Principal Financial (PFG) 10-Q 29 Oct 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 22, 2014
Document and Entity Information	'	'
Entity Registrant Name	'PRINCIPAL FINANCIAL GROUP INC	'
Entity Central Index Key	'0001126328	'
Document Type	'10-Q	'
Document Period End Date	30-Sep-14	'
Amendment Flag	'false	'
Current Fiscal Year End Date	'--12-31	'
Entity Current Reporting Status	'Yes	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	293,667,067
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'

Consolidated_Statements_of_Fin

Consolidated Statements of Financial Position (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets	'	'
Fixed maturities, available-for-sale (2014 and 2013 include $287.2 million and $272.0 million related to consolidated variable interest entities)	$49,627.50	$48,757.10
Fixed maturities, trading (2014 and 2013 include $100.4 million and $110.4 million related to consolidated variable interest entities)	609.4	563.1
Equity securities, available-for-sale	124.8	110.5
Equity securities, trading (2014 and 2013 include $349.4 million and $327.2 million related to consolidated variable interest entities)	807.6	716.9
Mortgage loans	11,744.90	11,533.60
Real estate (2014 and 2013 include $276.2 million and $266.3 million related to consolidated variable interest entities)	1,352.10	1,271.60
Policy loans	837.7	859.7
Other investments (2014 and 2013 include $46.2 million and $68.1 million related to consolidated variable interest entities and $124.2 million and $142.9 million measured at fair value under the fair value option)	2,990.90	2,944.40
Total investments	68,094.90	66,756.90
Cash and cash equivalents	1,270.80	2,371.80
Accrued investment income	545.1	532.1
Premiums due and other receivables	1,189.30	1,241
Deferred acquisition costs	2,985.40	3,077
Property and equipment	590.1	500.7
Goodwill	1,034.40	1,100.30
Other intangibles	1,361.40	1,459
Separate account assets (2014 and 2013 include $35,079.9 million and $32,824.7 million related to consolidated variable interest entities)	138,296.70	130,018.40
Other assets	1,054.70	1,134.20
Total assets	216,422.80	208,191.40
Liabilities	'	'
Contractholder funds	34,680.80	35,958.30
Future policy benefits and claims	23,399.50	22,626.20
Other policyholder funds	811.9	758.9
Short-term debt	126.3	150.6
Long-term debt (2014 and 2013 include $74.9 million and $47.7 million related to consolidated variable interest entities)	2,529.20	2,601.40
Income taxes currently payable	18.1	5.2
Deferred income taxes	1,150.60	824
Separate account liabilities (2014 and 2013 include $35,079.9 million and $32,824.7 million related to consolidated variable interest entities)	138,296.70	130,018.40
Other liabilities (2014 and 2013 include $349.5 million and $362.4 million related to consolidated variable interest entities, of which $65.8 million and $104.9 million are measured at fair value under the fair value option)	4,984.60	5,224.20
Total liabilities	205,997.70	198,167.20
Redeemable noncontrolling interest	56.1	247.2
Stockholders' equity	'	'
Common stock, par value $.01 per share - 2,500.0 million shares authorized, 462.4 million and 459.3 million shares issued, and 293.6 million and 295.2 million shares outstanding in 2014 and 2013	4.6	4.6
Additional paid-in capital	9,916.90	9,798.90
Retained earnings (accumulated deficit)	5,945.20	5,405.40
Accumulated other comprehensive income (loss)	380.1	183.2
Treasury stock, at cost (168.8 million and 164.1 million shares in 2014 and 2013)	-5,930.50	-5,708
Total stockholders' equity attributable to Principal Financial Group, Inc.	10,316.40	9,684.20
Noncontrolling interest	52.6	92.8
Total stockholders' equity	10,369	9,777
Total liabilities and stockholders' equity	216,422.80	208,191.40
Series A	'	'
Stockholders' equity	'	'
Preferred stock, value	'	'
Total stockholders' equity	0	0
Series B	'	'
Stockholders' equity	'	'
Preferred stock, value	0.1	0.1
Total stockholders' equity	$0.10	$0.10

Consolidated_Statements_of_Fin1

Consolidated Statements of Financial Position (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, except Per Share data, unless otherwise specified
Fixed maturities, available-for-sale	$49,627.50	$48,757.10
Fixed maturities, trading	609.4	563.1
Equity securities, trading	807.6	716.9
Real estate	1,352.10	1,271.60
Other investments	2,990.90	2,944.40
Other investments measured at fair value under fair value option	124.2	142.9
Separate account assets	138,296.70	130,018.40
Long-term debt	2,529.20	2,601.40
Separate account liabilities	138,296.70	130,018.40
Other liabilities	4,984.60	5,224.20
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, authorized (in shares)	2,500	2,500
Common stock, issued (in shares)	462.4	459.3
Common stock, outstanding (in shares)	293.6	295.2
Treasury stock (in shares)	168.8	164.1
Series A	'	'
Preferred stock, par value (in dollars per share)	$0.01	$0.01
Preferred stock, liquidation preference (in dollars per share)	$100	$100
Preferred stock, authorized (in shares)	3	3
Preferred stock, issued (in shares)	3	3
Preferred stock, outstanding (in shares)	3	3
Series B	'	'
Preferred stock, par value (in dollars per share)	$0.01	$0.01
Preferred stock, liquidation preference (in dollars per share)	$25	$25
Preferred stock, authorized (in shares)	10	10
Preferred stock, issued (in shares)	10	10
Preferred stock, outstanding (in shares)	10	10
Aggregate consolidated variable interest entities	'	'
Fixed maturities, available-for-sale	287.2	272
Fixed maturities, trading	100.4	110.4
Equity securities, trading	349.4	327.2
Real estate	276.2	266.3
Other investments	46.2	68.1
Separate account assets	35,079.90	32,824.70
Long-term debt	74.9	47.7
Separate account liabilities	35,079.90	32,824.70
Other liabilities	349.5	362.4
Other liabilities measured at fair value under fair value option	$65.80	$104.90

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues	'	'	'	'
Premiums and other considerations	$875.80	$703	$2,514.80	$2,134.90
Fees and other revenues	884.5	803	2,569.70	2,340.40
Net investment income (loss)	770.4	784.5	2,444.10	2,323.50
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	-24.5	-29.7	105	-109.5
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	-7.3	-11.9	18.5	-81.2
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	-14.6	-9.3	-82.5	8.8
Net impairment losses on available-for-sale securities	-21.9	-21.2	-64	-72.4
Net realized capital gains (losses)	-46.4	-50.9	41	-181.9
Total revenues	2,484.30	2,239.60	7,569.60	6,616.90
Expenses	'	'	'	'
Benefits, claims and settlement expenses	1,113.80	1,096.20	3,609.70	3,286.40
Dividends to policyholders	44.2	48.5	134.5	144.3
Operating expenses	932.5	774.6	2,647.70	2,372.10
Total expenses	2,090.50	1,919.30	6,391.90	5,802.80
Income (loss) before income taxes	393.8	320.3	1,177.70	814.1
Income taxes (benefits)	141	61.2	281.6	128.4
Net income (loss)	252.8	259.1	896.1	685.7
Net income (loss) attributable to noncontrolling interest	3.9	5.2	30.7	14.7
Net income (loss) attributable to Principal Financial Group, Inc.	248.9	253.9	865.4	671
Preferred stock dividends	8.2	8.2	24.7	24.7
Net income (loss) available to common stockholders	$240.70	$245.70	$840.70	$646.30
Earnings per common share	'	'	'	'
Basic earnings per common share (in dollars per share)	$0.78	$0.83	$2.78	$2.20
Diluted earnings per common share (in dollars per share)	$0.77	$0.82	$2.75	$2.17
Dividends declared per common share (in dollars per share)	$0.34	$0.26	$0.94	$0.72

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Consolidated Statements of Comprehensive Income	'	'	'	'
Net income (loss)	$252.80	$259.10	$896.10	$685.70
Other comprehensive income (loss), net:	'	'	'	'
Net unrealized gains (losses) on available-for-sale securities	-73.9	29.3	296.6	-523.7
Noncredit component of impairment losses on fixed maturities, available-for-sale	11	-2.5	48.9	-13.1
Net unrealized gains (losses) on derivative instruments	29.2	-25.1	42.3	-3.4
Foreign currency translation adjustment	-195.8	-33.5	-208.4	-169.5
Net unrecognized postretirement benefit obligation	3.6	13.8	10.7	41.4
Other comprehensive income (loss)	-225.9	-18	190.1	-668.3
Comprehensive income (loss)	26.9	241.1	1,086.20	17.4
Comprehensive income (loss) attributable to noncontrolling interest	-2.7	4.4	23.9	4.4
Comprehensive income (loss) attributable to Principal Financial Group, Inc.	$29.60	$236.70	$1,062.30	$13

Consolidated_Statements_of_Sto

Consolidated Statements of Stockholders' Equity (USD $)	Total	Common stock	Additional paid-in capital	Retained earnings (accumulated deficit)	Accumulated other comprehensive income (loss)	Treasury stock	Noncontrolling interest	Series A	Series B
In Millions, unless otherwise specified
Balances at Dec. 31, 2012	$9,703.40	$4.50	$9,730.90	$4,862	$640.30	($5,554.40)	$20	$0	$0.10
Increase (decrease) in stockholders' equity	'	'	'	'	'	'	'	'	'
Common stock issued	80.2	0.1	80.1	'	'	'	'	'	'
Stock-based compensation and additional related tax benefits	51.3	'	54.7	-3.4	'	'	'	'	'
Treasury stock acquired, common	-153.4	'	'	'	'	-153.4	'	'	'
Dividends to common stockholders	-211.7	'	'	-211.7	'	'	'	'	'
Dividends to preferred stockholders	-24.7	'	'	-24.7	'	'	'	'	'
Contributions from noncontrolling interest	115.7	'	'	'	'	'	115.7	'	'
Purchase of subsidiary shares from noncontrolling interest	-51.4	'	1.8	'	'	'	-53.2	'	'
Sale of subsidiary shares to noncontrolling interest	31.8	'	11.5	'	'	'	20.3	'	'
Adjustments to redemption amount of redeemable noncontrolling interest	-179.5	'	-129.7	-43.3	'	'	-6.5	'	'
Net income (loss) (excludes $8.3 million and $9.0 million attributable to redeemable noncontrolling interest in 2014 and 2013 respectively)	676.7	'	'	671	'	'	5.7	'	'
Other comprehensive income (loss) (excludes $(1.5) million and $(3.3) million attributable to redeemable noncontrolling interest in 2014 and 2013 respectively)	-665	'	'	'	-658	'	-7	'	'
Balances at Sep. 30, 2013	9,373.40	4.6	9,749.30	5,249.90	-17.7	-5,707.80	95	0	0.1
Balances at Dec. 31, 2013	9,777	4.6	9,798.90	5,405.40	183.2	-5,708	92.8	0	0.1
Increase (decrease) in stockholders' equity	'	'	'	'	'	'	'	'	'
Common stock issued	69.6	'	69.6	'	'	'	'	'	'
Stock-based compensation and additional related tax benefits	57.8	'	62.3	-4.5	'	'	'	'	'
Treasury stock acquired, common	-222.5	'	'	'	'	-222.5	'	'	'
Dividends to common stockholders	-276.7	'	'	-276.7	'	'	'	'	'
Dividends to preferred stockholders	-24.7	'	'	-24.7	'	'	'	'	'
Distributions to noncontrolling interest	-22.9	'	'	'	'	'	-22.9	'	'
Contributions from noncontrolling interest	7.1	'	'	'	'	'	7.1	'	'
Purchase of subsidiary shares from noncontrolling interest	-41.9	'	-0.4	'	'	'	-41.5	'	'
Adjustments to redemption amount of redeemable noncontrolling interest	-33.2	'	-13.5	-19.7	'	'	'	'	'
Net income (loss) (excludes $8.3 million and $9.0 million attributable to redeemable noncontrolling interest in 2014 and 2013 respectively)	887.8	'	'	865.4	'	'	22.4	'	'
Other comprehensive income (loss) (excludes $(1.5) million and $(3.3) million attributable to redeemable noncontrolling interest in 2014 and 2013 respectively)	191.6	'	'	'	196.9	'	-5.3	'	'
Balances at Sep. 30, 2014	$10,369	$4.60	$9,916.90	$5,945.20	$380.10	($5,930.50)	$52.60	$0	$0.10

Consolidated_Statements_of_Sto1

Consolidated Statements of Stockholders' Equity (Parenthetical) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Consolidated Statements of Stockholders' Equity	'	'
Net income (loss) attributable to redeemable noncontrolling interest	$8.30	$9
Other comprehensive income (loss) attributable to redeemable noncontrolling interest	($1.50)	($3.30)

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Operating activities	'	'
Net income (loss)	$896.10	$685.70
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:	'	'
Amortization of deferred acquisition costs	282.8	136
Additions to deferred acquisition costs	-291.8	-338.5
Accrued investment income	-13	13.2
Net cash flows for trading securities	-47.8	-40.5
Premiums due and other receivables	85	-43.8
Contractholder and policyholder liabilities and dividends	1,211.40	993
Current and deferred income taxes (benefits)	204.3	175.6
Net realized capital (gains) losses	-41	181.9
Depreciation and amortization expense	122.8	114.5
Mortgage loans held for sale, sold or repaid, net of gain	8.4	0.2
Real estate acquired through operating activities	-43.6	-81.5
Real estate sold through operating activities	146.1	12.2
Stock-based compensation	58.4	51.7
Other	-380.5	-461.8
Net adjustments	1,301.50	712.2
Net cash provided by (used in) operating activities	2,197.60	1,397.90
Investing activities	'	'
Available-for-sale securities: Purchases	-6,596	-7,012.30
Available-for-sale securities: Sales	1,871.50	1,626.70
Available-for-sale securities: Maturities	4,499.30	5,783.20
Mortgage loans acquired or originated	-1,614.20	-2,020
Mortgage loans sold or repaid	1,319.80	1,570.80
Real estate acquired	-246.8	-59
Net (purchases) sales of property and equipment	-117.5	-22.7
Purchases of interest in subsidiaries, net of cash acquired	'	-1,268.30
Net change in other investments	56.6	-31.2
Net cash provided by (used in) investing activities	-827.3	-1,432.80
Financing activities	'	'
Issuance of common stock	69.6	80.2
Acquisition of treasury stock	-222.5	-153.4
Proceeds from financing element derivatives	14.9	46.7
Payments for financing element derivatives	-41.5	-36.9
Excess tax benefits from share-based payment arrangements	8.6	8.6
Purchase of subsidiary shares from noncontrolling interest	-222.4	-51.4
Sale of subsidiary shares to noncontrolling interest	'	31.8
Dividends to common stockholders	-276.7	-211.7
Dividends to preferred stockholders	-24.7	-24.7
Issuance of long-term debt	36.5	24.1
Principal repayments of long-term debt	-100.3	-212.2
Net proceeds from (repayments of) short-term borrowings	-20.5	131.6
Investment contract deposits	4,184.30	5,270.20
Investment contract withdrawals	-5,864.30	-7,055.60
Net increase (decrease) in banking operation deposits	-2.3	-276.2
Other	-10	-6.3
Net cash provided by (used in) financing activities	-2,471.30	-2,435.20
Net increase (decrease) in cash and cash equivalents	-1,101	-2,470.10
Cash and cash equivalents at beginning of period	2,371.80	4,177.20
Cash and cash equivalents at end of period	$1,270.80	$1,707.10

Nature_of_Operations_and_Signi

Nature of Operations and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2014
Nature of Operations and Significant Accounting Policies	'
Nature of Operations and Significant Accounting Policies	'
	1.  Nature of Operations and Significant Accounting Policies
	Basis of Presentation
	The accompanying unaudited consolidated financial statements of Principal Financial Group, Inc. (“PFG”), its majority-owned subsidiaries and its consolidated variable interest entities (“VIEs”), have been prepared in conformity with accounting principles generally accepted in the U.S. (“U.S. GAAP”) for interim financial statements and with the instructions to Form 10-Q and Article 10 of Regulation S-X. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three and nine months ended September 30, 2014, are not necessarily indicative of the results that may be expected for the year ended December 31, 2014. These interim unaudited consolidated financial statements should be read in conjunction with our annual audited financial statements as of December 31, 2013, included in our Form 10-K for the year ended December 31, 2013, filed with the United States Securities and Exchange Commission (“SEC”). The accompanying consolidated statement of financial position as of December 31, 2013, has been derived from the audited consolidated statement of financial position but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements.
	Recent Accounting Pronouncements
	In August 2014, the Financial Accounting Standards Board (“FASB”) issued authoritative guidance about management’s responsibility to evaluate whether there are conditions or events that raise substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosures. This guidance will be effective for us December 31, 2016, and is not expected to have a material impact on our consolidated financial statements.
	Also in August 2014, the FASB issued authoritative guidance related to measuring the financial assets and the financial liabilities of a consolidated collateralized financing entity, such as a collateralized debt obligation or collateralized loan obligation. This guidance will be effective for us on January 1, 2016, and is not expected to have a material impact on our consolidated financial statements.
	In June 2014, the FASB issued authoritative guidance that a performance target in a share-based payment that affects vesting and that could be achieved after the requisite service period should be accounted for as a performance condition. This guidance will be effective for us on January 1, 2016, with early adoption permitted. This guidance is not expected to have a material impact on our consolidated financial statements.
	Also in June 2014, the FASB issued authoritative guidance that amends current accounting and disclosures for repurchase agreements and similar transactions. This guidance will be effective for us on January 1, 2015, and is not expected to have a material impact on our consolidated financial statements.
	In May 2014, the FASB issued authoritative guidance on revenue recognition that replaces all general and most industry specific revenue guidance currently prescribed by U.S. GAAP. The core principle of the revenue standard is that an entity recognizes revenue to reflect the transfer of a promised good or service to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for that good or service. The guidance will be effective for us on January 1, 2017, and early adoption is not permitted. An entity may apply the new guidance using one of the following two methods:  (1) retrospectively to each prior reporting period presented, or (2) retrospectively with the cumulative effect of initially applying the standard recognized at the date of initial application. We are currently evaluating the impact this guidance will have on our consolidated financial statements.
	In April 2014, the FASB issued authoritative guidance related to discontinued operations which amends the definition of a discontinued operation and requires entities to provide additional disclosures associated with discontinued operations, as well as disposal transactions that do not meet the discontinued operations criteria. The guidance requires discontinued operations treatment for disposals of a component or group of components that represents a strategic shift that has or will have a major impact on an entity’s operations or financial results. The guidance also expands the scope to disposals of equity method investments and businesses that, upon initial acquisition, qualify as held for sale. This guidance will be effective for us beginning January 1, 2015, and early adoption is permitted. We do not expect this guidance to have a material impact on our consolidated financial statements.
	In January 2014, the FASB issued authoritative guidance to reduce diversity in practice by clarifying when an in substance repossession or foreclosure occurs. This guidance will be effective for us beginning January 1, 2015, and is not expected to have a material impact on our consolidated financial statements.
	Also, in January 2014, the FASB issued authoritative guidance on accounting for investments by a reporting entity in flow-through limited liability entities that manage or invest in affordable housing projects that qualify for the low-income housing tax credit. This guidance will be effective for us beginning January 1, 2015, and is not expected to have a material impact on our consolidated financial statements.
	In July 2013, the FASB issued authoritative guidance that requires the liability related to certain unrecognized benefits to be offset against a deferred tax asset from operating loss carryforwards. This guidance was effective for us beginning January 1, 2014, and did not have a material impact on our consolidated financial statements.
	In June 2013, the FASB issued authoritative guidance that formalizes the definition of an investment company. This guidance was effective for us beginning January 1, 2014, and did not have a material impact on our consolidated financial statements.
	In March 2013, the FASB issued authoritative guidance that clarifies how the cumulative translation adjustment related to a parent’s investment in a foreign entity should be released when certain transactions related to the foreign entity occur. This guidance was effective prospectively for us beginning January 1, 2014, and did not have a material impact on our consolidated financial statements.
	Separate Accounts
	The separate accounts are legally segregated and are not subject to the claims that arise out of any of our other business. The client, rather than us, directs the investments and bears the investment risk of these funds. The separate account assets represent the fair value of funds that are separately administered by us for contracts with equity, real estate and fixed income investments and are presented as a summary total within the consolidated statements of financial position. An equivalent amount is reported as separate account liabilities, which represent the obligation to return the monies to the client. We receive fees for mortality, withdrawal and expense risks, as well as administrative, maintenance and investment advisory services that are included in the consolidated statements of operations. Net deposits, net investment income and realized and unrealized capital gains and losses of the separate accounts are not reflected in the consolidated statements of operations. Separate account assets and separate account liabilities include certain non-domestic retirement accumulation products where the segregated funds and associated obligation to the client are consolidated within our financial statements. We have determined that summary totals are the most meaningful presentation for these funds.
	At September 30, 2014 and December 31, 2013, the separate account assets include a separate account valued at $216.0 million and $223.1 million, respectively, which primarily includes shares of our stock that were allocated and issued to eligible participants of qualified employee benefit plans administered by us as part of the policy credits issued under our 2001 demutualization. These shares are included in both basic and diluted earnings per share calculations. In the consolidated statements of financial position, the separate account shares are recorded at fair value and are reported as separate account assets with a corresponding separate account liability to eligible participants of the qualified plan. Changes in fair value of the separate account shares are reflected in both the separate account assets and separate account liabilities and do not impact our results of operations.

Variable_Interest_Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2014
Variable Interest Entities	'
Variable Interest Entities	'
	2.  Variable Interest Entities
	We have relationships with and may have a variable interest in various types of special purpose entities. Following is a discussion of our interest in entities that meet the definition of a VIE. When we are the primary beneficiary, we are required to consolidate the entity in our financial statements. The primary beneficiary of a VIE is defined as the enterprise with (1) the power to direct the activities of a VIE that most significantly impact the entity’s economic performance and (2) the obligation to absorb losses of the entity or the right to receive benefits from the entity that could potentially be significant to the VIE. For VIEs that are investment companies, the primary beneficiary is the enterprise who absorbs the majority of the entity’s expected losses, receives a majority of the expected residual returns or both. On an ongoing basis, we assess whether we are the primary beneficiary of VIEs in which we have a relationship.
	Consolidated Variable Interest Entities
	Grantor Trusts
	We contributed undated subordinated floating rate notes to three grantor trusts. The trusts separated the cash flows by issuing an interest-only certificate and a residual certificate related to each note contributed. Each interest-only certificate entitles the holder to interest on the stated note for a specified term, while the residual certificate entitles the holder to interest payments subsequent to the term of the interest-only certificate and to all principal payments. We retained the interest-only certificates and the residual certificates were subsequently sold to third parties. We have determined these grantor trusts are VIEs due to insufficient equity to sustain them. We determined we are the primary beneficiary as a result of our contribution of securities into the trusts and our continuing interest in the trusts.
	Collateralized Private Investment Vehicle
	We invest in synthetic collateralized debt obligations, collateralized bond obligations, collateralized loan obligations and other collateralized structures, which are VIEs due to insufficient equity to sustain the entities (collectively known as “collateralized private investment vehicles”). The performance of the notes of these structures is primarily linked to a synthetic portfolio by derivatives; each note has a specific loss attachment and detachment point. The notes and related derivatives are collateralized by a pool of permitted investments. The investments are held by a trustee and can only be liquidated to settle obligations of the trusts. These obligations primarily include derivatives and the notes due at maturity or termination of the trusts. We determined we are the primary beneficiary for one of these entities because we act as the investment manager of the underlying portfolio and we have an ownership interest.
	Commercial Mortgage-Backed Securities
	We sold commercial mortgage loans to a real estate mortgage investment conduit trust. The trust issued various commercial mortgage-backed securities (“CMBS”) certificates using the cash flows of the underlying commercial mortgages it purchased. This is considered a VIE due to insufficient equity to sustain itself. We have determined we are the primary beneficiary as we retained the special servicing role for the assets within the trust as well as the ownership of the bond class that controls the unilateral kick out rights of the special servicer.
	Mandatory Retirement Savings
	We hold an equity interest in Chilean mandatory privatized social security funds in which we provide asset management services. We determined that the mandatory privatized social security funds, which include contributors for voluntary pension savings, voluntary non-pension savings and compensation savings accounts, are VIEs. This is because the equity holders as a group lack the power, due to voting rights or similar rights, to direct the activities of the entity that most significantly impact the entity’s economic performance and also because equity investors are protected from below-average market investment returns relative to the industry’s return, due to a regulatory guarantee that we provide. Further we concluded that we are the primary beneficiary through our power to make decisions and our variable interest in the funds. The purpose of the funds, which reside in legally segregated entities, is to provide long-term retirement savings. The obligation to the client is directly related to the assets held in the funds and, as such, we present the assets as separate account assets and the obligation as separate account liabilities within our consolidated statements of financial position.
	Real Estate
	During the third quarter of 2014, we re-evaluated our consolidation conclusions for certain real estate limited partnerships and limited liability companies. We determined the entities were properly consolidated in the financial statements, but should have been consolidated under the VIE model as opposed to the voting interest model. As a result, we have included the consolidation impacts of these entities within the current and prior period VIE disclosures.
	We invest in several real estate limited partnerships and limited liability companies. The entities invest in real estate properties. These entities are VIEs based on the combination of our significant economic interest and related voting rights. We determined we are the primary beneficiary as a result of our power to control the entities through our significant ownership.
	The carrying amounts of our consolidated VIE assets, which can only be used to settle obligations of consolidated VIEs, and liabilities of consolidated VIEs for which creditors do not have recourse are as follows:
				Collateralized
				private				Mandatory
		Grantor		investment				retirement
		trusts		vehicle		CMBS		savings		Real estate		Total
						(in millions)
	September 30, 2014
	Fixed maturities, available-for-sale	$	287.2	$	—	$	—	$	—	$	—	$	287.2
	Fixed maturities, trading	—		100.4		—		—		—		100.4
	Equity securities, trading	—		—		—		349.4		—		349.4
	Real estate	—		—		—		—		276.2		276.2
	Other investments	—		—		41.9		—		4.3		46.2
	Cash	—		—		—		—		6.2		6.2
	Accrued investment income	0.4		—		0.2		—		1.5		2.1
	Separate account assets	—		—		—		35,079.90		—		35,079.90
	Other assets	—		—		—		—		0.2		0.2
	Total assets	$	287.6	$	100.4	$	42.1	$	35,429.30	$	288.4	$	36,147.80
	Long-term debt	$	—	$	—	$	—	$	—	$	74.9	$	74.9
	Deferred income taxes	1.6		—		—		—		—		1.6
	Separate account liabilities	—		—		—		35,079.90		—		35,079.90
	Other liabilities (1)	242		86.9		4.9		—		15.7		349.5
	Total liabilities	$	243.6	$	86.9	$	4.9	$	35,079.90	$	90.6	$	35,505.90
	December 31, 2013
	Fixed maturities, available-for-sale	$	272	$	—	$	—	$	—	$	—	$	272
	Fixed maturities, trading	—		110.4		—		—		—		110.4
	Equity securities, trading	—		—		—		327.2		—		327.2
	Real estate	—		—		—		—		266.3		266.3
	Other investments	—		—		68.1		—		—		68.1
	Cash	—		—		—		—		12		12
	Accrued investment income	0.3		—		0.6		—		1.1		2
	Separate account assets	—		—		—		32,824.70		—		32,824.70
	Other assets	—		—		—		—		0.1		0.1
	Total assets	$	272.3	$	110.4	$	68.7	$	33,151.90	$	279.5	$	33,882.80
	Long-term debt	$	—	$	—	$	—	$	—	$	47.7	$	47.7
	Deferred income taxes	1.5		—		—		—		—		1.5
	Separate account liabilities	—		—		—		32,824.70		—		32,824.70
	Other liabilities (1)	217.2		93.8		31.4		—		20		362.4
	Total liabilities	$	218.7	$	93.8	$	31.4	$	32,824.70	$	67.7	$	33,236.30
	(1)            Grantor trusts contain an embedded derivative of a forecasted transaction to deliver the underlying securities; the collateralized private investment vehicle includes derivative liabilities and an obligation to redeem notes at maturity or termination of the trust.
	We did not provide financial or other support to investees designated as VIEs for the periods ended September 30, 2014 and December 31, 2013.
	Unconsolidated Variable Interest Entities
	Invested Securities
	We hold a variable interest in a number of VIEs where we are not the primary beneficiary. Our investments in these VIEs are reported in fixed maturities, available-for-sale; fixed maturities, trading and other investments in the consolidated statements of financial position and are described below.
	Unconsolidated VIEs include CMBS, residential mortgage-backed pass-through securities (“RMBS”) and other asset-backed securities (“ABS”). All of these entities were deemed VIEs because the equity within these entities is insufficient to sustain them. We determined we are not the primary beneficiary in the entities within these categories of investments. This determination was based primarily on the fact we do not own the class of security that controls the unilateral right to replace the special servicer or equivalent function.
	As previously discussed, we invest in several types of collateralized private investment vehicles, which are VIEs. These include cash and synthetic structures that we do not manage. We have determined we are not the primary beneficiary of these collateralized private investment vehicles primarily because we do not control the economic performance of the entities and were not involved with the design of the entities.
	We have invested in various VIE trusts as a debt holder. All of these entities are classified as VIEs due to insufficient equity to sustain them. We have determined we are not the primary beneficiary primarily because we do not control the economic performance of the entities and were not involved with the design of the entities.
	We have invested in partnerships, some of which are classified as VIEs. The returns from the partnerships are in the form of income tax credits and investment income. These entities are classified as VIEs as the general partner does not have an equity investment at risk in the entity. We have determined we are not the primary beneficiary because we are not the general partner, who makes all the significant decisions for the entity or our variable interest does not absorb the majority of the variability of the entities’ net assets.
	The carrying value and maximum loss exposure for our unconsolidated VIEs were as follows:
				Maximum exposure to
	Asset carrying value		loss (1)
	(in millions)
September 30, 2014
Fixed maturities, available-for-sale:
Corporate	$	493.4	$	393.9
Residential mortgage-backed pass-through securities	2,809.00		2,714.50
Commercial mortgage-backed securities	4,012.30		3,925.80
Collateralized debt obligations	480.8		493.5
Other debt obligations	4,414.40		4,385.00
Fixed maturities, trading:
Residential mortgage-backed pass-through securities	37.3		37.3
Commercial mortgage-backed securities	1.4		1.4
Collateralized debt obligations	38.9		38.9
Other debt obligations	0.5		0.5
Other investments:
Other limited partnership interests	154.5		154.5
December 31, 2013
Fixed maturities, available-for-sale:
Corporate	$	523.4	$	448.2
Residential mortgage-backed pass-through securities	2,845.20		2,799.10
Commercial mortgage-backed securities	4,026.40		4,078.00
Collateralized debt obligations	363.4		391.9
Other debt obligations	4,167.80		4,157.50
Fixed maturities, trading:
Residential mortgage-backed pass-through securities	47.5		47.5
Commercial mortgage-backed securities	1.8		1.8
Collateralized debt obligations	59.6		59.6
Other debt obligations	1.2		1.2
Other investments:
Other limited partnership interests	123.5		123.5
(1)         Our risk of loss is limited to our initial investment measured at amortized cost for fixed maturities, available-for-sale and other investments. Our risk of loss is limited to our investment measured at fair value for our fixed maturities, trading.
Sponsored Investment Funds
We are the investment manager for certain money market mutual funds that are deemed to be VIEs. We are not the primary beneficiary of these VIEs since our involvement is limited primarily to being a service provider, and our variable interest does not absorb the majority of the variability of the entities’ net assets. As of both September 30, 2014 and December 31, 2013, these VIEs held $1.4 billion in total assets. We have no contractual obligation to contribute to the funds.
We provide asset management and other services to certain investment structures that are considered VIEs as we generally earn performance-based management fees. We are not the primary beneficiary of these entities as we do not have the obligation to absorb losses of the entities that could be potentially significant to the VIE or the right to receive benefits from these entities that could be potentially significant.

Investments

Investments	9 Months Ended
	Sep. 30, 2014
Investments	'
Investments	'
	3.  Investments
	Fixed Maturities and Equity Securities
	Fixed maturities include bonds, ABS, redeemable preferred stock and certain nonredeemable preferred securities. Equity securities include mutual funds, common stock, nonredeemable preferred stock and mandatory regulatory required investments. We classify fixed maturities and equity securities as either available-for-sale or trading at the time of the purchase and, accordingly, carry them at fair value. See Note 9, Fair Value Measurements, for methodologies related to the determination of fair value. Unrealized gains and losses related to available-for-sale securities, excluding those in fair value hedging relationships, are reflected in stockholders’ equity, net of adjustments related to deferred acquisition costs (“DAC”), sales inducements, unearned revenue reserves, policyholder liabilities, derivatives in cash flow hedge relationships and applicable income taxes. Unrealized gains and losses related to hedged portions of available-for-sale securities in fair value hedging relationships and mark-to-market adjustments on certain trading securities are reflected in net realized capital gains (losses). We have assets within the trading securities that represent mandatory regulatory required investments. Mark-to-market adjustments related to these trading securities are reflected in net investment income.
	The cost of fixed maturities is adjusted for amortization of premiums and accrual of discounts, both computed using the interest method. The cost of fixed maturities and equity securities classified as available-for-sale is adjusted for declines in value that are other than temporary. Impairments in value deemed to be other than temporary are primarily reported in net income as a component of net realized capital gains (losses), with noncredit impairment losses for certain fixed maturities, available-for-sale reported in other comprehensive income (“OCI”). For loan-backed and structured securities, we recognize income using a constant effective yield based on currently anticipated cash flows.
	The amortized cost, gross unrealized gains and losses, other-than-temporary impairments in accumulated other comprehensive income (“AOCI”) and fair value of fixed maturities and equity securities available-for-sale are summarized as follows:
															Other-than-
						Gross			Gross						temporary
			Amortized			unrealized			unrealized						impairments in
			cost			gains			losses			Fair value			AOCI (1)
			(in millions)
	September 30, 2014
	Fixed maturities, available-for-sale:
	U.S. government and agencies		$	882.2		$	18.3		$	8.4		$	892.1		$	—
	Non-U.S. governments		736.7			168.9			0.9			904.7			—
	States and political subdivisions		3,875.80			233.9			15.7			4,094.00			—
	Corporate		29,762.30			2,414.40			156.5			32,020.20			19.4
	Residential mortgage-backed pass-through securities		2,714.50			109.8			15.3			2,809.00			—
	Commercial mortgage-backed securities		3,925.80			164.7			78.2			4,012.30			105.5
	Collateralized debt obligations		493.5			7			19.7			480.8			1.2
	Other debt obligations		4,385.00			55.7			26.3			4,414.40			68.8
	Total fixed maturities, available-for-sale		$	46,775.80		$	3,172.70		$	321		$	49,627.50		$	194.9
	Total equity securities, available-for-sale		$	126.8		$	8.4		$	10.4		$	124.8
	December 31, 2013
	Fixed maturities, available-for-sale:
	U.S. government and agencies		$	818.2		$	12.7		$	50.4		$	780.5		$	—
	Non-U.S. governments		853.2			148.8			5.2			996.8			—
	States and political subdivisions		3,622.80			120.9			85.7			3,658.00			—
	Corporate		30,280.60			1,958.80			320.4			31,919.00			17.1
	Residential mortgage-backed pass-through securities		2,799.10			92.8			46.7			2,845.20			—
	Commercial mortgage-backed securities		4,078.00			170.6			222.2			4,026.40			183.4
	Collateralized debt obligations		391.9			6			34.5			363.4			0.7
	Other debt obligations		4,157.50			51.8			41.5			4,167.80			76.3
	Total fixed maturities, available-for-sale		$	47,001.30		$	2,562.40		$	806.6		$	48,757.10		$	277.5
	Total equity securities, available-for-sale		$	113.8		$	10		$	13.3		$	110.5
	(1)         Excludes $186.6 million and $148.6 million as of September 30, 2014 and December 31, 2013, respectively, of net unrealized gains on impaired fixed maturities, available-for-sale related to changes in fair value subsequent to the impairment date, which are included in gross unrealized gains and gross unrealized losses.
	The amortized cost and fair value of fixed maturities available-for-sale at September 30, 2014, by expected maturity, were as follows:
			Amortized cost			Fair value
			(in millions)
	Due in one year or less		$	2,886.80		$	2,924.30
	Due after one year through five years		12,618.50			13,221.60
	Due after five years through ten years		8,167.60			8,694.80
	Due after ten years		11,584.10			13,070.30
	Subtotal		35,257.00			37,911.00
	Mortgage-backed and other asset-backed securities		11,518.80			11,716.50
	Total		$	46,775.80		$	49,627.50
	Actual maturities may differ because borrowers may have the right to call or prepay obligations. Our portfolio is diversified by industry, issuer and asset class. Credit concentrations are managed to established limits.
	Net Realized Capital Gains and Losses
	Net realized capital gains and losses on sales of investments are determined on the basis of specific identification. In addition to realized capital gains and losses on investment sales and periodic settlements on derivatives not designated as hedges, we report gains and losses related to the following in net realized capital gains (losses): other-than-temporary impairments of securities and subsequent realized recoveries, mark-to-market adjustments on certain trading securities, mark-to-market adjustments on certain seed money investments, fair value hedge and cash flow hedge ineffectiveness, mark-to-market adjustments on derivatives not designated as hedges, changes in the mortgage loan valuation allowance provision and impairments of real estate held for investment. Investment gains and losses on sales of certain real estate held for sale, which do not meet the criteria for classification as a discontinued operation, and mark-to-market adjustments on trading securities that represent mandatory regulatory required investments are reported as net investment income and are excluded from net realized capital gains (losses). The major components of net realized capital gains (losses) on investments are summarized as follows:
			For the three months ended						For the nine months ended
			September 30,						September 30,
			2014			2013			2014			2013
			(in millions)
	Fixed maturities, available-for-sale:
	Gross gains		$	9.6		$	5.8		$	73.8		$	27.6
	Gross losses		(13.6		)	(18.2		)	(36.6		)	(98.6		)
	Other-than-temporary impairment losses reclassified to (from) OCI		(14.6		)	(9.3		)	(82.5		)	8.8
	Hedging, net		(21.5		)	(9.6		)	(20.0		)	(99.4		)
	Fixed maturities, trading		9.5			2.1			32			(4.1		)
	Equity securities, available-for-sale:
	Gross gains		—			0.7			5.8			0.8
	Gross losses		(0.3		)	—			(0.3		)	(0.1		)
	Equity securities, trading		9.1			0.1			18.7			11.6
	Mortgage loans		(12.0		)	(3.3		)	(10.6		)	(20.3		)
Derivatives		(2.0		)	(34.8		)	1.9			(4.8		)
Other		(10.6		)	15.6			58.8			(3.4		)
Net realized capital gains (losses)		$	(46.4	)	$	(50.9	)	$	41		$	(181.9	)
Proceeds from sales of investments (excluding call and maturity proceeds) in fixed maturities, available-for-sale were $437.1 million and $413.7 million for the three months ended September 30, 2014 and 2013, and $1,744.6 million and $1,515.9 million for the nine months ended September 30, 2014 and 2013, respectively.
Other-Than-Temporary Impairments
We have a process in place to identify fixed maturity and equity securities that could potentially have a credit impairment that is other than temporary. This process involves monitoring market events that could impact issuers’ credit ratings, business climate, management changes, litigation and government actions and other similar factors. This process also involves monitoring late payments, pricing levels, downgrades by rating agencies, key financial ratios, financial statements, revenue forecasts and cash flow projections as indicators of credit issues.
Each reporting period, all securities are reviewed to determine whether an other-than-temporary decline in value exists and whether losses should be recognized. We consider relevant facts and circumstances in evaluating whether a credit or interest-related impairment of a security is other than temporary. Relevant facts and circumstances considered include: (1) the extent and length of time the fair value has been below cost; (2) the reasons for the decline in value; (3) the financial position and access to capital of the issuer, including the current and future impact of any specific events; (4) for structured securities, the adequacy of the expected cash flows; (5) for fixed maturities, our intent to sell a security or whether it is more likely than not we will be required to sell the security before the recovery of its amortized cost which, in some cases, may extend to maturity and (6) for equity securities, our ability and intent to hold the security for a period of time that allows for the recovery in value. To the extent we determine that a security is deemed to be other than temporarily impaired, an impairment loss is recognized.
Impairment losses on equity securities are recognized in net income and are measured as the difference between amortized cost and fair value. The way in which impairment losses on fixed maturities are recognized in the financial statements is dependent on the facts and circumstances related to the specific security. If we intend to sell a security or it is more likely than not that we would be required to sell a security before the recovery of its amortized cost, we recognize an other-than-temporary impairment in net income for the difference between amortized cost and fair value. If we do not expect to recover the amortized cost basis, we do not plan to sell the security and if it is not more likely than not that we would be required to sell a security before the recovery of its amortized cost, the recognition of the other-than-temporary impairment is bifurcated. We recognize the credit loss portion in net income and the noncredit loss portion in OCI (“bifurcated OTTI”).
Total other-than-temporary impairment losses, net of recoveries from the sale of previously impaired securities, were as follows:
		For the three months ended						For the nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
Fixed maturities, available-for-sale		$	(7.1	)	$	(11.9	)	$	13		$	(81.1	)
Equity securities, available-for-sale		(0.2		)	—			5.5			(0.1		)
Total other-than-temporary impairment losses, net of recoveries from the sale of previously impaired securities		(7.3		)	(11.9		)	18.5			(81.2		)
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) OCI (1)		(14.6		)	(9.3		)	(82.5		)	8.8
Net impairment losses on available-for-sale securities		$	(21.9	)	$	(21.2	)	$	(64.0	)	$	(72.4	)
-1	Represents the net impact of (a) gains resulting from reclassification of noncredit impairment losses for fixed maturities with bifurcated OTTI from net realized capital gains (losses) to OCI and (b) losses resulting from reclassification of previously recognized noncredit impairment losses from OCI to net realized capital gains (losses) for fixed maturities with bifurcated OTTI that had additional credit losses or fixed maturities that previously had bifurcated OTTI that have now been sold or are intended to be sold.
We estimate the amount of the credit loss component of a fixed maturity security impairment as the difference between amortized cost and the present value of the expected cash flows of the security. The present value is determined using the best estimate cash flows discounted at the effective interest rate implicit to the security at the date of purchase or the current yield to accrete an asset-backed or floating rate security. The methodology and assumptions for establishing the best estimate cash flows vary depending on the type of security. The ABS cash flow estimates are based on security specific facts and circumstances that may include collateral characteristics, expectations of delinquency and default rates, loss severity and prepayment speeds and structural support, including subordination and guarantees. The corporate security cash flow estimates are derived from scenario-based outcomes of expected corporate restructurings or liquidations using bond specific facts and circumstances including timing, security interests and loss severity.
The following table provides a rollforward of accumulated credit losses for fixed maturities with bifurcated credit losses. The purpose of the table is to provide detail of (1) additions to the bifurcated credit loss amounts recognized in net realized capital gains (losses) during the period and (2) decrements for previously recognized bifurcated credit losses where the loss is no longer bifurcated and/or there has been a positive change in expected cash flows or accretion of the bifurcated credit loss amount.
		For the three months ended						For the nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
Beginning balance		$	(185.7	)	$	(301.5	)	$	(235.4	)	$	(335.2	)
Credit losses for which an other-than-temporary impairment was not previously recognized		(2.2		)	(4.9		)	(6.1		)	(11.1		)
Credit losses for which an other-than-temporary impairment was previously recognized		(21.0		)	(18.9		)	(65.5		)	(54.0		)
Reduction for credit losses previously recognized on fixed maturities now sold, paid down or intended to be sold		18			14.6			112			83.1
Net reduction for positive changes in cash flows expected to be collected and amortization (1)		1.5			2.7			5.6			9.2
Ending balance		$	(189.4	)	$	(308.0	)	$	(189.4	)	$	(308.0	)
(1)   Amounts are recognized in net investment income.
Gross Unrealized Losses for Fixed Maturities and Equity Securities
For fixed maturities and equity securities available-for-sale with unrealized losses, including other-than-temporary impairment losses reported in OCI, the gross unrealized losses and fair value, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position are summarized as follows:
		September 30, 2014
		Less than						Greater than or
		twelve months						equal to twelve months						Total
					Gross						Gross					Gross
		Fair			unrealized			Fair			unrealized			Fair		unrealized
		value			losses			value			losses			value		losses
		(in millions)
Fixed maturities, available-for-sale:
U.S. government and agencies		$	258.7		$	1.2		$	210.5		$	7.2		$	469.2	$	8.4
Non-U.S. governments		36			0.6			11.6			0.3			47.6		0.9
States and political subdivisions		169.8			1.3			359.5			14.4			529.3		15.7
Corporate		2,489.20			24.9			1,459.50			131.6			3,948.70		156.5
Residential mortgage-backed pass-through securities		175.7			0.7			504.1			14.6			679.8		15.3
Commercial mortgage-backed securities		315.1			3			472.4			75.2			787.5		78.2
Collateralized debt obligations		147.5			1.6			82.9			18.1			230.4		19.7
Other debt obligations		867.9			3.3			486.2			23			1,354.10		26.3
Total fixed maturities, available-for-sale		$	4,459.90		$	36.6		$	3,586.70		$	284.4		$	8,046.60	$	321
Total equity securities, available-for-sale		$	—		$	—		$	50.9		$	10.4		$	50.9	$	10.4
Of the total amounts, Principal Life Insurance Company’s (“Principal Life”) consolidated portfolio represented $7,833.3 million in available-for-sale fixed maturities with gross unrealized losses of $296.7 million. Of those fixed maturity securities in Principal Life’s consolidated portfolio with a gross unrealized loss position, 83% were investment grade (rated AAA through BBB-) with an average price of 96 (carrying value/amortized cost) at September 30, 2014. Gross unrealized losses in our fixed maturities portfolio decreased during the nine months ended September 30, 2014, due to a decrease in interest rates and spread improvements.
For those securities that had been in a continuous unrealized loss position for less than twelve months, Principal Life’s consolidated portfolio held 591 securities with a carrying value of $4,426.0 million and unrealized losses of $36.4 million reflecting an average price of 99 at September 30, 2014. Of this portfolio, 79% was investment grade (rated AAA through BBB-) at September 30, 2014, with associated unrealized losses of $24.4 million. The unrealized losses on these securities can primarily be attributed to changes in market interest rates and changes in credit spreads since the securities were acquired.
For those securities that had been in a continuous unrealized loss position greater than or equal to twelve months, Principal Life’s consolidated portfolio held 507 securities with a carrying value of $3,407.3 million and unrealized losses of $260.3 million. The average rating of this portfolio was A with an average price of 93 at September 30, 2014. Of the $260.3 million in unrealized losses, the commercial mortgage-backed securities sector accounts for $75.2 million in unrealized losses with an average price of 86 and an average credit rating of A-. The remaining unrealized losses consist primarily of $108.0 million within the corporate sector at September 30, 2014. The average price of the corporate sector was 92 and the average credit rating was BBB+. The unrealized losses on these securities can primarily be attributed to changes in market interest rates and changes in credit spreads since the securities were acquired.
Because we expected to recover our amortized cost, it was not our intent to sell the fixed maturity available-for-sale securities with unrealized losses and it was not more likely than not that we would be required to sell these securities before recovery of the amortized cost, which may be maturity, we did not consider these investments to be other-than-temporarily impaired at September 30, 2014.
		December 31, 2013
		Less than						Greater than or
		twelve months						equal to twelve months						Total
					Gross						Gross					Gross
		Fair			unrealized			Fair			unrealized			Fair		unrealized
		value			losses			value			losses			value		losses
		(in millions)
Fixed maturities, available-for-sale:
U.S. government and agencies		$	526.8		$	49.6		$	9.2		$	0.8		$	536	$	50.4
Non-U.S. governments		78.1			5.1			5.8			0.1			83.9		5.2
States and political subdivisions		1,338.60			75.3			46.1			10.4			1,384.70		85.7
Corporate		4,087.90			155.4			1,278.10			165			5,366.00		320.4
Residential mortgage-backed pass- through securities		1,150.30			38.2			85.9			8.5			1,236.20		46.7
Commercial mortgage-backed securities		683.7			15.3			495.6			206.9			1,179.30		222.2
Collateralized debt obligations		88.8			1.4			47.4			33.1			136.2		34.5
Other debt obligations		1,359.00			16.1			287.9			25.4			1,646.90		41.5
Total fixed maturities, available-for-sale		$	9,313.20		$	356.4		$	2,256.00		$	450.2		$	11,569.20	$	806.6
Total equity securities, available-for-sale		$	16.7		$	0.3		$	48.3		$	13		$	65	$	13.3
Of the total amounts, Principal Life’s consolidated portfolio represented $10,905.4 million in available-for-sale fixed maturities with gross unrealized losses of $752.5 million. Of those fixed maturity securities in Principal Life’s consolidated portfolio with a gross unrealized loss position, 87% were investment grade (rated AAA through BBB-) with an average price of 94 (carrying value/amortized cost) at December 31, 2013. Gross unrealized losses in our fixed maturities portfolio decreased slightly during the year ended December 31, 2013, due to spread improvements.
For those securities that had been in a continuous unrealized loss position for less than twelve months, Principal Life’s consolidated portfolio held 1,154 securities with a carrying value of $8,899.5 million and unrealized losses of $339.8 million reflecting an average price of 96 at December 31, 2013. Of this portfolio, 94% was investment grade (rated AAA through BBB-) at December 31, 2013, with associated unrealized losses of $325.9 million. The unrealized losses on these securities can primarily be attributed to changes in market interest rates and changes in credit spreads since the securities were acquired.
For those securities that had been in a continuous unrealized loss position greater than or equal to twelve months, Principal Life’s consolidated portfolio held 359 securities with a carrying value of $2,005.9 million and unrealized losses of $412.7 million. The average rating of this portfolio was BBB- with an average price of 83 at December 31, 2013. Of the $412.7 million in unrealized losses, the commercial mortgage-backed securities sector accounts for $206.9 million in unrealized losses with an average price of 71 and an average credit rating of BB-. The remaining unrealized losses consist primarily of $127.6 million within the corporate sector at December 31, 2013. The average price of the corporate sector was 89 and the average credit rating was BBB+. The unrealized losses on these securities can primarily be attributed to changes in market interest rates and changes in credit spreads since the securities were acquired.
Because we expected to recover our amortized cost, it was not our intent to sell the fixed maturity available-for-sale securities with unrealized losses and it was not more likely than not that we would be required to sell these securities before recovery of the amortized cost, which may be maturity, we did not consider these investments to be other-than-temporarily impaired at December 31, 2013.
Net Unrealized Gains and Losses on Available-for-Sale Securities and Derivative Instruments
The net unrealized gains and losses on investments in fixed maturities available-for-sale, equity securities available-for-sale and derivative instruments in cash flow hedge relationships are reported as a separate component of stockholders’ equity. The cumulative amount of net unrealized gains and losses on available-for-sale securities and derivative instruments in cash flow hedge relationships net of adjustments related to DAC, reinsurance assets or liabilities, sales inducements, unearned revenue reserves, changes in policyholder liabilities and applicable income taxes was as follows:
		September 30, 2014			December 31, 2013
		(in millions)
Net unrealized gains on fixed maturities, available-for-sale (1)		$	3,021.10		$	2,067.40
Noncredit component of impairment losses on fixed maturities, available-for-sale		(194.9		)	(277.5		)
Net unrealized losses on equity securities, available-for-sale		(2.0		)	(3.3		)
Adjustments for assumed changes in amortization patterns		(351.1		)	(265.9		)
Adjustments for assumed changes in policyholder liabilities		(1,057.0		)	(621.2		)
Net unrealized gains on derivative instruments		130			56
Net unrealized gains on equity method subsidiaries and noncontrolling interest adjustments		84.6			87.1
Provision for deferred income taxes		(542.3		)	(342.0		)
Net unrealized gains on available-for-sale securities and derivative instruments		$	1,088.40		$	700.6
(1)         Excludes net unrealized gains (losses) on fixed maturities, available-for-sale included in fair value hedging relationships.
Mortgage Loans
Mortgage loans consist of commercial and residential mortgage loans. We evaluate risks inherent in our commercial mortgage loans in two classes: (1) brick and mortar property loans, including mezzanine loans, where we analyze the property’s rent payments as support for the loan, and (2) credit tenant loans (“CTL”), where we rely on the credit analysis of the tenant for the repayment of the loan. We evaluate risks inherent in our residential mortgage loan portfolio in two classes: (1) home equity mortgages and (2) first lien mortgages. The carrying amount of our mortgage loan portfolio was as follows:
		September 30, 2014			December 31, 2013
		(in millions)
Commercial mortgage loans		$	10,596.80		$	10,327.70
Residential mortgage loans		1,206.10			1,275.70
Total amortized cost		11,802.90			11,603.40
Valuation allowance		(58.0		)	(69.8		)
Total carrying value		$	11,744.90		$	11,533.60
We periodically purchase mortgage loans as well as sell mortgage loans we have originated. We purchased $35.6 million and $64.8 million of residential mortgage loans during the three months ended September 30, 2014 and 2013, and $115.7 million and $135.8 million during the nine months ended September 30, 2014 and 2013, respectively. We sold $0.0 million and $0.0 million of residential mortgage loans during the three months ended September 30, 2014 and 2013, and $0.0 million and $0.0 million during the nine months ended September 30, 2014 and 2013, respectively. We purchased $0.0 million and $0.0 million of commercial mortgage loans during the three months ended September 30, 2014 and 2013, and $33.4 million and $141.1 million during the nine months ended September 30, 2014 and 2013, respectively. We sold $0.0 million and $0.0 million of commercial mortgage loans during the three months ended September 30, 2014 and 2013, and $1.1 million and $13.0 million during the nine months ended September 30, 2014 and 2013, respectively.
Our commercial mortgage loan portfolio consists primarily of non-recourse, fixed rate mortgages on stabilized properties. Our commercial mortgage loan portfolio is diversified by geographic region and specific collateral property type as follows:
		September 30, 2014					December 31, 2013
		Amortized			Percent		Amortized			Percent
		cost			of total		cost			of total
		($ in millions)
Geographic distribution
New England		$	508.6		4.8	%	$	528.5		5.1	%
Middle Atlantic		2,798.30			26.4		2,489.00			24.1
East North Central		462.4			4.4		519.9			5
West North Central		253			2.4		302.9			2.9
South Atlantic		1,944.60			18.4		1,949.50			18.9
East South Central		199.6			1.9		192.8			1.9
West South Central		1,003.60			9.5		830.3			8
Mountain		755.6			7.1		747.1			7.2
Pacific		2,631.10			24.7		2,722.50			26.5
International		40			0.4		45.2			0.4
Total		$	10,596.80		100	%	$	10,327.70		100	%
Property type distribution
Office		$	3,461.50		32.7	%	$	3,360.50		32.6	%
Retail		2,463.00			23.2		2,668.50			25.8
Industrial		1,942.20			18.3		1,766.20			17.1
Apartments		2,065.20			19.5		1,911.20			18.5
Hotel		337.1			3.2		333.1			3.2
Mixed use/other		327.8			3.1		288.2			2.8
Total		$	10,596.80		100	%	$	10,327.70		100	%
Our residential mortgage loan portfolio is composed of home equity mortgages with an amortized cost of $322.4 million and $394.9 million and first lien mortgages with an amortized cost of $883.7 million and $880.8 million as of September 30, 2014 and December 31, 2013, respectively. Our residential home equity mortgages are concentrated in the United States and are generally second lien mortgages comprised of closed-end loans and lines of credit. The majority of our first lien loans are concentrated in the Chilean market.
Mortgage Loan Credit Monitoring
Commercial Credit Risk Profile Based on Internal Rating
We actively monitor and manage our commercial mortgage loan portfolio. All commercial mortgage loans are analyzed regularly and substantially all are internally rated, based on a proprietary risk rating cash flow model, in order to monitor the financial quality of these assets. The model stresses expected cash flows at various levels and at different points in time depending on the durability of the income stream, which includes our assessment of factors such as location (macro and micro markets), tenant quality and lease expirations. Our internal rating analysis presents expected losses in terms of a Standard & Poor’s (“S&P”) bond equivalent rating. As the credit risk for commercial mortgage loans increases, we adjust our internal ratings downward with loans in the category “B+ and below” having the highest risk for credit loss. Internal ratings on commercial mortgage loans are updated at least annually and potentially more often for certain loans with material changes in collateral value or occupancy and for loans on an internal “watch list”.
Commercial mortgage loans that require more frequent and detailed attention than other loans in our portfolio are identified and placed on an internal “watch list”. Among the criteria that would indicate a potential problem are significant negative changes in ratios of loan to value or contract rents to debt service, major tenant vacancies or bankruptcies, borrower sponsorship problems, late payments, delinquent taxes and loan relief/restructuring requests.
The amortized cost of our commercial mortgage loan portfolio by credit risk, as determined by our internal rating system expressed in terms of an S&P bond equivalent rating, was as follows:
		September 30, 2014
		Brick and mortar			CTL			Total
		(in millions)
A- and above		$	8,762.30		$	179.2		$	8,941.50
BBB+ thru BBB-		1,211.80			195.2			1,407.00
BB+ thru BB-		181.9			—			181.9
B+ and below		64.7			1.7			66.4
Total		$	10,220.70		$	376.1		$	10,596.80
		December 31, 2013
		Brick and mortar			CTL			Total
		(in millions)
A- and above		$	8,091.90		$	194.5		$	8,286.40
BBB+ thru BBB-		1,463.70			250			1,713.70
BB+ thru BB-		155.4			0.1			155.5
B+ and below		170.1			2			172.1
Total		$	9,881.10		$	446.6		$	10,327.70
Residential Credit Risk Profile Based on Performance Status
Our residential mortgage loan portfolio is monitored based on performance of the loans. Monitoring on a residential mortgage loan increases when the loan is delinquent or earlier if there is an indication of impairment. We define non-performing residential mortgage loans as loans 90 days or greater delinquent or on non-accrual status.
The amortized cost of our performing and non-performing residential mortgage loans was as follows:
		September 30, 2014
		Home equity			First liens			Total
		(in millions)
Performing		$	307.3		$	868.1		$	1,175.40
Nonperforming		15.1			15.6			30.7
Total		$	322.4		$	883.7		$	1,206.10
		December 31, 2013
		Home equity			First liens			Total
		(in millions)
Performing		$	378.3		$	862.1		$	1,240.40
Nonperforming		16.6			18.7			35.3
Total		$	394.9		$	880.8		$	1,275.70
Non-Accrual Mortgage Loans
Commercial and residential mortgage loans are placed on non-accrual status if we have concern regarding the collectability of future payments or if a loan has matured without being paid off or extended. Factors considered may include conversations with the borrower, loss of major tenant, bankruptcy of borrower or major tenant, decreased property cash flow for commercial mortgage loans or number of days past due and other circumstances for residential mortgage loans. Based on an assessment as to the collectability of the principal, a determination is made to apply any payments received either against the principal or according to the contractual terms of the loan. When a loan is placed on nonaccrual status, the accrued unpaid interest receivable is reversed against interest income. Accrual of interest resumes after factors resulting in doubts about collectability have improved. Residential first lien mortgages in the Chilean market are carried on accrual for a longer period of delinquency than domestic loans, as assessment of collectability is based on the nature of the loans and collection practices in that market.
The amortized cost of mortgage loans on non-accrual status was as follows:
		September 30, 2014			December 31, 2013
		(in millions)
Commercial:
Brick and mortar		$	10.7		$	33.2
Residential:
Home equity		15.1			16.6
First liens		9.8			11.4
Total		$	35.6		$	61.2
The aging of our mortgage loans, based on amortized cost, was as follows:
		September 30, 2014
																		Recorded
																		investment
								90 days or										90 days or
		30-59 days			60-89 days			more past			Total past							more and
		past due			past due			due			due			Current		Total loans		accruing
		(in millions)
Commercial-brick and mortar		$	—		$	—		$	0.9		$	0.9		$	10,219.80	$	10,220.70	$	—
Commercial-CTL		—			—			—			—			376.1		376.1		—
Residential-home equity		2.5			2.4			2.2			7.1			315.3		322.4		—
Residential-first liens		23.8			4.8			14.9			43.5			840.2		883.7		5.8
Total		$	26.3		$	7.2		$	18		$	51.5		$	11,751.40	$	11,802.90	$	5.8
		December 31, 2013
																		Recorded
																		investment
								90 days or										90 days or
		30-59 days			60-89 days			more past			Total past							more and
		past due			past due			due			due			Current		Total loans		accruing
		(in millions)
Commercial-brick and mortar		$	—		$	—		$	16.7		$	16.7		$	9,864.40	$	9,881.10	$	—
Commercial-CTL		—			—			—			—			446.6		446.6		—
Residential-home equity		4.4			1			3			8.4			386.5		394.9		—
Residential-first liens		32.4			7.4			17.1			56.9			823.9		880.8		7.3
Total		$	36.8		$	8.4		$	36.8		$	82		$	11,521.40	$	11,603.40	$	7.3
Mortgage Loan Valuation Allowance
We establish a valuation allowance to provide for the risk of credit losses inherent in our portfolio. The valuation allowance includes loan specific reserves for loans that are deemed to be impaired as well as reserves for pools of loans with similar risk characteristics where a property risk or market specific risk has not been identified but for which we anticipate a loss may occur. Mortgage loans on real estate are considered impaired when, based on current information and events, it is probable that we will be unable to collect all amounts due according to contractual terms of the loan agreement. When we determine that a loan is impaired, a valuation allowance is established equal to the difference between the carrying amount of the mortgage loan and the estimated value reduced by the cost to sell. Estimated value is based on either the present value of the expected future cash flows discounted at the loan’s effective interest rate, the loan’s observable market price or fair value of the collateral. Subsequent changes in the estimated value are reflected in the valuation allowance. Amounts on loans deemed to be uncollectible are charged off and removed from the valuation allowance. The change in the valuation allowance provision is included in net realized capital gains (losses) on our consolidated statements of operations.
The valuation allowance is maintained at a level believed adequate by management to absorb estimated probable credit losses. Management’s periodic evaluation and assessment of the valuation allowance adequacy is based on known and inherent risks in the portfolio, adverse situations that may affect a borrower’s ability to repay, the estimated value of the underlying collateral, composition of the loan portfolio, portfolio delinquency information, underwriting standards, peer group information, current economic conditions, loss experience and other relevant factors. The evaluation of our impaired loan component is subjective, as it requires the estimation of timing and amount of future cash flows expected to be received on impaired loans.
We review our commercial mortgage loan portfolio and analyze the need for a valuation allowance for any loan that is delinquent for 60 days or more, in process of foreclosure, restructured, on the internal “watch list” or that currently has a valuation allowance. In addition to establishing allowance levels for specifically identified impaired commercial mortgage loans, management determines an allowance for all other loans in the portfolio for which historical experience and current economic conditions indicate certain losses exist. These loans are segregated by risk rating level with an estimated loss ratio applied against each risk rating level. The loss ratio is generally based upon historic loss experience for each risk rating level as adjusted for certain current environmental factors management believes to be relevant.
For our residential mortgage loan portfolio, we separate the loans into several homogeneous pools, each of which consist of loans of a similar nature including but not limited to loans similar in collateral, term and structure and loan purpose or type. We evaluate loan pools based on aggregated risk ratings, estimated specific loss potential in the different classes of credits, and historical loss experience by pool type. We adjust these quantitative factors for qualitative factors of present conditions. Qualitative factors include items such as economic and business conditions, changes in the portfolio, value of underlying collateral and concentrations. Residential mortgage loan pools exclude loans that have been restructured or impaired, as those loans are evaluated individually.
A rollforward of our valuation allowance and ending balances of the allowance and loan balance by basis of impairment method was as follows:
		For the three months ended September 30, 2014
		Commercial			Residential			Total
		(in millions)
Beginning balance		$	26.4		$	38.5		$	64.9
Provision		1.4			6.5			7.9
Charge-offs		—			(15.1		)	(15.1		)
Recoveries		—			0.3			0.3
Ending balance		$	27.8		$	30.2		$	58
		For the nine months ended September 30, 2014
		Commercial			Residential			Total
		(in millions)
Beginning balance		$	28.7		$	41.1		$	69.8
Provision		(0.6		)	7.3			6.7
Charge-offs		(0.3		)	(20.8		)	(21.1		)
Recoveries		—			2.7			2.7
Effect of exchange rates		—			(0.1		)	(0.1		)
Ending balance		$	27.8		$	30.2		$	58
Allowance ending balance by basis of impairment method:
Individually evaluated for impairment		$	3.1		$	9.4		$	12.5
Collectively evaluated for impairment		24.7			20.8			45.5
Allowance ending balance		$	27.8		$	30.2		$	58
Loan balance by basis of impairment method:
Individually evaluated for impairment		$	9.8		$	29.6		$	39.4
Collectively evaluated for impairment		10,587.00			1,176.50			11,763.50
Loan ending balance		$	10,596.80		$	1,206.10		$	11,802.90
		For the three months ended September 30, 2013
		Commercial			Residential			Total
		(in millions)
Beginning balance		$	47.7		$	47.2		$	94.9
Provision		0.7			1.3			2
Charge-offs		(6.2		)	(3.7		)	(9.9		)
Recoveries		0.2			0.7			0.9
Ending balance		$	42.4		$	45.5		$	87.9
		For the nine months ended September 30, 2013
		Commercial			Residential			Total
		(in millions)
Beginning balance		$	51.8		$	45.6		$	97.4
Provision		6.7			12.6			19.3
Charge-offs		(16.9		)	(15.0		)	(31.9		)
Recoveries		0.8			2.4			3.2
Effect of exchange rates		—			(0.1		)	(0.1		)
Ending balance		$	42.4		$	45.5		$	87.9
Allowance ending balance by basis of impairment method:
Individually evaluated for impairment		$	8.5		$	10.4		$	18.9
Collectively evaluated for impairment		33.9			35.1			69
Allowance ending balance		$	42.4		$	45.5		$	87.9
Loan balance by basis of impairment method:
Individually evaluated for impairment		$	30.7		$	34.7		$	65.4
Collectively evaluated for impairment		10,627.60			1,263.00			11,890.60
Loan ending balance		$	10,658.30		$	1,297.70		$	11,956.00
Impaired Mortgage Loans
Impaired mortgage loans are loans with a related specific valuation allowance, loans whose carrying amount has been reduced to the expected collectible amount because the impairment has been considered other than temporary or a loan modification has been classified as a troubled debt restructuring (“TDR”). Based on an assessment as to the collectability of the principal, a determination is made to apply any payments received either against the principal or according to the contractual terms of the loan. Our recorded investment in and unpaid principal balance of impaired loans along with the related loan specific allowance for losses, if any, and the average recorded investment and interest income recognized during the time the loans were impaired were as follows:
		September 30, 2014
					Unpaid
		Recorded			principal			Related
		investment			balance			allowance
		(in millions)
With no related allowance recorded:
Commercial-brick and mortar		$	0.9		$	2.2		$	—
Residential-first liens		4			4			—
With an allowance recorded:
Commercial-brick and mortar		9.8			9.8			3.1
Residential-home equity		17.6			19.2			8.5
Residential-first liens		8			7.9			0.9
Total:
Commercial		$	10.7		$	12		$	3.1
Residential		$	29.6		$	31.1		$	9.4
		December 31, 2013
					Unpaid
		Recorded			principal			Related
		investment			balance			allowance
		(in millions)
With no related allowance recorded:
Commercial-brick and mortar		$	21.5		$	32.7		$	—
Residential-first liens		4.6			4.6			—
With an allowance recorded:
Commercial-brick and mortar		4.4			4.4			2.4
Residential-home equity		19.5			19.7			9.2
Residential-first liens		8.9			7.8			1
Total:
Commercial		$	25.9		$	37.1		$	2.4
Residential		$	33		$	32.1		$	10.2
		For the three months ended						For the nine months ended
		September 30, 2014						September 30, 2014
		Average						Average
		recorded			Interest income			recorded			Interest income
		investment			recognized			investment			recognized
		(in millions)
With no related allowance recorded:
Commercial-brick and mortar		$	0.9		$	—		$	11.2		$	0.1
Residential-first liens		4.1			—			4.3			—
With an allowance recorded:
Commercial-brick and mortar		7.1			0.1			7.1			0.2
Residential-home equity		18			0.2			18.6			0.5
Residential-first liens		8			—			8.5			0.1
Total:
Commercial		$	8		$	0.1		$	18.3		$	0.3
Residential		$	30.1		$	0.2		$	31.4		$	0.6
		For the three months ended						For the nine months ended
		September 30, 2013						September 30, 2013
		Average						Average
		recorded			Interest income			recorded			Interest income
		investment			recognized			investment			recognized
		(in millions)
With no related allowance recorded:
Commercial-brick and mortar		$	6.4		$	0.1		$	16.2		$	0.2
Residential-first liens		6.2			—			7.9			—
With an allowance recorded:
Commercial-brick and mortar		28.4			0.1			17.5			0.2
Residential-home equity		20.2			0.4			20.3			0.8
Residential-first liens		9.3			—			9			0.1
Total:
Commercial		$	34.8		$	0.2		$	33.7		$	0.4
Residential		$	35.7		$	0.4		$	37.2		$	0.9
Mortgage Loan Modifications
Our commercial and residential mortgage loan portfolios include loans that have been modified. We assess loan modifications on a case-by-case basis to evaluate whether a TDR has occurred. The commercial mortgage loan TDRs were modified to delay or reduce principal payments and to increase, reduce or delay interest payments. For these TDR assessments, we have determined the loan rates are now considered below market based on current circumstances. The commercial mortgage loan modifications resulted in delayed cash receipts and a decrease in interest income. The residential mortgage loan TDRs include modifications of interest-only payment periods, delays in principal balloon payments, and interest rate reductions. Residential mortgage loan modifications resulted in delayed or decreased cash receipts and a decrease in interest income.
The following table includes information about outstanding loans that were modified and met the criteria of a TDR during the periods indicated. In addition, the table includes information for loans that were modified and met the criteria of a TDR within the past twelve months that were in payment default during the periods indicated:
		For the three months ended September 30, 2014
		TDRs					TDRs in payment default
		Number of		Recorded			Number of		Recorded
		contracts		investment			contracts		investment
				(in millions)					(in millions)
Commercial-brick and mortar		2		$	5.4		1		$	0.7
Residential-home equity		37		1.6			1		—
Total		39		$	7		2		$	0.7
		For the three months ended September 30, 2013
		TDRs					TDRs in payment default
		Number of		Recorded			Number of		Recorded
		contracts		investment			contracts		investment
				(in millions)					(in millions)
Residential-home equity		12		$	0.8		—		$	—
Residential-first liens		—		—			1		0.1
Total		12		$	0.8		1		$	0.1
		For the nine months ended September 30, 2014
		TDRs					TDRs in payment default
		Number of		Recorded			Number of		Recorded
		contracts		investment			contracts		investment
				(in millions)					(in millions)
Commercial-brick and mortar		4		$	10.5		1		$	0.7
Residential-home equity		75		2.9			3		—
Residential-first liens		1		0.1			—		—
Total		80		$	13.5		4		$	0.7
		For the nine months ended September 30, 2013
		TDRs					TDRs in payment default
		Number of		Recorded			Number of		Recorded
		contracts		investment			contracts		investment
				(in millions)					(in millions)
Commercial-brick and mortar		2		$	0.9		—		$	—
Residential-home equity		60		3.1			13		—
Residential-first liens		3		0.6			3		0.8
Total		65		$	4.6		16		$	0.8
Commercial mortgage loans that have been designated as a TDR have been previously reserved in the mortgage loan valuation allowance to the estimated fair value of the underlying collateral reduced by the cost to sell.
Residential mortgage loans that have been designated as a TDR are specifically reserved for in the mortgage loan valuation allowance if losses result from the modification. Residential mortgage loans that have defaulted or have been discharged through bankruptcy are reduced to the expected collectible amount.
Securities Posted as Collateral
We posted $1,344.7 million in fixed maturities, available-for-sale securities at September 30, 2014, to satisfy collateral requirements primarily associated with a reinsurance arrangement, our derivative credit support annex (collateral) agreements, Futures Commission Merchant (“FCM”) agreements, a lending arrangement and our obligation under funding agreements with the Federal Home Loan Bank of Des Moines (“FHLB Des Moines”). In addition, we posted $2,074.3 million in commercial mortgage loans and home equity mortgages as of September 30, 2014, to satisfy collateral requirements associated with our obligation under funding agreements with the FHLB Des Moines. Since we did not relinquish ownership rights on these instruments, they are reported as fixed maturities, available-for-sale and mortgage loans, respectively, on our consolidated statements of financial position. Of the securities posted as collateral, $170.9 million can be sold or repledged by the secured party.
Balance Sheet Offsetting
We have financial instruments that are subject to master netting agreements or similar agreements. Financial assets subject to master netting agreements or similar agreements were as follows:
					Gross amounts not offset in the
					Statement of Financial Position
		Gross amount
		of recognized			Financial			Collateral
		assets (1)			instruments (2)			received			Net amount
		(in millions)
September 30, 2014
Derivative assets		$	558.7		$	(451.0	)	$	(89.8	)	$	17.9
Reverse repurchase agreements		50.8			—			(50.8		)	—
Total		$	609.5		$	(451.0	)	$	(140.6	)	$	17.9
December 31, 2013
Derivative assets		$	664.9		$	(581.5	)	$	(82.1	)	$	1.3
Reverse repurchase agreements		51.8			—			(51.8		)	—
Total		$	716.7		$	(581.5	)	$	(133.9	)	$	1.3
(1)     The gross amount of recognized derivative and reverse repurchase agreement assets are reported with other investments and cash and cash equivalents on the consolidated statements of financial position. The above excludes $0.0 million and $0.2 million of derivative assets as of September 30, 2014 and December 31, 2013, respectively, that are not subject to master netting agreements or similar agreements. The gross amounts of derivative and reverse repurchase agreement assets are not netted against offsetting liabilities for presentation on the consolidated statements of financial position.
(2)     Represents amount of offsetting derivative liabilities that are subject to an enforceable master netting agreement or similar agreement that are not netted against the gross derivative assets for presentation on the consolidated statements of financial position.
Financial liabilities subject to master netting agreements or similar agreements were as follows:
					Statement of Financial Position
		Gross amount
		of recognized			Financial			Collateral
		liabilities (1)			instruments (2)			pledged			Net amount
		(in millions)
September 30, 2014
Derivative liabilities		$	789.3		$	(451.0	)	$	(239.9	)	$	98.4
December 31, 2013
Derivative liabilities		$	1,022.00		$	(581.5	)	$	(362.1	)	$	78.4
(1)     The gross amount of recognized derivative liabilities are reported with other liabilities on the consolidated statements of financial position. The above excludes $341.4 million and $226.7 million of derivative liabilities as of September 30, 2014 and December 31, 2013, respectively, which are primarily embedded derivatives that are not subject to master netting agreements or similar agreements. The gross amounts of derivative liabilities are not netted against offsetting assets for presentation on the consolidated statements of financial position.
(2)     Represents amount of offsetting derivative assets that are subject to an enforceable master netting agreement or similar agreement that are not netted against the gross derivative liabilities for presentation on the consolidated statements of financial position.
The financial instruments that are subject to master netting agreements or similar agreements include right of setoff provisions. Derivative instruments include provisions to setoff positions covered under the agreements with the same counterparties and provisions to setoff positions outside of the agreements with the same counterparties in the event of default by one of the parties. Derivative instruments also include collateral provisions. Collateral received and pledged is generally settled daily with each counterparty. See Note 4, Derivative Financial Instruments, for further details.
Repurchase and reverse repurchase agreements include provisions to setoff other repurchase and reverse repurchase balances with the same counterparty. Repurchase and reverse repurchase agreements also include collateral provisions with the counterparties. For reverse repurchase agreements we require the counterparties to pledge collateral with a value greater than the amount of cash transferred. We have the right but do not sell or repledge collateral received in reverse repurchase agreements. Repurchase agreements are structured as secured borrowings for all counterparties. We pledge fixed maturities available-for-sale, which the counterparties have the right to sell or repledge. Interest incurred on repurchase agreements is reported as part of operating expense on the consolidated statements of operations. Net proceeds related to repurchase agreements are reported as a component of financing activities on the consolidated statements of cash flows. We did not have any outstanding repurchase agreements as of September 30, 2014 and December 31, 2013.

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2014
Derivative Financial Instruments	'
Derivative Financial Instruments	'
	4.  Derivative Financial Instruments
	Derivatives are generally used to hedge or reduce exposure to market risks associated with assets held or expected to be purchased or sold and liabilities incurred or expected to be incurred. Derivatives are used to change the characteristics of our asset/liability mix consistent with our risk management activities. Derivatives are also used in asset replication strategies.
	Types of Derivative Instruments
	Interest Rate Contracts
	Interest rate risk is the risk we will incur economic losses due to adverse changes in interest rates. Sources of interest rate risk include the difference between the maturity and interest rate changes of assets with the liabilities they support, timing differences between the pricing of liabilities and the purchase or procurement of assets and changing cash flow profiles from original projections due to prepayment options embedded within asset and liability contracts. We use various derivatives to manage our exposure to fluctuations in interest rates.
	Interest rate swaps are contracts in which we agree with other parties to exchange, at specified intervals, the difference between fixed rate and floating rate interest amounts based upon designated market rates or rate indices and an agreed upon notional principal amount. Generally, no cash is exchanged at the outset of the contract and no principal payments are made by any party. Cash is paid or received based on the terms of the swap. We use interest rate swaps primarily to more closely match the interest rate characteristics of assets and liabilities and to mitigate the risks arising from timing mismatches between assets and liabilities (including duration mismatches). We also use interest rate swaps to hedge against changes in the value of assets we anticipate acquiring and other anticipated transactions and commitments. Interest rate swaps are used to hedge against changes in the value of the guaranteed minimum withdrawal benefit (“GMWB”) liability. The GMWB rider on our variable annuity products provides for guaranteed minimum withdrawal benefits regardless of the actual performance of various equity and/or fixed income funds available with the product.
	Interest rate options, including interest rate caps and interest rate floors, which can be combined to form interest rate collars, are contracts that entitle the purchaser to pay or receive the amounts, if any, by which a specified market rate exceeds a cap strike interest rate, or falls below a floor strike interest rate, respectively, at specified dates. We use interest rate collars to manage interest rate risk related to guaranteed minimum interest rate liabilities in our individual annuities contracts and lapse risk associated with higher interest rates.
	A swaption is an option to enter into an interest rate swap at a future date. We purchase swaptions to offset or modify existing exposures. Swaptions provide us the benefit of the agreed-upon strike rate if the market rates for liabilities are higher, with the flexibility to enter into the current market rate swap if the market rates for liabilities are lower. Swaptions not only hedge against the downside risk, but also allow us to take advantage of any upside benefits.
	In exchange-traded futures transactions, we agree to purchase or sell a specified number of contracts, the values of which are determined by the values of designated classes of securities, and to post variation margin on a daily basis in an amount equal to the difference in the daily market values of those contracts. We enter into exchange-traded futures with regulated futures commissions merchants who are members of a trading exchange. We have used exchange-traded futures to reduce market risks from changes in interest rates and to alter mismatches between the assets in a portfolio and the liabilities supported by those assets.
	Foreign Exchange Contracts
	Foreign currency risk is the risk we will incur economic losses due to adverse fluctuations in foreign currency exchange rates. This risk arises from foreign currency-denominated funding agreements we issue, foreign currency-denominated fixed maturities we invest in and the financial results of our international operations, including acquisition and divestiture activity. We use various derivatives to manage our exposure to fluctuations in foreign currency exchange rates.
	Currency swaps are contracts in which we agree with other parties to exchange, at specified intervals, a series of principal and interest payments in one currency for that of another currency. Generally, the principal amount of each currency is exchanged at the beginning and termination of the currency swap by each party. The interest payments are primarily fixed-to-fixed rate; however, they may also be fixed-to-floating rate or floating-to-fixed rate. These transactions are entered into pursuant to master agreements that provide for a single net payment to be made by one counterparty for payments made in the same currency at each due date. We use currency swaps to reduce market risks from changes in currency exchange rates with respect to investments or liabilities denominated in foreign currencies that we either hold or intend to acquire or sell.
	Currency forwards are contracts in which we agree with other parties to deliver or receive a specified amount of an identified currency at a specified future date. Typically, the price is agreed upon at the time of the contract and payment for such a contract is made at the specified future date. We use currency forwards to reduce market risks from changes in currency exchange rates with respect to investments or liabilities denominated in foreign currencies that we either hold or intend to acquire or sell and to hedge the currency risk associated with a business combination. We have also used currency forwards to hedge the currency risk associated with net investments in foreign operations. We did not use any currency forwards during 2014 or 2013 to hedge our net investment in foreign operations.
	Equity Contracts
	Equity risk is the risk that we will incur economic losses due to adverse fluctuations in common stock. We use various derivatives to manage our exposure to equity risk, which arises from products in which the interest we credit is tied to an external equity index as well as products subject to minimum contractual guarantees.
	We purchase equity call spreads to hedge the equity participation rates promised to contractholders in conjunction with our fixed deferred annuity and universal life products that credit interest based on changes in an external equity index. We use exchange-traded futures and equity put options to hedge against changes in the value of the GMWB liability related to the GMWB rider on our variable annuity product, as previously explained. The premium associated with certain options is paid quarterly over the life of the option contract.
	Credit Contracts
	Credit risk relates to the uncertainty associated with the continued ability of a given obligor to make timely payments of principal and interest. We use credit default swaps to enhance the return on our investment portfolio by providing comparable exposure to fixed income securities that might not be available in the primary market. They are also used to hedge credit exposures in our investment portfolio. Credit derivatives are used to sell or buy credit protection on an identified name or names on an unfunded or synthetic basis in return for receiving or paying a quarterly premium. The premium generally corresponds to a referenced name’s credit spread at the time the agreement is executed. In cases where we sell protection, we also buy a quality cash bond to match against the credit default swap, thereby entering into a synthetic transaction replicating a cash security. When selling protection, if there is an event of default by the referenced name, as defined by the agreement, we are obligated to pay the counterparty the referenced amount of the contract and receive in return the referenced security in a principal amount equal to the notional value of the credit default swap.
	Total return swaps are contracts in which we agree with other parties to exchange, at specified intervals, an amount determined by the difference between the previous price and the current price of a reference asset based upon an agreed upon notional principal amount plus an additional amount determined by the financing spread. We currently use futures traded on an exchange (“exchange-traded”) and total return swaps referencing equity indices to hedge our portfolio from potential credit losses related to systemic events.
	Other Contracts
	Embedded Derivatives. We purchase or issue certain financial instruments or products that contain a derivative instrument that is embedded in the financial instrument or product. When it is determined that the embedded derivative possesses economic characteristics that are not clearly or closely related to the economic characteristics of the host contract and a separate instrument with the same terms would qualify as a derivative instrument, the embedded derivative is bifurcated from the host instrument for measurement purposes. The embedded derivative, which is reported with the host instrument in the consolidated statements of financial position, is carried at fair value.
	We have investment-type insurance contracts in which the return is tied to a leveraged inflation index. In addition, we had an investment-type insurance contract in which the return was tied to an external equity index. We economically hedge the risk associated with these investment-type insurance contracts.
	We offer group annuity contracts that have guaranteed separate accounts as an investment option. We also offer funds with embedded fixed-rate guarantees as investment options in our defined contribution plans in Hong Kong.
	We have structured investment relationships with trusts we have determined to be VIEs, which are consolidated in our financial statements. The notes issued by these trusts include obligations to deliver an underlying security to residual interest holders and the obligations contain an embedded derivative of the forecasted transaction to deliver the underlying security.
	We have fixed deferred annuities and universal life contracts that credit interest based on changes in an external equity index. We also have certain variable annuity products with a GMWB rider, which allows the customer to make withdrawals of a specified annual amount, either for a fixed number of years or for the lifetime of the customer, even if the account value is fully exhausted. Declines in the equity markets may increase our exposure to benefits under contracts with the GMWB. We economically hedge the exposure in these contracts, as previously explained.
	Exposure
	Our risk of loss is typically limited to the fair value of our derivative instruments and not to the notional or contractual amounts of these derivatives. We are also exposed to credit losses in the event of nonperformance of the counterparties. Our current credit exposure is limited to the value of derivatives that have become favorable to us. This credit risk is minimized by purchasing such agreements from financial institutions with high credit ratings and by establishing and monitoring exposure limits. We also utilize various credit enhancements, including collateral and credit triggers to reduce the credit exposure to our derivative instruments.
	Derivatives may be exchange-traded or they may be privately negotiated contracts, which are usually referred to as over-the-counter (“OTC”) derivatives. Certain of our OTC derivatives are cleared and settled through central clearing counterparties (“OTC cleared”), while others are bilateral contracts between two counterparties (“bilateral OTC”). Our derivative transactions are generally documented under International Swaps and Derivatives Association, Inc. (“ISDA”) Master Agreements. Management believes that such agreements provide for legally enforceable set-off and close-out netting of exposures to specific counterparties. Under such agreements, in connection with an early termination of a transaction, we are permitted to set off our receivable from a counterparty against our payables to the same counterparty arising out of all included transactions. For reporting purposes, we do not offset fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral against fair value amounts recognized for derivative instruments executed with the same counterparties under master netting agreements.
	We posted $276.6 million and $393.1 million in cash and securities under collateral arrangements as of September 30, 2014 and December 31, 2013, respectively, to satisfy collateral requirements associated with our derivative credit support agreements and FCM agreements. These amounts include initial margin requirements.
	Certain of our derivative instruments contain provisions that require us to maintain an investment grade rating from each of the major credit rating agencies on our debt. If the ratings on our debt were to fall below investment grade, it would be in violation of these provisions and the counterparties to the derivative instruments could request immediate payment or demand immediate and ongoing full overnight collateralization on derivative instruments in net liability positions. The aggregate fair value, inclusive of accrued interest, of all derivative instruments with credit-risk-related contingent features that were in a liability position without regard to netting under derivative credit support annex agreements as of September 30, 2014 and December 31, 2013, was $676.5 million and $1,042.9 million, respectively. Cleared derivatives have contingent features that require us to post excess margin as required by the FCM. The terms surrounding excess margin vary by FCM agreement. With respect to derivatives containing collateral triggers, we posted collateral and initial margin of $276.6 million and $393.1 million as of September 30, 2014 and December 31, 2013, respectively, in the normal course of business, which reflects netting under derivative agreements. If the credit-risk-related contingent features underlying these agreements were triggered on September 30, 2014, we would be required to post an additional $65.3 million of collateral to our counterparties.
	As of September 30, 2014 and December 31, 2013, we had received $72.4 million and $32.5 million, respectively, of cash collateral associated with our derivative credit support annex agreements and FCM agreements, for which we recorded a corresponding liability reflecting our obligation to return the collateral.
	Notional amounts are used to express the extent of our involvement in derivative transactions and represent a standard measurement of the volume of our derivative activity. Notional amounts represent those amounts used to calculate contractual flows to be exchanged and are not paid or received, except for contracts such as currency swaps. Credit exposure represents the gross amount owed to us under derivative contracts as of the valuation date. The notional amounts and credit exposure of our derivative financial instruments by type were as follows:
		September 30, 2014			December 31, 2013
		(in millions)
	Notional amounts of derivative instruments
	Interest rate contracts:
	Interest rate swaps	$	18,747.50		$	20,570.80
	Interest rate options	4,900.00			4,100.00
	Swaptions	260			325
	Interest rate futures	139.5			92.5
	Foreign exchange contracts:
	Currency swaps	2,034.50			2,367.50
	Currency forwards	264			247.4
	Equity contracts:
	Equity options	2,967.80			2,010.40
	Equity futures	422.5			273.3
	Credit contracts:
	Credit default swaps	1,280.60			1,153.20
	Total return swaps	70			90
	Futures	28.1			9.1
	Other contracts:
	Embedded derivative financial instruments	9,058.60			7,601.10
	Total notional amounts at end of period	$	40,173.10		$	38,840.30
	Credit exposure of derivative instruments
	Interest rate contracts:
	Interest rate swaps	$	424.2		$	435.5
	Interest rate options	38.2			42.5
	Swaptions	0.1			1
	Foreign exchange contracts:
	Currency swaps	93.6			200.9
	Currency forwards	—			0.6
	Equity contracts:
	Equity options	20.4			30
Credit contracts:
Credit default swaps	12.5			9.5
Total return swaps	0.3			0.1
Total gross credit exposure	589.3			720.1
Less: collateral received	108.9			115.9
Net credit exposure	$	480.4		$	604.2
The fair value of our derivative instruments classified as assets and liabilities was as follows:
	Derivative assets (1)						Derivative liabilities (2)
	September 30, 2014			December 31, 2013			September 30, 2014			December 31, 2013
	(in millions)
Derivatives designated as hedging instruments
Interest rate contracts	$	0.5		$	0.1		$	201.8		$	285.4
Foreign exchange contracts	70.2			121.6			43.1			51.2
Total derivatives designated as hedging instruments	$	70.7		$	121.7		$	244.9		$	336.6
Derivatives not designated as hedging instruments
Interest rate contracts	$	425.6		$	452.2		$	327.9		$	489.6
Foreign exchange contracts	29.2			51.6			39.2			17.9
Equity contracts	20.4			30			148.1			145
Credit contracts	12.8			9.6			34.5			35.5
Other contracts	—			—			336.1			224.1
Total derivatives not designated as hedging instruments	488			543.4			885.8			912.1
Total derivative instruments	$	558.7		$	665.1		$	1,130.70		$	1,248.70
(1)     The fair value of derivative assets is reported with other investments on the consolidated statements of financial position.
(2)     The fair value of derivative liabilities is reported with other liabilities on the consolidated statements of financial position, with the exception of certain embedded derivative liabilities. Embedded derivative liabilities with a fair value of $94.1 million and $6.9 million as of September 30, 2014 and December 31, 2013, respectively, are reported with contractholder funds on the consolidated statements of financial position.
Credit Derivatives Sold
When we sell credit protection, we are exposed to the underlying credit risk similar to purchasing a fixed maturity security instrument. The majority of our credit derivative contracts sold reference a single name or reference security (referred to as “single name credit default swaps”). The remainder of our credit derivatives reference either a basket or index of securities. These instruments are either referenced in an over-the-counter credit derivative transaction, or embedded within an investment structure that has been fully consolidated into our financial statements.
These credit derivative transactions are subject to events of default defined within the terms of the contract, which normally consist of bankruptcy, failure to pay, or modified restructuring of the reference entity and/or issue. If a default event occurs for a reference name or security, we are obligated to pay the counterparty an amount equal to the notional amount of the credit derivative transaction. As a result, our maximum future payment is equal to the notional amount of the credit derivative. In certain cases, we also have purchased credit protection with identical underlyings to certain of our sold protection transactions. The effect of this purchased protection would reduce our total maximum future payments by $34.9 million as of September 30, 2014 and $44.9 million as of December 31, 2013. These purchased credit derivative transactions had a net asset (liability) fair value of $(0.4) million as of September 30, 2014 and $(0.5) million as of December 31, 2013. In certain circumstances, our potential loss could also be reduced by any amount recovered in the default proceedings of the underlying credit name.
We purchased an investment structure with embedded credit features that is fully consolidated into our financial statements. This consolidation results in recognition of the underlying credit derivatives and collateral within the structure, typically high quality fixed maturities that are owned by a special purpose vehicle. These credit derivatives reference several names in a basket structure. In the event of default, the collateral within the structure would typically be liquidated to pay the claims of the credit derivative counterparty.
The following tables show our credit default swap protection sold by types of contract, types of referenced/underlying asset class and external agency rating for the underlying reference security. The maximum future payments are undiscounted and have not been reduced by the effect of any offsetting transactions, collateral or recourse features described above.
	September 30, 2014
										Weighted
							Maximum			average
	Notional			Fair			future			expected life
	amount			value			payments			(in years)
	(in millions)
Single name credit default swaps
Corporate debt
AAA	$	30		$	1		$	30		4.5
AA	99			1.8			99			3.7
A	294.5			4.4			294.5			3.5
BBB	385			4.6			385			3.9
BB	15			(0.4		)	15			3.7
Total single name credit default swaps	823.5			11.4			823.5			3.7
Basket and index credit default swaps
Corporate debt
Near default (1)	100.4			(22.5		)	100.4			2.5
Government/municipalities
AA	30			(2.3		)	30			3
Structured finance
BBB	25			(0.3		)	25			2.8
Total basket and index credit default swaps	155.4			(25.1		)	155.4			2.6
Total credit default swap protection sold	$	978.9		$	(13.7	)	$	978.9		3.5
	December 31, 2013
										Weighted
							Maximum			average
	Notional			Fair			future			expected life
	amount			value			payments			(in years)
	(in millions)
Single name credit default swaps
Corporate debt
AAA	$	10		$	0.3		$	10		4.7
AA	84			1.8			84			4
A	294.5			4.2			294.5			4
BBB	265			(1.2		)	265			3.9
Total single name credit default swaps	653.5			5.1			653.5			4
Basket and index credit default swaps
Corporate debt
Near default (1)	110.4			(19.9		)	110.4			3.2
Government/municipalities
AA	30			(3.5		)	30			3.7
Structured finance
BBB	25			(0.9		)	25			3.5
Total basket and index credit default swaps	165.4			(24.3		)	165.4			3.4
Total credit default swap protection sold	$	818.9		$	(19.2	)	$	818.9		3.9
(1)         Includes $78.0 million and $88.0 million as of September 30, 2014 and December 31, 2013, respectively, notional of derivatives in consolidated collateralized private investment vehicle VIEs where the credit risk is borne by third-party investors.
We also have invested in fixed maturities classified as available-for-sale that contain credit default swaps that do not require bifurcation and fixed maturities classified as trading that contain credit default swaps. These securities are subject to the credit risk of the issuer, normally a special purpose vehicle, which consists of the underlying credit default swaps and high quality fixed maturities that serve as collateral. A default event occurs if the cumulative losses exceed a specified attachment point, which is typically not the first loss of the portfolio. If a default event occurs that exceeds the specified attachment point, our investment may not be fully returned. We would have no future potential payments under these investments. The following tables show, by the types of referenced/underlying asset class and external rating, our fixed maturities with embedded credit derivatives.
	September 30, 2014
							Weighted
							average
	Amortized			Carrying			expected life
	cost			value			(in years)
	(in millions)
Corporate debt
A	$	23.8		$	23.8		2.3
Total corporate debt	23.8			23.8			2.3
Structured finance
A	49.8			49.8			2.1
BB	5.8			5.8			2.7
CCC	9.4			9.4			4.3
Total structured finance	65			65			2.5
Total fixed maturities with credit derivatives	$	88.8		$	88.8		2.4
	December 31, 2013
							Weighted
							average
	Amortized			Carrying			expected life
	cost			value			(in years)
	(in millions)
Corporate debt
BBB	$	23.4		$	23.4		3
Total corporate debt	23.4			23.4			3
Structured finance
A	18.1			16.7			4.8
BB	5.5			5.5			3.3
B	4.1			4.1			3.1
CCC	23.5			23.5			4.8
Total structured finance	51.2			49.8			4.5
Total fixed maturities with credit derivatives	$	74.6		$	73.2		4
Fair Value Hedges
We use fixed-to-floating rate interest rate swaps to more closely align the interest rate characteristics of certain assets and liabilities. In general, these swaps are used in asset and liability management to modify duration, which is a measure of sensitivity to interest rate changes.
We enter into currency exchange swap agreements to convert certain foreign denominated assets and liabilities into U.S. dollar floating-rate denominated instruments to eliminate the exposure to future currency volatility on those items.
The net interest effect of interest rate swap and currency swap transactions for derivatives in fair value hedges is recorded as an adjustment to income or expense of the underlying hedged item in our consolidated statements of operations.
Hedge effectiveness testing for fair value relationships is performed utilizing a regression analysis approach for both prospective and retrospective evaluations. This regression analysis will consider multiple data points for the assessment that the hedge continues to be highly effective in achieving offsetting changes in fair value. In certain periods, the comparison of the change in value of the derivative and the change in the value of the hedged item may not be offsetting at a specific period in time due to small movements in value. However, any amounts recorded as fair value hedges have shown to be highly effective in achieving offsetting changes in fair value both for present and future periods.
The following table shows the effect of derivatives in fair value hedging relationships and the related hedged items on the consolidated statements of operations. All gains or losses on derivatives were included in the assessment of hedge effectiveness.
									Amount of gain (loss)
	Amount of gain (loss)								recognized in net income on
	recognized in net income on								related hedged item for the
	derivatives for the three months								three months ended
Derivatives in fair value hedging	ended September 30, (1)						Hedged items in fair value		September 30, (1)
relationships	2014			2013			hedging relationships		2014			2013
	(in millions)								(in millions)
Interest rate contracts	$	18.5		$	14.6		Fixed maturities, available- for-sale		$	(18.3	)	$	(14.1	)
Interest rate contracts	(2.4		)	1.2			Investment-type insurance contracts		2.4			(1.5		)
Foreign exchange contracts	3			(1.1		)	Fixed maturities, available- for-sale		(3.1		)	1.2
Foreign exchange contracts	—			35			Investment-type insurance contracts		—			(34.9		)
Total	$	19.1		$	49.7		Total		$	(19.0	)	$	(49.3	)
									Amount of gain (loss)
	Amount of gain (loss)								recognized in net income on
	recognized in net income on								related hedged item for the
	derivatives for the nine months								for the nine months
Derivatives in fair value hedging	ended September 30, (1)						Hedged items in fair value		ended September 30, (1)
relationships	2014			2013			hedging relationships		2014			2013
	(in millions)								(in millions)
Interest rate contracts	$	27.2		$	110.9		Fixed maturities, available- for-sale		$	(28.4	)	$	(105.4	)
Interest rate contracts	0.2			1.2			Investment-type insurance contracts		(0.1		)	(1.5		)
Foreign exchange contracts	3.8			0.2			Fixed maturities, available- for-sale		(3.8		)	—
Foreign exchange contracts	0.2			(39.1		)	Investment-type insurance contracts		(0.2		)	38.7
Total	$	31.4		$	73.2		Total		$	(32.5	)	$	(68.2	)
(1)         The gain (loss) on both derivatives and hedged items in fair value relationships is reported in net realized capital gains (losses) on the consolidated statements of operations. The net amount represents the ineffective portion of our fair value hedges.
The following table shows the periodic settlements on interest rate contracts and foreign exchange contracts in fair value hedging relationships.
	Amount of gain (loss) for the three						Amount of gain (loss) for the
	months ended September 30,						nine months ended September 30,
Hedged item	2014			2013			2014			2013
	(in millions)
Fixed maturities, available-for-sale (1)	$	(22.2	)	$	(30.9	)	$	(71.5	)	$	(92.1	)
Investment-type insurance contracts (2)	1			9.9			3.4			29.2
(1)         Reported in net investment income on the consolidated statements of operations.
(2)         Reported in benefits, claims and settlement expenses on the consolidated statements of operations.
Cash Flow Hedges
We utilize floating-to-fixed rate interest rate swaps to eliminate the variability in cash flows of recognized financial assets and liabilities and forecasted transactions.
We enter into currency exchange swap agreements to convert both principal and interest payments of certain foreign denominated assets and liabilities into U.S. dollar denominated fixed-rate instruments to eliminate the exposure to future currency volatility on those items.
The net interest effect of interest rate swap and currency swap transactions for derivatives in cash flow hedges is recorded as an adjustment to income or expense of the underlying hedged item in our consolidated statements of operations.
The maximum length of time we are hedging our exposure to the variability in future cash flows for forecasted transactions, excluding those related to the payments of variable interest on existing financial assets and liabilities, is 5.7 years. At September 30, 2014, we had $63.2 million of net gains reported in AOCI on the consolidated statements of financial position related to active hedges of forecasted transactions. If a hedged forecasted transaction is no longer probable of occurring, cash flow hedge accounting is discontinued. If it is probable that the hedged forecasted transaction will not occur, the deferred gain or loss is immediately reclassified from AOCI into net income. We reclassified $0.0 million and $0.2 million from AOCI into net realized capital gains (losses) as a result of the determination that hedged cash flows were probable of not occurring during the nine months ended September 30, 2014 and 2013, respectively.
The following table shows the effect of derivatives in cash flow hedging relationships on the consolidated statements of operations and consolidated statements of financial position. All gains or losses on derivatives were included in the assessment of hedge effectiveness.
			Amount of gain (loss)								Amount of gain (loss)
			recognized in AOCI on								reclassified from AOCI on
			derivatives (effective portion)						Location of gain (loss)		derivatives (effective portion)
Derivatives in cash			for the three months ended						reclassified from AOCI		for the three months ended
flow hedging			September 30,						into net income		September 30,
relationships	Related hedged item		2014			2013			(effective portion)		2014			2013
			(in millions)								(in millions)
Interest rate contracts	Fixed maturities, available-for-sale		$	8.8		$	(10.2	)	Net investment income		$	3.5		$	3
Interest rate contracts	Investment-type insurance contracts		0.2			0.6			Benefits, claims and settlement expenses		—			—
Interest rate contracts	Debt		—			—			Operating expense		(1.9		)	(1.7		)
Foreign exchange contracts	Fixed maturities, available-for-sale		44.6			(44.7		)	Net realized capital gains (losses)		0.2			(3.2		)
Foreign exchange contracts	Investment-type insurance contracts		1.3			2.8			Benefits, claims and settlement expenses		—			—
Total			$	54.9		$	(51.5	)	Total		$	1.8		$	(1.9	)
			Amount of gain (loss)								Amount of gain (loss)
			recognized in AOCI on								reclassified from AOCI on
			derivatives (effective portion)						Location of gain (loss)		derivatives (effective portion)
Derivatives in cash			for the nine months ended						reclassified from AOCI		for the nine months ended
flow hedging			September 30,						into net income		September 30,
relationships	Related hedged item		2014			2013			(effective portion)		2014			2013
			(in millions)								(in millions)
Interest rate contracts	Fixed maturities, available-for-sale		$	10.8		$	(51.4	)	Net investment income		$	10.1		$	8.6
Interest rate contracts	Investment-type insurance contracts		2.6			1.7			Benefits, claims and settlement expenses		—			—
Interest rate contracts	Debt		—			—			Operating expense		(5.5		)	(4.9		)
Foreign exchange contracts	Fixed maturities, available-for-sale		44.4			(3.1		)	Net realized capital losses		(10.9		)	(5.3		)
Foreign exchange contracts	Investment-type insurance contracts		9.8			2.2			Benefits, claims and settlement expenses		—			—
Total			$	67.6		$	(50.6	)	Total		$	(6.3	)	$	(1.6	)
The following table shows the periodic settlements on interest rate contracts and foreign exchange contracts in cash flow hedging relationships.
	Amount of gain (loss) for the						Amount of gain (loss) for the
	three months ended September 30,						nine months ended September 30,
Hedged item	2014			2013			2014			2013
	(in millions)
Fixed maturities, available-for-sale (1)	$	1.1		$	1.9		$	3.9		$	6.2
Investment-type insurance contracts (2)	(2.6		)	(2.7		)	(8.4		)	(8.2		)
(1)      Reported in net investment income on the consolidated statements of operations.
(2)      Reported in benefits, claims and settlement expenses on the consolidated statements of operations.
The ineffective portion of our cash flow hedges is reported in net realized capital gains (losses) on the consolidated statements of operations. The net gain (loss) resulting from the ineffective portion of foreign currency contracts in cash flow hedging relationships was $0.1 million and $0.1 million for the three months ended September 30, 2014 and 2013, respectively. The net gain (loss) resulting from the ineffective portion of foreign currency contracts in cash flow hedging relationships was $0.0 million and $0.5 million for the nine months ended September 30, 2014 and 2013, respectively.
We expect to reclassify net gains of $1.7 million from AOCI into net income in the next 12 months, which includes both net deferred gains on discontinued hedges and net losses on periodic settlements of active hedges. Actual amounts may vary from this amount as a result of market conditions.
Derivatives Not Designated as Hedging Instruments
Our use of futures, certain swaptions and swaps, collars, options and forwards are effective from an economic standpoint, but they have not been designated as hedges for financial reporting purposes. As such, periodic changes in the market value of these instruments, which includes mark-to-market gains and losses as well as periodic and final settlements, primarily flow directly into net realized capital gains (losses) on the consolidated statements of operations.
The following table shows the effect of derivatives not designated as hedging instruments, including fair value changes of embedded derivatives that have been bifurcated from the host contract, on the consolidated statements of operations.
	Amount of gain (loss) recognized in						Amount of gain (loss) recognized in
	net income on derivatives for the						net income on derivatives for the
	three months ended September 30,						nine months ended September 30,
Derivatives not designated as hedging instruments	2014			2013			2014			2013
	(in millions)
Interest rate contracts	$	38.3		$	(20.0	)	$	134.7		$	(112.1	)
Foreign exchange contracts	(43.7		)	14.9			(56.6		)	3.1
Equity contracts	37.7			(49.0		)	0.1			(120.5		)
Credit contracts	(21.7		)	10.4			(10.8		)	32.8
Other contracts	(62.0		)	18.4			(108.5		)	117.9
Total	$	(51.4	)	$	(25.3	)	$	(41.1	)	$	(78.8	)

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
Income Taxes	'
Income Taxes	'
	5.  Income Taxes
	The effective income tax rate for the three months ended September 30, 2014, was higher than the U.S. corporate income tax rate of 35% (“U.S. statutory rate”) primarily due to an increase in net deferred tax liabilities resulting from the third quarter 2014 enactment of tax legislation in Chile, partially offset by income tax deductions allowed for corporate dividends received, the presentation of taxes on our share of earnings generated from equity method investments reflected in net investment income and lower tax rates of foreign jurisdictions.
	The effective income tax rate for the three months ended September 30, 2013, was lower than the U.S. statutory rate primarily due to income tax deductions allowed for corporate dividends received, the presentation of taxes on our share of earnings generated from equity method investments reflected in net investment income and lower tax rates of foreign jurisdictions.
	The effective income tax rate for the nine months ended September 30, 2014, was lower than the U.S. statutory rate primarily due to income tax deductions allowed for corporate dividends received, the presentation of taxes on our share of earnings generated from equity method investments reflected in net investment income and tax credits, partially offset by an increase in net deferred tax liabilities resulting from the third quarter 2014 enactment of tax legislation in Chile.
	The effective income tax rate for the nine months ended September 30, 2013, was lower than the U.S. statutory rate primarily due to income tax deductions allowed for corporate dividends received, the presentation of taxes on our share of earnings generated from equity method investments reflected in net investment income and lower tax rates of foreign jurisdictions.
	Tax legislation was signed into law in Chile on September 26, 2014, increasing the tax rate over multiple years. Our net deferred tax liabilities increased $58.1 million as a result of this legislative enactment.
	We are a U.S. shareholder in various foreign entities classified as controlled foreign corporations (“CFCs”) for U.S. tax purposes. U.S. shareholders of CFCs are generally required to take into account as gross income in the U.S. certain passive income earned by the CFCs (“Subpart F income”) even if the income is not currently distributed. Temporary exceptions (the “active financing” and “look through” exceptions) were applicable for tax years beginning before January 1, 2014 to avoid the current recognition of Subpart F income derived in either the active conduct of a banking, financing, insurance or similar business or for certain payments between related corporations in different foreign jurisdictions. The U.S. Congress and the President have yet to enact extenders legislation as of September 30, 2014. Therefore, current tax expense has increased by an immaterial amount associated with the U.S. recognition of Subpart F income from our foreign operations. We will reverse any tax expense subject to the active financing and look through exceptions during the 2014 quarter extenders legislation is enacted, assuming the legislation is retroactive to January 1, 2014.
	The U.S. Court of Federal Claims issued a summary judgment determination in the case of Principal Life Insurance Company and Subsidiaries (“Principal Life”) v. the United States on May 9, 2014. The court ruled against Principal Life’s timing of recognition of gains and losses associated with the purchase and sale of principal-only certificates. The ruling caused a re-evaluation of our uncertain tax positions, which resulted in a $47.5 million reduction in net income in the second quarter of 2014. We do not believe there is a reasonable possibility the total amount of uncertain tax benefits will significantly increase or decrease in the next twelve months.
	Unrecognized Tax Benefits
	A summary of the changes in unrecognized tax benefits follows:
		For the nine months ended			For the year ended
		September 30, 2014			December 31, 2013
		(in millions)
	Balance at beginning of period	$	108.9		$	119.5
	Additions based on tax positions related to the current year	9.4			10.5
	Additions for tax positions of prior years	64.4			10.9
	Reductions for tax positions related to the current year	(6.3		)	(3.3		)
	Reductions for tax positions of prior years	—			(28.7		)
	Balance at end of period (1)	$	176.4		$	108.9
	(1)  Of this amount, $61.6 million, if recognized, would reduce the 2014 effective income tax rate. We recognize interest and penalties related to uncertain tax positions in operating expenses.
	As of September 30, 2014 and December 31, 2013, we had recognized $100.0 million and $37.0 million of accumulated pre-tax interest and penalties related to unrecognized tax benefits, respectively.

Employee_and_Agent_Benefits

Employee and Agent Benefits	9 Months Ended
	Sep. 30, 2014
Employee and Agent Benefits	'
Employee and Agent Benefits	'
	6.  Employee and Agent Benefits
	Components of Net Periodic Benefit Cost
								Other postretirement
		Pension benefits						benefits
		For the three months ended						For the three months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
	Service cost	$	13.5		$	14.3		$	0.4		$	0.3
	Interest cost	29.2			25.9			1.7			1.4
	Expected return on plan assets	(33.0		)	(31.8		)	(8.2		)	(7.2		)
	Amortization of prior service benefit	(1.0		)	(2.1		)	(5.0		)	(6.5		)
	Recognized net actuarial (gain) loss	12.5			29.5			(1.0		)	0.3
	Net periodic benefit cost (income)	$	21.2		$	35.8		$	(12.1	)	$	(11.7	)
								Other postretirement
		Pension benefits						benefits
		For the nine months ended						For the nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
	Service cost	$	40.5		$	42.9		$	1.1		$	0.9
	Interest cost	87.8			77.7			5			4.2
	Expected return on plan assets	(99.0		)	(95.6		)	(24.5		)	(21.6		)
	Amortization of prior service benefit	(3.4		)	(6.3		)	(15.2		)	(19.5		)
	Recognized net actuarial (gain) loss	37.8			88.6			(2.7		)	0.9
	Net periodic benefit cost (income)	$	63.7		$	107.3		$	(36.3	)	$	(35.1	)
	Contributions
	Our funding policy for our qualified pension plan is to fund the plan annually in an amount at least equal to the minimum annual contribution required under the Employee Retirement Income Security Act (“ERISA”) and, generally, not greater than the maximum amount that can be deducted for federal income tax purposes. The minimum annual contribution for 2014 will be zero so we will not be required to fund our qualified pension plan during 2014. However, it is possible that we may fund the qualified and nonqualified pension plans in 2014 for a combined total of $125.0 million to $150.0 million. During the three and nine months ended September 30, 2014, we contributed $40.3 million and $97.8 million to these plans, respectively.

Contingencies_Guarantees_and_I

Contingencies, Guarantees and Indemnifications	9 Months Ended
	Sep. 30, 2014
Contingencies, Guarantees and Indemnifications	'
Contingencies, Guarantees and Indemnifications	'
	7.  Contingencies, Guarantees and Indemnifications
	Litigation and Regulatory Contingencies
	We are regularly involved in litigation, both as a defendant and as a plaintiff, but primarily as a defendant. Litigation naming us as a defendant ordinarily arises out of our business operations as a provider of asset management and accumulation products and services; individual life insurance, specialty benefits insurance and our investment activities. Some of the lawsuits may be class actions, or purport to be, and some may include claims for unspecified or substantial punitive and treble damages.
	We may discuss such litigation in one of three ways. We accrue a charge to income and disclose legal matters for which the chance of loss is probable and for which the amount of loss can be reasonably estimated. We may disclose contingencies for which the chance of loss is reasonably possible and provide an estimate of the possible loss or range of loss or a statement that such an estimate cannot be made. Finally, we may voluntarily disclose loss contingencies for which the chance of loss is remote in order to provide information concerning matters that potentially expose us to possible losses.
	In addition, regulatory bodies such as state insurance departments, the SEC, the Financial Industry Regulatory Authority, the Department of Labor and other regulatory agencies regularly make inquiries and conduct examinations or investigations concerning our compliance with, among other things, insurance laws, securities laws, ERISA and laws governing the activities of broker-dealers. We receive requests from regulators and other governmental authorities relating to industry issues and may receive additional requests, including subpoenas and interrogatories, in the future.
	On March 18, 2014, McCaffree Financial Corp. Employee Retirement Program (“McCaffree”) filed a putative class action lawsuit in the United States District Court for the Southern District of Iowa against Principal Life. The complaint alleged, among other things, breach of duty of loyalty, breach of duty of prudence and prohibited transactions under ERISA. McCaffree seeks a nationwide class action on behalf of all participants and beneficiaries of defined contribution retirement plans that invested in any Principal Separate Account in the last six years. McCaffree seeks disgorgement of all fees it alleges Principal Life improperly retained in addition to other general claims for relief. Principal Life has filed a motion to dismiss the case and is aggressively defending the case.
	On August 29, 2013, American Chemicals & Equipment, Inc. 401(k) Retirement Plan (“ACE”) filed a lawsuit in the United States District Court for the Northern District of Alabama against Principal Management Corporation and Principal Global Investors, LLC (the “ACE Defendants”). The lawsuit alleges the ACE Defendants breached their fiduciary duty under Section 36(b) of the Investment Company Act by charging excessive fees on certain of the LifeTime series target date funds. On January 24, 2014, the court granted the motion filed by the ACE Defendants to transfer the case to the Southern District of Iowa. The ACE Defendants continue to aggressively defend the lawsuit.
	On December 2, 2009 and December 4, 2009, two plaintiffs, Cruise and Mullaney, each filed putative class action lawsuits in the United States District Court for the Southern District of New York against us; Principal Life; Principal Global Investors, LLC; Principal Management Corporation; and Principal Real Estate Investors, LLC (the “Cruise/Mullaney Defendants”). The lawsuits alleged the Cruise/Mullaney Defendants failed to manage the Principal U.S. Property Separate Account (“PUSPSA”) in the best interests of investors, improperly imposed a “withdrawal freeze” on September 26, 2008, and instituted a “withdrawal queue” to honor withdrawal requests as sufficient liquidity became available. The two lawsuits, as well as two subsequently filed complaints asserting similar claims, have been consolidated and are now known as In re Principal U.S. Property Account Litigation. Plaintiffs’ request for permission to appeal the denial of class certification was denied by the U.S. Eighth Circuit Court of Appeals on December 31, 2013. The Cruise/Mullaney Defendants are aggressively defending the lawsuit.
	In 2008, Principal Life received approximately $440.0 million in connection with the termination of certain structured transactions and the resulting prepayment of Principal Life’s investment in those transactions. The transactions involved Lehman Brothers Special Financing Inc. and Lehman Brothers Holdings Inc. (collectively, “Lehman”) in various capacities. Subsequent to Lehman’s 2008 bankruptcy filing, its bankruptcy estate initiated several lawsuits seeking to recover from numerous sources significant amounts to which it claims entitlement under various theories. We are one of a large group of defendants to this action, and believe that we have meritorious defenses to Lehman’s claims and intend to aggressively defend against them. The estate’s claim against Principal Life, including interest (which we also dispute), was approximately $532.0 million.
	While the outcome of any pending or future litigation or regulatory matter cannot be predicted, management does not believe that any such matter will have a material adverse effect on our business or financial position. As of September 30, 2014, there were no estimated losses accrued related to the legal matters discussed above because we believe the loss from these matters is not probable and cannot be reasonably estimated.
	We believe all of the litigation contingencies discussed above involve a chance of loss that is either remote or reasonably possible. Unless otherwise noted, all of these matters involve unspecified claim amounts, in which the respective plaintiffs seek an indeterminate amount of damages. To the extent such matters present a reasonably possible chance of loss, we are generally not able to estimate the possible loss or range of loss associated therewith.
	The outcome of such matters is always uncertain, and unforeseen results can occur. It is possible that such outcomes could require us to pay damages or make other expenditures or establish accruals in amounts that we could not estimate at September 30, 2014.
	Guarantees and Indemnifications
	In the normal course of business, we have provided guarantees to third parties primarily related to former subsidiaries and joint ventures. These agreements generally expire through 2019. The maximum exposure under these agreements as of September 30, 2014, was approximately $254.0 million. At inception, the fair value of such guarantees was insignificant. In addition, we believe the likelihood is remote that material payments will be required. Therefore, any liability accrued within our consolidated statements of financial position is insignificant. Should we be required to perform under these guarantees, we generally could recover a portion of the loss from third parties through recourse provisions included in agreements with such parties, the sale of assets held as collateral that can be liquidated in the event that performance is required under the guarantees or other recourse generally available to us; therefore, such guarantees would not result in a material adverse effect on our business or financial position. While the likelihood is remote, such outcomes could materially affect net income in a particular quarter or annual period.
	We manage mandatory privatized social security funds in Chile. By regulation, we have a required minimum guarantee on the funds’ relative return. Because the guarantee has no limitation with respect to duration or amount, the maximum exposure of the guarantee in the future is indeterminable.
	We are also subject to various other indemnification obligations issued in conjunction with divestitures, acquisitions and financing transactions whose terms range in duration and often are not explicitly defined. Certain portions of these indemnifications may be capped, while other portions are not subject to such limitations; therefore, the overall maximum amount of the obligation under the indemnifications cannot be reasonably estimated. At inception, the fair value of such indemnifications was insignificant. In addition, we believe the likelihood is remote that material payments will be required. Therefore, any liability accrued within our consolidated statements of financial position is insignificant. While we are unable to estimate with certainty the ultimate legal and financial liability with respect to these indemnifications, we believe that performance under these indemnifications would not result in a material adverse effect on our business or financial position. While the likelihood is remote, performance under these indemnifications could materially affect net income in a particular quarter or annual period.

Stockholders_Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2014
Stockholders' Equity	'
Stockholders' Equity	'
	8.  Stockholders’ Equity
	Reconciliation of Outstanding Shares
		Series A		Series B		Common
		preferred stock		preferred stock		stock
		(in millions)
	Outstanding shares at January 1, 2013	3		10		293.8
	Shares issued	—		—		4.5
	Treasury stock acquired	—		—		(4.4	)
	Outstanding shares at September 30, 2013	3		10		293.9
	Outstanding shares at January 1, 2014	3		10		295.2
	Shares issued	—		—		3.1
	Treasury stock acquired	—		—		(4.7	)
	Outstanding shares at September 30, 2014	3		10		293.6
	Our Board of Directors has authorized various repurchase programs under which we are allowed to purchase shares of our outstanding common stock. Shares repurchased under these programs are accounted for as treasury stock, carried at cost and reflected as a reduction to stockholders’ equity.
	In May 2012, our Board of Directors authorized a share repurchase program of up to $200.0 million of our outstanding common stock. We completed this program in February 2013. In February 2013, our Board of Directors authorized a share repurchase program of up to $150.0 million of our outstanding common stock, which was completed in March 2014. In February 2014, our Board of Directors authorized a share repurchase program of up to $200.0 million of our outstanding common stock.
	Other Comprehensive Income (Loss)
		For the three months ended									For the nine months ended
		September 30, 2014									September 30, 2014
		Pre-Tax			Tax			After-Tax			Pre-Tax			Tax			After-Tax
		(in millions)
	Net unrealized gains (losses) on available-for-sale securities during the period	$	(301.8	)	$	103.8		$	(198.0	)	$	1,009.90		$	(340.7	)	$	669.2
	Reclassification adjustment for (gains) losses included in net income (1)	4.3			(1.4		)	2.9			(57.4		)	18.8			(38.6		)
	Adjustments for assumed changes in amortization patterns	28.2			(9.8		)	18.4			(71.0		)	24.9			(46.1		)
	Adjustments for assumed changes in policyholder liabilities	149.8			(47.0		)	102.8			(434.7		)	146.8			(287.9		)
	Net unrealized gains (losses) on available-for-sale securities	(119.5		)	45.6			(73.9		)	446.8			(150.2		)	296.6
	Noncredit component of impairment losses on fixed maturities, available-for-sale during the period	14.7			(5.0		)	9.7			82.6			(29.3		)	53.3
	Adjustments for assumed changes in amortization patterns	3.1			(1.2		)	1.9			(5.3		)	1.9			(3.4		)
	Adjustments for assumed changes in policyholder liabilities	(0.9		)	0.3			(0.6		)	(1.5		)	0.5			(1.0		)
	Noncredit component of impairment losses on fixed maturities, available-for-sale (2)	16.9			(5.9		)	11			75.8			(26.9		)	48.9
	Net unrealized gains on derivative instruments during the period	48.4			(17.0		)	31.4			67.7			(23.8		)	43.9
	Reclassification adjustment for (gains) losses included in net income (3)	(1.8		)	0.6			(1.2		)	6.3			(2.4		)	3.9
	Adjustments for assumed changes in amortization patterns	(8.4		)	2.9			(5.5		)	(8.9		)	3.1			(5.8		)
	Adjustments for assumed changes in policyholder liabilities	6.9			(2.4		)	4.5			0.4			(0.1		)	0.3
	Net unrealized gains on derivative instruments	45.1			(15.9		)	29.2			65.5			(23.2		)	42.3
	Foreign currency translation adjustment	(210.3		)	14.5			(195.8		)	(231.2		)	22.8			(208.4		)
	Amortization of prior service cost and actuarial loss included in net periodic benefit cost (4)	5.5			(1.9		)	3.6			16.5			(5.8		)	10.7
	Net unrecognized postretirement benefit obligation	5.5			(1.9		)	3.6			16.5			(5.8		)	10.7
	Other comprehensive income (loss)	$	(262.3	)	$	36.4		$	(225.9	)	$	373.4		$	(183.3	)	$	190.1
		For the three months ended									For the nine months ended
		September 30, 2013									September 30, 2013
		Pre-Tax			Tax			After-Tax			Pre-Tax			Tax			After-Tax
		(in millions)
	Net unrealized losses on available-for-sale securities during the period	$	(40.9	)	$	9.1		$	(31.8	)	$	(1,578.4	)	$	511.6		$	(1,066.8	)
	Reclassification adjustment for losses included in net income (1)	8.4			(2.9		)	5.5			66.8			(22.7		)	44.1
	Adjustments for assumed changes in amortization patterns	29.3			(10.3		)	19			241.1			(84.4		)	156.7
	Adjustments for assumed changes in policyholder liabilities	54.1			(17.5		)	36.6			505.7			(163.4		)	342.3
	Net unrealized gains (losses) on available-for-sale securities	50.9			(21.6		)	29.3			(764.8		)	241.1			(523.7		)
	Noncredit component of impairment losses on fixed maturities, available-for-sale during the period	9.3			(2.9		)	6.4			(8.8		)	3.9			(4.9		)
	Adjustments for assumed changes in amortization patterns	(13.7		)	4.9			(8.8		)	(13.6		)	4.9			(8.7		)
	Adjustments for assumed changes in policyholder liabilities	(0.2		)	0.1			(0.1		)	0.8			(0.3		)	0.5
	Noncredit component of impairment losses on fixed maturities, available-for-sale (2)	(4.6		)	2.1			(2.5		)	(21.6		)	8.5			(13.1		)
	Net unrealized losses on derivative instruments during the period	(45.7		)	15.9			(29.8		)	(31.7		)	11.7			(20.0		)
	Reclassification adjustment for losses included in net income (3)	1.9			(0.8		)	1.1			1.6			(0.8		)	0.8
	Adjustments for assumed changes in amortization patterns	2.6			(1.0		)	1.6			9			(3.2		)	5.8
	Adjustments for assumed changes in policyholder liabilities	2.7			(0.7		)	2			15.3			(5.3		)	10
	Net unrealized losses on derivative instruments	(38.5		)	13.4			(25.1		)	(5.8		)	2.4			(3.4		)
	Foreign currency translation adjustment	(32.0		)	(1.5		)	(33.5		)	(177.3		)	7.8			(169.5		)
	Amortization of prior service cost and actuarial loss included in net periodic benefit cost (4)	21.2			(7.4		)	13.8			63.7			(22.3		)	41.4
	Net unrecognized postretirement benefit obligation	21.2			(7.4		)	13.8			63.7			(22.3		)	41.4
	Other comprehensive loss	$	(3.0	)	$	(15.0	)	$	(18.0	)	$	(905.8	)	$	237.5		$	(668.3	)
	(1)     Pre-tax reclassification adjustments relating to available-for-sale securities are reported in net realized capital gains (losses) on the consolidated statements of operations.
	(2)     Represents the net impact of (1) unrealized gains resulting from reclassification of previously recognized noncredit impairment losses from OCI to net realized capital gains (losses) for fixed maturities with bifurcated OTTI that had additional credit losses or fixed maturities that previously had bifurcated OTTI that have now been sold or are intended to be sold and (2) unrealized losses resulting from reclassification of noncredit impairment losses for fixed maturities with bifurcated OTTI from net realized capital gains (losses) to OCI.
	(3)     See Note 4, Derivative Financial Instruments — Cash Flow Hedges, for further details.
(4)     Pre-tax amortization of prior service cost and actuarial loss included in net periodic benefit cost, which is comprised of amortization of prior service cost (benefit) and recognized net actuarial (gain) loss, is reported in operating expenses on the consolidated statements of operations. See Note 6, Employee and Agent Benefits — Components of Net Periodic Benefit Cost, for further details.
Accumulated Other Comprehensive Income (Loss)
				Noncredit
	Net unrealized			component of			Net unrealized			Foreign			Unrecognized			Accumulated
	gains on			impairment losses			gains (losses) on			currency			postretirement			other
	available-for-sale			on fixed maturities			derivative			translation			benefit			comprehensive
	securities			available-for-sale			instruments			adjustment			obligation			income (loss)
	(in millions)
Balances at January 1, 2013	$	1,418.30		$	(173.9	)	$	(8.7	)	$	(106.9	)	$	(488.5	)	$	640.3
Other comprehensive loss during the period, net of adjustments	(567.8		)	(13.1		)	(4.2		)	(159.2		)	—			(744.3		)
Amounts reclassified from AOCI	44.1			—			0.8			—			41.4			86.3
Other comprehensive loss	(523.7		)	(13.1		)	(3.4		)	(159.2		)	41.4			(658.0		)
Balances at September 30, 2013	$	894.6		$	(187.0	)	$	(12.1	)	$	(266.1	)	$	(447.1	)	$	(17.7	)
Balances at January 1, 2014	$	878.1		$	(167.0	)	$	(10.5	)	$	(361.5	)	$	(155.9	)	$	183.2
Other comprehensive income during the period, net of adjustments	335.2			—			38.4			(201.6		)	—			172
Amounts reclassified from AOCI	(38.6		)	48.9			3.9			—			10.7			24.9
Other comprehensive income	296.6			48.9			42.3			(201.6		)	10.7			196.9
Balances at September 30, 2014	$	1,174.70		$	(118.1	)	$	31.8		$	(563.1	)	$	(145.2	)	$	380.1
Noncontrolling Interest
Interests held by unaffiliated parties in consolidated entities are reflected in noncontrolling interest, which represents the noncontrolling partners’ share of the underlying net assets of our consolidated subsidiaries. Noncontrolling interest that is not redeemable is reported in the equity section of the consolidated statements of financial position.
The noncontrolling interest holders in certain of our subsidiaries maintain an equity interest that is redeemable at the option of the holder, which may be exercised on varying dates. Since redemption of the noncontrolling interest is outside of our control, this interest is presented on the consolidated statements of financial position line item titled “Redeemable noncontrolling interest.” If the interest were to be redeemed, we would be required to purchase such interest at a redemption value based on fair value or a formula that management intended to reasonably approximate fair value based on a fixed multiple of earnings over a measurement period. As such, the carrying value of the redeemable noncontrolling interest is compared to the redemption value at each reporting period. Any adjustments to the carrying amount of the redeemable noncontrolling interest for changes in redemption value prior to exercise of the redemption option are determined after the attribution of net income or loss of the subsidiary and are recognized in the redemption value as they occur. Adjustments to the carrying value of redeemable noncontrolling interest result in adjustments to additional paid-in capital and/or retained earnings. Adjustments are recorded in retained earnings to the extent the redemption value of the redeemable noncontrolling interest exceeds its fair value and will impact the numerator in our earnings per share calculations. All other adjustments to the redeemable noncontrolling interest are recorded in additional paid-in capital.
Following is a reconciliation of the changes in the redeemable noncontrolling interest (in millions):
Balance at January 1, 2013	$	60.4
Net income attributable to redeemable noncontrolling interest	9
Reclassification from stockholders’ equity (1)	173.9
Redeemable noncontrolling interest assumed related to acquisition	1.2
Distributions to redeemable noncontrolling interest	(9.9		)
Purchase of subsidiary shares from redeemable noncontrolling interest	(2.4		)
Change in redemption value of redeemable noncontrolling interest	5.6
Foreign currency translation adjustment	(3.3		)
Balance at September 30, 2013	$	234.5
Balance at January 1, 2014	$	247.2
Net income attributable to redeemable noncontrolling interest	8.3
Contributions from redeemable noncontrolling interest	0.1
Distributions to redeemable noncontrolling interest	(14.4		)
Purchase of subsidiary shares from redeemable noncontrolling interest (2)	(216.8		)
Change in redemption value of redeemable noncontrolling interest	33.2
Foreign currency translation adjustment	(1.5		)
Balance at September 30, 2014	$	56.1
(1)     During the third quarter of 2013, we identified a classification error of certain of our noncontrolling interests. The classification error had no impact on net income, but did impact earnings per share to the extent the redemption value of the redeemable noncontrolling interest exceeds the fair value. We evaluated the classification error and related earnings per share impact based on qualitative and quantitative factors in accordance with SEC Staff Accounting Bulletins 99 and 108 and concluded the impact was not material in the current or any prior quarterly or annual periods presented. During the third quarter of 2013, we recorded a $173.9 million increase to redeemable noncontrolling interest and a corresponding decrease to stockholders’ equity. See related discussion in Note 12, Earnings Per Share.
(2)     The decrease during the third quarter of 2014 was primarily due to an increased ownership stake in Columbus Circle Investors.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Measurements	'
Fair Value Measurements	'
	9.  Fair Value Measurements
	We use fair value measurements to record fair value of certain assets and liabilities and to estimate fair value of financial instruments not recorded at fair value but required to be disclosed at fair value. Certain financial instruments, particularly policyholder liabilities other than investment-type insurance contracts, are excluded from these fair value disclosure requirements.
	Valuation Hierarchy
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (an exit price). The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three levels. The level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety considering factors specific to the asset or liability.
	·         Level 1 — Fair values are based on unadjusted quoted prices in active markets for identical assets or liabilities. Our Level 1 assets and liabilities primarily include exchange traded equity securities, mutual funds and U.S. Treasury bonds.
	·         Level 2 — Fair values are based on inputs other than quoted prices within Level 1 that are observable for the asset or liability, either directly or indirectly. Our Level 2 assets and liabilities primarily include fixed maturities (including public and private bonds), equity securities, derivatives and other investments for which public quotations are not available but that are priced by third-party pricing services or internal models using substantially all observable inputs.
	·         Level 3 — Fair values are based on at least one significant unobservable input for the asset or liability. Our Level 3 assets and liabilities include certain assets and liabilities priced using broker quotes or other valuation methods that utilize at least one significant unobservable input. These include fixed maturities, private equity securities, real estate and commercial mortgage loan investments of our separate accounts, commercial mortgage loan investments and obligations of consolidated VIEs for which the fair value option was elected, complex derivatives, embedded derivatives and equity method real estate investments for which the fair value option was elected.
	Determination of Fair Value
	The following discussion describes the valuation methodologies and inputs used for assets and liabilities measured at fair value on a recurring basis or disclosed at fair value. The techniques utilized in estimating the fair values of financial instruments are reliant on the assumptions used. Care should be exercised in deriving conclusions about our business, its value or financial position based on the fair value information of financial instruments presented below.
	Fair value estimates are made based on available market information and judgments about the financial instrument at a specific point in time. Such estimates do not consider the tax impact of the realization of unrealized gains or losses. In addition, the disclosed fair value may not be realized in the immediate settlement of the financial instrument. We validate prices through an investment analyst review process, which includes validation through direct interaction with external sources, review of recent trade activity or use of internal models. In circumstances where broker quotes are used to value an instrument, we generally receive one non-binding quote. Broker quotes are validated through an investment analyst review process, which includes validation through direct interaction with external sources and use of internal models or other relevant information. We did not make any significant changes to our valuation processes during 2014.
	Fixed Maturities
	Fixed maturities include bonds, ABS, redeemable preferred stock and certain nonredeemable preferred securities. When available, the fair value of fixed maturities is based on quoted prices of identical assets in active markets. These are reflected in Level 1 and primarily include U.S. Treasury bonds and actively traded redeemable corporate preferred securities.
	When quoted prices of identical assets in active markets are not available, our first priority is to obtain prices from third party pricing vendors. We have regular interaction with these vendors to ensure we understand their pricing methodologies and to confirm they are utilizing observable market information. Their methodologies vary by asset class and include inputs such as estimated cash flows, benchmark yields, reported trades, broker quotes, credit quality, industry events and economic events. Fixed maturities with validated prices from pricing services, which includes the majority of our public fixed maturities in all asset classes, are generally reflected in Level 2. Also included in Level 2 are corporate bonds where quoted market prices are not available, for which an internal model using substantially all observable inputs or a matrix pricing valuation approach is used. In the matrix approach, securities are grouped into pricing categories that vary by sector, rating and average life. Each pricing category is assigned a risk spread based on studies of observable public market data from the investment professionals assigned to specific security classes. The expected cash flows of the security are then discounted back at the current Treasury curve plus the appropriate risk spread. Although the matrix valuation approach provides a fair valuation of each pricing category, the valuation of an individual security within each pricing category may actually be impacted by company specific factors.
	If we are unable to price a fixed maturity security using prices from third party pricing vendors or other sources specific to the asset class, we may obtain a broker quote or utilize an internal pricing model specific to the asset utilizing relevant market information, to the extent available and where at least one significant unobservable input is utilized, which are reflected in Level 3 and can include fixed maturities across all asset classes. As of September 30, 2014, less than 1% of our fixed maturities were valued using internal pricing models, which were classified as Level 3 assets accordingly.
	The primary inputs, by asset class, for valuations of the majority of our Level 2 investments from third party pricing vendors or our internal pricing valuation approach are described below.
	U.S. Government and Agencies/Non-U.S. Governments. Inputs include recently executed market transactions, interest rate yield curves, maturity dates, market price quotations and credit spreads relating to similar instruments.
	States and Political Subdivisions. Inputs include Municipal Securities Rulemaking Board reported trades, U.S. Treasury and other benchmark curves, material event notices, new issue data and obligor credit ratings.
	Corporate. Inputs include recently executed transactions, market price quotations, benchmark yields, issuer spreads and observations of equity and credit default swap curves related to the issuer. For private placement corporate securities valued through the matrix valuation approach inputs include the current Treasury curve and risk spreads based on sector, rating and average life of the issuance.
	RMBS, CMBS, Collateralized Debt Obligations and Other Debt Obligations. Inputs include cash flows, priority of the tranche in the capital structure, expected time to maturity for the specific tranche, reinvestment period remaining and performance of the underlying collateral including prepayments, defaults, deferrals, loss severity of defaulted collateral and, for RMBS, prepayment speed assumptions. Other inputs include market indices and recently executed market transactions.
	Equity Securities
	Equity securities include mutual funds, common stock, nonredeemable preferred stock and mandatory regulatory required investments. Fair values of equity securities are determined using quoted prices in active markets for identical assets when available, which are reflected in Level 1. When quoted prices are not available, we may utilize internal valuation methodologies appropriate for the specific asset that use observable inputs such as underlying share prices or the net asset value (“NAV”), which are reflected in Level 2. Fair values might also be determined using broker quotes or through the use of internal models or analysis that incorporate significant assumptions deemed appropriate given the circumstances and consistent with what other market participants would use when pricing such securities, which are reflected in Level 3.
	Derivatives
	The fair values of exchange-traded derivatives are determined through quoted market prices, which are reflected in Level 1. Exchange-traded derivatives include futures that are settled daily such that their fair value is not reflected in the consolidated statements of financial position. The fair values of derivative instruments cleared through centralized clearinghouses are determined through market prices published by the clearinghouses, which are reflected in Level 2. The clearinghouses may utilize the overnight indexed swap (“OIS”) curve in their valuation. The fair values of bilateral OTC derivative instruments are determined using either pricing valuation models that utilize market observable inputs or broker quotes. The majority of our bilateral OTC derivatives are valued with models that use market observable inputs, which are reflected in Level 2. Significant inputs include contractual terms, interest rates, currency exchange rates, credit spread curves, equity prices and volatilities. These valuation models consider projected discounted cash flows, relevant swap curves and appropriate implied volatilities. Certain bilateral OTC derivatives utilize unobservable market data, primarily independent broker quotes that are nonbinding quotes based on models that do not reflect the result of market transactions, which are reflected in Level 3.
	Our non-cleared derivative contracts are generally documented under ISDA Master Agreements, which provide for legally enforceable set-off and close-out netting of exposures to specific counterparties. Collateral arrangements are bilateral and based on current ratings of each entity. We utilize the LIBOR interest rate curve to value our positions, which includes a credit spread. This credit spread incorporates an appropriate level of nonperformance risk into our valuations given the current ratings of our counterparties, as well as the collateral agreements in place. Counterparty credit risk is routinely monitored to ensure our adjustment for non-performance risk is appropriate. Our centrally cleared derivative contracts are conducted with regulated centralized clearinghouses, which provide for daily exchange of cash collateral equal to the difference in the daily market values of those contracts that eliminates the non-performance risk on these trades.
	Interest Rate Contracts. For non-cleared contracts we use discounted cash flow valuation techniques to determine the fair value of interest rate swaps using observable swap curves as the inputs. These are reflected in Level 2. For centrally cleared contracts we use published prices from clearinghouses. These are reflected in Level 2. In addition, we have a limited number of complex inflation-linked interest rate swaps, interest rate collars and swaptions that are valued using broker quotes. These are reflected in Level 3.
	Foreign Exchange Contracts. We use discounted cash flow valuation techniques that utilize observable swap curves and exchange rates as the inputs to determine the fair value of foreign currency swaps. These are reflected in Level 2. Currency forwards are valued using observable market inputs, including forward currency exchange rates. These are reflected in Level 2. In addition, we have a limited number of non-standard currency swaps that are valued using broker quotes. These are reflected within Level 3.
	Equity Contracts. We use an option pricing model using observable implied volatilities, dividend yields, index prices and swap curves as the inputs to determine the fair value of equity options. These are reflected in Level 2.
	Credit Contracts. We use either the ISDA Credit Default Swap Standard discounted cash flow model that utilizes observable default probabilities and recovery rates as inputs or broker prices to determine the fair value of credit default swaps. These are reflected in Level 3. In addition, we have a limited number of total return swaps that are valued based on the observable quoted price of underlying equity indices. These are reflected in Level 2.
	Other Investments
	Other investments reported at fair value include seed money investments, other investment funds, commercial mortgage loans of consolidated VIEs and equity method real estate investments for which the fair value option was elected.
	The fair value of seed money and other investment funds is determined using the NAV of the fund. The NAV of the funds represents the price at which we feel we would be able to initiate a transaction. Seed money investments in mutual funds for which the NAV is published are reflected in Level 1. Seed money investments in mutual funds in markets that do not have a published NAV and other investment funds, which are relatively illiquid due to restrictions on sale, are reflected in Level 2.
	Commercial mortgage loans of consolidated VIEs and equity method real estate investments for which the fair value option was elected are reflected in Level 3. Fair value of the commercial mortgage loans is computed utilizing a discount rate based on the current market. The market discount rate is then adjusted based on various factors that differentiate it from our pool of loans. The equity method real estate investments consist of underlying real estate and debt. The real estate fair value is estimated using a discounted cash flow valuation model that utilizes public real estate market data inputs such as transaction prices, market rents, vacancy levels, leasing absorption, market cap rates and discount rates. The debt fair value is estimated using a discounted cash flow analysis based on our incremental borrowing rate for similar borrowing arrangements.
	Cash and Cash Equivalents
	Certain cash equivalents are reported at fair value on a recurring basis and include money market instruments and other short-term investments with maturities of less than three months. Fair values of these cash equivalents may be determined using public quotations, when available, which are reflected in Level 1. When public quotations are not available, because of the highly liquid nature of these assets, carrying amounts may be used to approximate fair values, which are reflected in Level 2.
	Separate Account Assets
	Separate account assets include equity securities, debt securities and derivative instruments, for which fair values are determined as previously described, and are reflected in Level 1, Level 2 and Level 3. Separate account assets also include commercial mortgage loans, for which the fair value is estimated by discounting the expected total cash flows using market rates that are applicable to the yield, credit quality and maturity of the loans. The market clearing spreads vary based on mortgage type, weighted average life, rating and liquidity. These are reflected in Level 3. Finally, separate account assets include real estate, for which the fair value is estimated using discounted cash flow valuation models that utilize public real estate market data inputs such as transaction prices, market rents, vacancy levels, leasing absorption, market cap rates and discount rates. In addition, each property is appraised annually by an independent appraiser. The real estate included in separate account assets is recorded net of related mortgage encumbrances for which the fair value is estimated using discounted cash flow analysis based on our incremental borrowing rate for similar borrowing arrangements. The real estate within the separate accounts is reflected in Level 3.
	Investment-Type Insurance Contracts
	Certain annuity contracts and other investment-type insurance contracts include embedded derivatives that have been bifurcated from the host contract and that are measured at fair value on a recurring basis, which are reflected in Level 3. The key assumptions for calculating the fair value of the embedded derivative liabilities are market assumptions (such as equity market returns, interest rate levels, market volatility and correlations) and policyholder behavior assumptions (such as lapse, mortality, utilization and withdrawal patterns). Risk margins are included in the policyholder behavior assumptions. The assumptions are based on a combination of historical data and actuarial judgment. The embedded derivative liabilities are valued using stochastic models that incorporate a spread reflecting our own creditworthiness.
	The assumption for our own non-performance risk for investment-type insurance contracts and any embedded derivatives bifurcated from certain annuity and investment-type insurance contracts is based on the current market credit spreads for debt-like instruments that we have issued and are available in the market.
	Other Liabilities
	Certain obligations reported in other liabilities include embedded derivatives to deliver underlying securities of structured investments to third parties. The fair value of the embedded derivatives is calculated based on the value of the underlying securities that are valued based on prices obtained from third party pricing vendors as utilized and described in our discussion of how fair value is determined for fixed maturities, which are reflected in Level 2.
	Additionally, obligations of consolidated VIEs for which the fair value option was elected are included in other liabilities. These obligations are valued either based on prices obtained from third party pricing vendors as utilized and described in our discussion of how fair value is determined for fixed maturities, which are reflected in Level 2, or broker quotes, which are reflected in Level 3.
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	Assets and liabilities measured at fair value on a recurring basis are summarized below.
		As of September 30, 2014
		Assets/
		(liabilities)
		measured at			Fair value hierarchy level
		fair value			Level 1			Level 2			Level 3
		(in millions)
	Assets
	Fixed maturities, available-for-sale:
	U.S. government and agencies	$	892.1		$	519		$	373.1		$	—
	Non-U.S. governments	904.7			—			863.4			41.3
	States and political subdivisions	4,094.00			—			4,092.30			1.7
	Corporate	32,020.20			40.3			31,757.70			222.2
	Residential mortgage-backed securities	2,809.00			—			2,809.00			—
	Commercial mortgage-backed securities	4,012.30			—			4,006.90			5.4
	Collateralized debt obligations	480.8			—			419.2			61.6
	Other debt obligations	4,414.40			—			4,368.70			45.7
	Total fixed maturities, available-for-sale	49,627.50			559.3			48,690.30			377.9
	Fixed maturities, trading	609.4			4.9			465.2			139.3
	Equity securities, available-for-sale	124.8			40.3			67.1			17.4
Equity securities, trading	807.6			102.5			705.1			—
Derivative assets (1)	558.7			—			501			57.7
Other investments (2)	420.6			3.3			293			124.3
Cash equivalents (3)	473.2			—			473.2			—
Sub-total excluding separate account assets	52,621.80			710.3			51,194.90			716.6
Separate account assets	138,296.70			71,356.30			61,163.00			5,777.40
Total assets	$	190,918.50		$	72,066.60		$	112,357.90		$	6,494.00
Liabilities
Investment-type insurance contracts (4)	$	(94.1	)	$	—		$	—		$	(94.1	)
Derivative liabilities (1)	(794.6		)	—			(756.8		)	(37.8		)
Other liabilities (4)	(307.8		)	—			(246.8		)	(61.0		)
Total liabilities	$	(1,196.5	)	$	—		$	(1,003.6	)	$	(192.9	)
Net assets	$	189,722.00		$	72,066.60		$	111,354.30		$	6,301.10
	As of December 31, 2013
	Assets/
	(liabilities)
	measured at			Fair value hierarchy level
	fair value			Level 1			Level 2			Level 3
	(in millions)
Assets
Fixed maturities, available-for-sale:
U.S. government and agencies	$	780.5		$	409.3		$	371.2		$	—
Non-U.S. governments	996.8			—			949.3			47.5
States and political subdivisions	3,658.00			—			3,656.20			1.8
Corporate	31,919.00			40.3			31,714.70			164
Residential mortgage-backed securities	2,845.20			—			2,845.20			—
Commercial mortgage-backed securities	4,026.40			—			4,024.80			1.6
Collateralized debt obligations	363.4			—			325.6			37.8
Other debt obligations	4,167.80			—			4,083.70			84.1
Total fixed maturities, available-for-sale	48,757.10			449.6			47,970.70			336.8
Fixed maturities, trading	563.1			—			393.2			169.9
Equity securities, available-for-sale	110.5			38.1			55.5			16.9
Equity securities, trading	716.9			105.1			611.8			—
Derivative assets (1)	665.1			—			590.9			74.2
Other investments (2)	361.1			6.8			211.4			142.9
Cash equivalents (3)	1,459.00			—			1,459.00			—
Sub-total excluding separate account assets	52,632.80			599.6			51,292.50			740.7
Separate account assets	130,018.40			67,215.10			57,538.10			5,265.20
Total assets	$	182,651.20		$	67,814.70		$	108,830.60		$	6,005.90
Liabilities
Investment-type insurance contracts (4)	$	(6.9	)	$	—		$	—		$	(6.9	)
Derivative liabilities (1)	(1,024.6		)	—			(985.0		)	(39.6		)
Other liabilities (4)	(322.1		)	—			(248.2		)	(73.9		)
Total liabilities	$	(1,353.6	)	$	—		$	(1,233.2	)	$	(120.4	)
Net assets	$	181,297.60		$	67,814.70		$	107,597.40		$	5,885.50
(1)     Within the consolidated statements of financial position, derivative assets are reported with other investments and derivative liabilities are reported with other liabilities. Refer to Note 4, Derivative Financial Instruments, for further information on fair value by class of derivative instruments. Our derivatives are primarily Level 2, with the exception of certain credit default swaps and other swaps that are Level 3.
(2)     Primarily includes seed money investments, other investment funds, commercial mortgage loans of consolidated VIEs and equity method investments reported at fair value.
(3)     Includes money market instruments and short-term investments with a maturity date of three months or less when purchased.
(4)     Includes bifurcated embedded derivatives that are reported at fair value within the same line item in the consolidated statements of financial position in which the host contract is reported. Other liabilities also include obligations of consolidated VIEs reported at fair value.
Changes in Level 3 Fair Value Measurements
The reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) are summarized as follows:
	For the three months ended September 30, 2014																					Changes in
	Beginning									Net									Ending			unrealized
	asset/			Total realized/unrealized						purchases,									asset/			gains (losses)
	(liability)			gains (losses)						sales,									(liability)			included in
	balance						Included in			issuances									balance			net income
	as of			Included in			other			and			Transfers			Transfers			as of			relating to
	June 30,			net income			comprehensive			settlements			into			out of			September 30,			positions still
	2014			-1			income			-4			Level 3			Level 3			2014			held (1)
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	39.6		$	—		$	(0.2	)	$	1.9		$	—		$	—		$	41.3		$	—
States and political subdivisions	1.7			—			—			—			—			—			1.7			—
Corporate	170			(1.4		)	(2.8		)	40.7			15.7			—			222.2			(1.4		)
Commercial mortgage-backed securities	6.7			(1.0		)	0.2			0.2			0.7			(1.4		)	5.4			(0.9		)
Collateralized debt obligations	68.5			—			0.1			9.5			—			(16.5		)	61.6			—
Other debt obligations	47.1			—			—			(1.4		)	—			—			45.7			—
Total fixed maturities, available-for-sale	333.6			(2.4		)	(2.7		)	50.9			16.4			(17.9		)	377.9			(2.3		)
Fixed maturities, trading	159.6			3.7			—			(24.0		)	—			—			139.3			0.2
Equity securities, available-for-sale	17.5			(0.3		)	0.2			—			—			—			17.4			(0.3		)
Derivative assets	62.3			(14.4		)	—			9.8			—			—			57.7			(14.3		)
Other investments	134.6			3.8			—			(14.1		)	—			—			124.3			3.8
Separate account assets (2)	5,533.60			167			(0.3		)	79			2.3			(4.2		)	5,777.40			163.7
Liabilities
Investment-type insurance contracts	(37.6		)	(62.8		)	—			6.3			—			—			(94.1		)	(56.1		)
Derivative liabilities	(24.7		)	(13.3		)	(0.6		)	0.8			—			—			(37.8		)	(14.5		)
Other liabilities (3)	(79.9		)	9.9			—			9			—			—			(61.0		)	9.8
	For the three months ended September 30, 2013																					Changes in
	Beginning									Net									Ending			unrealized
	asset/			Total realized/unrealized						purchases,									asset/			gains (losses)
	(liability)			gains (losses)						sales,									(liability)			included in
	balance			Included in			Included in			issuances									balance			net income
	as of			net			other			and			Transfers			Transfers			as of			relating to
	June 30,			income			comprehensive			settlements			into			out of			September 30,			positions still
	2013			-1			income			-4			Level 3			Level 3			2013			held (1)
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	44.7		$	—		$	(0.3	)	$	3.4		$	—		$	—		$	47.8		$	—
States and political subdivisions	1.7			—			0.1			—			—			—			1.8			—
Corporate	168.1			(0.1		)	2.7			17.1			4.7			(29.5		)	163			(0.1		)
Collateralized debt obligations	40.7			—			(0.1		)	—			—			(2.6		)	38			—
Other debt obligations	18.4			(0.3		)	0.6			13.6			15			—			47.3			(0.3		)
Total fixed maturities, available-for-sale	273.6			(0.4		)	3			34.1			19.7			(32.1		)	297.9			(0.4		)
Fixed maturities, trading	170.7			2.1			—			0.1			—			—			172.9			2.1
Equity securities, available-for-sale	16.9			—			0.3			—			—			—			17.2			—
Derivative assets	56.9			1			—			(0.4		)	—			—			57.5			1.2
Other investments	116.5			1.8			—			22.2			—			—			140.5			1.9
Separate account assets (2)	4,841.70			134.6			0.1			(33.7		)	4.9			(6.3		)	4,941.30			122
Liabilities
Investment-type insurance contracts	(74.2		)	17.6			—			7.3			—			—			(49.3		)	19.8
Derivative liabilities	(70.0		)	14.1			0.3			5.6			—			—			(50.0		)	14.2
Other liabilities (3)	(59.6		)	(7.5		)	—			—			—			—			(67.1		)	(7.6		)
	For the nine months ended September 30, 2014																					Changes in
	Beginning									Net									Ending			unrealized
	asset/			Total realized/unrealized						purchases,									asset/			gains (losses)
	(liability)			gains (losses)						sales,									(liability)			included in
	balance			Included			Included in			issuances									balance			net income
	as of			in net			other			and			Transfers			Transfers			as of			relating to
	December 31,			income			comprehensive			settlements			into			out of			September 30,			positions still
	2013			-1			income			-4			Level 3			Level 3			2014			held (1)
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	47.5		$	(0.1	)	$	(0.2	)	$	(5.9	)	$	—		$	—		$	41.3		$	(0.1	)
States and political subdivisions	1.8			—			—			(0.1		)	—			—			1.7			—
Corporate	164			(1.6		)	(1.7		)	21			46.6			(6.1		)	222.2			(1.5		)
Commercial mortgage-backed securities	1.6			(1.6		)	1.3			(0.2		)	6.8			(2.5		)	5.4			(1.5		)
Collateralized debt obligations	37.8			—			1.4			46.4			—			(24.0		)	61.6			—
Other debt obligations	84.1			—			1.1			(9.8		)	—			(29.7		)	45.7			—
Total fixed maturities, available-for-sale	336.8			(3.3		)	1.9			51.4			53.4			(62.3		)	377.9			(3.1		)
Fixed maturities, trading	169.9			9.5			—			(40.1		)	—			—			139.3			0.8
Equity securities, available-for-sale	16.9			(0.3		)	0.6			—			0.2			—			17.4			(0.3		)
Derivative assets	74.2			(26.4		)	—			9.9			—			—			57.7			(26.4		)
Other investments	142.9			6.6			—			(25.2		)	—			—			124.3			6.6
Separate account assets (2)	5,265.20			358.4			(0.2		)	161.3			4.4			(11.7		)	5,777.40			359.9
Liabilities
Investment-type insurance contracts	(6.9		)	(109.9		)	—			22.7			—			—			(94.1		)	(109.9		)
Derivative liabilities	(39.6		)	0.5			0.7			0.6			—			—			(37.8		)	(3.7		)
Other liabilities (3)	(73.9		)	3.9			—			9			—			—			(61.0		)	4.5
	For the nine months ended September 30, 2013																					Changes in
	Beginning									Net									Ending			unrealized
	asset/			Total realized/unrealized						purchases,									asset/			gains (losses)
	(liability)			gains (losses)						sales,									(liability)			included in
	balance			Included			Included in			issuances									balance			net income
	as of			in net			other			and			Transfers			Transfers			as of			relating to
	December 31,			income			comprehensive			settlements			into			out of			September 30,			positions still
	2012			-1			income			-4			Level 3			Level 3			2013			held (1)
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	44.3		$	(0.1	)	$	(0.8	)	$	4.4		$	—		$	—		$	47.8		$	(0.1	)
States and political subdivisions	1.9			—			—			(0.1		)	—			—			1.8			—
Corporate	174.5			(4.9		)	(7.0		)	(25.3		)	105.3			(79.6		)	163			(2.0		)
Collateralized debt obligations	77.6			2.1			7.4			(56.0		)	31.7			(24.8		)	38			—
Other debt obligations	14.7			(0.3		)	3			12.7			17.2			—			47.3			(0.3		)
Total fixed maturities, available-for-sale	313			(3.2		)	2.6			(64.3		)	154.2			(104.4		)	297.9			(2.4		)
Fixed maturities, trading	166.8			6			—			0.1			—			—			172.9			6.1
Equity securities, available-for-sale	15.3			—			1.9			—			—			—			17.2			—
Derivative assets	75.1			(21.3		)	—			3.7			—			—			57.5			(21.6		)
Other investments	113.9			7.1			—			19.5			—			—			140.5			7.1
Separate account assets (2)	4,616.00			427.2			—			(108.1		)	12.7			(6.5		)	4,941.30			406.3
Liabilities
Investment-type insurance contracts	(170.5		)	111.2			—			10			—			—			(49.3		)	109.2
Derivative liabilities	(102.6		)	44.4			(0.2		)	8.4			—			—			(50.0		)	43.8
Other liabilities (3)	(39.6		)	(27.5		)	—			—			—			—			(67.1		)	(27.5		)
(1)       Both realized gains (losses) and mark-to-market unrealized gains (losses) are generally reported in net realized capital gains (losses) within the consolidated statements of operations. Realized and unrealized gains (losses) on certain fixed maturities, trading and certain derivatives used in relation to certain trading portfolios are reported in net investment income within the consolidated statements of operation.
(2)       Gains and losses for separate account assets do not impact net income as the change in value of separate account assets is offset by a change in value of separate account liabilities. Foreign currency translation adjustments related to the Principal International segment separate account assets are recorded in AOCI and are offset by foreign currency translation adjustments of the corresponding separate account liabilities.
(3)       Certain embedded derivatives reported in other liabilities are part of a cash flow hedge, with the effective portion of the unrealized gains (losses) recorded in AOCI.
(4)       Gross purchases, sales, issuances and settlements were:
	For the three months ended September 30, 2014
													Net purchases,
													sales, issuances
	Purchases			Sales			Issuances			Settlements			and settlements
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	2.2		$	—		$	—		$	(0.3	)	$	1.9
Corporate	46.5			(5.5		)	—			(0.3		)	40.7
Commercial mortgage-backed securities	—			—			—			0.2			0.2
Collateralized debt obligations	9.7			—			—			(0.2		)	9.5
Other debt obligations	—			—			—			(1.4		)	(1.4		)
Total fixed maturities, available-for-sale	58.4			(5.5		)	—			(2.0		)	50.9
Fixed maturities, trading	—			(10.0		)	—			(14.0		)	(24.0		)
Derivative assets	9.8			—			—			—			9.8
Other investments	—			—			—			(14.1		)	(14.1		)
Separate account assets (5)	228.5			(127.3		)	(196.5		)	174.3			79
Liabilities
Investment-type insurance contracts	—			—			4.2			2.1			6.3
Derivative liabilities	(0.6		)	1.4			—			—			0.8
Other liabilities	—			9			—			—			9
	For the three months ended September 30, 2013
													Net purchases,
													sales, issuances
	Purchases			Sales			Issuances			Settlements			and settlements
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	3.7		$	—		$	—		$	(0.3	)	$	3.4
Corporate	18.2			(0.7		)	—			(0.4		)	17.1
Other debt obligations	15			—			—			(1.4		)	13.6
Total fixed maturities, available-for-sale	36.9			(0.7		)	—			(2.1		)	34.1
Fixed maturities, trading	—			—			—			0.1			0.1
Derivative assets	—			(0.4		)	—			—			(0.4		)
Other investments	25.7			—			—			(3.5		)	22.2
Separate account assets (5)	33.6			(54.7		)	(1.4		)	(11.2		)	(33.7		)
Liabilities
Investment-type insurance contracts	—			—			5.4			1.9			7.3
Derivative liabilities	—			5.6			—			—			5.6
	For the nine months ended September 30, 2014
													Net purchases,
													sales, issuances
	Purchases			Sales			Issuances			Settlements			and settlements
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. government	$	5.8		$	(10.8	)	$	—		$	(0.9	)	$	(5.9	)
States and political subdivisions	—			—			—			(0.1		)	(0.1		)
Corporate	64.5			(39.2		)	—			(4.3		)	21
Commercial mortgage-backed securities	—			—			—			(0.2		)	(0.2		)
Collateralized debt obligations	61.3			—			—			(14.9		)	46.4
Other debt obligations	—			—			—			(9.8		)	(9.8		)
Total fixed maturities, available-for-sale	131.6			(50.0		)	—			(30.2		)	51.4
Fixed maturities, trading	—			(10.0		)	—			(30.1		)	(40.1		)
Derivative assets	9.9			—			—			—			9.9
Other investments	0.2			—			—			(25.4		)	(25.2		)
Separate account assets (5)	467.2			(257.5		)	(290.1		)	241.7			161.3
Liabilities
Investment-type insurance contracts	—			—			18.7			4			22.7
Derivative liabilities	(0.8		)	1.4			—			—			0.6
Other liabilities	—			9			—			—			9
	For the nine months ended September 30, 2013
													Net purchases,
													sales, issuances
	Purchases			Sales			Issuances			Settlements			and settlements
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. government	$	9.2		$	(3.9	)	$	—		$	(0.9	)	$	4.4
State and political subdivisions	—			—			—			(0.1		)	(0.1		)
Corporate	29.6			(32.4		)	—			(22.5		)	(25.3		)
Collateralized debt obligations	17			(47.4		)	—			(25.6		)	(56.0		)
Other debt obligations	15			—			—			(2.3		)	12.7
Total fixed maturities, available-for-sale	70.8			(83.7		)	—			(51.4		)	(64.3		)
Fixed maturities, trading	—			—			—			0.1			0.1
Derivative assets	7.2			(3.5		)	—			—			3.7
Other investments	28.3			—			—			(8.8		)	19.5
Separate account assets (5)	143.2			(223.4		)	(7.6		)	(20.3		)	(108.1		)
Liabilities
Investment-type insurance contracts	—			—			5.6			4.4			10
Derivative liabilities	(3.1		)	11.5			—			—			8.4
(5)         Issuances and settlements include amounts related to mortgage encumbrances associated with real estate in our separate accounts.
Transfers
Transfers of assets and liabilities measured at fair value on a recurring basis between fair value hierarchy levels are summarized below.
	For the three months ended September 30, 2014
	Transfers out			Transfers out			Transfers out			Transfers out			Transfers out			Transfers out
	of Level 1 into			of Level 1 into			of Level 2 into			of Level 2 into			of Level 3 into			of Level 3 into
	Level 2			Level 3			Level 1			Level 3			Level 1			Level 2
	(in millions)
Assets
Fixed maturities, available-for- sale:
Corporate	$	—		$	—		$	—		$	15.7		$	—		$	—
Commercial mortgage-backed securities	—			—			—			0.7			—			1.4
Collateralized debt obligations	—			—			—			—			—			16.5
Total fixed maturities, available-for-sale	—			—			—			16.4			—			17.9
Separate account assets	2.1			—			17.5			2.3			—			4.2
	For the three months ended September 30, 2013
	Transfers out			Transfers out			Transfers out			Transfers out			Transfers out			Transfers out
	of Level 1 into			of Level 1 into			of Level 2 into			of Level 2 into			of Level 3 into			of Level 3 into
	Level 2			Level 3			Level 1			Level 3			Level 1			Level 2
	(in millions)
Assets
Fixed maturities, available-for- sale:
Corporate	$	—		$	—		$	—		$	4.7		$	—		$	29.5
Collateralized debt obligations	—			—			—			—			—			2.6
Other debt obligations	—			—			—			15			—			—
Total fixed maturities, available-for-sale	—			—			—			19.7			—			32.1
Separate account assets	7.1			—			6.9			4.9			—			6.3
	For the nine months ended September 30, 2014
	Transfers out			Transfers out			Transfers out			Transfers out			Transfers out			Transfers out
	of Level 1 into			of Level 1 into			of Level 2 into			of Level 2 into			of Level 3 into			of Level 3 into
	Level 2			Level 3			Level 1			Level 3			Level 1			Level 2
	(in millions)
Assets
Fixed maturities, available-for- sale:
Corporate	$	—		$	—		$	—		$	46.6		$	—		$	6.1
Commercial mortgage-backed securities	—			—			—			6.8			—			2.5
Collateralized debt obligations	—			—			—			—			—			24
Other debt obligations	—			—			—			—			—			29.7
Total fixed maturities, available-for-sale	—			—			—			53.4			—			62.3
Equity securities, available-for- sale	—			—			—			0.2			—			—
Separate account assets	17.5			—			71.3			4.4			—			11.7
	For the nine months ended September 30, 2013
	Transfers out			Transfers out			Transfers out			Transfers out			Transfers out			Transfers out
	of Level 1 into			of Level 1 into			of Level 2 into			of Level 2 into			of Level 3 into			of Level 3 into
	Level 2			Level 3			Level 1			Level 3			Level 1			Level 2
	(in millions)
Assets
Fixed maturities, available-for- sale:
Corporate	$	—		$	—		$	—		$	105.3		$	—		$	79.6
Collateralized debt obligations	—			—			—			31.7			—			24.8
Other debt obligations	—			—			—			17.2			—			—
Total fixed maturities, available-for-sale	—			—			—			154.2			—			104.4
Separate account assets	250.9			0.1			11.7			12.6			—			6.5
Transfers between fair value hierarchy levels are recognized at the beginning of the reporting period.
In 2013, we had significant transfers of separate account assets between Level 1 and Level 2, primarily related to foreign equity securities. When these securities are valued at the local close price of the exchange where the assets traded, they are reflected in Level 1. When events materially affecting the value occur between the close of the local exchange and the New York Stock Exchange, we use adjusted prices determined by a third party pricing vendor to update the foreign market closing prices and the fair value is reflected in Level 2.
Assets transferred into Level 3 during the three and nine months ended September 30, 2014 and 2013, primarily included those assets for which we are now unable to obtain pricing from a recognized third party pricing vendor as well as assets that were previously priced using a matrix valuation approach that may no longer be relevant when applied to asset-specific situations.
Assets transferred out of Level 3 during the three and nine months ended September 30, 2014 and 2013, included those for which we are now able to obtain pricing from a recognized third party pricing vendor or from internal models using substantially all market observable information.
Quantitative Information about Level 3 Fair Value Measurements
The following table provides quantitative information about the significant unobservable inputs used for recurring fair value measurements categorized within Level 3, excluding assets and liabilities for which significant quantitative unobservable inputs are not developed internally, which primarily consists of those valued using broker quotes. Refer to “Assets and liabilities measured at fair value on a recurring basis” for a complete valuation hierarchy summary.
	As of September 30, 2014
	Assets /
	(liabilities)
	measured at			Valuation		Unobservable		Input/range of		Weighted
	fair value			technique(s)		input description		inputs		average
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	10.7		Discounted cash flow		Discount rate (1)		2.00%		2.00%
						Illiquidity premium		50 basis points (“bps”)		50bps
Corporate	71.7			Discounted cash flow		Discount rate (1)		1.8%-7.5%		4.20%
						Comparability adjustment		0bps-4bps		0bps
						Illiquidity premium		0bps-50bps		16bps
Commercial mortgage-backed securities	5			Discounted cash flow		Discount rate (1)		4.0%-17.6%		17.60%
Collateralized debt obligations	9.7			Discounted cash flow		Discount rate (1)		2.60%		2.60%
Other debt obligations	31.2			Discounted cash flow		Discount rate (1)		1.4%-5.0%		2.30%
						Illiquidity premium		50bps-1,000bps		283bps
Fixed maturities, trading	15.1			Discounted cash flow		Discount rate (1)		1.7%-124.1%		3.30%
						Illiquidity premium		200bps-1,400bps		450bps
	100.4			See note (2)
	As of September 30, 2014
	Assets /
	(liabilities)
	measured at		Valuation		Unobservable		Input/range of		Weighted
	fair value		technique(s)		input description		inputs		average
	(in millions)
Other investments	41.9		Discounted cash flow - commercial mortgage loans of consolidated VIEs		Discount rate (1)		4.20%		4.20%
					Illiquidity premium		70bps		70bps
	82.4		Discounted cash flow - equity method real estate investments		Discount rate (1)		7.5%-8.1%		7.80%
					Terminal capitalization rate		5.5%-6.8%		6.10%
					Average market rent growth rate		3.4%-3.9%		3.60%
			Discounted cash flow - equity method real estate investment - debt		Loan to value		37.9%-60.3%		49.10%
					Credit spread rate		1.8%-2.0%		1.90%
Separate account assets	5,605.60		Discounted cash flow - mortgage loans		Discount rate (1)		1.0%-6.1%		3.10%
					Illiquidity premium		0bps-60bps		7bps
					Credit spread rate		62bps-556bps		203bps
			Discounted cash flow - real estate		Discount rate (1)		6.0%-22.8%		7.50%
					Terminal capitalization rate		4.5%-9.5%		6.40%
					Average market rent growth rate		1.4%-5.0%		3.10%
			Discounted cash flow - real estate debt		Loan to value		8.5%-65.3%		47.80%
					Credit spread rate		1.1%-4.7%		2.40%
	As of September 30, 2014
	Assets /
	(liabilities)
	measured at		Valuation		Unobservable		Input/range of		Weighted
	fair value		technique(s)		input description		inputs		average
	(in millions)
Liabilities
Investment-type insurance contracts	(94.1	)	Discounted cash flow		Long duration interest rate		3.1%-3.2% (3)
					Long-term equity market volatility		14.9%-38.4%
					Non-performance risk		0.1%-1.2%
					Utilization rate		See note (4)
					Lapse rate		0.5%-14.6%
					Mortality rate		See note (5)
Derivative liabilities	(11.9	)	See note (2)
Other liabilities	(61.0	)	See note (2)
	As of December 31, 2013
	Assets /
	(liabilities)
	measured at			Valuation		Unobservable		Input/range of		Weighted
	fair value			technique(s)		input description		inputs		average
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	11.7		Discounted cash flow		Discount rate (1)		2.00%		2.00%
						Illiquidity premium		50 bps		50bps
Corporate	70.1			Discounted cash flow		Discount rate (1)		1.9%-7.7%		4.40%
						Illiquidity premium		0bps-25bps		15bps
						Earnings before interest, taxes, depreciation and amortization multiple		0x-4.5x		0.2x
						Comparability adjustment		0bps - 125bps		43bps
						Probability of default		0%-100%		5.40%
						Potential loss severity		0%-16%		0.90%
Commercial mortgage-backed securities	1.6			Discounted cash flow		Discount rate (1)		1.5%-4.5%		1.50%
Collateralized debt obligations	13.6			Discounted cash flow		Discount rate (1)		1.50%		1.50%
						Illiquidity premium		400bps		400bps
	As of December 31, 2013
	Assets /
	(liabilities)
	measured at		Valuation		Unobservable		Input/range of		Weighted
	fair value		technique(s)		input description		inputs		average
	(in millions)
Other debt obligations	33.6		Discounted cash flow		Discount rate (1)		2.0%-15.0%		6.70%
					Illiquidity premium		0bps-50bps		11bps
Fixed maturities, trading	36.2		Discounted cash flow		Discount rate (1)		1.6%-83.0%		3.40%
					Illiquidity premium		0bps-1,400bps		370bps
	110.4		See note (2)
Other investments	68.1		Discounted cash flow - commercial mortgage loans of consolidated VIEs		Discount rate (1)		4.80%		4.80%
					Illiquidity premium		94bps		94bps
	74.8		Discounted cash flow - equity method real estate investment		Discount rate (1)		7.8%-8.1%		7.90%
					Terminal capitalization rate		5.5%-6.8%		6.10%
					Average market rent growth rate		3.5%-3.6%		3.60%
			Discounted cash flow - equity method real estate investment debt		Loan to value		40.5%-61.0%		50.70%
					Credit spread rate		1.5%-2.0%		1.80%
	As of December 31, 2013
	Assets /
	(liabilities)
	measured at		Valuation		Unobservable		Input/range of		Weighted
	fair value		technique(s)		input description		inputs		average
	(in millions)
Separate account assets	5,090.40		Discounted cash flow - mortgage loans		Discount rate (1)		0.6%-5.6%		3.30%
					Illiquidity premium		0bps-60bps		12bps
					Credit spread rate		32bps-440bps		214bps
			Discounted cash flow - real estate		Discount rate (1)		6.0%-16.0%		7.60%
					Terminal capitalization rate		4.5%-9.0%		6.60%
					Average market rent growth rate		2.4%-4.7%		3.00%
			Discounted cash flow - real estate debt		Loan to value		11.0%-55.9%		50.30%
					Credit spread rate		1.5%-5.2%		3.30%
Liabilities
Investment-type insurance contracts	(6.9	)	Discounted cash flow		Long duration interest rate		3.8%-3.9% (3)
					Long-term equity market volatility		15.0%-40.1%
					Non-performance risk		0.2%-1.2%
					Utilization rate		See note (4)
					Lapse rate		0.5%-14.6%
					Mortality rate		See note (5)
Derivative liabilities	(19.9	)	See note (2)
Other liabilities	(73.9	)	See note (2)
(1)     Represents market comparable interest rate or an index adjusted rate used as the base rate in the discounted cash flow analysis prior to any credit spread, illiquidity or other adjustments, where applicable.
(2)     Relates to a consolidated collateralized private investment vehicle that is a VIE. Fixed maturities, trading represents the underlying collateral of the investment structure and consists of high-grade fixed maturity investments, which are over-collateralized based on outstanding notes priced at par. The derivative liability represents credit default swaps that are valued using a correlation model to the credit default swap (“CDS”) Index (“CDX”) and inputs to the valuation are based on observable market data such as the end of period swap curve, CDS constituents of the index and spread levels of the index, as well as CDX tranche spreads. The other liabilities represent obligations to third party note holders due at maturity or termination of the trust. The value of the obligations reflect the third parties’ interest in the investment structure.
(3)     Represents the range of rate curves used in the valuation analysis that we have determined market participants would use when pricing the instrument. Derived from interpolation between observable 20 and 30-year swap rates.
(4)     This input factor is the number of contractholders taking withdrawals as well as the amount and timing of the withdrawals and a range does not provide a meaningful presentation.
(5)     This input is based on an appropriate industry mortality table and a range does not provide a meaningful presentation.
Market comparable discount rates are used as the base rate in the discounted cash flows used to determine the fair value of certain assets. Increases or decreases in the credit spreads on the comparable assets could cause the fair value of the assets to significantly decrease or increase, respectively. Additionally, we may adjust the base discount rate or the modeled price by applying an illiquidity premium given the highly structured nature of certain assets. Increases or decreases in this illiquidity premium could cause significant decreases or increases, respectively, in the fair value of the asset.
Embedded derivatives can be either assets or liabilities within the investment-type insurance contracts line item, depending on certain inputs at the reporting date.  Increases to an asset or decreases to a liability are described as increases to fair value. Increases or decreases in market volatilities could cause significant decreases or increases, respectively, in the fair value of embedded derivatives in investment-type insurance contracts. Long duration interest rates are used as the mean return when projecting the growth in the value of associated account value and impact the discount rate used in the discounted future cash flows valuation. The amount of claims will increase if account value is not sufficient to cover guaranteed withdrawals. Increases or decreases in risk free rates could cause the fair value of the embedded derivative to significantly increase or decrease, respectively. Increases or decreases in our own credit risks, which impact the rates used to discount future cash flows, could significantly increase or decrease, respectively, the fair value of the embedded derivative. All of these changes in fair value would impact net income.
Decreases or increases in the mortality rate assumption could cause the fair value of the embedded derivative to decrease or increase, respectively. Decreases or increases in the overall lapse rate assumption could cause the fair value of the embedded derivative to decrease or increase, respectively. The lapse rate assumption varies dynamically based on the relationship of the guarantee and associated account value. A stronger or weaker dynamic lapse rate assumption could cause the fair value of the embedded derivative to decrease or increase, respectively. The utilization rate assumption includes how many contractholders will take withdrawals, when they will take them and how much of their benefit they will take.  Increases or decreases in the assumption of the number of contractholders taking withdrawals could cause the fair value of the embedded derivative to decrease or increase, respectively. Assuming contractholders take withdrawals earlier or later could cause the fair value of the embedded derivative to decrease or increase, respectively. Assuming contractholders take more or less of their benefit could cause the fair value of the embedded derivative to decrease or increase, respectively.
Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis
Certain assets are measured at fair value on a nonrecurring basis. During the nine months ended September 30, 2014, certain mortgage loans had been marked to fair value of $63.8 million. The net impact of impairments and improvements in estimated fair value of previously impaired loans resulted in a net loss of $9.7 million and $9.1 million for the three and nine months ended September 30, 2014, respectively, that was recorded in net realized capital gains (losses) as part of the mortgage loan valuation allowance. This includes the impact of certain loans no longer on our books. These collateral-dependent mortgage loans are a Level 3 fair value measurement, as fair value is based on the fair value of the underlying real estate collateral, which is estimated using appraised values that involve significant unobservable inputs. The fair value of the underlying collateral is determined based on a discounted cash flow valuation either from an external broker opinion of value or an internal model. Significant inputs used in the internal model discounted cash flow calculation include: a discount rate, terminal capitalization rate and average market rent growth. The ranges of inputs used in the fair value measurements for the mortgage loans marked to fair value during the nine months ended September 30, 2014, were:
Discount rate =font> 8.8% - 11.0%
Terminal capitalization rate =font> 7.3% - 9.0%
Average market rent growth =font> 2.5% - 10.9%
During the nine months ended September 30, 2013, certain mortgage loans had been marked to fair value of $101.6 million. The net impact of impairments and improvements in estimated fair value of previously impaired loans resulted in a net loss of $4.6 million and $22.3 million for the three and nine months ended September 30, 2013, respectively, that was recorded in net realized capital gains (losses) as part of the mortgage loan valuation allowance. This includes the impact of certain loans no longer on our books. These collateral-dependent mortgage loans are a Level 3 fair value measurement, as fair value is based on the fair value of the underlying real estate collateral, which is estimated using appraised values that involve significant unobservable inputs.
Discount rate =font> 8.0% - 20.0%
Terminal capitalization rate =font> 7.5% - 10.5%
Average market rent growth =font> 1.0% - 10.9%
During the nine months ended September 30, 2013, certain mortgage servicing rights had been written down to fair value of $7.6 million. The net impact of impairments and improvements in estimated fair value of previously impaired mortgage servicing rights resulted in a net gain of zero and $1.3 million for the three and nine months ended September 30, 2013, that was recorded in operating expenses. These mortgage servicing rights are a Level 3 fair value measurement, as fair value is determined by calculating the present value of the future servicing cash flows from the underlying mortgage loans. The discount rate used in calculating the present value of the future servicing cash flows was 3.9% for the nine months ended September 30, 2013.
Fair Value Option
We elected fair value accounting for certain assets and liabilities of consolidated VIEs for which it was not practicable for us to determine the carrying value. The fair value option was elected for commercial mortgage loans reported with other investments and obligations reported with other liabilities in the consolidated statements of financial position. The changes in fair value of these items are reported in net realized capital gains (losses) on the consolidated statements of operations.
The fair value and aggregate contractual principal amounts of commercial mortgage loans for which the fair value option has been elected were $41.8 million and $38.5 million as of September 30, 2014, and $68.1 million and $64.0 million as of December 31, 2013, respectively. The change in fair value of the loans resulted in a $0.2 million and $0.5 million pre-tax loss for the three months ended September 30, 2014 and 2013, respectively, and a $(0.8) million and $1.1 million pre-tax gain (loss) for the nine months ended September 30, 2014 and 2013, respectively, none of which related to instrument-specific credit risk. None of these loans were more than 90 days past due or in nonaccrual status. Interest income on these commercial mortgage loans is included in net investment income on the consolidated statements of operations and is recorded based on the effective interest rates as determined at the closing of the loan. Interest income recorded on these commercial mortgage loans was $3.2 million and $1.4 million for the three months ended September 30, 2014 and 2013, respectively, and $5.4 million and $4.3 million for the nine months ended September 30, 2014 and 2013, respectively.
The fair value and aggregate unpaid principal amounts of obligations for which the fair value option has been elected were $65.8 million and $138.9 million as of September 30, 2014, and $104.9 million and $174.4 million as of December 31, 2013, respectively. For the three months ended September 30, 2014 and 2013, the change in fair value of the obligations resulted in a pre-tax gain (loss) of $10.4 million and $(7.2) million, which includes a pre-tax gain (loss) of $8.9 million and $(7.6) million related to instrument-specific credit risk that is estimated based on credit spreads and quality ratings, respectively. For the nine months ended September 30, 2014 and 2013, the change in fair value of the obligations resulted in a pre-tax gain (loss) of $4.7 million and $(26.3) million, which includes a pre-tax gain (loss) of $2.9 million and $(27.5) million related to instrument-specific credit risk that is estimated based on credit spreads and quality ratings, respectively. Interest expense recorded on these obligations is included in operating expenses on the consolidated statements of operations and was $2.7 million and $0.9 million for the three months ended September 30, 2014 and 2013, respectively, and $3.8 million and $2.7 million for the nine months ended September 30, 2014 and 2013, respectively.
We invest in real estate ventures for the purpose of earning investment returns and for capital appreciation. We elected the fair value option for certain ventures that are subject to the equity method of accounting because the nature of the investments are to add value to the properties and generate income from the operations of the properties. Other equity method real estate investments are not fair valued because the investments mainly generate income from the operations of the underlying properties. These investments are reported with other investments in the consolidated statements of financial position. The changes in fair value are reported in net investment income on the consolidated statements of operations. The fair value of the equity method investments for which the fair value option has been elected was $82.4 million and $74.8 million as of September 30, 2014 and December 31, 2013, respectively. The change in fair value of the investments resulted in a $4.0 million and $2.3 million pre-tax gain for the three months ended September 30, 2014 and 2013, respectively, and $7.6 million and $6.1 million pre-tax gain for the nine months ended September 30, 2014 and 2013, respectively.
Financial Instruments Not Reported at Fair Value
The carrying value and estimated fair value of financial instruments not recorded at fair value on a recurring basis but required to be disclosed at fair value were as follows:
	September 30, 2014
							Fair value hierarchy level
	Carrying amount			Fair value			Level 1			Level 2			Level 3
	(in millions)
Assets (liabilities)
Mortgage loans	$	11,744.90		$	12,233.70		$	—		$	—		$	12,233.70
Policy loans	837.7			1,031.80			—			—			1,031.80
Other investments	195			195.5			—			164.6			30.9
Cash and cash equivalents	797.6			797.6			797.6			—			—
Investments-type insurance contracts	(28,371.8		)	(28,494.4		)	—			(5,282.5		)	(23,211.9		)
Short-term debt	(126.3		)	(126.3		)	—			(126.3		)	—
Long-term debt	(2,529.2		)	(2,756.7		)	—			(2,676.3		)	(80.3		)
Separate account liabilities	(127,104.9		)	(125,755.0		)	—			—			(125,755.0		)
Bank deposits	(1,946.7		)	(1,953.1		)	(1,294.1		)	(659.0		)	—
Cash collateral payable	(79.6		)	(79.6		)	(79.6		)	—			—
	December 31, 2013
							Fair value hierarchy level
	Carrying amount			Fair value			Level 1			Level 2			Level 3
	(in millions)
Assets (liabilities)
Mortgage loans	$	11,533.60		$	11,773.50		$	—		$	—		$	11,773.50
Policy loans	859.7			963.3			—			—			963.3
Other investments	174			174.7			—			140.9			33.8
Cash and cash equivalents	912.8			912.8			912.8			—			—
Investments-type insurance contracts	(29,909.6		)	(30,093.1		)	—			(5,902.2		)	(24,190.9		)
Short-term debt	(150.6		)	(150.6		)	—			(150.6		)	—
Long-term debt	(2,601.4		)	(2,692.1		)	—			(2,639.0		)	(53.1		)
Separate account liabilities	(119,500.7		)	(118,059.7		)	—			—			(118,059.7		)
Bank deposits	(1,949.0		)	(1,951.1		)	(1,252.2		)	(698.9		)	—
Cash collateral payable	(32.5		)	(32.5		)	(32.5		)	—			—
Mortgage Loans
Fair values of commercial and residential mortgage loans are primarily determined by discounting the expected cash flows at current treasury rates plus an applicable risk spread, which reflects credit quality and maturity of the loans. The risk spread is based on market clearing levels for loans with comparable credit quality, maturities and risk. The fair value of mortgage loans may also be based on the fair value of the underlying real estate collateral less cost to sell, which is estimated using appraised values. These are reflected in Level 3.
Policy Loans
Fair values of policy loans are estimated by discounting expected cash flows using a risk-free rate based on the Treasury curve. The expected cash flows reflect an estimate of timing of the repayment of the loans. These are reflected in Level 3.
Other Investments
The fair value of commercial loans and certain consumer loans included in other investments is calculated by discounting expected cash flows through the estimated maturity date using market interest rates that reflect the credit and interest rate risk inherent in the loans. The estimate of term to maturity is based on historical experience, adjusted as required, for current economic and lending conditions. The effect of nonperforming loans is considered in assessing the credit risk inherent in the fair value estimate. These are reflected in Level 3. The carrying value of the remaining investments reported in this line item approximate their fair value and are of a short-term nature. These are reflected in Level 2.
Cash and Cash Equivalents
Certain cash equivalents not reported at fair value include short-term investments with maturities of less than three months for which public quotations are not available to use in determining fair value. Because of the highly liquid nature of these assets, carrying amounts are used to approximate fair value, which are reflected in Level 2. The carrying amounts of the remaining cash and cash equivalents that are not reported at fair value on a recurring basis approximate their fair value, which are reflected in Level 1 given the nature of cash.
Investment-Type Insurance Contracts
The fair values of our reserves and liabilities for investment-type insurance contracts are determined via a third party pricing vendor or using discounted cash flow analyses when we are unable to find a price from third party pricing vendors. Third party pricing on various outstanding medium-term notes and funding agreements is based on observable inputs such as benchmark yields and spreads based on reported trades for our medium-term notes and funding agreement issuances. These are reflected in Level 2. The discounted cash flow analyses for the remaining contracts is based on current interest rates, including non-performance risk, being offered for similar contracts with maturities consistent with those remaining for the investment-type contracts being valued. These are reflected in Level 3. Investment-type insurance contracts include insurance, annuity and other policy contracts that do not involve significant mortality or morbidity risk and are only a portion of the policyholder liabilities appearing in the consolidated statements of financial position. Insurance contracts include insurance, annuity and other policy contracts that do involve significant mortality or morbidity risk. The fair values for our insurance contracts, other than investment-type contracts, are not required to be disclosed.
Short-Term Debt
The carrying amount of short-term debt approximates its fair value because of the relatively short time between origination of the debt instrument and its maturity, which is reflected in Level 2.
Long-Term Debt
Long-term debt primarily includes senior note issuances for which the fair values are determined using inputs that are observable in the market or that can be derived from or corroborated with observable market data. These are reflected in Level 2. Additionally, our long-term debt includes non-recourse mortgages and notes payable that are primarily financings for real estate developments for which the fair values are estimated using discounted cash flow analysis based on our incremental borrowing rate for similar borrowing arrangements. These are reflected in Level 3.
Separate Account Liabilities
Fair values of separate account liabilities, excluding insurance-related elements, are estimated based on market assumptions around what a potential acquirer would pay for the associated block of business, including both the separate account assets and liabilities. As the applicable separate account assets are already reflected at fair value, any adjustment to the fair value of the block is an assumed adjustment to the separate account liabilities. To compute fair value, the separate account liabilities are originally set to equal separate account assets because these are pass-through contracts. The separate account liabilities are reduced by the amount of future fees expected to be collected that are intended to offset upfront acquisition costs already incurred that a potential acquirer would not have to pay. The estimated future fees are adjusted by an adverse deviation discount and the amount is then discounted at a risk-free rate as measured by the yield on Treasury securities at maturities aligned with the estimated timing of fee collection. These are reflected in Level 3.
Bank Deposits
The fair value of deposits of our Principal Bank subsidiary with no stated maturity is equal to the amount payable on demand (i.e., their carrying amounts). These are reflected in Level 1. The fair value of certificates of deposit is based on the discounted value of contractual cash flows. The discount is estimated using the rates currently offered for deposits of similar remaining maturities. These are reflected in Level 2.
Cash Collateral Payable
The carrying amount of the payable associated with our obligation to return the cash collateral received under derivative credit support annex (collateral) agreements approximates its fair value, which is reflected in Level 1.

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2014
Segment Information	'
Segment Information	'
	10.  Segment Information
	We provide financial products and services through the following segments: Retirement and Investor Services, Principal Global Investors, Principal International and U.S. Insurance Solutions. In addition, we have a Corporate segment. The segments are managed and reported separately because they provide different products and services, have different strategies or have different markets and distribution channels.
	The Retirement and Investor Services segment provides retirement and related financial products and services primarily to businesses, their employees and other individuals.
	The Principal Global Investors segment provides asset management services to our asset accumulation business, our insurance operations, the Corporate segment and third-party clients.
	The Principal International segment has operations in Brazil, Chile, China, Hong Kong Special Administrative Region, India, Mexico and Southeast Asia. We focus on countries with large middle classes, favorable demographics and growing long-term savings, ideally with defined contribution markets. We entered these countries through acquisitions, start-up operations and joint ventures.
	The U.S. Insurance Solutions segment provides individual life insurance and specialty benefits, which consists of group dental and vision insurance, individual and group disability insurance, group life insurance and non-medical fee-for-service claims administration, throughout the United States.
	The Corporate segment manages the assets representing capital that has not been allocated to any other segment. Financial results of the Corporate segment primarily reflect our financing activities (including interest expense and preferred stock dividends), income on capital not allocated to other segments, inter-segment eliminations, income tax risks and certain income, expenses and other after-tax adjustments not allocated to the segments based on the nature of such items. Results of our exited group medical insurance business are reported in this segment.
	Management uses segment operating earnings in goal setting, as a basis for determining employee compensation and in evaluating performance on a basis comparable to that used by securities analysts. We determine segment operating earnings by adjusting U.S. GAAP net income for net realized capital gains (losses), as adjusted, and other after-tax adjustments which management believes are not indicative of overall operating trends. Net realized capital gains (losses), as adjusted, are net of income taxes, related changes in the amortization pattern of DAC and other actuarial balances, recognition of deferred front-end fee revenues for sales charges on retirement and life insurance products and services, amortization of hedge accounting book value adjustments for certain discontinued hedges, net realized capital gains and losses distributed, noncontrolling interest capital gains and losses and certain market value adjustments to fee revenues. Net realized capital gains (losses), as adjusted, exclude periodic settlements and accruals on derivative instruments not designated as hedging instruments and exclude certain market value adjustments of embedded derivatives and realized capital gains (losses) associated with our exited group medical insurance business. Segment operating revenues exclude net realized capital gains (losses) (except periodic settlements and accruals on derivatives not designated as hedging instruments), including their impact on recognition of front-end fee revenues, certain market value adjustments to fee revenues and amortization of hedge accounting book value adjustments for certain discontinued hedges, and revenue from our exited group medical insurance business. Segment operating revenues include operating revenues from real estate properties that qualify for discontinued operations. While these items may be significant components in understanding and assessing the consolidated financial performance, management believes the presentation of segment operating earnings enhances the understanding of our results of operations by highlighting earnings attributable to the normal, ongoing operations of the business.
	The accounting policies of the segments are consistent with the accounting policies for the consolidated financial statements, with the exception of income tax allocation. The Corporate segment functions to absorb the risk inherent in interpreting and applying tax law. The segments are allocated tax adjustments consistent with the positions we took on tax returns. The Corporate segment results reflect any differences between the tax returns and the estimated resolution of any disputes.
	The following tables summarize select financial information by segment and reconcile segment totals to those reported in the consolidated financial statements:
		September 30, 2014			December 31, 2013
		(in millions)
	Assets:
	Retirement and Investor Services	$	133,306.20		$	128,736.70
	Principal Global Investors	1,200.10			1,312.10
	Principal International	56,974.60			54,243.60
	U.S. Insurance Solutions	21,215.00			20,033.60
	Corporate	3,726.90			3,865.40
	Total consolidated assets	$	216,422.80		$	208,191.40
		For the three months ended						For the nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
	Operating revenues by segment:
	Retirement and Investor Services	$	1,324.70		$	1,136.50		$	3,851.00		$	3,387.60
	Principal Global Investors	173.6			160.9			517.9			482.8
	Principal International	294.5			303.3			952.2			825.9
	U.S. Insurance Solutions	821			767.6			2,436.80			2,318.60
	Corporate	(61.1		)	(52.5		)	(163.3		)	(149.1		)
	Total segment operating revenues	2,552.70			2,315.80			7,594.60			6,865.80
	Net realized capital losses, net of related revenue adjustments	(68.2		)	(76.7		)	(25.0		)	(253.4		)
	Exited group medical insurance business	(0.2		)	0.5			—			4.5
	Total revenues per consolidated statements of operations	$	2,484.30		$	2,239.60		$	7,569.60		$	6,616.90
	Operating earnings (loss) by segment, net of related income taxes:
	Retirement and Investor Services	$	204.3		$	172.9		$	632.9		$	515.2
	Principal Global Investors	25.3			23.1			79.6			72.4
	Principal International	73.8			50.7			205.1			153.6
	U.S. Insurance Solutions	83.3			54			175.7			136.9
	Corporate	(33.0		)	(31.5		)	(99.4		)	(104.2		)
	Total segment operating earnings, net of related income taxes	353.7			269.2			993.9			773.9
	Net realized capital losses, as adjusted (1)	(55.2		)	(22.8		)	(47.3		)	(126.8		)
	Other after-tax adjustments (2)	(57.8		)	(0.7		)	(105.9		)	(0.8		)
	Net income available to common stockholders per consolidated statements of operations	$	240.7		$	245.7		$	840.7		$	646.3
	(1)         Net realized capital gains (losses), as adjusted, is derived as follows:
		For the three months ended						For the nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
	Net realized capital gains (losses):
	Net realized capital gains (losses)	$	(46.4	)	$	(50.9	)	$	41		$	(181.9	)
	Certain derivative and hedging-related adjustments	(21.9		)	(25.6		)	(66.4		)	(70.7		)
	Recognition of front-end fee (revenue) expense	0.1			(0.2		)	0.4			(0.8		)
	Net realized capital losses, net of related revenue adjustments	(68.2		)	(76.7		)	(25.0		)	(253.4		)
	Amortization of deferred acquisition costs and other actuarial balances	(3.6		)	26.7			(26.8		)	44.8
	Capital gains distributed	(8.8		)	(0.2		)	(18.1		)	(11.1		)
	Certain market value adjustments of embedded derivatives	5.7			18.7			6			18.4
	Noncontrolling interest capital gains	(0.1		)	(0.2		)	(0.2		)	(0.2		)
	Income tax effect	19.8			8.9			16.8			74.7
	Net realized capital losses, as adjusted	$	(55.2	)	$	(22.8	)	$	(47.3	)	$	(126.8	)
	(2)         For the three months ended September 30, 2014, other after-tax adjustments included the negative effect of an increase in net deferred tax liabilities resulting from third quarter 2014 enactment of tax legislation in Chile ($58.1 million) and the positive effect of gains associated with our exited group medical insurance business that does not qualify for discontinued operations accounting treatment under U.S. GAAP ($0.3 million).
	For the three months ended September 30, 2013, other after-tax adjustments included the negative effect of losses associated with our exited group medical insurance business that does not qualify for discontinued operations accounting treatment under U.S. GAAP.
	For the nine months ended September 30, 2014, other after-tax adjustments included the negative effect of: (a) an increase in net deferred tax liabilities resulting from third quarter 2014 enactment of tax legislation in Chile ($58.1 million); (b) the impact of a court ruling on some uncertain tax positions ($47.5 million) and (c) losses associated with our exited group medical insurance business that does not qualify for discontinued operations accounting treatment under U.S. GAAP ($0.3 million).
	For the nine months ended September 30, 2013, other after-tax adjustments included the negative effect of losses associated with our exited group medical insurance business that does not qualify for discontinued operations accounting treatment under U.S. GAAP.
The following table summarizes operating revenues for our products and services:
	For the three months ended						For the nine months ended
	September 30,						September 30,
	2014			2013			2014			2013
	(in millions)
Retirement and Investor Services:
Full service accumulation	$	392.1		$	369.9		$	1,170.00		$	1,087.70
Principal Funds	219.7			194.8			638.2			565.9
Individual annuities	335.6			334.5			1,082.90			881.8
Bank and trust services	21.9			24.4			63.7			74.9
Eliminations	(38.8		)	(38.3		)	(116.3		)	(109.1		)
Total Accumulation	930.5			885.3			2,838.50			2,501.20
Investment only	73.4			83.1			234.5			260.6
Full service payout	320.8			168.1			778			625.8
Total Guaranteed	394.2			251.2			1,012.50			886.4
Total Retirement and Investor Services	1,324.70			1,136.50			3,851.00			3,387.60
Principal Global Investors (1)	173.6			160.9			517.9			482.8
Principal International	294.5			303.3			952.2			825.9
U.S. Insurance Solutions:
Individual life insurance	382.7			362.7			1,148.50			1,110.20
Specialty benefits insurance	438.3			405			1,288.40			1,208.60
Eliminations	—			(0.1		)	(0.1		)	(0.2		)
Total U.S. Insurance Solutions	821			767.6			2,436.80			2,318.60
Corporate	(61.1		)	(52.5		)	(163.3		)	(149.1		)
Total operating revenues	$	2,552.70		$	2,315.80		$	7,594.60		$	6,865.80
Total operating revenues	$	2,552.70		$	2,315.80		$	7,594.60		$	6,865.80
Net realized capital losses (except periodic settlements and accruals on non-hedge derivatives), including recognition of front-end fee revenues and certain market value adjustments to fee revenues	(68.2		)	(76.7		)	(25.0		)	(253.4		)
Exited group medical insurance business	(0.2		)	0.5			—			4.5
Total revenues per consolidated statements of operations	$	2,484.30		$	2,239.60		$	7,569.60		$	6,616.90
(1)         Reflects inter-segment revenues of $71.0 million and $61.1 million for the three months ended September 30, 2014 and 2013, respectively, and $214.4 million and $179.9 million for the nine months ended September 30, 2014 and 2013, respectively.

StockBased_Compensation_Plans

Stock-Based Compensation Plans	9 Months Ended
	Sep. 30, 2014
Stock-Based Compensation Plans	'
Stock-Based Compensation Plans	'
	11.  Stock-Based Compensation Plans
	As of September 30, 2014, we have the 2014 Stock Incentive Plan (approved by shareholders at the May 20, 2014 annual shareholder meeting), the Employee Stock Purchase Plan, the 2014 Directors Stock Plan (approved by shareholders at the May 20, 2014 annual shareholder meeting), the Long-Term Performance Plan, the Amended and Restated 2010 Stock Incentive Plan, the 2005 Directors Stock Plan, the Stock Incentive Plan and the Directors Stock Plan (“Stock Based Compensation Plans”). As of May 20, 2014, no new grants will be made under the Amended and Restated 2010 Stock Incentive Plan or the 2005 Directors Stock Plan. No grants have been made under the Stock Incentive Plan, the Directors Stock Plan or the Long-Term Performance Plan since at least 2005. Under the terms of the 2014 Stock Incentive Plan, grants may be nonqualified stock options, incentive stock options qualifying under Section 422 of the Internal Revenue Code, restricted stock, restricted stock units, stock appreciation rights, performance shares, performance units or other stock-based awards. The 2014 Directors Stock Plan provides for the grant of nonqualified stock options, restricted stock, restricted stock units or other stock-based awards to our nonemployee directors. To date, we have not granted any incentive stock options, restricted stock or performance units under any plans.
	As of September 30, 2014, the maximum number of new shares of common stock that were available for grant under the 2014 Stock Incentive Plan and the 2014 Directors Stock Plan was 13.2 million.
	For awards with graded vesting, we use an accelerated expense attribution method. The compensation cost that was charged against income for stock-based awards granted under the Stock-Based Compensation Plans was as follows:
		For the nine months ended September 30,
		2014		2013
		(in millions)
	Compensation cost	$	50.3	$	48.5
	Related income tax benefit	16.4		14.6
	Capitalized as part of an asset	1.9		1.9
	Nonqualified Stock Options
	Nonqualified stock options were granted to certain employees under the 2014 Stock Incentive Plan. Total options granted were 0.6 million for the nine months ended September 30, 2014. The fair value of these options was determined using the Black-Scholes option valuation model assuming a weighted-average dividend yield of 2.5 percent, a weighted-average expected volatility of 53.2 percent, a weighted-average risk-free interest rate of 2.0 percent and a weighted-average expected term of 6.5 years. The weighted-average estimated fair value of stock options granted during the nine months ended September 30, 2014, was $18.89 per share.
	As of September 30, 2014, there was $5.1 million of total unrecognized compensation cost related to nonvested stock options. The cost is expected to be recognized over a weighted-average service period of approximately 1.3 years.
	Performance Share Awards
	Performance share awards were granted to certain employees under the 2014 Stock Incentive Plan. Total performance share awards granted were 0.3 million for the nine months ended September 30, 2014. The performance share awards granted represent initial target awards and do not reflect potential increases or decreases resulting from the final performance results to be determined at the end of the performance period. The actual number of shares to be awarded at the end of each performance period will range between 0% and 150% of the initial target awards. The fair value of performance share awards is determined based on the closing stock price of our common shares on the grant date. The weighted-average grant date fair value of these performance share awards granted was $44.88 per common share.
	As of September 30, 2014, there was $7.1 million of total unrecognized compensation cost related to nonvested performance share awards granted. The cost is expected to be recognized over a weighted-average service period of approximately 1.3 years.
	Restricted Stock Units
	Restricted stock units were issued to certain employees and agents pursuant to the 2014 Stock Incentive Plan and non-employee directors pursuant to the 2014 Directors Stock Plan. Total restricted stock units granted were 0.9 million for the nine months ended September 30, 2014. The fair value of restricted stock units is determined based on the closing stock price of our common shares on the grant date. The weighted-average grant date fair value of these restricted stock units granted was $45.01 per common share.
	As of September 30, 2014, there was $49.8 million of total unrecognized compensation cost related to nonvested restricted stock unit awards granted. The cost is expected to be recognized over a weighted-average period of approximately 1.8 years.
	Employee Stock Purchase Plan
	Under the Employee Stock Purchase Plan, employees purchased 0.3 million shares for the nine months ended September 30, 2014. The weighted average fair value of the discount on the stock purchased was $9.15 per share.
	As of September 30, 2014, a total of 4.9 million of new shares are available to be made issuable by us for this plan.

Earnings_Per_Common_Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2014
Earnings Per Common Share	'
Earnings Per Common Share	'
	12.  Earnings Per Common Share
	The computations of the basic and diluted per share amounts were as follows:
		For the three months ended				For the nine months ended
		September 30,				September 30,
		2014		2013		2014		2013
		(in millions, except per share data)
	Net income	$	252.8	$	259.1	$	896.1	$	685.7
	Subtract:
	Net income attributable to noncontrolling interest	3.9		5.2		30.7		14.7
	Preferred stock dividends	8.2		8.2		24.7		24.7
	Adjustments to redemption amounts of redeemable noncontrolling interests (1)	10.3		—		19.7		—
	Total	$	230.4	$	245.7	$	821	$	646.3
	Weighted-average shares outstanding:
	Basic	294.2		294.9		294.9		294.4
	Dilutive effects:
	Stock options	1.8		1.7		1.7		1.4
	Restricted stock units	1.8		1.7		1.7		1.6
	Performance share awards	0.4		0.3		0.4		0.3
	Diluted	298.2		298.6		298.7		297.7
	Net income per common share:
	Basic	$	0.78	$	0.83	$	2.78	$	2.2
	Diluted	$	0.77	$	0.82	$	2.75	$	2.17
	(1)         During the third quarter of 2013, we identified a classification error of certain of our noncontrolling interests, which had a related impact to earnings per share. See related discussion in Note 8, Stockholders’ Equity — Noncontrolling Interest. The correction of the classification error in the third quarter of 2013 did not significantly impact earnings per share.
	The calculation of diluted earnings per share for the three and nine months ended September 30, 2014 and 2013, excludes the incremental effect related to certain outstanding stock-based compensation grants due to their anti-dilutive effect.

Condensed_Consolidating_Financ

Condensed Consolidating Financial Information	9 Months Ended
	Sep. 30, 2014
Condensed Consolidating Financial Information	'
Condensed Consolidating Financial Information	'
	13.  Condensed Consolidating Financial Information
	Principal Life has established special purpose entities to issue secured medium-term notes. Under the program, the payment obligations of principal and interest on the notes are secured by funding agreements issued by Principal Life. Principal Life’s payment obligations on the funding agreements are fully and unconditionally guaranteed by PFG. All of the outstanding stock of Principal Life is indirectly owned by PFG and PFG is the only guarantor of the payment obligations of the funding agreements.
	The following tables set forth condensed consolidating financial information of (i) PFG, (ii) Principal Life, (iii) Principal Financial Services, Inc. (“PFS”) and all other direct and indirect subsidiaries of PFG on a combined basis and (iv) the eliminations necessary to arrive at the information for PFG on a consolidated basis as of September 30, 2014 and December 31, 2013, and for the nine months ended September 30, 2014 and 2013.
	In presenting the condensed consolidating financial statements, the equity method of accounting has been applied to (i) PFG’s interest in PFS, (ii) Principal Life’s interest in all direct subsidiaries of Principal Life and (iii) PFS’s interest in Principal Life even though all such subsidiaries meet the requirements to be consolidated under U.S. GAAP. Earnings of subsidiaries are, therefore, reflected in the parent’s investment and earnings. All intercompany balances and transactions, including elimination of the parent’s investment in subsidiaries, between PFG, Principal Life and PFS and all other subsidiaries have been eliminated, as shown in the column “Eliminations.” These condensed consolidating financial statements should be read in conjunction with the consolidated financial statements. The financial information may not necessarily be indicative of results of operations, cash flows or financial position had the subsidiaries operated as independent entities.
	Condensed Consolidating Statements of Financial Position
	September 30, 2014
		Principal			Principal Life			Principal Financial						Principal
		Financial			Insurance			Services, Inc. and						Financial
		Group, Inc.			Company			Other Subsidiaries						Group, Inc.
		Parent Only			Only			Combined			Eliminations			Consolidated
		(in millions)
	Assets
	Fixed maturities, available-for-sale	$	—		$	43,630.40		$	6,394.60		$	(397.5	)	$	49,627.50
	Fixed maturities, trading	—			308.7			300.7			—			609.4
	Equity securities, available-for-sale	—			109.4			15.4			—			124.8
	Equity securities, trading	—			0.3			807.3			—			807.6
	Mortgage loans	—			10,842.00			1,245.00			(342.1		)	11,744.90
	Real estate	—			6.9			1,345.20			—			1,352.10
	Policy loans	—			808.4			29.3			—			837.7
	Investment in unconsolidated entities	12,583.20			3,180.20			5,539.40			(20,429.4		)	873.4
	Other investments	9.5			2,723.90			1,396.20			(2,012.1		)	2,117.50
	Cash and cash equivalents	150.7			149.1			833.5			137.5			1,270.80
	Accrued investment income	—			488			58.3			(1.2		)	545.1
	Premiums due and other receivables	—			1,222.90			2,022.70			(2,056.3		)	1,189.30
	Deferred acquisition costs	—			2,739.30			246.1			—			2,985.40
	Property and equipment	—			504.2			85.9			—			590.1
	Goodwill	—			54.3			980.1			—			1,034.40
	Other intangibles	—			26			1,335.40			—			1,361.40
	Separate account assets	—			89,167.70			49,129.00			—			138,296.70
	Other assets	62.4			963.2			2,591.50			(2,562.4		)	1,054.70
	Total assets	$	12,805.80		$	156,924.90		$	74,355.60		$	(27,663.5	)	$	216,422.80
	Liabilities
	Contractholder funds	$	—		$	33,458.00		$	1,527.50		$	(304.7	)	$	34,680.80
	Future policy benefits and claims	—			19,164.80			4,634.90			(400.2		)	23,399.50
	Other policyholder funds	—			747.7			64.9			(0.7		)	811.9
	Short-term debt	—			—			126.3			—			126.3
	Long-term debt	2,448.90			—			409.3			(329.0		)	2,529.20
	Income taxes currently payable	—			—			124.3			(106.2		)	18.1
	Deferred income taxes	—			337			1,055.40			(241.8		)	1,150.60
	Separate account liabilities	—			89,167.70			49,129.00			—			138,296.70
	Other liabilities	40.5			5,725.40			4,587.50			(5,368.8		)	4,984.60
	Total liabilities	2,489.40			148,600.60			61,659.10			(6,751.4		)	205,997.70
	Redeemable noncontrolling interest	—			—			56.1			—			56.1
	Stockholders’ equity
	Series A preferred stock	—			—			—			—			—
	Series B preferred stock	0.1			—			—			—			0.1
	Common stock	4.6			2.5			—			(2.5		)	4.6
	Additional paid-in capital	9,916.90			5,511.30			9,191.90			(14,703.2		)	9,916.90
	Retained earnings	5,945.20			1,978.50			2,983.40			(4,961.9		)	5,945.20
	Accumulated other comprehensive income	380.1			832			407.9			(1,239.9		)	380.1
	Treasury stock, at cost	(5,930.5		)	—			—			—			(5,930.5		)
	Total stockholders’ equity attributable to PFG	10,316.40			8,324.30			12,583.20			(20,907.5		)	10,316.40
	Noncontrolling interest	—			—			57.2			(4.6		)	52.6
	Total stockholders’ equity	10,316.40			8,324.30			12,640.40			(20,912.1		)	10,369.00
	Total liabilities and stockholders’ equity	$	12,805.80		$	156,924.90		$	74,355.60		$	(27,663.5	)	$	216,422.80
	Condensed Consolidating Statements of Financial Position
	December 31, 2013
		Principal			Principal Life			Principal Financial						Principal
		Financial			Insurance			Services, Inc. and						Financial
		Group, Inc.			Company			Other Subsidiaries						Group, Inc.
		Parent Only			Only			Combined			Eliminations			Consolidated
		(in millions)
	Assets
Fixed maturities, available-for-sale	$	—		$	42,794.70		$	6,357.50		$	(395.1	)	$	48,757.10
Fixed maturities, trading	—			245.5			317.6			—			563.1
Equity securities, available-for-sale	—			102.6			7.9			—			110.5
Equity securities, trading	—			0.3			716.6			—			716.9
Mortgage loans	—			10,501.50			1,345.90			(313.8		)	11,533.60
Real estate	—			7.9			1,263.70			—			1,271.60
Policy loans	—			830.1			29.6			—			859.7
Investment in unconsolidated entities	11,956.20			3,396.80			4,891.60			(19,364.6		)	880
Other investments	9.3			1,892.40			1,238.80			(1,076.1		)	2,064.40
Cash and cash equivalents	131.5			1,332.20			894.5			13.6			2,371.80
Accrued investment income	—			474.5			59			(1.4		)	532.1
Premiums due and other receivables	—			1,029.00			1,814.50			(1,602.5		)	1,241.00
Deferred acquisition costs	—			2,848.80			228.2			—			3,077.00
Property and equipment	—			422.1			78.6			—			500.7
Goodwill	—			54.3			1,046.00			—			1,100.30
Other intangibles	—			26.9			1,432.10			—			1,459.00
Separate account assets	—			83,790.20			46,228.20			—			130,018.40
Other assets	59.2			976.9			2,115.30			(2,017.2		)	1,134.20
Total assets	$	12,156.20		$	150,726.70		$	70,065.60		$	(24,757.1	)	$	208,191.40
Liabilities
Contractholder funds	$	—		$	34,918.00		$	1,330.70		$	(290.4	)	$	35,958.30
Future policy benefits and claims	—			18,292.90			4,625.00			(291.7		)	22,626.20
Other policyholder funds	—			705.1			54.2			(0.4		)	758.9
Short-term debt	—			—			150.6			—			150.6
Long-term debt	2,448.80			99.4			367			(313.8		)	2,601.40
Income taxes currently payable	—			—			67.4			(62.2		)	5.2
Deferred income taxes	—			(25.0		)	1,030.10			(181.1		)	824
Separate account liabilities	—			83,790.20			46,228.20			—			130,018.40
Other liabilities	23.2			5,204.80			3,911.80			(3,915.6		)	5,224.20
Total liabilities	2,472.00			142,985.40			57,765.00			(5,055.2		)	198,167.20
Redeemable noncontrolling interest	—			—			247.2			—			247.2
Stockholders’ equity
Series A preferred stock	—			—			—			—			—
Series B preferred stock	0.1			—			—			—			0.1
Common stock	4.6			2.5			—			(2.5		)	4.6
Additional paid-in capital	9,798.90			5,505.00			9,163.70			(14,668.7		)	9,798.90
Retained earnings	5,405.40			1,738.10			2,578.20			(4,316.3		)	5,405.40
Accumulated other comprehensive income	183.2			495.7			214.3			(710.0		)	183.2
Treasury stock, at cost	(5,708.0		)	—			—			—			(5,708.0		)
Total stockholders’ equity attributable to PFG	9,684.20			7,741.30			11,956.20			(19,697.5		)	9,684.20
Noncontrolling interest	—			—			97.2			(4.4		)	92.8
Total stockholders’ equity	9,684.20			7,741.30			12,053.40			(19,701.9		)	9,777.00
Total liabilities and stockholders’ equity	$	12,156.20		$	150,726.70		$	70,065.60		$	(24,757.1	)	$	208,191.40
Condensed Consolidating Statements of Operations
For the nine months ended September 30, 2014
	Principal			Principal Life			Principal Financial						Principal
	Financial			Insurance			Services, Inc. and						Financial
	Group, Inc.			Company			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Revenues
Premiums and other considerations	$	—		$	2,200.50		$	314.3		$	—		$	2,514.80
Fees and other revenues	—			1,407.50			1,451.50			(289.3		)	2,569.70
Net investment income	0.4			1,719.40			1,260.10			(535.8		)	2,444.10
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	—			674.1			(569.1		)	—			105
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	—			27.7			(9.2		)	—			18.5
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	—			(84.5		)	2			—			(82.5		)
Net impairment losses on available-for-sale securities	—			(56.8		)	(7.2		)	—			(64.0		)
Net realized capital gains (losses)	—			617.3			(576.3		)	—			41
Total revenues	0.4			5,944.70			2,449.60			(825.1		)	7,569.60
Expenses
Benefits, claims and settlement expenses	—			3,083.80			534.5			(8.6		)	3,609.70
Dividends to policyholders	—			134.5			—			—			134.5
Operating expenses	106.8			1,624.30			1,156.40			(239.8		)	2,647.70
Total expenses	106.8			4,842.60			1,690.90			(248.4		)	6,391.90
Income (loss) before income taxes	(106.4		)	1,102.10			758.7			(576.7		)	1,177.70
Income taxes (benefits)	(42.7		)	260.6			65.3			(1.6		)	281.6
Equity in the net income (loss) of subsidiaries	929.1			(125.0		)	266.4			(1,070.5		)	—
Net income	865.4			716.5			959.8			(1,645.6		)	896.1
Net income attributable to noncontrolling interest	—			—			30.7			—			30.7
Net income attributable to PFG	865.4			716.5			929.1			(1,645.6		)	865.4
Preferred stock dividends	24.7			—			—			—			24.7
Net income available to common stockholders	$	840.7		$	716.5		$	929.1		$	(1,645.6	)	$	840.7
Net income	$	865.4		$	716.5		$	959.8		$	(1,645.6	)	$	896.1
Other comprehensive income	129.6			334.8			275.7			(550.0		)	190.1
Comprehensive income	$	995		$	1,051.30		$	1,235.50		$	(2,195.6	)	$	1,086.20
Condensed Consolidating Statements of Operations
For the nine months ended September 30, 2013
	Principal			Principal Life			Principal Financial						Principal
	Financial			Insurance			Services, Inc. and						Financial
	Group, Inc.			Company			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Revenues
Premiums and other considerations	$	—		$	1,853.60		$	281.3		$	—		$	2,134.90
Fees and other revenues	—			1,272.30			1,325.80			(257.7		)	2,340.40
Net investment income	0.4			1,775.70			526.5			20.9			2,323.50
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	6.3			(630.7		)	514.8			0.1			(109.5		)
Net other-than-temporary impairment losses on available-for-sale securities	—			(75.4		)	(5.8		)	—			(81.2		)
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	—			11.4			(2.6		)	—			8.8
Net impairment losses on available-for-sale securities	—			(64.0		)	(8.4		)	—			(72.4		)
Net realized capital gains (losses)	6.3			(694.7		)	506.4			0.1			(181.9		)
Total revenues	6.7			4,206.90			2,640.00			(236.7		)	6,616.90
Expenses
Benefits, claims and settlement expenses	—			2,828.80			466.7			(9.1		)	3,286.40
Dividends to policyholders	—			144.3			—			—			144.3
Operating expenses	105.2			1,378.60			1,113.20			(224.9		)	2,372.10
Total expenses	105.2			4,351.70			1,579.90			(234.0		)	5,802.80
Income (loss) before income taxes	(98.5		)	(144.8		)	1,060.10			(2.7		)	814.1
Income taxes (benefits)	(39.4		)	(136.0		)	304			(0.2		)	128.4
Equity in the net income (loss) of subsidiaries	730.1			530.2			(11.2		)	(1,249.1		)	—
Net income	671			521.4			744.9			(1,251.6		)	685.7
Net income attributable to noncontrolling interest	—			—			14.8			(0.1		)	14.7
Net income attributable to PFG	671			521.4			730.1			(1,251.5		)	671
Preferred stock dividends	24.7			—			—			—			24.7
Net income available to common stockholders	$	646.3		$	521.4		$	730.1		$	(1,251.5	)	$	646.3
Net income	$	671		$	521.4		$	744.9		$	(1,251.6	)	$	685.7
Other comprehensive loss	(683.9		)	(438.6		)	(225.6		)	679.8			(668.3		)
Comprehensive income (loss)	$	(12.9	)	$	82.8		$	519.3		$	(571.8	)	$	17.4
Condensed Consolidating Statements of Cash Flows
For the nine months ended September 30, 2014
	Principal			Principal Life			Principal Financial						Principal
	Financial			Insurance			Services, Inc. and						Financial
	Group, Inc.			Company			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Operating activities
Net cash provided by (used in) operating activities	$	(42.3	)	$	1,729.90		$	504.6		$	5.4		$	2,197.60
Investing activities
Available-for-sale securities:
Purchases	—			(5,902.2		)	(705.1		)	11.3			(6,596.0		)
Sales	—			1,559.70			311.8			—			1,871.50
Maturities	—			4,149.40			349.9			—			4,499.30
Mortgage loans acquired or originated	—			(1,620.6		)	(118.1		)	124.5			(1,614.2		)
Mortgage loans sold or repaid	—			1,291.50			137.6			(109.3		)	1,319.80
Real estate acquired	—			(0.6		)	(246.2		)	—			(246.8		)
Net purchases of property and equipment	—			(90.3		)	(27.2		)	—			(117.5		)
Dividends and returns of capital received from unconsolidated entities	517.5			263.5			467.5			(1,248.5		)	—
Net change in other investments	(2.0		)	(83.6		)	34.9			107.3			56.6
Net cash provided by (used in) investing activities	515.5			(433.2		)	205.1			(1,114.7		)	(827.3		)
Financing activities
Issuance of common stock	69.6			(0.2		)	0.2			—			69.6
Acquisition of treasury stock	(222.5		)	—			—			—			(222.5		)
Proceeds from financing element derivatives	—			14.9			—			—			14.9
Payments for financing element derivatives	—			(41.5		)	—			—			(41.5		)
Excess tax benefits from share-based payment arrangements	0.3			3.7			4.6			—			8.6
Purchase of subsidiary shares from noncontrolling interest	—			—			(222.7		)	0.3			(222.4		)
Sale of subsidiary shares to noncontrolling interest	—			—			0.3			(0.3		)	—
Dividends to common stockholders	(276.7		)	—			—			—			(276.7		)
Dividends to preferred stockholders	(24.7		)	—			—			—			(24.7		)
Issuance of long-term debt	—			—			138.9			(102.4		)	36.5
Principal repayments of long-term debt	—			(100.0		)	(87.4		)	87.1			(100.3		)
Net repayments of short-term borrowings	—			—			(20.5		)	—			(20.5		)
Dividends and capital paid to parent	—			(467.5		)	(781.0		)	1,248.50			—
Investment contract deposits	—			3,978.20			206.1			—			4,184.30
Investment contract withdrawals	—			(5,857.3		)	(7.0		)	—			(5,864.3		)
Net decrease in banking operation deposits	—			—			(2.3		)	—			(2.3		)
Other	—			(10.1		)	0.1			—			(10.0		)
Net cash used in financing activities	(454.0		)	(2,479.8		)	(770.7		)	1,233.20			(2,471.3		)
Net increase (decrease) in cash and cash equivalents	19.2			(1,183.1		)	(61.0		)	123.9			(1,101.0		)
Cash and cash equivalents at beginning of period	131.5			1,332.20			894.5			13.6			2,371.80
Cash and cash equivalents at end of period	$	150.7		$	149.1		$	833.5		$	137.5		$	1,270.80
Condensed Consolidating Statements of Cash Flows
For the nine months ended September 30, 2013
	Principal			Principal Life			Principal Financial						Principal
	Financial			Insurance			Services, Inc. and						Financial
	Group, Inc.			Company			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Operating activities
Net cash provided by (used in) operating activities	$	(12.8	)	$	1,412.50		$	(132.2	)	$	130.4		$	1,397.90
Investing activities
Available-for-sale securities:
Purchases	—			(6,094.0		)	(926.7		)	8.4			(7,012.3		)
Sales	—			1,281.40			370.1			(24.8		)	1,626.70
Maturities	—			5,186.50			596.7			—			5,783.20
Mortgage loans acquired or originated	—			(2,226.3		)	(175.6		)	381.9			(2,020.0		)
Mortgage loans sold or repaid	—			1,408.30			583.2			(420.7		)	1,570.80
Real estate acquired	—			—			(59.0		)	—			(59.0		)
Net purchases of property and equipment	—			(20.2		)	(2.5		)	—			(22.7		)
Purchases of interests in subsidiaries, net of cash acquired	—			—			(1,268.3		)	—			(1,268.3		)
Dividends and returns of capital received from unconsolidated entities	169.3			157.9			169.3			(496.5		)	—
Net change in other investments	(3.2		)	76.1			(128.4		)	24.3			(31.2		)
Net cash provided by (used in) investing activities	166.1			(230.3		)	(841.2		)	(527.4		)	(1,432.8		)
Financing activities
Issuance of common stock	80.2			—			—			—			80.2
Acquisition of treasury stock	(153.4		)	—			—			—			(153.4		)
Proceeds from financing element derivatives	—			46.7			—			—			46.7
Payments for financing element derivatives	—			(36.9		)	—			—			(36.9		)
Excess tax benefits from share-based payment arrangements	—			2.5			6.1			—			8.6
Purchase of subsidiary shares from noncontrolling interest	—			—			(51.4		)	—			(51.4		)
Sale of subsidiary shares to noncontrolling interest	—			—			31.8			—			31.8
Dividends to common stockholders	(211.7		)	—			—			—			(211.7		)
Dividends to preferred stockholders	(24.7		)	—			—			—			(24.7		)
Issuance of long-term debt	—			—			24.1			—			24.1
Principal repayments of long-term debt	—			—			(197.8		)	(14.4		)	(212.2		)
Net proceeds from short-term borrowings	—			—			131.6			—			131.6
Dividends and capital paid to parent	—			(169.3		)	(327.2		)	496.5			—
Investment contract deposits	—			4,985.40			284.8			—			5,270.20
Investment contract withdrawals	—			(7,051.1		)	(4.5		)	—			(7,055.6		)
Net decrease in banking operation deposits	—			—			(276.2		)	—			(276.2		)
Other	—			(6.3		)	—			—			(6.3		)
Net cash used in financing activities	(309.6		)	(2,229.0		)	(378.7		)	482.1			(2,435.2		)
Net decrease in cash and cash equivalents	(156.3		)	(1,046.8		)	(1,352.1		)	85.1			(2,470.1		)
Cash and cash equivalents at beginning of period	207.1			1,698.40			2,286.90			(15.2		)	4,177.20
Cash and cash equivalents at end of period	$	50.8		$	651.6		$	934.8		$	69.9		$	1,707.10
On May 7, 2014, our shelf registration statement was filed with the SEC and became effective. The shelf registration replaces the shelf registration that had been in effect since May 2011. Under our current shelf registration, we have the ability to issue in unlimited amounts, unsecured senior debt securities or subordinated debt securities, junior subordinated debt, preferred stock, common stock, warrants, depository shares, stock purchase contracts and stock purchase units of PFG, trust preferred securities of three subsidiary trusts and guarantees by PFG of these trust preferred securities. Our wholly owned subsidiary, PFS, may guarantee, fully and unconditionally or otherwise, our obligations with respect to any non-convertible securities, other than common stock, described in the shelf registration.
The following tables set forth condensed consolidating financial information of (i) PFG, (ii) PFS, (iii) Principal Life and all other direct and indirect subsidiaries of PFG on a combined basis and (iv) the eliminations necessary to arrive at the information for PFG on a consolidated basis as of September 30, 2014 and December 31, 2013, and for the nine months ended September 30, 2014 and 2013.
In presenting the condensed consolidating financial statements, the equity method of accounting has been applied to (i) PFG’s interest in PFS and (ii) PFS’s interest in Principal Life and all other subsidiaries, where applicable, even though all such subsidiaries meet the requirements to be consolidated under U.S. GAAP. Earnings of subsidiaries are, therefore, reflected in the parent’s investment and earnings. All intercompany balances and transactions, including elimination of the parent’s investment in subsidiaries, between PFG, PFS and Principal Life and all other subsidiaries have been eliminated, as shown in the column “Eliminations.” These condensed consolidating financial statements should be read in conjunction with the consolidated financial statements. The financial information may not necessarily be indicative of results of operations, cash flows or financial position had the subsidiaries operated as independent entities.
Condensed Consolidating Statements of Financial Position
September 30, 2014
							Principal Life
	Principal			Principal			Insurance Company						Principal
	Financial			Financial			and Other						Financial
	Group, Inc.			Services, Inc.			Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Assets
Fixed maturities, available-for-sale	$	—		$	—		$	49,627.50		$	—		$	49,627.50
Fixed maturities, trading	—			—			609.4			—			609.4
Equity securities, available-for-sale	—			—			124.8			—			124.8
Equity securities, trading	—			—			807.6			—			807.6
Mortgage loans	—			—			11,744.90			—			11,744.90
Real estate	—			—			1,352.10			—			1,352.10
Policy loans	—			—			837.7			—			837.7
Investment in unconsolidated entities	12,583.20			12,103.70			841.4			(24,654.9		)	873.4
Other investments	9.5			179			1,929.00			—			2,117.50
Cash and cash equivalents	150.7			413			1,196.40			(489.3		)	1,270.80
Accrued investment income	—			—			545.1			—			545.1
Premiums due and other receivables	—			0.6			1,188.30			0.4			1,189.30
Deferred acquisition costs	—			—			2,985.40			—			2,985.40
Property and equipment	—			—			590.1			—			590.1
Goodwill	—			—			1,034.40			—			1,034.40
Other intangibles	—			—			1,361.40			—			1,361.40
Separate account assets	—			—			138,296.70			—			138,296.70
Other assets	62.4			152.9			1,136.60			(297.2		)	1,054.70
Total assets	$	12,805.80		$	12,849.20		$	216,208.80		$	(25,441.0	)	$	216,422.80
Liabilities
Contractholder funds	$	—		$	—		$	34,680.80		$	—		$	34,680.80
Future policy benefits and claims	—			—			23,399.50			—			23,399.50
Other policyholder funds	—			—			811.9			—			811.9
Short-term debt	—			—			325.4			(199.1		)	126.3
Long-term debt	2,448.90			—			80.3			—			2,529.20
Income taxes currently payable	—			16			83.9			(81.8		)	18.1
Deferred income taxes	—			—			1,361.60			(211.0		)	1,150.60
Separate account liabilities	—			—			138,296.70			—			138,296.70
Other liabilities	40.5			250			4,956.30			(262.2		)	4,984.60
Total liabilities	2,489.40			266			203,996.40			(754.1		)	205,997.70
Redeemable noncontrolling interest	—			—			56.1			—			56.1
Stockholders’ equity
Series A preferred stock	—			—			—			—			—
Series B preferred stock	0.1			—			—			—			0.1
Common stock	4.6			—			17.8			(17.8		)	4.6
Additional paid-in capital	9,916.90			9,191.90			9,284.20			(18,476.1		)	9,916.90
Retained earnings	5,945.20			2,983.40			2,450.20			(5,433.6		)	5,945.20
Accumulated other comprehensive income	380.1			407.9			353.5			(761.4		)	380.1
Treasury stock, at cost	(5,930.5		)	—			(2.0		)	2			(5,930.5		)
Total stockholders’ equity attributable to PFG	10,316.40			12,583.20			12,103.70			(24,686.9		)	10,316.40
Noncontrolling interest	—			—			52.6			—			52.6
Total stockholders’ equity	10,316.40			12,583.20			12,156.30			(24,686.9		)	10,369.00
Total liabilities and stockholders’ equity	$	12,805.80		$	12,849.20		$	216,208.80		$	(25,441.0	)	$	216,422.80
Condensed Consolidating Statements of Financial Position
December 31, 2013
							Principal Life
	Principal			Principal			Insurance Company						Principal
	Financial			Financial			and Other						Financial
	Group, Inc.			Services, Inc.			Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Assets
Fixed maturities, available-for-sale	$	—		$	—		$	48,757.10		$	—		$	48,757.10
Fixed maturities, trading	—			—			563.1			—			563.1
Equity securities, available-for-sale	—			—			110.5			—			110.5
Equity securities, trading	—			—			716.9			—			716.9
Mortgage loans	—			—			11,533.60			—			11,533.60
Real estate	—			—			1,271.60			—			1,271.60
Policy loans	—			—			859.7			—			859.7
Investment in unconsolidated entities	11,956.20			11,647.60			879.8			(23,603.6		)	880
Other investments	9.3			72.7			1,982.50			(0.1		)	2,064.40
Cash and cash equivalents	131.5			688.7			2,384.00			(832.4		)	2,371.80
Accrued investment income	—			—			532.1			—			532.1
Premiums due and other receivables	—			0.1			2,330.40			(1,089.5		)	1,241.00
Deferred acquisition costs	—			—			3,077.00			—			3,077.00
Property and equipment	—			—			500.7			—			500.7
Goodwill	—			—			1,100.30			—			1,100.30
Other intangibles	—			—			1,459.00			—			1,459.00
Separate account assets	—			—			130,018.40			—			130,018.40
Other assets	59.2			94.8			1,181.00			(200.8		)	1,134.20
Total assets	$	12,156.20		$	12,503.90		$	209,257.70		$	(25,726.4	)	$	208,191.40
Liabilities
Contractholder funds	$	—		$	—		$	35,958.30		$	—		$	35,958.30
Future policy benefits and claims	—			—			22,626.20			—			22,626.20
Other policyholder funds	—			—			758.9			—			758.9
Short-term debt	—			—			443			(292.4		)	150.6
Long-term debt	2,448.80			—			1,236.90			(1,084.3		)	2,601.40
Income taxes currently payable	—			2.8			44.7			(42.3		)	5.2
Deferred income taxes	—			—			979.6			(155.6		)	824
Separate account liabilities	—			—			130,018.40			—			130,018.40
Other liabilities	23.2			544.9			5,204.10			(548.0		)	5,224.20
Total liabilities	2,472.00			547.7			197,270.10			(2,122.6		)	198,167.20
Redeemable noncontrolling interest	—			—			247.2			—			247.2
Stockholders’ equity
Series A preferred stock	—			—			—			—			—
Series B preferred stock	0.1			—			—			—			0.1
Common stock	4.6			—			17.8			(17.8		)	4.6
Additional paid-in capital	9,798.90			9,163.70			9,057.10			(18,220.8		)	9,798.90
Retained earnings	5,405.40			2,578.20			2,387.20			(4,965.4		)	5,405.40
Accumulated other comprehensive income	183.2			214.3			187.5			(401.8		)	183.2
Treasury stock, at cost	(5,708.0		)	—			(2.0		)	2			(5,708.0		)
Total stockholders’ equity attributable to PFG	9,684.20			11,956.20			11,647.60			(23,603.8		)	9,684.20
Noncontrolling interest	—			—			92.8			—			92.8
Total stockholders’ equity	9,684.20			11,956.20			11,740.40			(23,603.8		)	9,777.00
Total liabilities and stockholders’ equity	$	12,156.20		$	12,503.90		$	209,257.70		$	(25,726.4	)	$	208,191.40
Condensed Consolidating Statements of Operations
For the nine months ended September 30, 2014
							Principal Life
	Principal			Principal			Insurance						Principal
	Financial			Financial			Company and						Financial
	Group, Inc.			Services, Inc.			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Revenues
Premiums and other considerations	$	—		$	—		$	2,514.80		$	—		$	2,514.80
Fees and other revenues	—			0.3			2,569.40			—			2,569.70
Net investment income	0.4			0.5			2,443.20			—			2,444.10
Net realized capital gains, excluding impairment losses on available-for-sale securities	—			—			105			—			105
Net other-than-temporary impairment recoveries on available-for-sale securities	—			—			18.5			—			18.5
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified from other comprehensive income	—			—			(82.5		)	—			(82.5		)
Net impairment losses on available-for-sale securities	—			—			(64.0		)	—			(64.0		)
Net realized capital gains	—			—			41			—			41
Total revenues	0.4			0.8			7,568.40			—			7,569.60
Expenses
Benefits, claims and settlement expenses	—			—			3,609.70			—			3,609.70
Dividends to policyholders	—			—			134.5			—			134.5
Operating expenses	106.8			3.1			2,537.80			—			2,647.70
Total expenses	106.8			3.1			6,282.00			—			6,391.90
Income (loss) before income taxes	(106.4		)	(2.3		)	1,286.40			—			1,177.70
Income taxes (benefits)	(42.7		)	(3.2		)	327.5			—			281.6
Equity in the net income of subsidiaries	929.1			928.2			—			(1,857.3		)	—
Net income	865.4			929.1			958.9			(1,857.3		)	896.1
Net income attributable to noncontrolling interest	—			—			30.7			—			30.7
Net income attributable to PFG	865.4			929.1			928.2			(1,857.3		)	865.4
Preferred stock dividends	24.7			—			—			—			24.7
Net income available to common stockholders	$	840.7		$	929.1		$	928.2		$	(1,857.3	)	$	840.7
Net income	$	865.4		$	929.1		$	958.9		$	(1,857.3	)	$	896.1
Other comprehensive income	129.6			183.5			163.9			(286.9		)	190.1
Comprehensive income	$	995		$	1,112.60		$	1,122.80		$	(2,144.2	)	$	1,086.20
Condensed Consolidating Statements of Operations
For the nine months ended September 30, 2013
							Principal Life
	Principal			Principal			Insurance						Principal
	Financial			Financial			Company and						Financial
	Group, Inc.			Services, Inc.			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Revenues
Premiums and other considerations	$	—		$	—		$	2,134.90		$	—		$	2,134.90
Fees and other revenues	—			0.9			2,357.80			(18.3		)	2,340.40
Net investment income	0.4			1.1			2,321.80			0.2			2,323.50
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	6.3			2.6			(118.4		)	—			(109.5		)
Net other-than-temporary impairment losses on available-for-sale securities	—			—			(81.2		)	—			(81.2		)
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to other comprehensive income	—			—			8.8			—			8.8
Net impairment losses on available-for-sale securities	—			—			(72.4		)	—			(72.4		)
Net realized capital gains (losses)	6.3			2.6			(190.8		)	—			(181.9		)
Total revenues	6.7			4.6			6,623.70			(18.1		)	6,616.90
Expenses
Benefits, claims and settlement expenses	—			—			3,286.40			—			3,286.40
Dividends to policyholders	—			—			144.3			—			144.3
Operating expenses	105.2			8.4			2,276.60			(18.1		)	2,372.10
Total expenses	105.2			8.4			5,707.30			(18.1		)	5,802.80
Income (loss) before income taxes	(98.5		)	(3.8		)	916.4			—			814.1
Income taxes (benefits)	(39.4		)	(2.2		)	170			—			128.4
Equity in the net income of subsidiaries	730.1			731.7			—			(1,461.8		)	—
Net income	671			730.1			746.4			(1,461.8		)	685.7
Net income attributable to noncontrolling interest	—			—			14.7			—			14.7
Net income attributable to PFG	671			730.1			731.7			(1,461.8		)	671
Preferred stock dividends	24.7			—			—			—			24.7
Net income available to common stockholders	$	646.3		$	730.1		$	731.7		$	(1,461.8	)	$	646.3
Net income	$	671		$	730.1		$	746.4		$	(1,461.8	)	$	685.7
Other comprehensive loss	(683.9		)	(671.8		)	(679.2		)	1,366.60			(668.3		)
Comprehensive income (loss)	$	(12.9	)	$	58.3		$	67.2		$	(95.2	)	$	17.4
Condensed Consolidating Statements of Cash Flows
For the nine months ended September 30, 2014
							Principal Life
	Principal			Principal			Insurance						Principal
	Financial			Financial			Company and						Financial
	Group, Inc.			Services, Inc.			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Operating activities
Net cash provided by (used in) operating activities	$	(42.3	)	$	(373.5	)	$	2,335.40		$	278		$	2,197.60
Investing activities
Available-for-sale securities:
Purchases	—			—			(6,596.0		)	—			(6,596.0		)
Sales	—			—			1,871.50			—			1,871.50
Maturities	—			—			4,499.30			—			4,499.30
Mortgage loans acquired or originated	—			—			(1,614.2		)	—			(1,614.2		)
Mortgage loans sold or repaid	—			—			1,319.80			—			1,319.80
Real estate acquired	—			—			(246.8		)	—			(246.8		)
Net purchases of property and equipment	—			—			(117.5		)	—			(117.5		)
Dividends and returns of capital received from unconsolidated entities	517.5			714			—			(1,231.5		)	—
Net change in other investments	(2.0		)	(98.7		)	185.2			(27.9		)	56.6
Net cash provided by (used in) investing activities	515.5			615.3			(698.7		)	(1,259.4		)	(827.3		)
Financing activities
Issuance of common stock	69.6			—			—			—			69.6
Acquisition of treasury stock	(222.5		)	—			—			—			(222.5		)
Proceeds from financing element derivatives	—			—			14.9			—			14.9
Payments for financing element derivatives	—			—			(41.5		)	—			(41.5		)
Excess tax benefits from share-based payment arrangements	0.3			—			8.3			—			8.6
Purchase of subsidiary shares from noncontrolling interest	—			—			(222.4		)	—			(222.4		)
Dividends to common stockholders	(276.7		)	—			—			—			(276.7		)
Dividends to preferred stockholders	(24.7		)	—			—			—			(24.7		)
Issuance of long-term debt	—			—			36.5			—			36.5
Principal repayments of long-term debt	—			—			(100.3		)	—			(100.3		)
Net repayments of short-term borrowings	—			—			(113.5		)	93			(20.5		)
Dividends and capital paid to parent	—			(517.5		)	(714.0		)	1,231.50			—
Investment contract deposits	—			—			4,184.30			—			4,184.30
Investment contract withdrawals	—			—			(5,864.3		)	—			(5,864.3		)
Net decrease in banking operation deposits	—			—			(2.3		)	—			(2.3		)
Other	—			—			(10.0		)	—			(10.0		)
Net cash used in financing activities	(454.0		)	(517.5		)	(2,824.3		)	1,324.50			(2,471.3		)
Net increase (decrease) in cash and cash equivalents	19.2			(275.7		)	(1,187.6		)	343.1			(1,101.0		)
Cash and cash equivalents at beginning of period	131.5			688.7			2,384.00			(832.4		)	2,371.80
Cash and cash equivalents at end of period	$	150.7		$	413		$	1,196.40		$	(489.3	)	$	1,270.80
Condensed Consolidating Statements of Cash Flows
For the nine months ended September 30, 2013
							Principal Life
	Principal			Principal			Insurance						Principal
	Financial			Financial			Company and						Financial
	Group, Inc.			Services, Inc.			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Operating activities
Net cash provided by (used in) operating activities	$	(12.8	)	$	870.9		$	1,473.40		$	(933.6	)	$	1,397.90
Investing activities
Available-for-sale securities:
Purchases	—			—			(7,012.3		)	—			(7,012.3		)
Sales	—			—			1,626.70			—			1,626.70
Maturities	—			—			5,783.20			—			5,783.20
Mortgage loans acquired or originated	—			—			(2,020.0		)	—			(2,020.0		)
Mortgage loans sold or repaid	—			—			1,570.80			—			1,570.80
Real estate acquired	—			—			(59.0		)	—			(59.0		)
Net purchases of property and equipment	—			—			(22.7		)	—			(22.7		)
Purchases of interests in subsidiaries, net of cash acquired	—			—			(1,268.3		)	—			(1,268.3		)
Dividends and returns of capital received from (contributions to) unconsolidated entities	169.3			(809.2		)	—			639.9			—
Net change in other investments	(3.2		)	(13.9		)	(14.1		)	—			(31.2		)
Net cash provided by (used in) investing activities	166.1			(823.1		)	(1,415.7		)	639.9			(1,432.8		)
Financing activities
Issuance of common stock	80.2			—			—			—			80.2
Acquisition of treasury stock	(153.4		)	—			—			—			(153.4		)
Proceeds from financing element derivatives	—			—			46.7			—			46.7
Payments for financing element derivatives	—			—			(36.9		)	—			(36.9		)
Excess tax benefits from share-based payment arrangements	—			—			8.6			—			8.6
Purchase of subsidiary shares from noncontrolling interest	—			—			(51.4		)	—			(51.4		)
Sale of subsidiary shares to noncontrolling interest	—			—			31.8			—			31.8
Dividends to common stockholders	(211.7		)	—			—			—			(211.7		)
Dividends to preferred stockholders	(24.7		)	—			—			—			(24.7		)
Issuance of long-term debt	—			—			1,108.40			(1,084.3		)	24.1
Principal repayments of long-term debt	—			—			(212.2		)	—			(212.2		)
Net proceeds from (repayments of) short-term borrowings	—			—			(2,113.2		)	2,244.80			131.6
Dividends and capital received from (paid to) parent	—			(169.3		)	809.2			(639.9		)	—
Investment contract deposits	—			—			5,270.20			—			5,270.20
Investment contract withdrawals	—			—			(7,055.6		)	—			(7,055.6		)
Net decrease in banking operation deposits	—			—			(276.2		)	—			(276.2		)
Other	—			—			(6.3		)	—			(6.3		)
Net cash used in financing activities	(309.6		)	(169.3		)	(2,476.9		)	520.6			(2,435.2		)
Net decrease in cash and cash equivalents	(156.3		)	(121.5		)	(2,419.2		)	226.9			(2,470.1		)
Cash and cash equivalents at beginning of period	207.1			612.5			4,241.30			(883.7		)	4,177.20
Cash and cash equivalents at end of period	$	50.8		$	491		$	1,822.10		$	(656.8	)	$	1,707.10

Nature_of_Operations_and_Signi1

Nature of Operations and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Nature of Operations and Significant Accounting Policies	'
Separate Accounts - Policy	'
	Separate Accounts
	The separate accounts are legally segregated and are not subject to the claims that arise out of any of our other business. The client, rather than us, directs the investments and bears the investment risk of these funds. The separate account assets represent the fair value of funds that are separately administered by us for contracts with equity, real estate and fixed income investments and are presented as a summary total within the consolidated statements of financial position. An equivalent amount is reported as separate account liabilities, which represent the obligation to return the monies to the client. We receive fees for mortality, withdrawal and expense risks, as well as administrative, maintenance and investment advisory services that are included in the consolidated statements of operations. Net deposits, net investment income and realized and unrealized capital gains and losses of the separate accounts are not reflected in the consolidated statements of operations. Separate account assets and separate account liabilities include certain non-domestic retirement accumulation products where the segregated funds and associated obligation to the client are consolidated within our financial statements. We have determined that summary totals are the most meaningful presentation for these funds.
	At September 30, 2014 and December 31, 2013, the separate account assets include a separate account valued at $216.0 million and $223.1 million, respectively, which primarily includes shares of our stock that were allocated and issued to eligible participants of qualified employee benefit plans administered by us as part of the policy credits issued under our 2001 demutualization. These shares are included in both basic and diluted earnings per share calculations. In the consolidated statements of financial position, the separate account shares are recorded at fair value and are reported as separate account assets with a corresponding separate account liability to eligible participants of the qualified plan. Changes in fair value of the separate account shares are reflected in both the separate account assets and separate account liabilities and do not impact our results of operations.

Variable_Interest_Entities_Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2014
Variable Interest Entities	'
Carrying Amounts of Assets and Liabilities of Consolidated Variable Interest Entities (Table)	'
				Collateralized
				private				Mandatory
		Grantor		investment				retirement
		trusts		vehicle		CMBS		savings		Real estate		Total
						(in millions)
	September 30, 2014
	Fixed maturities, available-for-sale	$	287.2	$	—	$	—	$	—	$	—	$	287.2
	Fixed maturities, trading	—		100.4		—		—		—		100.4
	Equity securities, trading	—		—		—		349.4		—		349.4
	Real estate	—		—		—		—		276.2		276.2
	Other investments	—		—		41.9		—		4.3		46.2
	Cash	—		—		—		—		6.2		6.2
	Accrued investment income	0.4		—		0.2		—		1.5		2.1
	Separate account assets	—		—		—		35,079.90		—		35,079.90
	Other assets	—		—		—		—		0.2		0.2
	Total assets	$	287.6	$	100.4	$	42.1	$	35,429.30	$	288.4	$	36,147.80
	Long-term debt	$	—	$	—	$	—	$	—	$	74.9	$	74.9
	Deferred income taxes	1.6		—		—		—		—		1.6
	Separate account liabilities	—		—		—		35,079.90		—		35,079.90
	Other liabilities (1)	242		86.9		4.9		—		15.7		349.5
	Total liabilities	$	243.6	$	86.9	$	4.9	$	35,079.90	$	90.6	$	35,505.90
	December 31, 2013
	Fixed maturities, available-for-sale	$	272	$	—	$	—	$	—	$	—	$	272
	Fixed maturities, trading	—		110.4		—		—		—		110.4
	Equity securities, trading	—		—		—		327.2		—		327.2
	Real estate	—		—		—		—		266.3		266.3
	Other investments	—		—		68.1		—		—		68.1
	Cash	—		—		—		—		12		12
	Accrued investment income	0.3		—		0.6		—		1.1		2
	Separate account assets	—		—		—		32,824.70		—		32,824.70
	Other assets	—		—		—		—		0.1		0.1
	Total assets	$	272.3	$	110.4	$	68.7	$	33,151.90	$	279.5	$	33,882.80
	Long-term debt	$	—	$	—	$	—	$	—	$	47.7	$	47.7
	Deferred income taxes	1.5		—		—		—		—		1.5
	Separate account liabilities	—		—		—		32,824.70		—		32,824.70
	Other liabilities (1)	217.2		93.8		31.4		—		20		362.4
	Total liabilities	$	218.7	$	93.8	$	31.4	$	32,824.70	$	67.7	$	33,236.30
	(1)            Grantor trusts contain an embedded derivative of a forecasted transaction to deliver the underlying securities; the collateralized private investment vehicle includes derivative liabilities and an obligation to redeem notes at maturity or termination of the trust.
Asset Carrying Value and Maximum Loss Exposure of Unconsolidated Variable Interest Entities (Table)	'
				Maximum exposure to
		Asset carrying value		loss (1)
		(in millions)
	September 30, 2014
	Fixed maturities, available-for-sale:
	Corporate	$	493.4	$	393.9
	Residential mortgage-backed pass-through securities	2,809.00		2,714.50
	Commercial mortgage-backed securities	4,012.30		3,925.80
	Collateralized debt obligations	480.8		493.5
	Other debt obligations	4,414.40		4,385.00
	Fixed maturities, trading:
	Residential mortgage-backed pass-through securities	37.3		37.3
	Commercial mortgage-backed securities	1.4		1.4
	Collateralized debt obligations	38.9		38.9
	Other debt obligations	0.5		0.5
	Other investments:
	Other limited partnership interests	154.5		154.5
	December 31, 2013
	Fixed maturities, available-for-sale:
	Corporate	$	523.4	$	448.2
	Residential mortgage-backed pass-through securities	2,845.20		2,799.10
	Commercial mortgage-backed securities	4,026.40		4,078.00
	Collateralized debt obligations	363.4		391.9
	Other debt obligations	4,167.80		4,157.50
	Fixed maturities, trading:
	Residential mortgage-backed pass-through securities	47.5		47.5
	Commercial mortgage-backed securities	1.8		1.8
	Collateralized debt obligations	59.6		59.6
	Other debt obligations	1.2		1.2
	Other investments:
	Other limited partnership interests	123.5		123.5
	(1)         Our risk of loss is limited to our initial investment measured at amortized cost for fixed maturities, available-for-sale and other investments. Our risk of loss is limited to our investment measured at fair value for our fixed maturities, trading.

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2014
Investments	'
Fixed Maturities and Equity Securities Available-for-Sale (Table)	'
															Other-than-
						Gross			Gross						temporary
			Amortized			unrealized			unrealized						impairments in
			cost			gains			losses			Fair value			AOCI (1)
			(in millions)
	September 30, 2014
	Fixed maturities, available-for-sale:
	U.S. government and agencies		$	882.2		$	18.3		$	8.4		$	892.1		$	—
	Non-U.S. governments		736.7			168.9			0.9			904.7			—
	States and political subdivisions		3,875.80			233.9			15.7			4,094.00			—
	Corporate		29,762.30			2,414.40			156.5			32,020.20			19.4
	Residential mortgage-backed pass-through securities		2,714.50			109.8			15.3			2,809.00			—
	Commercial mortgage-backed securities		3,925.80			164.7			78.2			4,012.30			105.5
	Collateralized debt obligations		493.5			7			19.7			480.8			1.2
	Other debt obligations		4,385.00			55.7			26.3			4,414.40			68.8
	Total fixed maturities, available-for-sale		$	46,775.80		$	3,172.70		$	321		$	49,627.50		$	194.9
	Total equity securities, available-for-sale		$	126.8		$	8.4		$	10.4		$	124.8
	December 31, 2013
	Fixed maturities, available-for-sale:
	U.S. government and agencies		$	818.2		$	12.7		$	50.4		$	780.5		$	—
	Non-U.S. governments		853.2			148.8			5.2			996.8			—
	States and political subdivisions		3,622.80			120.9			85.7			3,658.00			—
	Corporate		30,280.60			1,958.80			320.4			31,919.00			17.1
	Residential mortgage-backed pass-through securities		2,799.10			92.8			46.7			2,845.20			—
	Commercial mortgage-backed securities		4,078.00			170.6			222.2			4,026.40			183.4
	Collateralized debt obligations		391.9			6			34.5			363.4			0.7
	Other debt obligations		4,157.50			51.8			41.5			4,167.80			76.3
	Total fixed maturities, available-for-sale		$	47,001.30		$	2,562.40		$	806.6		$	48,757.10		$	277.5
	Total equity securities, available-for-sale		$	113.8		$	10		$	13.3		$	110.5
	(1)         Excludes $186.6 million and $148.6 million as of September 30, 2014 and December 31, 2013, respectively, of net unrealized gains on impaired fixed maturities, available-for-sale related to changes in fair value subsequent to the impairment date, which are included in gross unrealized gains and gross unrealized losses.
Fixed Maturities Available-for-Sale by Contractual Maturity (Table)	'
			Amortized cost			Fair value
			(in millions)
	Due in one year or less		$	2,886.80		$	2,924.30
	Due after one year through five years		12,618.50			13,221.60
	Due after five years through ten years		8,167.60			8,694.80
	Due after ten years		11,584.10			13,070.30
	Subtotal		35,257.00			37,911.00
	Mortgage-backed and other asset-backed securities		11,518.80			11,716.50
	Total		$	46,775.80		$	49,627.50
Net Realized Capital Gains and Losses (Table)	'
			For the three months ended						For the nine months ended
			September 30,						September 30,
			2014			2013			2014			2013
			(in millions)
	Fixed maturities, available-for-sale:
	Gross gains		$	9.6		$	5.8		$	73.8		$	27.6
	Gross losses		(13.6		)	(18.2		)	(36.6		)	(98.6		)
	Other-than-temporary impairment losses reclassified to (from) OCI		(14.6		)	(9.3		)	(82.5		)	8.8
	Hedging, net		(21.5		)	(9.6		)	(20.0		)	(99.4		)
	Fixed maturities, trading		9.5			2.1			32			(4.1		)
	Equity securities, available-for-sale:
	Gross gains		—			0.7			5.8			0.8
	Gross losses		(0.3		)	—			(0.3		)	(0.1		)
	Equity securities, trading		9.1			0.1			18.7			11.6
	Mortgage loans		(12.0		)	(3.3		)	(10.6		)	(20.3		)
	Derivatives		(2.0		)	(34.8		)	1.9			(4.8		)
	Other		(10.6		)	15.6			58.8			(3.4		)
	Net realized capital gains (losses)		$	(46.4	)	$	(50.9	)	$	41		$	(181.9	)
Other-Than-Temporary Impairment Losses, Net of Recoveries (Table)	'
			For the three months ended						For the nine months ended
			September 30,						September 30,
			2014			2013			2014			2013
			(in millions)
	Fixed maturities, available-for-sale		$	(7.1	)	$	(11.9	)	$	13		$	(81.1	)
	Equity securities, available-for-sale		(0.2		)	—			5.5			(0.1		)
	Total other-than-temporary impairment losses, net of recoveries from the sale of previously impaired securities		(7.3		)	(11.9		)	18.5			(81.2		)
	Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) OCI (1)		(14.6		)	(9.3		)	(82.5		)	8.8
	Net impairment losses on available-for-sale securities		$	(21.9	)	$	(21.2	)	$	(64.0	)	$	(72.4	)
	-1	Represents the net impact of (a) gains resulting from reclassification of noncredit impairment losses for fixed maturities with bifurcated OTTI from net realized capital gains (losses) to OCI and (b) losses resulting from reclassification of previously recognized noncredit impairment losses from OCI to net realized capital gains (losses) for fixed maturities with bifurcated OTTI that had additional credit losses or fixed maturities that previously had bifurcated OTTI that have now been sold or are intended to be sold.
Other-Than-Temporary Impairment, Credit Losses Recognized in Earnings (Table)	'
			For the three months ended						For the nine months ended
			September 30,						September 30,
			2014			2013			2014			2013
			(in millions)
	Beginning balance		$	(185.7	)	$	(301.5	)	$	(235.4	)	$	(335.2	)
	Credit losses for which an other-than-temporary impairment was not previously recognized		(2.2		)	(4.9		)	(6.1		)	(11.1		)
	Credit losses for which an other-than-temporary impairment was previously recognized		(21.0		)	(18.9		)	(65.5		)	(54.0		)
	Reduction for credit losses previously recognized on fixed maturities now sold, paid down or intended to be sold		18			14.6			112			83.1
	Net reduction for positive changes in cash flows expected to be collected and amortization (1)		1.5			2.7			5.6			9.2
	Ending balance		$	(189.4	)	$	(308.0	)	$	(189.4	)	$	(308.0	)
	(1)   Amounts are recognized in net investment income.
Gross Unrealized Losses for Fixed Maturities and Equity Securities (Table)	'
			September 30, 2014
			Less than						Greater than or
			twelve months						equal to twelve months						Total
						Gross						Gross					Gross
			Fair			unrealized			Fair			unrealized			Fair		unrealized
			value			losses			value			losses			value		losses
			(in millions)
	Fixed maturities, available-for-sale:
	U.S. government and agencies		$	258.7		$	1.2		$	210.5		$	7.2		$	469.2	$	8.4
	Non-U.S. governments		36			0.6			11.6			0.3			47.6		0.9
	States and political subdivisions		169.8			1.3			359.5			14.4			529.3		15.7
	Corporate		2,489.20			24.9			1,459.50			131.6			3,948.70		156.5
	Residential mortgage-backed pass-through securities		175.7			0.7			504.1			14.6			679.8		15.3
	Commercial mortgage-backed securities		315.1			3			472.4			75.2			787.5		78.2
	Collateralized debt obligations		147.5			1.6			82.9			18.1			230.4		19.7
	Other debt obligations		867.9			3.3			486.2			23			1,354.10		26.3
	Total fixed maturities, available-for-sale		$	4,459.90		$	36.6		$	3,586.70		$	284.4		$	8,046.60	$	321
	Total equity securities, available-for-sale		$	—		$	—		$	50.9		$	10.4		$	50.9	$	10.4
			December 31, 2013
			Less than						Greater than or
			twelve months						equal to twelve months						Total
						Gross						Gross					Gross
			Fair			unrealized			Fair			unrealized			Fair		unrealized
			value			losses			value			losses			value		losses
			(in millions)
	Fixed maturities, available-for-sale:
	U.S. government and agencies		$	526.8		$	49.6		$	9.2		$	0.8		$	536	$	50.4
	Non-U.S. governments		78.1			5.1			5.8			0.1			83.9		5.2
	States and political subdivisions		1,338.60			75.3			46.1			10.4			1,384.70		85.7
	Corporate		4,087.90			155.4			1,278.10			165			5,366.00		320.4
	Residential mortgage-backed pass- through securities		1,150.30			38.2			85.9			8.5			1,236.20		46.7
	Commercial mortgage-backed securities		683.7			15.3			495.6			206.9			1,179.30		222.2
	Collateralized debt obligations		88.8			1.4			47.4			33.1			136.2		34.5
	Other debt obligations		1,359.00			16.1			287.9			25.4			1,646.90		41.5
	Total fixed maturities, available-for-sale		$	9,313.20		$	356.4		$	2,256.00		$	450.2		$	11,569.20	$	806.6
	Total equity securities, available-for-sale		$	16.7		$	0.3		$	48.3		$	13		$	65	$	13.3
Net Unrealized Gains and Losses on Available-for-Sale Securities and Derivative Instruments (Table)	'
			September 30, 2014			December 31, 2013
			(in millions)
	Net unrealized gains on fixed maturities, available-for-sale (1)		$	3,021.10		$	2,067.40
	Noncredit component of impairment losses on fixed maturities, available-for-sale		(194.9		)	(277.5		)
	Net unrealized losses on equity securities, available-for-sale		(2.0		)	(3.3		)
	Adjustments for assumed changes in amortization patterns		(351.1		)	(265.9		)
	Adjustments for assumed changes in policyholder liabilities		(1,057.0		)	(621.2		)
	Net unrealized gains on derivative instruments		130			56
	Net unrealized gains on equity method subsidiaries and noncontrolling interest adjustments		84.6			87.1
	Provision for deferred income taxes		(542.3		)	(342.0		)
	Net unrealized gains on available-for-sale securities and derivative instruments		$	1,088.40		$	700.6
	(1)         Excludes net unrealized gains (losses) on fixed maturities, available-for-sale included in fair value hedging relationships.
Mortgage Loans (Table)	'
			September 30, 2014			December 31, 2013
			(in millions)
	Commercial mortgage loans		$	10,596.80		$	10,327.70
	Residential mortgage loans		1,206.10			1,275.70
	Total amortized cost		11,802.90			11,603.40
	Valuation allowance		(58.0		)	(69.8		)
	Total carrying value		$	11,744.90		$	11,533.60
Commercial Mortgage Loans by Geographic Distribution and Property Type Distribution (Table)	'
			September 30, 2014					December 31, 2013
			Amortized			Percent		Amortized			Percent
			cost			of total		cost			of total
			($ in millions)
	Geographic distribution
	New England		$	508.6		4.8	%	$	528.5		5.1	%
	Middle Atlantic		2,798.30			26.4		2,489.00			24.1
	East North Central		462.4			4.4		519.9			5
	West North Central		253			2.4		302.9			2.9
	South Atlantic		1,944.60			18.4		1,949.50			18.9
	East South Central		199.6			1.9		192.8			1.9
	West South Central		1,003.60			9.5		830.3			8
	Mountain		755.6			7.1		747.1			7.2
	Pacific		2,631.10			24.7		2,722.50			26.5
	International		40			0.4		45.2			0.4
	Total		$	10,596.80		100	%	$	10,327.70		100	%
	Property type distribution
	Office		$	3,461.50		32.7	%	$	3,360.50		32.6	%
	Retail		2,463.00			23.2		2,668.50			25.8
	Industrial		1,942.20			18.3		1,766.20			17.1
	Apartments		2,065.20			19.5		1,911.20			18.5
	Hotel		337.1			3.2		333.1			3.2
	Mixed use/other		327.8			3.1		288.2			2.8
	Total		$	10,596.80		100	%	$	10,327.70		100	%
Commercial Mortgage Loan Portfolio by Credit Risk (Table)	'
			September 30, 2014
			Brick and mortar			CTL			Total
			(in millions)
	A- and above		$	8,762.30		$	179.2		$	8,941.50
	BBB+ thru BBB-		1,211.80			195.2			1,407.00
	BB+ thru BB-		181.9			—			181.9
	B+ and below		64.7			1.7			66.4
	Total		$	10,220.70		$	376.1		$	10,596.80
			December 31, 2013
			Brick and mortar			CTL			Total
			(in millions)
	A- and above		$	8,091.90		$	194.5		$	8,286.40
	BBB+ thru BBB-		1,463.70			250			1,713.70
	BB+ thru BB-		155.4			0.1			155.5
	B+ and below		170.1			2			172.1
	Total		$	9,881.10		$	446.6		$	10,327.70
Performing and Non-Performing Residential Mortgage Loans (Table)	'
			September 30, 2014
			Home equity			First liens			Total
			(in millions)
	Performing		$	307.3		$	868.1		$	1,175.40
	Nonperforming		15.1			15.6			30.7
	Total		$	322.4		$	883.7		$	1,206.10
			December 31, 2013
			Home equity			First liens			Total
			(in millions)
	Performing		$	378.3		$	862.1		$	1,240.40
	Nonperforming		16.6			18.7			35.3
	Total		$	394.9		$	880.8		$	1,275.70
Non-Accrual Mortgage Loans (Table)	'
			September 30, 2014			December 31, 2013
			(in millions)
	Commercial:
	Brick and mortar		$	10.7		$	33.2
	Residential:
	Home equity		15.1			16.6
	First liens		9.8			11.4
	Total		$	35.6		$	61.2
Mortgage Loans Aging (Table)	'
			September 30, 2014
																			Recorded
																			investment
									90 days or										90 days or
			30-59 days			60-89 days			more past			Total past							more and
			past due			past due			due			due			Current		Total loans		accruing
			(in millions)
	Commercial-brick and mortar		$	—		$	—		$	0.9		$	0.9		$	10,219.80	$	10,220.70	$	—
	Commercial-CTL		—			—			—			—			376.1		376.1		—
	Residential-home equity		2.5			2.4			2.2			7.1			315.3		322.4		—
	Residential-first liens		23.8			4.8			14.9			43.5			840.2		883.7		5.8
	Total		$	26.3		$	7.2		$	18		$	51.5		$	11,751.40	$	11,802.90	$	5.8
			December 31, 2013
																			Recorded
																			investment
									90 days or										90 days or
			30-59 days			60-89 days			more past			Total past							more and
			past due			past due			due			due			Current		Total loans		accruing
			(in millions)
	Commercial-brick and mortar		$	—		$	—		$	16.7		$	16.7		$	9,864.40	$	9,881.10	$	—
	Commercial-CTL		—			—			—			—			446.6		446.6		—
	Residential-home equity		4.4			1			3			8.4			386.5		394.9		—
	Residential-first liens		32.4			7.4			17.1			56.9			823.9		880.8		7.3
	Total		$	36.8		$	8.4		$	36.8		$	82		$	11,521.40	$	11,603.40	$	7.3
Mortgage Loan Valuation Allowance (Table)	'
			For the three months ended September 30, 2014
			Commercial			Residential			Total
			(in millions)
	Beginning balance		$	26.4		$	38.5		$	64.9
	Provision		1.4			6.5			7.9
	Charge-offs		—			(15.1		)	(15.1		)
	Recoveries		—			0.3			0.3
	Ending balance		$	27.8		$	30.2		$	58
			For the nine months ended September 30, 2014
			Commercial			Residential			Total
			(in millions)
	Beginning balance		$	28.7		$	41.1		$	69.8
	Provision		(0.6		)	7.3			6.7
	Charge-offs		(0.3		)	(20.8		)	(21.1		)
	Recoveries		—			2.7			2.7
	Effect of exchange rates		—			(0.1		)	(0.1		)
	Ending balance		$	27.8		$	30.2		$	58
	Allowance ending balance by basis of impairment method:
	Individually evaluated for impairment		$	3.1		$	9.4		$	12.5
	Collectively evaluated for impairment		24.7			20.8			45.5
	Allowance ending balance		$	27.8		$	30.2		$	58
	Loan balance by basis of impairment method:
	Individually evaluated for impairment		$	9.8		$	29.6		$	39.4
	Collectively evaluated for impairment		10,587.00			1,176.50			11,763.50
	Loan ending balance		$	10,596.80		$	1,206.10		$	11,802.90
			For the three months ended September 30, 2013
			Commercial			Residential			Total
			(in millions)
	Beginning balance		$	47.7		$	47.2		$	94.9
	Provision		0.7			1.3			2
	Charge-offs		(6.2		)	(3.7		)	(9.9		)
	Recoveries		0.2			0.7			0.9
	Ending balance		$	42.4		$	45.5		$	87.9
			For the nine months ended September 30, 2013
			Commercial			Residential			Total
			(in millions)
	Beginning balance		$	51.8		$	45.6		$	97.4
	Provision		6.7			12.6			19.3
	Charge-offs		(16.9		)	(15.0		)	(31.9		)
	Recoveries		0.8			2.4			3.2
	Effect of exchange rates		—			(0.1		)	(0.1		)
	Ending balance		$	42.4		$	45.5		$	87.9
	Allowance ending balance by basis of impairment method:
	Individually evaluated for impairment		$	8.5		$	10.4		$	18.9
	Collectively evaluated for impairment		33.9			35.1			69
	Allowance ending balance		$	42.4		$	45.5		$	87.9
	Loan balance by basis of impairment method:
	Individually evaluated for impairment		$	30.7		$	34.7		$	65.4
	Collectively evaluated for impairment		10,627.60			1,263.00			11,890.60
	Loan ending balance		$	10,658.30		$	1,297.70		$	11,956.00
Impaired Mortgage Loans (Table)	'
			September 30, 2014
						Unpaid
			Recorded			principal			Related
			investment			balance			allowance
			(in millions)
	With no related allowance recorded:
	Commercial-brick and mortar		$	0.9		$	2.2		$	—
	Residential-first liens		4			4			—
	With an allowance recorded:
	Commercial-brick and mortar		9.8			9.8			3.1
	Residential-home equity		17.6			19.2			8.5
	Residential-first liens		8			7.9			0.9
	Total:
	Commercial		$	10.7		$	12		$	3.1
	Residential		$	29.6		$	31.1		$	9.4
			December 31, 2013
						Unpaid
			Recorded			principal			Related
			investment			balance			allowance
			(in millions)
	With no related allowance recorded:
	Commercial-brick and mortar		$	21.5		$	32.7		$	—
	Residential-first liens		4.6			4.6			—
	With an allowance recorded:
	Commercial-brick and mortar		4.4			4.4			2.4
	Residential-home equity		19.5			19.7			9.2
	Residential-first liens		8.9			7.8			1
	Total:
	Commercial		$	25.9		$	37.1		$	2.4
	Residential		$	33		$	32.1		$	10.2
			For the three months ended						For the nine months ended
			September 30, 2014						September 30, 2014
			Average						Average
			recorded			Interest income			recorded			Interest income
			investment			recognized			investment			recognized
			(in millions)
	With no related allowance recorded:
	Commercial-brick and mortar		$	0.9		$	—		$	11.2		$	0.1
	Residential-first liens		4.1			—			4.3			—
	With an allowance recorded:
	Commercial-brick and mortar		7.1			0.1			7.1			0.2
	Residential-home equity		18			0.2			18.6			0.5
	Residential-first liens		8			—			8.5			0.1
	Total:
	Commercial		$	8		$	0.1		$	18.3		$	0.3
	Residential		$	30.1		$	0.2		$	31.4		$	0.6
			For the three months ended						For the nine months ended
			September 30, 2013						September 30, 2013
			Average						Average
			recorded			Interest income			recorded			Interest income
			investment			recognized			investment			recognized
			(in millions)
	With no related allowance recorded:
	Commercial-brick and mortar		$	6.4		$	0.1		$	16.2		$	0.2
	Residential-first liens		6.2			—			7.9			—
	With an allowance recorded:
	Commercial-brick and mortar		28.4			0.1			17.5			0.2
	Residential-home equity		20.2			0.4			20.3			0.8
	Residential-first liens		9.3			—			9			0.1
	Total:
	Commercial		$	34.8		$	0.2		$	33.7		$	0.4
	Residential		$	35.7		$	0.4		$	37.2		$	0.9
Mortgage Loans Modified as a Troubled Debt Restructuring (Table)	'
			For the three months ended September 30, 2014
			TDRs					TDRs in payment default
			Number of		Recorded			Number of		Recorded
			contracts		investment			contracts		investment
					(in millions)					(in millions)
	Commercial-brick and mortar		2		$	5.4		1		$	0.7
	Residential-home equity		37		1.6			1		—
	Total		39		$	7		2		$	0.7
			For the three months ended September 30, 2013
			TDRs					TDRs in payment default
			Number of		Recorded			Number of		Recorded
			contracts		investment			contracts		investment
					(in millions)					(in millions)
	Residential-home equity		12		$	0.8		—		$	—
	Residential-first liens		—		—			1		0.1
	Total		12		$	0.8		1		$	0.1
			For the nine months ended September 30, 2014
			TDRs					TDRs in payment default
			Number of		Recorded			Number of		Recorded
			contracts		investment			contracts		investment
					(in millions)					(in millions)
	Commercial-brick and mortar		4		$	10.5		1		$	0.7
	Residential-home equity		75		2.9			3		—
	Residential-first liens		1		0.1			—		—
	Total		80		$	13.5		4		$	0.7
			For the nine months ended September 30, 2013
			TDRs					TDRs in payment default
			Number of		Recorded			Number of		Recorded
			contracts		investment			contracts		investment
					(in millions)					(in millions)
	Commercial-brick and mortar		2		$	0.9		—		$	—
	Residential-home equity		60		3.1			13		—
	Residential-first liens		3		0.6			3		0.8
	Total		65		$	4.6		16		$	0.8
Financial Assets Subject to Netting Agreements (Table)	'
						Gross amounts not offset in the
						Statement of Financial Position
			Gross amount
			of recognized			Financial			Collateral
			assets (1)			instruments (2)			received			Net amount
			(in millions)
	September 30, 2014
	Derivative assets		$	558.7		$	(451.0	)	$	(89.8	)	$	17.9
	Reverse repurchase agreements		50.8			—			(50.8		)	—
	Total		$	609.5		$	(451.0	)	$	(140.6	)	$	17.9
	December 31, 2013
	Derivative assets		$	664.9		$	(581.5	)	$	(82.1	)	$	1.3
	Reverse repurchase agreements		51.8			—			(51.8		)	—
	Total		$	716.7		$	(581.5	)	$	(133.9	)	$	1.3
	(1)     The gross amount of recognized derivative and reverse repurchase agreement assets are reported with other investments and cash and cash equivalents on the consolidated statements of financial position. The above excludes $0.0 million and $0.2 million of derivative assets as of September 30, 2014 and December 31, 2013, respectively, that are not subject to master netting agreements or similar agreements. The gross amounts of derivative and reverse repurchase agreement assets are not netted against offsetting liabilities for presentation on the consolidated statements of financial position.
	(2)     Represents amount of offsetting derivative liabilities that are subject to an enforceable master netting agreement or similar agreement that are not netted against the gross derivative assets for presentation on the consolidated statements of financial position.
Financial Liabilities Subject to Netting Agreements (Table)	'
						Statement of Financial Position
			Gross amount
			of recognized			Financial			Collateral
			liabilities (1)			instruments (2)			pledged			Net amount
			(in millions)
	September 30, 2014
	Derivative liabilities		$	789.3		$	(451.0	)	$	(239.9	)	$	98.4
	December 31, 2013
	Derivative liabilities		$	1,022.00		$	(581.5	)	$	(362.1	)	$	78.4
	(1)     The gross amount of recognized derivative liabilities are reported with other liabilities on the consolidated statements of financial position. The above excludes $341.4 million and $226.7 million of derivative liabilities as of September 30, 2014 and December 31, 2013, respectively, which are primarily embedded derivatives that are not subject to master netting agreements or similar agreements. The gross amounts of derivative liabilities are not netted against offsetting assets for presentation on the consolidated statements of financial position.
	(2)     Represents amount of offsetting derivative assets that are subject to an enforceable master netting agreement or similar agreement that are not netted against the gross derivative liabilities for presentation on the consolidated statements of financial position.

Derivative_Financial_Instrumen1

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2014
Derivative Financial Instruments	'
Derivative Financial Instruments, Exposure (Table)	'
		September 30, 2014			December 31, 2013
		(in millions)
	Notional amounts of derivative instruments
	Interest rate contracts:
	Interest rate swaps	$	18,747.50		$	20,570.80
	Interest rate options	4,900.00			4,100.00
	Swaptions	260			325
	Interest rate futures	139.5			92.5
	Foreign exchange contracts:
	Currency swaps	2,034.50			2,367.50
	Currency forwards	264			247.4
	Equity contracts:
	Equity options	2,967.80			2,010.40
	Equity futures	422.5			273.3
	Credit contracts:
	Credit default swaps	1,280.60			1,153.20
	Total return swaps	70			90
	Futures	28.1			9.1
	Other contracts:
	Embedded derivative financial instruments	9,058.60			7,601.10
	Total notional amounts at end of period	$	40,173.10		$	38,840.30
	Credit exposure of derivative instruments
	Interest rate contracts:
	Interest rate swaps	$	424.2		$	435.5
	Interest rate options	38.2			42.5
	Swaptions	0.1			1
	Foreign exchange contracts:
	Currency swaps	93.6			200.9
	Currency forwards	—			0.6
	Equity contracts:
	Equity options	20.4			30
	Credit contracts:
	Credit default swaps	12.5			9.5
	Total return swaps	0.3			0.1
	Total gross credit exposure	589.3			720.1
	Less: collateral received	108.9			115.9
	Net credit exposure	$	480.4		$	604.2
Derivative Financial Instruments, Fair Value Disclosures (Table)	'
		Derivative assets (1)						Derivative liabilities (2)
		September 30, 2014			December 31, 2013			September 30, 2014			December 31, 2013
		(in millions)
	Derivatives designated as hedging instruments
	Interest rate contracts	$	0.5		$	0.1		$	201.8		$	285.4
	Foreign exchange contracts	70.2			121.6			43.1			51.2
	Total derivatives designated as hedging instruments	$	70.7		$	121.7		$	244.9		$	336.6
	Derivatives not designated as hedging instruments
	Interest rate contracts	$	425.6		$	452.2		$	327.9		$	489.6
	Foreign exchange contracts	29.2			51.6			39.2			17.9
	Equity contracts	20.4			30			148.1			145
	Credit contracts	12.8			9.6			34.5			35.5
	Other contracts	—			—			336.1			224.1
	Total derivatives not designated as hedging instruments	488			543.4			885.8			912.1
	Total derivative instruments	$	558.7		$	665.1		$	1,130.70		$	1,248.70
	(1)     The fair value of derivative assets is reported with other investments on the consolidated statements of financial position.
	(2)     The fair value of derivative liabilities is reported with other liabilities on the consolidated statements of financial position, with the exception of certain embedded derivative liabilities. Embedded derivative liabilities with a fair value of $94.1 million and $6.9 million as of September 30, 2014 and December 31, 2013, respectively, are reported with contractholder funds on the consolidated statements of financial position.
Credit Derivatives Sold (Table)	'
		September 30, 2014
											Weighted
								Maximum			average
		Notional			Fair			future			expected life
		amount			value			payments			(in years)
		(in millions)
	Single name credit default swaps
	Corporate debt
	AAA	$	30		$	1		$	30		4.5
	AA	99			1.8			99			3.7
	A	294.5			4.4			294.5			3.5
	BBB	385			4.6			385			3.9
	BB	15			(0.4		)	15			3.7
	Total single name credit default swaps	823.5			11.4			823.5			3.7
	Basket and index credit default swaps
	Corporate debt
	Near default (1)	100.4			(22.5		)	100.4			2.5
	Government/municipalities
	AA	30			(2.3		)	30			3
	Structured finance
	BBB	25			(0.3		)	25			2.8
	Total basket and index credit default swaps	155.4			(25.1		)	155.4			2.6
	Total credit default swap protection sold	$	978.9		$	(13.7	)	$	978.9		3.5
		December 31, 2013
											Weighted
								Maximum			average
		Notional			Fair			future			expected life
		amount			value			payments			(in years)
		(in millions)
	Single name credit default swaps
	Corporate debt
	AAA	$	10		$	0.3		$	10		4.7
	AA	84			1.8			84			4
	A	294.5			4.2			294.5			4
	BBB	265			(1.2		)	265			3.9
	Total single name credit default swaps	653.5			5.1			653.5			4
	Basket and index credit default swaps
	Corporate debt
	Near default (1)	110.4			(19.9		)	110.4			3.2
	Government/municipalities
	AA	30			(3.5		)	30			3.7
	Structured finance
	BBB	25			(0.9		)	25			3.5
	Total basket and index credit default swaps	165.4			(24.3		)	165.4			3.4
	Total credit default swap protection sold	$	818.9		$	(19.2	)	$	818.9		3.9
	(1)         Includes $78.0 million and $88.0 million as of September 30, 2014 and December 31, 2013, respectively, notional of derivatives in consolidated collateralized private investment vehicle VIEs where the credit risk is borne by third-party investors.
Hybrid Instruments (Table)	'
		September 30, 2014
								Weighted
								average
		Amortized			Carrying			expected life
		cost			value			(in years)
		(in millions)
	Corporate debt
	A	$	23.8		$	23.8		2.3
	Total corporate debt	23.8			23.8			2.3
	Structured finance
	A	49.8			49.8			2.1
	BB	5.8			5.8			2.7
	CCC	9.4			9.4			4.3
	Total structured finance	65			65			2.5
	Total fixed maturities with credit derivatives	$	88.8		$	88.8		2.4
		December 31, 2013
								Weighted
								average
		Amortized			Carrying			expected life
		cost			value			(in years)
		(in millions)
	Corporate debt
	BBB	$	23.4		$	23.4		3
	Total corporate debt	23.4			23.4			3
	Structured finance
	A	18.1			16.7			4.8
	BB	5.5			5.5			3.3
	B	4.1			4.1			3.1
	CCC	23.5			23.5			4.8
	Total structured finance	51.2			49.8			4.5
	Total fixed maturities with credit derivatives	$	74.6		$	73.2		4
Fair Value Hedges (Table)	'
										Amount of gain (loss)
		Amount of gain (loss)								recognized in net income on
		recognized in net income on								related hedged item for the
		derivatives for the three months								three months ended
	Derivatives in fair value hedging	ended September 30, (1)						Hedged items in fair value		September 30, (1)
	relationships	2014			2013			hedging relationships		2014			2013
		(in millions)								(in millions)
	Interest rate contracts	$	18.5		$	14.6		Fixed maturities, available- for-sale		$	(18.3	)	$	(14.1	)
	Interest rate contracts	(2.4		)	1.2			Investment-type insurance contracts		2.4			(1.5		)
	Foreign exchange contracts	3			(1.1		)	Fixed maturities, available- for-sale		(3.1		)	1.2
	Foreign exchange contracts	—			35			Investment-type insurance contracts		—			(34.9		)
	Total	$	19.1		$	49.7		Total		$	(19.0	)	$	(49.3	)
										Amount of gain (loss)
		Amount of gain (loss)								recognized in net income on
		recognized in net income on								related hedged item for the
		derivatives for the nine months								for the nine months
	Derivatives in fair value hedging	ended September 30, (1)						Hedged items in fair value		ended September 30, (1)
	relationships	2014			2013			hedging relationships		2014			2013
		(in millions)								(in millions)
	Interest rate contracts	$	27.2		$	110.9		Fixed maturities, available- for-sale		$	(28.4	)	$	(105.4	)
	Interest rate contracts	0.2			1.2			Investment-type insurance contracts		(0.1		)	(1.5		)
	Foreign exchange contracts	3.8			0.2			Fixed maturities, available- for-sale		(3.8		)	—
	Foreign exchange contracts	0.2			(39.1		)	Investment-type insurance contracts		(0.2		)	38.7
	Total	$	31.4		$	73.2		Total		$	(32.5	)	$	(68.2	)
	(1)         The gain (loss) on both derivatives and hedged items in fair value relationships is reported in net realized capital gains (losses) on the consolidated statements of operations. The net amount represents the ineffective portion of our fair value hedges.
Fair Value Hedges, Periodic Settlements Disclosures (Table)	'
		Amount of gain (loss) for the three						Amount of gain (loss) for the
		months ended September 30,						nine months ended September 30,
	Hedged item	2014			2013			2014			2013
		(in millions)
	Fixed maturities, available-for-sale (1)	$	(22.2	)	$	(30.9	)	$	(71.5	)	$	(92.1	)
	Investment-type insurance contracts (2)	1			9.9			3.4			29.2
	(1)         Reported in net investment income on the consolidated statements of operations.
	(2)         Reported in benefits, claims and settlement expenses on the consolidated statements of operations.
Cash Flow Hedges (Table)	'
				Amount of gain (loss)								Amount of gain (loss)
				recognized in AOCI on								reclassified from AOCI on
				derivatives (effective portion)						Location of gain (loss)		derivatives (effective portion)
	Derivatives in cash			for the three months ended						reclassified from AOCI		for the three months ended
	flow hedging			September 30,						into net income		September 30,
	relationships	Related hedged item		2014			2013			(effective portion)		2014			2013
				(in millions)								(in millions)
	Interest rate contracts	Fixed maturities, available-for-sale		$	8.8		$	(10.2	)	Net investment income		$	3.5		$	3
	Interest rate contracts	Investment-type insurance contracts		0.2			0.6			Benefits, claims and settlement expenses		—			—
	Interest rate contracts	Debt		—			—			Operating expense		(1.9		)	(1.7		)
	Foreign exchange contracts	Fixed maturities, available-for-sale		44.6			(44.7		)	Net realized capital gains (losses)		0.2			(3.2		)
	Foreign exchange contracts	Investment-type insurance contracts		1.3			2.8			Benefits, claims and settlement expenses		—			—
	Total			$	54.9		$	(51.5	)	Total		$	1.8		$	(1.9	)
				Amount of gain (loss)								Amount of gain (loss)
				recognized in AOCI on								reclassified from AOCI on
				derivatives (effective portion)						Location of gain (loss)		derivatives (effective portion)
	Derivatives in cash			for the nine months ended						reclassified from AOCI		for the nine months ended
	flow hedging			September 30,						into net income		September 30,
	relationships	Related hedged item		2014			2013			(effective portion)		2014			2013
				(in millions)								(in millions)
	Interest rate contracts	Fixed maturities, available-for-sale		$	10.8		$	(51.4	)	Net investment income		$	10.1		$	8.6
	Interest rate contracts	Investment-type insurance contracts		2.6			1.7			Benefits, claims and settlement expenses		—			—
	Interest rate contracts	Debt		—			—			Operating expense		(5.5		)	(4.9		)
	Foreign exchange contracts	Fixed maturities, available-for-sale		44.4			(3.1		)	Net realized capital losses		(10.9		)	(5.3		)
	Foreign exchange contracts	Investment-type insurance contracts		9.8			2.2			Benefits, claims and settlement expenses		—			—
	Total			$	67.6		$	(50.6	)	Total		$	(6.3	)	$	(1.6	)
Cash Flow Hedges, Periodic Settlements Disclosures (Table)	'
		Amount of gain (loss) for the						Amount of gain (loss) for the
		three months ended September 30,						nine months ended September 30,
	Hedged item	2014			2013			2014			2013
		(in millions)
	Fixed maturities, available-for-sale (1)	$	1.1		$	1.9		$	3.9		$	6.2
	Investment-type insurance contracts (2)	(2.6		)	(2.7		)	(8.4		)	(8.2		)
	(1)      Reported in net investment income on the consolidated statements of operations.
	(2)      Reported in benefits, claims and settlement expenses on the consolidated statements of operations.
Derivatives Not Designated as Hedging Instruments (Table)	'
		Amount of gain (loss) recognized in						Amount of gain (loss) recognized in
		net income on derivatives for the						net income on derivatives for the
		three months ended September 30,						nine months ended September 30,
	Derivatives not designated as hedging instruments	2014			2013			2014			2013
		(in millions)
	Interest rate contracts	$	38.3		$	(20.0	)	$	134.7		$	(112.1	)
	Foreign exchange contracts	(43.7		)	14.9			(56.6		)	3.1
	Equity contracts	37.7			(49.0		)	0.1			(120.5		)
	Credit contracts	(21.7		)	10.4			(10.8		)	32.8
	Other contracts	(62.0		)	18.4			(108.5		)	117.9
	Total	$	(51.4	)	$	(25.3	)	$	(41.1	)	$	(78.8	)

Income_Taxes_Tables

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2014
Income Taxes	'
Changes in Unrecognized Tax Benefits (Table)	'
		For the nine months ended			For the year ended
		September 30, 2014			December 31, 2013
		(in millions)
	Balance at beginning of period	$	108.9		$	119.5
	Additions based on tax positions related to the current year	9.4			10.5
	Additions for tax positions of prior years	64.4			10.9
	Reductions for tax positions related to the current year	(6.3		)	(3.3		)
	Reductions for tax positions of prior years	—			(28.7		)
	Balance at end of period (1)	$	176.4		$	108.9
	(1)  Of this amount, $61.6 million, if recognized, would reduce the 2014 effective income tax rate. We recognize interest and penalties related to uncertain tax positions in operating expenses.

Employee_and_Agent_Benefits_Ta

Employee and Agent Benefits (Tables)	9 Months Ended
	Sep. 30, 2014
Employee and Agent Benefits	'
Components of Net Periodic Benefit Cost (Income) (Table)	'
								Other postretirement
		Pension benefits						benefits
		For the three months ended						For the three months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
	Service cost	$	13.5		$	14.3		$	0.4		$	0.3
	Interest cost	29.2			25.9			1.7			1.4
	Expected return on plan assets	(33.0		)	(31.8		)	(8.2		)	(7.2		)
	Amortization of prior service benefit	(1.0		)	(2.1		)	(5.0		)	(6.5		)
	Recognized net actuarial (gain) loss	12.5			29.5			(1.0		)	0.3
	Net periodic benefit cost (income)	$	21.2		$	35.8		$	(12.1	)	$	(11.7	)
								Other postretirement
		Pension benefits						benefits
		For the nine months ended						For the nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
	Service cost	$	40.5		$	42.9		$	1.1		$	0.9
	Interest cost	87.8			77.7			5			4.2
	Expected return on plan assets	(99.0		)	(95.6		)	(24.5		)	(21.6		)
	Amortization of prior service benefit	(3.4		)	(6.3		)	(15.2		)	(19.5		)
	Recognized net actuarial (gain) loss	37.8			88.6			(2.7		)	0.9
	Net periodic benefit cost (income)	$	63.7		$	107.3		$	(36.3	)	$	(35.1	)

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2014
Stockholders' Equity	'
Reconciliation of Outstanding Shares (Table)	'
		Series A		Series B		Common
		preferred stock		preferred stock		stock
		(in millions)
	Outstanding shares at January 1, 2013	3		10		293.8
	Shares issued	—		—		4.5
	Treasury stock acquired	—		—		(4.4	)
	Outstanding shares at September 30, 2013	3		10		293.9
	Outstanding shares at January 1, 2014	3		10		295.2
	Shares issued	—		—		3.1
	Treasury stock acquired	—		—		(4.7	)
	Outstanding shares at September 30, 2014	3		10		293.6
Other Comprehensive Income (Loss) (Table)	'
		For the three months ended									For the nine months ended
		September 30, 2014									September 30, 2014
		Pre-Tax			Tax			After-Tax			Pre-Tax			Tax			After-Tax
		(in millions)
	Net unrealized gains (losses) on available-for-sale securities during the period	$	(301.8	)	$	103.8		$	(198.0	)	$	1,009.90		$	(340.7	)	$	669.2
	Reclassification adjustment for (gains) losses included in net income (1)	4.3			(1.4		)	2.9			(57.4		)	18.8			(38.6		)
	Adjustments for assumed changes in amortization patterns	28.2			(9.8		)	18.4			(71.0		)	24.9			(46.1		)
	Adjustments for assumed changes in policyholder liabilities	149.8			(47.0		)	102.8			(434.7		)	146.8			(287.9		)
	Net unrealized gains (losses) on available-for-sale securities	(119.5		)	45.6			(73.9		)	446.8			(150.2		)	296.6
	Noncredit component of impairment losses on fixed maturities, available-for-sale during the period	14.7			(5.0		)	9.7			82.6			(29.3		)	53.3
	Adjustments for assumed changes in amortization patterns	3.1			(1.2		)	1.9			(5.3		)	1.9			(3.4		)
	Adjustments for assumed changes in policyholder liabilities	(0.9		)	0.3			(0.6		)	(1.5		)	0.5			(1.0		)
	Noncredit component of impairment losses on fixed maturities, available-for-sale (2)	16.9			(5.9		)	11			75.8			(26.9		)	48.9
	Net unrealized gains on derivative instruments during the period	48.4			(17.0		)	31.4			67.7			(23.8		)	43.9
	Reclassification adjustment for (gains) losses included in net income (3)	(1.8		)	0.6			(1.2		)	6.3			(2.4		)	3.9
	Adjustments for assumed changes in amortization patterns	(8.4		)	2.9			(5.5		)	(8.9		)	3.1			(5.8		)
	Adjustments for assumed changes in policyholder liabilities	6.9			(2.4		)	4.5			0.4			(0.1		)	0.3
	Net unrealized gains on derivative instruments	45.1			(15.9		)	29.2			65.5			(23.2		)	42.3
	Foreign currency translation adjustment	(210.3		)	14.5			(195.8		)	(231.2		)	22.8			(208.4		)
	Amortization of prior service cost and actuarial loss included in net periodic benefit cost (4)	5.5			(1.9		)	3.6			16.5			(5.8		)	10.7
	Net unrecognized postretirement benefit obligation	5.5			(1.9		)	3.6			16.5			(5.8		)	10.7
	Other comprehensive income (loss)	$	(262.3	)	$	36.4		$	(225.9	)	$	373.4		$	(183.3	)	$	190.1
		For the three months ended									For the nine months ended
		September 30, 2013									September 30, 2013
		Pre-Tax			Tax			After-Tax			Pre-Tax			Tax			After-Tax
		(in millions)
	Net unrealized losses on available-for-sale securities during the period	$	(40.9	)	$	9.1		$	(31.8	)	$	(1,578.4	)	$	511.6		$	(1,066.8	)
	Reclassification adjustment for losses included in net income (1)	8.4			(2.9		)	5.5			66.8			(22.7		)	44.1
	Adjustments for assumed changes in amortization patterns	29.3			(10.3		)	19			241.1			(84.4		)	156.7
	Adjustments for assumed changes in policyholder liabilities	54.1			(17.5		)	36.6			505.7			(163.4		)	342.3
	Net unrealized gains (losses) on available-for-sale securities	50.9			(21.6		)	29.3			(764.8		)	241.1			(523.7		)
	Noncredit component of impairment losses on fixed maturities, available-for-sale during the period	9.3			(2.9		)	6.4			(8.8		)	3.9			(4.9		)
	Adjustments for assumed changes in amortization patterns	(13.7		)	4.9			(8.8		)	(13.6		)	4.9			(8.7		)
	Adjustments for assumed changes in policyholder liabilities	(0.2		)	0.1			(0.1		)	0.8			(0.3		)	0.5
	Noncredit component of impairment losses on fixed maturities, available-for-sale (2)	(4.6		)	2.1			(2.5		)	(21.6		)	8.5			(13.1		)
	Net unrealized losses on derivative instruments during the period	(45.7		)	15.9			(29.8		)	(31.7		)	11.7			(20.0		)
	Reclassification adjustment for losses included in net income (3)	1.9			(0.8		)	1.1			1.6			(0.8		)	0.8
	Adjustments for assumed changes in amortization patterns	2.6			(1.0		)	1.6			9			(3.2		)	5.8
	Adjustments for assumed changes in policyholder liabilities	2.7			(0.7		)	2			15.3			(5.3		)	10
	Net unrealized losses on derivative instruments	(38.5		)	13.4			(25.1		)	(5.8		)	2.4			(3.4		)
	Foreign currency translation adjustment	(32.0		)	(1.5		)	(33.5		)	(177.3		)	7.8			(169.5		)
	Amortization of prior service cost and actuarial loss included in net periodic benefit cost (4)	21.2			(7.4		)	13.8			63.7			(22.3		)	41.4
	Net unrecognized postretirement benefit obligation	21.2			(7.4		)	13.8			63.7			(22.3		)	41.4
	Other comprehensive loss	$	(3.0	)	$	(15.0	)	$	(18.0	)	$	(905.8	)	$	237.5		$	(668.3	)
	(1)     Pre-tax reclassification adjustments relating to available-for-sale securities are reported in net realized capital gains (losses) on the consolidated statements of operations.
	(2)     Represents the net impact of (1) unrealized gains resulting from reclassification of previously recognized noncredit impairment losses from OCI to net realized capital gains (losses) for fixed maturities with bifurcated OTTI that had additional credit losses or fixed maturities that previously had bifurcated OTTI that have now been sold or are intended to be sold and (2) unrealized losses resulting from reclassification of noncredit impairment losses for fixed maturities with bifurcated OTTI from net realized capital gains (losses) to OCI.
	(3)     See Note 4, Derivative Financial Instruments — Cash Flow Hedges, for further details.
	(4)     Pre-tax amortization of prior service cost and actuarial loss included in net periodic benefit cost, which is comprised of amortization of prior service cost (benefit) and recognized net actuarial (gain) loss, is reported in operating expenses on the consolidated statements of operations. See Note 6, Employee and Agent Benefits — Components of Net Periodic Benefit Cost, for further details.
Accumulated Other Comprehensive Income (Loss) (Table)	'
					Noncredit
		Net unrealized			component of			Net unrealized			Foreign			Unrecognized			Accumulated
		gains on			impairment losses			gains (losses) on			currency			postretirement			other
		available-for-sale			on fixed maturities			derivative			translation			benefit			comprehensive
		securities			available-for-sale			instruments			adjustment			obligation			income (loss)
		(in millions)
	Balances at January 1, 2013	$	1,418.30		$	(173.9	)	$	(8.7	)	$	(106.9	)	$	(488.5	)	$	640.3
	Other comprehensive loss during the period, net of adjustments	(567.8		)	(13.1		)	(4.2		)	(159.2		)	—			(744.3		)
	Amounts reclassified from AOCI	44.1			—			0.8			—			41.4			86.3
	Other comprehensive loss	(523.7		)	(13.1		)	(3.4		)	(159.2		)	41.4			(658.0		)
	Balances at September 30, 2013	$	894.6		$	(187.0	)	$	(12.1	)	$	(266.1	)	$	(447.1	)	$	(17.7	)
	Balances at January 1, 2014	$	878.1		$	(167.0	)	$	(10.5	)	$	(361.5	)	$	(155.9	)	$	183.2
	Other comprehensive income during the period, net of adjustments	335.2			—			38.4			(201.6		)	—			172
	Amounts reclassified from AOCI	(38.6		)	48.9			3.9			—			10.7			24.9
	Other comprehensive income	296.6			48.9			42.3			(201.6		)	10.7			196.9
	Balances at September 30, 2014	$	1,174.70		$	(118.1	)	$	31.8		$	(563.1	)	$	(145.2	)	$	380.1
Redeemable Noncontrolling Interest (Table)	'
	Following is a reconciliation of the changes in the redeemable noncontrolling interest (in millions):
	Balance at January 1, 2013	$	60.4
	Net income attributable to redeemable noncontrolling interest	9
	Reclassification from stockholders’ equity (1)	173.9
	Redeemable noncontrolling interest assumed related to acquisition	1.2
	Distributions to redeemable noncontrolling interest	(9.9		)
	Purchase of subsidiary shares from redeemable noncontrolling interest	(2.4		)
	Change in redemption value of redeemable noncontrolling interest	5.6
	Foreign currency translation adjustment	(3.3		)
	Balance at September 30, 2013	$	234.5
	Balance at January 1, 2014	$	247.2
	Net income attributable to redeemable noncontrolling interest	8.3
	Contributions from redeemable noncontrolling interest	0.1
	Distributions to redeemable noncontrolling interest	(14.4		)
	Purchase of subsidiary shares from redeemable noncontrolling interest (2)	(216.8		)
	Change in redemption value of redeemable noncontrolling interest	33.2
	Foreign currency translation adjustment	(1.5		)
	Balance at September 30, 2014	$	56.1
	(1)     During the third quarter of 2013, we identified a classification error of certain of our noncontrolling interests. The classification error had no impact on net income, but did impact earnings per share to the extent the redemption value of the redeemable noncontrolling interest exceeds the fair value. We evaluated the classification error and related earnings per share impact based on qualitative and quantitative factors in accordance with SEC Staff Accounting Bulletins 99 and 108 and concluded the impact was not material in the current or any prior quarterly or annual periods presented. During the third quarter of 2013, we recorded a $173.9 million increase to redeemable noncontrolling interest and a corresponding decrease to stockholders’ equity. See related discussion in Note 12, Earnings Per Share.
	(2)     The decrease during the third quarter of 2014 was primarily due to an increased ownership stake in Columbus Circle Investors.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Measurements	'
Fair Value (Table)	'
		As of September 30, 2014
		Assets/
		(liabilities)
		measured at			Fair value hierarchy level
		fair value			Level 1			Level 2			Level 3
		(in millions)
	Assets
	Fixed maturities, available-for-sale:
	U.S. government and agencies	$	892.1		$	519		$	373.1		$	—
	Non-U.S. governments	904.7			—			863.4			41.3
	States and political subdivisions	4,094.00			—			4,092.30			1.7
	Corporate	32,020.20			40.3			31,757.70			222.2
	Residential mortgage-backed securities	2,809.00			—			2,809.00			—
	Commercial mortgage-backed securities	4,012.30			—			4,006.90			5.4
	Collateralized debt obligations	480.8			—			419.2			61.6
	Other debt obligations	4,414.40			—			4,368.70			45.7
	Total fixed maturities, available-for-sale	49,627.50			559.3			48,690.30			377.9
	Fixed maturities, trading	609.4			4.9			465.2			139.3
	Equity securities, available-for-sale	124.8			40.3			67.1			17.4
	Equity securities, trading	807.6			102.5			705.1			—
	Derivative assets (1)	558.7			—			501			57.7
	Other investments (2)	420.6			3.3			293			124.3
	Cash equivalents (3)	473.2			—			473.2			—
	Sub-total excluding separate account assets	52,621.80			710.3			51,194.90			716.6
	Separate account assets	138,296.70			71,356.30			61,163.00			5,777.40
	Total assets	$	190,918.50		$	72,066.60		$	112,357.90		$	6,494.00
	Liabilities
	Investment-type insurance contracts (4)	$	(94.1	)	$	—		$	—		$	(94.1	)
	Derivative liabilities (1)	(794.6		)	—			(756.8		)	(37.8		)
	Other liabilities (4)	(307.8		)	—			(246.8		)	(61.0		)
	Total liabilities	$	(1,196.5	)	$	—		$	(1,003.6	)	$	(192.9	)
	Net assets	$	189,722.00		$	72,066.60		$	111,354.30		$	6,301.10
		As of December 31, 2013
		Assets/
		(liabilities)
		measured at			Fair value hierarchy level
		fair value			Level 1			Level 2			Level 3
		(in millions)
	Assets
	Fixed maturities, available-for-sale:
	U.S. government and agencies	$	780.5		$	409.3		$	371.2		$	—
	Non-U.S. governments	996.8			—			949.3			47.5
	States and political subdivisions	3,658.00			—			3,656.20			1.8
	Corporate	31,919.00			40.3			31,714.70			164
	Residential mortgage-backed securities	2,845.20			—			2,845.20			—
	Commercial mortgage-backed securities	4,026.40			—			4,024.80			1.6
	Collateralized debt obligations	363.4			—			325.6			37.8
	Other debt obligations	4,167.80			—			4,083.70			84.1
	Total fixed maturities, available-for-sale	48,757.10			449.6			47,970.70			336.8
	Fixed maturities, trading	563.1			—			393.2			169.9
	Equity securities, available-for-sale	110.5			38.1			55.5			16.9
	Equity securities, trading	716.9			105.1			611.8			—
	Derivative assets (1)	665.1			—			590.9			74.2
	Other investments (2)	361.1			6.8			211.4			142.9
	Cash equivalents (3)	1,459.00			—			1,459.00			—
	Sub-total excluding separate account assets	52,632.80			599.6			51,292.50			740.7
	Separate account assets	130,018.40			67,215.10			57,538.10			5,265.20
	Total assets	$	182,651.20		$	67,814.70		$	108,830.60		$	6,005.90
	Liabilities
	Investment-type insurance contracts (4)	$	(6.9	)	$	—		$	—		$	(6.9	)
	Derivative liabilities (1)	(1,024.6		)	—			(985.0		)	(39.6		)
	Other liabilities (4)	(322.1		)	—			(248.2		)	(73.9		)
	Total liabilities	$	(1,353.6	)	$	—		$	(1,233.2	)	$	(120.4	)
Net assets	$	181,297.60		$	67,814.70		$	107,597.40		$	5,885.50
(1)     Within the consolidated statements of financial position, derivative assets are reported with other investments and derivative liabilities are reported with other liabilities. Refer to Note 4, Derivative Financial Instruments, for further information on fair value by class of derivative instruments. Our derivatives are primarily Level 2, with the exception of certain credit default swaps and other swaps that are Level 3.
(2)     Primarily includes seed money investments, other investment funds, commercial mortgage loans of consolidated VIEs and equity method investments reported at fair value.
(3)     Includes money market instruments and short-term investments with a maturity date of three months or less when purchased.
(4)     Includes bifurcated embedded derivatives that are reported at fair value within the same line item in the consolidated statements of financial position in which the host contract is reported. Other liabilities also include obligations of consolidated VIEs reported at fair value.
Reconciliation for All Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Table)	'
		For the three months ended September 30, 2014																					Changes in
		Beginning									Net									Ending			unrealized
		asset/			Total realized/unrealized						purchases,									asset/			gains (losses)
		(liability)			gains (losses)						sales,									(liability)			included in
		balance						Included in			issuances									balance			net income
		as of			Included in			other			and			Transfers			Transfers			as of			relating to
		June 30,			net income			comprehensive			settlements			into			out of			September 30,			positions still
		2014			-1			income			-4			Level 3			Level 3			2014			held (1)
		(in millions)
	Assets
	Fixed maturities, available-for-sale:
	Non-U.S. governments	$	39.6		$	—		$	(0.2	)	$	1.9		$	—		$	—		$	41.3		$	—
	States and political subdivisions	1.7			—			—			—			—			—			1.7			—
	Corporate	170			(1.4		)	(2.8		)	40.7			15.7			—			222.2			(1.4		)
	Commercial mortgage-backed securities	6.7			(1.0		)	0.2			0.2			0.7			(1.4		)	5.4			(0.9		)
	Collateralized debt obligations	68.5			—			0.1			9.5			—			(16.5		)	61.6			—
	Other debt obligations	47.1			—			—			(1.4		)	—			—			45.7			—
	Total fixed maturities, available-for-sale	333.6			(2.4		)	(2.7		)	50.9			16.4			(17.9		)	377.9			(2.3		)
	Fixed maturities, trading	159.6			3.7			—			(24.0		)	—			—			139.3			0.2
	Equity securities, available-for-sale	17.5			(0.3		)	0.2			—			—			—			17.4			(0.3		)
	Derivative assets	62.3			(14.4		)	—			9.8			—			—			57.7			(14.3		)
	Other investments	134.6			3.8			—			(14.1		)	—			—			124.3			3.8
	Separate account assets (2)	5,533.60			167			(0.3		)	79			2.3			(4.2		)	5,777.40			163.7
	Liabilities
	Investment-type insurance contracts	(37.6		)	(62.8		)	—			6.3			—			—			(94.1		)	(56.1		)
	Derivative liabilities	(24.7		)	(13.3		)	(0.6		)	0.8			—			—			(37.8		)	(14.5		)
	Other liabilities (3)	(79.9		)	9.9			—			9			—			—			(61.0		)	9.8
		For the three months ended September 30, 2013																					Changes in
		Beginning									Net									Ending			unrealized
		asset/			Total realized/unrealized						purchases,									asset/			gains (losses)
		(liability)			gains (losses)						sales,									(liability)			included in
		balance			Included in			Included in			issuances									balance			net income
		as of			net			other			and			Transfers			Transfers			as of			relating to
		June 30,			income			comprehensive			settlements			into			out of			September 30,			positions still
		2013			-1			income			-4			Level 3			Level 3			2013			held (1)
		(in millions)
	Assets
	Fixed maturities, available-for-sale:
	Non-U.S. governments	$	44.7		$	—		$	(0.3	)	$	3.4		$	—		$	—		$	47.8		$	—
	States and political subdivisions	1.7			—			0.1			—			—			—			1.8			—
	Corporate	168.1			(0.1		)	2.7			17.1			4.7			(29.5		)	163			(0.1		)
	Collateralized debt obligations	40.7			—			(0.1		)	—			—			(2.6		)	38			—
	Other debt obligations	18.4			(0.3		)	0.6			13.6			15			—			47.3			(0.3		)
	Total fixed maturities, available-for-sale	273.6			(0.4		)	3			34.1			19.7			(32.1		)	297.9			(0.4		)
	Fixed maturities, trading	170.7			2.1			—			0.1			—			—			172.9			2.1
	Equity securities, available-for-sale	16.9			—			0.3			—			—			—			17.2			—
	Derivative assets	56.9			1			—			(0.4		)	—			—			57.5			1.2
	Other investments	116.5			1.8			—			22.2			—			—			140.5			1.9
	Separate account assets (2)	4,841.70			134.6			0.1			(33.7		)	4.9			(6.3		)	4,941.30			122
	Liabilities
	Investment-type insurance contracts	(74.2		)	17.6			—			7.3			—			—			(49.3		)	19.8
	Derivative liabilities	(70.0		)	14.1			0.3			5.6			—			—			(50.0		)	14.2
	Other liabilities (3)	(59.6		)	(7.5		)	—			—			—			—			(67.1		)	(7.6		)
		For the nine months ended September 30, 2014																					Changes in
		Beginning									Net									Ending			unrealized
		asset/			Total realized/unrealized						purchases,									asset/			gains (losses)
		(liability)			gains (losses)						sales,									(liability)			included in
		balance			Included			Included in			issuances									balance			net income
		as of			in net			other			and			Transfers			Transfers			as of			relating to
		December 31,			income			comprehensive			settlements			into			out of			September 30,			positions still
		2013			-1			income			-4			Level 3			Level 3			2014			held (1)
		(in millions)
	Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	47.5		$	(0.1	)	$	(0.2	)	$	(5.9	)	$	—		$	—		$	41.3		$	(0.1	)
States and political subdivisions	1.8			—			—			(0.1		)	—			—			1.7			—
Corporate	164			(1.6		)	(1.7		)	21			46.6			(6.1		)	222.2			(1.5		)
Commercial mortgage-backed securities	1.6			(1.6		)	1.3			(0.2		)	6.8			(2.5		)	5.4			(1.5		)
Collateralized debt obligations	37.8			—			1.4			46.4			—			(24.0		)	61.6			—
Other debt obligations	84.1			—			1.1			(9.8		)	—			(29.7		)	45.7			—
Total fixed maturities, available-for-sale	336.8			(3.3		)	1.9			51.4			53.4			(62.3		)	377.9			(3.1		)
Fixed maturities, trading	169.9			9.5			—			(40.1		)	—			—			139.3			0.8
Equity securities, available-for-sale	16.9			(0.3		)	0.6			—			0.2			—			17.4			(0.3		)
Derivative assets	74.2			(26.4		)	—			9.9			—			—			57.7			(26.4		)
Other investments	142.9			6.6			—			(25.2		)	—			—			124.3			6.6
Separate account assets (2)	5,265.20			358.4			(0.2		)	161.3			4.4			(11.7		)	5,777.40			359.9
Liabilities
Investment-type insurance contracts	(6.9		)	(109.9		)	—			22.7			—			—			(94.1		)	(109.9		)
Derivative liabilities	(39.6		)	0.5			0.7			0.6			—			—			(37.8		)	(3.7		)
Other liabilities (3)	(73.9		)	3.9			—			9			—			—			(61.0		)	4.5
	For the nine months ended September 30, 2013																					Changes in
	Beginning									Net									Ending			unrealized
	asset/			Total realized/unrealized						purchases,									asset/			gains (losses)
	(liability)			gains (losses)						sales,									(liability)			included in
	balance			Included			Included in			issuances									balance			net income
	as of			in net			other			and			Transfers			Transfers			as of			relating to
	December 31,			income			comprehensive			settlements			into			out of			September 30,			positions still
	2012			-1			income			-4			Level 3			Level 3			2013			held (1)
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	44.3		$	(0.1	)	$	(0.8	)	$	4.4		$	—		$	—		$	47.8		$	(0.1	)
States and political subdivisions	1.9			—			—			(0.1		)	—			—			1.8			—
Corporate	174.5			(4.9		)	(7.0		)	(25.3		)	105.3			(79.6		)	163			(2.0		)
Collateralized debt obligations	77.6			2.1			7.4			(56.0		)	31.7			(24.8		)	38			—
Other debt obligations	14.7			(0.3		)	3			12.7			17.2			—			47.3			(0.3		)
Total fixed maturities, available-for-sale	313			(3.2		)	2.6			(64.3		)	154.2			(104.4		)	297.9			(2.4		)
Fixed maturities, trading	166.8			6			—			0.1			—			—			172.9			6.1
Equity securities, available-for-sale	15.3			—			1.9			—			—			—			17.2			—
Derivative assets	75.1			(21.3		)	—			3.7			—			—			57.5			(21.6		)
Other investments	113.9			7.1			—			19.5			—			—			140.5			7.1
Separate account assets (2)	4,616.00			427.2			—			(108.1		)	12.7			(6.5		)	4,941.30			406.3
Liabilities
Investment-type insurance contracts	(170.5		)	111.2			—			10			—			—			(49.3		)	109.2
Derivative liabilities	(102.6		)	44.4			(0.2		)	8.4			—			—			(50.0		)	43.8
Other liabilities (3)	(39.6		)	(27.5		)	—			—			—			—			(67.1		)	(27.5		)
(1)       Both realized gains (losses) and mark-to-market unrealized gains (losses) are generally reported in net realized capital gains (losses) within the consolidated statements of operations. Realized and unrealized gains (losses) on certain fixed maturities, trading and certain derivatives used in relation to certain trading portfolios are reported in net investment income within the consolidated statements of operation.
(2)       Gains and losses for separate account assets do not impact net income as the change in value of separate account assets is offset by a change in value of separate account liabilities. Foreign currency translation adjustments related to the Principal International segment separate account assets are recorded in AOCI and are offset by foreign currency translation adjustments of the corresponding separate account liabilities.
(3)       Certain embedded derivatives reported in other liabilities are part of a cash flow hedge, with the effective portion of the unrealized gains (losses) recorded in AOCI.
(4)       Gross purchases, sales, issuances and settlements were:
	For the three months ended September 30, 2014
													Net purchases,
													sales, issuances
	Purchases			Sales			Issuances			Settlements			and settlements
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	2.2		$	—		$	—		$	(0.3	)	$	1.9
Corporate	46.5			(5.5		)	—			(0.3		)	40.7
Commercial mortgage-backed securities	—			—			—			0.2			0.2
Collateralized debt obligations	9.7			—			—			(0.2		)	9.5
Other debt obligations	—			—			—			(1.4		)	(1.4		)
Total fixed maturities, available-for-sale	58.4			(5.5		)	—			(2.0		)	50.9
Fixed maturities, trading	—			(10.0		)	—			(14.0		)	(24.0		)
Derivative assets	9.8			—			—			—			9.8
Other investments	—			—			—			(14.1		)	(14.1		)
Separate account assets (5)	228.5			(127.3		)	(196.5		)	174.3			79
Liabilities
Investment-type insurance contracts	—			—			4.2			2.1			6.3
Derivative liabilities	(0.6		)	1.4			—			—			0.8
Other liabilities	—			9			—			—			9
	For the three months ended September 30, 2013
													Net purchases,
													sales, issuances
	Purchases			Sales			Issuances			Settlements			and settlements
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	3.7		$	—		$	—		$	(0.3	)	$	3.4
Corporate	18.2			(0.7		)	—			(0.4		)	17.1
Other debt obligations	15			—			—			(1.4		)	13.6
Total fixed maturities, available-for-sale	36.9			(0.7		)	—			(2.1		)	34.1
Fixed maturities, trading	—			—			—			0.1			0.1
Derivative assets	—			(0.4		)	—			—			(0.4		)
Other investments	25.7			—			—			(3.5		)	22.2
Separate account assets (5)	33.6			(54.7		)	(1.4		)	(11.2		)	(33.7		)
Liabilities
Investment-type insurance contracts	—			—			5.4			1.9			7.3
Derivative liabilities	—			5.6			—			—			5.6
	For the nine months ended September 30, 2014
													Net purchases,
													sales, issuances
	Purchases			Sales			Issuances			Settlements			and settlements
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. government	$	5.8		$	(10.8	)	$	—		$	(0.9	)	$	(5.9	)
States and political subdivisions	—			—			—			(0.1		)	(0.1		)
Corporate	64.5			(39.2		)	—			(4.3		)	21
Commercial mortgage-backed securities	—			—			—			(0.2		)	(0.2		)
Collateralized debt obligations	61.3			—			—			(14.9		)	46.4
Other debt obligations	—			—			—			(9.8		)	(9.8		)
Total fixed maturities, available-for-sale	131.6			(50.0		)	—			(30.2		)	51.4
Fixed maturities, trading	—			(10.0		)	—			(30.1		)	(40.1		)
Derivative assets	9.9			—			—			—			9.9
Other investments	0.2			—			—			(25.4		)	(25.2		)
Separate account assets (5)	467.2			(257.5		)	(290.1		)	241.7			161.3
Liabilities
Investment-type insurance contracts	—			—			18.7			4			22.7
Derivative liabilities	(0.8		)	1.4			—			—			0.6
Other liabilities	—			9			—			—			9
	For the nine months ended September 30, 2013
													Net purchases,
													sales, issuances
	Purchases			Sales			Issuances			Settlements			and settlements
	(in millions)
Assets
Fixed maturities, available-for-sale:
Non-U.S. government	$	9.2		$	(3.9	)	$	—		$	(0.9	)	$	4.4
State and political subdivisions	—			—			—			(0.1		)	(0.1		)
Corporate	29.6			(32.4		)	—			(22.5		)	(25.3		)
Collateralized debt obligations	17			(47.4		)	—			(25.6		)	(56.0		)
Other debt obligations	15			—			—			(2.3		)	12.7
Total fixed maturities, available-for-sale	70.8			(83.7		)	—			(51.4		)	(64.3		)
Fixed maturities, trading	—			—			—			0.1			0.1
Derivative assets	7.2			(3.5		)	—			—			3.7
Other investments	28.3			—			—			(8.8		)	19.5
Separate account assets (5)	143.2			(223.4		)	(7.6		)	(20.3		)	(108.1		)
Liabilities
Investment-type insurance contracts	—			—			5.6			4.4			10
Derivative liabilities	(3.1		)	11.5			—			—			8.4
(5)         Issuances and settlements include amounts related to mortgage encumbrances associated with real estate in our separate accounts.
Transfers (Table)	'
		For the three months ended September 30, 2014
		Transfers out			Transfers out			Transfers out			Transfers out			Transfers out			Transfers out
		of Level 1 into			of Level 1 into			of Level 2 into			of Level 2 into			of Level 3 into			of Level 3 into
		Level 2			Level 3			Level 1			Level 3			Level 1			Level 2
		(in millions)
	Assets
	Fixed maturities, available-for- sale:
	Corporate	$	—		$	—		$	—		$	15.7		$	—		$	—
	Commercial mortgage-backed securities	—			—			—			0.7			—			1.4
	Collateralized debt obligations	—			—			—			—			—			16.5
	Total fixed maturities, available-for-sale	—			—			—			16.4			—			17.9
	Separate account assets	2.1			—			17.5			2.3			—			4.2
		For the three months ended September 30, 2013
		Transfers out			Transfers out			Transfers out			Transfers out			Transfers out			Transfers out
		of Level 1 into			of Level 1 into			of Level 2 into			of Level 2 into			of Level 3 into			of Level 3 into
		Level 2			Level 3			Level 1			Level 3			Level 1			Level 2
		(in millions)
	Assets
	Fixed maturities, available-for- sale:
	Corporate	$	—		$	—		$	—		$	4.7		$	—		$	29.5
	Collateralized debt obligations	—			—			—			—			—			2.6
	Other debt obligations	—			—			—			15			—			—
	Total fixed maturities, available-for-sale	—			—			—			19.7			—			32.1
	Separate account assets	7.1			—			6.9			4.9			—			6.3
		For the nine months ended September 30, 2014
		Transfers out			Transfers out			Transfers out			Transfers out			Transfers out			Transfers out
		of Level 1 into			of Level 1 into			of Level 2 into			of Level 2 into			of Level 3 into			of Level 3 into
		Level 2			Level 3			Level 1			Level 3			Level 1			Level 2
		(in millions)
	Assets
	Fixed maturities, available-for- sale:
	Corporate	$	—		$	—		$	—		$	46.6		$	—		$	6.1
	Commercial mortgage-backed securities	—			—			—			6.8			—			2.5
	Collateralized debt obligations	—			—			—			—			—			24
	Other debt obligations	—			—			—			—			—			29.7
	Total fixed maturities, available-for-sale	—			—			—			53.4			—			62.3
	Equity securities, available-for- sale	—			—			—			0.2			—			—
	Separate account assets	17.5			—			71.3			4.4			—			11.7
		For the nine months ended September 30, 2013
		Transfers out			Transfers out			Transfers out			Transfers out			Transfers out			Transfers out
		of Level 1 into			of Level 1 into			of Level 2 into			of Level 2 into			of Level 3 into			of Level 3 into
		Level 2			Level 3			Level 1			Level 3			Level 1			Level 2
		(in millions)
	Assets
	Fixed maturities, available-for- sale:
	Corporate	$	—		$	—		$	—		$	105.3		$	—		$	79.6
	Collateralized debt obligations	—			—			—			31.7			—			24.8
	Other debt obligations	—			—			—			17.2			—			—
	Total fixed maturities, available-for-sale	—			—			—			154.2			—			104.4
	Separate account assets	250.9			0.1			11.7			12.6			—			6.5
Quantitative Information about Level 3 Fair Value Measurements (Table)	'
		As of September 30, 2014
		Assets /
		(liabilities)
		measured at			Valuation		Unobservable		Input/range of		Weighted
		fair value			technique(s)		input description		inputs		average
		(in millions)
	Assets
	Fixed maturities, available-for-sale:
	Non-U.S. governments	$	10.7		Discounted cash flow		Discount rate (1)		2.00%		2.00%
							Illiquidity premium		50 basis points (“bps”)		50bps
	Corporate	71.7			Discounted cash flow		Discount rate (1)		1.8%-7.5%		4.20%
							Comparability adjustment		0bps-4bps		0bps
							Illiquidity premium		0bps-50bps		16bps
	Commercial mortgage-backed securities	5			Discounted cash flow		Discount rate (1)		4.0%-17.6%		17.60%
	Collateralized debt obligations	9.7			Discounted cash flow		Discount rate (1)		2.60%		2.60%
	Other debt obligations	31.2			Discounted cash flow		Discount rate (1)		1.4%-5.0%		2.30%
							Illiquidity premium		50bps-1,000bps		283bps
	Fixed maturities, trading	15.1			Discounted cash flow		Discount rate (1)		1.7%-124.1%		3.30%
							Illiquidity premium		200bps-1,400bps		450bps
		100.4			See note (2)
		As of September 30, 2014
		Assets /
		(liabilities)
		measured at		Valuation		Unobservable		Input/range of		Weighted
		fair value		technique(s)		input description		inputs		average
		(in millions)
	Other investments	41.9		Discounted cash flow - commercial mortgage loans of consolidated VIEs		Discount rate (1)		4.20%		4.20%
						Illiquidity premium		70bps		70bps
		82.4		Discounted cash flow - equity method real estate investments		Discount rate (1)		7.5%-8.1%		7.80%
						Terminal capitalization rate		5.5%-6.8%		6.10%
						Average market rent growth rate		3.4%-3.9%		3.60%
				Discounted cash flow - equity method real estate investment - debt		Loan to value		37.9%-60.3%		49.10%
						Credit spread rate		1.8%-2.0%		1.90%
	Separate account assets	5,605.60		Discounted cash flow - mortgage loans		Discount rate (1)		1.0%-6.1%		3.10%
						Illiquidity premium		0bps-60bps		7bps
						Credit spread rate		62bps-556bps		203bps
				Discounted cash flow - real estate		Discount rate (1)		6.0%-22.8%		7.50%
						Terminal capitalization rate		4.5%-9.5%		6.40%
						Average market rent growth rate		1.4%-5.0%		3.10%
				Discounted cash flow - real estate debt		Loan to value		8.5%-65.3%		47.80%
						Credit spread rate		1.1%-4.7%		2.40%
		As of September 30, 2014
		Assets /
		(liabilities)
		measured at		Valuation		Unobservable		Input/range of		Weighted
		fair value		technique(s)		input description		inputs		average
		(in millions)
	Liabilities
	Investment-type insurance contracts	(94.1	)	Discounted cash flow		Long duration interest rate		3.1%-3.2% (3)
						Long-term equity market volatility		14.9%-38.4%
						Non-performance risk		0.1%-1.2%
						Utilization rate		See note (4)
						Lapse rate		0.5%-14.6%
						Mortality rate		See note (5)
	Derivative liabilities	(11.9	)	See note (2)
	Other liabilities	(61.0	)	See note (2)
		As of December 31, 2013
		Assets /
		(liabilities)
		measured at			Valuation		Unobservable		Input/range of		Weighted
		fair value			technique(s)		input description		inputs		average
		(in millions)
	Assets
Fixed maturities, available-for-sale:
Non-U.S. governments	$	11.7		Discounted cash flow		Discount rate (1)		2.00%		2.00%
						Illiquidity premium		50 bps		50bps
Corporate	70.1			Discounted cash flow		Discount rate (1)		1.9%-7.7%		4.40%
						Illiquidity premium		0bps-25bps		15bps
						Earnings before interest, taxes, depreciation and amortization multiple		0x-4.5x		0.2x
						Comparability adjustment		0bps - 125bps		43bps
						Probability of default		0%-100%		5.40%
						Potential loss severity		0%-16%		0.90%
Commercial mortgage-backed securities	1.6			Discounted cash flow		Discount rate (1)		1.5%-4.5%		1.50%
Collateralized debt obligations	13.6			Discounted cash flow		Discount rate (1)		1.50%		1.50%
						Illiquidity premium		400bps		400bps
	As of December 31, 2013
	Assets /
	(liabilities)
	measured at		Valuation		Unobservable		Input/range of		Weighted
	fair value		technique(s)		input description		inputs		average
	(in millions)
Other debt obligations	33.6		Discounted cash flow		Discount rate (1)		2.0%-15.0%		6.70%
					Illiquidity premium		0bps-50bps		11bps
Fixed maturities, trading	36.2		Discounted cash flow		Discount rate (1)		1.6%-83.0%		3.40%
					Illiquidity premium		0bps-1,400bps		370bps
	110.4		See note (2)
Other investments	68.1		Discounted cash flow - commercial mortgage loans of consolidated VIEs		Discount rate (1)		4.80%		4.80%
					Illiquidity premium		94bps		94bps
	74.8		Discounted cash flow - equity method real estate investment		Discount rate (1)		7.8%-8.1%		7.90%
					Terminal capitalization rate		5.5%-6.8%		6.10%
					Average market rent growth rate		3.5%-3.6%		3.60%
			Discounted cash flow - equity method real estate investment debt		Loan to value		40.5%-61.0%		50.70%
					Credit spread rate		1.5%-2.0%		1.80%
	As of December 31, 2013
	Assets /
	(liabilities)
	measured at		Valuation		Unobservable		Input/range of		Weighted
	fair value		technique(s)		input description		inputs		average
	(in millions)
Separate account assets	5,090.40		Discounted cash flow - mortgage loans		Discount rate (1)		0.6%-5.6%		3.30%
					Illiquidity premium		0bps-60bps		12bps
					Credit spread rate		32bps-440bps		214bps
			Discounted cash flow - real estate		Discount rate (1)		6.0%-16.0%		7.60%
					Terminal capitalization rate		4.5%-9.0%		6.60%
					Average market rent growth rate		2.4%-4.7%		3.00%
			Discounted cash flow - real estate debt		Loan to value		11.0%-55.9%		50.30%
					Credit spread rate		1.5%-5.2%		3.30%
Liabilities
Investment-type insurance contracts	(6.9	)	Discounted cash flow		Long duration interest rate		3.8%-3.9% (3)
					Long-term equity market volatility		15.0%-40.1%
					Non-performance risk		0.2%-1.2%
					Utilization rate		See note (4)
					Lapse rate		0.5%-14.6%
					Mortality rate		See note (5)
Derivative liabilities	(19.9	)	See note (2)
Other liabilities	(73.9	)	See note (2)
(1)     Represents market comparable interest rate or an index adjusted rate used as the base rate in the discounted cash flow analysis prior to any credit spread, illiquidity or other adjustments, where applicable.
(2)     Relates to a consolidated collateralized private investment vehicle that is a VIE. Fixed maturities, trading represents the underlying collateral of the investment structure and consists of high-grade fixed maturity investments, which are over-collateralized based on outstanding notes priced at par. The derivative liability represents credit default swaps that are valued using a correlation model to the credit default swap (“CDS”) Index (“CDX”) and inputs to the valuation are based on observable market data such as the end of period swap curve, CDS constituents of the index and spread levels of the index, as well as CDX tranche spreads. The other liabilities represent obligations to third party note holders due at maturity or termination of the trust. The value of the obligations reflect the third parties’ interest in the investment structure.
(3)     Represents the range of rate curves used in the valuation analysis that we have determined market participants would use when pricing the instrument. Derived from interpolation between observable 20 and 30-year swap rates.
(4)     This input factor is the number of contractholders taking withdrawals as well as the amount and timing of the withdrawals and a range does not provide a meaningful presentation.
(5)     This input is based on an appropriate industry mortality table and a range does not provide a meaningful presentation.
Financial Instruments Not Reported at Fair Value (Table)	'
		September 30, 2014
								Fair value hierarchy level
		Carrying amount			Fair value			Level 1			Level 2			Level 3
		(in millions)
	Assets (liabilities)
	Mortgage loans	$	11,744.90		$	12,233.70		$	—		$	—		$	12,233.70
	Policy loans	837.7			1,031.80			—			—			1,031.80
	Other investments	195			195.5			—			164.6			30.9
	Cash and cash equivalents	797.6			797.6			797.6			—			—
	Investments-type insurance contracts	(28,371.8		)	(28,494.4		)	—			(5,282.5		)	(23,211.9		)
	Short-term debt	(126.3		)	(126.3		)	—			(126.3		)	—
	Long-term debt	(2,529.2		)	(2,756.7		)	—			(2,676.3		)	(80.3		)
	Separate account liabilities	(127,104.9		)	(125,755.0		)	—			—			(125,755.0		)
	Bank deposits	(1,946.7		)	(1,953.1		)	(1,294.1		)	(659.0		)	—
	Cash collateral payable	(79.6		)	(79.6		)	(79.6		)	—			—
		December 31, 2013
								Fair value hierarchy level
		Carrying amount			Fair value			Level 1			Level 2			Level 3
		(in millions)
	Assets (liabilities)
	Mortgage loans	$	11,533.60		$	11,773.50		$	—		$	—		$	11,773.50
	Policy loans	859.7			963.3			—			—			963.3
	Other investments	174			174.7			—			140.9			33.8
	Cash and cash equivalents	912.8			912.8			912.8			—			—
	Investments-type insurance contracts	(29,909.6		)	(30,093.1		)	—			(5,902.2		)	(24,190.9		)
	Short-term debt	(150.6		)	(150.6		)	—			(150.6		)	—
	Long-term debt	(2,601.4		)	(2,692.1		)	—			(2,639.0		)	(53.1		)
	Separate account liabilities	(119,500.7		)	(118,059.7		)	—			—			(118,059.7		)
	Bank deposits	(1,949.0		)	(1,951.1		)	(1,252.2		)	(698.9		)	—
	Cash collateral payable	(32.5		)	(32.5		)	(32.5		)	—			—

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Information	'
Reconciliation of Assets from Segment to Consolidated (Table)	'
		September 30, 2014			December 31, 2013
		(in millions)
	Assets:
	Retirement and Investor Services	$	133,306.20		$	128,736.70
	Principal Global Investors	1,200.10			1,312.10
	Principal International	56,974.60			54,243.60
	U.S. Insurance Solutions	21,215.00			20,033.60
	Corporate	3,726.90			3,865.40
	Total consolidated assets	$	216,422.80		$	208,191.40
Reconciliation of Operating Revenues and Operating Earnings (Losses) by Segment (Table)	'
		For the three months ended						For the nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
	Operating revenues by segment:
	Retirement and Investor Services	$	1,324.70		$	1,136.50		$	3,851.00		$	3,387.60
	Principal Global Investors	173.6			160.9			517.9			482.8
	Principal International	294.5			303.3			952.2			825.9
	U.S. Insurance Solutions	821			767.6			2,436.80			2,318.60
	Corporate	(61.1		)	(52.5		)	(163.3		)	(149.1		)
	Total segment operating revenues	2,552.70			2,315.80			7,594.60			6,865.80
	Net realized capital losses, net of related revenue adjustments	(68.2		)	(76.7		)	(25.0		)	(253.4		)
	Exited group medical insurance business	(0.2		)	0.5			—			4.5
	Total revenues per consolidated statements of operations	$	2,484.30		$	2,239.60		$	7,569.60		$	6,616.90
	Operating earnings (loss) by segment, net of related income taxes:
	Retirement and Investor Services	$	204.3		$	172.9		$	632.9		$	515.2
	Principal Global Investors	25.3			23.1			79.6			72.4
	Principal International	73.8			50.7			205.1			153.6
	U.S. Insurance Solutions	83.3			54			175.7			136.9
	Corporate	(33.0		)	(31.5		)	(99.4		)	(104.2		)
	Total segment operating earnings, net of related income taxes	353.7			269.2			993.9			773.9
	Net realized capital losses, as adjusted (1)	(55.2		)	(22.8		)	(47.3		)	(126.8		)
	Other after-tax adjustments (2)	(57.8		)	(0.7		)	(105.9		)	(0.8		)
	Net income available to common stockholders per consolidated statements of operations	$	240.7		$	245.7		$	840.7		$	646.3
	(1)         Net realized capital gains (losses), as adjusted, is derived as follows:
		For the three months ended						For the nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
	Net realized capital gains (losses):
	Net realized capital gains (losses)	$	(46.4	)	$	(50.9	)	$	41		$	(181.9	)
	Certain derivative and hedging-related adjustments	(21.9		)	(25.6		)	(66.4		)	(70.7		)
	Recognition of front-end fee (revenue) expense	0.1			(0.2		)	0.4			(0.8		)
	Net realized capital losses, net of related revenue adjustments	(68.2		)	(76.7		)	(25.0		)	(253.4		)
	Amortization of deferred acquisition costs and other actuarial balances	(3.6		)	26.7			(26.8		)	44.8
	Capital gains distributed	(8.8		)	(0.2		)	(18.1		)	(11.1		)
	Certain market value adjustments of embedded derivatives	5.7			18.7			6			18.4
	Noncontrolling interest capital gains	(0.1		)	(0.2		)	(0.2		)	(0.2		)
	Income tax effect	19.8			8.9			16.8			74.7
	Net realized capital losses, as adjusted	$	(55.2	)	$	(22.8	)	$	(47.3	)	$	(126.8	)
	(2)         For the three months ended September 30, 2014, other after-tax adjustments included the negative effect of an increase in net deferred tax liabilities resulting from third quarter 2014 enactment of tax legislation in Chile ($58.1 million) and the positive effect of gains associated with our exited group medical insurance business that does not qualify for discontinued operations accounting treatment under U.S. GAAP ($0.3 million).
	For the three months ended September 30, 2013, other after-tax adjustments included the negative effect of losses associated with our exited group medical insurance business that does not qualify for discontinued operations accounting treatment under U.S. GAAP.
	For the nine months ended September 30, 2014, other after-tax adjustments included the negative effect of: (a) an increase in net deferred tax liabilities resulting from third quarter 2014 enactment of tax legislation in Chile ($58.1 million); (b) the impact of a court ruling on some uncertain tax positions ($47.5 million) and (c) losses associated with our exited group medical insurance business that does not qualify for discontinued operations accounting treatment under U.S. GAAP ($0.3 million).
	For the nine months ended September 30, 2013, other after-tax adjustments included the negative effect of losses associated with our exited group medical insurance business that does not qualify for discontinued operations accounting treatment under U.S. GAAP.
Operating Revenue for Products and Services by Segment (Table)	'
		For the three months ended						For the nine months ended
		September 30,						September 30,
		2014			2013			2014			2013
		(in millions)
	Retirement and Investor Services:
	Full service accumulation	$	392.1		$	369.9		$	1,170.00		$	1,087.70
	Principal Funds	219.7			194.8			638.2			565.9
	Individual annuities	335.6			334.5			1,082.90			881.8
	Bank and trust services	21.9			24.4			63.7			74.9
	Eliminations	(38.8		)	(38.3		)	(116.3		)	(109.1		)
	Total Accumulation	930.5			885.3			2,838.50			2,501.20
	Investment only	73.4			83.1			234.5			260.6
	Full service payout	320.8			168.1			778			625.8
	Total Guaranteed	394.2			251.2			1,012.50			886.4
	Total Retirement and Investor Services	1,324.70			1,136.50			3,851.00			3,387.60
	Principal Global Investors (1)	173.6			160.9			517.9			482.8
	Principal International	294.5			303.3			952.2			825.9
	U.S. Insurance Solutions:
	Individual life insurance	382.7			362.7			1,148.50			1,110.20
	Specialty benefits insurance	438.3			405			1,288.40			1,208.60
	Eliminations	—			(0.1		)	(0.1		)	(0.2		)
	Total U.S. Insurance Solutions	821			767.6			2,436.80			2,318.60
	Corporate	(61.1		)	(52.5		)	(163.3		)	(149.1		)
	Total operating revenues	$	2,552.70		$	2,315.80		$	7,594.60		$	6,865.80
	Total operating revenues	$	2,552.70		$	2,315.80		$	7,594.60		$	6,865.80
	Net realized capital losses (except periodic settlements and accruals on non-hedge derivatives), including recognition of front-end fee revenues and certain market value adjustments to fee revenues	(68.2		)	(76.7		)	(25.0		)	(253.4		)
	Exited group medical insurance business	(0.2		)	0.5			—			4.5
	Total revenues per consolidated statements of operations	$	2,484.30		$	2,239.60		$	7,569.60		$	6,616.90
	(1)         Reflects inter-segment revenues of $71.0 million and $61.1 million for the three months ended September 30, 2014 and 2013, respectively, and $214.4 million and $179.9 million for the nine months ended September 30, 2014 and 2013, respectively.

StockBased_Compensation_Plans_

Stock-Based Compensation Plans (Tables)	9 Months Ended
	Sep. 30, 2014
Stock-Based Compensation Plans	'
Stock-Based Compensation Disclosures (Table)	'
		For the nine months ended September 30,
		2014		2013
		(in millions)
	Compensation cost	$	50.3	$	48.5
	Related income tax benefit	16.4		14.6
	Capitalized as part of an asset	1.9		1.9

Earnings_Per_Common_Share_Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Common Share	'
Earnings Per Common Share (Table)	'
		For the three months ended				For the nine months ended
		September 30,				September 30,
		2014		2013		2014		2013
		(in millions, except per share data)
	Net income	$	252.8	$	259.1	$	896.1	$	685.7
	Subtract:
	Net income attributable to noncontrolling interest	3.9		5.2		30.7		14.7
	Preferred stock dividends	8.2		8.2		24.7		24.7
	Adjustments to redemption amounts of redeemable noncontrolling interests (1)	10.3		—		19.7		—
	Total	$	230.4	$	245.7	$	821	$	646.3
	Weighted-average shares outstanding:
	Basic	294.2		294.9		294.9		294.4
	Dilutive effects:
	Stock options	1.8		1.7		1.7		1.4
	Restricted stock units	1.8		1.7		1.7		1.6
	Performance share awards	0.4		0.3		0.4		0.3
	Diluted	298.2		298.6		298.7		297.7
	Net income per common share:
	Basic	$	0.78	$	0.83	$	2.78	$	2.2
	Diluted	$	0.77	$	0.82	$	2.75	$	2.17
	(1)         During the third quarter of 2013, we identified a classification error of certain of our noncontrolling interests, which had a related impact to earnings per share. See related discussion in Note 8, Stockholders’ Equity — Noncontrolling Interest. The correction of the classification error in the third quarter of 2013 did not significantly impact earnings per share.

Condensed_Consolidating_Financ1

Condensed Consolidating Financial Information (Tables)	9 Months Ended
	Sep. 30, 2014
Condensed Consolidating Financial Information	'
Condensed Consolidating Financial Information, Notes Guarantor (Table)	'
	Condensed Consolidating Statements of Financial Position
	September 30, 2014
		Principal			Principal Life			Principal Financial						Principal
		Financial			Insurance			Services, Inc. and						Financial
		Group, Inc.			Company			Other Subsidiaries						Group, Inc.
		Parent Only			Only			Combined			Eliminations			Consolidated
		(in millions)
	Assets
	Fixed maturities, available-for-sale	$	—		$	43,630.40		$	6,394.60		$	(397.5	)	$	49,627.50
	Fixed maturities, trading	—			308.7			300.7			—			609.4
	Equity securities, available-for-sale	—			109.4			15.4			—			124.8
	Equity securities, trading	—			0.3			807.3			—			807.6
	Mortgage loans	—			10,842.00			1,245.00			(342.1		)	11,744.90
	Real estate	—			6.9			1,345.20			—			1,352.10
	Policy loans	—			808.4			29.3			—			837.7
	Investment in unconsolidated entities	12,583.20			3,180.20			5,539.40			(20,429.4		)	873.4
	Other investments	9.5			2,723.90			1,396.20			(2,012.1		)	2,117.50
	Cash and cash equivalents	150.7			149.1			833.5			137.5			1,270.80
	Accrued investment income	—			488			58.3			(1.2		)	545.1
	Premiums due and other receivables	—			1,222.90			2,022.70			(2,056.3		)	1,189.30
	Deferred acquisition costs	—			2,739.30			246.1			—			2,985.40
	Property and equipment	—			504.2			85.9			—			590.1
	Goodwill	—			54.3			980.1			—			1,034.40
	Other intangibles	—			26			1,335.40			—			1,361.40
	Separate account assets	—			89,167.70			49,129.00			—			138,296.70
	Other assets	62.4			963.2			2,591.50			(2,562.4		)	1,054.70
	Total assets	$	12,805.80		$	156,924.90		$	74,355.60		$	(27,663.5	)	$	216,422.80
	Liabilities
	Contractholder funds	$	—		$	33,458.00		$	1,527.50		$	(304.7	)	$	34,680.80
	Future policy benefits and claims	—			19,164.80			4,634.90			(400.2		)	23,399.50
	Other policyholder funds	—			747.7			64.9			(0.7		)	811.9
	Short-term debt	—			—			126.3			—			126.3
	Long-term debt	2,448.90			—			409.3			(329.0		)	2,529.20
	Income taxes currently payable	—			—			124.3			(106.2		)	18.1
	Deferred income taxes	—			337			1,055.40			(241.8		)	1,150.60
	Separate account liabilities	—			89,167.70			49,129.00			—			138,296.70
	Other liabilities	40.5			5,725.40			4,587.50			(5,368.8		)	4,984.60
	Total liabilities	2,489.40			148,600.60			61,659.10			(6,751.4		)	205,997.70
	Redeemable noncontrolling interest	—			—			56.1			—			56.1
	Stockholders’ equity
	Series A preferred stock	—			—			—			—			—
	Series B preferred stock	0.1			—			—			—			0.1
	Common stock	4.6			2.5			—			(2.5		)	4.6
	Additional paid-in capital	9,916.90			5,511.30			9,191.90			(14,703.2		)	9,916.90
	Retained earnings	5,945.20			1,978.50			2,983.40			(4,961.9		)	5,945.20
	Accumulated other comprehensive income	380.1			832			407.9			(1,239.9		)	380.1
	Treasury stock, at cost	(5,930.5		)	—			—			—			(5,930.5		)
	Total stockholders’ equity attributable to PFG	10,316.40			8,324.30			12,583.20			(20,907.5		)	10,316.40
	Noncontrolling interest	—			—			57.2			(4.6		)	52.6
	Total stockholders’ equity	10,316.40			8,324.30			12,640.40			(20,912.1		)	10,369.00
	Total liabilities and stockholders’ equity	$	12,805.80		$	156,924.90		$	74,355.60		$	(27,663.5	)	$	216,422.80
	Condensed Consolidating Statements of Financial Position
	December 31, 2013
		Principal			Principal Life			Principal Financial						Principal
		Financial			Insurance			Services, Inc. and						Financial
		Group, Inc.			Company			Other Subsidiaries						Group, Inc.
		Parent Only			Only			Combined			Eliminations			Consolidated
		(in millions)
	Assets
	Fixed maturities, available-for-sale	$	—		$	42,794.70		$	6,357.50		$	(395.1	)	$	48,757.10
	Fixed maturities, trading	—			245.5			317.6			—			563.1
	Equity securities, available-for-sale	—			102.6			7.9			—			110.5
	Equity securities, trading	—			0.3			716.6			—			716.9
Mortgage loans	—			10,501.50			1,345.90			(313.8		)	11,533.60
Real estate	—			7.9			1,263.70			—			1,271.60
Policy loans	—			830.1			29.6			—			859.7
Investment in unconsolidated entities	11,956.20			3,396.80			4,891.60			(19,364.6		)	880
Other investments	9.3			1,892.40			1,238.80			(1,076.1		)	2,064.40
Cash and cash equivalents	131.5			1,332.20			894.5			13.6			2,371.80
Accrued investment income	—			474.5			59			(1.4		)	532.1
Premiums due and other receivables	—			1,029.00			1,814.50			(1,602.5		)	1,241.00
Deferred acquisition costs	—			2,848.80			228.2			—			3,077.00
Property and equipment	—			422.1			78.6			—			500.7
Goodwill	—			54.3			1,046.00			—			1,100.30
Other intangibles	—			26.9			1,432.10			—			1,459.00
Separate account assets	—			83,790.20			46,228.20			—			130,018.40
Other assets	59.2			976.9			2,115.30			(2,017.2		)	1,134.20
Total assets	$	12,156.20		$	150,726.70		$	70,065.60		$	(24,757.1	)	$	208,191.40
Liabilities
Contractholder funds	$	—		$	34,918.00		$	1,330.70		$	(290.4	)	$	35,958.30
Future policy benefits and claims	—			18,292.90			4,625.00			(291.7		)	22,626.20
Other policyholder funds	—			705.1			54.2			(0.4		)	758.9
Short-term debt	—			—			150.6			—			150.6
Long-term debt	2,448.80			99.4			367			(313.8		)	2,601.40
Income taxes currently payable	—			—			67.4			(62.2		)	5.2
Deferred income taxes	—			(25.0		)	1,030.10			(181.1		)	824
Separate account liabilities	—			83,790.20			46,228.20			—			130,018.40
Other liabilities	23.2			5,204.80			3,911.80			(3,915.6		)	5,224.20
Total liabilities	2,472.00			142,985.40			57,765.00			(5,055.2		)	198,167.20
Redeemable noncontrolling interest	—			—			247.2			—			247.2
Stockholders’ equity
Series A preferred stock	—			—			—			—			—
Series B preferred stock	0.1			—			—			—			0.1
Common stock	4.6			2.5			—			(2.5		)	4.6
Additional paid-in capital	9,798.90			5,505.00			9,163.70			(14,668.7		)	9,798.90
Retained earnings	5,405.40			1,738.10			2,578.20			(4,316.3		)	5,405.40
Accumulated other comprehensive income	183.2			495.7			214.3			(710.0		)	183.2
Treasury stock, at cost	(5,708.0		)	—			—			—			(5,708.0		)
Total stockholders’ equity attributable to PFG	9,684.20			7,741.30			11,956.20			(19,697.5		)	9,684.20
Noncontrolling interest	—			—			97.2			(4.4		)	92.8
Total stockholders’ equity	9,684.20			7,741.30			12,053.40			(19,701.9		)	9,777.00
Total liabilities and stockholders’ equity	$	12,156.20		$	150,726.70		$	70,065.60		$	(24,757.1	)	$	208,191.40
Condensed Consolidating Statements of Operations
For the nine months ended September 30, 2014
	Principal			Principal Life			Principal Financial						Principal
	Financial			Insurance			Services, Inc. and						Financial
	Group, Inc.			Company			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Revenues
Premiums and other considerations	$	—		$	2,200.50		$	314.3		$	—		$	2,514.80
Fees and other revenues	—			1,407.50			1,451.50			(289.3		)	2,569.70
Net investment income	0.4			1,719.40			1,260.10			(535.8		)	2,444.10
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	—			674.1			(569.1		)	—			105
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	—			27.7			(9.2		)	—			18.5
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	—			(84.5		)	2			—			(82.5		)
Net impairment losses on available-for-sale securities	—			(56.8		)	(7.2		)	—			(64.0		)
Net realized capital gains (losses)	—			617.3			(576.3		)	—			41
Total revenues	0.4			5,944.70			2,449.60			(825.1		)	7,569.60
Expenses
Benefits, claims and settlement expenses	—			3,083.80			534.5			(8.6		)	3,609.70
Dividends to policyholders	—			134.5			—			—			134.5
Operating expenses	106.8			1,624.30			1,156.40			(239.8		)	2,647.70
Total expenses	106.8			4,842.60			1,690.90			(248.4		)	6,391.90
Income (loss) before income taxes	(106.4		)	1,102.10			758.7			(576.7		)	1,177.70
Income taxes (benefits)	(42.7		)	260.6			65.3			(1.6		)	281.6
Equity in the net income (loss) of subsidiaries	929.1			(125.0		)	266.4			(1,070.5		)	—
Net income	865.4			716.5			959.8			(1,645.6		)	896.1
Net income attributable to noncontrolling interest	—			—			30.7			—			30.7
Net income attributable to PFG	865.4			716.5			929.1			(1,645.6		)	865.4
Preferred stock dividends	24.7			—			—			—			24.7
Net income available to common stockholders	$	840.7		$	716.5		$	929.1		$	(1,645.6	)	$	840.7
Net income	$	865.4		$	716.5		$	959.8		$	(1,645.6	)	$	896.1
Other comprehensive income	129.6			334.8			275.7			(550.0		)	190.1
Comprehensive income	$	995		$	1,051.30		$	1,235.50		$	(2,195.6	)	$	1,086.20
Condensed Consolidating Statements of Operations
For the nine months ended September 30, 2013
	Principal			Principal Life			Principal Financial						Principal
	Financial			Insurance			Services, Inc. and						Financial
	Group, Inc.			Company			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Revenues
Premiums and other considerations	$	—		$	1,853.60		$	281.3		$	—		$	2,134.90
Fees and other revenues	—			1,272.30			1,325.80			(257.7		)	2,340.40
Net investment income	0.4			1,775.70			526.5			20.9			2,323.50
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	6.3			(630.7		)	514.8			0.1			(109.5		)
Net other-than-temporary impairment losses on available-for-sale securities	—			(75.4		)	(5.8		)	—			(81.2		)
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	—			11.4			(2.6		)	—			8.8
Net impairment losses on available-for-sale securities	—			(64.0		)	(8.4		)	—			(72.4		)
Net realized capital gains (losses)	6.3			(694.7		)	506.4			0.1			(181.9		)
Total revenues	6.7			4,206.90			2,640.00			(236.7		)	6,616.90
Expenses
Benefits, claims and settlement expenses	—			2,828.80			466.7			(9.1		)	3,286.40
Dividends to policyholders	—			144.3			—			—			144.3
Operating expenses	105.2			1,378.60			1,113.20			(224.9		)	2,372.10
Total expenses	105.2			4,351.70			1,579.90			(234.0		)	5,802.80
Income (loss) before income taxes	(98.5		)	(144.8		)	1,060.10			(2.7		)	814.1
Income taxes (benefits)	(39.4		)	(136.0		)	304			(0.2		)	128.4
Equity in the net income (loss) of subsidiaries	730.1			530.2			(11.2		)	(1,249.1		)	—
Net income	671			521.4			744.9			(1,251.6		)	685.7
Net income attributable to noncontrolling interest	—			—			14.8			(0.1		)	14.7
Net income attributable to PFG	671			521.4			730.1			(1,251.5		)	671
Preferred stock dividends	24.7			—			—			—			24.7
Net income available to common stockholders	$	646.3		$	521.4		$	730.1		$	(1,251.5	)	$	646.3
Net income	$	671		$	521.4		$	744.9		$	(1,251.6	)	$	685.7
Other comprehensive loss	(683.9		)	(438.6		)	(225.6		)	679.8			(668.3		)
Comprehensive income (loss)	$	(12.9	)	$	82.8		$	519.3		$	(571.8	)	$	17.4
Condensed Consolidating Statements of Cash Flows
For the nine months ended September 30, 2014
	Principal			Principal Life			Principal Financial						Principal
	Financial			Insurance			Services, Inc. and						Financial
	Group, Inc.			Company			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Operating activities
Net cash provided by (used in) operating activities	$	(42.3	)	$	1,729.90		$	504.6		$	5.4		$	2,197.60
Investing activities
Available-for-sale securities:
Purchases	—			(5,902.2		)	(705.1		)	11.3			(6,596.0		)
Sales	—			1,559.70			311.8			—			1,871.50
Maturities	—			4,149.40			349.9			—			4,499.30
Mortgage loans acquired or originated	—			(1,620.6		)	(118.1		)	124.5			(1,614.2		)
Mortgage loans sold or repaid	—			1,291.50			137.6			(109.3		)	1,319.80
Real estate acquired	—			(0.6		)	(246.2		)	—			(246.8		)
Net purchases of property and equipment	—			(90.3		)	(27.2		)	—			(117.5		)
Dividends and returns of capital received from unconsolidated entities	517.5			263.5			467.5			(1,248.5		)	—
Net change in other investments	(2.0		)	(83.6		)	34.9			107.3			56.6
Net cash provided by (used in) investing activities	515.5			(433.2		)	205.1			(1,114.7		)	(827.3		)
Financing activities
Issuance of common stock	69.6			(0.2		)	0.2			—			69.6
Acquisition of treasury stock	(222.5		)	—			—			—			(222.5		)
Proceeds from financing element derivatives	—			14.9			—			—			14.9
Payments for financing element derivatives	—			(41.5		)	—			—			(41.5		)
Excess tax benefits from share-based payment arrangements	0.3			3.7			4.6			—			8.6
Purchase of subsidiary shares from noncontrolling interest	—			—			(222.7		)	0.3			(222.4		)
Sale of subsidiary shares to noncontrolling interest	—			—			0.3			(0.3		)	—
Dividends to common stockholders	(276.7		)	—			—			—			(276.7		)
Dividends to preferred stockholders	(24.7		)	—			—			—			(24.7		)
Issuance of long-term debt	—			—			138.9			(102.4		)	36.5
Principal repayments of long-term debt	—			(100.0		)	(87.4		)	87.1			(100.3		)
Net repayments of short-term borrowings	—			—			(20.5		)	—			(20.5		)
Dividends and capital paid to parent	—			(467.5		)	(781.0		)	1,248.50			—
Investment contract deposits	—			3,978.20			206.1			—			4,184.30
Investment contract withdrawals	—			(5,857.3		)	(7.0		)	—			(5,864.3		)
Net decrease in banking operation deposits	—			—			(2.3		)	—			(2.3		)
Other	—			(10.1		)	0.1			—			(10.0		)
Net cash used in financing activities	(454.0		)	(2,479.8		)	(770.7		)	1,233.20			(2,471.3		)
Net increase (decrease) in cash and cash equivalents	19.2			(1,183.1		)	(61.0		)	123.9			(1,101.0		)
Cash and cash equivalents at beginning of period	131.5			1,332.20			894.5			13.6			2,371.80
Cash and cash equivalents at end of period	$	150.7		$	149.1		$	833.5		$	137.5		$	1,270.80
Condensed Consolidating Statements of Cash Flows
For the nine months ended September 30, 2013
	Principal			Principal Life			Principal Financial						Principal
	Financial			Insurance			Services, Inc. and						Financial
	Group, Inc.			Company			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Operating activities
Net cash provided by (used in) operating activities	$	(12.8	)	$	1,412.50		$	(132.2	)	$	130.4		$	1,397.90
Investing activities
Available-for-sale securities:
Purchases	—			(6,094.0		)	(926.7		)	8.4			(7,012.3		)
Sales	—			1,281.40			370.1			(24.8		)	1,626.70
Maturities	—			5,186.50			596.7			—			5,783.20
Mortgage loans acquired or originated	—			(2,226.3		)	(175.6		)	381.9			(2,020.0		)
Mortgage loans sold or repaid	—			1,408.30			583.2			(420.7		)	1,570.80
Real estate acquired	—			—			(59.0		)	—			(59.0		)
Net purchases of property and equipment	—			(20.2		)	(2.5		)	—			(22.7		)
Purchases of interests in subsidiaries, net of cash acquired	—			—			(1,268.3		)	—			(1,268.3		)
Dividends and returns of capital received from unconsolidated entities	169.3			157.9			169.3			(496.5		)	—
Net change in other investments	(3.2		)	76.1			(128.4		)	24.3			(31.2		)
Net cash provided by (used in) investing activities	166.1			(230.3		)	(841.2		)	(527.4		)	(1,432.8		)
Financing activities
Issuance of common stock	80.2			—			—			—			80.2
Acquisition of treasury stock	(153.4		)	—			—			—			(153.4		)
Proceeds from financing element derivatives	—			46.7			—			—			46.7
Payments for financing element derivatives	—			(36.9		)	—			—			(36.9		)
Excess tax benefits from share-based payment arrangements	—			2.5			6.1			—			8.6
Purchase of subsidiary shares from noncontrolling interest	—			—			(51.4		)	—			(51.4		)
Sale of subsidiary shares to noncontrolling interest	—			—			31.8			—			31.8
Dividends to common stockholders	(211.7		)	—			—			—			(211.7		)
Dividends to preferred stockholders	(24.7		)	—			—			—			(24.7		)
Issuance of long-term debt	—			—			24.1			—			24.1
Principal repayments of long-term debt	—			—			(197.8		)	(14.4		)	(212.2		)
Net proceeds from short-term borrowings	—			—			131.6			—			131.6
Dividends and capital paid to parent	—			(169.3		)	(327.2		)	496.5			—
Investment contract deposits	—			4,985.40			284.8			—			5,270.20
Investment contract withdrawals	—			(7,051.1		)	(4.5		)	—			(7,055.6		)
Net decrease in banking operation deposits	—			—			(276.2		)	—			(276.2		)
Other	—			(6.3		)	—			—			(6.3		)
Net cash used in financing activities	(309.6		)	(2,229.0		)	(378.7		)	482.1			(2,435.2		)
Net decrease in cash and cash equivalents	(156.3		)	(1,046.8		)	(1,352.1		)	85.1			(2,470.1		)
Cash and cash equivalents at beginning of period	207.1			1,698.40			2,286.90			(15.2		)	4,177.20
Cash and cash equivalents at end of period	$	50.8		$	651.6		$	934.8		$	69.9		$	1,707.10
Condensed Consolidating Financial Information, Shelf Registration Guarantor (Table)	'
	Condensed Consolidating Statements of Financial Position
	September 30, 2014
								Principal Life
		Principal			Principal			Insurance Company						Principal
		Financial			Financial			and Other						Financial
		Group, Inc.			Services, Inc.			Subsidiaries						Group, Inc.
		Parent Only			Only			Combined			Eliminations			Consolidated
		(in millions)
	Assets
	Fixed maturities, available-for-sale	$	—		$	—		$	49,627.50		$	—		$	49,627.50
	Fixed maturities, trading	—			—			609.4			—			609.4
	Equity securities, available-for-sale	—			—			124.8			—			124.8
	Equity securities, trading	—			—			807.6			—			807.6
	Mortgage loans	—			—			11,744.90			—			11,744.90
	Real estate	—			—			1,352.10			—			1,352.10
	Policy loans	—			—			837.7			—			837.7
	Investment in unconsolidated entities	12,583.20			12,103.70			841.4			(24,654.9		)	873.4
	Other investments	9.5			179			1,929.00			—			2,117.50
	Cash and cash equivalents	150.7			413			1,196.40			(489.3		)	1,270.80
	Accrued investment income	—			—			545.1			—			545.1
	Premiums due and other receivables	—			0.6			1,188.30			0.4			1,189.30
	Deferred acquisition costs	—			—			2,985.40			—			2,985.40
	Property and equipment	—			—			590.1			—			590.1
	Goodwill	—			—			1,034.40			—			1,034.40
	Other intangibles	—			—			1,361.40			—			1,361.40
	Separate account assets	—			—			138,296.70			—			138,296.70
	Other assets	62.4			152.9			1,136.60			(297.2		)	1,054.70
	Total assets	$	12,805.80		$	12,849.20		$	216,208.80		$	(25,441.0	)	$	216,422.80
	Liabilities
	Contractholder funds	$	—		$	—		$	34,680.80		$	—		$	34,680.80
	Future policy benefits and claims	—			—			23,399.50			—			23,399.50
	Other policyholder funds	—			—			811.9			—			811.9
	Short-term debt	—			—			325.4			(199.1		)	126.3
	Long-term debt	2,448.90			—			80.3			—			2,529.20
	Income taxes currently payable	—			16			83.9			(81.8		)	18.1
	Deferred income taxes	—			—			1,361.60			(211.0		)	1,150.60
	Separate account liabilities	—			—			138,296.70			—			138,296.70
	Other liabilities	40.5			250			4,956.30			(262.2		)	4,984.60
	Total liabilities	2,489.40			266			203,996.40			(754.1		)	205,997.70
	Redeemable noncontrolling interest	—			—			56.1			—			56.1
	Stockholders’ equity
	Series A preferred stock	—			—			—			—			—
	Series B preferred stock	0.1			—			—			—			0.1
	Common stock	4.6			—			17.8			(17.8		)	4.6
	Additional paid-in capital	9,916.90			9,191.90			9,284.20			(18,476.1		)	9,916.90
	Retained earnings	5,945.20			2,983.40			2,450.20			(5,433.6		)	5,945.20
	Accumulated other comprehensive income	380.1			407.9			353.5			(761.4		)	380.1
	Treasury stock, at cost	(5,930.5		)	—			(2.0		)	2			(5,930.5		)
	Total stockholders’ equity attributable to PFG	10,316.40			12,583.20			12,103.70			(24,686.9		)	10,316.40
	Noncontrolling interest	—			—			52.6			—			52.6
	Total stockholders’ equity	10,316.40			12,583.20			12,156.30			(24,686.9		)	10,369.00
	Total liabilities and stockholders’ equity	$	12,805.80		$	12,849.20		$	216,208.80		$	(25,441.0	)	$	216,422.80
	Condensed Consolidating Statements of Financial Position
	December 31, 2013
								Principal Life
		Principal			Principal			Insurance Company						Principal
		Financial			Financial			and Other						Financial
		Group, Inc.			Services, Inc.			Subsidiaries						Group, Inc.
		Parent Only			Only			Combined			Eliminations			Consolidated
		(in millions)
	Assets
	Fixed maturities, available-for-sale	$	—		$	—		$	48,757.10		$	—		$	48,757.10
	Fixed maturities, trading	—			—			563.1			—			563.1
Equity securities, available-for-sale	—			—			110.5			—			110.5
Equity securities, trading	—			—			716.9			—			716.9
Mortgage loans	—			—			11,533.60			—			11,533.60
Real estate	—			—			1,271.60			—			1,271.60
Policy loans	—			—			859.7			—			859.7
Investment in unconsolidated entities	11,956.20			11,647.60			879.8			(23,603.6		)	880
Other investments	9.3			72.7			1,982.50			(0.1		)	2,064.40
Cash and cash equivalents	131.5			688.7			2,384.00			(832.4		)	2,371.80
Accrued investment income	—			—			532.1			—			532.1
Premiums due and other receivables	—			0.1			2,330.40			(1,089.5		)	1,241.00
Deferred acquisition costs	—			—			3,077.00			—			3,077.00
Property and equipment	—			—			500.7			—			500.7
Goodwill	—			—			1,100.30			—			1,100.30
Other intangibles	—			—			1,459.00			—			1,459.00
Separate account assets	—			—			130,018.40			—			130,018.40
Other assets	59.2			94.8			1,181.00			(200.8		)	1,134.20
Total assets	$	12,156.20		$	12,503.90		$	209,257.70		$	(25,726.4	)	$	208,191.40
Liabilities
Contractholder funds	$	—		$	—		$	35,958.30		$	—		$	35,958.30
Future policy benefits and claims	—			—			22,626.20			—			22,626.20
Other policyholder funds	—			—			758.9			—			758.9
Short-term debt	—			—			443			(292.4		)	150.6
Long-term debt	2,448.80			—			1,236.90			(1,084.3		)	2,601.40
Income taxes currently payable	—			2.8			44.7			(42.3		)	5.2
Deferred income taxes	—			—			979.6			(155.6		)	824
Separate account liabilities	—			—			130,018.40			—			130,018.40
Other liabilities	23.2			544.9			5,204.10			(548.0		)	5,224.20
Total liabilities	2,472.00			547.7			197,270.10			(2,122.6		)	198,167.20
Redeemable noncontrolling interest	—			—			247.2			—			247.2
Stockholders’ equity
Series A preferred stock	—			—			—			—			—
Series B preferred stock	0.1			—			—			—			0.1
Common stock	4.6			—			17.8			(17.8		)	4.6
Additional paid-in capital	9,798.90			9,163.70			9,057.10			(18,220.8		)	9,798.90
Retained earnings	5,405.40			2,578.20			2,387.20			(4,965.4		)	5,405.40
Accumulated other comprehensive income	183.2			214.3			187.5			(401.8		)	183.2
Treasury stock, at cost	(5,708.0		)	—			(2.0		)	2			(5,708.0		)
Total stockholders’ equity attributable to PFG	9,684.20			11,956.20			11,647.60			(23,603.8		)	9,684.20
Noncontrolling interest	—			—			92.8			—			92.8
Total stockholders’ equity	9,684.20			11,956.20			11,740.40			(23,603.8		)	9,777.00
Total liabilities and stockholders’ equity	$	12,156.20		$	12,503.90		$	209,257.70		$	(25,726.4	)	$	208,191.40
Condensed Consolidating Statements of Operations
For the nine months ended September 30, 2014
							Principal Life
	Principal			Principal			Insurance						Principal
	Financial			Financial			Company and						Financial
	Group, Inc.			Services, Inc.			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Revenues
Premiums and other considerations	$	—		$	—		$	2,514.80		$	—		$	2,514.80
Fees and other revenues	—			0.3			2,569.40			—			2,569.70
Net investment income	0.4			0.5			2,443.20			—			2,444.10
Net realized capital gains, excluding impairment losses on available-for-sale securities	—			—			105			—			105
Net other-than-temporary impairment recoveries on available-for-sale securities	—			—			18.5			—			18.5
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified from other comprehensive income	—			—			(82.5		)	—			(82.5		)
Net impairment losses on available-for-sale securities	—			—			(64.0		)	—			(64.0		)
Net realized capital gains	—			—			41			—			41
Total revenues	0.4			0.8			7,568.40			—			7,569.60
Expenses
Benefits, claims and settlement expenses	—			—			3,609.70			—			3,609.70
Dividends to policyholders	—			—			134.5			—			134.5
Operating expenses	106.8			3.1			2,537.80			—			2,647.70
Total expenses	106.8			3.1			6,282.00			—			6,391.90
Income (loss) before income taxes	(106.4		)	(2.3		)	1,286.40			—			1,177.70
Income taxes (benefits)	(42.7		)	(3.2		)	327.5			—			281.6
Equity in the net income of subsidiaries	929.1			928.2			—			(1,857.3		)	—
Net income	865.4			929.1			958.9			(1,857.3		)	896.1
Net income attributable to noncontrolling interest	—			—			30.7			—			30.7
Net income attributable to PFG	865.4			929.1			928.2			(1,857.3		)	865.4
Preferred stock dividends	24.7			—			—			—			24.7
Net income available to common stockholders	$	840.7		$	929.1		$	928.2		$	(1,857.3	)	$	840.7
Net income	$	865.4		$	929.1		$	958.9		$	(1,857.3	)	$	896.1
Other comprehensive income	129.6			183.5			163.9			(286.9		)	190.1
Comprehensive income	$	995		$	1,112.60		$	1,122.80		$	(2,144.2	)	$	1,086.20
Condensed Consolidating Statements of Operations
For the nine months ended September 30, 2013
							Principal Life
	Principal			Principal			Insurance						Principal
	Financial			Financial			Company and						Financial
	Group, Inc.			Services, Inc.			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Revenues
Premiums and other considerations	$	—		$	—		$	2,134.90		$	—		$	2,134.90
Fees and other revenues	—			0.9			2,357.80			(18.3		)	2,340.40
Net investment income	0.4			1.1			2,321.80			0.2			2,323.50
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	6.3			2.6			(118.4		)	—			(109.5		)
Net other-than-temporary impairment losses on available-for-sale securities	—			—			(81.2		)	—			(81.2		)
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to other comprehensive income	—			—			8.8			—			8.8
Net impairment losses on available-for-sale securities	—			—			(72.4		)	—			(72.4		)
Net realized capital gains (losses)	6.3			2.6			(190.8		)	—			(181.9		)
Total revenues	6.7			4.6			6,623.70			(18.1		)	6,616.90
Expenses
Benefits, claims and settlement expenses	—			—			3,286.40			—			3,286.40
Dividends to policyholders	—			—			144.3			—			144.3
Operating expenses	105.2			8.4			2,276.60			(18.1		)	2,372.10
Total expenses	105.2			8.4			5,707.30			(18.1		)	5,802.80
Income (loss) before income taxes	(98.5		)	(3.8		)	916.4			—			814.1
Income taxes (benefits)	(39.4		)	(2.2		)	170			—			128.4
Equity in the net income of subsidiaries	730.1			731.7			—			(1,461.8		)	—
Net income	671			730.1			746.4			(1,461.8		)	685.7
Net income attributable to noncontrolling interest	—			—			14.7			—			14.7
Net income attributable to PFG	671			730.1			731.7			(1,461.8		)	671
Preferred stock dividends	24.7			—			—			—			24.7
Net income available to common stockholders	$	646.3		$	730.1		$	731.7		$	(1,461.8	)	$	646.3
Net income	$	671		$	730.1		$	746.4		$	(1,461.8	)	$	685.7
Other comprehensive loss	(683.9		)	(671.8		)	(679.2		)	1,366.60			(668.3		)
Comprehensive income (loss)	$	(12.9	)	$	58.3		$	67.2		$	(95.2	)	$	17.4
Condensed Consolidating Statements of Cash Flows
For the nine months ended September 30, 2014
							Principal Life
	Principal			Principal			Insurance						Principal
	Financial			Financial			Company and						Financial
	Group, Inc.			Services, Inc.			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Operating activities
Net cash provided by (used in) operating activities	$	(42.3	)	$	(373.5	)	$	2,335.40		$	278		$	2,197.60
Investing activities
Available-for-sale securities:
Purchases	—			—			(6,596.0		)	—			(6,596.0		)
Sales	—			—			1,871.50			—			1,871.50
Maturities	—			—			4,499.30			—			4,499.30
Mortgage loans acquired or originated	—			—			(1,614.2		)	—			(1,614.2		)
Mortgage loans sold or repaid	—			—			1,319.80			—			1,319.80
Real estate acquired	—			—			(246.8		)	—			(246.8		)
Net purchases of property and equipment	—			—			(117.5		)	—			(117.5		)
Dividends and returns of capital received from unconsolidated entities	517.5			714			—			(1,231.5		)	—
Net change in other investments	(2.0		)	(98.7		)	185.2			(27.9		)	56.6
Net cash provided by (used in) investing activities	515.5			615.3			(698.7		)	(1,259.4		)	(827.3		)
Financing activities
Issuance of common stock	69.6			—			—			—			69.6
Acquisition of treasury stock	(222.5		)	—			—			—			(222.5		)
Proceeds from financing element derivatives	—			—			14.9			—			14.9
Payments for financing element derivatives	—			—			(41.5		)	—			(41.5		)
Excess tax benefits from share-based payment arrangements	0.3			—			8.3			—			8.6
Purchase of subsidiary shares from noncontrolling interest	—			—			(222.4		)	—			(222.4		)
Dividends to common stockholders	(276.7		)	—			—			—			(276.7		)
Dividends to preferred stockholders	(24.7		)	—			—			—			(24.7		)
Issuance of long-term debt	—			—			36.5			—			36.5
Principal repayments of long-term debt	—			—			(100.3		)	—			(100.3		)
Net repayments of short-term borrowings	—			—			(113.5		)	93			(20.5		)
Dividends and capital paid to parent	—			(517.5		)	(714.0		)	1,231.50			—
Investment contract deposits	—			—			4,184.30			—			4,184.30
Investment contract withdrawals	—			—			(5,864.3		)	—			(5,864.3		)
Net decrease in banking operation deposits	—			—			(2.3		)	—			(2.3		)
Other	—			—			(10.0		)	—			(10.0		)
Net cash used in financing activities	(454.0		)	(517.5		)	(2,824.3		)	1,324.50			(2,471.3		)
Net increase (decrease) in cash and cash equivalents	19.2			(275.7		)	(1,187.6		)	343.1			(1,101.0		)
Cash and cash equivalents at beginning of period	131.5			688.7			2,384.00			(832.4		)	2,371.80
Cash and cash equivalents at end of period	$	150.7		$	413		$	1,196.40		$	(489.3	)	$	1,270.80
Condensed Consolidating Statements of Cash Flows
For the nine months ended September 30, 2013
							Principal Life
	Principal			Principal			Insurance						Principal
	Financial			Financial			Company and						Financial
	Group, Inc.			Services, Inc.			Other Subsidiaries						Group, Inc.
	Parent Only			Only			Combined			Eliminations			Consolidated
	(in millions)
Operating activities
Net cash provided by (used in) operating activities	$	(12.8	)	$	870.9		$	1,473.40		$	(933.6	)	$	1,397.90
Investing activities
Available-for-sale securities:
Purchases	—			—			(7,012.3		)	—			(7,012.3		)
Sales	—			—			1,626.70			—			1,626.70
Maturities	—			—			5,783.20			—			5,783.20
Mortgage loans acquired or originated	—			—			(2,020.0		)	—			(2,020.0		)
Mortgage loans sold or repaid	—			—			1,570.80			—			1,570.80
Real estate acquired	—			—			(59.0		)	—			(59.0		)
Net purchases of property and equipment	—			—			(22.7		)	—			(22.7		)
Purchases of interests in subsidiaries, net of cash acquired	—			—			(1,268.3		)	—			(1,268.3		)
Dividends and returns of capital received from (contributions to) unconsolidated entities	169.3			(809.2		)	—			639.9			—
Net change in other investments	(3.2		)	(13.9		)	(14.1		)	—			(31.2		)
Net cash provided by (used in) investing activities	166.1			(823.1		)	(1,415.7		)	639.9			(1,432.8		)
Financing activities
Issuance of common stock	80.2			—			—			—			80.2
Acquisition of treasury stock	(153.4		)	—			—			—			(153.4		)
Proceeds from financing element derivatives	—			—			46.7			—			46.7
Payments for financing element derivatives	—			—			(36.9		)	—			(36.9		)
Excess tax benefits from share-based payment arrangements	—			—			8.6			—			8.6
Purchase of subsidiary shares from noncontrolling interest	—			—			(51.4		)	—			(51.4		)
Sale of subsidiary shares to noncontrolling interest	—			—			31.8			—			31.8
Dividends to common stockholders	(211.7		)	—			—			—			(211.7		)
Dividends to preferred stockholders	(24.7		)	—			—			—			(24.7		)
Issuance of long-term debt	—			—			1,108.40			(1,084.3		)	24.1
Principal repayments of long-term debt	—			—			(212.2		)	—			(212.2		)
Net proceeds from (repayments of) short-term borrowings	—			—			(2,113.2		)	2,244.80			131.6
Dividends and capital received from (paid to) parent	—			(169.3		)	809.2			(639.9		)	—
Investment contract deposits	—			—			5,270.20			—			5,270.20
Investment contract withdrawals	—			—			(7,055.6		)	—			(7,055.6		)
Net decrease in banking operation deposits	—			—			(276.2		)	—			(276.2		)
Other	—			—			(6.3		)	—			(6.3		)
Net cash used in financing activities	(309.6		)	(169.3		)	(2,476.9		)	520.6			(2,435.2		)
Net decrease in cash and cash equivalents	(156.3		)	(121.5		)	(2,419.2		)	226.9			(2,470.1		)
Cash and cash equivalents at beginning of period	207.1			612.5			4,241.30			(883.7		)	4,177.20
Cash and cash equivalents at end of period	$	50.8		$	491		$	1,822.10		$	(656.8	)	$	1,707.10

Nature_of_Operations_and_Signi2

Nature of Operations and Significant Accounting Policies (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Separate Accounts	'	'
Separate account that primarily includes shares of Principal Financial Group, Inc. stock that were allocated and issued to eligible participants of qualified employee benefit plans as part of the 2001 demutualization	$216	$223.10

Variable_Interest_Entities_Det

Variable Interest Entities (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Carrying amounts of consolidated VIE assets and liabilities	'	'
Fixed maturities, available-for-sale	$49,627.50	$48,757.10
Fixed maturities, trading	609.4	563.1
Equity securities, trading	807.6	716.9
Real estate	1,352.10	1,271.60
Other investments	2,990.90	2,944.40
Accrued investment income	545.1	532.1
Separate account assets	138,296.70	130,018.40
Other assets	1,054.70	1,134.20
Total assets	216,422.80	208,191.40
Long-term debt	2,529.20	2,601.40
Deferred income taxes	1,150.60	824
Separate account liabilities	138,296.70	130,018.40
Other liabilities	4,984.60	5,224.20
Total liabilities	205,997.70	198,167.20
Aggregate consolidated variable interest entities	'	'
Carrying amounts of consolidated VIE assets and liabilities	'	'
Fixed maturities, available-for-sale	287.2	272
Fixed maturities, trading	100.4	110.4
Equity securities, trading	349.4	327.2
Real estate	276.2	266.3
Other investments	46.2	68.1
Cash	6.2	12
Accrued investment income	2.1	2
Separate account assets	35,079.90	32,824.70
Other assets	0.2	0.1
Total assets	36,147.80	33,882.80
Long-term debt	74.9	47.7
Deferred income taxes	1.6	1.5
Separate account liabilities	35,079.90	32,824.70
Other liabilities	349.5	362.4
Total liabilities	35,505.90	33,236.30
Grantor trusts	'	'
Consolidated Variable Interest Entity disclosures	'	'
Number of consolidated variable interest entities	3	'
Carrying amounts of consolidated VIE assets and liabilities	'	'
Fixed maturities, available-for-sale	287.2	272
Accrued investment income	0.4	0.3
Total assets	287.6	272.3
Deferred income taxes	1.6	1.5
Other liabilities	242	217.2
Total liabilities	243.6	218.7
Collateralized private investment vehicle	'	'
Consolidated Variable Interest Entity disclosures	'	'
Number of entities for which the reporting entity acts as primary beneficiary	1	'
Carrying amounts of consolidated VIE assets and liabilities	'	'
Fixed maturities, trading	100.4	110.4
Total assets	100.4	110.4
Other liabilities	86.9	93.8
Total liabilities	86.9	93.8
Commercial mortgage-backed securities VIE	'	'
Carrying amounts of consolidated VIE assets and liabilities	'	'
Other investments	41.9	68.1
Accrued investment income	0.2	0.6
Total assets	42.1	68.7
Other liabilities	4.9	31.4
Total liabilities	4.9	31.4
Mandatory retirement savings	'	'
Carrying amounts of consolidated VIE assets and liabilities	'	'
Equity securities, trading	349.4	327.2
Separate account assets	35,079.90	32,824.70
Total assets	35,429.30	33,151.90
Separate account liabilities	35,079.90	32,824.70
Total liabilities	35,079.90	32,824.70
Real estate VIE	'	'
Carrying amounts of consolidated VIE assets and liabilities	'	'
Real estate	276.2	266.3
Other investments	4.3	'
Cash	6.2	12
Accrued investment income	1.5	1.1
Other assets	0.2	0.1
Total assets	288.4	279.5
Long-term debt	74.9	47.7
Other liabilities	15.7	20
Total liabilities	$90.60	$67.70

Variable_Interest_Entities_Det1

Variable Interest Entities (Details 2) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Sponsored Investment Funds	'	'
Total assets of unconsolidated money market mutual fund variable interest entities	$1,400,000,000	$1,400,000,000
Other investments: Other limited partnership interests	'	'
Unconsolidated Variable Interest Entity disclosures	'	'
Asset carrying value	154,500,000	123,500,000
Maximum exposure to loss	154,500,000	123,500,000
Available-for-sale | Corporate debt securities	'	'
Unconsolidated Variable Interest Entity disclosures	'	'
Asset carrying value	493,400,000	523,400,000
Maximum exposure to loss	393,900,000	448,200,000
Available-for-sale | Residential mortgage-backed pass-through securities	'	'
Unconsolidated Variable Interest Entity disclosures	'	'
Asset carrying value	2,809,000,000	2,845,200,000
Maximum exposure to loss	2,714,500,000	2,799,100,000
Available-for-sale | Commercial mortgage-backed securities	'	'
Unconsolidated Variable Interest Entity disclosures	'	'
Asset carrying value	4,012,300,000	4,026,400,000
Maximum exposure to loss	3,925,800,000	4,078,000,000
Available-for-sale | Collateralized debt obligations	'	'
Unconsolidated Variable Interest Entity disclosures	'	'
Asset carrying value	480,800,000	363,400,000
Maximum exposure to loss	493,500,000	391,900,000
Available-for-sale | Other debt obligations	'	'
Unconsolidated Variable Interest Entity disclosures	'	'
Asset carrying value	4,414,400,000	4,167,800,000
Maximum exposure to loss	4,385,000,000	4,157,500,000
Trading | Residential mortgage-backed pass-through securities	'	'
Unconsolidated Variable Interest Entity disclosures	'	'
Asset carrying value	37,300,000	47,500,000
Maximum exposure to loss	37,300,000	47,500,000
Trading | Commercial mortgage-backed securities	'	'
Unconsolidated Variable Interest Entity disclosures	'	'
Asset carrying value	1,400,000	1,800,000
Maximum exposure to loss	1,400,000	1,800,000
Trading | Collateralized debt obligations	'	'
Unconsolidated Variable Interest Entity disclosures	'	'
Asset carrying value	38,900,000	59,600,000
Maximum exposure to loss	38,900,000	59,600,000
Trading | Other debt obligations	'	'
Unconsolidated Variable Interest Entity disclosures	'	'
Asset carrying value	500,000	1,200,000
Maximum exposure to loss	$500,000	$1,200,000

Investments_Details

Investments (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fixed maturities	'	'
Available-for-sale securities disclosures	'	'
Amortized cost	$46,775.80	$47,001.30
Gross unrealized gains	3,172.70	2,562.40
Gross unrealized losses	321	806.6
Fair value	49,627.50	48,757.10
Other-than-temporary impairments in AOCI	194.9	277.5
Net unrealized gains (losses) on impaired fixed maturities, available-for-sale related to changes in fair value subsequent to the impairment date	186.6	148.6
U.S. government and agencies	'	'
Available-for-sale securities disclosures	'	'
Amortized cost	882.2	818.2
Gross unrealized gains	18.3	12.7
Gross unrealized losses	8.4	50.4
Fair value	892.1	780.5
Non-U.S. governments	'	'
Available-for-sale securities disclosures	'	'
Amortized cost	736.7	853.2
Gross unrealized gains	168.9	148.8
Gross unrealized losses	0.9	5.2
Fair value	904.7	996.8
States and political subdivisions	'	'
Available-for-sale securities disclosures	'	'
Amortized cost	3,875.80	3,622.80
Gross unrealized gains	233.9	120.9
Gross unrealized losses	15.7	85.7
Fair value	4,094	3,658
Corporate debt securities	'	'
Available-for-sale securities disclosures	'	'
Amortized cost	29,762.30	30,280.60
Gross unrealized gains	2,414.40	1,958.80
Gross unrealized losses	156.5	320.4
Fair value	32,020.20	31,919
Other-than-temporary impairments in AOCI	19.4	17.1
Residential mortgage-backed pass-through securities	'	'
Available-for-sale securities disclosures	'	'
Amortized cost	2,714.50	2,799.10
Gross unrealized gains	109.8	92.8
Gross unrealized losses	15.3	46.7
Fair value	2,809	2,845.20
Commercial mortgage-backed securities	'	'
Available-for-sale securities disclosures	'	'
Amortized cost	3,925.80	4,078
Gross unrealized gains	164.7	170.6
Gross unrealized losses	78.2	222.2
Fair value	4,012.30	4,026.40
Other-than-temporary impairments in AOCI	105.5	183.4
Collateralized debt obligations	'	'
Available-for-sale securities disclosures	'	'
Amortized cost	493.5	391.9
Gross unrealized gains	7	6
Gross unrealized losses	19.7	34.5
Fair value	480.8	363.4
Other-than-temporary impairments in AOCI	1.2	0.7
Other debt obligations	'	'
Available-for-sale securities disclosures	'	'
Amortized cost	4,385	4,157.50
Gross unrealized gains	55.7	51.8
Gross unrealized losses	26.3	41.5
Fair value	4,414.40	4,167.80
Other-than-temporary impairments in AOCI	68.8	76.3
Equity securities	'	'
Available-for-sale securities disclosures	'	'
Amortized cost	126.8	113.8
Gross unrealized gains	8.4	10
Gross unrealized losses	10.4	13.3
Fair value	$124.80	$110.50

Investments_Details_2

Investments (Details 2) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Amortized cost of fixed maturities available-for-sale	'	'
Due in one year or less	$2,886.80	'
Due after one year through five years	12,618.50	'
Due after five years through ten years	8,167.60	'
Due after ten years	11,584.10	'
Subtotal	35,257	'
Mortgage-backed and other asset-backed securities	11,518.80	'
Total	46,775.80	'
Fair value of fixed maturities available-for-sale	'	'
Due in one year or less	2,924.30	'
Due after one year through five years	13,221.60	'
Due after five years through ten years	8,694.80	'
Due after ten years	13,070.30	'
Subtotal	37,911	'
Mortgage-backed and other asset-backed securities	11,716.50	'
Total	$49,627.50	$48,757.10

Investments_Details_3

Investments (Details 3) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fixed maturities, available-for-sale:	'	'	'	'
Gross gains	$9.60	$5.80	$73.80	$27.60
Gross losses	-13.6	-18.2	-36.6	-98.6
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	-14.6	-9.3	-82.5	8.8
Hedging, net	-21.5	-9.6	-20	-99.4
Fixed maturities, trading	9.5	2.1	32	-4.1
Equity securities, available-for-sale:	'	'	'	'
Gross gains	'	0.7	5.8	0.8
Gross losses	-0.3	'	-0.3	-0.1
Equity securities, trading	9.1	0.1	18.7	11.6
Mortgage loans	-12	-3.3	-10.6	-20.3
Derivatives	-2	-34.8	1.9	-4.8
Other	-10.6	15.6	58.8	-3.4
Net realized capital gains (losses)	-46.4	-50.9	41	-181.9
Proceeds from sales of investments	'	'	'	'
Proceeds from sales of investments in fixed maturities, available-for-sale	$437.10	$413.70	$1,744.60	$1,515.90

Investments_Details_4

Investments (Details 4) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other-than-temporary impairment losses, net of recoveries	'	'	'	'
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	($7.30)	($11.90)	$18.50	($81.20)
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	-14.6	-9.3	-82.5	8.8
Net impairment losses on available-for-sale securities	-21.9	-21.2	-64	-72.4
Fixed maturities	'	'	'	'
Other-than-temporary impairment losses, net of recoveries	'	'	'	'
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	-7.1	-11.9	13	-81.1
Equity securities	'	'	'	'
Other-than-temporary impairment losses, net of recoveries	'	'	'	'
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	($0.20)	'	$5.50	($0.10)

Investments_Details_5

Investments (Details 5) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other-Than-Temporary Impairment Credit Losses Recognized in Net Income - Rollforward	'	'	'	'
Beginning balance	($185.70)	($301.50)	($235.40)	($335.20)
Credit losses for which an other-than-temporary impairment was not previously recognized	-2.2	-4.9	-6.1	-11.1
Credit losses for which an other-than-temporary impairment was previously recognized	-21	-18.9	-65.5	-54
Reduction for credit losses previously recognized on fixed maturities now sold, paid down or intended to be sold	18	14.6	112	83.1
Net reduction (increase) for positive changes in cash flows expected to be collected and amortization	1.5	2.7	5.6	9.2
Ending balance	($189.40)	($308)	($189.40)	($308)

Investments_Details_6

Investments (Details 6) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fixed maturities	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	$4,459.90	$9,313.20
Less than twelve months, Gross unrealized losses	36.6	356.4
Greater than or equal to twelve months, Fair value	3,586.70	2,256
Greater than or equal to twelve months, Gross unrealized losses	284.4	450.2
Total, Fair value	8,046.60	11,569.20
Total, Gross unrealized losses	321	806.6
U.S. government and agencies	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	258.7	526.8
Less than twelve months, Gross unrealized losses	1.2	49.6
Greater than or equal to twelve months, Fair value	210.5	9.2
Greater than or equal to twelve months, Gross unrealized losses	7.2	0.8
Total, Fair value	469.2	536
Total, Gross unrealized losses	8.4	50.4
Non-U.S. governments	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	36	78.1
Less than twelve months, Gross unrealized losses	0.6	5.1
Greater than or equal to twelve months, Fair value	11.6	5.8
Greater than or equal to twelve months, Gross unrealized losses	0.3	0.1
Total, Fair value	47.6	83.9
Total, Gross unrealized losses	0.9	5.2
States and political subdivisions	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	169.8	1,338.60
Less than twelve months, Gross unrealized losses	1.3	75.3
Greater than or equal to twelve months, Fair value	359.5	46.1
Greater than or equal to twelve months, Gross unrealized losses	14.4	10.4
Total, Fair value	529.3	1,384.70
Total, Gross unrealized losses	15.7	85.7
Corporate debt securities	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	2,489.20	4,087.90
Less than twelve months, Gross unrealized losses	24.9	155.4
Greater than or equal to twelve months, Fair value	1,459.50	1,278.10
Greater than or equal to twelve months, Gross unrealized losses	131.6	165
Total, Fair value	3,948.70	5,366
Total, Gross unrealized losses	156.5	320.4
Residential mortgage-backed pass-through securities	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	175.7	1,150.30
Less than twelve months, Gross unrealized losses	0.7	38.2
Greater than or equal to twelve months, Fair value	504.1	85.9
Greater than or equal to twelve months, Gross unrealized losses	14.6	8.5
Total, Fair value	679.8	1,236.20
Total, Gross unrealized losses	15.3	46.7
Commercial mortgage-backed securities	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	315.1	683.7
Less than twelve months, Gross unrealized losses	3	15.3
Greater than or equal to twelve months, Fair value	472.4	495.6
Greater than or equal to twelve months, Gross unrealized losses	75.2	206.9
Total, Fair value	787.5	1,179.30
Total, Gross unrealized losses	78.2	222.2
Collateralized debt obligations	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	147.5	88.8
Less than twelve months, Gross unrealized losses	1.6	1.4
Greater than or equal to twelve months, Fair value	82.9	47.4
Greater than or equal to twelve months, Gross unrealized losses	18.1	33.1
Total, Fair value	230.4	136.2
Total, Gross unrealized losses	19.7	34.5
Other debt obligations	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	867.9	1,359
Less than twelve months, Gross unrealized losses	3.3	16.1
Greater than or equal to twelve months, Fair value	486.2	287.9
Greater than or equal to twelve months, Gross unrealized losses	23	25.4
Total, Fair value	1,354.10	1,646.90
Total, Gross unrealized losses	26.3	41.5
Equity securities	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	'	16.7
Less than twelve months, Gross unrealized losses	'	0.3
Greater than or equal to twelve months, Fair value	50.9	48.3
Greater than or equal to twelve months, Gross unrealized losses	10.4	13
Total, Fair value	50.9	65
Total, Gross unrealized losses	10.4	13.3
Principal Life Insurance Company Only | Fixed maturities	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Less than twelve months, Fair value	4,426	8,899.50
Less than twelve months, Gross unrealized losses	36.4	339.8
Greater than or equal to twelve months, Fair value	3,407.30	2,005.90
Greater than or equal to twelve months, Gross unrealized losses	260.3	412.7
Total, Fair value	7,833.30	10,905.40
Total, Gross unrealized losses	296.7	752.5
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure	'	'
Available-for-sale Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less Than Twelve Months	591	1,154
Available-for-sale Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Twelve Months or Longer	507	359
Available-for-sale Securities in Unrealized Loss Position, Aggregate Losses On Investment Grade Investments, Less Than Twelve Months	24.4	325.9
Available-for-sale Securities in Unrealized Loss Positions, Qualitative Disclosure, Percent Investment Grade (as a percent)	83.00%	87.00%
Available-for-sale Securities in Unrealized Loss Positions, Qualitative Disclosure, Average Price (percent of carrying value to amortized cost)	96	94
Available-for-sale Securities in Unrealized Loss Positions, Percent Investment Grade, Less Than Twelve Months (as a percent)	79.00%	94.00%
Available-for-sale Securities in Unrealized Loss Positions, Average Price, Less Than Twelve Months (percent of carrying value to amortized cost)	99	96
Available-for-sale Securities in Unrealized Loss Positions, Average Price, Twelve Months or Longer (percent of carrying value to amortized cost)	93	83
Principal Life Insurance Company Only | Corporate debt securities	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Greater than or equal to twelve months, Gross unrealized losses	108	127.6
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure	'	'
Available-for-sale Securities in Unrealized Loss Positions, Average Price, Twelve Months or Longer (percent of carrying value to amortized cost)	92	89
Principal Life Insurance Company Only | Commercial mortgage-backed securities	'	'
Gross Unrealized Losses for Fixed Maturities and Equity Securities	'	'
Greater than or equal to twelve months, Gross unrealized losses	$75.20	$206.90
Available-for-sale Securities, Continuous Unrealized Loss Position, Qualitative Disclosure	'	'
Available-for-sale Securities in Unrealized Loss Positions, Average Price, Twelve Months or Longer (percent of carrying value to amortized cost)	86	71

Investments_Details_7

Investments (Details 7) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Net Unrealized Gains and Losses on Available-for-Sale Securities and Derivative Instruments	'	'
Net unrealized gains (losses) on fixed maturities, available-for-sale	$3,021.10	$2,067.40
Noncredit component of impairment losses on fixed maturities, available-for-sale	-194.9	-277.5
Net unrealized gains (losses) on equity securities, available-for-sale	-2	-3.3
Adjustments for assumed changes in amortization patterns	-351.1	-265.9
Adjustments for assumed changes in policyholder liabilities	-1,057	-621.2
Net unrealized gains (losses) on derivative instruments	130	56
Net unrealized gains (losses) on equity method subsidiaries and noncontrolling interest adjustments	84.6	87.1
Provision for deferred income tax benefits (taxes)	-542.3	-342
Net unrealized gains (losses) on available-for-sale securities and derivative instruments	$1,088.40	$700.60

Investments_Details_8

Investments (Details 8) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	$11,802.90	$11,956	$11,802.90	$11,956	'	$11,603.40	'	'
Mortgage loan valuation allowance	-58	-87.9	-58	-87.9	-64.9	-69.8	-94.9	-97.4
Mortgage loans, Total carrying value	11,744.90	'	11,744.90	'	'	11,533.60	'	'
Commercial mortgage loans	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	10,596.80	10,658.30	10,596.80	10,658.30	'	10,327.70	'	'
Mortgage loan valuation allowance	-27.8	-42.4	-27.8	-42.4	-26.4	-28.7	-47.7	-51.8
Mortgage loans, purchased	0	0	33.4	141.1	'	'	'	'
Mortgage loans, sold	0	0	1.1	13	'	'	'	'
Percent of mortgage loans (as a percent)	100.00%	'	100.00%	'	'	100.00%	'	'
Commercial mortgage loans | Office	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	3,461.50	'	3,461.50	'	'	3,360.50	'	'
Percent of mortgage loans (as a percent)	32.70%	'	32.70%	'	'	32.60%	'	'
Commercial mortgage loans | Retail	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	2,463	'	2,463	'	'	2,668.50	'	'
Percent of mortgage loans (as a percent)	23.20%	'	23.20%	'	'	25.80%	'	'
Commercial mortgage loans | Industrial	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	1,942.20	'	1,942.20	'	'	1,766.20	'	'
Percent of mortgage loans (as a percent)	18.30%	'	18.30%	'	'	17.10%	'	'
Commercial mortgage loans | Apartments	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	2,065.20	'	2,065.20	'	'	1,911.20	'	'
Percent of mortgage loans (as a percent)	19.50%	'	19.50%	'	'	18.50%	'	'
Commercial mortgage loans | Hotel	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	337.1	'	337.1	'	'	333.1	'	'
Percent of mortgage loans (as a percent)	3.20%	'	3.20%	'	'	3.20%	'	'
Commercial mortgage loans | Mixed use/other	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	327.8	'	327.8	'	'	288.2	'	'
Percent of mortgage loans (as a percent)	3.10%	'	3.10%	'	'	2.80%	'	'
Commercial mortgage loans | New England	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	508.6	'	508.6	'	'	528.5	'	'
Percent of mortgage loans (as a percent)	4.80%	'	4.80%	'	'	5.10%	'	'
Commercial mortgage loans | Middle Atlantic	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	2,798.30	'	2,798.30	'	'	2,489	'	'
Percent of mortgage loans (as a percent)	26.40%	'	26.40%	'	'	24.10%	'	'
Commercial mortgage loans | East North Central	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	462.4	'	462.4	'	'	519.9	'	'
Percent of mortgage loans (as a percent)	4.40%	'	4.40%	'	'	5.00%	'	'
Commercial mortgage loans | West North Central	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	253	'	253	'	'	302.9	'	'
Percent of mortgage loans (as a percent)	2.40%	'	2.40%	'	'	2.90%	'	'
Commercial mortgage loans | South Atlantic	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	1,944.60	'	1,944.60	'	'	1,949.50	'	'
Percent of mortgage loans (as a percent)	18.40%	'	18.40%	'	'	18.90%	'	'
Commercial mortgage loans | East South Central	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	199.6	'	199.6	'	'	192.8	'	'
Percent of mortgage loans (as a percent)	1.90%	'	1.90%	'	'	1.90%	'	'
Commercial mortgage loans | West South Central	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	1,003.60	'	1,003.60	'	'	830.3	'	'
Percent of mortgage loans (as a percent)	9.50%	'	9.50%	'	'	8.00%	'	'
Commercial mortgage loans | Mountain	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	755.6	'	755.6	'	'	747.1	'	'
Percent of mortgage loans (as a percent)	7.10%	'	7.10%	'	'	7.20%	'	'
Commercial mortgage loans | Pacific	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	2,631.10	'	2,631.10	'	'	2,722.50	'	'
Percent of mortgage loans (as a percent)	24.70%	'	24.70%	'	'	26.50%	'	'
Commercial mortgage loans | International	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	40	'	40	'	'	45.2	'	'
Percent of mortgage loans (as a percent)	0.40%	'	0.40%	'	'	0.40%	'	'
Residential mortgage loans	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	1,206.10	1,297.70	1,206.10	1,297.70	'	1,275.70	'	'
Mortgage loan valuation allowance	-30.2	-45.5	-30.2	-45.5	-38.5	-41.1	-47.2	-45.6
Mortgage loans, purchased	35.6	64.8	115.7	135.8	'	'	'	'
Mortgage loans, sold	0	0	0	0	'	'	'	'
Home equity	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	322.4	'	322.4	'	'	394.9	'	'
First liens	'	'	'	'	'	'	'	'
Mortgage loan disclosures	'	'	'	'	'	'	'	'
Mortgage loans, Total amortized cost	$883.70	'	$883.70	'	'	$880.80	'	'

Investments_Details_9

Investments (Details 9) (USD $)

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

In Millions, unless otherwise specified

Commercial mortgage loans

Commercial mortgage loans

Commercial mortgage loans

Commercial mortgage loans

Commercial mortgage loans

Commercial mortgage loans

Commercial mortgage loans

Commercial mortgage loans

Commercial mortgage loans

Commercial mortgage loans

Commercial mortgage loans

Brick and mortar

Brick and mortar

Brick and mortar

Brick and mortar

Brick and mortar

Brick and mortar

Brick and mortar

Brick and mortar

Brick and mortar

Brick and mortar

Credit tenant loans

Credit tenant loans

Credit tenant loans

Credit tenant loans

Credit tenant loans

Credit tenant loans

Credit tenant loans

Credit tenant loans

Credit tenant loans

Residential mortgage loans

Residential mortgage loans

Residential mortgage loans

Residential mortgage loans

Residential mortgage loans

Residential mortgage loans

Residential mortgage loans

Home equity

Home equity

Home equity

Home equity

Home equity

Home equity

First liens

First liens

First liens

First liens

First liens

First liens

A- and above

A- and above

BBB+ thru BBB-

BBB+ thru BBB-

BB+ thru BB-

BB+ thru BB-

B+ and below

B+ and below

A- and above

A- and above

BBB+ thru BBB-

BBB+ thru BBB-

BB+ thru BB-

BB+ thru BB-

B+ and below

B+ and below

A- and above

A- and above

BBB+ thru BBB-

BBB+ thru BBB-

BB+ thru BB-

B+ and below

B+ and below

Performing

Performing

Nonperforming

Nonperforming

Performing

Performing

Nonperforming

Nonperforming

Performing

Performing

Nonperforming

Nonperforming

Mortgage loan credit quality disclosures

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Mortgage loans, Total amortized cost

$11,802.90

$11,603.40

$11,956

$10,596.80

$10,327.70

$10,658.30

$8,941.50

$8,286.40

$1,407

$1,713.70

$181.90

$155.50

$66.40

$172.10

$10,220.70

$9,881.10

$8,762.30

$8,091.90

$1,211.80

$1,463.70

$181.90

$155.40

$64.70

$170.10

$376.10

$446.60

$179.20

$194.50

$195.20

$250

$0.10

$1.70

$2

$1,206.10

$1,275.70

$1,297.70

$1,175.40

$1,240.40

$30.70

$35.30

$322.40

$394.90

$307.30

$378.30

$15.10

$16.60

$883.70

$880.80

$868.10

$862.10

$15.60

$18.70

Mortgage loans, Days delinquent to be considered nonperforming

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'90 days

'90 days

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Investments_Details_10

Investments (Details 10) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
In Millions, unless otherwise specified
Mortgage loan non-accrual and aging disclosures	'	'	'
Mortgage loans, Non-accrual status	$35.60	$61.20	'
30-59 days past due	26.3	36.8	'
60-89 days past due	7.2	8.4	'
90 days or more past due	18	36.8	'
Total past due	51.5	82	'
Current	11,751.40	11,521.40	'
Mortgage loans, Total amortized cost	11,802.90	11,603.40	11,956
Recorded investment 90 days or more past due and accruing	5.8	7.3	'
Commercial mortgage loans	'	'	'
Mortgage loan non-accrual and aging disclosures	'	'	'
Mortgage loans, Total amortized cost	10,596.80	10,327.70	10,658.30
Brick and mortar	'	'	'
Mortgage loan non-accrual and aging disclosures	'	'	'
Mortgage loans, Non-accrual status	10.7	33.2	'
90 days or more past due	0.9	16.7	'
Total past due	0.9	16.7	'
Current	10,219.80	9,864.40	'
Mortgage loans, Total amortized cost	10,220.70	9,881.10	'
Credit tenant loans	'	'	'
Mortgage loan non-accrual and aging disclosures	'	'	'
Current	376.1	446.6	'
Mortgage loans, Total amortized cost	376.1	446.6	'
Residential mortgage loans	'	'	'
Mortgage loan non-accrual and aging disclosures	'	'	'
Mortgage loans, Total amortized cost	1,206.10	1,275.70	1,297.70
Home equity	'	'	'
Mortgage loan non-accrual and aging disclosures	'	'	'
Mortgage loans, Non-accrual status	15.1	16.6	'
30-59 days past due	2.5	4.4	'
60-89 days past due	2.4	1	'
90 days or more past due	2.2	3	'
Total past due	7.1	8.4	'
Current	315.3	386.5	'
Mortgage loans, Total amortized cost	322.4	394.9	'
First liens	'	'	'
Mortgage loan non-accrual and aging disclosures	'	'	'
Mortgage loans, Non-accrual status	9.8	11.4	'
30-59 days past due	23.8	32.4	'
60-89 days past due	4.8	7.4	'
90 days or more past due	14.9	17.1	'
Total past due	43.5	56.9	'
Current	840.2	823.9	'
Mortgage loans, Total amortized cost	883.7	880.8	'
Recorded investment 90 days or more past due and accruing	$5.80	$7.30	'

Investments_Details_11

Investments (Details 11) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Changes in mortgage loan valuation allowance	'	'	'	'	'
Beginning balance, Mortgage loan valuation allowance	$64.90	$94.90	$69.80	$97.40	'
Provision: Mortgage loan valuation allowance	7.9	2	6.7	19.3	'
Charge-offs: Mortgage loan valuation allowance	-15.1	-9.9	-21.1	-31.9	'
Recoveries: Mortgage loan valuation allowance	0.3	0.9	2.7	3.2	'
Effect of exchange rates: Mortgage loan valuation allowance	'	'	-0.1	-0.1	'
Ending balance, Mortgage loan valuation allowance	58	87.9	58	87.9	'
Individually evaluated for impairment, Mortgage loan valuation allowance	12.5	18.9	12.5	18.9	'
Collectively evaluated for impairment, Mortgage loan valuation allowance	45.5	69	45.5	69	'
Individually evaluated for impairment, Mortgage loans	39.4	65.4	39.4	65.4	'
Collectively evaluated for impairment, Mortgage loans	11,763.50	11,890.60	11,763.50	11,890.60	'
Mortgage loans, Total amortized cost	11,802.90	11,956	11,802.90	11,956	11,603.40
Commercial mortgage loans	'	'	'	'	'
Mortgage loan valuation allowance disclosures	'	'	'	'	'
Mortgage loans, Days delinquent to be analyzed for valuation allowance	'	'	'60 days	'	'
Changes in mortgage loan valuation allowance	'	'	'	'	'
Beginning balance, Mortgage loan valuation allowance	26.4	47.7	28.7	51.8	'
Provision: Mortgage loan valuation allowance	1.4	0.7	-0.6	6.7	'
Charge-offs: Mortgage loan valuation allowance	'	-6.2	-0.3	-16.9	'
Recoveries: Mortgage loan valuation allowance	'	0.2	'	0.8	'
Ending balance, Mortgage loan valuation allowance	27.8	42.4	27.8	42.4	'
Individually evaluated for impairment, Mortgage loan valuation allowance	3.1	8.5	3.1	8.5	'
Collectively evaluated for impairment, Mortgage loan valuation allowance	24.7	33.9	24.7	33.9	'
Individually evaluated for impairment, Mortgage loans	9.8	30.7	9.8	30.7	'
Collectively evaluated for impairment, Mortgage loans	10,587	10,627.60	10,587	10,627.60	'
Mortgage loans, Total amortized cost	10,596.80	10,658.30	10,596.80	10,658.30	10,327.70
Residential mortgage loans	'	'	'	'	'
Changes in mortgage loan valuation allowance	'	'	'	'	'
Beginning balance, Mortgage loan valuation allowance	38.5	47.2	41.1	45.6	'
Provision: Mortgage loan valuation allowance	6.5	1.3	7.3	12.6	'
Charge-offs: Mortgage loan valuation allowance	-15.1	-3.7	-20.8	-15	'
Recoveries: Mortgage loan valuation allowance	0.3	0.7	2.7	2.4	'
Effect of exchange rates: Mortgage loan valuation allowance	'	'	-0.1	-0.1	'
Ending balance, Mortgage loan valuation allowance	30.2	45.5	30.2	45.5	'
Individually evaluated for impairment, Mortgage loan valuation allowance	9.4	10.4	9.4	10.4	'
Collectively evaluated for impairment, Mortgage loan valuation allowance	20.8	35.1	20.8	35.1	'
Individually evaluated for impairment, Mortgage loans	29.6	34.7	29.6	34.7	'
Collectively evaluated for impairment, Mortgage loans	1,176.50	1,263	1,176.50	1,263	'
Mortgage loans, Total amortized cost	$1,206.10	$1,297.70	$1,206.10	$1,297.70	$1,275.70

Investments_Details_12

Investments (Details 12) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Commercial mortgage loans	'	'	'	'	'
Impaired mortgage loans	'	'	'	'	'
Recorded investment in impaired mortgage loans	$10.70	'	$10.70	'	$25.90
Unpaid principal balance of impaired mortgage loans	12	'	12	'	37.1
Related allowance for impaired mortgage loans	3.1	'	3.1	'	2.4
Average investment in impaired mortgage loans	8	34.8	18.3	33.7	'
Interest income recognized on impaired mortgage loans	0.1	0.2	0.3	0.4	'
Brick and mortar	'	'	'	'	'
Impaired mortgage loans	'	'	'	'	'
Recorded investment in impaired mortgage loans with no related allowance	0.9	'	0.9	'	21.5
Recorded investment in impaired mortgage loans with related allowance	9.8	'	9.8	'	4.4
Unpaid principal balance of impaired mortgage loans with no related allowance	2.2	'	2.2	'	32.7
Unpaid principal balance of impaired mortgage loans with related allowance	9.8	'	9.8	'	4.4
Related allowance for impaired mortgage loans	3.1	'	3.1	'	2.4
Average investment in impaired mortgage loans with no related allowance	0.9	6.4	11.2	16.2	'
Average investment in impaired mortgage loans with related allowance	7.1	28.4	7.1	17.5	'
Interest income recognized on impaired mortgage loans with no related allowance	'	0.1	0.1	0.2	'
Interest income recognized on impaired mortgage loans with related allowance	0.1	0.1	0.2	0.2	'
Residential mortgage loans	'	'	'	'	'
Impaired mortgage loans	'	'	'	'	'
Recorded investment in impaired mortgage loans	29.6	'	29.6	'	33
Unpaid principal balance of impaired mortgage loans	31.1	'	31.1	'	32.1
Related allowance for impaired mortgage loans	9.4	'	9.4	'	10.2
Average investment in impaired mortgage loans	30.1	35.7	31.4	37.2	'
Interest income recognized on impaired mortgage loans	0.2	0.4	0.6	0.9	'
Home equity	'	'	'	'	'
Impaired mortgage loans	'	'	'	'	'
Recorded investment in impaired mortgage loans with related allowance	17.6	'	17.6	'	19.5
Unpaid principal balance of impaired mortgage loans with related allowance	19.2	'	19.2	'	19.7
Related allowance for impaired mortgage loans	8.5	'	8.5	'	9.2
Average investment in impaired mortgage loans with related allowance	18	20.2	18.6	20.3	'
Interest income recognized on impaired mortgage loans with related allowance	0.2	0.4	0.5	0.8	'
First liens	'	'	'	'	'
Impaired mortgage loans	'	'	'	'	'
Recorded investment in impaired mortgage loans with no related allowance	4	'	4	'	4.6
Recorded investment in impaired mortgage loans with related allowance	8	'	8	'	8.9
Unpaid principal balance of impaired mortgage loans with no related allowance	4	'	4	'	4.6
Unpaid principal balance of impaired mortgage loans with related allowance	7.9	'	7.9	'	7.8
Related allowance for impaired mortgage loans	0.9	'	0.9	'	1
Average investment in impaired mortgage loans with no related allowance	4.1	6.2	4.3	7.9	'
Average investment in impaired mortgage loans with related allowance	8	9.3	8.5	9	'
Interest income recognized on impaired mortgage loans with related allowance	'	'	$0.10	$0.10	'

Investments_Details_13

Investments (Details 13) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
	item	item	item	item
Mortgage Loan Modifications	'	'	'	'
Number of mortgage loans modified as a troubled debt restructuring	39	12	80	65
Recorded investment of mortgage loans modified as a troubled debt restructuring	$7	$0.80	$13.50	$4.60
Number of mortgage loans modified as a troubled debt restructuring in payment default	2	1	4	16
Recorded investment of mortgage loans modified as a troubled debt restructuring in payment default	0.7	0.1	0.7	0.8
Brick and mortar	'	'	'	'
Mortgage Loan Modifications	'	'	'	'
Number of mortgage loans modified as a troubled debt restructuring	2	'	4	2
Recorded investment of mortgage loans modified as a troubled debt restructuring	5.4	'	10.5	0.9
Number of mortgage loans modified as a troubled debt restructuring in payment default	1	'	1	'
Recorded investment of mortgage loans modified as a troubled debt restructuring in payment default	0.7	'	0.7	'
Home equity	'	'	'	'
Mortgage Loan Modifications	'	'	'	'
Number of mortgage loans modified as a troubled debt restructuring	37	12	75	60
Recorded investment of mortgage loans modified as a troubled debt restructuring	1.6	0.8	2.9	3.1
Number of mortgage loans modified as a troubled debt restructuring in payment default	1	'	3	13
First liens	'	'	'	'
Mortgage Loan Modifications	'	'	'	'
Number of mortgage loans modified as a troubled debt restructuring	'	'	1	3
Recorded investment of mortgage loans modified as a troubled debt restructuring	'	'	0.1	0.6
Number of mortgage loans modified as a troubled debt restructuring in payment default	'	1	'	3
Recorded investment of mortgage loans modified as a troubled debt restructuring in payment default	'	$0.10	'	$0.80

Investments_Details_14

Investments (Details 14) (USD $)	Sep. 30, 2014
In Millions, unless otherwise specified
Securities Posted as Collateral	'
Fixed maturity securities posted as collateral for a reinsurance arrangement, derivative credit support annex (collateral) agreements, Futures Commission Merchant agreements, a lending arrangement and an obligation under funding agreements with the Federal Home Loan Bank of Des Moines	$1,344.70
Commercial mortgage loans and home equity mortgages posted as collateral associated with obligation under funding agreements with the Federal Home Loan Bank of Des Moines	2,074.30
Securities posted as collateral eligible to be sold or repledged	$170.90

Investments_Details_15

Investments (Details 15) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Financial Asset Offsetting	'	'
Gross amount of recognized assets subject to netting agreements	$609.50	$716.70
Amount of liabilities that offset the gross amount of assets subject to netting agreements not offset in statement of financial position	-451	-581.5
Collateral received, financial assets	-140.6	-133.9
Net amount of assets subject to netting agreements	17.9	1.3
Derivative assets	'	'
Financial Asset Offsetting	'	'
Gross amount of recognized assets subject to netting agreements	558.7	664.9
Amount of liabilities that offset the gross amount of assets subject to netting agreements not offset in statement of financial position	-451	-581.5
Collateral received, financial assets	-89.8	-82.1
Net amount of assets subject to netting agreements	17.9	1.3
Gross amount of assets not subject to netting agreements	0	0.2
Reverse repurchase agreements	'	'
Financial Asset Offsetting	'	'
Gross amount of recognized assets subject to netting agreements	50.8	51.8
Collateral received, financial assets	($50.80)	($51.80)

Investments_Details_16

Investments (Details 16) (Derivative liabilities, USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivative liabilities	'	'
Financial Liability Offsetting	'	'
Gross amount of recognized liabilities subject to netting agreements	$789.30	$1,022
Amount of assets that offset the gross amount of liabilities subject to netting agreements not offset in statement of financial position	-451	-581.5
Collateral pledged, financial liabilities	-239.9	-362.1
Net amount of liabilities subject to netting agreements	98.4	78.4
Gross amount of liabilities not subject to netting agreements	$341.40	$226.70

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Derivative Financial Instruments, exposure	'	'
Cash and securities posted under collateral arrangements associated with derivative credit support agreements and Futures Commission Merchant agreements	$276.60	$393.10
Aggregate fair value of all derivative instruments with credit-risk-related contingent features that were in a liability position	676.5	1,042.90
Collateral and initial margin posted supporting derivatives with credit-risk-related contingent features that were in a liability position	276.6	393.1
Additional collateral required to be posted if derivative credit-risk-related contingent features were triggered	65.3	'
Cash collateral received associated with derivative credit support annex agreements and Futures Commission Merchant agreements	72.4	32.5
Notional amount	40,173.10	38,840.30
Gross credit exposure	589.3	720.1
Less: collateral received	108.9	115.9
Net credit exposure	480.4	604.2
Interest rate swaps	'	'
Derivative Financial Instruments, exposure	'	'
Cash exchanged under contract	0	'
Principal payments made under contract	0	'
Notional amount	18,747.50	20,570.80
Gross credit exposure	424.2	435.5
Interest rate options	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	4,900	4,100
Gross credit exposure	38.2	42.5
Swaptions	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	260	325
Gross credit exposure	0.1	1
Interest rate futures	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	139.5	92.5
Currency swaps	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	2,034.50	2,367.50
Gross credit exposure	93.6	200.9
Currency forwards	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	264	247.4
Gross credit exposure	'	0.6
Equity options	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	2,967.80	2,010.40
Gross credit exposure	20.4	30
Equity futures	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	422.5	273.3
Credit default swaps	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	1,280.60	1,153.20
Gross credit exposure	12.5	9.5
Total return swaps	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	70	90
Gross credit exposure	0.3	0.1
Credit Futures	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	28.1	9.1
Embedded derivative financial instruments	'	'
Derivative Financial Instruments, exposure	'	'
Notional amount	$9,058.60	$7,601.10

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Details 2) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivatives, fair value disclosures	'	'
Total derivative instruments, assets	$558.70	$665.10
Total derivative instruments, liabilities	1,130.70	1,248.70
Fair value of embedded derivative liabilities reported with contractholder funds	94.1	6.9
Derivatives designated as hedging instrument	'	'
Derivatives, fair value disclosures	'	'
Total derivative instruments, assets	70.7	121.7
Total derivative instruments, liabilities	244.9	336.6
Derivatives not designated as hedging instrument	'	'
Derivatives, fair value disclosures	'	'
Total derivative instruments, assets	488	543.4
Total derivative instruments, liabilities	885.8	912.1
Interest rate contracts | Derivatives designated as hedging instrument	'	'
Derivatives, fair value disclosures	'	'
Total derivative instruments, assets	0.5	0.1
Total derivative instruments, liabilities	201.8	285.4
Interest rate contracts | Derivatives not designated as hedging instrument	'	'
Derivatives, fair value disclosures	'	'
Total derivative instruments, assets	425.6	452.2
Total derivative instruments, liabilities	327.9	489.6
Foreign exchange contracts | Derivatives designated as hedging instrument	'	'
Derivatives, fair value disclosures	'	'
Total derivative instruments, assets	70.2	121.6
Total derivative instruments, liabilities	43.1	51.2
Foreign exchange contracts | Derivatives not designated as hedging instrument	'	'
Derivatives, fair value disclosures	'	'
Total derivative instruments, assets	29.2	51.6
Total derivative instruments, liabilities	39.2	17.9
Equity contracts | Derivatives not designated as hedging instrument	'	'
Derivatives, fair value disclosures	'	'
Total derivative instruments, assets	20.4	30
Total derivative instruments, liabilities	148.1	145
Credit contracts | Derivatives not designated as hedging instrument	'	'
Derivatives, fair value disclosures	'	'
Total derivative instruments, assets	12.8	9.6
Total derivative instruments, liabilities	34.5	35.5
Other contracts | Derivatives not designated as hedging instrument	'	'
Derivatives, fair value disclosures	'	'
Total derivative instruments, liabilities	$336.10	$224.10

Derivative_Financial_Instrumen4

Derivative Financial Instruments (Details 3) (USD $)	9 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Credit derivatives sold disclosures	'	'
Reduction in total maximum future payments due to purchased credit protection	$34.90	$44.90
Net asset (liability) fair value of purchased credit derivative transactions	-0.4	-0.5
Notional amount	978.9	818.9
Fair value	-13.7	-19.2
Maximum future payments	978.9	818.9
Weighted average expected life	'3 years 6 months	'3 years 10 months 24 days
Single name credit default swaps	'	'
Credit derivatives sold disclosures	'	'
Notional amount	823.5	653.5
Fair value	11.4	5.1
Maximum future payments	823.5	653.5
Weighted average expected life	'3 years 8 months 12 days	'4 years
Single name credit default swaps | Corporate debt securities | AAA	'	'
Credit derivatives sold disclosures	'	'
Notional amount	30	10
Fair value	1	0.3
Maximum future payments	30	10
Weighted average expected life	'4 years 6 months	'4 years 8 months 12 days
Single name credit default swaps | Corporate debt securities | AA	'	'
Credit derivatives sold disclosures	'	'
Notional amount	99	84
Fair value	1.8	1.8
Maximum future payments	99	84
Weighted average expected life	'3 years 8 months 12 days	'4 years
Single name credit default swaps | Corporate debt securities | A	'	'
Credit derivatives sold disclosures	'	'
Notional amount	294.5	294.5
Fair value	4.4	4.2
Maximum future payments	294.5	294.5
Weighted average expected life	'3 years 6 months	'4 years
Single name credit default swaps | Corporate debt securities | BBB	'	'
Credit derivatives sold disclosures	'	'
Notional amount	385	265
Fair value	4.6	-1.2
Maximum future payments	385	265
Weighted average expected life	'3 years 10 months 24 days	'3 years 10 months 24 days
Single name credit default swaps | Corporate debt securities | BB	'	'
Credit derivatives sold disclosures	'	'
Notional amount	15	'
Fair value	-0.4	'
Maximum future payments	15	'
Weighted average expected life	'3 years 8 months 12 days	'
Basket and index credit default swaps	'	'
Credit derivatives sold disclosures	'	'
Notional amount	155.4	165.4
Fair value	-25.1	-24.3
Maximum future payments	155.4	165.4
Weighted average expected life	'2 years 7 months 6 days	'3 years 4 months 24 days
Basket and index credit default swaps | Corporate debt securities | Near default	'	'
Credit derivatives sold disclosures	'	'
Notional amount	100.4	110.4
Fair value	-22.5	-19.9
Maximum future payments	100.4	110.4
Weighted average expected life	'2 years 6 months	'3 years 2 months 12 days
Notional amount of derivative whose credit risk is borne by third party investors	78	88
Basket and index credit default swaps | Government/municipalities | AA	'	'
Credit derivatives sold disclosures	'	'
Notional amount	30	30
Fair value	-2.3	-3.5
Maximum future payments	30	30
Weighted average expected life	'3 years	'3 years 8 months 12 days
Basket and index credit default swaps | Structured finance | BBB	'	'
Credit derivatives sold disclosures	'	'
Notional amount	25	25
Fair value	-0.3	-0.9
Maximum future payments	$25	$25
Weighted average expected life	'2 years 9 months 18 days	'3 years 6 months

Derivative_Financial_Instrumen5

Derivative Financial Instruments (Details 4) (USD $)	9 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Derivative Financial Instruments	'	'
Future potential payments in the event of default of an investment in fixed maturity securities that contain embedded credit derivatives	$0	'
Hybrid instruments disclosures	'	'
Amortized cost	88.8	74.6
Carrying value	88.8	73.2
Weighted average expected life	'2 years 4 months 24 days	'4 years
Corporate debt securities	'	'
Hybrid instruments disclosures	'	'
Amortized cost	23.8	23.4
Carrying value	23.8	23.4
Weighted average expected life	'2 years 3 months 18 days	'3 years
Corporate debt securities | A	'	'
Hybrid instruments disclosures	'	'
Amortized cost	23.8	'
Carrying value	23.8	'
Weighted average expected life	'2 years 3 months 18 days	'
Corporate debt securities | BBB	'	'
Hybrid instruments disclosures	'	'
Amortized cost	'	23.4
Carrying value	'	23.4
Weighted average expected life	'	'3 years
Structured finance	'	'
Hybrid instruments disclosures	'	'
Amortized cost	65	51.2
Carrying value	65	49.8
Weighted average expected life	'2 years 6 months	'4 years 6 months
Structured finance | A	'	'
Hybrid instruments disclosures	'	'
Amortized cost	49.8	18.1
Carrying value	49.8	16.7
Weighted average expected life	'2 years 1 month 6 days	'4 years 9 months 18 days
Structured finance | BB	'	'
Hybrid instruments disclosures	'	'
Amortized cost	5.8	5.5
Carrying value	5.8	5.5
Weighted average expected life	'2 years 8 months 12 days	'3 years 3 months 18 days
Structured finance | B	'	'
Hybrid instruments disclosures	'	'
Amortized cost	'	4.1
Carrying value	'	4.1
Weighted average expected life	'	'3 years 1 month 6 days
Structured finance | CCC	'	'
Hybrid instruments disclosures	'	'
Amortized cost	9.4	23.5
Carrying value	$9.40	$23.50
Weighted average expected life	'4 years 3 months 18 days	'4 years 9 months 18 days

Derivative_Financial_Instrumen6

Derivative Financial Instruments (Details 5) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Effect of derivatives in fair value hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	$19.10	$49.70	$31.40	$73.20
Amount of gain (loss) recognized in net income on related hedged item	-19	-49.3	-32.5	-68.2
Fair Value Hedges	'	'	'	'
Effect of derivatives in fair value hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Gain (loss) on periodic settlements on interest rate and foreign exchange contracts in fair value hedge of fixed maturities, available-for-sale reported in net investment income	-22.2	-30.9	-71.5	-92.1
Gain (loss) on periodic settlements on interest rate and foreign exchange contracts in fair value hedge of investment-type insurance contracts reported in benefits, claims and settlement expenses	1	9.9	3.4	29.2
Fair Value Hedges | Interest rate contracts | Fixed maturities, available-for-sale	'	'	'	'
Effect of derivatives in fair value hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	18.5	14.6	27.2	110.9
Amount of gain (loss) recognized in net income on related hedged item	-18.3	-14.1	-28.4	-105.4
Fair Value Hedges | Interest rate contracts | Investment-type insurance contracts	'	'	'	'
Effect of derivatives in fair value hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	-2.4	1.2	0.2	1.2
Amount of gain (loss) recognized in net income on related hedged item	2.4	-1.5	-0.1	-1.5
Fair Value Hedges | Foreign exchange contracts | Fixed maturities, available-for-sale	'	'	'	'
Effect of derivatives in fair value hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	3	-1.1	3.8	0.2
Amount of gain (loss) recognized in net income on related hedged item	-3.1	1.2	-3.8	'
Fair Value Hedges | Foreign exchange contracts | Investment-type insurance contracts	'	'	'	'
Effect of derivatives in fair value hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	'	35	0.2	-39.1
Amount of gain (loss) recognized in net income on related hedged item	'	($34.90)	($0.20)	$38.70

Derivative_Financial_Instrumen7

Derivative Financial Instruments (Details 6) (Cash Flow Hedges, USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Effect of derivatives in cash flow hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Maximum length of time hedging exposure to variability in future cash flows for forecasted transactions	'	'	'5 years 8 months 12 days	'
Gross unrealized gains (losses) reported in accumulated OCI related to active hedges of forecasted transactions	$63.20	'	$63.20	'
Gross unrealized gains (losses) reclassified from accumulated OCI into net income due to forecasted transaction probable of not occurring	'	'	0	0.2
Amount of gain (loss) recognized in accumulated OCI on derivatives (effective portion)	54.9	-51.5	67.6	-50.6
Amount of gain (loss) reclassified from accumulated OCI on derivatives (effective portion)	1.8	-1.9	-6.3	-1.6
Gain (loss) on periodic settlements on interest rate and foreign exchange contracts in cash flow hedge of fixed maturities, available-for-sale reported in net investment income	1.1	1.9	3.9	6.2
Gain (loss) on periodic settlements on interest rate and foreign exchange contracts in cash flow hedge of investment-type insurance contracts reported in benefits, claims and settlement expenses	-2.6	-2.7	-8.4	-8.2
Net gains (losses) expected to be reclassified from accumulated OCI into net income in the next 12 months	'	'	1.7	'
Interest rate contracts | Fixed maturities, available-for-sale | Net investment income	'	'	'	'
Effect of derivatives in cash flow hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in accumulated OCI on derivatives (effective portion)	8.8	-10.2	10.8	-51.4
Amount of gain (loss) reclassified from accumulated OCI on derivatives (effective portion)	3.5	3	10.1	8.6
Interest rate contracts | Investment-type insurance contracts | Benefits, claims and settlement expenses	'	'	'	'
Effect of derivatives in cash flow hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in accumulated OCI on derivatives (effective portion)	0.2	0.6	2.6	1.7
Interest rate contracts | Hedged debt | Operating expense	'	'	'	'
Effect of derivatives in cash flow hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) reclassified from accumulated OCI on derivatives (effective portion)	-1.9	-1.7	-5.5	-4.9
Foreign exchange contracts | Net realized capital gains (losses)	'	'	'	'
Effect of derivatives in cash flow hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Gain (loss) resulting from the ineffective portion in cash flow hedging relationships	0.1	0.1	0	0.5
Foreign exchange contracts | Fixed maturities, available-for-sale | Net realized capital gains (losses)	'	'	'	'
Effect of derivatives in cash flow hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in accumulated OCI on derivatives (effective portion)	44.6	-44.7	44.4	-3.1
Amount of gain (loss) reclassified from accumulated OCI on derivatives (effective portion)	0.2	-3.2	-10.9	-5.3
Foreign exchange contracts | Investment-type insurance contracts | Benefits, claims and settlement expenses	'	'	'	'
Effect of derivatives in cash flow hedging relationships and the related hedged items on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in accumulated OCI on derivatives (effective portion)	$1.30	$2.80	$9.80	$2.20

Derivative_Financial_Instrumen8

Derivative Financial Instruments (Details 7) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Effect of derivatives not designated as hedging instruments on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	($51.40)	($25.30)	($41.10)	($78.80)
Interest rate contracts	'	'	'	'
Effect of derivatives not designated as hedging instruments on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	38.3	-20	134.7	-112.1
Foreign exchange contracts	'	'	'	'
Effect of derivatives not designated as hedging instruments on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	-43.7	14.9	-56.6	3.1
Equity contracts	'	'	'	'
Effect of derivatives not designated as hedging instruments on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	37.7	-49	0.1	-120.5
Credit contracts	'	'	'	'
Effect of derivatives not designated as hedging instruments on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	-21.7	10.4	-10.8	32.8
Other contracts	'	'	'	'
Effect of derivatives not designated as hedging instruments on the consolidated statements of operations	'	'	'	'
Amount of gain (loss) recognized in net income on derivatives	($62)	$18.40	($108.50)	$117.90

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended			9 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Income Taxes	'	'	'	'	'	'
U.S. corporate statutory income tax rate (as a percent)	35.00%	'	35.00%	35.00%	35.00%	'
Increase in net deferred tax liabilities resulting from enactment of tax legislation	$58.10	'	'	$58.10	'	'
Impact of court ruling on uncertain tax positions	'	-47.5	'	'	'	'
Changes in Unrecognized Tax Benefits	'	'	'	'	'	'
Beginning balance, Unrecognized tax benefits	'	'	'	108.9	119.5	119.5
Additions based on tax positions related to the current year	'	'	'	9.4	'	10.5
Additions for tax positions of prior years	'	'	'	64.4	'	10.9
Reductions for tax positions related to the current year	'	'	'	-6.3	'	-3.3
Reductions for tax positions of prior years	'	'	'	'	'	-28.7
Ending balance, Unrecognized tax benefits	176.4	'	'	176.4	'	108.9
Amount of unrecognized tax benefits that would reduce the effective income tax rate, if recognized	61.6	'	'	61.6	'	'
Accumulated pre-tax interest and penalties related to unrecognized tax benefits	$100	'	'	$100	'	$37

Employee_and_Agent_Benefits_De

Employee and Agent Benefits (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Contributions	'	'	'	'
Minimum annual contribution required in current fiscal year for qualified pension plan	'	'	$0	'
The low end of the range of possible contributions to be made during the current fiscal year to the qualified and nonqualified pension plans combined	125	'	125	'
The high end of the range of possible contributions to be made during the current fiscal year to the qualified and nonqualified pension plans combined	150	'	150	'
Contributions made by employer to fund qualified and nonqualified pension plans	40.3	'	97.8	'
Pension benefits	'	'	'	'
Components of Net Periodic Benefit Cost (Income)	'	'	'	'
Service cost	13.5	14.3	40.5	42.9
Interest cost	29.2	25.9	87.8	77.7
Expected return on plan assets	-33	-31.8	-99	-95.6
Amortization of prior service (benefit) cost	-1	-2.1	-3.4	-6.3
Recognized net actuarial (gain) loss	12.5	29.5	37.8	88.6
Net periodic benefit cost (income)	21.2	35.8	63.7	107.3
Other postretirement benefits	'	'	'	'
Components of Net Periodic Benefit Cost (Income)	'	'	'	'
Service cost	0.4	0.3	1.1	0.9
Interest cost	1.7	1.4	5	4.2
Expected return on plan assets	-8.2	-7.2	-24.5	-21.6
Amortization of prior service (benefit) cost	-5	-6.5	-15.2	-19.5
Recognized net actuarial (gain) loss	-1	0.3	-2.7	0.9
Net periodic benefit cost (income)	($12.10)	($11.70)	($36.30)	($35.10)

Contingencies_Guarantees_and_I1

Contingencies, Guarantees and Indemnifications (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2008	Sep. 30, 2014
Loss contingencies - disclosures	'	'
Proceeds from termination of certain structured transactions and the resulting prepayment	$440	'
Amount, including interest, attempted to be recovered	'	532
Estimated losses accrued related to legal matters	'	0
Maximum exposure under guarantees	'	$254

Stockholders_Equity_Details

Stockholders' Equity (Details ) (USD $)

1 Months Ended

9 Months Ended

In Millions, unless otherwise specified

Feb. 28, 2014

Feb. 28, 2013

31-May-12

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2013

Dec. 31, 2012

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2013

Dec. 31, 2012

Common stock

Common stock

Common stock

Common stock

Common stock

Series A

Series A

Series A

Series A

Series B

Series B

Series B

Series B

Preferred stock

Preferred stock

Preferred stock

Preferred stock

Preferred stock

Preferred stock

Preferred stock

Preferred stock

Reconciliation of Outstanding Shares

'

'

'

'

'

'

'

'

'

'

'

'

'

Outstanding shares at beginning of period

'

'

'

295.2

293.8

3

3

3

3

10

10

10

10

Shares issued

'

'

'

3.1

4.5

'

'

'

'

'

'

'

'

Treasury stock acquired

'

'

'

-4.7

-4.4

'

'

'

'

'

'

'

'

Outstanding shares at end of period

'

'

'

293.6

293.9

3

3

3

3

10

10

10

10

Common stock share repurchase disclosures

'

'

'

'

'

'

'

'

'

'

'

'

'

Share repurchase program, maximum authorized amount (in dollars)

$200

$150

$200

'

'

'

'

'

'

'

'

'

'

Stockholders_Equity_Details_2

Stockholders' Equity (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Comprehensive Income (Loss) Pre-Tax	'	'	'	'
Net unrealized gains (losses) on available-for-sale securities during the period, pre-tax	($301.80)	($40.90)	$1,009.90	($1,578.40)
Reclassification adjustment for (gains) losses on available-for-sale securities included in net income, pre-tax	4.3	8.4	-57.4	66.8
Adjustments for assumed changes in amortization patterns related to available-for-sale securities, pre-tax	28.2	29.3	-71	241.1
Adjustments for assumed changes in policyholder liabilities related to available-for-sale securities, pre-tax	149.8	54.1	-434.7	505.7
Net unrealized gains (losses) on available-for-sale securities, pre-tax	-119.5	50.9	446.8	-764.8
Noncredit component of impairment losses on fixed maturities, available-for-sale during the period, pre-tax	14.7	9.3	82.6	-8.8
Adjustments for assumed changes in amortization patterns related to noncredit component of impairment losses on fixed maturities, available-for-sale, pre-tax	3.1	-13.7	-5.3	-13.6
Adjustments for assumed changes in policyholder liabilities related to noncredit component of impairment losses on fixed maturities, available-for-sale, pre-tax	-0.9	-0.2	-1.5	0.8
Noncredit component of impairment losses on fixed maturities, available-for-sale, pre-tax	16.9	-4.6	75.8	-21.6
Net unrealized gains (losses) on derivative instruments during the period, pre-tax	48.4	-45.7	67.7	-31.7
Reclassification adjustment for (gains) losses on derivative instruments included in net income, pre-tax	-1.8	1.9	6.3	1.6
Adjustments for assumed changes in amortization patterns related to derivative instruments, pre-tax	-8.4	2.6	-8.9	9
Adjustments for assumed changes in policyholder liabilities related to derivative instruments, pre-tax	6.9	2.7	0.4	15.3
Net unrealized gains (losses) on derivative instruments, pre-tax	45.1	-38.5	65.5	-5.8
Foreign currency translation adjustment, pre-tax	-210.3	-32	-231.2	-177.3
Amortization of prior service (benefit) cost and actuarial (gain) loss included in net periodic benefit cost, pre-tax	5.5	21.2	16.5	63.7
Net unrecognized postretirement benefit obligation, pre-tax	5.5	21.2	16.5	63.7
Other comprehensive income (loss), pre-tax	-262.3	-3	373.4	-905.8
Other Comprehensive Income (Loss) Tax	'	'	'	'
Net unrealized gains (losses) on available-for-sale securities during the period, tax	103.8	9.1	-340.7	511.6
Reclassification adjustment for (gains) losses on available-for-sale securities included in net income, tax	-1.4	-2.9	18.8	-22.7
Adjustments for assumed changes in amortization patterns related to available-for-sale securities, tax	-9.8	-10.3	24.9	-84.4
Adjustments for assumed changes in policyholder liabilities related to available-for-sale securities, tax	-47	-17.5	146.8	-163.4
Net unrealized gains (losses) on available-for-sale securities, tax	45.6	-21.6	-150.2	241.1
Noncredit component of impairment losses on fixed maturities, available-for-sale during the period, tax	-5	-2.9	-29.3	3.9
Adjustments for assumed changes in amortization patterns related to noncredit component of impairment losses on fixed maturities, available-for-sale, tax	-1.2	4.9	1.9	4.9
Adjustments for assumed changes in policyholder liabilities related to noncredit component of impairment losses on fixed maturities, available-for-sale, tax	0.3	0.1	0.5	-0.3
Noncredit component of impairment losses on fixed maturities, available-for-sale, tax	-5.9	2.1	-26.9	8.5
Net unrealized gains (losses) on derivative instruments during the period, tax	-17	15.9	-23.8	11.7
Reclassification adjustment for (gains) losses on derivative instruments included in net income, tax	0.6	-0.8	-2.4	-0.8
Adjustments for assumed changes in amortization patterns related to derivative instruments, tax	2.9	-1	3.1	-3.2
Adjustments for assumed changes in policyholder liabilities related to derivative instruments, tax	-2.4	-0.7	-0.1	-5.3
Net unrealized gains (losses) on derivative instruments, tax	-15.9	13.4	-23.2	2.4
Foreign currency translation adjustment, tax	14.5	-1.5	22.8	7.8
Amortization of prior service (benefit) cost and actuarial (gain) loss included in net periodic benefit cost, tax	-1.9	-7.4	-5.8	-22.3
Net unrecognized postretirement benefit obligation, tax	-1.9	-7.4	-5.8	-22.3
Other comprehensive income (loss), tax	36.4	-15	-183.3	237.5
Other Comprehensive Income (Loss) After-Tax	'	'	'	'
Net unrealized gains (losses) on available-for-sale securities during the period	-198	-31.8	669.2	-1,066.80
Reclassification adjustment for (gains) losses on available-for-sale securities included in net income	2.9	5.5	-38.6	44.1
Adjustments for assumed changes in amortization patterns related to available-for-sale securities	18.4	19	-46.1	156.7
Adjustments for assumed changes in policyholder liabilities related to available-for-sale securities	102.8	36.6	-287.9	342.3
Net unrealized gains (losses) on available-for-sale securities	-73.9	29.3	296.6	-523.7
Noncredit component of impairment losses on fixed maturities, available-for-sale during the period	9.7	6.4	53.3	-4.9
Adjustments for assumed changes in amortization patterns related to noncredit component of impairment losses on fixed maturities, available-for-sale	1.9	-8.8	-3.4	-8.7
Adjustments for assumed changes in policyholder liabilities related to noncredit component of impairment losses on fixed maturities, available-for-sale	-0.6	-0.1	-1	0.5
Noncredit component of impairment losses on fixed maturities, available-for-sale	11	-2.5	48.9	-13.1
Net unrealized gains (losses) on derivative instruments during the period	31.4	-29.8	43.9	-20
Reclassification adjustment for (gains) losses on derivative instruments included in net income	-1.2	1.1	3.9	0.8
Adjustments for assumed changes in amortization patterns related to derivative instruments	-5.5	1.6	-5.8	5.8
Adjustments for assumed changes in policyholder liabilities related to derivative instruments	4.5	2	0.3	10
Net unrealized gains (losses) on derivative instruments	29.2	-25.1	42.3	-3.4
Foreign currency translation adjustment	-195.8	-33.5	-208.4	-169.5
Amortization of prior service (benefit) cost and actuarial (gain) loss included in net periodic benefit cost	3.6	13.8	10.7	41.4
Net unrecognized postretirement benefit obligation	3.6	13.8	10.7	41.4
Other comprehensive income (loss)	($225.90)	($18)	$190.10	($668.30)

Stockholders_Equity_Details_3

Stockholders' Equity (Details 3) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Change in accumulated other comprehensive income (loss) rollforward	'	'
Accumulated other comprehensive income (loss), balance at beginning of period	$183.20	'
Accumulated other comprehensive income (loss), balance at end of period	380.1	'
Change in redeemable noncontrolling interest rollforward	'	'
Redeemable noncontrolling interest, balance at beginning of period	247.2	60.4
Net income (loss) attributable to redeemable noncontrolling interest	8.3	9
Reclassification from stockholders' equity	'	173.9
Redeemable noncontrolling interest assumed related to acquisition	'	1.2
Contributions from redeemable noncontrolling interest	0.1	'
Distributions to redeemable noncontrolling interest	-14.4	-9.9
Purchase of subsidiary shares from redeemable noncontrolling interest	-216.8	-2.4
Change in redemption value of redeemable noncontrolling interest	33.2	5.6
Foreign currency translation adjustment, redeemable noncontrolling interest	-1.5	-3.3
Redeemable noncontrolling interest, balance at end of period	56.1	234.5
Net unrealized gains (losses) on available-for-sale securities	'	'
Change in accumulated other comprehensive income (loss) rollforward	'	'
Accumulated other comprehensive income (loss), balance at beginning of period	878.1	1,418.30
Other comprehensive income (loss) during the period, net of adjustments	335.2	-567.8
Amounts reclassified from accumulated other comprehensive income (loss)	-38.6	44.1
Other comprehensive income (loss) attributable to Principal Financial Group, Inc.	296.6	-523.7
Accumulated other comprehensive income (loss), balance at end of period	1,174.70	894.6
Noncredit component of impairment losses on fixed maturities available-for-sale	'	'
Change in accumulated other comprehensive income (loss) rollforward	'	'
Accumulated other comprehensive income (loss), balance at beginning of period	-167	-173.9
Other comprehensive income (loss) during the period, net of adjustments	'	-13.1
Amounts reclassified from accumulated other comprehensive income (loss)	48.9	'
Other comprehensive income (loss) attributable to Principal Financial Group, Inc.	48.9	-13.1
Accumulated other comprehensive income (loss), balance at end of period	-118.1	-187
Net unrealized gains (losses) on derivative instruments	'	'
Change in accumulated other comprehensive income (loss) rollforward	'	'
Accumulated other comprehensive income (loss), balance at beginning of period	-10.5	-8.7
Other comprehensive income (loss) during the period, net of adjustments	38.4	-4.2
Amounts reclassified from accumulated other comprehensive income (loss)	3.9	0.8
Other comprehensive income (loss) attributable to Principal Financial Group, Inc.	42.3	-3.4
Accumulated other comprehensive income (loss), balance at end of period	31.8	-12.1
Foreign currency translation adjustment	'	'
Change in accumulated other comprehensive income (loss) rollforward	'	'
Accumulated other comprehensive income (loss), balance at beginning of period	-361.5	-106.9
Other comprehensive income (loss) during the period, net of adjustments	-201.6	-159.2
Other comprehensive income (loss) attributable to Principal Financial Group, Inc.	-201.6	-159.2
Accumulated other comprehensive income (loss), balance at end of period	-563.1	-266.1
Unrecognized postretirement benefit obligations	'	'
Change in accumulated other comprehensive income (loss) rollforward	'	'
Accumulated other comprehensive income (loss), balance at beginning of period	-155.9	-488.5
Amounts reclassified from accumulated other comprehensive income (loss)	10.7	41.4
Other comprehensive income (loss) attributable to Principal Financial Group, Inc.	10.7	41.4
Accumulated other comprehensive income (loss), balance at end of period	-145.2	-447.1
Accumulated other comprehensive income (loss)	'	'
Change in accumulated other comprehensive income (loss) rollforward	'	'
Accumulated other comprehensive income (loss), balance at beginning of period	183.2	640.3
Other comprehensive income (loss) during the period, net of adjustments	172	-744.3
Amounts reclassified from accumulated other comprehensive income (loss)	24.9	86.3
Other comprehensive income (loss) attributable to Principal Financial Group, Inc.	196.9	-658
Accumulated other comprehensive income (loss), balance at end of period	$380.10	($17.70)

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets (liabilities) measured at fair value on a recurring basis	'	'
Derivative assets	$558.70	$665.10
Separate account assets	138,296.70	130,018.40
Investment-type insurance contracts	-94.1	-6.9
Fixed maturities valued using internal pricing models	'	'
Fixed maturities classified as Level 3 assets, percent valued using internal pricing models (as a percent)	1.00%	'
Fixed maturities	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	49,627.50	48,757.10
U.S. government and agencies	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	892.1	780.5
Non-U.S. governments	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	904.7	996.8
States and political subdivisions	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	4,094	3,658
Corporate debt securities	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	32,020.20	31,919
Residential mortgage-backed pass-through securities	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	2,809	2,845.20
Commercial mortgage-backed securities	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	4,012.30	4,026.40
Collateralized debt obligations	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	480.8	363.4
Other debt obligations	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	4,414.40	4,167.80
Equity securities	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	124.8	110.5
Recurring Fair Value Measurements | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Derivative assets	558.7	665.1
Other investments	420.6	361.1
Cash equivalents	473.2	1,459
Sub-total excluding separate account assets	52,621.80	52,632.80
Separate account assets	138,296.70	130,018.40
Total assets	190,918.50	182,651.20
Investment-type insurance contracts	-94.1	-6.9
Derivative liabilities	-794.6	-1,024.60
Other liabilities	-307.8	-322.1
Total liabilities	-1,196.50	-1,353.60
Net assets (liabilities)	189,722	181,297.60
Recurring Fair Value Measurements | Fair value hierarchy Level 1	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Other investments	3.3	6.8
Sub-total excluding separate account assets	710.3	599.6
Separate account assets	71,356.30	67,215.10
Total assets	72,066.60	67,814.70
Net assets (liabilities)	72,066.60	67,814.70
Recurring Fair Value Measurements | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Derivative assets	501	590.9
Other investments	293	211.4
Cash equivalents	473.2	1,459
Sub-total excluding separate account assets	51,194.90	51,292.50
Separate account assets	61,163	57,538.10
Total assets	112,357.90	108,830.60
Derivative liabilities	-756.8	-985
Other liabilities	-246.8	-248.2
Total liabilities	-1,003.60	-1,233.20
Net assets (liabilities)	111,354.30	107,597.40
Recurring Fair Value Measurements | Fair value hierarchy Level 3	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Derivative assets	57.7	74.2
Other investments	124.3	142.9
Sub-total excluding separate account assets	716.6	740.7
Separate account assets	5,777.40	5,265.20
Total assets	6,494	6,005.90
Investment-type insurance contracts	-94.1	-6.9
Derivative liabilities	-37.8	-39.6
Other liabilities	-61	-73.9
Total liabilities	-192.9	-120.4
Net assets (liabilities)	6,301.10	5,885.50
Recurring Fair Value Measurements | Fixed maturities | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	49,627.50	48,757.10
Trading	609.4	563.1
Recurring Fair Value Measurements | Fixed maturities | Fair value hierarchy Level 1	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	559.3	449.6
Trading	4.9	'
Recurring Fair Value Measurements | Fixed maturities | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	48,690.30	47,970.70
Trading	465.2	393.2
Recurring Fair Value Measurements | Fixed maturities | Fair value hierarchy Level 3	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	377.9	336.8
Trading	139.3	169.9
Recurring Fair Value Measurements | U.S. government and agencies | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	892.1	780.5
Recurring Fair Value Measurements | U.S. government and agencies | Fair value hierarchy Level 1	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	519	409.3
Recurring Fair Value Measurements | U.S. government and agencies | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	373.1	371.2
Recurring Fair Value Measurements | Non-U.S. governments | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	904.7	996.8
Recurring Fair Value Measurements | Non-U.S. governments | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	863.4	949.3
Recurring Fair Value Measurements | Non-U.S. governments | Fair value hierarchy Level 3	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	41.3	47.5
Recurring Fair Value Measurements | States and political subdivisions | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	4,094	3,658
Recurring Fair Value Measurements | States and political subdivisions | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	4,092.30	3,656.20
Recurring Fair Value Measurements | States and political subdivisions | Fair value hierarchy Level 3	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	1.7	1.8
Recurring Fair Value Measurements | Corporate debt securities | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	32,020.20	31,919
Recurring Fair Value Measurements | Corporate debt securities | Fair value hierarchy Level 1	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	40.3	40.3
Recurring Fair Value Measurements | Corporate debt securities | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	31,757.70	31,714.70
Recurring Fair Value Measurements | Corporate debt securities | Fair value hierarchy Level 3	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	222.2	164
Recurring Fair Value Measurements | Residential mortgage-backed pass-through securities | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	2,809	2,845.20
Recurring Fair Value Measurements | Residential mortgage-backed pass-through securities | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	2,809	2,845.20
Recurring Fair Value Measurements | Commercial mortgage-backed securities | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	4,012.30	4,026.40
Recurring Fair Value Measurements | Commercial mortgage-backed securities | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	4,006.90	4,024.80
Recurring Fair Value Measurements | Commercial mortgage-backed securities | Fair value hierarchy Level 3	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	5.4	1.6
Recurring Fair Value Measurements | Collateralized debt obligations | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	480.8	363.4
Recurring Fair Value Measurements | Collateralized debt obligations | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	419.2	325.6
Recurring Fair Value Measurements | Collateralized debt obligations | Fair value hierarchy Level 3	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	61.6	37.8
Recurring Fair Value Measurements | Other debt obligations | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	4,414.40	4,167.80
Recurring Fair Value Measurements | Other debt obligations | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	4,368.70	4,083.70
Recurring Fair Value Measurements | Other debt obligations | Fair value hierarchy Level 3	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	45.7	84.1
Recurring Fair Value Measurements | Equity securities | Assets (liabilities) measured at fair value	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	124.8	110.5
Trading	807.6	716.9
Recurring Fair Value Measurements | Equity securities | Fair value hierarchy Level 1	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	40.3	38.1
Trading	102.5	105.1
Recurring Fair Value Measurements | Equity securities | Fair value hierarchy Level 2	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	67.1	55.5
Trading	705.1	611.8
Recurring Fair Value Measurements | Equity securities | Fair value hierarchy Level 3	'	'
Assets (liabilities) measured at fair value on a recurring basis	'	'
Available-for-sale	$17.40	$16.90

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (Recurring Fair Value Measurements, USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Available-for-sale | Fixed maturities	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	$333.60	$273.60	$336.80	$313
Total realized/unrealized gains (losses) included in net income, assets	-2.4	-0.4	-3.3	-3.2
Total realized/unrealized gains (losses) included in other comprehensive income, assets	-2.7	3	1.9	2.6
Net purchases, sales, issuances and settlements, assets	50.9	34.1	51.4	-64.3
Transfers into Level 3, assets	16.4	19.7	53.4	154.2
Transfers out of Level 3, assets	-17.9	-32.1	-62.3	-104.4
Ending balance, assets	377.9	297.9	377.9	297.9
Changes in unrealized gains (losses) included in net income relating to positions still held, assets	-2.3	-0.4	-3.1	-2.4
Gross purchases, sales, issuances and settlements	'	'	'	'
Purchases, assets	58.4	36.9	131.6	70.8
Sales, assets	-5.5	-0.7	-50	-83.7
Settlements, assets	-2	-2.1	-30.2	-51.4
Net purchases, sales, issuances and settlements, assets	50.9	34.1	51.4	-64.3
Available-for-sale | Non-U.S. governments	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	39.6	44.7	47.5	44.3
Total realized/unrealized gains (losses) included in net income, assets	'	'	-0.1	-0.1
Total realized/unrealized gains (losses) included in other comprehensive income, assets	-0.2	-0.3	-0.2	-0.8
Net purchases, sales, issuances and settlements, assets	1.9	3.4	-5.9	4.4
Ending balance, assets	41.3	47.8	41.3	47.8
Changes in unrealized gains (losses) included in net income relating to positions still held, assets	'	'	-0.1	-0.1
Gross purchases, sales, issuances and settlements	'	'	'	'
Purchases, assets	2.2	3.7	5.8	9.2
Sales, assets	'	'	-10.8	-3.9
Settlements, assets	-0.3	-0.3	-0.9	-0.9
Net purchases, sales, issuances and settlements, assets	1.9	3.4	-5.9	4.4
Available-for-sale | States and political subdivisions	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	1.7	1.7	1.8	1.9
Total realized/unrealized gains (losses) included in other comprehensive income, assets	0	0.1	'	'
Net purchases, sales, issuances and settlements, assets	'	'	-0.1	-0.1
Ending balance, assets	1.7	1.8	1.7	1.8
Gross purchases, sales, issuances and settlements	'	'	'	'
Settlements, assets	'	'	-0.1	-0.1
Net purchases, sales, issuances and settlements, assets	'	'	-0.1	-0.1
Available-for-sale | Corporate debt securities	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	170	168.1	164	174.5
Total realized/unrealized gains (losses) included in net income, assets	-1.4	-0.1	-1.6	-4.9
Total realized/unrealized gains (losses) included in other comprehensive income, assets	-2.8	2.7	-1.7	-7
Net purchases, sales, issuances and settlements, assets	40.7	17.1	21	-25.3
Transfers into Level 3, assets	15.7	4.7	46.6	105.3
Transfers out of Level 3, assets	'	-29.5	-6.1	-79.6
Ending balance, assets	222.2	163	222.2	163
Changes in unrealized gains (losses) included in net income relating to positions still held, assets	-1.4	-0.1	-1.5	-2
Gross purchases, sales, issuances and settlements	'	'	'	'
Purchases, assets	46.5	18.2	64.5	29.6
Sales, assets	-5.5	-0.7	-39.2	-32.4
Settlements, assets	-0.3	-0.4	-4.3	-22.5
Net purchases, sales, issuances and settlements, assets	40.7	17.1	21	-25.3
Available-for-sale | Commercial mortgage-backed securities	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	6.7	'	1.6	'
Total realized/unrealized gains (losses) included in net income, assets	-1	'	-1.6	'
Total realized/unrealized gains (losses) included in other comprehensive income, assets	0.2	'	1.3	'
Net purchases, sales, issuances and settlements, assets	0.2	'	-0.2	'
Transfers into Level 3, assets	0.7	'	6.8	'
Transfers out of Level 3, assets	-1.4	'	-2.5	'
Ending balance, assets	5.4	'	5.4	'
Changes in unrealized gains (losses) included in net income relating to positions still held, assets	-0.9	'	-1.5	'
Gross purchases, sales, issuances and settlements	'	'	'	'
Settlements, assets	0.2	'	-0.2	'
Net purchases, sales, issuances and settlements, assets	0.2	'	-0.2	'
Available-for-sale | Collateralized debt obligations	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	68.5	40.7	37.8	77.6
Total realized/unrealized gains (losses) included in net income, assets	'	'	'	2.1
Total realized/unrealized gains (losses) included in other comprehensive income, assets	0.1	-0.1	1.4	7.4
Net purchases, sales, issuances and settlements, assets	9.5	'	46.4	-56
Transfers into Level 3, assets	'	'	'	31.7
Transfers out of Level 3, assets	-16.5	-2.6	-24	-24.8
Ending balance, assets	61.6	38	61.6	38
Gross purchases, sales, issuances and settlements	'	'	'	'
Purchases, assets	9.7	'	61.3	17
Sales, assets	'	'	'	-47.4
Settlements, assets	-0.2	'	-14.9	-25.6
Net purchases, sales, issuances and settlements, assets	9.5	'	46.4	-56
Available-for-sale | Other debt obligations	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	47.1	18.4	84.1	14.7
Total realized/unrealized gains (losses) included in net income, assets	'	-0.3	'	-0.3
Total realized/unrealized gains (losses) included in other comprehensive income, assets	'	0.6	1.1	3
Net purchases, sales, issuances and settlements, assets	-1.4	13.6	-9.8	12.7
Transfers into Level 3, assets	'	15	'	17.2
Transfers out of Level 3, assets	'	'	-29.7	'
Ending balance, assets	45.7	47.3	45.7	47.3
Changes in unrealized gains (losses) included in net income relating to positions still held, assets	'	-0.3	'	-0.3
Gross purchases, sales, issuances and settlements	'	'	'	'
Purchases, assets	'	15	'	15
Settlements, assets	-1.4	-1.4	-9.8	-2.3
Net purchases, sales, issuances and settlements, assets	-1.4	13.6	-9.8	12.7
Available-for-sale | Equity securities	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	17.5	16.9	16.9	15.3
Total realized/unrealized gains (losses) included in net income, assets	-0.3	'	-0.3	'
Total realized/unrealized gains (losses) included in other comprehensive income, assets	0.2	0.3	0.6	1.9
Transfers into Level 3, assets	'	'	0.2	'
Ending balance, assets	17.4	17.2	17.4	17.2
Changes in unrealized gains (losses) included in net income relating to positions still held, assets	-0.3	'	-0.3	'
Trading | Fixed maturities	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	159.6	170.7	169.9	166.8
Total realized/unrealized gains (losses) included in net income, assets	3.7	2.1	9.5	6
Net purchases, sales, issuances and settlements, assets	-24	0.1	-40.1	0.1
Ending balance, assets	139.3	172.9	139.3	172.9
Changes in unrealized gains (losses) included in net income relating to positions still held, assets	0.2	2.1	0.8	6.1
Gross purchases, sales, issuances and settlements	'	'	'	'
Sales, assets	-10	'	-10	'
Settlements, assets	-14	0.1	-30.1	0.1
Net purchases, sales, issuances and settlements, assets	-24	0.1	-40.1	0.1
Derivative assets	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	62.3	56.9	74.2	75.1
Total realized/unrealized gains (losses) included in net income, assets	-14.4	1	-26.4	-21.3
Net purchases, sales, issuances and settlements, assets	9.8	-0.4	9.9	3.7
Ending balance, assets	57.7	57.5	57.7	57.5
Changes in unrealized gains (losses) included in net income relating to positions still held, assets	-14.3	1.2	-26.4	-21.6
Gross purchases, sales, issuances and settlements	'	'	'	'
Purchases, assets	9.8	'	9.9	7.2
Sales, assets	'	-0.4	'	-3.5
Net purchases, sales, issuances and settlements, assets	9.8	-0.4	9.9	3.7
Other investments	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	134.6	116.5	142.9	113.9
Total realized/unrealized gains (losses) included in net income, assets	3.8	1.8	6.6	7.1
Net purchases, sales, issuances and settlements, assets	-14.1	22.2	-25.2	19.5
Ending balance, assets	124.3	140.5	124.3	140.5
Changes in unrealized gains (losses) included in net income relating to positions still held, assets	3.8	1.9	6.6	7.1
Gross purchases, sales, issuances and settlements	'	'	'	'
Purchases, assets	'	25.7	0.2	28.3
Settlements, assets	-14.1	-3.5	-25.4	-8.8
Net purchases, sales, issuances and settlements, assets	-14.1	22.2	-25.2	19.5
Separate account assets	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, assets	5,533.60	4,841.70	5,265.20	4,616
Total realized/unrealized gains (losses) included in net income, assets	167	134.6	358.4	427.2
Total realized/unrealized gains (losses) included in other comprehensive income, assets	-0.3	0.1	-0.2	'
Net purchases, sales, issuances and settlements, assets	79	-33.7	161.3	-108.1
Transfers into Level 3, assets	2.3	4.9	4.4	12.7
Transfers out of Level 3, assets	-4.2	-6.3	-11.7	-6.5
Ending balance, assets	5,777.40	4,941.30	5,777.40	4,941.30
Changes in unrealized gains (losses) included in net income relating to positions still held, assets	163.7	122	359.9	406.3
Gross purchases, sales, issuances and settlements	'	'	'	'
Purchases, assets	228.5	33.6	467.2	143.2
Sales, assets	-127.3	-54.7	-257.5	-223.4
Issuances, assets	-196.5	-1.4	-290.1	-7.6
Settlements, assets	174.3	-11.2	241.7	-20.3
Net purchases, sales, issuances and settlements, assets	79	-33.7	161.3	-108.1
Investment-type insurance contracts	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, liabilities	-37.6	-74.2	-6.9	-170.5
Total realized/unrealized gains (losses) included in net income, liabilities	-62.8	17.6	-109.9	111.2
Net purchases, sales, issuances and settlements, liabilities	6.3	7.3	22.7	10
Ending balance, liabilities	-94.1	-49.3	-94.1	-49.3
Changes in unrealized gains (losses) included in net income relating to positions still held, liabilities	-56.1	19.8	-109.9	109.2
Gross purchases, sales, issuances and settlements	'	'	'	'
Issuances, liabilities	4.2	5.4	18.7	5.6
Settlements, liabilities	2.1	1.9	4	4.4
Net purchases, sales, issuances and settlements, liabilities	6.3	7.3	22.7	10
Derivative liabilities	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, liabilities	-24.7	-70	-39.6	-102.6
Total realized/unrealized gains (losses) included in net income, liabilities	-13.3	14.1	0.5	44.4
Total realized/unrealized gains (losses) included in other comprehensive income, liabilities	-0.6	0.3	0.7	-0.2
Net purchases, sales, issuances and settlements, liabilities	0.8	5.6	0.6	8.4
Ending balance, liabilities	-37.8	-50	-37.8	-50
Changes in unrealized gains (losses) included in net income relating to positions still held, liabilities	-14.5	14.2	-3.7	43.8
Gross purchases, sales, issuances and settlements	'	'	'	'
Purchases, liabilities	-0.6	'	-0.8	-3.1
Sales, liabilities	1.4	5.6	1.4	11.5
Net purchases, sales, issuances and settlements, liabilities	0.8	5.6	0.6	8.4
Other liabilities	'	'	'	'
Changes in Level 3 fair value measurements rollforward, assets and liabilities	'	'	'	'
Beginning balance, liabilities	-79.9	-59.6	-73.9	-39.6
Total realized/unrealized gains (losses) included in net income, liabilities	9.9	-7.5	3.9	-27.5
Net purchases, sales, issuances and settlements, liabilities	9	'	9	'
Ending balance, liabilities	-61	-67.1	-61	-67.1
Changes in unrealized gains (losses) included in net income relating to positions still held, liabilities	9.8	-7.6	4.5	-27.5
Gross purchases, sales, issuances and settlements	'	'	'	'
Sales, liabilities	9	'	9	'
Net purchases, sales, issuances and settlements, liabilities	$9	'	$9	'

Fair_Value_Measurements_Detail2

Fair Value Measurements (Details 3) (Recurring Fair Value Measurements, USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Available-for-sale | Fixed maturities	'	'	'	'
Fair Value Hierarchy Levels Transfers	'	'	'	'
Transfers out of Level 2 into Level 3	$16.40	$19.70	$53.40	$154.20
Transfers out of Level 3 into Level 2	17.9	32.1	62.3	104.4
Available-for-sale | Corporate debt securities	'	'	'	'
Fair Value Hierarchy Levels Transfers	'	'	'	'
Transfers out of Level 2 into Level 3	15.7	4.7	46.6	105.3
Transfers out of Level 3 into Level 2	'	29.5	6.1	79.6
Available-for-sale | Collateralized debt obligations	'	'	'	'
Fair Value Hierarchy Levels Transfers	'	'	'	'
Transfers out of Level 2 into Level 3	'	'	'	31.7
Transfers out of Level 3 into Level 2	16.5	2.6	24	24.8
Available-for-sale | Other debt obligations	'	'	'	'
Fair Value Hierarchy Levels Transfers	'	'	'	'
Transfers out of Level 2 into Level 3	'	15	'	17.2
Transfers out of Level 3 into Level 2	'	'	29.7	'
Available-for-sale | Commercial mortgage-backed securities	'	'	'	'
Fair Value Hierarchy Levels Transfers	'	'	'	'
Transfers out of Level 2 into Level 3	0.7	'	6.8	'
Transfers out of Level 3 into Level 2	1.4	'	2.5	'
Available-for-sale | Equity securities	'	'	'	'
Fair Value Hierarchy Levels Transfers	'	'	'	'
Transfers out of Level 2 into Level 3	'	'	0.2	'
Separate account assets	'	'	'	'
Fair Value Hierarchy Levels Transfers	'	'	'	'
Transfers out of Level 1 into Level 2	2.1	7.1	17.5	250.9
Transfers out of Level 1 into Level 3	'	'	'	0.1
Transfers out of Level 2 into Level 1	17.5	6.9	71.3	11.7
Transfers out of Level 2 into Level 3	2.3	4.9	4.4	12.6
Transfers out of Level 3 into Level 2	$4.20	$6.30	$11.70	$6.50

Fair_Value_Measurements_Detail3

Fair Value Measurements (Details 4) (Recurring Fair Value Measurements, USD $)	9 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets (liabilities) measured at fair value	'	'
Unobservable inputs	'	'
Assets measured at fair value	190,918.50	182,651.20
Liabilities measured at fair value	-1,196.50	-1,353.60
Assets (liabilities) measured at fair value | Available-for-sale | Non-U.S. governments	'	'
Unobservable inputs	'	'
Assets measured at fair value	10.7	11.7
Assets (liabilities) measured at fair value | Available-for-sale | Corporate debt securities	'	'
Unobservable inputs	'	'
Assets measured at fair value	71.7	70.1
Assets (liabilities) measured at fair value | Available-for-sale | Commercial mortgage-backed securities	'	'
Unobservable inputs	'	'
Assets measured at fair value	5	1.6
Assets (liabilities) measured at fair value | Available-for-sale | Collateralized debt obligations	'	'
Unobservable inputs	'	'
Assets measured at fair value	9.7	13.6
Assets (liabilities) measured at fair value | Available-for-sale | Other debt obligations	'	'
Unobservable inputs	'	'
Assets measured at fair value	31.2	33.6
Assets (liabilities) measured at fair value | Trading | Fixed maturities	'	'
Unobservable inputs	'	'
Assets measured at fair value	15.1	36.2
Assets (liabilities) measured at fair value | Trading | Collateralized private investment vehicle | Fixed maturities	'	'
Unobservable inputs	'	'
Assets measured at fair value	100.4	110.4
Assets (liabilities) measured at fair value | Other investments | Discounted cash flow, commercial mortgage loans of consolidated VIEs	'	'
Unobservable inputs	'	'
Assets measured at fair value	41.9	68.1
Assets (liabilities) measured at fair value | Other investments | Discounted cash flow, equity method real estate investment	'	'
Unobservable inputs	'	'
Assets measured at fair value	82.4	74.8
Assets (liabilities) measured at fair value | Separate account assets	'	'
Unobservable inputs	'	'
Assets measured at fair value	5,605.60	5,090.40
Assets (liabilities) measured at fair value | Investment-type insurance contracts	'	'
Unobservable inputs	'	'
Liabilities measured at fair value	-94.1	-6.9
Assets (liabilities) measured at fair value | Derivative liabilities	'	'
Unobservable inputs	'	'
Liabilities measured at fair value	-11.9	-19.9
Assets (liabilities) measured at fair value | Other liabilities	'	'
Unobservable inputs	'	'
Liabilities measured at fair value	-61	-73.9
Fair value hierarchy Level 3	'	'
Unobservable inputs	'	'
Assets measured at fair value	6,494	6,005.90
Liabilities measured at fair value	-192.9	-120.4
Fair value hierarchy Level 3 | Available-for-sale | Non-U.S. governments | Discounted cash flow | Input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	2.00%	2.00%
Illiquidity premium (as a percent)	0.50%	0.50%
Fair value hierarchy Level 3 | Available-for-sale | Non-U.S. governments | Discounted cash flow | Weighted average input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	2.00%	2.00%
Illiquidity premium (as a percent)	0.50%	0.50%
Fair value hierarchy Level 3 | Available-for-sale | Corporate debt securities | Discounted cash flow | Minimum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	1.80%	1.90%
Illiquidity premium (as a percent)	0.00%	0.00%
Earnings before interest, taxes, depreciation and amortization multiple	'	0
Comparability adjustment (as a percent)	0.00%	0.00%
Probability of default (as a percent)	'	0.00%
Potential loss severity (as a percent)	'	0.00%
Fair value hierarchy Level 3 | Available-for-sale | Corporate debt securities | Discounted cash flow | Maximum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	7.50%	7.70%
Illiquidity premium (as a percent)	0.50%	0.25%
Earnings before interest, taxes, depreciation and amortization multiple	'	4.5
Comparability adjustment (as a percent)	0.04%	1.25%
Probability of default (as a percent)	'	100.00%
Potential loss severity (as a percent)	'	16.00%
Fair value hierarchy Level 3 | Available-for-sale | Corporate debt securities | Discounted cash flow | Weighted average input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	4.20%	4.40%
Illiquidity premium (as a percent)	0.16%	0.15%
Earnings before interest, taxes, depreciation and amortization multiple	'	0.2
Comparability adjustment (as a percent)	0.00%	0.43%
Probability of default (as a percent)	'	5.40%
Potential loss severity (as a percent)	'	0.90%
Fair value hierarchy Level 3 | Available-for-sale | Commercial mortgage-backed securities | Discounted cash flow | Minimum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	4.00%	1.50%
Fair value hierarchy Level 3 | Available-for-sale | Commercial mortgage-backed securities | Discounted cash flow | Maximum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	17.60%	4.50%
Fair value hierarchy Level 3 | Available-for-sale | Commercial mortgage-backed securities | Discounted cash flow | Weighted average input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	17.60%	1.50%
Fair value hierarchy Level 3 | Available-for-sale | Collateralized debt obligations | Discounted cash flow | Input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	2.60%	1.50%
Illiquidity premium (as a percent)	'	4.00%
Fair value hierarchy Level 3 | Available-for-sale | Collateralized debt obligations | Discounted cash flow | Weighted average input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	2.60%	1.50%
Illiquidity premium (as a percent)	'	4.00%
Fair value hierarchy Level 3 | Available-for-sale | Other debt obligations | Discounted cash flow | Minimum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	1.40%	2.00%
Illiquidity premium (as a percent)	0.50%	0.00%
Fair value hierarchy Level 3 | Available-for-sale | Other debt obligations | Discounted cash flow | Maximum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	5.00%	15.00%
Illiquidity premium (as a percent)	10.00%	0.50%
Fair value hierarchy Level 3 | Available-for-sale | Other debt obligations | Discounted cash flow | Weighted average input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	2.30%	6.70%
Illiquidity premium (as a percent)	2.83%	0.11%
Fair value hierarchy Level 3 | Trading | Fixed maturities | Discounted cash flow | Minimum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	1.70%	1.60%
Illiquidity premium (as a percent)	2.00%	0.00%
Fair value hierarchy Level 3 | Trading | Fixed maturities | Discounted cash flow | Maximum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	124.10%	83.00%
Illiquidity premium (as a percent)	14.00%	14.00%
Fair value hierarchy Level 3 | Trading | Fixed maturities | Discounted cash flow | Weighted average input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	3.30%	3.40%
Illiquidity premium (as a percent)	4.50%	3.70%
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, commercial mortgage loans of consolidated VIEs | Input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	4.20%	4.80%
Illiquidity premium (as a percent)	0.70%	0.94%
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, commercial mortgage loans of consolidated VIEs | Weighted average input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	4.20%	4.80%
Illiquidity premium (as a percent)	0.70%	0.94%
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, equity method real estate investment | Minimum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	7.50%	7.80%
Terminal capitalization rate (as a percent)	5.50%	5.50%
Average market rent growth rate (as a percent)	3.40%	3.50%
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, equity method real estate investment | Maximum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	8.10%	8.10%
Terminal capitalization rate (as a percent)	6.80%	6.80%
Average market rent growth rate (as a percent)	3.90%	3.60%
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, equity method real estate investment | Weighted average input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	7.80%	7.90%
Terminal capitalization rate (as a percent)	6.10%	6.10%
Average market rent growth rate (as a percent)	3.60%	3.60%
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, equity method real estate investment debt | Minimum	'	'
Unobservable inputs	'	'
Loan to value (as a percent)	37.90%	40.50%
Credit spread rate (as a percent)	1.80%	1.50%
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, equity method real estate investment debt | Maximum	'	'
Unobservable inputs	'	'
Loan to value (as a percent)	60.30%	61.00%
Credit spread rate (as a percent)	2.00%	2.00%
Fair value hierarchy Level 3 | Other investments | Discounted cash flow, equity method real estate investment debt | Weighted average input	'	'
Unobservable inputs	'	'
Loan to value (as a percent)	49.10%	50.70%
Credit spread rate (as a percent)	1.90%	1.80%
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, mortgage loans | Minimum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	1.00%	0.60%
Illiquidity premium (as a percent)	0.00%	0.00%
Credit spread rate (as a percent)	0.62%	0.32%
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, mortgage loans | Maximum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	6.10%	5.60%
Illiquidity premium (as a percent)	0.60%	0.60%
Credit spread rate (as a percent)	5.56%	4.40%
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, mortgage loans | Weighted average input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	3.10%	3.30%
Illiquidity premium (as a percent)	0.07%	0.12%
Credit spread rate (as a percent)	2.03%	2.14%
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Minimum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	6.00%	6.00%
Terminal capitalization rate (as a percent)	4.50%	4.50%
Average market rent growth rate (as a percent)	1.40%	2.40%
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Maximum	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	22.80%	16.00%
Terminal capitalization rate (as a percent)	9.50%	9.00%
Average market rent growth rate (as a percent)	5.00%	4.70%
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate | Weighted average input	'	'
Unobservable inputs	'	'
Discount rate (as a percent)	7.50%	7.60%
Terminal capitalization rate (as a percent)	6.40%	6.60%
Average market rent growth rate (as a percent)	3.10%	3.00%
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Minimum	'	'
Unobservable inputs	'	'
Loan to value (as a percent)	8.50%	11.00%
Credit spread rate (as a percent)	1.10%	1.50%
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Maximum	'	'
Unobservable inputs	'	'
Loan to value (as a percent)	65.30%	55.90%
Credit spread rate (as a percent)	4.70%	5.20%
Fair value hierarchy Level 3 | Separate account assets | Discounted cash flow, real estate debt | Weighted average input	'	'
Unobservable inputs	'	'
Loan to value (as a percent)	47.80%	50.30%
Credit spread rate (as a percent)	2.40%	3.30%
Fair value hierarchy Level 3 | Investment-type insurance contracts | Discounted cash flow | Minimum	'	'
Unobservable inputs	'	'
Long duration interest rate (as a percent)	3.10%	3.80%
Long-term equity market volatility (as a percent)	14.90%	15.00%
Non-performance risk (as a percent)	0.10%	0.20%
Lapse rate (as a percent)	0.50%	0.50%
Period of swap rate used for calculating long duration interest rate	'20 years	'20 years
Fair value hierarchy Level 3 | Investment-type insurance contracts | Discounted cash flow | Maximum	'	'
Unobservable inputs	'	'
Long duration interest rate (as a percent)	3.20%	3.90%
Long-term equity market volatility (as a percent)	38.40%	40.10%
Non-performance risk (as a percent)	1.20%	1.20%
Lapse rate (as a percent)	14.60%	14.60%
Period of swap rate used for calculating long duration interest rate	'30 years	'30 years

Fair_Value_Measurements_Detail4

Fair Value Measurements (Details 5) (Nonrecurring Fair Value Measurements, Fair value hierarchy Level 3, USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Mortgage loans	'	'	'	'
Assets and liabilities measured at fair value on a nonrecurring basis	'	'	'	'
Fair value of assets measured on nonrecurring basis	$63.80	$101.60	$63.80	$101.60
Net (gain) loss due to change in fair value of assets measured on nonrecurring basis	9.7	4.6	9.1	22.3
Mortgage loans | Minimum	'	'	'	'
Assets and liabilities measured at fair value on a nonrecurring basis	'	'	'	'
Discount rate (as a percent)	'	'	8.80%	8.00%
Terminal capitalization rate (as a percent)	'	'	7.30%	7.50%
Average market rent growth rate (as a percent)	'	'	2.50%	1.00%
Mortgage loans | Maximum	'	'	'	'
Assets and liabilities measured at fair value on a nonrecurring basis	'	'	'	'
Discount rate (as a percent)	'	'	11.00%	20.00%
Terminal capitalization rate (as a percent)	'	'	9.00%	10.50%
Average market rent growth rate (as a percent)	'	'	10.90%	10.90%
Mortgage servicing rights	'	'	'	'
Assets and liabilities measured at fair value on a nonrecurring basis	'	'	'	'
Fair value of assets measured on nonrecurring basis	'	7.6	'	7.6
Net (gain) loss due to change in fair value of assets measured on nonrecurring basis	'	$0	'	($1.30)
Mortgage servicing rights | Input	'	'	'	'
Assets and liabilities measured at fair value on a nonrecurring basis	'	'	'	'
Discount rate (as a percent)	'	'	'	3.90%

Fair_Value_Measurements_Detail5

Fair Value Measurements (Details 6) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
	item	item	item	item
Commercial Mortgage Loans of Consolidated VIEs	'	'	'	'	'
Fair Value Option, Quantitative Disclosures	'	'	'	'	'
Fair value of assets for which fair value option was elected	$41.80	'	$41.80	'	$68.10
Contractual principal amounts of assets for which the fair value option was elected	38.5	'	38.5	'	64
Pre-tax gain (loss) due to change in fair value of assets and liabilities for which the fair value option was elected	-0.2	-0.5	-0.8	1.1	'
Credit risk portion of pre-tax gain (loss) due to change in fair value of assets for which the fair value option was elected	0	0	0	0	'
Number of loans which are more than 90 days past due or in nonaccrual status	0	0	0	0	'
Interest income	3.2	1.4	5.4	4.3	'
Obligations of Consolidated VIEs	'	'	'	'	'
Fair Value Option, Quantitative Disclosures	'	'	'	'	'
Fair value of liabilities for which the fair value option was elected	65.8	'	65.8	'	104.9
Aggregate unpaid principal amounts of obligations for which the fair value option was elected	138.9	'	138.9	'	174.4
Pre-tax gain (loss) due to change in fair value of assets and liabilities for which the fair value option was elected	10.4	-7.2	4.7	-26.3	'
Credit risk portion of pre-tax gain (loss) due to change in fair value of liabilities for which the fair value option was elected	8.9	-7.6	2.9	-27.5	'
Interest expense	2.7	0.9	3.8	2.7	'
Equity Method Investment	'	'	'	'	'
Fair Value Option, Quantitative Disclosures	'	'	'	'	'
Fair value of assets for which fair value option was elected	82.4	'	82.4	'	74.8
Pre-tax gain (loss) due to change in fair value of assets and liabilities for which the fair value option was elected	$4	$2.30	$7.60	$6.10	'

Fair_Value_Measurements_Detail6

Fair Value Measurements (Details 7) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets (liabilities)	'	'
Mortgage loans	$11,744.90	$11,533.60
Policy loans	837.7	859.7
Short-term debt	-126.3	-150.6
Long-term debt	-2,529.20	-2,601.40
Fair value hierarchy Level 1	'	'
Assets (liabilities)	'	'
Cash and cash equivalents not required to be reported at fair value	797.6	912.8
Bank deposits	-1,294.10	-1,252.20
Cash collateral payable	-79.6	-32.5
Fair value hierarchy Level 2	'	'
Assets (liabilities)	'	'
Other investments	164.6	140.9
Investment-type insurance contracts	-5,282.50	-5,902.20
Short-term debt	-126.3	-150.6
Long-term debt	-2,676.30	-2,639
Bank deposits	-659	-698.9
Fair value hierarchy Level 3	'	'
Assets (liabilities)	'	'
Mortgage loans	12,233.70	11,773.50
Policy loans	1,031.80	963.3
Other investments	30.9	33.8
Investment-type insurance contracts	-23,211.90	-24,190.90
Long-term debt	-80.3	-53.1
Separate account liabilities	-125,755	-118,059.70
Carrying amount	'	'
Assets (liabilities)	'	'
Mortgage loans	11,744.90	11,533.60
Policy loans	837.7	859.7
Other investments	195	174
Cash and cash equivalents not required to be reported at fair value	797.6	912.8
Investment-type insurance contracts	-28,371.80	-29,909.60
Short-term debt	-126.3	-150.6
Long-term debt	-2,529.20	-2,601.40
Separate account liabilities	-127,104.90	-119,500.70
Bank deposits	-1,946.70	-1,949
Cash collateral payable	-79.6	-32.5
Fair Value	'	'
Assets (liabilities)	'	'
Mortgage loans	12,233.70	11,773.50
Policy loans	1,031.80	963.3
Other investments	195.5	174.7
Cash and cash equivalents not required to be reported at fair value	797.6	912.8
Investment-type insurance contracts	-28,494.40	-30,093.10
Short-term debt	-126.3	-150.6
Long-term debt	-2,756.70	-2,692.10
Separate account liabilities	-125,755	-118,059.70
Bank deposits	-1,953.10	-1,951.10
Cash collateral payable	($79.60)	($32.50)

Segment_Information_Details

Segment Information (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Segment Information: Assets	'	'
Total assets	$216,422.80	$208,191.40
Retirement and Investor Services	'	'
Segment Information: Assets	'	'
Total assets	133,306.20	128,736.70
Principal Global Investors	'	'
Segment Information: Assets	'	'
Total assets	1,200.10	1,312.10
Principal International	'	'
Segment Information: Assets	'	'
Total assets	56,974.60	54,243.60
U.S. Insurance Solutions	'	'
Segment Information: Assets	'	'
Total assets	21,215	20,033.60
Corporate	'	'
Segment Information: Assets	'	'
Total assets	$3,726.90	$3,865.40

Segment_Information_Details_2

Segment Information (Details 2) (USD $)	3 Months Ended			9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information	'	'	'	'	'
Net realized capital gains (losses), net of related revenue adjustments	($68.20)	'	($76.70)	($25)	($253.40)
Total revenues	2,484.30	'	2,239.60	7,569.60	6,616.90
Net realized capital gains (losses), as adjusted	-55.2	'	-22.8	-47.3	-126.8
Net income (loss) available to common stockholders	240.7	'	245.7	840.7	646.3
Impact of court ruling on uncertain tax positions	'	-47.5	'	'	'
Operating Segments	'	'	'	'	'
Segment Reporting Information	'	'	'	'	'
Operating revenues	2,552.70	'	2,315.80	7,594.60	6,865.80
Operating earnings (loss)	353.7	'	269.2	993.9	773.9
Operating Segments | Retirement and Investor Services	'	'	'	'	'
Segment Reporting Information	'	'	'	'	'
Operating revenues	1,324.70	'	1,136.50	3,851	3,387.60
Operating earnings (loss)	204.3	'	172.9	632.9	515.2
Operating Segments | Principal Global Investors	'	'	'	'	'
Segment Reporting Information	'	'	'	'	'
Operating revenues	173.6	'	160.9	517.9	482.8
Operating earnings (loss)	25.3	'	23.1	79.6	72.4
Operating Segments | Principal International	'	'	'	'	'
Segment Reporting Information	'	'	'	'	'
Operating revenues	294.5	'	303.3	952.2	825.9
Operating earnings (loss)	73.8	'	50.7	205.1	153.6
Operating Segments | U.S. Insurance Solutions	'	'	'	'	'
Segment Reporting Information	'	'	'	'	'
Operating revenues	821	'	767.6	2,436.80	2,318.60
Operating earnings (loss)	83.3	'	54	175.7	136.9
Operating Segments | Corporate	'	'	'	'	'
Segment Reporting Information	'	'	'	'	'
Operating revenues	-61.1	'	-52.5	-163.3	-149.1
Operating earnings (loss)	-33	'	-31.5	-99.4	-104.2
Reconciling Items	'	'	'	'	'
Segment Reporting Information	'	'	'	'	'
Net realized capital gains (losses), net of related revenue adjustments	-68.2	'	-76.7	-25	-253.4
Exited group medical insurance business	-0.2	'	0.5	'	4.5
Net realized capital gains (losses), as adjusted	-55.2	'	-22.8	-47.3	-126.8
Other after-tax adjustments	-57.8	'	-0.7	-105.9	-0.8
Impact of enactment of tax legislation	-58.1	'	'	-58.1	'
Impact of court ruling on uncertain tax positions	'	'	'	-47.5	'
After-tax gains (losses) associated with exited group medical insurance business that does not qualify for discontinued operations	$0.30	'	($0.70)	($0.30)	($0.80)

Segment_Information_Details_3

Segment Information (Details 3) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Information: Net realized capital gains (losses), as adjusted	'	'	'	'
Net realized capital gains (losses)	($46.40)	($50.90)	$41	($181.90)
Certain derivative and hedging-related adjustments	-21.9	-25.6	-66.4	-70.7
Recognition of front-end fee (revenue) expense	0.1	-0.2	0.4	-0.8
Net realized capital gains (losses), net of related revenue adjustments	-68.2	-76.7	-25	-253.4
Amortization of deferred acquisition costs and other actuarial balances	-3.6	26.7	-26.8	44.8
Capital (gains) losses distributed	-8.8	-0.2	-18.1	-11.1
Certain market value adjustments of embedded derivatives	5.7	18.7	6	18.4
Noncontrolling interest capital (gains) losses	-0.1	-0.2	-0.2	-0.2
Tax expense/benefit related to net realized capital gains (losses), as adjusted	19.8	8.9	16.8	74.7
Net realized capital gains (losses), as adjusted	($55.20)	($22.80)	($47.30)	($126.80)

Segment_Information_Details_4

Segment Information (Details 4) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Operating Revenues for Products and Services	'	'	'	'
Total revenues	$2,484.30	$2,239.60	$7,569.60	$6,616.90
Net realized capital gains (losses), net of related revenue adjustments	-68.2	-76.7	-25	-253.4
Principal Global Investors	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Inter-segment revenues	71	61.1	214.4	179.9
Operating Segments	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	2,552.70	2,315.80	7,594.60	6,865.80
Operating Segments | Retirement and Investor Services	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	1,324.70	1,136.50	3,851	3,387.60
Operating Segments | Retirement and Investor Services | Total Accumulation	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	930.5	885.3	2,838.50	2,501.20
Operating Segments | Retirement and Investor Services | Full service accumulation	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	392.1	369.9	1,170	1,087.70
Operating Segments | Retirement and Investor Services | Principal Funds	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	219.7	194.8	638.2	565.9
Operating Segments | Retirement and Investor Services | Individual annuities	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	335.6	334.5	1,082.90	881.8
Operating Segments | Retirement and Investor Services | Bank and trust services	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	21.9	24.4	63.7	74.9
Operating Segments | Retirement and Investor Services | Accumulation Eliminations	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	-38.8	-38.3	-116.3	-109.1
Operating Segments | Retirement and Investor Services | Total Guaranteed	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	394.2	251.2	1,012.50	886.4
Operating Segments | Retirement and Investor Services | Investment only	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	73.4	83.1	234.5	260.6
Operating Segments | Retirement and Investor Services | Full service payout	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	320.8	168.1	778	625.8
Operating Segments | Principal Global Investors	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	173.6	160.9	517.9	482.8
Operating Segments | Principal International	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	294.5	303.3	952.2	825.9
Operating Segments | U.S. Insurance Solutions	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	821	767.6	2,436.80	2,318.60
Operating Segments | U.S. Insurance Solutions | Individual life insurance	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	382.7	362.7	1,148.50	1,110.20
Operating Segments | U.S. Insurance Solutions | Specialty benefits insurance	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	438.3	405	1,288.40	1,208.60
Operating Segments | U.S. Insurance Solutions | U.S. Insurance Solutions Eliminations	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	'	-0.1	-0.1	-0.2
Operating Segments | Corporate	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Operating revenues	-61.1	-52.5	-163.3	-149.1
Reconciling Items	'	'	'	'
Operating Revenues for Products and Services	'	'	'	'
Net realized capital gains (losses), net of related revenue adjustments	-68.2	-76.7	-25	-253.4
Exited group medical insurance business	($0.20)	$0.50	'	$4.50

StockBased_Compensation_Plans_1

Stock-Based Compensation Plans (Details) (USD $)	9 Months Ended			105 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2014	20-May-14
	Stock-Based Comp Plans	Stock-Based Comp Plans	2014 Stock Incentive Plan and 2014 Directors Stock Plan	Stock Incentive Plan, Directors Stock Plan and Long-Term Performance Plan	Amended and Restated 2010 Stock Incentive Plan and 2005 Directors Stock Plan
Stock-Based Compensation Plans - Disclosures	'	'	'	'	'
Number of shares that will be granted	'	'	'	'	0
Options granted (in shares)	'	'	'	0	'
Awards or units granted (in shares)	'	'	'	0	'
Maximum number of new shares of common stock available for grant (in shares)	'	'	13,200,000	'	'
Compensation cost	$50.30	$48.50	'	'	'
Related income tax benefit	16.4	14.6	'	'	'
Capitalized as part of an asset	$1.90	$1.90	'	'	'

StockBased_Compensation_Plans_2

Stock-Based Compensation Plans (Details 2) (USD $)	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014
2014 Stock Incentive Plan	'
Change in options outstanding	'
Options granted (in shares)	600,000
Assumptions used to estimate fair value of stock options granted during period	'
Weighted-average expected dividend yield (as a percent)	2.50%
Weighted-average expected volatility (as a percent)	53.20%
Weighted-average risk-free interest rate (as a percent)	2.00%
Weighted-average expected term	'6 years 6 months
Weighted-average estimated fair value of stock options granted (in dollars per share)	$18.89
Nonqualified Stock Options	'
Other nonqualified stock option disclosures	'
Unrecognized compensation costs	$5.10
Weighted-average service period over which unrecognized compensation costs will be recognized	'1 year 3 months 18 days

StockBased_Compensation_Plans_3

Stock-Based Compensation Plans (Details 3) (USD $)	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014
Performance Share Awards	'
Change in nonvested units outstanding	'
Awards or units granted (in shares)	300,000
Awards or units granted weighted-average grant-date fair value (in dollars per share)	$44.88
Other award and unit disclosures	'
Lower limit multiple of initial target awards (as a percent)	0.00%
Upper limit multiple of initial target awards (as a percent)	150.00%
Unrecognized compensation costs	$7.10
Weighted-average service period over which unrecognized compensation costs will be recognized	'1 year 3 months 18 days
Restricted Stock Units	'
Change in nonvested units outstanding	'
Awards or units granted (in shares)	900,000
Awards or units granted weighted-average grant-date fair value (in dollars per share)	$45.01
Other award and unit disclosures	'
Unrecognized compensation costs	$49.80
Weighted-average service period over which unrecognized compensation costs will be recognized	'1 year 9 months 18 days

StockBased_Compensation_Plans_4

Stock-Based Compensation Plans (Details 4) (Employee Stock Purchase Plan, USD $)	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014
Employee Stock Purchase Plan	'
Stock-Based Compensation Plans - Disclosures	'
Share purchases under employee stock purchase plan (in shares)	0.3
Weighted-average fair value of discount on employee stock purchase plan (in dollars per share)	$9.15
Shares available to be issued under employee stock purchase plan (in shares)	4.9

Earnings_Per_Common_Share_Deta

Earnings Per Common Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Common Share	'	'	'	'
Net income (loss)	$252.80	$259.10	$896.10	$685.70
Subtract:	'	'	'	'
Net income (loss) attributable to noncontrolling interest	3.9	5.2	30.7	14.7
Preferred stock dividends	8.2	8.2	24.7	24.7
Adjustments to redemption amounts of redeemable noncontrolling interests	10.3	'	19.7	'
Total	$230.40	$245.70	$821	$646.30
Weighted-average shares outstanding	'	'	'	'
Basic	294.2	294.9	294.9	294.4
Dilutive effects:	'	'	'	'
Stock options	1.8	1.7	1.7	1.4
Restricted stock units	1.8	1.7	1.7	1.6
Performance share awards	0.4	0.3	0.4	0.3
Diluted	298.2	298.6	298.7	297.7
Net income (loss) per common share:	'	'	'	'
Basic	$0.78	$0.83	$2.78	$2.20
Diluted	$0.77	$0.82	$2.75	$2.17

Condensed_Consolidating_Financ2

Condensed Consolidating Financial Information (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Assets	'	'	'	'
Fixed maturities, available-for-sale	$49,627.50	$48,757.10	'	'
Fixed maturities, trading	609.4	563.1	'	'
Equity securities, available-for-sale	124.8	110.5	'	'
Equity securities, trading	807.6	716.9	'	'
Mortgage loans	11,744.90	11,533.60	'	'
Real estate	1,352.10	1,271.60	'	'
Policy loans	837.7	859.7	'	'
Investment in unconsolidated entities	873.4	880	'	'
Other investments	2,117.50	2,064.40	'	'
Cash and cash equivalents	1,270.80	2,371.80	1,707.10	4,177.20
Accrued investment income	545.1	532.1	'	'
Premiums due and other receivables	1,189.30	1,241	'	'
Deferred acquisition costs	2,985.40	3,077	'	'
Property and equipment	590.1	500.7	'	'
Goodwill	1,034.40	1,100.30	'	'
Other intangibles	1,361.40	1,459	'	'
Separate account assets	138,296.70	130,018.40	'	'
Other assets	1,054.70	1,134.20	'	'
Total assets	216,422.80	208,191.40	'	'
Liabilities	'	'	'	'
Contractholder funds	34,680.80	35,958.30	'	'
Future policy benefits and claims	23,399.50	22,626.20	'	'
Other policyholder funds	811.9	758.9	'	'
Short-term debt	126.3	150.6	'	'
Long-term debt	2,529.20	2,601.40	'	'
Income taxes currently payable	18.1	5.2	'	'
Deferred income taxes	1,150.60	824	'	'
Separate account liabilities	138,296.70	130,018.40	'	'
Other liabilities	4,984.60	5,224.20	'	'
Total liabilities	205,997.70	198,167.20	'	'
Redeemable noncontrolling interest	56.1	247.2	234.5	60.4
Stockholders' equity	'	'	'	'
Common stock	4.6	4.6	'	'
Additional paid-in capital	9,916.90	9,798.90	'	'
Retained earnings (accumulated deficit)	5,945.20	5,405.40	'	'
Accumulated other comprehensive income	380.1	183.2	'	'
Treasury stock, at cost (168.8 million and 164.1 million shares in 2014 and 2013)	-5,930.50	-5,708	'	'
Total stockholders' equity attributable to Principal Financial Group, Inc.	10,316.40	9,684.20	'	'
Noncontrolling interest	52.6	92.8	'	'
Total stockholders' equity	10,369	9,777	9,373.40	9,703.40
Total liabilities and stockholders' equity	216,422.80	208,191.40	'	'
Principal Financial Group, Inc. Parent Only	'	'	'	'
Assets	'	'	'	'
Investment in unconsolidated entities	12,583.20	11,956.20	'	'
Other investments	9.5	9.3	'	'
Cash and cash equivalents	150.7	131.5	50.8	207.1
Other assets	62.4	59.2	'	'
Total assets	12,805.80	12,156.20	'	'
Liabilities	'	'	'	'
Long-term debt	2,448.90	2,448.80	'	'
Other liabilities	40.5	23.2	'	'
Total liabilities	2,489.40	2,472	'	'
Stockholders' equity	'	'	'	'
Common stock	4.6	4.6	'	'
Additional paid-in capital	9,916.90	9,798.90	'	'
Retained earnings (accumulated deficit)	5,945.20	5,405.40	'	'
Accumulated other comprehensive income	380.1	183.2	'	'
Treasury stock, at cost (168.8 million and 164.1 million shares in 2014 and 2013)	-5,930.50	-5,708	'	'
Total stockholders' equity attributable to Principal Financial Group, Inc.	10,316.40	9,684.20	'	'
Total stockholders' equity	10,316.40	9,684.20	'	'
Total liabilities and stockholders' equity	12,805.80	12,156.20	'	'
Principal Life Insurance Company Only	'	'	'	'
Assets	'	'	'	'
Fixed maturities, available-for-sale	43,630.40	42,794.70	'	'
Fixed maturities, trading	308.7	245.5	'	'
Equity securities, available-for-sale	109.4	102.6	'	'
Equity securities, trading	0.3	0.3	'	'
Mortgage loans	10,842	10,501.50	'	'
Real estate	6.9	7.9	'	'
Policy loans	808.4	830.1	'	'
Investment in unconsolidated entities	3,180.20	3,396.80	'	'
Other investments	2,723.90	1,892.40	'	'
Cash and cash equivalents	149.1	1,332.20	651.6	1,698.40
Accrued investment income	488	474.5	'	'
Premiums due and other receivables	1,222.90	1,029	'	'
Deferred acquisition costs	2,739.30	2,848.80	'	'
Property and equipment	504.2	422.1	'	'
Goodwill	54.3	54.3	'	'
Other intangibles	26	26.9	'	'
Separate account assets	89,167.70	83,790.20	'	'
Other assets	963.2	976.9	'	'
Total assets	156,924.90	150,726.70	'	'
Liabilities	'	'	'	'
Contractholder funds	33,458	34,918	'	'
Future policy benefits and claims	19,164.80	18,292.90	'	'
Other policyholder funds	747.7	705.1	'	'
Long-term debt	'	99.4	'	'
Deferred income taxes	337	-25	'	'
Separate account liabilities	89,167.70	83,790.20	'	'
Other liabilities	5,725.40	5,204.80	'	'
Total liabilities	148,600.60	142,985.40	'	'
Stockholders' equity	'	'	'	'
Common stock	2.5	2.5	'	'
Additional paid-in capital	5,511.30	5,505	'	'
Retained earnings (accumulated deficit)	1,978.50	1,738.10	'	'
Accumulated other comprehensive income	832	495.7	'	'
Total stockholders' equity attributable to Principal Financial Group, Inc.	8,324.30	7,741.30	'	'
Total stockholders' equity	8,324.30	7,741.30	'	'
Total liabilities and stockholders' equity	156,924.90	150,726.70	'	'
Principal Financial Services, Inc. and Other Subsidiaries Combined	'	'	'	'
Assets	'	'	'	'
Fixed maturities, available-for-sale	6,394.60	6,357.50	'	'
Fixed maturities, trading	300.7	317.6	'	'
Equity securities, available-for-sale	15.4	7.9	'	'
Equity securities, trading	807.3	716.6	'	'
Mortgage loans	1,245	1,345.90	'	'
Real estate	1,345.20	1,263.70	'	'
Policy loans	29.3	29.6	'	'
Investment in unconsolidated entities	5,539.40	4,891.60	'	'
Other investments	1,396.20	1,238.80	'	'
Cash and cash equivalents	833.5	894.5	934.8	2,286.90
Accrued investment income	58.3	59	'	'
Premiums due and other receivables	2,022.70	1,814.50	'	'
Deferred acquisition costs	246.1	228.2	'	'
Property and equipment	85.9	78.6	'	'
Goodwill	980.1	1,046	'	'
Other intangibles	1,335.40	1,432.10	'	'
Separate account assets	49,129	46,228.20	'	'
Other assets	2,591.50	2,115.30	'	'
Total assets	74,355.60	70,065.60	'	'
Liabilities	'	'	'	'
Contractholder funds	1,527.50	1,330.70	'	'
Future policy benefits and claims	4,634.90	4,625	'	'
Other policyholder funds	64.9	54.2	'	'
Short-term debt	126.3	150.6	'	'
Long-term debt	409.3	367	'	'
Income taxes currently payable	124.3	67.4	'	'
Deferred income taxes	1,055.40	1,030.10	'	'
Separate account liabilities	49,129	46,228.20	'	'
Other liabilities	4,587.50	3,911.80	'	'
Total liabilities	61,659.10	57,765	'	'
Redeemable noncontrolling interest	56.1	247.2	'	'
Stockholders' equity	'	'	'	'
Additional paid-in capital	9,191.90	9,163.70	'	'
Retained earnings (accumulated deficit)	2,983.40	2,578.20	'	'
Accumulated other comprehensive income	407.9	214.3	'	'
Total stockholders' equity attributable to Principal Financial Group, Inc.	12,583.20	11,956.20	'	'
Noncontrolling interest	57.2	97.2	'	'
Total stockholders' equity	12,640.40	12,053.40	'	'
Total liabilities and stockholders' equity	74,355.60	70,065.60	'	'
Eliminations, Notes Guarantor	'	'	'	'
Assets	'	'	'	'
Fixed maturities, available-for-sale	-397.5	-395.1	'	'
Mortgage loans	-342.1	-313.8	'	'
Investment in unconsolidated entities	-20,429.40	-19,364.60	'	'
Other investments	-2,012.10	-1,076.10	'	'
Cash and cash equivalents	137.5	13.6	69.9	-15.2
Accrued investment income	-1.2	-1.4	'	'
Premiums due and other receivables	-2,056.30	-1,602.50	'	'
Other assets	-2,562.40	-2,017.20	'	'
Total assets	-27,663.50	-24,757.10	'	'
Liabilities	'	'	'	'
Contractholder funds	-304.7	-290.4	'	'
Future policy benefits and claims	-400.2	-291.7	'	'
Other policyholder funds	-0.7	-0.4	'	'
Long-term debt	-329	-313.8	'	'
Income taxes currently payable	-106.2	-62.2	'	'
Deferred income taxes	-241.8	-181.1	'	'
Other liabilities	-5,368.80	-3,915.60	'	'
Total liabilities	-6,751.40	-5,055.20	'	'
Stockholders' equity	'	'	'	'
Common stock	-2.5	-2.5	'	'
Additional paid-in capital	-14,703.20	-14,668.70	'	'
Retained earnings (accumulated deficit)	-4,961.90	-4,316.30	'	'
Accumulated other comprehensive income	-1,239.90	-710	'	'
Total stockholders' equity attributable to Principal Financial Group, Inc.	-20,907.50	-19,697.50	'	'
Noncontrolling interest	-4.6	-4.4	'	'
Total stockholders' equity	-20,912.10	-19,701.90	'	'
Total liabilities and stockholders' equity	-27,663.50	-24,757.10	'	'
Series A	'	'	'	'
Stockholders' equity	'	'	'	'
Preferred stock, value	'	'	'	'
Total stockholders' equity	0	0	0	0
Series A | Principal Financial Group, Inc. Parent Only	'	'	'	'
Stockholders' equity	'	'	'	'
Preferred stock, value	'	'	'	'
Series B	'	'	'	'
Stockholders' equity	'	'	'	'
Preferred stock, value	0.1	0.1	'	'
Total stockholders' equity	0.1	0.1	0.1	0.1
Series B | Principal Financial Group, Inc. Parent Only	'	'	'	'
Stockholders' equity	'	'	'	'
Preferred stock, value	$0.10	$0.10	'	'

Condensed_Consolidating_Financ3

Condensed Consolidating Financial Information (Details 2) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues	'	'	'	'
Premiums and other considerations	$875.80	$703	$2,514.80	$2,134.90
Fees and other revenues	884.5	803	2,569.70	2,340.40
Net investment income (loss)	770.4	784.5	2,444.10	2,323.50
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	-24.5	-29.7	105	-109.5
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	-7.3	-11.9	18.5	-81.2
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	-14.6	-9.3	-82.5	8.8
Net impairment losses on available-for-sale securities	'	'	-64	-72.4
Net realized capital gains (losses)	-46.4	-50.9	41	-181.9
Total revenues	2,484.30	2,239.60	7,569.60	6,616.90
Expenses	'	'	'	'
Benefits, claims and settlement expenses	1,113.80	1,096.20	3,609.70	3,286.40
Dividends to policyholders	44.2	48.5	134.5	144.3
Operating expenses	932.5	774.6	2,647.70	2,372.10
Total expenses	2,090.50	1,919.30	6,391.90	5,802.80
Income (loss) before income taxes	393.8	320.3	1,177.70	814.1
Income taxes (benefits)	141	61.2	281.6	128.4
Net income (loss)	252.8	259.1	896.1	685.7
Net income (loss) attributable to noncontrolling interest	3.9	5.2	30.7	14.7
Net income (loss) attributable to Principal Financial Group, Inc.	248.9	253.9	865.4	671
Preferred stock dividends	8.2	8.2	24.7	24.7
Net income (loss) available to common stockholders	240.7	245.7	840.7	646.3
Net income (loss)	252.8	259.1	896.1	685.7
Other comprehensive income (loss)	-225.9	-18	190.1	-668.3
Comprehensive income (loss)	26.9	241.1	1,086.20	17.4
Principal Financial Group, Inc. Parent Only	'	'	'	'
Revenues	'	'	'	'
Net investment income (loss)	'	'	0.4	0.4
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	'	'	'	6.3
Net realized capital gains (losses)	'	'	'	6.3
Total revenues	'	'	0.4	6.7
Expenses	'	'	'	'
Operating expenses	'	'	106.8	105.2
Total expenses	'	'	106.8	105.2
Income (loss) before income taxes	'	'	-106.4	-98.5
Income taxes (benefits)	'	'	-42.7	-39.4
Equity in the net income (loss) of subsidiaries	'	'	929.1	730.1
Net income (loss)	'	'	865.4	671
Net income (loss) attributable to Principal Financial Group, Inc.	'	'	865.4	671
Preferred stock dividends	'	'	24.7	24.7
Net income (loss) available to common stockholders	'	'	840.7	646.3
Net income (loss)	'	'	865.4	671
Other comprehensive income (loss)	'	'	129.6	-683.9
Comprehensive income (loss)	'	'	995	-12.9
Principal Life Insurance Company Only	'	'	'	'
Revenues	'	'	'	'
Premiums and other considerations	'	'	2,200.50	1,853.60
Fees and other revenues	'	'	1,407.50	1,272.30
Net investment income (loss)	'	'	1,719.40	1,775.70
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	'	'	674.1	-630.7
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	'	'	27.7	-75.4
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	'	'	-84.5	11.4
Net impairment losses on available-for-sale securities	'	'	-56.8	-64
Net realized capital gains (losses)	'	'	617.3	-694.7
Total revenues	'	'	5,944.70	4,206.90
Expenses	'	'	'	'
Benefits, claims and settlement expenses	'	'	3,083.80	2,828.80
Dividends to policyholders	'	'	134.5	144.3
Operating expenses	'	'	1,624.30	1,378.60
Total expenses	'	'	4,842.60	4,351.70
Income (loss) before income taxes	'	'	1,102.10	-144.8
Income taxes (benefits)	'	'	260.6	-136
Equity in the net income (loss) of subsidiaries	'	'	-125	530.2
Net income (loss)	'	'	716.5	521.4
Net income (loss) attributable to Principal Financial Group, Inc.	'	'	716.5	521.4
Net income (loss) available to common stockholders	'	'	716.5	521.4
Net income (loss)	'	'	716.5	521.4
Other comprehensive income (loss)	'	'	334.8	-438.6
Comprehensive income (loss)	'	'	1,051.30	82.8
Principal Financial Services, Inc. and Other Subsidiaries Combined	'	'	'	'
Revenues	'	'	'	'
Premiums and other considerations	'	'	314.3	281.3
Fees and other revenues	'	'	1,451.50	1,325.80
Net investment income (loss)	'	'	1,260.10	526.5
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	'	'	-569.1	514.8
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	'	'	-9.2	-5.8
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	'	'	2	-2.6
Net impairment losses on available-for-sale securities	'	'	-7.2	-8.4
Net realized capital gains (losses)	'	'	-576.3	506.4
Total revenues	'	'	2,449.60	2,640
Expenses	'	'	'	'
Benefits, claims and settlement expenses	'	'	534.5	466.7
Operating expenses	'	'	1,156.40	1,113.20
Total expenses	'	'	1,690.90	1,579.90
Income (loss) before income taxes	'	'	758.7	1,060.10
Income taxes (benefits)	'	'	65.3	304
Equity in the net income (loss) of subsidiaries	'	'	266.4	-11.2
Net income (loss)	'	'	959.8	744.9
Net income (loss) attributable to noncontrolling interest	'	'	30.7	14.8
Net income (loss) attributable to Principal Financial Group, Inc.	'	'	929.1	730.1
Net income (loss) available to common stockholders	'	'	929.1	730.1
Net income (loss)	'	'	959.8	744.9
Other comprehensive income (loss)	'	'	275.7	-225.6
Comprehensive income (loss)	'	'	1,235.50	519.3
Eliminations, Notes Guarantor	'	'	'	'
Revenues	'	'	'	'
Fees and other revenues	'	'	-289.3	-257.7
Net investment income (loss)	'	'	-535.8	20.9
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	'	'	'	0.1
Net realized capital gains (losses)	'	'	'	0.1
Total revenues	'	'	-825.1	-236.7
Expenses	'	'	'	'
Benefits, claims and settlement expenses	'	'	-8.6	-9.1
Operating expenses	'	'	-239.8	-224.9
Total expenses	'	'	-248.4	-234
Income (loss) before income taxes	'	'	-576.7	-2.7
Income taxes (benefits)	'	'	-1.6	-0.2
Equity in the net income (loss) of subsidiaries	'	'	-1,070.50	-1,249.10
Net income (loss)	'	'	-1,645.60	-1,251.60
Net income (loss) attributable to noncontrolling interest	'	'	'	-0.1
Net income (loss) attributable to Principal Financial Group, Inc.	'	'	-1,645.60	-1,251.50
Net income (loss) available to common stockholders	'	'	-1,645.60	-1,251.50
Net income (loss)	'	'	-1,645.60	-1,251.60
Other comprehensive income (loss)	'	'	-550	679.8
Comprehensive income (loss)	'	'	($2,195.60)	($571.80)

Condensed_Consolidating_Financ4

Condensed Consolidating Financial Information (Details 3) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Operating activities	'	'
Net cash provided by (used in) operating activities	$2,197.60	$1,397.90
Investing activities	'	'
Available-for-sale securities: Purchases	-6,596	-7,012.30
Available-for-sale securities: Sales	1,871.50	1,626.70
Available-for-sale securities: Maturities	4,499.30	5,783.20
Mortgage loans acquired or originated	-1,614.20	-2,020
Mortgage loans sold or repaid	1,319.80	1,570.80
Real estate acquired	-246.8	-59
Net (purchases) sales of property and equipment	-117.5	-22.7
Purchases of interest in subsidiaries, net of cash acquired	'	-1,268.30
Net change in other investments	56.6	-31.2
Net cash provided by (used in) investing activities	-827.3	-1,432.80
Financing activities	'	'
Issuance of common stock	69.6	80.2
Acquisition of treasury stock	-222.5	-153.4
Proceeds from financing element derivatives	14.9	46.7
Payments for financing element derivatives	-41.5	-36.9
Excess tax benefits from share-based payment arrangements	8.6	8.6
Purchase of subsidiary shares from noncontrolling interest	-222.4	-51.4
Sale of subsidiary shares to noncontrolling interest	'	31.8
Dividends to common stockholders	-276.7	-211.7
Dividends to preferred stockholders	-24.7	-24.7
Issuance of long-term debt	36.5	24.1
Principal repayments of long-term debt	-100.3	-212.2
Net proceeds from (repayments of) short-term borrowings	-20.5	131.6
Investment contract deposits	4,184.30	5,270.20
Investment contract withdrawals	-5,864.30	-7,055.60
Net increase (decrease) in banking operation deposits	-2.3	-276.2
Other	-10	-6.3
Net cash provided by (used in) financing activities	-2,471.30	-2,435.20
Net increase (decrease) in cash and cash equivalents	-1,101	-2,470.10
Cash and cash equivalents at beginning of period	2,371.80	4,177.20
Cash and cash equivalents at end of period	1,270.80	1,707.10
Principal Financial Group, Inc. Parent Only	'	'
Operating activities	'	'
Net cash provided by (used in) operating activities	-42.3	-12.8
Investing activities	'	'
Dividends and returns of capital received from (contributions to) unconsolidated entities	517.5	169.3
Net change in other investments	-2	-3.2
Net cash provided by (used in) investing activities	515.5	166.1
Financing activities	'	'
Issuance of common stock	69.6	80.2
Acquisition of treasury stock	-222.5	-153.4
Excess tax benefits from share-based payment arrangements	0.3	'
Dividends to common stockholders	-276.7	-211.7
Dividends to preferred stockholders	-24.7	-24.7
Net cash provided by (used in) financing activities	-454	-309.6
Net increase (decrease) in cash and cash equivalents	19.2	-156.3
Cash and cash equivalents at beginning of period	131.5	207.1
Cash and cash equivalents at end of period	150.7	50.8
Principal Life Insurance Company Only	'	'
Operating activities	'	'
Net cash provided by (used in) operating activities	1,729.90	1,412.50
Investing activities	'	'
Available-for-sale securities: Purchases	-5,902.20	-6,094
Available-for-sale securities: Sales	1,559.70	1,281.40
Available-for-sale securities: Maturities	4,149.40	5,186.50
Mortgage loans acquired or originated	-1,620.60	-2,226.30
Mortgage loans sold or repaid	1,291.50	1,408.30
Real estate acquired	-0.6	'
Net (purchases) sales of property and equipment	-90.3	-20.2
Dividends and returns of capital received from (contributions to) unconsolidated entities	263.5	157.9
Net change in other investments	-83.6	76.1
Net cash provided by (used in) investing activities	-433.2	-230.3
Financing activities	'	'
Issuance of common stock	-0.2	'
Proceeds from financing element derivatives	14.9	46.7
Payments for financing element derivatives	-41.5	-36.9
Excess tax benefits from share-based payment arrangements	3.7	2.5
Principal repayments of long-term debt	-100	'
Capital received from (dividends and capital paid to) parent	-467.5	-169.3
Investment contract deposits	3,978.20	4,985.40
Investment contract withdrawals	-5,857.30	-7,051.10
Other	-10.1	-6.3
Net cash provided by (used in) financing activities	-2,479.80	-2,229
Net increase (decrease) in cash and cash equivalents	-1,183.10	-1,046.80
Cash and cash equivalents at beginning of period	1,332.20	1,698.40
Cash and cash equivalents at end of period	149.1	651.6
Principal Financial Services, Inc. and Other Subsidiaries Combined	'	'
Operating activities	'	'
Net cash provided by (used in) operating activities	504.6	-132.2
Investing activities	'	'
Available-for-sale securities: Purchases	-705.1	-926.7
Available-for-sale securities: Sales	311.8	370.1
Available-for-sale securities: Maturities	349.9	596.7
Mortgage loans acquired or originated	-118.1	-175.6
Mortgage loans sold or repaid	137.6	583.2
Real estate acquired	-246.2	-59
Net (purchases) sales of property and equipment	-27.2	-2.5
Purchases of interest in subsidiaries, net of cash acquired	'	-1,268.30
Dividends and returns of capital received from (contributions to) unconsolidated entities	467.5	169.3
Net change in other investments	34.9	-128.4
Net cash provided by (used in) investing activities	205.1	-841.2
Financing activities	'	'
Issuance of common stock	0.2	'
Excess tax benefits from share-based payment arrangements	4.6	6.1
Purchase of subsidiary shares from noncontrolling interest	-222.7	-51.4
Sale of subsidiary shares to noncontrolling interest	0.3	31.8
Issuance of long-term debt	138.9	24.1
Principal repayments of long-term debt	-87.4	-197.8
Net proceeds from (repayments of) short-term borrowings	-20.5	131.6
Capital received from (dividends and capital paid to) parent	-781	-327.2
Investment contract deposits	206.1	284.8
Investment contract withdrawals	-7	-4.5
Net increase (decrease) in banking operation deposits	-2.3	-276.2
Other	0.1	'
Net cash provided by (used in) financing activities	-770.7	-378.7
Net increase (decrease) in cash and cash equivalents	-61	-1,352.10
Cash and cash equivalents at beginning of period	894.5	2,286.90
Cash and cash equivalents at end of period	833.5	934.8
Eliminations, Notes Guarantor	'	'
Operating activities	'	'
Net cash provided by (used in) operating activities	5.4	130.4
Investing activities	'	'
Available-for-sale securities: Purchases	11.3	8.4
Available-for-sale securities: Sales	'	-24.8
Mortgage loans acquired or originated	124.5	381.9
Mortgage loans sold or repaid	-109.3	-420.7
Dividends and returns of capital received from (contributions to) unconsolidated entities	-1,248.50	-496.5
Net change in other investments	107.3	24.3
Net cash provided by (used in) investing activities	-1,114.70	-527.4
Financing activities	'	'
Purchase of subsidiary shares from noncontrolling interest	0.3	'
Sale of subsidiary shares to noncontrolling interest	-0.3	'
Issuance of long-term debt	-102.4	'
Principal repayments of long-term debt	87.1	-14.4
Capital received from (dividends and capital paid to) parent	1,248.50	496.5
Net cash provided by (used in) financing activities	1,233.20	482.1
Net increase (decrease) in cash and cash equivalents	123.9	85.1
Cash and cash equivalents at beginning of period	13.6	-15.2
Cash and cash equivalents at end of period	$137.50	$69.90

Condensed_Consolidating_Financ5

Condensed Consolidating Financial Information (Details 4) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Assets	'	'	'	'
Fixed maturities, available-for-sale	$49,627.50	$48,757.10	'	'
Fixed maturities, trading	609.4	563.1	'	'
Equity securities, available-for-sale	124.8	110.5	'	'
Equity securities, trading	807.6	716.9	'	'
Mortgage loans	11,744.90	11,533.60	'	'
Real estate	1,352.10	1,271.60	'	'
Policy loans	837.7	859.7	'	'
Investment in unconsolidated entities	873.4	880	'	'
Other investments	2,117.50	2,064.40	'	'
Cash and cash equivalents	1,270.80	2,371.80	1,707.10	4,177.20
Accrued investment income	545.1	532.1	'	'
Premiums due and other receivables	1,189.30	1,241	'	'
Deferred acquisition costs	2,985.40	3,077	'	'
Property and equipment	590.1	500.7	'	'
Goodwill	1,034.40	1,100.30	'	'
Other intangibles	1,361.40	1,459	'	'
Separate account assets	138,296.70	130,018.40	'	'
Other assets	1,054.70	1,134.20	'	'
Total assets	216,422.80	208,191.40	'	'
Liabilities	'	'	'	'
Contractholder funds	34,680.80	35,958.30	'	'
Future policy benefits and claims	23,399.50	22,626.20	'	'
Other policyholder funds	811.9	758.9	'	'
Short-term debt	126.3	150.6	'	'
Long-term debt	2,529.20	2,601.40	'	'
Income taxes currently payable	18.1	5.2	'	'
Deferred income taxes	1,150.60	824	'	'
Separate account liabilities	138,296.70	130,018.40	'	'
Other liabilities	4,984.60	5,224.20	'	'
Total liabilities	205,997.70	198,167.20	'	'
Redeemable noncontrolling interest	56.1	247.2	234.5	60.4
Stockholders' equity	'	'	'	'
Common stock	4.6	4.6	'	'
Additional paid-in capital	9,916.90	9,798.90	'	'
Retained earnings (accumulated deficit)	5,945.20	5,405.40	'	'
Accumulated other comprehensive income	380.1	183.2	'	'
Treasury stock, at cost (168.8 million and 164.1 million shares in 2014 and 2013)	-5,930.50	-5,708	'	'
Total stockholders' equity attributable to Principal Financial Group, Inc.	10,316.40	9,684.20	'	'
Noncontrolling interest	52.6	92.8	'	'
Total stockholders' equity	10,369	9,777	9,373.40	9,703.40
Total liabilities and stockholders' equity	216,422.80	208,191.40	'	'
Principal Financial Group, Inc. Parent Only	'	'	'	'
Assets	'	'	'	'
Investment in unconsolidated entities	12,583.20	11,956.20	'	'
Other investments	9.5	9.3	'	'
Cash and cash equivalents	150.7	131.5	50.8	207.1
Other assets	62.4	59.2	'	'
Total assets	12,805.80	12,156.20	'	'
Liabilities	'	'	'	'
Long-term debt	2,448.90	2,448.80	'	'
Other liabilities	40.5	23.2	'	'
Total liabilities	2,489.40	2,472	'	'
Stockholders' equity	'	'	'	'
Common stock	4.6	4.6	'	'
Additional paid-in capital	9,916.90	9,798.90	'	'
Retained earnings (accumulated deficit)	5,945.20	5,405.40	'	'
Accumulated other comprehensive income	380.1	183.2	'	'
Treasury stock, at cost (168.8 million and 164.1 million shares in 2014 and 2013)	-5,930.50	-5,708	'	'
Total stockholders' equity attributable to Principal Financial Group, Inc.	10,316.40	9,684.20	'	'
Total stockholders' equity	10,316.40	9,684.20	'	'
Total liabilities and stockholders' equity	12,805.80	12,156.20	'	'
Principal Financial Services, Inc. Only	'	'	'	'
Assets	'	'	'	'
Investment in unconsolidated entities	12,103.70	11,647.60	'	'
Other investments	179	72.7	'	'
Cash and cash equivalents	413	688.7	491	612.5
Premiums due and other receivables	0.6	0.1	'	'
Other assets	152.9	94.8	'	'
Total assets	12,849.20	12,503.90	'	'
Liabilities	'	'	'	'
Income taxes currently payable	16	2.8	'	'
Other liabilities	250	544.9	'	'
Total liabilities	266	547.7	'	'
Stockholders' equity	'	'	'	'
Additional paid-in capital	9,191.90	9,163.70	'	'
Retained earnings (accumulated deficit)	2,983.40	2,578.20	'	'
Accumulated other comprehensive income	407.9	214.3	'	'
Total stockholders' equity attributable to Principal Financial Group, Inc.	12,583.20	11,956.20	'	'
Total stockholders' equity	12,583.20	11,956.20	'	'
Total liabilities and stockholders' equity	12,849.20	12,503.90	'	'
Principal Life Insurance Company and Other Subsidiaries Combined	'	'	'	'
Assets	'	'	'	'
Fixed maturities, available-for-sale	49,627.50	48,757.10	'	'
Fixed maturities, trading	609.4	563.1	'	'
Equity securities, available-for-sale	124.8	110.5	'	'
Equity securities, trading	807.6	716.9	'	'
Mortgage loans	11,744.90	11,533.60	'	'
Real estate	1,352.10	1,271.60	'	'
Policy loans	837.7	859.7	'	'
Investment in unconsolidated entities	841.4	879.8	'	'
Other investments	1,929	1,982.50	'	'
Cash and cash equivalents	1,196.40	2,384	1,822.10	4,241.30
Accrued investment income	545.1	532.1	'	'
Premiums due and other receivables	1,188.30	2,330.40	'	'
Deferred acquisition costs	2,985.40	3,077	'	'
Property and equipment	590.1	500.7	'	'
Goodwill	1,034.40	1,100.30	'	'
Other intangibles	1,361.40	1,459	'	'
Separate account assets	138,296.70	130,018.40	'	'
Other assets	1,136.60	1,181	'	'
Total assets	216,208.80	209,257.70	'	'
Liabilities	'	'	'	'
Contractholder funds	34,680.80	35,958.30	'	'
Future policy benefits and claims	23,399.50	22,626.20	'	'
Other policyholder funds	811.9	758.9	'	'
Short-term debt	325.4	443	'	'
Long-term debt	80.3	1,236.90	'	'
Income taxes currently payable	83.9	44.7	'	'
Deferred income taxes	1,361.60	979.6	'	'
Separate account liabilities	138,296.70	130,018.40	'	'
Other liabilities	4,956.30	5,204.10	'	'
Total liabilities	203,996.40	197,270.10	'	'
Redeemable noncontrolling interest	56.1	247.2	'	'
Stockholders' equity	'	'	'	'
Common stock	17.8	17.8	'	'
Additional paid-in capital	9,284.20	9,057.10	'	'
Retained earnings (accumulated deficit)	2,450.20	2,387.20	'	'
Accumulated other comprehensive income	353.5	187.5	'	'
Treasury stock, at cost (168.8 million and 164.1 million shares in 2014 and 2013)	-2	-2	'	'
Total stockholders' equity attributable to Principal Financial Group, Inc.	12,103.70	11,647.60	'	'
Noncontrolling interest	52.6	92.8	'	'
Total stockholders' equity	12,156.30	11,740.40	'	'
Total liabilities and stockholders' equity	216,208.80	209,257.70	'	'
Eliminations, Shelf Registration Debt Guarantor	'	'	'	'
Assets	'	'	'	'
Investment in unconsolidated entities	-24,654.90	-23,603.60	'	'
Other investments	'	-0.1	'	'
Cash and cash equivalents	-489.3	-832.4	-656.8	-883.7
Premiums due and other receivables	0.4	-1,089.50	'	'
Other assets	-297.2	-200.8	'	'
Total assets	-25,441	-25,726.40	'	'
Liabilities	'	'	'	'
Short-term debt	-199.1	-292.4	'	'
Long-term debt	'	-1,084.30	'	'
Income taxes currently payable	-81.8	-42.3	'	'
Deferred income taxes	-211	-155.6	'	'
Other liabilities	-262.2	-548	'	'
Total liabilities	-754.1	-2,122.60	'	'
Stockholders' equity	'	'	'	'
Common stock	-17.8	-17.8	'	'
Additional paid-in capital	-18,476.10	-18,220.80	'	'
Retained earnings (accumulated deficit)	-5,433.60	-4,965.40	'	'
Accumulated other comprehensive income	-761.4	-401.8	'	'
Treasury stock, at cost (168.8 million and 164.1 million shares in 2014 and 2013)	2	2	'	'
Total stockholders' equity attributable to Principal Financial Group, Inc.	-24,686.90	-23,603.80	'	'
Total stockholders' equity	-24,686.90	-23,603.80	'	'
Total liabilities and stockholders' equity	-25,441	-25,726.40	'	'
Series A	'	'	'	'
Stockholders' equity	'	'	'	'
Preferred stock, value	'	'	'	'
Total stockholders' equity	0	0	0	0
Series A | Principal Financial Group, Inc. Parent Only	'	'	'	'
Stockholders' equity	'	'	'	'
Preferred stock, value	'	'	'	'
Series B	'	'	'	'
Stockholders' equity	'	'	'	'
Preferred stock, value	0.1	0.1	'	'
Total stockholders' equity	0.1	0.1	0.1	0.1
Series B | Principal Financial Group, Inc. Parent Only	'	'	'	'
Stockholders' equity	'	'	'	'
Preferred stock, value	$0.10	$0.10	'	'

Condensed_Consolidating_Financ6

Condensed Consolidating Financial Information (Details 5) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Revenues	'	'	'	'
Premiums and other considerations	$875.80	$703	$2,514.80	$2,134.90
Fees and other revenues	884.5	803	2,569.70	2,340.40
Net investment income (loss)	770.4	784.5	2,444.10	2,323.50
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	-24.5	-29.7	105	-109.5
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	-7.3	-11.9	18.5	-81.2
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	-14.6	-9.3	-82.5	8.8
Net impairment losses on available-for-sale securities	'	'	-64	-72.4
Net realized capital gains (losses)	-46.4	-50.9	41	-181.9
Total revenues	2,484.30	2,239.60	7,569.60	6,616.90
Expenses	'	'	'	'
Benefits, claims and settlement expenses	1,113.80	1,096.20	3,609.70	3,286.40
Dividends to policyholders	44.2	48.5	134.5	144.3
Operating expenses	932.5	774.6	2,647.70	2,372.10
Total expenses	2,090.50	1,919.30	6,391.90	5,802.80
Income (loss) before income taxes	393.8	320.3	1,177.70	814.1
Income taxes (benefits)	141	61.2	281.6	128.4
Net income (loss)	252.8	259.1	896.1	685.7
Net income (loss) attributable to noncontrolling interest	3.9	5.2	30.7	14.7
Net income (loss) attributable to Principal Financial Group, Inc.	248.9	253.9	865.4	671
Preferred stock dividends	8.2	8.2	24.7	24.7
Net income (loss) available to common stockholders	240.7	245.7	840.7	646.3
Net income (loss)	252.8	259.1	896.1	685.7
Other comprehensive income (loss)	-225.9	-18	190.1	-668.3
Comprehensive income (loss)	26.9	241.1	1,086.20	17.4
Principal Financial Group, Inc. Parent Only	'	'	'	'
Revenues	'	'	'	'
Net investment income (loss)	'	'	0.4	0.4
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	'	'	'	6.3
Net realized capital gains (losses)	'	'	'	6.3
Total revenues	'	'	0.4	6.7
Expenses	'	'	'	'
Operating expenses	'	'	106.8	105.2
Total expenses	'	'	106.8	105.2
Income (loss) before income taxes	'	'	-106.4	-98.5
Income taxes (benefits)	'	'	-42.7	-39.4
Equity in the net income (loss) of subsidiaries	'	'	929.1	730.1
Net income (loss)	'	'	865.4	671
Net income (loss) attributable to Principal Financial Group, Inc.	'	'	865.4	671
Preferred stock dividends	'	'	24.7	24.7
Net income (loss) available to common stockholders	'	'	840.7	646.3
Net income (loss)	'	'	865.4	671
Other comprehensive income (loss)	'	'	129.6	-683.9
Comprehensive income (loss)	'	'	995	-12.9
Principal Financial Services, Inc. Only	'	'	'	'
Revenues	'	'	'	'
Fees and other revenues	'	'	0.3	0.9
Net investment income (loss)	'	'	0.5	1.1
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	'	'	'	2.6
Net realized capital gains (losses)	'	'	'	2.6
Total revenues	'	'	0.8	4.6
Expenses	'	'	'	'
Operating expenses	'	'	3.1	8.4
Total expenses	'	'	3.1	8.4
Income (loss) before income taxes	'	'	-2.3	-3.8
Income taxes (benefits)	'	'	-3.2	-2.2
Equity in the net income (loss) of subsidiaries	'	'	928.2	731.7
Net income (loss)	'	'	929.1	730.1
Net income (loss) attributable to Principal Financial Group, Inc.	'	'	929.1	730.1
Net income (loss) available to common stockholders	'	'	929.1	730.1
Net income (loss)	'	'	929.1	730.1
Other comprehensive income (loss)	'	'	183.5	-671.8
Comprehensive income (loss)	'	'	1,112.60	58.3
Principal Life Insurance Company and Other Subsidiaries Combined	'	'	'	'
Revenues	'	'	'	'
Premiums and other considerations	'	'	2,514.80	2,134.90
Fees and other revenues	'	'	2,569.40	2,357.80
Net investment income (loss)	'	'	2,443.20	2,321.80
Net realized capital gains (losses), excluding impairment losses on available-for-sale securities	'	'	105	-118.4
Net other-than-temporary impairment (losses) recoveries on available-for-sale securities	'	'	18.5	-81.2
Other-than-temporary impairment losses on fixed maturities, available-for-sale reclassified to (from) other comprehensive income	'	'	-82.5	8.8
Net impairment losses on available-for-sale securities	'	'	-64	-72.4
Net realized capital gains (losses)	'	'	41	-190.8
Total revenues	'	'	7,568.40	6,623.70
Expenses	'	'	'	'
Benefits, claims and settlement expenses	'	'	3,609.70	3,286.40
Dividends to policyholders	'	'	134.5	144.3
Operating expenses	'	'	2,537.80	2,276.60
Total expenses	'	'	6,282	5,707.30
Income (loss) before income taxes	'	'	1,286.40	916.4
Income taxes (benefits)	'	'	327.5	170
Net income (loss)	'	'	958.9	746.4
Net income (loss) attributable to noncontrolling interest	'	'	30.7	14.7
Net income (loss) attributable to Principal Financial Group, Inc.	'	'	928.2	731.7
Net income (loss) available to common stockholders	'	'	928.2	731.7
Net income (loss)	'	'	958.9	746.4
Other comprehensive income (loss)	'	'	163.9	-679.2
Comprehensive income (loss)	'	'	1,122.80	67.2
Eliminations, Shelf Registration Debt Guarantor	'	'	'	'
Revenues	'	'	'	'
Fees and other revenues	'	'	'	-18.3
Net investment income (loss)	'	'	'	0.2
Total revenues	'	'	'	-18.1
Expenses	'	'	'	'
Operating expenses	'	'	'	-18.1
Total expenses	'	'	'	-18.1
Equity in the net income (loss) of subsidiaries	'	'	-1,857.30	-1,461.80
Net income (loss)	'	'	-1,857.30	-1,461.80
Net income (loss) attributable to Principal Financial Group, Inc.	'	'	-1,857.30	-1,461.80
Net income (loss) available to common stockholders	'	'	-1,857.30	-1,461.80
Net income (loss)	'	'	-1,857.30	-1,461.80
Other comprehensive income (loss)	'	'	-286.9	1,366.60
Comprehensive income (loss)	'	'	($2,144.20)	($95.20)

Condensed_Consolidating_Financ7

Condensed Consolidating Financial Information (Details 6) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Operating activities	'	'
Net cash provided by (used in) operating activities	$2,197.60	$1,397.90
Investing activities	'	'
Available-for-sale securities: Purchases	-6,596	-7,012.30
Available-for-sale securities: Sales	1,871.50	1,626.70
Available-for-sale securities: Maturities	4,499.30	5,783.20
Mortgage loans acquired or originated	-1,614.20	-2,020
Mortgage loans sold or repaid	1,319.80	1,570.80
Real estate acquired	-246.8	-59
Net (purchases) sales of property and equipment	-117.5	-22.7
Purchases of interest in subsidiaries, net of cash acquired	'	-1,268.30
Net change in other investments	56.6	-31.2
Net cash provided by (used in) investing activities	-827.3	-1,432.80
Financing activities	'	'
Issuance of common stock	69.6	80.2
Acquisition of treasury stock	-222.5	-153.4
Proceeds from financing element derivatives	14.9	46.7
Payments for financing element derivatives	-41.5	-36.9
Excess tax benefits from share-based payment arrangements	8.6	8.6
Purchase of subsidiary shares from noncontrolling interest	-222.4	-51.4
Sale of subsidiary shares to noncontrolling interest	'	31.8
Dividends to common stockholders	-276.7	-211.7
Dividends to preferred stockholders	-24.7	-24.7
Issuance of long-term debt	36.5	24.1
Principal repayments of long-term debt	-100.3	-212.2
Net proceeds from (repayments of) short-term borrowings	-20.5	131.6
Investment contract deposits	4,184.30	5,270.20
Investment contract withdrawals	-5,864.30	-7,055.60
Net increase (decrease) in banking operation deposits	-2.3	-276.2
Other	-10	-6.3
Net cash provided by (used in) financing activities	-2,471.30	-2,435.20
Net increase (decrease) in cash and cash equivalents	-1,101	-2,470.10
Cash and cash equivalents at beginning of period	2,371.80	4,177.20
Cash and cash equivalents at end of period	1,270.80	1,707.10
Principal Financial Group, Inc. Parent Only	'	'
Operating activities	'	'
Net cash provided by (used in) operating activities	-42.3	-12.8
Investing activities	'	'
Dividends and returns of capital received from (contributions to) unconsolidated entities	517.5	169.3
Net change in other investments	-2	-3.2
Net cash provided by (used in) investing activities	515.5	166.1
Financing activities	'	'
Issuance of common stock	69.6	80.2
Acquisition of treasury stock	-222.5	-153.4
Excess tax benefits from share-based payment arrangements	0.3	'
Dividends to common stockholders	-276.7	-211.7
Dividends to preferred stockholders	-24.7	-24.7
Net cash provided by (used in) financing activities	-454	-309.6
Net increase (decrease) in cash and cash equivalents	19.2	-156.3
Cash and cash equivalents at beginning of period	131.5	207.1
Cash and cash equivalents at end of period	150.7	50.8
Principal Financial Services, Inc. Only	'	'
Operating activities	'	'
Net cash provided by (used in) operating activities	-373.5	870.9
Investing activities	'	'
Dividends and returns of capital received from (contributions to) unconsolidated entities	714	-809.2
Net change in other investments	-98.7	-13.9
Net cash provided by (used in) investing activities	615.3	-823.1
Financing activities	'	'
Capital received from (dividends and capital paid to) parent	-517.5	-169.3
Net cash provided by (used in) financing activities	-517.5	-169.3
Net increase (decrease) in cash and cash equivalents	-275.7	-121.5
Cash and cash equivalents at beginning of period	688.7	612.5
Cash and cash equivalents at end of period	413	491
Principal Life Insurance Company and Other Subsidiaries Combined	'	'
Operating activities	'	'
Net cash provided by (used in) operating activities	2,335.40	1,473.40
Investing activities	'	'
Available-for-sale securities: Purchases	-6,596	-7,012.30
Available-for-sale securities: Sales	1,871.50	1,626.70
Available-for-sale securities: Maturities	4,499.30	5,783.20
Mortgage loans acquired or originated	-1,614.20	-2,020
Mortgage loans sold or repaid	1,319.80	1,570.80
Real estate acquired	-246.8	-59
Net (purchases) sales of property and equipment	-117.5	-22.7
Purchases of interest in subsidiaries, net of cash acquired	'	-1,268.30
Net change in other investments	185.2	-14.1
Net cash provided by (used in) investing activities	-698.7	-1,415.70
Financing activities	'	'
Proceeds from financing element derivatives	14.9	46.7
Payments for financing element derivatives	-41.5	-36.9
Excess tax benefits from share-based payment arrangements	8.3	8.6
Purchase of subsidiary shares from noncontrolling interest	-222.4	-51.4
Sale of subsidiary shares to noncontrolling interest	'	31.8
Issuance of long-term debt	36.5	1,108.40
Principal repayments of long-term debt	-100.3	-212.2
Net proceeds from (repayments of) short-term borrowings	-113.5	-2,113.20
Capital received from (dividends and capital paid to) parent	-714	809.2
Investment contract deposits	4,184.30	5,270.20
Investment contract withdrawals	-5,864.30	-7,055.60
Net increase (decrease) in banking operation deposits	-2.3	-276.2
Other	-10	-6.3
Net cash provided by (used in) financing activities	-2,824.30	-2,476.90
Net increase (decrease) in cash and cash equivalents	-1,187.60	-2,419.20
Cash and cash equivalents at beginning of period	2,384	4,241.30
Cash and cash equivalents at end of period	1,196.40	1,822.10
Eliminations, Shelf Registration Debt Guarantor	'	'
Operating activities	'	'
Net cash provided by (used in) operating activities	278	-933.6
Investing activities	'	'
Dividends and returns of capital received from (contributions to) unconsolidated entities	-1,231.50	639.9
Net change in other investments	-27.9	'
Net cash provided by (used in) investing activities	-1,259.40	639.9
Financing activities	'	'
Issuance of long-term debt	'	-1,084.30
Net proceeds from (repayments of) short-term borrowings	93	2,244.80
Capital received from (dividends and capital paid to) parent	1,231.50	-639.9
Net cash provided by (used in) financing activities	1,324.50	520.6
Net increase (decrease) in cash and cash equivalents	343.1	226.9
Cash and cash equivalents at beginning of period	-832.4	-883.7
Cash and cash equivalents at end of period	($489.30)	($656.80)