			10			0.8			---			---

				Total		927		$	77.2			867		$	67.5			60		$	9.7

	Fair market value of securities with
		unrealized losses:
			Corporate bonds			908		$	1,663.80			848		$	1,557.70			60		$	106.1
			U.S. government and agency bonds			9			16.9			9			16.9			---			---
			U.S. state and political subdivision bonds			10			15.4			10			15.4			---			---

				Total		927		$	1,696.10			867		$	1,590.00			60		$	106.1

Commercial Mortgage Loan Portfolio By Property Type, By Geographic Region Within The U.S. And By U.S. State				31-Dec-14						31-Dec-13
	(Dollars in millions)			Amount			Percent			Amount			Percent


	Property type:
		Retail		$	2,627.10		49.4	%		$	2,629.20		48.6	%
		Office			1,013.40		19.1				982.4		18.2
		Industrial			1,001.50		18.8				1,008.70		18.7
		Commercial			213.6		4				218.6		4
		Hotel/motel			165.7		3.1				276.3		5.1
		Apartment and other			299.8		5.6				289.9		5.4

			Total commercial mortgage loans, net	$	5,321.10		100	%		$	5,405.10		100	%

	Geographic region*:
		Pacific		$	1,914.60		36	%		$	1,910.10		35.3	%
		South Atlantic			1,065.50		20				1,090.00		20.2
		West South Central			676.9		12.7				672.8		12.4
		Mountain			606.5		11.4				611.4		11.3
		East North Central			466		8.8				473.8		8.8
		Middle Atlantic			215.3		4				223		4.1
		East South Central			188.7		3.6				166.6		3.1
		West North Central			140.1		2.6				186.9		3.5
		New England			47.5		0.9				70.5		1.3

			Total commercial mortgage loans, net	$	5,321.10		100	%		$	5,405.10		100	%

	U.S. state:
		California		$	1,434.20		27	%		$	1,455.50		26.9	%
		Texas			623.4		11.7				618.8		11.5
		Florida			309.4		5.8				331.6		6.1
		Georgia			306.6		5.8				310.7		5.8
		Other states			2,647.50		49.7				2,688.50		49.7

			Total commercial mortgage loans, net	$	5,321.10		100	%		$	5,405.10		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)			2014			2013

	Commercial mortgage loan loss allowance:
	Beginning balance			$	43.6		$	46.6
		Provision			7.1			15.9
		Charge-offs, net			-10.7			-18.9

			Ending balance	$	40		$	43.6

	Specific loan loss allowance			$	23.8		$	25.9
	General loan loss allowance				16.2			17.7

			Total commercial mortgage loan loss allowance	$	40		$	43.6

Schedule Of Recorded Investment In Commercial Mortgage Loans				December 31,
	(In millions)			2014			2013

	Commercial mortgage loans collectively evaluated for impairment			$	5,255.20		$	5,334.40
	Commercial mortgage loans individually evaluated for impairment				105.9			114.3
	Commercial mortgage loan loss allowance				-40			-43.6

			Total commercial mortgage loans, net	$	5,321.10		$	5,405.10

Performing And Nonperforming Commercial Mortgage Loans By Property Type				31-Dec-14
													Hotel/						Apartment
	(In millions)			Retail			Industrial			Office			Motel			Commercial			and Other			Total

	Performing commercial mortgage
		loans		$	2,622.40		$	1,001.40		$	1,012.70		$	165.7		$	213.6		$	299.1		$	5,314.90
	Nonperforming commercial
		mortgage loans			4.7			0.1			0.7			---			---			0.7			6.2

			Total commercial mortgage loans	$	2,627.10		$	1,001.50		$	1,013.40		$	165.7		$	213.6		$	299.8		$	5,321.10


				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			---			---			---			11.9

			Total commercial mortgage loans	$	2,629.20		$	1,008.70		$	982.4		$	276.3		$	218.6		$	289.9		$	5,405.10

Impaired Commercial Mortgage Loans Identified In Management's Specific Review Of Probable Loan Losses And The Related Allowance							31-Dec-14
										Unpaid						Amount on
							Recorded			Principal			Related			Nonaccrual
	(In millions)						Investment			Balance			Allowance			Status

	Impaired commercial mortgage loans:
		Without specific loan loss allowances:
			Retail				$	25		$	25		$	---		$	10.5
			Office					1.6			1.6			---			---
			Commercial					2.3			2.3			---			0.5
			Apartment and other					2.8			2.8			---			---
				Total impaired commercial mortgage loans without specific
					loan loss allowances			31.7			31.7			---			11

		With specific loan loss allowances:
			Retail					52.2			52.2			12.3			7.7
			Office					8.6			8.6			2.9			---
			Industrial					4.6			4.6			1.6			0.1
			Commercial					8.5			8.5			7			0.6
			Apartment and other					0.3			0.3			---			---
				Total impaired commercial mortgage loans with specific
					loan loss allowances			74.2			74.2			23.8			8.4

						Total impaired commercial mortgage loans	$	105.9		$	105.9		$	23.8		$	19.4


							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		$	---		$	7.6
			Office					3.9			3.9			---			1.5
			Industrial					1			1			---			---
			Commercial					1.8			1.8			---			---
			Apartment and other					3.8			3.8			---			---
				Total impaired commercial mortgage loans without specific
					loan loss allowances			26.6			26.6			---			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			---			---
				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

Information Related To Troubled Debt Restructurings Of Financing Receivables							Year ended
							31-Dec-14
										Pre-			Post-
										Restructuring			Restructuring
							Number of			Recorded			Recorded
	(Dollars in millions)						Loans			Investment			Investment

	Troubled debt restructurings:
			Retail					45		$	42.7		$	40.9
			Office					3			1.4			1.2
			Industrial					4			3.1			3.4
			Commercial					2			3			3.2
				Total troubled debt restructurings				54		$	50.2		$	48.7


							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

Average Recorded Investment In Impaired Commercial Mortgage Loans Before Specific Allowances For Losses		Years ended December 31,
	(In millions)	2014			2013			2012

	Average recorded investment	$	105.6		$	113.4		$	101.3

Aging Of Commercial Mortgage Loans By Property Type				31-Dec-14
																						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		$	0.2		$	2		$	4.8		$	7		$	-2.1		$	2,622.20		$	2,627.10
		Office			1.9			---			0.8			2.7			---			1,010.70			1,013.40
		Industrial			0.5			---			0.3			0.8			-0.2			1,000.90			1,001.50
		Hotel/motel			---			---			---			---			---			165.7			165.7
		Commercial			---			---			---			---			---			213.6			213.6
		Apartment and other			0.2			0.7			---			0.9			---			298.9			299.8

			Total commercial mortgage loans	$	2.8		$	2.7		$	5.9		$	11.4		$	-2.3		$	5,312.00		$	5,321.10


				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			---			3.7			5			-0.9			978.3			982.4
		Industrial			---			3.3			1.8			5.1			-0.9			1,004.50			1,008.70
		Hotel/motel			6.3			---			---			6.3			---			270			276.3
		Commercial			---			---			---			---			---			218.6			218.6
		Apartment and other			---			---			---			---			---			289.9			289.9

			Total commercial mortgage loans	$	10.4		$	3.6		$	11.6		$	25.6		$	-3.3		$	5,382.80		$	5,405.10

Net Investment Income Summarized By Investment Type						Years ended
						December 31,
	(In millions)						2014			2013		2012

	Fixed maturity securities					$	296.4		$	303		$	316.8
	Commercial mortgage loans						332.1			341.7			331.9
	Real estate						1.1			-1.4			-1
	S&P 500 Index options						8.6			14.4			7.8
	Other						4.5			9			8.6

				Gross investment income			642.7			666.7			664.1
	Investment expenses						-22.4			-22.9			-22.3
	Tax-advantaged investment operating losses						-19.4			-13.9			-13.3

					Net investment income	$	600.9		$	629.9		$	628.5

Schedule Of Gross Capital Gains And Losses By Investment Type					Years ended
					December 31,
	(In millions)				2014			2013			2012

	Gains:
		Fixed maturity securities			$	5.9		$	9.8		$	10.8
		Commercial mortgage loans				2.4			2.4			1.5
		Real estate				2			3			1.3
		Other				---			0.2			0.6

			Gross capital gains			10.3			15.4			14.2

	Losses:
		Fixed maturity securities				-2.8			-2.3			-5
		Provision for commercial mortgage loan losses				-7.1			-15.9			-13.4
		Real estate				-6.4			-9.6			-3.5
		Other				-8			-3.3			-1

			Gross capital losses			-24.3			-31.1			-22.9

				Net capital losses	$	-14		$	-15.7		$	-8.7

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	12 Months Ended
Derivative Financial Instruments (Tables)	Dec. 31, 2014
Derivative Financial Instruments [Abstract]
Fair Value Of The Company's Derivative Assets And Liabilities				December 31,
				2014					2013
				Notional			Fair		Notional			Fair
	(In millions)			Amount			Value		Amount			Value
	Qualifying Fair Value Hedging Instruments
	Liabilities:
		Other liabilities:
			Interest rate swaps	$	350		$	4.7	$	---		$	---

	Non-Qualifying Hedging Instruments
	Assets:
		Other invested assets
			S&P 500 Index options		418.2			13.6		350.5			15.8

	Liabilities:
		Other policyholder funds:
			Index-based interest guarantees		---	-1		77		---	-1		67.6

Offsetting of Interest Rate Swaps				December 31,
	(In millions)			2014			2013
	Offsetting of Interest Rate Swaps

	Interest rate swaps, liabilities			$	-5.1		$	---
	Interest rate swaps, assets				0.4			---

		Net interest rate swaps			-4.7			---
		Accrued interest payable			-2.2			---
		Collateral pledged			12.2			---

			Net amount	$	5.3		$	---

Gain Or Loss Recognized In Earnings From The Change In Fair Value Of Derivative Assets And Liabilities				Years ended December 31,
	(In millions)			2014			2013		2012
	Qualifying Fair Value Hedging Instruments

	Net capital losses:
		Interest rate swaps		$	-4.7		$	---	$	---

	Non-Qualifying Hedging Instruments

	Net investment income:
		S&P 500 Index options			8.6			14.4		7.8

	Interest credited:
		Index-based interest guarantees			-7.2			-9		-6.4

			Net (losses) gains	$	-3.3		$	5.4	$	1.4

Fair Value Of Derivative Assets And Maximum Credit Risk Exposure				31-Dec-14
				Assets at			Maximum
	(In millions)			Fair Value			Credit Risk

	Counterparty:
		The Bank of New York Mellon		$	4.5		$	5.4
		Goldman Sachs			3.5			4.4
		Merrill Lynch International			5.6			9.3

			Total	$	13.6		$	19.1

Deferred_Acquisition_Costs_DAC1

Deferred Acquisition Costs ("DAC"), Value Of Business Acquired ("VOBA") And Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
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)			2014			2013			2012

	Carrying value at beginning 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 balance at beginning of year, net		371.3			346.5			344.9

	Deferred or acquired during year:
		DAC			80.1			76.9			71.4


			Total deferred or acquired during year		80.1			76.9			71.4

	Amortized during year:
		DAC			-62.3			-42.7			-60.9
		VOBA			-2.3			-3.3			-3
		Other intangible assets			-5.8			-6.1			-5.9

			Total amortized during year		-70.4			-52.1			-69.8

	Carrying value at end of year, net:
		DAC			336.9			319.1			284.9
		VOBA			17.8			20.1			23.4
		Other intangible assets			26.3			32.1			38.2

			Total carrying value at end of year, net	$	381		$	371.3		$	346.5

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-14						31-Dec-13
	(Dollars in millions)	Amount			Percent			Amount			Percent

	DAC	$	82.4		24.5	%		$	80.1		25.1	%
	VOBA		3.7		20.8				4.3		21.4

Impact Of Unlocking On DAC And VOBA Balances		Years ended
		December 31,
	(In millions)	2014			2013			2012


	Decrease to DAC and VOBA	$	-3.2		$	-1.7		$	-1.7

Schedule Of The Estimated Net Amortization Of Value Of Business Acquired And Other Intangible Assets For The Next Five Years	(In millions)	Amount

	2015	$	7.6
	2016		6.1
	2017		4.6
	2018		4.3
	2019		4.1

Liability_For_Unpaid_Claims_Cl1

Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds (Tables)	12 Months Ended
	Dec. 31, 2014
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)			2014		2013		2012

	Net balance at beginning of the year:
		Balance at beginning of the year, gross of reinsurance		$	4,021.90	$	4,005.90	$	3,857.00
		Less: reinsurance recoverable			-139.9		-128.6		-117.3

			Net balance at beginning of the year		3,882.00		3,877.30		3,739.70

	Incurred related to:
		Current year			1,033.10		1,081.70		1,140.30
		Prior year's interest			172.3		180.3		181.2
		Prior years			-117.4		-133.2		-79.8

			Total incurred		1,088.00		1,128.80		1,241.70

	Paid related to:
		Current year			-322.2		-345.9		-354.8
		Prior year			-780.9		-778.2		-749.3

			Total paid		-1,103.10		-1,124.10		-1,104.10

	Net balance at end of the year				3,866.90		3,882.00		3,877.30
		Plus: reinsurance recoverable			154.8		139.9		128.6

			Balance at end of the year, gross of reinsurance	$	4,021.70	$	4,021.90	$	4,005.90

Future Policy Benefits And Claims				Years ended
				December 31,
	(In millions)			2014		2013		2012

	Future policy benefits and claims			$	5,832.30	$	5,846.90	$	5,843.20
		Less: Group life reserves			-727.7		-751.7		-765.3
		Less: Individual life reserves			-596.3		-603.6		-600.9
		Less: Group and individual annuity reserves			-219.9		-220		-237.4
		Less: Individual disability active life reserves			-266.7		-249.7		-233.7

			Liability for unpaid claims and claim adjustment expenses	$	4,021.70	$	4,021.90	$	4,005.90

Composition Of Other Policyholder Funds				Years ended
				December 31,
	(In millions)			2014		2013

	Retirement plan stable asset funds			$	2,104.40	$	1,954.10
	Individual fixed-rate annuity funds				2,383.60		2,541.70
	Investment only stable asset funds				610.9		326.1
	Indexed annuity funds				504		440.8
	Other				934.9		788.9

		Total other policyholder funds		$	6,537.80	$	6,051.60

Reinsurance_Tables

Reinsurance (Tables)	12 Months Ended
Reinsurance (Tables)	Dec. 31, 2014
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

	2014:00:00
	Life insurance in-force			$	306,566.00	$	6,239.80	$	51.5	$	300,377.70	---	%
	Premiums:
		Life insurance and annuities		$	854.6	$	46.3	$	---	$	808.3	---
		Accident and health insurance			1,231.50		80.2		92.8		1,244.10	7.5

			Total premiums	$	2,086.10	$	126.5	$	92.8	$	2,052.40	4.5
	2013:00:00
	Life insurance in-force			$	321,881.70	$	5,966.80	$	57.7	$	315,972.60	---	%
	Premiums:
		Life insurance and annuities		$	898.5	$	48.5	$	---	$	850	---
		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	---	%
	Premiums:
		Life insurance and annuities		$	937.9	$	51	$	---	$	886.9	---
		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

Insurance_Information_Tables

Insurance Information (Tables)	12 Months Ended
Insurance Information (Tables)	Dec. 31, 2014
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⁾

	2014:00:00
	Employee Benefits			$	25.7	$	3,936.90	$	302.8	$	1,842.80	$	247.4	$	1,434.00	$	21.9	$	470.9
	Individual Disability				228.8		1,675.50		196.9		199.1		52.1		130		24		68.5

		Total Insurance
			Services		254.5		5,612.40		499.7		2,041.90		299.5		1,564.00		45.9		539.4
		Asset Management			82.4		219.9		6,038.10		10.5		283.3		182.8		21.4		166.5

			Total	$	336.9	$	5,832.30	$	6,537.80	$	2,052.40	$	582.8	$	1,746.80	$	67.3	$	705.9


	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


	(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
Regulatory Matters (Tables)	Dec. 31, 2014
Regulatory Matters [Abstract]
Reconciliation of capital and surplus of the insurance to GAAP equity			December 31,
	(In millions)		2014		2013

	Statutory capital and surplus		$	1,228.40	$	1,359.00

	Adjustments to reconcile to GAAP equity:
		Future policy benefits and other policyholder funds		276		325.8
		DAC, VOBA and other intangible assets		365.7		351.6
		Deferred tax liabilities		-245.6		-265.3
		Asset valuation reserve		106.2		127.5
		Valuation of investments		259.6		236.4
		Interest maintenance reserve		28.5		25.5
		Equity of StanCorp and its non-insurance subsidiaries		277.5		116.1
		Non-admitted assets		166.3		178.2
		Pension and postretirement benefit plans		-11.3		-6.6
		Capital lease obligations		-2.1		-3.4
		Surplus note		-250		-250
		Other, net		-27.4		-42

	GAAP equity		$	2,171.80	$	2,152.80

Reconciliation Of The Statutory Gain From Operations to GAAP Net Income			Years ended December 31,
	(In millions)		2014		2013		2012

	Statutory net income		$	213.4	$	198.5	$	131.5

	Adjustments to reconcile to GAAP net income:
		Future policy benefits and other policyholder funds		-24.3		11		26.4
		DAC and VOBA, net of amortization		9.2		9.4		5.5
		Deferred income taxes		-5.7		-13.5		-22.4
		Current income taxes		9.6		9.6		17.2
		Earnings of StanCorp and its non-insurance subsidiaries		8.9		-8.9		-23.8
		Deferred capital gains (interest maintenance reserve)		3		0.7		5
		Pension and postretirement benefit plans		-2.6		17.6		-1.7
		Share based compensation		---		-3.6		-5.4
		Investments		7.9		8.5		5.8
		Other, net		-0.1		-0.8		0.4

	GAAP net income		$	219.3	$	228.5	$	138.5

LongTerm_Debt_Tables

Long-Term Debt (Tables)	12 Months Ended
Long-Term Debt (Tables)	Dec. 31, 2014
Long-Term Debt [Abstract]
Long-Term Debt				December 31,
	(In millions)			2014		2013

	Long-term debt:
		Senior notes		$	250	$	250
		Subordinated debt			252.9		300
		Other long-term borrowings			1		1.9

			Total long-term debt	$	503.9	$	551.9

Commitments_And_Contingencies_

Commitments And Contingencies (Tables)	12 Months Ended
Commitments And Contingencies (Tables)	Dec. 31, 2014
Commitments And Contingencies [Abstract]
Future Minimum Payments Under The Leases	(In millions)

	2015	$	9.2
	2016		8.8
	2017		8.3
	2018		3.9
	2019		1.9
	Thereafter		1.3

Minimum Future Rental Receivables On Non-Cancelable Leases Of Retail And Office Space	(In millions)

	2015	$	7.3
	2016		5.3
	2017		2.6
	2018		2
	2019		1.4
	Thereafter		4.9

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
Accumulated Other Comprehensive Income (Tables)	Dec. 31, 2014
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, 2013			$	383	$	-73.7	$	309.3

		Other comprehensive (loss) income, net of tax
			before reclassification adjustment⁽¹⁾		-205.3		41.2		-164.1
		Amounts reclassified from accumulated
			other comprehensive income, net of tax⁽²⁾		-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

		Other comprehensive income (loss), net of tax
			before reclassification adjustment⁽³⁾		50.3		-70.4		-20.1
		Amounts reclassified from accumulated
			other comprehensive income (loss), net of tax⁽⁴⁾		-2		1.7		-0.3
	Net other comprehensive income (loss), net of tax				48.3		-68.7		-20.4

	Balance, December 31, 2014			$	221.5	$	-107.2	$	114.3

	Net of tax benefit of $111.1 million for net unrealized losses on fixed maturity securities and net of tax expense of $22.2 million for employee benefits.
	Net of tax benefits of $3.1 million for net unrealized gains on fixed maturity securities and $3.2 million for employee benefits, respectively.
	Net of tax expense of $24.6 million for net unrealized gains on fixed maturity securities and net of tax benefit of $37.9 million for employee benefits.
	Net of tax benefit of $1.1 million for net unrealized gains on fixed maturity securities and net of tax expense of $0.9 million for employee benefits.

Severance_Lease_Terminations_A1

Severance, Lease Terminations And Transition Costs (Tables)	12 Months Ended
Severance, Lease Terminations And Transition Costs (Tables)	Dec. 31, 2014
Severance, Lease Terminations, And Transition Costs [Abstract]
Severance Lease Terminations And Transition Costs Schedule Of Expenses Incurred			Year ended December 31, 2014
			Beginning						Ending
			Accrued		Charged to				Accrued
	(In millions)		Liability		Expense, Net		Expenditures		Liability

	Severance		$	0.2	$	-0.2	$	---	$	---

		Total severance	$	0.2	$	-0.2	$	---	$	---


			Year 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			---		1.3		1.3		---
	Lease terminations			0.3		---		0.3		---

		Total severance, transition costs and lease terminations	$	0.4	$	4.2	$	4.4	$	0.2

Quarterly_Financial_Informatio1

Quarterly Financial Information (Tables)	12 Months Ended
Quarterly Financial Information (Tables)	Dec. 31, 2014
Quarterly Financial Information [Abstract]
Financial Information By Calendar Quarter			2014
	(In millions—except per share data)		4th Quarter		3rd Quarter		2nd Quarter		1st Quarter

	Premiums		$	515.8	$	507.3	$	519.2	$	510.1
	Administrative fees			33.8		32.8		32.6		31.6
	Net investment income			153.4		147.1		149.8		150.6
	Net capital losses			-7.2		-5.2		-0.5		-1.1

		Total revenues		695.8		682		701.1		691.2
	Benefits to policyholders			394.1		360.8		426.2		401.1
	Net income			56.2		71.1		41.9		50.1


	Net income per common share:
		Basic	$	1.33	$	1.66	$	0.97	$	1.14
		Diluted		1.32		1.65		0.96		1.13


			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

Summary_Of_Significant_Account3

Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Tax-advantaged investments	$296.30	$192.40
Accumulated depreciation, Real estate	12	13.4
Depreciation expense	17.8	19.9	24.1
Percentage of corporate headquarters leased to non-affiliated tenants	34.20%	33.80%	33.30%
Advance premiums	188.3	186.1
Premiums On Deposit And Experienced Rated Refunds	187	193.5
Low Range decrease In Retained Earnings For Prospective Application Of New Accounting Principle	15
High range of the estimated decrease in retained earnings for prospective application of a new accounting principle	20
Prospective Accplication of Accounting Pronouncement Change in Net Income	13
Real estate, net and Policy loans	37	65.7
Impairment on real estate owned	$5.20	$8.70	$3
Maximum [Member] \| Real Estate Investment [Member]
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Useful life	40 years
Minimum [Member] \| Real Estate Investment [Member]
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Useful life	30 years
Properties
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Useful life	40 years
Equipment [Member] \| Maximum [Member]
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Useful life	10 years
Equipment [Member] \| Minimum [Member]
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Useful life	3 years
Software [Member] \| Maximum [Member]
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Useful life	5 years
Software [Member] \| Minimum [Member]
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Useful life	3 years
Software [Member] \| Customer Lists [Member]
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Intangible Assets, Useful Life	6 years 6 months 0 days
Minnesota Life [Member] \| Value Of Business Acquired [Member] \| Maximum [Member]
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Intangible Assets, Useful Life				30 years 0 months 0 days
TIAA [Member] \| Maximum [Member]
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Intangible Assets, Useful Life				20 years 0 months 0 days
Group Insurance [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] \| Properties \| Value Of Business Acquired [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] \| Properties \| Value Of Business Acquired [Member] \| Minimum [Member]
Organization, Principles Of Consolidation And Basis Of Presentation [Line Items]
Intangible Assets, Useful Life				20 years 0 months 0 days
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] \| Software [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.	76.00%
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.	54.00%
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.	93.00%
Individual Annuities [Member] \| Individual Disability Insurance Policies [Member] \| Equipment [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 Annuities [Member] \| Individual Disability Insurance Policies [Member] \| Equipment [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%

Summary_Of_Significant_Account4

Summary Of Significant Accounting Policies (Property And Equipment And Accumulated Depreciation) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Summary Of Significant Accounting Policies [Abstract]
Home office properties	$139.40	$136.90
Office furniture and equipment	48.6	47.9
Capitalized software	173	169.4
Leasehold improvements	14.9	13.9
Property and equipment, gross	375.9	368.1
Less: accumulated depreciation	296.6	283.4
Property and equipment, net	$79.30	$84.70

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, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net Income Per Common Share [Abstract]
Net income	$56.20	$71.10	$41.90	$50.10	$65	$59	$57.70	$46.80	$219.30	$228.50	$138.50
Basic weighted-average common shares outstanding									43,018,215	44,243,364	44,283,771
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Diluted weighted-average common shares outstanding									43,455,136	44,527,405	44,359,891
Net income per basic common share	$1.33	$1.66	$0.97	$1.14	$1.48	$1.33	$1.30	$1.05	$5.10	$5.16	$3.13
Net income per diluted common share	$1.32	$1.65	$0.96	$1.13	$1.46	$1.32	$1.30	$1.05	$5.05	$5.13	$3.12
Antidilutive shares not included in net income per diluted common share calculation									50,236	292,750	2,220,045
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dilutive shares from share based compensation									342,791	194,978	74,232
Stock Award Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dilutive shares from share based compensation									94,130	89,063	1,888

ShareBased_Compensation_Narrat

Share-Based Compensation (Narrative-Options) (Details) (Stock Incentive 2002 Plan [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
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	2,694,980
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	$5,500,000
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	$23.29	$16.15	$13.73
Total intrinsic value of the options exercised	5,900,000	14,400,000	3,200,000
Amount received from the exercise of stock options	10,900,000	50,200,000	7,600,000
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	3,600,000	1,100,000
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, 2014	Dec. 31, 2013	Dec. 31, 2012
Performance Shares Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards granted during period	77,634	129,172	179,818
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%
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards granted during period	48,294	59,823
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	2,694,980
Stock Incentive 2002 Plan [Member] \| Stock Award Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available issuance as stock award grants	1,076,051
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	8,846		9,899
Additional compensation cost assuming maximum payout of outstanding performance-based stock awards	7,700,000
Additional compensation cost assuming a target payout of outstanding performance-based stock awards	2,100,000
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	2,800,000
Share Based Compensation Arrangement By Share Based Payment Award OptionsTotalCompensation Cost Not Yet Recognized Weighted Average Period	1 year 8 months 12 days
Stock Incentive 2002 Plan [Member] \| Director Stock Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year 0 months 0 days
Issued under share-based compensation plans net, shares	17,294	20,099	9,489
Weighted average fair value of shares issued for vested stock grants	45.74	44.12	36.4
Non-employee director annual compensation in common stock, fair value	100,000	100,000	50,000

Share_Based_Compensation_Narra

Share Based Compensation (Narratvie-ESPP) (Details) (USD $)	12 Months Ended
Share Based Compensation (Narratvie-ESPP) (Details) (USD $)	Dec. 31, 2014
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	1,378,369
Employee share purchase plan offering period, months	0 years 6 months 0 days
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, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-Based Compensation [Abstract]
Compensation cost	$8.10	$8.30	$6.70
Related income tax benefit	$2.80	$2.90	$2.30

ShareBased_Compensation_Summar

Share-Based Compensation (Summary Of Option Activity And Options Outstanding And Exercisable) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-Based Compensation [Abstract]
Options, Outstanding, beginning balance	1,655,094	2,704,168	2,784,361
Options, Granted	151,060	211,367	268,033
Options, Exercised	-261,208	-1,214,399	-294,226
Options, Forfeited	-4,218	-31,211	-16,300
Options, Expired	0	-14,831	-37,700
Options, Outstanding, ending balance	1,540,728	1,655,094	2,704,168	2,784,361
Vested or expected to be vested	1,524,736
Fully vested and exercisable	1,220,891
Weighted-Average Exercise Price, Outstanding, beginning of period	$43.02	$42.17	$40.84
Weighted-Average Exercise Price, Granted	$64.18	$44.27	$38.09
Weighted-Average Exercise Price, Exercised	$41.64	$41.37	$25.67
Weighted-Average Exercise Price, Forfeited	$48.55	$47.13	$39.56
Weighted-Average Exercise Price, Expired	$0	$40.34	$45.06
Weighted-Average Exercise Price, Outstanding, end of period	$45.31	$43.02	$42.17	$40.84
Weighted-Average Exercise Price, Vested or expected to be vested	$45.25
Weighted-Average Exercise Price, Fully vested and exercisable	$43.85
Weighted-Average Remaining Contractual Terms (Years)	5 years 4 months 24 days	5 years 7 months 6 days	4 years 6 months 0 days	5 years 1 month 6 days
Weighted-Average Remaining Contractual Terms (Years), Vested or expected to be vested	5 years 4 months 24 days
Weighted-Average Remaining Contractual Terms (Years), Exercisable	4 years 7 months 6 days
Total Intrinsic Value, Outstanding, beginning of period	$38,455,709	$2,887,006	$5,947,355
Total Intrinsic Value, Outstanding, end of period	37,827,108	38,455,709	2,887,006	5,947,355
Total Intrinsic Value, Vested or expected to be vested	37,523,747
Total Intrinsic Value, Fully vested and exercisable	$31,759,884

ShareBased_Compensation_Weight

Share-Based Compensation (Weighted-Average Assumptions Used To Determine Fair Value Of Option Grants) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-Based Compensation [Abstract]
Dividend yield	1.78%	2.25%	2.36%
Expected stock price volatility	43.15%	45.86%	47.30%
Risk-free interest rate	1.81%	1.31%	1.02%
Expected option lives	6 years 0 months 0 days	6 years 2 months 12 days	5 years 10 months 24 days

ShareBased_Compensation_Summar1

Share-Based Compensation (Summary Of Activity Of Performance-Based Restricted Shares And Cash Performance Units Outstanding) (Details) (Restricted Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested balance, Beginning of period	56,766
Granted	48,294	59,823
Vested	0	0
Forfeited	685	3,057
Unvested balance, Ending	104,375	56,766
Unvested balance, Weighted-Average Grant Date Fair Value, beginning of period	$38.56
Unvested balance, Weighted-Average Grant Date Fair Value, end of period	$63.54	$38.56

ShareBased_Compensation_Summar2

Share-Based Compensation (Summary Of Activity Of Performance Shares Outstanding) (Details) (Performance Shares Member, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Performance Shares Member
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested balance, Beginning of period	297,282	296,796	190,968
Granted	77,634	129,172	179,818
Vested	-54,076	-13,964	-9,200
Forfeited	-118,968	-114,722	-64,790
Unvested balance, Ending	201,872	297,282	296,796
Unvested balance, Weighted-Average Grant Date Fair Value, beginning of period	$40.34	$43.14	$44.05
Unvested balance, Weighted-Average Grant Date Fair Value, end of period	$48.41	$40.34	$43.14

ShareBased_Compensation_Assump

Share-Based Compensation (Assumptions Used To Determine The Fair Value Of ESPP Embedded Option) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Expected option lives	6 years 0 months 0 days	6 years 2 months 12 days	5 years 10 months 24 days
Employee Stock Purchase 1999 Plan [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Dividend yield, minimum	1.80%	1.69%	2.38%
Dividend yield, maximum	1.84%	2.44%	3.06%
Expected stock price volatility, minimum	21.78%	17.43%	27.80%
Expected stock price volatility, maximum	22.40%	17.58%	49.09%
Risk-free interest rate, minimum	0.03%	0.07%	0.06%
Risk-free interest rate, maximum	0.06%	0.11%	0.13%
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, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$8.10	$8.30	$6.70
Related income tax benefit	2.8	2.9	2.3
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	$6.52	$4.16	$9.02
Compensation cost	0.3	0.3	1.4
Related income tax benefit	$0.10	$0.10	$0.50

Retirement_Benefits_Narrative_

Retirement Benefits (Narrative) (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated prior service cost (credit) will be amortized from accumulated other comprehensive loss into net periodic benefit cost	($6.90)	($0.40)
Employer contributions to pension plans	15	0	10
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
Employee benefit plans	92.5	33.7	81
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	0.9	0.7	0.3
Employer contributions for medical costs	0.5	0.4	0.3
Expected contributions to defined benefit plans in the upcoming year	0.8
Projected discounted cash flow obligation for postretirement benefit plan	24.7	17.6
Plan assets expected to be returned	None
Employee benefit plans	2.9	-1	-12
Supplemental Employee Retirement Plan Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Expenses towards non-qualified supplemental retirement plan	3.9	3.1	1.9
Other liabilities for non-qualified plan	42.8	31.1
Employee benefit plans	11.7	5.7	4.7
Deferred Compensation Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions to the deferred compensation plans	10.7	9.9	9.9
Liability for the plans, unfunded portion	$12.60	$11.60

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of the year	($408.40)	($418.50)	($371.60)
Service cost	-8.4	-10.2	-9.7
Interest cost, net periodic benefit	-19.3	-16.7	-16.5
Actuarial loss	-87.1	26	-29.7
Benefits Paid	12.2	11	9
Benefit obligation at end of the year	-511	-408.4	-418.5
Fair value of plan assets at beginning of the year	440.4	386	349.7
Actual return on plan assets	28.8	65.4	35.4
Employer contributions	15	0	10
Benefits paid and estimated expenses	-12.3	-11	-9.1
Fair value of plan assets at end of the year	471.9	440.4	386
Funded status at end of the year	($39.10)	$32	($32.50)

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, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Pension [Member]
Projected benefit obligation	$511	$408.40	$418.50	$371.60
Accumulated benefit obligation	471.9	374.2	386.5
Fair value of plan assets	$471.90	$440.40	$386	$349.70

Retirement_Benefits_Amounts_Re

Retirement Benefits (Amounts Recognized In Accumulated Other Comprehensive Loss) (Details) (Defined Benefit Pension [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Loss	$90.60	$31.40	$78.30
Prior service cost	1.9	2.3	2.7
Total recognized in accumulated other comprehensive loss	$92.50	$33.70	$81

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$8.50	$10.30	$9.80
Interest cost	19.3	16.7	16.5
Expected return on plan assets	-33.4	-29.3	-26.5
Amortization of prior service cost	0.6	0.6	0.6
Amortization of net actuarial loss	0.7	9.9	8.3
Net periodic benefit cost	-4.3	8.2	8.7
Net loss	91.8	-62.2	20.9
Prior service cost	0	0	0
Amortization of prior service cost	-0.7	-0.6	-0.6
Amortization of net actuarial loss	-0.7	-9.9	-8.3
Total recognized in other comprehensive income	90.4	-72.7	12
Total recognized in net periodic benefit cost and other comprehensive income	$86.10	($64.50)	$20.70
Assumptions used for net periodic benefit cost, Discount rate	4.75%	4.00%	4.50%
Assumptions used for net periodic benefit cost, Expected return on plan assets	7.71%	7.70%	7.69%
Assumptions used for net periodic benefit cost, Rate of compensation increase	3.50%	3.00%	3.25%
Assumptions used to determine benefit obligations, Discount rate	4.00%	4.75%	4.00%
Assumptions used to determine benefit obligations, Rate of compensation increase	3.00%	3.50%	3.00%

Retirement_Benefits_Expected_B

Retirement Benefits (Expected Benefit Payments For Pension Plans) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
2015	$13.50
2016	14.6
2017	15.8
2018	16.8
2019	18
2020-2024	111.1
Defined Benefit Pension [Member]
Defined Benefit Plan Disclosure [Line Items]
2015	13.5
2016	14.6
2017	15.8
2018	16.8
2019	18
2020-2024	$111.10

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, 2014	Dec. 31, 2013
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	50.30%	49.00%
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation	50.00%
Actual asset allocation	49.70%	51.00%

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, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	$471.90	$440.40	$386	$349.70
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	237.3	215.9
Fair Value Inputs Level1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	237.3	215.9
Fair Value Inputs Level1 [Member] \| Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	237.3	215.9
Fair Value Inputs Level2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	234.6	224.5
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	47.3	43
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	47.3	43
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	74	64.7
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	74	64.7
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	24.2	21.7
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	24.2	21.7
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	71.5	64.8
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	71.5	64.8
Pooled Separate Account Funds Foreign [Member] \| Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	20.3	21.7
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	20.3	21.7
Stable Asset Fund [Member] \| Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	234.6	224.5
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	$234.60	$224.50

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation at beginning of the year	($17.60)	($23.90)	($41)
Service cost	0	0	-1
Interest cost, net periodic benefit	-0.8	-1.1	-1.8
Plan amendments	0	0.8	25.2
Actuarial loss	-7.3	5.2	-5.9
Benefits Paid	1	1.4	0.6
Benefit obligation at end of the year	-24.7	-17.6	-23.9
Fair value of plan assets at beginning of the year	19.3	21.6	20.7
Actual return on plan assets	2	-1.6	1.2
Employer contributions	0.9	0.7	0.3
Benefits paid and estimated expenses	-1	-1.4	-0.6
Fair value of plan assets at end of the year	21.2	19.3	21.6
Funded status at end of the year	($3.50)	$1.70	($2.30)

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, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Loss	$2.90	($1)	$5.10
Prior service cost	0	0	-17.1
Total recognized in accumulated other comprehensive loss	$2.90	($1)	($12)

Retirement_Benefits_Assumed_He

Retirement Benefits (Assumed Health Care Cost Trend Rates For Next Year) (Details)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
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%	[1]	4.50%	[1]
Medical [Member]
Assumed Health Care Cost Trend Rates For Next Year [Line Items]
Assumed health care cost trend rates for next year	6.90%		7.10%
Prescriptions [Member]
Assumed Health Care Cost Trend Rates For Next Year [Line Items]
Assumed health care cost trend rates for next year	7.20%		7.50%
Health Maintenance Organization [Member]
Assumed Health Care Cost Trend Rates For Next Year [Line Items]
Assumed health care cost trend rates for next year	5.70%		6.00%

[1]	*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:

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, 2014
Retirement Benefits [Abstract]
Effect on total of service and interest cost, 1% Point Increase	$0.10
Effect on postretirement benefit obligation, 1% Point Increase	2.8
Effect on total of service and interest cost, 1% Point Decrease	-0.1
Effect on postretirement benefit obligation, 1% Point Decrease	($2.30)

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$0	$0	$1
Interest cost	0.8	1	1.8
Expected return on plan assets	-0.8	-0.8	-0.8
Amortization of prior service cost	0	-26.3	-0.4
Amortization of net actuarial loss	0	5.7	0
Curtailment loss	0	0	0
Net periodic benefit cost	0	-20.4	1.6
Net loss	-5.9	-3.3	5.5
Prior service cost	0	0	-25.2
Amortization of prior service cost	0	26.3	0.4
Amortization of net actuarial loss	0	-5.8	0
Total recognized in other comprehensive income	-5.9	17.2	-19.3
Total recognized in net periodic benefit cost and other comprehensive income	($5.90)	($3.20)	($17.70)
Assumptions used for net periodic benefit cost, Discount rate	4.80%	4.00%	4.50%
Assumptions used for net periodic benefit cost, Expected return on plan assets	4.20%	4.20%	4.20%
Assumptions used to determine benefit obligations, Discount rate	4.10%	4.80%	4.00%

Retirement_Benefits_Expected_B1

Retirement Benefits (Expected Benefit Payments For Postretirement Benefit Plan) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
2015	$13.50
2016	14.6
2017	15.8
2018	16.8
2019	18
2020-2024	111.1
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
2015	1.5
2016	1.5
2017	1.4
2018	1.4
2019	1.3
2020-2024	$6.40

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, 2014	Dec. 31, 2013
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	96.70%	96.20%
Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Target asset allocation	5.00%
Actual asset allocation	3.30%	3.80%

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, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	$21.20	$19.30	$21.60	$20.70
Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	17.9	16.8
Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	2.6	1.8
Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	0.7	0.7
Fair Value Inputs Level1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	0.7	0.7
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	0.7
Fair Value Inputs Level2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	20.5	18.6
Fair Value Inputs Level2 [Member] \| Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	17.9	16.8
Fair Value Inputs Level2 [Member] \| Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	2.6	1.8
Fair Value Inputs Level2 [Member] \| Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total pension plan assets are recorded at fair value	$0

Segments_Intersegment_Administ

Segments (Intersegment Administrative Fee Revenues) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Intersegment Revenues [Line Items]
Administrative fees	$33.80	$32.80	$32.60	$31.60	$32	$30.50	$30.40	$28.70	$130.80	$121.60	$114.70
Intersegment [Member]
Intersegment Revenues [Line Items]
Administrative fees									$19.30	$18.60	$17.90

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, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Total Revenue By Segment And Product Line [Line Items]
Premiums	$515.80	$507.30	$519.20	$510.10	$528.60	$524.40	$535.10	$536.20	$2,052.40	$2,124.30	$2,163.90
Administrative fees	33.8	32.8	32.6	31.6	32	30.5	30.4	28.7	130.8	121.6	114.7
Net investment income	153.4	147.1	149.8	150.6	160.8	155.8	154.1	159.2	600.9	629.9	628.5
Insurance Services [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									2,041.90	2,117.40	2,157.20
Administrative fees									16.7	15.3	13.9
Net investment income									299.5	320.6	339.7
Individual Disability [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									199.1	190.5	176.6
Administrative fees									0.2	0.2	0.2
Net investment income									52.1	52.8	53.7
Employee Benefits [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									1,842.80	1,926.90	1,980.60
Administrative fees									16.5	15.1	13.7
Net investment income									247.4	267.8	286
Employee Benefits [Member] \| Group Life And Add [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									808.6	849.7	883.7
Employee Benefits [Member] \| Group Long Term Disability [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									753.8	783	801.4
Employee Benefits [Member] \| Group Short Term Disability [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									219	229	212.6
Employee Benefits [Member] \| Group Other [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									79	78.3	78.9
Employee Benefits [Member] \| Experience Rated Refunds [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									-17.6	-13.1	4
Asset Management Segment [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									10.5	6.9	6.7
Administrative fees									133.4	124.9	118.8
Net investment income									283.3	293.2	278.6
Asset Management Segment [Member] \| Retirement Plans [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									1.7	2.2	1.9
Administrative fees									99.7	93.3	88
Net investment income									113.2	103.2	94.9
Asset Management Segment [Member] \| Individual Annuities [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									8.8	4.7	4.8
Net investment income									155.9	177.2	170.6
Asset Management Segment [Member] \| Other Financial Services Businesses [Member]
Total Revenue By Segment And Product Line [Line Items]
Administrative fees									33.7	31.6	30.8
Net investment income									14.2	12.8	13.1
Other Category [Member]
Total Revenue By Segment And Product Line [Line Items]
Premiums									0	0	0
Administrative fees									-19.3	-18.6	-18
Net investment income									$18.10	$16.10	$10.20

Segments_PTOI_and_Assets_Addit

Segments (PTOI and Assets Additional Information) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting, Revenue Reconciling Item [Line Items]
Income Before Income Taxes	$286.90	$313	$183.40
Total Assets	22,729.90	21,393.30	19,791.30
Insurance Services [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Income Before Income Taxes	254.7	272.4	179.8
Total Assets	8,352	8,088.10	8,250.80
Employee Benefits [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Income Before Income Taxes	201.8	216.4	129.8
Total Assets	5,952.50	5,744.70	5,991.40
Individual Disability [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Income Before Income Taxes	52.9	56	50
Total Assets	2,399.50	2,343.40	2,259.40
Asset Management Segment [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Income Before Income Taxes	77.9	79.3	64
Total Assets	14,025.60	12,777.10	11,046
Other Category [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Income Before Income Taxes	-45.7	-38.7	-60.4
Total Assets	$352.30	$528.10	$494.50

Segments_Segment_Information_D

Segments (Segment Information) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums	$515.80	$507.30	$519.20	$510.10	$528.60	$524.40	$535.10	$536.20	$2,052.40	$2,124.30	$2,163.90
Administrative fees	33.8	32.8	32.6	31.6	32	30.5	30.4	28.7	130.8	121.6	114.7
Net investment income	153.4	147.1	149.8	150.6	160.8	155.8	154.1	159.2	600.9	629.9	628.5
Net capital losses	-7.2	-5.2	-0.5	-1.1	-2.8	-8.7	-2.6	-1.6	-14	-15.7	-8.7
Total revenues	695.8	682	701.1	691.2	718.6	702	717	722.5	2,770.10	2,860.10	2,898.40
Benefits to policyholders	394.1	360.8	426.2	401.1	394.5	395	424.1	441.8	1,582.20	1,655.40	1,793
Interest credited									164.6	176.4	171.3
Operating expenses									470.6	442.6	470.5
Commissions and bonuses									207.2	207.9	203.7
Premium taxes									31.5	35.3	37.5
Interest expense									31.8	34.4	39.9
Net increase in deferred acquisition costs, value of business acquired and other intangible assets									-4.7	-4.9	-0.9
Total benefits and expenses									2,483.20	2,547.10	2,715
Income (loss) before income taxes									286.9	313	183.4
Total assets	22,729.90				21,393.30				22,729.90	21,393.30	19,791.30
Insurance Services [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums									2,041.90	2,117.40	2,157.20
Administrative fees									16.7	15.3	13.9
Net investment income									299.5	320.6	339.7
Net capital losses										0	0
Total revenues									2,358.10	2,453.30	2,510.80
Benefits to policyholders									1,561.40	1,637.70	1,773.30
Interest credited									2.6	4.3	4.2
Operating expenses									349.2	340	349.1
Commissions and bonuses									170.6	174.2	172.7
Premium taxes									31.5	35.2	37.5
Net increase in deferred acquisition costs, value of business acquired and other intangible assets									-11.9	-10.5	-5.8
Total benefits and expenses									2,103.40	2,180.90	2,331
Income (loss) before income taxes									254.7	272.4	179.8
Total assets	8,352				8,088.10				8,352	8,088.10	8,250.80
Employee Benefits [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums									1,842.80	1,926.90	1,980.60
Administrative fees									16.5	15.1	13.7
Net investment income									247.4	267.8	286
Net capital losses										0	0
Total revenues									2,106.70	2,209.80	2,280.30
Benefits to policyholders									1,431.40	1,515.90	1,657.10
Interest credited									2.6	4.3	4.2
Operating expenses									321.4	313.3	323.6
Commissions and bonuses									122.6	126.7	125.1
Premium taxes									27.9	31.3	33.6
Net increase in deferred acquisition costs, value of business acquired and other intangible assets									-1	1.9	6.9
Total benefits and expenses									1,904.90	1,993.40	2,150.50
Income (loss) before income taxes									201.8	216.4	129.8
Total assets	5,952.50				5,744.70				5,952.50	5,744.70	5,991.40
Individual Disability [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums									199.1	190.5	176.6
Administrative fees									0.2	0.2	0.2
Net investment income									52.1	52.8	53.7
Net capital losses										0	0
Total revenues									251.4	243.5	230.5
Benefits to policyholders									130	121.8	116.2
Interest credited										0	0
Operating expenses									27.8	26.7	25.5
Commissions and bonuses									48	47.5	47.6
Premium taxes									3.6	3.9	3.9
Net increase in deferred acquisition costs, value of business acquired and other intangible assets									-10.9	-12.4	-12.7
Total benefits and expenses									198.5	187.5	180.5
Income (loss) before income taxes									52.9	56	50
Total assets	2,399.50				2,343.40				2,399.50	2,343.40	2,259.40
Asset Management Segment [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums									10.5	6.9	6.7
Administrative fees									133.4	124.9	118.8
Net investment income									283.3	293.2	278.6
Net capital losses										0	0
Total revenues									427.2	425	404.1
Benefits to policyholders									20.8	17.7	19.7
Interest credited									162	172.1	167.1
Operating expenses									122.7	116.5	117.4
Commissions and bonuses									36.6	33.7	31
Premium taxes									0	0.1	0
Net increase in deferred acquisition costs, value of business acquired and other intangible assets									7.2	5.6	4.9
Total benefits and expenses									349.3	345.7	340.1
Income (loss) before income taxes									77.9	79.3	64
Total assets	14,025.60				12,777.10				14,025.60	12,777.10	11,046
Other Category [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Premiums									0	0	0
Administrative fees									-19.3	-18.6	-18
Net investment income									18.1	16.1	10.2
Net capital losses									-14	-15.7	-8.7
Total revenues									-15.2	-18.2	-16.5
Operating expenses									-1.3	-13.9	4
Interest expense									31.8	34.4	39.9
Total benefits and expenses									30.5	20.5	43.9
Income (loss) before income taxes									-45.7	-38.7	-60.4
Total assets	$352.30				$528.10				$352.30	$528.10	$494.50

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, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Administrative fees	$33.80	$32.80	$32.60	$31.60	$32	$30.50	$30.40	$28.70	$130.80	$121.60	$114.70
Net investment income	153.4	147.1	149.8	150.6	160.8	155.8	154.1	159.2	600.9	629.9	628.5
Net capital losses	-7.2	-5.2	-0.5	-1.1	-2.8	-8.7	-2.6	-1.6	-14	-15.7	-8.7
Total revenues	695.8	682	701.1	691.2	718.6	702	717	722.5	2,770.10	2,860.10	2,898.40
Interest expense									31.8	34.4	39.9
Operating expenses									470.6	442.6	470.5
Total expenses									2,483.20	2,547.10	2,715
Income before income taxes									286.9	313	183.4
Income tax benefit									67.6	84.5	44.9
Net income	56.2	71.1	41.9	50.1	65	59	57.7	46.8	219.3	228.5	138.5
Unrealized Holding Gain (Loss) on Securities, Tax									24.6	-111.1	38.3
Other comprehensive income									-20.4	-174.6	74.2
Comprehensive income									198.9	53.9	212.7
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Net investment income									12.9	13.2	5
Net capital losses									-0.8	0.2	0.1
Total revenues									12.1	13.4	5.1
Interest expense									31.7	34.2	39.7
Operating expenses									0.5	0.9	4.5
Total expenses									32.2	35.1	44.2
Income before income taxes									-20.1	-21.7	-39.1
Income tax benefit									-6.1	-7.7	-14.2
Equity in net income of subsidiaries									233.3	242.5	163.4
Net income									219.3	228.5	138.5
Other comprehensive income									-57.5	47	1.7
SubsidiariesMember
Condensed Financial Statements, Captions [Line Items]
Other comprehensive income									$37.10	($221.60)	$72.50

Parent_Holding_Company_Condens3

Parent Holding Company Condensed Financial Information (Condensed Balance Sheets) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$251.10	$379.30	$160.70	$138.40
Other assets	129.4	127.9
Total assets	22,729.90	21,393.30	19,791.30
Short-term debt	1.1	1.5
Long-term debt	503.9	551.9
Other liabilities	440.1	330.7
Total liabilities	20,558.10	19,240.50
Total shareholders' equity	2,171.80	2,152.80	2,169	1,990.40
Total liabilities and shareholders' equity	22,729.90	21,393.30
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	70.5	125.2	39.7	34.5
Investment in subsidiaries	2,317.90	2,252.90
Receivable from subsidiaries	0.9	1.5
Notes Receivable, Affiliates	250	250
Other assets	77.9	80.3
Total assets	2,717.20	2,709.90
Long-term debt	502.9	550
Other liabilities	42.5	7.1
Total liabilities	545.4	557.1
Total shareholders' equity	2,171.80	2,152.80
Total liabilities and shareholders' equity	$2,717.20	$2,709.90

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating:
Net income	$219.30	$228.50	$138.50
Other, net	-17.8	-29.4	51.4
Net cash provided by operating activities	238.2	279.6	375.7
Investing:
Net cash used in investing activities	-616.8	-504.3	-763
Financing:
Repayment of senior debt	47.1	0	250
Issuance of debt, net of issuance costs	0	0	246.7
Dividends paid on common stock	-54.7	-48.5	-41.3
Net cash provided by financing activities	250.4	443.3	409.6
(Decrease) increase in cash and cash equivalents	-128.2	218.6	22.3
Cash and cash equivalents, beginning of period	379.3	160.7	138.4
Cash and cash equivalents, end of period	251.1	379.3	160.7
Parent Company [Member]
Operating:
Net income	219.3	228.5	138.5
Equity in net income of subsidiaries	-233.3	-242.5	-163.4
Dividends received from subsidiaries	423	147	328.7
Other, net	-13.4	23.7	-2.5
Net cash provided by operating activities	395.6	156.7	301.3
Investing:
Capital contributions to subsidiaries	-240.3	-0.7	-14.5
Return of capital from subsidiaries	27	7.8	7.3
Surplus note receivable from subsidiary	0	0	-250
Receivables from subsidiaries	0.3	-0.3	3.4
Investment securities and other	-2.8	0.2	1.4
Net cash used in investing activities	-215.8	7	-252.4
Financing:
Issuance and repurchase of common stock, net	-132.7	-29.7	0.9
Repayment of senior debt	47.1	0	250
Issuance of debt, net of issuance costs	0	0	246.7
Dividends paid on common stock	-54.7	-48.5	-41.3
Net cash provided by financing activities	-234.5	-78.2	-43.7
(Decrease) increase in cash and cash equivalents	-54.7	85.5	5.2
Cash and cash equivalents, beginning of period	125.2	39.7	34.5
Cash and cash equivalents, end of period	$70.50	$125.20	$39.70

Income_Taxes_Narrative_Details

Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2012	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Federal corporate tax rate	35.00%
Carrying forward net operating losses	$54
Valuation Allowance, Other Assets	1.1
Valuation Allowance	8.4
Deferred tax assets, valuation allowance	9.5	3.1	9.5
Tax years open for examination	the Company is subject to examination by the IRS for the years 2011 through 2014
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Unutilized NOLs expiration date	31-Dec-33
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	13.2
State and municipalities [Member] \| Maximum [Member]
Operating Loss Carryforwards [Line Items]
Unutilized NOLs expiration date	31-Dec-33
Prior Business Combinations [Member]
Operating Loss Carryforwards [Line Items]
Carrying forward net operating losses	$46
Prior Business Combinations [Member] \| Maximum [Member]
Operating Loss Carryforwards [Line Items]
Unutilized NOLs expiration date	31-Dec-25
Prior Business Combinations [Member] \| Minimum [Member]
Operating Loss Carryforwards [Line Items]
Unutilized NOLs expiration date	31-Dec-20

Income_Taxes_Provision_For_Inc

Income Taxes (Provision For Income Taxes) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes Disclosure [Abstract]
Current	$56.90	$71.10	$38.50
Deferred	10.7	13.4	6.4
Total income tax provision	$67.60	$84.50	$44.90

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes Disclosure [Abstract]
Tax at federal corporate rate of 35%	$100.40	$109.60	$64.20
(Decrease) increase in rate resulting from Tax exempt interest	0	0	-0.1
(Decrease) Increase in rate resulting from Dividends received deduction	-4.4	-3.6	-3.6
(Decrease) Increase in rate resulting from State income taxes, net of federal benefit	2.2	1.3	0.2
(Decrease) Increase in rate resulting from Federal tax credits	-33.7	-24.9	-17.4
(Decrease) increase in rate resulting from Other	3.1	2.1	1.6
Total income tax provision	$67.60	$84.50	$44.90

Income_Taxes_Net_Deferred_Tax_

Income Taxes (Net Deferred Tax Liability) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes Disclosure [Abstract]
Policyholder liabilities	$9.60	$1.20	$1.80
Compensation and benefit plans	49.9	12.6	44
Loss carryforwards	46.6	49.7	51.7
Investments	30.4	45.6	35.8
Other	1.3	3.5	2.2
Total deferred tax assets	137.8	112.6	135.5
Less: valuation allowances	-9.5	-9.5	-3.1
Net deferred tax assets	128.3	103.1	132.4
Net unrealized capital gains	116.8	95.7	210
Capitalized software	5.6	6.8	8.3
Deferred policy acquisition costs	67	63.5	59.7
Intangible assets	0	0.9	2
Other	2	0.9	0.5
Total deferred tax liabilities	191.4	167.8	280.5
Net deferred tax liability	($63.10)	($64.70)	($148.10)

Goodwill_Details

Goodwill (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Abstract]
Goodwill	$36	$36

Fair_Value_Narrative_Details

Fair Value (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value Measurement [Line Items]
Impact on interest credited during the period due to changes in Level 3 actuarial assumptions	($4)	($4.10)
Impaired recorded investment, with related allowance	74.2	87.7
Assets measured at fair value on a nonrecurring basis during the period and still held as of the balance sheet date	66.3	103.9
Related Allowance	23.8	25.9
Debt instrument, face amount	252.9
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	1.2	7.2
Assets measured at fair value on a nonrecurring basis during the period and still held as of the balance sheet date	10.3	35.2
Commercial Mortgage Loans [Member]
Fair Value Measurement [Line Items]
Assets measured at fair value on a nonrecurring basis during the period and still held as of the balance sheet date	$56	$68.70

Fair_Value_Estimated_Fair_Valu

Fair Value (Estimated Fair Value And The Carrying Value Of Each Financial Instrument) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	NumberOfDerivativeContracts	Dec. 31, 2013
Total fixed maturity securities-available-for-sale	$7,773.70	$7,120.50
Commercial mortgage loans, net	5,321.10	5,405.10
Separate account assets	7,179.80	6,393.20
Other policyholder funds	6,537.80	6,051.60
Short-term debt	1.1	1.5
Long-term debt	503.9	551.9
Level 3 [Member]
Separate account assets	7,179.80
Corporate Bond Securities [Member]
Total fixed maturity securities-available-for-sale	7,272.60	6,545.70
U S Government Agencies Debt Securities [Member]
Total fixed maturity securities-available-for-sale	300.1	353.2
U S States And Political Subdivisions [Member]
Total fixed maturity securities-available-for-sale	136.1	140.3
Foreign Government Debt [Member]
Total fixed maturity securities-available-for-sale	64.9	65.5
S And P Five Hundred Index Options [Member]
Total fixed maturity securities-available-for-sale		15.8
S And P Five Hundred Index Options Purchased Per Month	2
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Total fixed maturity securities-available-for-sale	7,773.70	7,120.50
Commercial mortgage loans, net	5,321.10	5,405.10
Interest Rate Swaps	4.7
Policy loans	2.2	2.5
Separate account assets		6,393.20
Index-based interest guarantees		67.6
Short-term debt	1.1	1.5
Long-term debt	503.9	551.9
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Corporate Bond Securities [Member]
Total fixed maturity securities-available-for-sale	7,272.60	6,545.70
Index-based interest guarantees	77
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| U S Government Agencies Debt Securities [Member]
Total fixed maturity securities-available-for-sale	300.1	353.2
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| U S States And Political Subdivisions [Member]
Total fixed maturity securities-available-for-sale	136.1	140.3
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Foreign Government Debt [Member]
Total fixed maturity securities-available-for-sale	64.9	65.5
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| S And P Five Hundred Index Options [Member]
Total fixed maturity securities-available-for-sale		15.8
Index-based interest guarantees	13.6
Carrying (Reported) Amount, Fair Value Disclosure [Member] \| Investment Type Contracts [Member]
Other policyholder funds	5,961.10	5,469.80
Estimate Of Fair Value Fair Value Disclosure [Member]
Total fixed maturity securities-available-for-sale	7,773.70	7,120.50
Commercial mortgage loans, net	6,021.50	5,769.60
Interest Rate Swaps	4.7
Policy loans	2.2	2.5
Separate account assets	7,179.80	6,393.20
Index-based interest guarantees		67.6
Short-term debt	1.5	1.9
Long-term debt	538.4	553.6
Estimate Of Fair Value Fair Value Disclosure [Member] \| Level 1 [Member]
Separate account assets	7,066.40	6,249.20
Estimate Of Fair Value Fair Value Disclosure [Member] \| Level 2 [Member]
Total fixed maturity securities-available-for-sale	7,684.70	6,988.70
Interest Rate Swaps	4.7
Separate account assets	113.4	144
Short-term debt	1.5	1.9
Long-term debt	538.4	553.6
Estimate Of Fair Value Fair Value Disclosure [Member] \| Level 3 [Member]
Total fixed maturity securities-available-for-sale	89	131.8
Commercial mortgage loans, net	6,021.50	5,769.60
Policy loans	2.2	2.5
Index-based interest guarantees		67.6
Estimate Of Fair Value Fair Value Disclosure [Member] \| Corporate Bond Securities [Member]
Total fixed maturity securities-available-for-sale	7,272.60	6,545.70
Index-based interest guarantees	77
Estimate Of Fair Value Fair Value Disclosure [Member] \| Corporate Bond Securities [Member] \| Level 2 [Member]
Total fixed maturity securities-available-for-sale	7,183.60	6,429.70
Estimate Of Fair Value Fair Value Disclosure [Member] \| Corporate Bond Securities [Member] \| Level 3 [Member]
Total fixed maturity securities-available-for-sale		116
Index-based interest guarantees	77
Estimate Of Fair Value Fair Value Disclosure [Member] \| U S Government Agencies Debt Securities [Member]
Total fixed maturity securities-available-for-sale	300.1	353.2
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	300.1	353.2
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		0
Estimate Of Fair Value Fair Value Disclosure [Member] \| U S States And Political Subdivisions [Member]
Total fixed maturity securities-available-for-sale	136.1	140.3
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	136.1	140.3
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		0
Estimate Of Fair Value Fair Value Disclosure [Member] \| Foreign Government Debt [Member]
Total fixed maturity securities-available-for-sale	64.9	65.5
Estimate Of Fair Value Fair Value Disclosure [Member] \| Foreign Government Debt [Member] \| Level 2 [Member]
Total fixed maturity securities-available-for-sale	64.9	65.5
Estimate Of Fair Value Fair Value Disclosure [Member] \| Foreign Government Debt [Member] \| Level 3 [Member]
Total fixed maturity securities-available-for-sale		0
Estimate Of Fair Value Fair Value Disclosure [Member] \| S And P Five Hundred Index Options [Member]
Total fixed maturity securities-available-for-sale		15.8
Index-based interest guarantees	13.6
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		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		15.8
Index-based interest guarantees	13.6
Estimate Of Fair Value Fair Value Disclosure [Member] \| Investment Type Contracts [Member]
Other policyholder funds	6,232.50	5,632.70
Estimate Of Fair Value Fair Value Disclosure [Member] \| Investment Type Contracts [Member] \| Level 3 [Member]
Other policyholder funds	$6,232.50	$5,632.70

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$102.60	$131.80	$94.50
S And P Five Hundred Index Options [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	13.6	15.8	11.3
Unobservable Inputs	(a)	(a)
Fair Value Measurements Significant Assumptions	Various assumptions	Various assumptions
Fair Value Measurements Valuation Techniques	Black-Scholes option pricing model	Black-Scholes option pricing model
Index Based Interest Guarantees [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	77	67.6	57.4
Fair Value Measurements Significant Assumptions	Expected future, Various assumptions	Expected future, Various assumptions
Fair Value Measurements Valuation Techniques	Discounted cash , Black-Scholes option pricing model	Discounted cash , Black-Scholes option pricing model
Index Based Interest Guarantees [Member] \| Various Assumptions [Member] \| Black Scholes Option Pricing Model [Member]
Unobservable Inputs	(a)	(a)
Index Based Interest Guarantees [Member] \| Various Assumptions [Member] \| Discounted Cash Flow [Member]
Unobservable Inputs	(b)	(b)
Index Based Interest Guarantees [Member] \| Various Assumptions [Member] \| Discounted Cash Flow [Member] \| Maximum [Member]
Unobservable Inputs	36%	36%
Index Based Interest Guarantees [Member] \| Various Assumptions [Member] \| Discounted Cash Flow [Member] \| Minimum [Member]
Unobservable Inputs	5%	5%
Index Based Interest Guarantees [Member] \| Expected Future Option Purchase [Member] \| Discounted Cash Flow [Member] \| Maximum [Member]
Unobservable Inputs	3%	6%
Index Based Interest Guarantees [Member] \| Expected Future Option Purchase [Member] \| Discounted Cash Flow [Member] \| Minimum [Member]
Unobservable Inputs	1%	1%
Commercial Mortgage Loans [Member]
Fair Value Measurements Significant Assumptions	Reduction on appraisal , Capitalization rate (c)	Reduction on appraisal , Capitalization rate (c)
Fair Value Measurements Valuation Techniques	Appraisals, Cash flows	Appraisals, Cash flows
Commercial Mortgage Loans [Member] \| Reduction On Appraisal [Member] \| Appraisals Member [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	56	68.7
Commercial Mortgage Loans [Member] \| Reduction On Appraisal [Member] \| Appraisals Member [Member] \| Maximum [Member]
Unobservable Inputs	37%	13%
Commercial Mortgage Loans [Member] \| Reduction On Appraisal [Member] \| Appraisals Member [Member] \| Minimum [Member]
Unobservable Inputs	0%	0%
Commercial Mortgage Loans [Member] \| Capitalization Rate [Member] \| CashFlowsMember [Member] \| Maximum [Member]
Unobservable Inputs	16%	16%
Commercial Mortgage Loans [Member] \| Capitalization Rate [Member] \| CashFlowsMember [Member] \| Minimum [Member]
Unobservable Inputs	7%	7%
Real Estate Owned [Member]
Fair Value Measurements Significant Assumptions	Reduction on appraisal	Reduction on appraisal
Fair Value Measurements Valuation Techniques	Appraisals	Appraisals
Real Estate Owned [Member] \| Reduction On Appraisal [Member] \| Appraisals Member [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$10.30	$35.20
Real Estate Owned [Member] \| Reduction On Appraisal [Member] \| Appraisals Member [Member] \| Maximum [Member]
Unobservable Inputs	11%	53%
Real Estate Owned [Member] \| Reduction On Appraisal [Member] \| Appraisals Member [Member] \| Minimum [Member]
Unobservable Inputs	0%	0%

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, 2014	Dec. 31, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning asset balance	$131.80	$94.50
Total Realized/Unrealized Gains (Losses) Included in Net Income	8.6	14.4
Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)	-3.8	6.2
Purchases	9.3	9.4
Issuance	0
Sales	0
Settlements	-20.1	-19.3
Transfers into Level 3	8.4	61.6
Transfers out of Level 3	-31.6	-35
Ending asset	102.6	131.8
U S Government Agencies Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning asset balance		1.1
Transfers out of Level 3		-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
Transfers out of Level 3		-1.7
Corporate Bond Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning asset balance	116	80.4
Total Realized/Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss)	-3.8	6.2
Transfers into Level 3	8.4	61.6
Transfers out of Level 3	-31.6	-32.2
Ending asset	89	116
S And P Five Hundred Index Options [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning asset balance	15.8	11.3
Total Realized/Unrealized Gains (Losses) Included in Net Income	8.6	14.4
Purchases	9.3	9.4
Settlements	-20.1	-19.3
Ending asset	13.6	15.8
Index Based Interest Guarantees [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total Realized/Unrealized Gains (Losses) Included in Net Income	-7.2	-9
Issuance	-12.2	-6
Settlements	-10	4.8
Beginning Liability	67.6	57.4
Ending Liability	$77	$67.60

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, 2014	Dec. 31, 2013
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	$4.30	$6.40
Index Based Interest Guarantees [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss) Included in Investment Income	($14)	($12.90)

Fair_Value_Assets_Measured_At_

Fair Value (Assets Measured At Fair Value On A Nonrecurring Basis) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Assets measured at fair value on a nonrecurring basis during the period and still held as of the balance sheet date	$66.30	$103.90
Level 3 [Member]
Assets measured at fair value on a nonrecurring basis during the period and still held as of the balance sheet date	66.3	103.9
Commercial Mortgage Loans [Member]
Assets measured at fair value on a nonrecurring basis during the period and still held as of the balance sheet date	56	68.7
Commercial Mortgage Loans [Member] \| Level 3 [Member]
Assets measured at fair value on a nonrecurring basis during the period and still held as of the balance sheet date	56	68.7
Real Estate Owned [Member]
Assets measured at fair value on a nonrecurring basis during the period and still held as of the balance sheet date	10.3	35.2
Real Estate Owned [Member] \| Level 3 [Member]
Assets measured at fair value on a nonrecurring basis during the period and still held as of the balance sheet date	$10.30	$35.20

Investments_Narrative_Details

Investments (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Investments [Line Items]
Callable bonds without a make-whole provision of fixed maturity available-for-sale securities, percentage	3.50%
Callable bonds without a make-whole provision of fixed maturity available-for-sale securities, amount	$275.10
Securities deposited for the benefit of policyholders in accordance with state regulations	7.2	7.4
Interest income recognized on impaired commercial mortgage loans	5.3	4.2	4.1
Cash received by the company as interest on impaired commercial mortgage loans	4.8	3.8	4
Commercial mortgage loans that were at least 60 days past due	8.6	15.2
60 day delinquency proportion of commercial mortgage loan portfolio	0.16%	0.28%
Total fixed maturity securities-available-for-sale	7,773.70	7,120.50
Total fixed maturity securities-available-for-sale, Percentage	0.90%
Amount of Commercial Mortgage Loans Granted Forbearance	5.2	40.1
Amount of funding agreements from the Federal Home Loan Bank (FHLB).	139
Amount of the collateral pledged in support of federal home loan bank funding agreements outstanding.	174.4
Corporate Bond Securities [Member]
Schedule of Investments [Line Items]
Total fixed maturity securities-available-for-sale	$7,272.60	$6,545.70

Investments_Amortized_Costs_An

Investments (Amortized Costs And Fair Values Of Fixed Maturity Securities Available-For-Sale) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Investments [Line Items]
Total fixed maturity securities-available-for-sale, Amortized Cost	$7,390	$6,811.90
Total fixed maturity securities-available-for-sale, Unrealized Gains	423.1	385.8
Total fixed maturity securities-available-for-sale, Unrealized Losses	-39.4	-77.2
Total fixed maturity securities-available-for-sale	7,773.70	7,120.50
Estimate Of Fair Value Fair Value Disclosure [Member]
Schedule of Investments [Line Items]
Total fixed maturity securities-available-for-sale	7,773.70	7,120.50
U S Government Agencies Debt Securities [Member]
Schedule of Investments [Line Items]
Total fixed maturity securities-available-for-sale, Amortized Cost	262	320.8
Total fixed maturity securities-available-for-sale, Unrealized Gains	38.3	32.8
Total fixed maturity securities-available-for-sale, Unrealized Losses	-0.2	-0.4
Total fixed maturity securities-available-for-sale	300.1	353.2
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	300.1	353.2
U S States And Political Subdivisions [Member]
Schedule of Investments [Line Items]
Total fixed maturity securities-available-for-sale, Amortized Cost	125.8	134.3
Total fixed maturity securities-available-for-sale, Unrealized Gains	10.4	6.8
Total fixed maturity securities-available-for-sale, Unrealized Losses	-0.1	-0.8
Total fixed maturity securities-available-for-sale	136.1	140.3
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	136.1	140.3
Foreign Government Debt [Member]
Schedule of Investments [Line Items]
Total fixed maturity securities-available-for-sale, Amortized Cost	58.4	58.9
Total fixed maturity securities-available-for-sale, Unrealized Gains	6.5	6.6
Total fixed maturity securities-available-for-sale, Unrealized Losses	0	0
Total fixed maturity securities-available-for-sale	64.9	65.5
Foreign Government Debt [Member] \| Estimate Of Fair Value Fair Value Disclosure [Member]
Schedule of Investments [Line Items]
Total fixed maturity securities-available-for-sale	64.9	65.5
Corporate Bond Securities [Member]
Schedule of Investments [Line Items]
Total fixed maturity securities-available-for-sale, Amortized Cost	6,943.80	6,282.10
Total fixed maturity securities-available-for-sale, Unrealized Gains	367.9	339.6
Total fixed maturity securities-available-for-sale, Unrealized Losses	-39.1	-76
Total fixed maturity securities-available-for-sale	7,272.60	6,545.70
Corporate Bond Securities [Member] \| Estimate Of Fair Value Fair Value Disclosure [Member]
Schedule of Investments [Line Items]
Total fixed maturity securities-available-for-sale	7,272.60	6,545.70
S And P Five Hundred Index Options [Member]
Schedule of Investments [Line Items]
Total fixed maturity securities-available-for-sale, Amortized Cost		15.8
Total fixed maturity securities-available-for-sale, Unrealized Gains		0
Total fixed maturity securities-available-for-sale, Unrealized Losses		0
Total fixed maturity securities-available-for-sale		15.8
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		$15.80

Investments_Schedule_Of_Contra

Investments (Schedule Of Contractual Maturities Of Fixed Maturity Securities Available-For-Sale) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Investments [Abstract]
Due in one year or less, Amortized cost	$649	$486.20
Due after one year through five years, Amortized cost	3,060.80	2,974.50
Due after five years through ten years, Amortized Cost	2,847.90	2,497.50
Due after ten years, Amortized Cost	832.3	853.7
Total fixed maturity securities-available-for-sale, Amortized Cost	7,390	6,811.90
Due in one year or less, Fair Value	658	495.1
Due after one year through five years, Fair Value	3,215.40	3,168.90
Due after five years through ten years, Fair Value	2,916.70	2,524.60
Due after ten years, Fair Value	983.6	931.9
Total fixed maturity securities-available-for-sale	$7,773.70	$7,120.50

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, 2014		Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	$5,321.10		$5,405.10
Commercial mortgage loans, Percentage	100.00%		100.00%
California [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	1,434.20		1,455.50
Commercial mortgage loans, Percentage	27.00%		26.90%
Texas [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	623.4		618.8
Commercial mortgage loans, Percentage	11.70%		11.50%
Florida [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	309.4		331.6
Commercial mortgage loans, Percentage	5.80%		6.10%
Georgia [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	306.6		310.7
Commercial mortgage loans, Percentage	5.80%		5.80%
Other States [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	2,647.50		2,688.50
Commercial mortgage loans, Percentage	49.70%		49.70%
Pacific [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	1,914.60	[1]	1,910.10	[1]
Commercial mortgage loans, Percentage	36.00%	[1]	35.30%	[1]
South Atlantic [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	1,065.50	[1]	1,090	[1]
Commercial mortgage loans, Percentage	20.00%	[1]	20.20%	[1]
West South Central [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	676.9	[1]	672.8	[1]
Commercial mortgage loans, Percentage	12.70%	[1]	12.40%	[1]
Mountain [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	606.5	[1]	611.4	[1]
Commercial mortgage loans, Percentage	11.40%	[1]	11.30%	[1]
East North Central [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	466	[1]	473.8	[1]
Commercial mortgage loans, Percentage	8.80%	[1]	8.80%	[1]
Middle Atlantic [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	215.3	[1]	223	[1]
Commercial mortgage loans, Percentage	4.00%	[1]	4.10%	[1]
West North Central [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	140.1	[1]	186.9	[1]
Commercial mortgage loans, Percentage	2.60%	[1]	3.50%	[1]
East South Central [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	188.7		166.6	[1]
Commercial mortgage loans, Percentage	3.60%	[1]	3.10%	[1]
New England [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	47.5	[1]	70.5	[1]
Commercial mortgage loans, Percentage	0.90%	[1]	1.30%	[1]
Retail [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	2,627.10		2,629.20
Commercial mortgage loans, Percentage	49.40%		48.60%
Office [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	1,013.40		982.4
Commercial mortgage loans, Percentage	19.10%		18.20%
Industrial [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	1,001.50		1,008.70
Commercial mortgage loans, Percentage	18.80%		18.70%
Hotels And Motels [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	165.7		276.3
Commercial mortgage loans, Percentage	3.10%		5.10%
Commercial [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	213.6		218.6
Commercial mortgage loans, Percentage	4.00%		4.00%
Apartment And Other [Member]
Commercial Mortgage Loans [Line Items]
Commercial mortgage loans, net	$299.80		$289.90
Commercial mortgage loans, Percentage	5.60%		5.40%

[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, 2014	Dec. 31, 2013
Investments [Abstract]
Beginning balance	$43.60	$46.60
Provision	7.1	15.9
Charge-offs, net	-10.7	-18.9
Ending balance	40	43.6
Related Allowance	23.8	25.9
General loan loss allowance	16.2	17.7
Commercial mortgage loan loss allowance	$40	$43.60

Investments_Schedule_Of_Record

Investments (Schedule Of Recorded Investment In Commercial Mortgage Loans) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments [Abstract]
Commercial mortgage loans collectively evaluated for impairment	$5,255.20	$5,334.40
Commercial mortgage loans individually evaluated for impairment	105.9	114.3
Commercial mortgage loan loss allowance	-40	-43.6	-46.6
Total commercial mortgage loans	$5,321.10	$5,405.10

Investments_Performing_And_Non

Investments (Performing And Nonperforming Commercial Mortgage Loans By Property Type) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	$5,321.10	$5,405.10
Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	5,314.90	5,393.20
Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	6.2	11.9
Retail [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	2,627.10	2,629.20
Retail [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	2,622.40	2,624.20
Retail [Member] \| Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	4.7	5
Office [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	1,013.40	982.4
Office [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	1,012.70	979.6
Office [Member] \| Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	0.7	2.8
Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	1,001.50	1,008.70
Industrial [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	1,001.40	1,004.60
Industrial [Member] \| Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	0.1	4.1
Hotels And Motels [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	165.7	276.3
Hotels And Motels [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	165.7	276.3
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	213.6	218.6
Commercial [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	213.6	218.6
Commercial [Member] \| Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	0	0
Apartment And Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	299.8	289.9
Apartment And Other [Member] \| Performing Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	299.1	289.9
Apartment And Other [Member] \| Nonperforming Financing Receivable [Member]
Financing Receivable, Recorded Investment [Line Items]
Commercial mortgage loans, net	$0.70	$0

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, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Impaired recorded investment, with no related allowance	$31.70	$26.60
Impaired recorded investment, with related allowance	74.2	87.7
Total impaired recorded investment	105.9	114.3
Impaired unpaid principal balance, with no related allowance	31.7	26.6
Impaired unpaid principal balance, with related allowance	74.2	87.7
Total impaired unpaid principal balance	105.9	114.3
Related Allowance	23.8	25.9
Impaired recorded investment with no related allowance on nonaccrual status	11	9.1
Impaired recorded investment with related allowance on nonaccrual status	8.4	26.4
Total impaired recorded investment amount on Nonaccrual Status	19.4	35.5
Retail [Member]
Financing Receivable, Impaired [Line Items]
Impaired recorded investment, with no related allowance	25	16.1
Impaired recorded investment, with related allowance	52.2	58.5
Impaired unpaid principal balance, with no related allowance	25	16.1
Impaired unpaid principal balance, with related allowance	52.2	58.5
Related Allowance	12.3	16.1
Impaired recorded investment with no related allowance on nonaccrual status	10.5	7.6
Impaired recorded investment with related allowance on nonaccrual status	7.7	21.6
Office [Member]
Financing Receivable, Impaired [Line Items]
Impaired recorded investment, with no related allowance	1.6	3.9
Impaired recorded investment, with related allowance	8.6	9.7
Impaired unpaid principal balance, with no related allowance	1.6	3.9
Impaired unpaid principal balance, with related allowance	8.6	9.7
Related Allowance	2.9	3.8
Impaired recorded investment with no related allowance on nonaccrual status	0	1.5
Impaired recorded investment with related allowance on nonaccrual status	0	0.9
Industrial [Member]
Financing Receivable, Impaired [Line Items]
Impaired recorded investment, with no related allowance	0	1
Impaired recorded investment, with related allowance	4.6	12.6
Impaired unpaid principal balance, with no related allowance	0	1
Impaired unpaid principal balance, with related allowance	4.6	12.6
Related Allowance	1.6	2.4
Impaired recorded investment with no related allowance on nonaccrual status	0	0
Impaired recorded investment with related allowance on nonaccrual status	0.1	1.4
Commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired recorded investment, with no related allowance	2.3	1.8
Impaired recorded investment, with related allowance	8.5	6
Impaired unpaid principal balance, with no related allowance	2.3	1.8
Impaired unpaid principal balance, with related allowance	8.5	6
Related Allowance	7	3.6
Impaired recorded investment with no related allowance on nonaccrual status	0.5	0
Impaired recorded investment with related allowance on nonaccrual status	0.6	2.5
Apartment And Other [Member]
Financing Receivable, Impaired [Line Items]
Impaired recorded investment, with no related allowance	2.8	3.8
Impaired recorded investment, with related allowance	0.3	0.9
Impaired unpaid principal balance, with no related allowance	2.8	3.8
Impaired unpaid principal balance, with related allowance	0.3	0.9
Related Allowance	0	0
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, 2014	Dec. 31, 2013
	NumberOfLoans	NumberOfLoans
Financing Receivable, Modifications [Line Items]
Number of Loans	54	22
Pre - Restructuring Recorded Investment	$50.20	$24.70
Post - Restructuring Recorded Investment	48.7	25.6
Retail [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	45	16
Pre - Restructuring Recorded Investment	42.7	20
Post - Restructuring Recorded Investment	40.9	20.8
Office [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	3	3
Pre - Restructuring Recorded Investment	1.4	1.6
Post - Restructuring Recorded Investment	1.2	1.6
Industrial [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	4	2
Pre - Restructuring Recorded Investment	3.1	2.2
Post - Restructuring Recorded Investment	3.4	2.3
Hotels And Motels [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0
Pre - Restructuring Recorded Investment	0
Post - Restructuring Recorded Investment	0
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	2	1
Pre - Restructuring Recorded Investment	3	0.9
Post - Restructuring Recorded Investment	3.2	0.9
Apartment And Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans	0
Pre - Restructuring Recorded Investment	0
Post - Restructuring Recorded Investment	$0

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Investments [Abstract]
Average recorded investment	$105.60	$113.40	$101.30

Investments_Aging_Of_Commercia

Investments (Aging Of Commercial Mortgage Loans By Property Type) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 Days Past Due	$2.80	$10.40
60 Days Past Due	2.7	3.6
Greater Than 90 Days Past Due	5.9	11.6
Financing Receivable, Recorded Investment, Past Due, Total	11.4	25.6
Allowance Related to Past Due	-2.3	-3.3
Current	5,312	5,382.80
Total commercial mortgage loans	5,321.10	5,405.10
Retail [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 Days Past Due	0.2	2.8
60 Days Past Due	2	0.3
Greater Than 90 Days Past Due	4.8	6.1
Financing Receivable, Recorded Investment, Past Due, Total	7	9.2
Allowance Related to Past Due	-2.1	-1.5
Current	2,622.20	2,621.50
Total commercial mortgage loans	2,627.10	2,629.20
Office [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 Days Past Due	1.9	1.3
60 Days Past Due	0	0
Greater Than 90 Days Past Due	0.8	3.7
Financing Receivable, Recorded Investment, Past Due, Total	2.7	5
Allowance Related to Past Due	0	-0.9
Current	1,010.70	978.3
Total commercial mortgage loans	1,013.40	982.4
Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 Days Past Due	0.5	0
60 Days Past Due	0	3.3
Greater Than 90 Days Past Due	0.3	1.8
Financing Receivable, Recorded Investment, Past Due, Total	0.8	5.1
Allowance Related to Past Due	-0.2	-0.9
Current	1,000.90	1,004.50
Total commercial mortgage loans	1,001.50	1,008.70
Hotels And Motels [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 Days Past Due	0	6.3
60 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Financing Receivable, Recorded Investment, Past Due, Total	0	6.3
Allowance Related to Past Due	0	0
Current	165.7	270
Total commercial mortgage loans	165.7	276.3
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 Days Past Due	0	0
60 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Financing Receivable, Recorded Investment, Past Due, Total	0	0
Allowance Related to Past Due	0	0
Current	213.6	218.6
Total commercial mortgage loans	213.6	218.6
Apartment And Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 Days Past Due	0.2	0
60 Days Past Due	0.7	0
Greater Than 90 Days Past Due	0	0
Financing Receivable, Recorded Investment, Past Due, Total	0.9	0
Allowance Related to Past Due	0	0
Current	298.9	289.9
Total commercial mortgage loans	$299.80	$289.90

Investments_Schedule_Of_Gross_

Investments (Schedule Of Gross Unrealized Losses And Fair Value Of Investments) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	number	number
Schedule of Investments [Line Items]
Unrealized losses, Number	1,004	927
Unrealized losses, Amount	$39.40	$77.20
Unrealized losses, Less than 12 months, Number	683	867
Unrealized losses, Less than 12 months, Amount	21.3	67.5
Unrealized losses, 12 or more months, Number	321	60
Unrealized losses, 12 or more months, Amount	18.1	9.7
Fair market value of securities with unrealized losses, Number	1,004	927
Fair market value of securities with unrealized losses, Amount	1,776.50	1,696.10
Fair market value of securities with unrealized losses, Less than 12 months, Number	683	867
Fair market value of securities with unrealized losses, Less than 12 months, Amount	1,162.20	1,590
Fair market value of securities with unrealized losses, 12 or more months, Number	321	60
Fair market value of securities with unrealized losses, 12 or more months, Amount	614.3	106.1
U S States And Political Subdivisions [Member]
Schedule of Investments [Line Items]
Unrealized losses, Number	4	10
Unrealized losses, Amount	0.1	0.8
Unrealized losses, Less than 12 months, Number	0	10
Unrealized losses, Less than 12 months, Amount	0	0.8
Unrealized losses, 12 or more months, Number	4	0
Unrealized losses, 12 or more months, Amount	0.1	0
Fair market value of securities with unrealized losses, Number	4	10
Fair market value of securities with unrealized losses, Amount	6.9	15.4
Fair market value of securities with unrealized losses, Less than 12 months, Number	0	10
Fair market value of securities with unrealized losses, Less than 12 months, Amount	0	15.4
Fair market value of securities with unrealized losses, 12 or more months, Number	4	0
Fair market value of securities with unrealized losses, 12 or more months, Amount	6.9	0
Corporate Bond Securities [Member]
Schedule of Investments [Line Items]
Unrealized losses, Number	995	908
Unrealized losses, Amount	39.1	76
Unrealized losses, Less than 12 months, Number	683	848
Unrealized losses, Less than 12 months, Amount	21.3	66.3
Unrealized losses, 12 or more months, Number	312	60
Unrealized losses, 12 or more months, Amount	17.8	9.7
Fair market value of securities with unrealized losses, Number	995	908
Fair market value of securities with unrealized losses, Amount	1,763.20	1,663.80
Fair market value of securities with unrealized losses, Less than 12 months, Number	683	848
Fair market value of securities with unrealized losses, Less than 12 months, Amount	1,162.20	1,557.70
Fair market value of securities with unrealized losses, 12 or more months, Number	312	60
Fair market value of securities with unrealized losses, 12 or more months, Amount	601	106.1
U S Government Agencies Debt Securities [Member]
Schedule of Investments [Line Items]
Unrealized losses, Number	5	9
Unrealized losses, Amount	0.2	0.4
Unrealized losses, Less than 12 months, Number	0	9
Unrealized losses, Less than 12 months, Amount	0	0.4
Unrealized losses, 12 or more months, Number	5	0
Unrealized losses, 12 or more months, Amount	0.2	0
Fair market value of securities with unrealized losses, Number	5	9
Fair market value of securities with unrealized losses, Amount	6.4	16.9
Fair market value of securities with unrealized losses, Less than 12 months, Number	0	9
Fair market value of securities with unrealized losses, Less than 12 months, Amount	0	16.9
Fair market value of securities with unrealized losses, 12 or more months, Number	5	0
Fair market value of securities with unrealized losses, 12 or more months, Amount	$6.40	$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, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary Of Investment Income [Line Items]
Investment income									$642.70	$666.70	$664.10
Investment expenses									-22.4	-22.9	-22.3
Tax-advantaged investment operating losses									-19.4	-13.9	-13.3
Net investment income	153.4	147.1	149.8	150.6	160.8	155.8	154.1	159.2	600.9	629.9	628.5
Total Fixed Maturity Securities [Member]
Summary Of Investment Income [Line Items]
Investment income									296.4	303	316.8
S And P Five Hundred Index Options [Member]
Summary Of Investment Income [Line Items]
Investment income									8.6	14.4	7.8
Commercial Mortgage Loans [Member]
Summary Of Investment Income [Line Items]
Investment income									332.1	341.7	331.9
Total Real Estate [Member]
Summary Of Investment Income [Line Items]
Investment income									1.1	-1.4	-1
Other Investment Classification [Member]
Summary Of Investment Income [Line Items]
Investment income									$4.50	$9	$8.60

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, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Gross Capital Gains And Losses By Investment Type [Line Items]
Gross capital gains									$10.30	$15.40	$14.20
Gross capital losses									-24.3	-31.1	-22.9
Total net capital losses	-7.2	-5.2	-0.5	-1.1	-2.8	-8.7	-2.6	-1.6	-14	-15.7	-8.7
Total Fixed Maturity Securities [Member]
Gross Capital Gains And Losses By Investment Type [Line Items]
Gross capital gains									5.9	9.8	10.8
Gross capital losses									-2.8	-2.3	-5
Total Real Estate [Member]
Gross Capital Gains And Losses By Investment Type [Line Items]
Gross capital gains									2	3	1.3
Gross capital losses									-6.4	-9.6	-3.5
Commercial Mortgage Loans [Member]
Gross Capital Gains And Losses By Investment Type [Line Items]
Gross capital gains									2.4	2.4	1.5
Gross capital losses									-7.1	-15.9	-13.4
Other Investment Classification [Member]
Gross Capital Gains And Losses By Investment Type [Line Items]
Gross capital gains									0	0.2	0.6
Gross capital losses									($8)	($3.30)	($1)

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Impact On Interest Credited Changes In Actuarial Assumptions	($4)	($4.10)
S And P Five Hundred Index Options [Member]
Derivative [Line Items]
S&P 500 index options purchased per month	2
Expiry Date Of S And P Five Hundred Index Options Purchased Years	1 year 0 months 0 days
Derivative Option premiums paid	9.3	9.4
Amount received for derivative options exercised	20.1	19.3
Maximum credit exposure required increase in S&P 500 Index, percentage	4.50%
Interest Rate Swaps [Member]
Derivative [Line Items]
Collateral	$12.20

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Fair Value Of The Company's Derivative Assets And Liabilities) (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Derivative [Line Items]
Derivative Assets	$13.60
S And P Five Hundred Index Options [Member] \| Fixed Maturity Securities-Available-For-Sale [Member]
Derivative [Line Items]
Derivative Assets	13.6
S And P Five Hundred Index Options [Member] \| Fixed Maturity Securities-Available-For-Sale [Member] \| Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Assets			15.8
DerivativeNotionalAmount	418.2		350.5
Index Based Interest Guarantees [Member] \| Other Policyholder Funds [Member] \| Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Liabilities	77		67.6
DerivativeNotionalAmount	0	[1]	0	[1]
Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative Positions	-4.7		0
Interest Rate Swaps [Member] \| Other Liabilities [Member] \| Designated As Hedging Instrument[Member]
Derivative [Line Items]
Derivative Liabilities	4.7
DerivativeNotionalAmount	$350

[1]	(1)The underlying factors for index-based guarantees vary by contract and other criteria, such as floors and ceilings on rates and future payouts.
[1]

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, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
All other net capital losses									($12.80)	($14.60)	($5.50)
Net investment income	153.4	147.1	149.8	150.6	160.8	155.8	154.1	159.2	600.9	629.9	628.5
Interest credited									164.6	176.4	171.3
Net (loss) gain									-3.3	5.4	1.4
Interest Rate Swaps [Member] \| Designated As Hedging Instrument[Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net (loss) gain									-4.7
S And P Five Hundred Index Options [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net investment income									8.6	14.4	7.8
Index Based Interest Guarantees [Member] \| Not Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest credited									($7.20)	($9)	($6.40)

Derivative_Financial_Instrumen5

Derivative Financial Instruments (Fair Value Of Derivative Assets And Its Maximum Credit Risk Exposure) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified	Dec. 31, 2014
Derivative [Line Items]
Derivative Assets at Fair Value	$13.60
Maximum Credit Risk	19.1
Merrill Lynch International [Member]
Derivative [Line Items]
Derivative Assets at Fair Value	5.6
Maximum Credit Risk	9.3
Bank Of New York Mellon [Member]
Derivative [Line Items]
Derivative Assets at Fair Value	4.5
Maximum Credit Risk	5.4
Goldman Sachs [Member]
Derivative [Line Items]
Derivative Assets at Fair Value	3.5
Maximum Credit Risk	$4.40

Derivative_Balance_Sheet_Offse

Derivative Balance Sheet Offsetting (Details) (Interest Rate Swaps [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Interest Rate Swaps [Member]
Offsetting Liabilities [Line Items]
Derivative Fair Value Of Derivative Liability	($5.10)	$0
Derivative Fair Value Of Derivative Asset	0.4	0
Net interest rate swaps	-4.7	0
Accrued interest payable	-2.2	0
Collateral	12.2	0
Net Amount	$5.30	$0

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Value Of Business Acquired [Member]
Indefinite-lived Intangible Assets by Major Class [Line Items]
Intangible assets, accumulated amortization	$71	$68.70
Intangible asset impairment writedown	0	1	0.8
Other Intangible Assets [Member]
Indefinite-lived Intangible Assets by Major Class [Line Items]
Intangible assets, accumulated amortization	$48.40	$42.60

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Finite Lived Intangible Assets [Line Items]
Carrying value at beginning of period, DAC	$319.10	$284.90	$274.40
Carrying value at beginning of period, VOBA	20.1	23.4	26.4
Carrying value at beginning of period, Other intangible assets	32.1	38.2	44.1
Total balance at beginning of period	371.3	346.5	344.9
Deferred or acquired, DAC	80.1	76.9	71.4
Total deferred or acquired	80.1	76.9	71.4
Amortization of DAC	-62.3	-42.7	-60.9
Amortized during period, VOBA	-2.3	-3.3	-3
Amortized during period, Other intangible assets	-5.8	-6.1	-5.9
Total amortized during period	-70.4	-52.1	-69.8
Carrying value at end of period, net DAC	336.9	319.1	284.9
Carrying value at end of period, net VOBA	17.8	20.1	23.4
Carrying value at end of period, net Other intangible assets	26.3	32.1	38.2
Total carrying value at end of period	$381	$371.30	$346.50

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, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred Acquisition Costs Value Of Business Acquired And Other Intangible Assets Disclosures [Abstract]
DAC	$82.40	$80.10
VOBA	$3.70	$4.30
DAC, percent	24.50%	25.10%
VOBA, percent	20.80%	21.40%

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Deferred Acquisition Costs Value Of Business Acquired And Other Intangible Assets Disclosures [Abstract]
Decrease to DAC and VOBA	($3.20)	($1.70)	($1.70)

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, 2014
Deferred Acquisition Costs Value Of Business Acquired And Other Intangible Assets Disclosures [Abstract]
2015	$7.60
2016	6.1
2017	4.6
2018	4.3
2019	$4.10

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, 2014	Dec. 31, 2013	Dec. 31, 2012
Plus: reinsurance recoverable	$994.20	$988.10
Balance at end of the year, gross of reinsurance	4,021.70	4,021.90	4,005.90
Disability Insurance [Member]
Balance at beginning of the year, gross of reinsurance	4,021.90	4,005.90	3,857
Less: reinsurance recoverable	-139.9	-128.6	-117.3
Net balance at beginning of the year	3,882	3,877.30	3,739.70
Incurred related to Current year	1,033.10	1,081.70	1,140.30
Incurred related to Prior year's interest	172.3	180.3	181.2
LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseIncurredClaimsPriorYears	-117.4	-133.2	-79.8
Total incurred	1,088	1,128.80	1,241.70
Paid related to Current year	-322.2	-345.9	-354.8
Paid related to Prior year	-780.9	-778.2	-749.3
Total paid	-1,103.10	-1,124.10	-1,104.10
Net balance at end of the year	3,866.90	3,882	3,877.30
Plus: reinsurance recoverable	154.8	139.9	128.6
Balance at end of the year, gross of reinsurance	$4,021.70	$4,021.90	$4,005.90

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, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Liability For Unpaid Claims, Claim Adjustment Expenses And Other Policyholder Funds [Abstract]
Future policy benefits and claims	$5,832.30	$5,846.90	$5,843.20
Liability for Future Policy Benefits, Life	-727.7	-751.7	-765.3
Liability For Future Policy Benefits Individual Life	-596.3	-603.6	-600.9
Liability for Future Policy Benefits, Individual and Group Annuities and Supplementary Contracts	-219.9	-220	-237.4
Liability for Future Policy Benefits, Disability and Accident Benefits	-266.7	-249.7	-233.7
Liability for unpaid claims and claims adjustment expenses	$4,021.70	$4,021.90	$4,005.90

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, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other Policyholder Funds [Line Items]
Other policyholder funds	$6,537.80	$6,051.60
Employer Sponsored Defined Contribution And Benefit Plans Funds [Member]
Other Policyholder Funds [Line Items]
Other policyholder funds	2,104.40	1,954.10
Individual Fixed Rate Annuity Funds [Member]
Other Policyholder Funds [Line Items]
Other policyholder funds	2,383.60	2,541.70
Indexed Annuity Funds [Member]
Other Policyholder Funds [Line Items]
Other policyholder funds	504	440.8
Investment Only Stable Asset Funds [Member]
Other Policyholder Funds [Line Items]
Other policyholder funds	610.9	326.1
Other Policyholder Funds [Member]
Other Policyholder Funds [Line Items]
Other policyholder funds	$934.90	$788.90

Reinsurance_Narrative_Details

Reinsurance (Narrative) (Details) (USD $)	12 Months Ended
Reinsurance (Narrative) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplementary Insurance Information, by Segment [Line Items]
Premiums assumed percentage to total company's premiums	4.50%	4.60%	4.50%
Recoveries recognized under reinsurance agreements	$92,800,000	$79,800,000	$74,000,000
Amounts recoverable from reinsurers	994,200,000	988,100,000
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	241,100,000
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	781,400,000	791,000,000
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	484,700,000
Catastrophe reinsurance pool, number of participants	18
Catastrophe reinsurance pool annual membership fee	30,000
Maximum potential loss for a single event catastrophe submitted by a single company	104,600,000
Maximum potential loss for a single event catastrophe submitted by multiple companies	261,500,000
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	$7,500

Reinsurance_Schedule_Of_Reinsu

Reinsurance (Schedule Of Reinsurance Information) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Premiums Net Life Insurance In Force [Abstract]
Gross amount - life insurance in force	$306,566				$321,881.70				$306,566	$321,881.70	$346,814.50
Ceded premiums - life insurance in force	6,239.80				5,966.80				6,239.80	5,966.80	7,233.10
Assumed Premiums - life insurance in force	51.5				57.7				51.5	57.7	65.1
Net amount - life insurance in force	300,377.70				315,972.60				300,377.70	315,972.60	339,646.50
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount									2,086.10	2,157.10	2,201.20
Ceded to Other Companies									126.5	129.5	134.7
Assumed From Other Companies									92.8	96.7	97.4
Net Amount	515.8	507.3	519.2	510.1	528.6	524.4	535.1	536.2	2,052.40	2,124.30	2,163.90
Percentage of Amount Assumed to Net									4.50%	4.60%	4.50%
Life Insurance Segment [Member]
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Gross Amount									854.6	898.5	937.9
Ceded to Other Companies									46.3	48.5	51
Assumed From Other Companies									0	0	0
Net Amount									808.3	850	886.9
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									1,231.50	1,258.60	1,263.30
Ceded to Other Companies									80.2	81	83.7
Assumed From Other Companies									92.8	96.7	97.4
Net Amount									$1,244.10	$1,274.30	$1,277
Percentage of Amount Assumed to Net									7.50%	7.60%	7.60%

Reinsurance_Of_Blocks_Of_Busin1

Reinsurance Of Blocks Of Business (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
	NumberOfGroupInsuranceContracts
	NumberOfInsuredIndividuals
Ceded Credit Risk [Line Items]
VOBA recorded	$17.80	$20.10	$23.40	$26.40
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	190.1
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	562.3
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, 2014		Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Insurance Information [Line Items]
DAC	$336.90					$319.10					$336.90		$319.10		$284.90		$274.40
Future Policy Benefits And Claims	5,832.30					5,846.90					5,832.30		5,846.90
Other Policyholder Funds	6,537.80					6,051.60					6,537.80		6,051.60
Premiums Revenues	515.8		507.3	519.2	510.1	528.6		524.4	535.1	536.2	2,052.40		2,124.30		2,163.90
Net Investment Income	153.4		147.1	149.8	150.6	160.8		155.8	154.1	159.2	600.9		629.9		628.5
Amortization of DAC											62.3		42.7		60.9
Insurance Products [Member]
Insurance Information [Line Items]
DAC	336.9	[1]				319.1	[1]				336.9	[1]	319.1	[1]	284.9	[1]
Future Policy Benefits And Claims	5,832.30					5,846.90					5,832.30		5,846.90		5,843.20
Other Policyholder Funds	6,537.80					6,051.60					6,537.80		6,051.60		5,531.10
Premiums Revenues											2,052.40		2,124.30		2,163.90
Net Investment Income											582.8		613.8		618.3
Benefits, Claims and Interest Credited											1,746.80		1,831.80		1,964.30
Amortization of DAC											67.3		62.9		61.6
Other Operating Expenses											705.9	[2]	694.8	[2]	706.8	[2]
Insurance Services [Member]
Insurance Information [Line Items]
Premiums Revenues											2,041.90		2,117.40		2,157.20
Net Investment Income											299.5		320.6		339.7
Insurance Services [Member] \| Insurance Products [Member]
Insurance Information [Line Items]
DAC	254.5	[1]				239	[1]				254.5	[1]	239	[1]	223.9	[1]
Future Policy Benefits And Claims	5,612.40					5,627					5,612.40		5,627		5,605.80
Other Policyholder Funds	499.7					514.2					499.7		514.2		557
Premiums Revenues											2,041.90		2,117.40		2,157.20
Net Investment Income											299.5		320.6		339.7
Benefits, Claims and Interest Credited											1,564		1,642		1,777.50
Amortization of DAC											45.9		45.2		45.8
Other Operating Expenses											539.4	[2]	538.9	[2]	553.5	[2]
Employee Benefits [Member]
Insurance Information [Line Items]
Premiums Revenues											1,842.80		1,926.90		1,980.60
Net Investment Income											247.4		267.8		286
Employee Benefits [Member] \| Insurance Products [Member]
Insurance Information [Line Items]
DAC	25.7	[1]				24.2	[1]				25.7	[1]	24.2	[1]	24.6	[1]
Future Policy Benefits And Claims	3,936.90					3,995.90					3,936.90		3,995.90		4,025.60
Other Policyholder Funds	302.8					315.3					302.8		315.3		353.5
Premiums Revenues											1,842.80		1,926.90		1,980.60
Net Investment Income											247.4		267.8		286
Benefits, Claims and Interest Credited											1,434		1,520.20		1,661.30
Amortization of DAC											21.9		22.6		23.9
Other Operating Expenses											470.9	[2]	473.2	[2]	489.2	[2]
Individual Disability [Member]
Insurance Information [Line Items]
Premiums Revenues											199.1		190.5		176.6
Net Investment Income											52.1		52.8		53.7
Individual Disability [Member] \| Insurance Products [Member]
Insurance Information [Line Items]
DAC	228.8	[1]				214.8	[1]				228.8	[1]	214.8	[1]	199.3	[1]
Future Policy Benefits And Claims	1,675.50					1,631.10					1,675.50		1,631.10		1,580.20
Other Policyholder Funds	196.9					198.9					196.9		198.9		203.5
Premiums Revenues											199.1		190.5		176.6
Net Investment Income											52.1		52.8		53.7
Benefits, Claims and Interest Credited											130		121.8		116.2
Amortization of DAC											24		22.6		21.9
Other Operating Expenses											68.5	[2]	65.7	[2]	64.3	[2]
Asset Management Segment [Member]
Insurance Information [Line Items]
Premiums Revenues											10.5		6.9		6.7
Net Investment Income											283.3		293.2		278.6
Asset Management Segment [Member] \| Insurance Products [Member]
Insurance Information [Line Items]
DAC	82.4	[1]				80.1	[1]				82.4	[1]	80.1	[1]	61	[1]
Future Policy Benefits And Claims	219.9					219.9					219.9		219.9		237.4
Other Policyholder Funds	6,038.10					5,537.40					6,038.10		5,537.40		4,974.10
Premiums Revenues											10.5		6.9		6.7
Net Investment Income											283.3		293.2		278.6
Benefits, Claims and Interest Credited											182.8		189.8		186.8
Amortization of DAC											21.4		17.7		15.8
Other Operating Expenses											$166.50	[2]	$155.90	[2]	$153.30	[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, 2014	Dec. 31, 2013	Dec. 31, 2012
Insurance Information [Line Items]
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	$1,228.40	$1,359
Company Action Level RBC [Member]
Insurance Information [Line Items]
Percentage of company's capital and surplus of required capital and surplus	445.00%	398.00%
Authorized Control Level RBC [Member]
Insurance Information [Line Items]
Required statutory capital and surplus	149.6	186.6
Percentage of company's capital and surplus of required capital and surplus	890.00%	796.00%
Parent Company [Member]
Insurance Information [Line Items]
Capital contributions to subsidiaries	240.3	0.7	14.5
Standard Insurance Company [Member]
Insurance Information [Line Items]
Dividends which can be declared without additional statutory approval	208.5	195.1
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	1,150	1,290
Dividends from Insurance subidiaries to Parent Company	390	130
Capital contributions to subsidiaries	240
Standard Life Insurance Company Of New York [Member]
Insurance Information [Line Items]
Capital contributions to subsidiaries	$0	$0

Regulatory_Matters_Reconciliat

Regulatory Matters (Reconciliation Of The Statutory Capital And Surplus Of The Insurance) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Statutory capital and surplus	$1,228.40	$1,359
GAAP equity	2,171.80	2,152.80	2,169	1,990.40
Future Policy Benefits And Other Policyholder Funds [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP equity:	276	325.8
Dac Voba And Other Intangible Assets [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP equity:	365.7	351.6
Deferred Tax Liabilities [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP equity:	-245.6	-265.3
Asset Valuation Reserve [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP equity:	106.2	127.5
Valuation Of Investments [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP equity:	259.6	236.4
Interest Maintenance Reserve [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP equity:	28.5	25.5
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:	277.5	116.1
Non Admitted Assets [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP equity:	166.3	178.2
Pension and postretirement benefit plans [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP equity:	-11.3	-6.6
Capital Lease Obligations [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP equity:	-2.1	-3.4
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:	($27.40)	($42)

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, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Statutory gain from operations									$213.40	$198.50	$131.50
GAAP net income	56.2	71.1	41.9	50.1	65	59	57.7	46.8	219.3	228.5	138.5
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:									-24.3	11	26.4
Dac And Voba Net Of Amortization [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP net income:									9.2	9.4	5.5
Deferred Income Taxes [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP net income:									-5.7	-13.5	-22.4
Current Income Taxes [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP net income:									9.6	9.6	17.2
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	-8.9	-23.8
Deferred Capital Gains Interest Maintenance Reserve [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP net income:									3	0.7	5
Other Net [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP net income:									-0.1	-0.8	0.4
Pension And Postretirement Benefit Plans [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP net income:									-2.6	17.6	-1.7
Share Based Compnesation Statutory Reconciliation [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP net income:									0	-3.6	-5.4
Investments Statutory Reconciliation [Member]
Statutory Accounting Practices Statutory To Gaap Reconciling Items [Line Items]
Adjustments to reconcile to GAAP net income:									$7.90	$8.50	$5.80

LongTerm_Debt_Narrative_Detail

Long-Term Debt (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Debt instrument, face amount	$252.90
Debt instrument, interest rate, stated percentage	6.90%
Repayment of senior debt	47.1	0	250
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	252.9
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 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, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-term debt	$503.90	$551.90
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Long-term debt	252.9	300
Other Long Term Borrowings [Member]
Debt Instrument [Line Items]
Long-term debt	1	1.9
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, 2014	Dec. 31, 2013	Dec. 31, 2012
	NumberOfContractExtentions
	NumberOfDebtCovenants
Commitments And Contingencies [Line Items]
Line of creadit facility initiation date	22-Jun-12
Line of Credit Facility, Current Borrowing Capacity	$250
Line of credit facility, maximum borrowing capacity	350
Line of credit facility, expiration date	22-Jun-18
Line Of Credit Facility Number Of One Year Extension Periods	0
Line of credit facility, financial covenants, number	2
Line of credit facility, amount outstanding	0
Total rent expense, operating lease commitments	13.3	13.7	15.2
Debt instrument, face amount	252.9
Debt instrument, interest rate, stated percentage	6.90%
Amount of funding agreements from the Federal Home Loan Bank (FHLB).	139
FHLB Fixed Interest Rate Maximum	3.79%
FHLB Fixed Interest Rate Minimum	0.38%
Commitments for Tax-advantaged investments	62.6
Loan Origination Commitments [Member]
Commitments And Contingencies [Line Items]
Total outstanding commitments to fund commercial mortgage loans	134.8
Maximum [Member]
Commitments And Contingencies [Line Items]
Fixed interest rate on commercial mortgage loan commitments	6.00%
FHLB Advances Years to Maturity	15 years
Minimum [Member]
Commitments And Contingencies [Line Items]
Fixed interest rate on commercial mortgage loan commitments	4.00%
FHLB Advances Years to Maturity	1 year
Junior Subordinated Debt [Member]
Commitments And Contingencies [Line Items]
Debt instrument, face amount	252.9
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, 2014
In Millions, unless otherwise specified	Dec. 31, 2014
Commitments And Contingencies [Abstract]
2015	$9.20
2016	8.8
2017	8.3
2018	3.9
2019	1.9
Thereafter	$1.30

Commitments_And_Contingencies_3

Commitments And Contingencies (Minimum Future Rental Receivables On Non-Cancelable Leases Of Retail And Office Space) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified	Dec. 31, 2014
Commitments And Contingencies [Abstract]
2015	$7.30
2016	5.3
2017	2.6
2018	2
2019	1.4
Thereafter	$4.90

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	$134.70		$309.30
Other Comprehensive Income Loss Before Reclassifications Net Of Tax	-20.1	[1]	-164.1	[2]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	-0.3	[3]	-10.5	[4]
Total other comprehensive income, net of tax	-20.4		-174.6		74.2
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	114.3		134.7		309.3
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	173.2		383
Other Comprehensive Income Loss Before Reclassifications Net Of Tax	50.3	[1]	-205.3	[2]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	-2	[3]	-4.5	[4]
Total other comprehensive income, net of tax	48.3		-209.8
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	221.5		173.2
Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	-38.5		-73.7
Other Comprehensive Income Loss Before Reclassifications Net Of Tax	-70.4	[1]	41.2	[2]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1.7	[3]	-6	[4]
Total other comprehensive income, net of tax	-68.7		35.2
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	($107.20)		($38.50)

[1]	Net of tax expense of $24.6 million for net unrealized gains on fixed maturity securities and net of tax benefit of $37.9 million for employee benefits.
[2]	Net of tax benefit of $111.1 million for net unrealized losses on fixed maturity securities and net of tax expense of $22.2 million for employee benefits.
[3]	Net of tax benefit of $1.1 million for net unrealized gains on fixed maturity securities and net of tax expense of $0.9 million for employee benefits.
[4]	Net of tax benefits of $3.1 million for net unrealized gains on fixed maturity securities and $3.2 million for employee benefits, respectively.

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income (Parenthenticals) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
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	$24.60	($111.10)
Reclassification from accumulated other comprehensive income current period tax	-1.1	-3.1
Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax effect on other comprehensive income (loss) before reclassifications	-37.9	22.2
Reclassification from accumulated other comprehensive income current period tax	$0.90	$3.20

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, 2014		Dec. 31, 2013
Severance, Lease Terminations, And Transition Costs [Line Items]
Beginning Accrued Liability	$0.20	[1]	$0.40	[1]
Charged to Expense, Net	-0.2		4.2
Expenditures	0		-4.4
Ending Accrued Liability	0		0.2	[1]
Employee Severance [Member]
Severance, Lease Terminations, And Transition Costs [Line Items]
Beginning Accrued Liability	0.2	[1]	0.1	[1]
Charged to Expense, Net	-0.2		2.9
Expenditures	0		-2.8
Ending Accrued Liability	0		0.2	[1]
Contract Termination [Member]
Severance, Lease Terminations, And Transition Costs [Line Items]
Beginning Accrued Liability	0	[1]	0.3	[1]
Charged to Expense, Net	0
Expenditures	0		-0.3
Ending Accrued Liability	0		0	[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	0		1.3
Expenditures	0		-1.3
Ending Accrued Liability	$0		$0	[1]

[1]	Amounts relate to restructuring charges implemented by the Company during 2011.

Subsequent_Events_NarrativeDet

Subsequent Events (Narrative)(Details) (Private client wealth management business, USD $)	Dec. 31, 2014
In Millions, unless otherwise specified	Dec. 31, 2014
Private client wealth management business
Segment Reporting Information [Line Items]
Assets Under Management Carrying Amount	$884.40
Percentage of Company's Total Assets Under Administration	3.30%

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, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information [Abstract]
Premiums	$515.80	$507.30	$519.20	$510.10	$528.60	$524.40	$535.10	$536.20	$2,052.40	$2,124.30	$2,163.90
Administrative fees	33.8	32.8	32.6	31.6	32	30.5	30.4	28.7	130.8	121.6	114.7
Net investment income	153.4	147.1	149.8	150.6	160.8	155.8	154.1	159.2	600.9	629.9	628.5
Net realized capital losses	-7.2	-5.2	-0.5	-1.1	-2.8	-8.7	-2.6	-1.6	-14	-15.7	-8.7
Total revenues	695.8	682	701.1	691.2	718.6	702	717	722.5	2,770.10	2,860.10	2,898.40
Benefits to policyholders	394.1	360.8	426.2	401.1	394.5	395	424.1	441.8	1,582.20	1,655.40	1,793
Net income	$56.20	$71.10	$41.90	$50.10	$65	$59	$57.70	$46.80	$219.30	$228.50	$138.50
Basic	$1.33	$1.66	$0.97	$1.14	$1.48	$1.33	$1.30	$1.05	$5.10	$5.16	$3.13
Diluted	$1.32	$1.65	$0.96	$1.13	$1.46	$1.32	$1.30	$1.05	$5.05	$5.13	$3.12