Elevance Health (ELV) 10-Q 29 Jul 15 2015 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 15, 2015
Document and Entity Information
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Trading Symbol	ANTM
Entity Registrant Name	Anthem, Inc.
Entity Central Index Key	1,156,039
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	261,575,584	261,587,142

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 1,553	$ 2,151.7
Investments available-for-sale, at fair value:
Fixed maturity securities (amortized cost of $18,021.7 and $17,120.4)	18,236.5	17,467.4
Equity securities (cost of $1,236.7 and $1,303.7)	1,705.4	1,906.6
Other invested assets, current	23.4	20.2
Accrued investment income	168.6	161.4
Premium and self-funded receivables	4,940.8	4,825.5
Other receivables	2,368	2,117
Income taxes receivable	13.8	308.9
Securities lending collateral	1,718.3	1,515.2
Deferred tax assets, net	295.6	280.4
Other current assets	2,178.8	1,473.9
Total current assets	33,202.2	32,228.2
Long-term investments available-for-sale, at fair value:
Fixed maturity securities (amortized cost of $613.5 and $500.7)	613.7	504.4
Equity securities (cost of $27.3 and $27.0)	31.7	31.5
Other invested assets, long-term	1,803.3	1,695.9
Property and equipment, net	1,931.4	1,944.3
Goodwill	17,541.7	17,082
Other intangible assets	8,275.5	7,958.1
Other noncurrent assets	864.3	512.3
Total assets	64,263.8	61,956.7
Liabilities and shareholders' equity
Medical claims payable	7,177.9	6,861.2
Reserves for future policy benefits	67.7	68.1
Other policyholder liabilities	2,741.4	2,626.5
Total policy liabilities	9,987	9,555.8
Unearned income	950.5	1,078.1
Accounts payable and accrued expenses	4,433.8	3,651.8
Security trades pending payable	172.5	66.2
Securities lending payable	1,718.2	1,515.3
Short-term borrowings	540	400
Current portion of long-term debt	624.9	624.3
Other current liabilities	2,246.3	1,861.2
Total current liabilities	20,673.2	18,752.7
Long-term debt, less current portion	15,468.4	14,019.6
Reserves for future policy benefits, noncurrent	607.6	671.3
Deferred tax liabilities, net	3,226.2	3,226
Other noncurrent liabilities	1,225.8	1,035.8
Total liabilities	$ 41,201.2	$ 37,705.4
Commitment and contingencies – Note 10
Shareholders' equity
Preferred stock, without par value, shares authorized – 100,000,000; shares issued and outstanding – none	$ 0	$ 0
Common stock, par value $0.01, shares authorized – 900,000,000; shares issued and outstanding – 261,575,584 and 268,109,932	2.6	2.7
Additional paid-in capital	8,707.4	10,062.3
Retained earnings	14,352.2	14,014.4
Accumulated other comprehensive income	0.4	171.9
Total shareholders' equity	23,062.6	24,251.3
Total liabilities and shareholders' equity	$ 64,263.8	$ 61,956.7

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Available-for-sale fixed maturity securities investments, current, amortized cost	$ 18,021.7	$ 17,120.4
Available-for-sale equity securities investments, current, cost	1,236.7	1,303.7
Available-for-sale fixed maturity securities investments, long-term, amortized cost	613.5	500.7
Available-for-sale equity securities investments, long-term, cost	$ 27.3	$ 27
Preferred stock, par value	$ 0	$ 0
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	900,000,000	900,000,000
Common stock, shares issued	261,575,584	268,109,932
Common stock, shares outstanding	261,575,584	268,109,932

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues
Premiums	$ 18,516.3	$ 17,068.9	$ 36,126.8	$ 33,585.9
Administrative fees	1,229.5	1,151.6	2,456.6	2,269.9
Other revenue	12.5	9.5	26.3	19
Total operating revenue	19,758.3	18,230	38,609.7	35,874.8
Net investment income	186.7	188.5	354.3	372.2
Net realized gains on investments	92.3	65.8	138.8	107.5
Other-than-temporary impairment losses on investments:
Total other-than-temporary impairment losses on investments	(26.2)	(11.7)	(41.6)	(22.5)
Portion of other-than-temporary impairment losses recognized in other comprehensive income	4.4	0.8	5.8	0.8
Other-than-temporary impairment losses recognized in income	(21.8)	(10.9)	(35.8)	(21.7)
Total revenues	20,015.5	18,473.4	39,067	36,332.8
Expenses
Benefit expense	15,205.4	14,121.3	29,332.3	27,785.9
Selling, general and administrative expense:
Selling expense	363.8	388.7	732	759.5
General and administrative expense	2,677	2,497.1	5,454	4,987.8
Total selling, general and administrative expense	3,040.8	2,885.8	6,186	5,747.3
Interest expense	154.1	145.6	308.5	291.8
Amortization of other intangible assets	60.1	54	112.6	108
(Gain) loss on extinguishment of debt	(2.9)	3	0.5	6
Total expenses	18,457.5	17,209.7	35,939.9	33,939
Income from continuing operations before income tax expense	1,558	1,263.7	3,127.1	2,393.8
Income tax expense	698.9	532.6	1,402.8	971.3
Income from continuing operations	859.1	731.1	1,724.3	1,422.5
Income from discontinued operations, net of tax	0	0	0	9.6
Net income	$ 859.1	$ 731.1	$ 1,724.3	$ 1,432.1
Net income per share
Basic - continuing operations (in dollars per share)	$ 3.27	$ 2.64	$ 6.51	$ 5.07
Basic - discontinued operations (in dollars per share)	0	0	0	0.03
Basic net income per share	3.27	2.64	6.51	5.10
Diluted - continuing operations (in dollars per share)	3.13	2.56	6.22	4.92
Diluted - discontinued operations (in dollars per share)	0	0	0	0.03
Diluted net income per share	3.13	2.56	6.22	4.95
Dividends per share	$ 0.6250	$ 0.4375	$ 1.2500	$ 0.8750

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 859.1	$ 731.1	$ 1,724.3	$ 1,432.1
Other comprehensive (loss) income, net of tax:
Change in net unrealized gains/losses on investments	(241.2)	144.6	(180.8)	284.9
Change in non-credit component of other-than-temporary impairment losses on investments	(2.8)	(0.5)	0.7	0
Change in net unrealized gains/losses on cash flow hedges	0.9	0.8	1.8	1.5
Change in net periodic pension and postretirement costs	4.9	3	9.6	5.9
Foreign currency translation adjustments	0.7	(0.3)	(2.8)	(0.5)
Other comprehensive (loss) income	(237.5)	147.6	(171.5)	291.8
Total comprehensive income	$ 621.6	$ 878.7	$ 1,552.8	$ 1,723.9

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating activities
Net income	$ 1,724.3	$ 1,432.1
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized gains on investments	(138.8)	(107.5)
Other-than-temporary impairment losses recognized in income	35.8	21.7
Loss on extinguishment of debt	0.5	6
Gain on disposal from discontinued operations	0	(3.2)
Loss on disposal of assets	1.2	0.7
Deferred income taxes	47.5	48.7
Amortization, net of accretion	655.5	381.4
Depreciation expense	50.3	53.4
Impairment of property and equipment	0	2.2
Share-based compensation	68.6	88.9
Excess tax benefits from share-based compensation	(89)	(29.3)
Changes in operating assets and liabilities:
Receivables, net	(318.5)	(839)
Other invested assets	(4)	(23.6)
Other assets	(388.9)	(108.3)
Policy liabilities	278.8	853.2
Unearned income	(161.1)	130.5
Accounts payable and accrued expenses	231.1	213
Other liabilities	488.1	211.5
Income taxes	347.9	179.8
Other, net	(5.8)	(53.7)
Net cash provided by operating activities	2,823.5	2,458.5
Investing activities
Purchases of fixed maturity securities	(5,530.6)	(5,493.1)
Proceeds from fixed maturity securities:
Sales	4,371.6	4,024.8
Maturities, calls and redemptions	664.9	645.6
Purchases of equity securities	(1,389.5)	(359.3)
Proceeds from sales of equity securities	1,085.9	255.2
Purchases of other invested assets	(161.1)	(81.9)
Proceeds from sales of other invested assets	38.3	35.8
Settlement of non-hedging derivatives	(32)	(46.2)
Changes in securities lending collateral	(202.9)	(976.9)
Purchase of subsidiary, net of cash acquired	(641.6)	0
Proceeds from sale of subsidiary, net of cash sold	0	740
Purchases of property and equipment	(229.7)	(271.2)
Other, net	0	(0.1)
Net cash used in investing activities	(2,026.7)	(1,527.3)
Financing activities
Net proceeds from commercial paper borrowings	697.4	487.9
Proceeds from issuance of long-term debt	1,228.7	0
Repayments of long-term borrowings	(1,930)	(45.1)
Proceeds from short-term borrowings	2,120	1,650
Repayments of short-term borrowings	(1,980)	(1,800)
Changes in securities lending payable	202.9	977
Changes in bank overdrafts	(233.1)	106.8
Premiums paid on equity call options	(16.6)	0
Proceeds from equity put options	16.5	0
Repurchase and retirement of common stock	(1,410.6)	(2,077.2)
Cash dividends	(330.5)	(243.9)
Proceeds from issuance of common stock under employee stock plans	155.2	182.5
Excess tax benefits from share-based compensation	89	29.3
Net cash used in financing activities	(1,391.1)	(732.7)
Effect of foreign exchange rates on cash and cash equivalents	(4.4)	(0.8)
Change in cash and cash equivalents	(598.7)	197.7
Cash and cash equivalents, at beginning of period	2,151.7	1,586.9
Cash and cash equivalents, at end of period	1,553	$ 1,784.6
Cash and cash equivalents of continuing operations at end of period	$ 1,553

Consolidated Statements Of Shar

Consolidated Statements Of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Balance at Dec. 31, 2013	$ 24,765.2	$ 2.9	$ 10,765.2	$ 13,813.9	$ 183.2
Balance (in shares) at Dec. 31, 2013		293.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,432.1			1,432.1
Other comprehensive income (loss)	291.8				291.8
Settlement of equity options	$ (19.4)		(19.4)
Repurchase and retirement of common stock, shares	(22.6)	(22.6)
Repurchase and retirement of common stock, value	$ (2,077.2)	$ (0.2)	(822.1)	(1,254.9)
Dividends and dividend equivalents	(246.7)			(246.7)
Issuance of common stock under employee stock plans, net of related tax benefits, Shares		3.8
Issuance of common stock under employee stock plans, net of related tax benefits	231.1	$ 0	231.1
Balance at Jun. 30, 2014	24,376.9	$ 2.7	10,154.8	13,744.4	475
Balance (in shares) at Jun. 30, 2014		274.5
Balance at Dec. 31, 2014	24,251.3	$ 2.7	10,062.3	14,014.4	171.9
Balance (in shares) at Dec. 31, 2014		268.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,724.3			1,724.3
Other comprehensive income (loss)	(171.5)				(171.5)
Premiums for equity options	$ (16.6)		(16.6)
Repurchase and retirement of common stock, shares	(9.7)	(9.7)
Repurchase and retirement of common stock, value	$ (1,410.6)	$ (0.1)	(357.7)	(1,052.8)
Dividends and dividend equivalents	(333.7)			(333.7)
Issuance of common stock under employee stock plans, net of related tax benefits, Shares		3.2
Issuance of common stock under employee stock plans, net of related tax benefits	193.9		193.9
Convertible debenture repurchases and conversions	(1,043.6)		(1,043.6)
Equity Units contract payments and issuance costs	(130.9)		(130.9)
Balance at Jun. 30, 2015	$ 23,062.6	$ 2.6	$ 8,707.4	$ 14,352.2	$ 0.4
Balance (in shares) at Jun. 30, 2015		261.6

Organization

Organization	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization References to the terms “we”, “our”, “us”, “Anthem” or the “Company” used throughout these Notes to Consolidated Financial Statements refer to Anthem, Inc., an Indiana corporation, and unless the context otherwise requires, its direct and indirect subsidiaries. We are one of the largest health benefits companies in terms of medical membership in the United States, serving 38.5 medical members through our affiliated health plans as of June 30, 2015 . We offer a broad spectrum of network-based managed care plans to large and small employer, individual, Medicaid and Medicare markets. Our managed care plans include: preferred provider organizations, or PPOs; health maintenance organizations, or HMOs; point-of-service, or POS, plans; traditional indemnity plans and other hybrid plans, including consumer-driven health plans, or CDHPs; and hospital only and limited benefit products. In addition, we provide a broad array of managed care services to self-funded customers, including claims processing, underwriting, stop loss insurance, actuarial services, provider network access, medical cost management, disease management, wellness programs and other administrative services. We provide an array of specialty and other insurance products and services such as dental, vision, life and disability insurance benefits, radiology benefit management and analytics-driven personal health care. We also provide services to the federal government in connection with the Federal Employee Program, or FEP. We also sold contact lenses, eyeglasses and other ocular products through our 1-800 CONTACTS, Inc., or 1-800 CONTACTS, business, which was divested on January 31, 2014. We are an independent licensee of the Blue Cross and Blue Shield Association, or BCBSA, an association of independent health benefit plans. We serve our members as the Blue Cross licensee for California and as the Blue Cross and Blue Shield, or BCBS, licensee for Colorado, Connecticut, Georgia, Indiana, Kentucky, Maine, Missouri (excluding 30 counties in the Kansas City area), Nevada, New Hampshire, New York (as BCBS in 10 New York City metropolitan and surrounding counties, and as Blue Cross or BCBS in selected upstate counties only), Ohio, Virginia (excluding the Northern Virginia suburbs of Washington, D.C.) and Wisconsin. In a majority of these service areas we do business as Anthem Blue Cross, Anthem Blue Cross and Blue Shield, Blue Cross and Blue Shield of Georgia, and Empire Blue Cross Blue Shield, or Empire Blue Cross (in our New York service areas). We also conduct business through arrangements with other BCBS licensees in the states of South Carolina and Texas. We conduct business through our AMERIGROUP Corporation, or Amerigroup, subsidiary, in Florida, Georgia, Kansas, Louisiana, Maryland, Nevada, New Jersey, New Mexico, New York, Tennessee, Texas and Washington. We conduct business through our recently acquired Simply Healthcare Holdings, Inc., or Simply Healthcare, subsidiary in the state of Florida. We also serve customers throughout the country as HealthLink, UniCare (including a non-risk arrangement with the state of Massachusetts), and in certain Arizona, California, Nevada, New York and Virginia markets through our CareMore Health Group, Inc., or CareMore, subsidiary. We are licensed to conduct insurance operations in all 50 states through our subsidiaries.

Subsequent Event (Notes)

Subsequent Event (Notes)	6 Months Ended
	Jun. 30, 2015
Subsequent Event [Abstract]
Subsequent Event [Text Block]	Subsequent Event On July 24, 2015, we and Cigna Corporation, or Cigna, announced that we entered into an Agreement and Plan of Merger, or Merger Agreement, dated as of July 23, 2015, by and among Anthem, Cigna and Anthem Merger Sub Corp., a Delaware corporation and a direct wholly-owned subsidiary of Anthem, pursuant to which Anthem will acquire all outstanding shares of Cigna, or the Acquisition. This Acquisition will further our goal of creating a premier health benefits company with critical diversification and scale to lead the transformation of health care delivery for consumers. Cigna is a global health services organization that delivers affordable and personalized products and services to customers through employer-based, government-sponsored and individual coverage arrangements. All products and services are provided exclusively by or through operating subsidiaries of Cigna, including Connecticut General Life Insurance Company, Cigna Health and Life Insurance Company, Life Insurance Company of North America and Cigna Life Insurance Company of New York. Such products and services include an integrated suite of health services, such as medical, dental, behavioral health, pharmacy, vision, supplemental benefits, and other related products including group life, accident and disability insurance. Cigna maintains sales capability in 30 countries and jurisdictions. Under the terms of the Merger Agreement, Cigna’s stockholders will receive $103.40 in cash and 0.5152 shares of our common stock for each Cigna common share outstanding. The value of the transaction is estimated to be approximately $53,000.0 based on the closing price of our common stock on the New York Stock Exchange on July 23, 2015. The final purchase price will be determined based on our closing stock price on the date of closing of the Acquisition. The combined company will reflect a pro forma equity ownership comprised of approximately 67% Anthem stockholders and approximately 33% Cigna stockholders. We expect to finance the cash portion of the Acquisition through available cash on hand and the issuance of new debt. In addition, we entered into a bridge facility commitment letter which will provide up to $26,500.0 under a 364-day senior unsecured bridge term loan credit facility to finance the Acquisition in the event that we have not received any combination of (i) senior unsecured term loans, (ii) common or preferred equity or equity-linked securities and/or (iii) senior unsecured notes in a public offering or private placement in an aggregate principal amount of at least $26,500.0 prior to the consummation of the Acquisition. The Acquisition is expected to close in the second half of 2016 and is subject to certain state regulatory approvals, standard closing conditions, customary approvals required under the Hart-Scott-Rodino Antitrust Improvements Act and the approval of both our shareholders and Cigna’s stockholders.

Basis Of Presentation and Signi

Basis Of Presentation and Significant Accounting Policies	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies Basis of Presentation: The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial reporting. Accordingly, they do not include all of the information and footnotes required by GAAP for annual financial statements. We have omitted certain footnote disclosures that would substantially duplicate the disclosures in our 2014 Annual Report on Form 10-K, unless the information contained in those disclosures materially changed or is required by GAAP. Unless otherwise specified, all financial information presented in the accompanying consolidated financial statements and in the notes to consolidated financial statements relates only to our continuing operations, other than cash flows presented on the consolidated statements of cash flows. In the opinion of management, all adjustments, including normal recurring adjustments, necessary for a fair statement of the consolidated financial statements as of and for the three and six months ended June 30, 2015 and 2014 have been recorded. The results of operations for the three and six months ended June 30, 2015 are not necessarily indicative of the results that may be expected for the full year ending December 31, 2015 . These unaudited consolidated financial statements should be read in conjunction with our audited consolidated financial statements for the year ended December 31, 2014 included in our 2014 Annual Report on Form 10-K. Certain of our subsidiaries operate outside of the United States and have functional currencies other than the U.S. dollar, or USD. We translate the assets and liabilities of those subsidiaries to USD using the exchange rate in effect at the end of the period. We translate the revenues and expenses of those subsidiaries to USD using the average exchange rates in effect during the period. The net effect of these translation adjustments is included in “Foreign currency translation adjustments” in our consolidated statements of comprehensive income. Recently Adopted Accounting Guidance: In June 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update No. 2014-11, Transfers and Servicing (Topic 860): Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures, or ASU 2014-11 . This amendment requires repurchase-to-maturity transactions to be accounted for as secured borrowings and eliminates previous guidance for repurchase financings. The amendment also expands the disclosure requirements related to certain transactions accounted for as secured borrowings and certain transfers accounted for as sales when the transferor also retains substantially all of the exposure to the economic return on the transferred financial assets throughout the term of the transaction. The amendments related to the accounting of, and disclosure requirements for, certain transactions accounted for as a sale became effective as of January 1, 2015 and did not have an impact on our consolidated financial position, results of operations, cash flows or disclosures. The new disclosure requirements for repurchase agreements, securities lending transactions and repurchase-to-maturity transactions accounted for as secured borrowings became effective as of April 1, 2015. See Note 5, "Investments - Securities Lending Programs, " for additional disclosure information related to the adoption of ASU 2014-11. In April 2015, the FASB issued Accounting Standards Update No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs , or ASU 2015-03. ASU 2015-03 amends current presentation guidance by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. Prior to the issuance of ASU 2015-03, debt issuance costs were required to be presented as an asset in the balance sheet. We adopted the provisions of ASU 2015-03 upon issuance and prior period amounts have been reclassified to conform to the current period presentation. As of December 31, 2014, $0.7 of debt issuance costs were reclassified in the consolidated balance sheet from other current assets to current portion of long-term debt and $ 107.6 was reclassified from other noncurrent assets to long-term debt, less current portion. The adoption of ASU 2015-03 did not impact our consolidated financial position, results of operations or cash flows. Recent Accounting Guidance Not Yet Adopted: In May 2015, the FASB issued Accounting Standards Update No. 2015-09, Financial Services—Insurance (Topic 944): Disclosures about Short-Duration Contracts, or ASU 2015-09. This amendment requires new and expanded disclosures in interim and annual reporting periods related to the liability for unpaid claims and claim adjustment expenses for short-duration insurance contracts. ASU 2015-09 is effective for annual reporting periods beginning after December 15, 2015, and interim reporting periods within annual reporting periods beginning after December 15, 2016. The adoption of ASU 2015-03 will not impact our consolidated financial position, results of operations or cash flows. In April 2015, the FASB issued Accounting Standards Update No. 2015-05, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement , or ASU 2015-05. This amendment provides guidance to help entities determine whether a cloud computing arrangement contains a software license that should be accounted for as internal-use software or as a service contract. ASU 2015-05 is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted. Upon adoption, an entity has the option to apply the provisions of ASU 2015-05 either prospectively to all arrangements entered into or materially modified, or retrospectively. We are currently evaluating the effects the adoption of ASU 2015-05 will have upon our consolidated financial position, results of operations or cash flows. In February 2015, the FASB issued Accounting Standards Update No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis , or ASU 2015-02. ASU 2015-02 amends current consolidation guidance by modifying the evaluation of whether limited partnerships and similar legal entities are variable interest entities or voting interest entities, eliminating the presumption that a general partner should consolidate a limited partnership, and affects the consolidation analysis of reporting entities that are involved with variable interest entities. ASU No. 2015-02 is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted. All legal entities are subject to reevaluation under the revised consolidation model. The adoption of ASU 2015-02 is not expected to have a material impact on our consolidated financial position, results of operations or cash flows. There were no other new accounting pronouncements that were issued or became effective since the issuance of our 2014 Annual Report on Form 10-K that had, or are expected to have, a material impact on our consolidated financial position, results of operations or cash flows.

Business Acquisition and Divest

Business Acquisition and Divestiture	6 Months Ended
	Jun. 30, 2015
Business Combinations [Abstract]
Business Acquisition and Divestiture	Business Acquisition and Divestiture Simply Healthcare On February 17, 2015, we completed our acquisition of Simply Healthcare, a leading managed care company for people enrolled in Medicaid and Medicare programs in the state of Florida. This acquisition aligns with our strategy for continued growth in our Government Business segment. In accordance with FASB accounting guidance for business combinations, the preliminary consideration transferred was allocated to the fair value of Simply Healthcare's assets acquired and liabilities assumed, including identifiable intangible assets. The excess of the consideration transferred over the fair value of net assets acquired resulted in preliminary non-tax-deductible goodwill of $459.7 at June 30, 2015, all of which was allocated to our Government Business segment. Preliminary goodwill recognized from the acquisition of Simply Healthcare primarily relates to the future economic benefits arising from the assets acquired and is consistent with our stated intentions to strengthen our position and expand operations in the government sector to service Medicaid and Medicare enrollees. Any additional payments or receipts of cash resulting from contractual purchase price adjustments or any subsequent adjustments made to the assets acquired and liabilities assumed during the measurement period will be recorded as an adjustment to goodwill. The preliminary fair value of the net assets acquired from Simply Healthcare includes $430.0 of other intangible assets, which primarily consist of indefinite-lived state licenses and finite-lived customer relationships with amortization periods ranging from 2 to 4 years. The results of operations of Simply Healthcare are included in our consolidated financial statements within our Government Business segment for the period following February 17, 2015. The pro-forma effects of this acquisition for prior periods were not material to our consolidated results of operations. 1-800 CONTACTS In December 2013, we entered into a definitive agreement to sell our 1-800 CONTACTS business to the private equity firm Thomas H. Lee Partners, L.P. Additionally, we entered into an asset purchase agreement with Luxottica Group to sell our glasses.com related assets (collectively, 1-800 CONTACTS). The sales were completed on January 31, 2014 and did not result in any material difference to the loss on disposal from discontinued operations recorded during the year ended December 31, 2013. The operating results for 1-800 CONTACTS for the one month ended January 31, 2014 are reported as discontinued operations in the accompanying consolidated statements of income. The operating results for 1-800 CONTACTS were previously reported in our Commercial and Specialty Business segment.

Investments

Investments	6 Months Ended
	Jun. 30, 2015
Investments [Abstract]
Investments	Investments We evaluate our investment securities for other-than-temporary declines based on qualitative and quantitative factors. Other-than-temporary impairment losses recognized in income totaled $21.8 and $10.9 for the three months ended June 30, 2015 and 2014 , respectively. Other-than-temporary impairment losses recognized in income totaled $35.8 and $21.7 for the six months ended June 30, 2015 and 2014 , respectively. There were no individually significant other-than-temporary impairment losses on investments by issuer during the three and six months ended June 30, 2015 and 2014 . We continue to review our investment portfolios under our impairment review policy. Given the inherent uncertainty of changes in market conditions and the significant judgments involved, there is a continuing risk that further declines in fair value may occur and additional material other-than-temporary impairment losses on investments may be recorded in future periods. A summary of current and long-term investments, available-for-sale, at June 30, 2015 and December 31, 2014 is as follows: Non-Credit Component of Other-Than- Cost or Gross Gross Unrealized Losses Estimated Less than 12 Months 12 Months or Greater June 30, 2015 Fixed maturity securities: United States Government securities $ 323.9 $ 2.8 $ (0.8 ) $ — $ 325.9 $ — Government sponsored securities 87.7 0.8 (0.1 ) (0.2 ) 88.2 — States, municipalities and political subdivisions, tax-exempt 5,782.6 212.2 (24.8 ) (5.2 ) 5,964.8 — Corporate securities 9,380.6 119.8 (112.0 ) (23.2 ) 9,365.2 (5.8 ) Options embedded in convertible debt securities 0.8 — — — 0.8 — Residential mortgage-backed securities 1,895.2 52.4 (7.1 ) (7.5 ) 1,933.0 — Commercial mortgage-backed securities 432.3 4.0 (1.1 ) (0.2 ) 435.0 — Other debt securities 732.1 7.2 (0.9 ) (1.1 ) 737.3 — Total fixed maturity securities 18,635.2 399.2 (146.8 ) (37.4 ) 18,850.2 $ (5.8 ) Equity securities 1,264.0 495.9 (22.8 ) — 1,737.1 Total investments, available-for-sale $ 19,899.2 $ 895.1 $ (169.6 ) $ (37.4 ) $ 20,587.3 December 31, 2014 Fixed maturity securities: United States Government securities $ 315.7 $ 4.6 $ (0.3 ) $ — $ 320.0 $ — Government sponsored securities 94.6 0.8 — (0.4 ) 95.0 — States, municipalities and political subdivisions, tax-exempt 5,451.4 287.0 (1.8 ) (3.0 ) 5,733.6 — Corporate securities 8,335.9 162.9 (123.1 ) (43.2 ) 8,332.5 (6.8 ) Options embedded in convertible debt securities 98.7 — — — 98.7 — Residential mortgage-backed securities 2,099.7 68.9 (1.0 ) (8.6 ) 2,159.0 — Commercial mortgage-backed securities 504.8 6.1 (0.6 ) (0.4 ) 509.9 — Other debt securities 720.3 6.1 (1.7 ) (1.6 ) 723.1 — Total fixed maturity securities 17,621.1 536.4 (128.5 ) (57.2 ) 17,971.8 $ (6.8 ) Equity securities 1,330.7 618.5 (11.1 ) — 1,938.1 Total investments, available-for-sale $ 18,951.8 $ 1,154.9 $ (139.6 ) $ (57.2 ) $ 19,909.9 At June 30, 2015 , we owned $2,368.0 of mortgage-backed securities and $655.4 of asset-backed securities out of a total available-for-sale investment portfolio of $20,587.3 . These securities included sub-prime and Alt-A securities with fair values of $34.1 and $69.4 , respectively. These sub-prime and Alt-A securities had accumulated net unrealized gains of $1.2 and $4.6 , respectively. The average credit rating of the sub-prime and Alt-A securities was “CCC” and “CC”, respectively. The following tables summarize for available-for-sale fixed maturity securities and available-for-sale equity securities in an unrealized loss position at June 30, 2015 and December 31, 2014 , the aggregate fair value and gross unrealized loss by length of time those securities have been continuously in an unrealized loss position: Less than 12 Months 12 Months or Greater (Securities are whole amounts) Number of Securities Estimated Fair Value Gross Unrealized Loss Number of Securities Estimated Fair Value Gross Unrealized Loss June 30, 2015 Fixed maturity securities: United States Government securities 18 $ 69.1 $ (0.8 ) 2 $ 0.9 $ — Government sponsored securities 12 19.0 (0.1 ) 10 20.7 (0.2 ) States, municipalities and political subdivisions, tax-exempt 557 1,502.7 (24.8 ) 39 71.1 (5.2 ) Corporate securities 1,895 4,702.7 (112.0 ) 277 397.0 (23.2 ) Residential mortgage-backed securities 277 573.7 (7.1 ) 114 195.2 (7.5 ) Commercial mortgage-backed securities 49 135.8 (1.1 ) 13 28.0 (0.2 ) Other debt securities 56 183.7 (0.9 ) 21 56.8 (1.1 ) Total fixed maturity securities 2,864 7,186.7 (146.8 ) 476 769.7 (37.4 ) Equity securities 554 360.5 (22.8 ) — — — Total fixed maturity and equity securities 3,418 $ 7,547.2 $ (169.6 ) 476 $ 769.7 $ (37.4 ) December 31, 2014 Fixed maturity securities: United States Government securities 17 $ 145.3 $ (0.3 ) 2 $ 0.9 $ — Government sponsored securities 2 0.3 — 16 29.3 (0.4 ) States, municipalities and political subdivisions, tax-exempt 136 315.6 (1.8 ) 80 174.3 (3.0 ) Corporate securities 1,802 3,213.3 (123.1 ) 314 514.6 (43.2 ) Residential mortgage-backed securities 78 155.0 (1.0 ) 186 398.3 (8.6 ) Commercial mortgage-backed securities 43 156.2 (0.6 ) 10 33.2 (0.4 ) Other debt securities 79 270.6 (1.7 ) 21 65.0 (1.6 ) Total fixed maturity securities 2,157 4,256.3 (128.5 ) 629 1,215.6 (57.2 ) Equity securities 407 125.4 (11.1 ) — — — Total fixed maturity and equity securities 2,564 $ 4,381.7 $ (139.6 ) 629 $ 1,215.6 $ (57.2 ) The amortized cost and fair value of available-for-sale fixed maturity securities at June 30, 2015 , by contractual maturity, are shown below. Expected maturities may differ from contractual maturities because the issuers of the securities may have the right to prepay obligations. Amortized Cost Estimated Fair Value Due in one year or less $ 425.4 $ 428.2 Due after one year through five years 4,691.9 4,740.8 Due after five years through ten years 5,427.2 5,510.2 Due after ten years 5,763.2 5,803.0 Mortgage-backed securities 2,327.5 2,368.0 Total available-for-sale fixed maturity securities $ 18,635.2 $ 18,850.2 Proceeds from fixed maturity securities, equity securities and other invested assets and the related gross realized gains and gross realized losses for the three and six months ended June 30, 2015 and 2014 are as follows: Three Months Ended Six Months Ended 2015 2014 2015 2014 Proceeds $ 3,234.8 $ 2,560.0 $ 6,160.7 $ 4,961.4 Gross realized gains 148.4 106.2 282.1 189.1 Gross realized losses (56.1 ) (40.4 ) (143.3 ) (81.6 ) In the ordinary course of business, we may sell securities at a loss for a number of reasons, including, but not limited to: (i) changes in the investment environment; (ii) expectation that the fair value could deteriorate further; (iii) desire to reduce exposure to an issuer or an industry; (iv) changes in credit quality; or (v) changes in expected cash flow. All securities sold resulting in investment gains and losses are recorded on the trade date. Realized gains and losses are determined on the basis of the cost or amortized cost of the specific securities sold. Securities Lending Programs We participate in securities lending programs whereby marketable securities in our investment portfolio are transferred to independent brokers or dealers in exchange for cash and securities collateral. The fair value of the collateral received at the time of the transactions amounted to $1,718.2 and $1,515.3 at June 30, 2015 and December 31, 2014 , respectively. The value of the collateral represented 103% of the market value of the securities on loan at June 30, 2015 and December 31, 2014 . Under FASB guidance related to accounting for transfers and servicing of financial assets and extinguishments of liabilities, we recognize the collateral as an asset, which is reported as “Securities lending collateral” on our consolidated balance sheets and we record a corresponding liability for the obligation to return the collateral to the borrower, which is reported as “Securities lending payable.” The securities on loan are reported in the applicable investment category on our consolidated balance sheets. Unrealized gains or losses on securities lending collateral are included in accumulated other comprehensive income as a separate component of shareholders’ equity. The remaining contractual maturity of our securities lending agreements at June 30, 2015 is as follows: Overnight and Continuous Less than 30 days 30-90 days Greater Than 90 days Total Securities lending transactions United States Government securities $ 100.3 $ — $ 14.2 $ 57.4 $ 171.9 Corporate securities 747.2 — — — 747.2 Equity securities 418.7 — — — 418.7 Other debt securities 380.4 — — — 380.4 Total $ 1,646.6 $ — $ 14.2 $ 57.4 $ 1,718.2 The market value of loaned securities and that of the collateral pledged can fluctuate in non-synchronized fashions. To the extent the loaned securities' value appreciates faster or depreciates slower than the value of the collateral pledged, we are exposed to the risk of the shortfall. As a primary mitigating mechanism, the loaned securities and collateral pledged are marked to market on a daily basis and the shortfall, if any, is collected accordingly. Secondarily, the collateral level is set at 102% of the value of the loaned securities, which provides a cushion before any shortfall arises. The investment of the cash collateral is subject to market risk, which is managed by limiting the investments to higher quality and shorter duration instruments.

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value	Fair Value Assets and liabilities recorded at fair value in the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Level inputs, as defined by FASB guidance for fair value measurements and disclosures, are as follows: Level Input Input Definition Level I Inputs are unadjusted, quoted prices for identical assets or liabilities in active markets at the measurement date. Level II Inputs other than quoted prices included in Level I that are observable for the asset or liability through corroboration with market data at the measurement date. Level III Unobservable inputs that reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. The following methods, assumptions and inputs were used to determine the fair value of each class of the following assets and liabilities recorded at fair value in the consolidated balance sheets: Cash equivalents: Cash equivalents primarily consist of highly rated money market funds with maturities of three months or less and are purchased daily at par value with specified yield rates. Due to the high ratings and short-term nature of the funds, we designate all cash equivalents as Level I. Fixed maturity securities, available-for-sale: Fair values of available-for-sale fixed maturity securities are based on quoted market prices, where available. These fair values are obtained primarily from third party pricing services, which generally use Level I or Level II inputs for the determination of fair value to facilitate fair value measurements and disclosures. United States Government securities represent Level I securities, while Level II securities primarily include corporate securities, securities from states, municipalities and political subdivisions and mortgage-backed securities. For securities not actively traded, the pricing services may use quoted market prices of comparable instruments or discounted cash flow analyses, incorporating inputs that are currently observable in the markets for similar securities. We have controls in place to review the pricing services’ qualifications and procedures used to determine fair values. In addition, we periodically review the pricing services’ pricing methodologies, data sources and pricing inputs to ensure the fair values obtained are reasonable. Inputs that are often used in the valuation methodologies include, but are not limited to, broker quotes, benchmark yields, credit spreads, default rates and prepayment speeds. We also have certain fixed maturity securities, primarily corporate debt securities, that are designated Level III securities. For these securities, the valuation methodologies may incorporate broker quotes or discounted cash flow analyses using assumptions for inputs such as expected cash flows, benchmark yields, credit spreads, default rates and prepayment speeds that are not observable in the markets. Equity securities, available-for-sale: Fair values of equity securities are generally designated as Level I and are based on quoted market prices. For certain equity securities, quoted market prices for the identical security are not always available and the fair value is estimated by reference to similar securities for which quoted prices are available. These securities are designated Level II. We also have certain equity securities, including private equity securities, for which the fair value is estimated based on each security’s current condition and future cash flow projections. Such securities are designated Level III. The fair values of these private equity securities are generally based on either broker quotes or discounted cash flow projections using assumptions for inputs such as the weighted-average cost of capital, long-term revenue growth rates and earnings before interest, taxes, depreciation and amortization, or EBITDA, and/or revenue multiples that are not observable in the markets. Other invested assets, current: Other invested assets, current include securities held in rabbi trusts that are classified as trading. Fair values are based on quoted market prices. Securities lending collateral: Fair values of securities lending collateral are based on quoted market prices, where available. These fair values are obtained primarily from third party pricing services, which generally use Level I or Level II inputs for the determination of fair value, to facilitate fair value measurements and disclosures. Derivatives: Fair values are based on the quoted market prices by the financial institution that is the counterparty to the derivative transaction. We independently verify prices provided by the counterparties using valuation models that incorporate market observable inputs for similar derivative transactions. Long-term receivable: Fair value is estimated based on discounted cash flow analysis using assumptions for inputs such as expected cash flow and discount rates that are not observable in the markets. A summary of fair value measurements by level for assets and liabilities measured at fair value on a recurring basis at June 30, 2015 and December 31, 2014 is as follows: Level I Level II Level III Total June 30, 2015 Assets: Cash equivalents $ 686.4 $ — $ — $ 686.4 Investments available-for-sale: Fixed maturity securities: United States Government securities 325.9 — — 325.9 Government sponsored securities — 88.2 — 88.2 States, municipalities and political subdivisions, tax-exempt — 5,964.8 — 5,964.8 Corporate securities 212.1 8,960.7 192.4 9,365.2 Options embedded in convertible debt securities — 0.8 — 0.8 Residential mortgage-backed securities — 1,933.0 — 1,933.0 Commercial mortgage-backed securities — 432.2 2.8 435.0 Other debt securities 81.5 649.5 6.3 737.3 Total fixed maturity securities 619.5 18,029.2 201.5 18,850.2 Equity securities 1,558.2 124.8 54.1 1,737.1 Other invested assets, current 23.4 — — 23.4 Securities lending collateral 943.1 775.2 — 1,718.3 Derivatives excluding embedded options (reported with other assets) — 218.0 — 218.0 Total assets $ 3,830.6 $ 19,147.2 $ 255.6 $ 23,233.4 Liabilities: Derivatives excluding embedded options (reported with other liabilities) $ — $ (215.1 ) $ — $ (215.1 ) Total liabilities $ — $ (215.1 ) $ — $ (215.1 ) December 31, 2014 Assets: Cash equivalents $ 573.2 $ — $ — $ 573.2 Investments available-for-sale: Fixed maturity securities: United States Government securities 320.0 — — 320.0 Government sponsored securities — 95.0 — 95.0 States, municipalities and political subdivisions, tax-exempt — 5,733.6 — 5,733.6 Corporate securities 7.1 8,180.8 144.6 8,332.5 Options embedded in convertible debt securities — 98.7 — 98.7 Residential mortgage-backed securities — 2,159.0 — 2,159.0 Commercial mortgage-backed securities — 506.6 3.3 509.9 Other debt securities 89.2 627.3 6.6 723.1 Total fixed maturity securities 416.3 17,401.0 154.5 17,971.8 Equity securities 1,696.9 192.9 48.3 1,938.1 Other invested assets, current 20.2 — — 20.2 Securities lending collateral 808.3 706.9 — 1,515.2 Derivatives excluding embedded options (reported with other assets) — 224.8 — 224.8 Total assets $ 3,514.9 $ 18,525.6 $ 202.8 $ 22,243.3 Liabilities: Derivatives excluding embedded options (reported with other liabilities) $ — $ (260.4 ) $ — $ (260.4 ) Total liabilities $ — $ (260.4 ) $ — $ (260.4 ) A reconciliation of the beginning and ending balances of assets measured at fair value on a recurring basis using Level III inputs for the three months ended June 30, 2015 and 2014 is as follows: Corporate Securities Commercial Mortgage- backed Securities Other Debt Securities Equity Securities Long-term Receivable Total Three months ended June 30, 2015 Beginning balance at April 1, 2015 $ 165.5 $ 3.2 $ 2.6 $ 51.8 $ — $ 223.1 Total gains (losses): Recognized in net income (0.8 ) — — (0.4 ) — (1.2 ) Recognized in accumulated other comprehensive income 1.4 — — (0.4 ) — 1.0 Purchases 57.2 — 3.7 4.3 — 65.2 Sales (4.1 ) — — (1.2 ) — (5.3 ) Settlements (11.3 ) (0.4 ) — — — (11.7 ) Transfers into Level III 4.2 — — — — 4.2 Transfers out of Level III (19.7 ) — — — — (19.7 ) Ending balance at June 30, 2015 $ 192.4 $ 2.8 $ 6.3 $ 54.1 $ — $ 255.6 Change in unrealized losses included in net income related to assets still held for the three months ended June 30, 2015 $ — $ — $ — $ (0.2 ) $ — $ (0.2 ) Three months ended June 30, 2014 Beginning balance at April 1, 2014 $ 114.0 $ 3.1 $ 14.8 $ 43.2 $ 21.6 $ 196.7 Total gains (losses): Recognized in net income (3.0 ) — — (0.4 ) 10.6 7.2 Recognized in accumulated other comprehensive income 9.6 — 0.1 7.1 — 16.8 Purchases 11.6 3.6 3.0 1.7 — 19.9 Sales (4.5 ) — — (8.5 ) — (13.0 ) Settlements (1.5 ) — (0.1 ) — — (1.6 ) Transfers into Level III 24.2 — — — — 24.2 Transfers out of Level III — (3.1 ) — — — (3.1 ) Ending balance at June 30, 2014 $ 150.4 $ 3.6 $ 17.8 $ 43.1 $ 32.2 $ 247.1 Change in unrealized losses included in net income related to assets still held for the three months ended June 30, 2014 $ (3.6 ) $ — $ — $ (0.4 ) $ — $ (4.0 ) A reconciliation of the beginning and ending balances of assets measured at fair value on a recurring basis using Level III inputs for the six months ended June 30, 2015 and 2014 is as follows: Corporate Securities Commercial Mortgage- backed Securities Other Debt Securities Equity Securities Long-term Receivable Total Six Months Ended June 30, 2015 Beginning balance at January 1, 2015 $ 144.6 $ 3.3 $ 6.6 $ 48.3 $ — $ 202.8 Total gains (losses): Recognized in net income (1.0 ) — 0.2 (1.2 ) — (2.0 ) Recognized in accumulated other comprehensive income 3.0 — (0.2 ) 0.9 — 3.7 Purchases 89.6 — 3.7 11.8 — 105.1 Sales (4.1 ) — (0.9 ) (5.7 ) — (10.7 ) Settlements (24.9 ) (0.5 ) (0.1 ) — — (25.5 ) Transfers into Level III 4.9 — — — — 4.9 Transfers out of Level III (19.7 ) — (3.0 ) — — (22.7 ) Ending balance at June 30, 2015 $ 192.4 $ 2.8 $ 6.3 $ 54.1 $ — $ 255.6 Change in unrealized losses included in net income related to assets still held for the six months ended June 30, 2015 $ (0.6 ) $ — $ — $ (1.0 ) $ — $ (1.6 ) Six Months Ended June 30, 2014 Beginning balance at January 1, 2014 $ 115.2 $ 6.5 $ 14.8 $ 41.4 $ — $ 177.9 Total gains (losses): Recognized in net income (6.3 ) — — (0.7 ) 32.2 25.2 Recognized in accumulated other comprehensive income 12.7 — 0.3 1.3 — 14.3 Purchases 20.9 3.6 3.0 10.7 — 38.2 Sales (6.2 ) — — (9.6 ) — (15.8 ) Settlements (3.6 ) (3.4 ) (0.3 ) — — (7.3 ) Transfers into Level III 24.2 — — — — 24.2 Transfers out of Level III (6.5 ) (3.1 ) — — — (9.6 ) Ending balance at June 30, 2014 $ 150.4 $ 3.6 $ 17.8 $ 43.1 $ 32.2 $ 247.1 Change in unrealized losses included in net income related to assets still held for the six months ended June 30, 2014 $ (7.6 ) $ — $ — $ (0.7 ) $ — $ (8.3 ) Transfers between levels, if any, are recorded as of the beginning of the reporting period. There were no material transfers between levels during the three and six months ended June 30, 2015 or 2014 . Certain assets and liabilities are measured at fair value on a nonrecurring basis; that is, the instruments are not measured at fair value on an ongoing basis but are subject to fair value adjustments only in certain circumstances. As disclosed in Note 4, “Business Acquisition and Divestiture”, we completed our acquisition of Simply Healthcare on February 17, 2015. The values of net assets acquired in our acquisition of Simply Healthcare and resulting goodwill and other intangible assets were recorded at fair value primarily using Level III inputs. The majority of Simply Healthcare's assets acquired and liabilities assumed were recorded at their carrying values as of the respective date of acquisition, as their carrying values approximated their fair values due to their short-term nature. The fair values of goodwill and other intangible assets acquired in our acquisition of Simply Healthcare were internally estimated based on the income approach. The income approach estimates fair value based on the present value of the cash flows that the assets could be expected to generate in the future. We developed internal estimates for the expected cash flows and discount rate in the present value calculation. Other than the assets acquired and liabilities assumed in our acquisition of Simply Healthcare described above, there were no other assets or liabilities measured at fair value on a nonrecurring basis during the three and six months ended June 30, 2015 or 2014 . Our valuation policy is determined by members of our treasury and accounting departments. Whenever possible, our policy is to obtain quoted market prices in active markets to estimate fair values for recognition and disclosure purposes. Where quoted market prices in active markets are not available, fair values are estimated using discounted cash flow analyses, broker quotes or other valuation techniques. These techniques are significantly affected by our assumptions, including discount rates and estimates of future cash flows. Potential taxes and other transaction costs are not considered in estimating fair values. Our valuation policy is generally to obtain only one quoted price for each security from third party pricing services, which are derived through recently reported trades for identical or similar securities making adjustments through the reporting date based upon available market observable information. When broker quotes are used, we generally obtain only one broker quote per security. As we are responsible for the determination of fair value, we perform monthly analysis on the prices received from the pricing services to determine whether the prices are reasonable estimates of fair value. This analysis is performed by our internal treasury personnel who are familiar with our investment portfolios, the pricing services engaged and the valuation techniques and inputs used. Our analysis includes a review of month-to-month price fluctuations. If unusual fluctuations are noted in this review, we may obtain additional information from other pricing services to validate the quoted price. There were no adjustments to quoted market prices obtained from the pricing services during the three and six months ended June 30, 2015 or 2014 . In addition to the preceding disclosures on assets recorded at fair value in the consolidated balance sheets, FASB guidance also requires the disclosure of fair values for certain other financial instruments for which it is practicable to estimate fair value, whether or not such values are recognized in the consolidated balance sheets. Non-financial instruments such as real estate, property and equipment, other current assets, deferred income taxes, intangible assets and certain financial instruments, such as policy liabilities, are excluded from the fair value disclosures. Therefore, the fair value amounts cannot be aggregated to determine our underlying economic value. The carrying amounts reported in the consolidated balance sheets for cash, accrued investment income, premium and self-funded receivables, other receivables, unearned income, accounts payable and accrued expenses, income taxes receivable/payable, security trades pending payable, securities lending payable and certain other current liabilities approximate fair value because of the short term nature of these items. These assets and liabilities are not listed in the table below. The following methods, assumptions and inputs were used to estimate the fair value of each class of financial instrument that is recorded at its carrying value on the consolidated balance sheets: Other invested assets, long-term : Other invested assets, long-term include primarily our investments in limited partnerships, joint ventures and other non-controlled corporations, as well as the cash surrender value of corporate-owned life insurance policies. Investments in limited partnerships, joint ventures and other non-controlled corporations are carried at our share in the entities’ undistributed earnings, which approximates fair value. The carrying value of corporate-owned life insurance policies represents the cash surrender value as reported by the respective insurer, which approximates fair value. Short-term borrowings : The fair value of our short-term borrowings is based on quoted market prices for the same or similar debt, or, if no quoted market prices were available, on the current market interest rates estimated to be available to us for debt of similar terms and remaining maturities. Long-term debt – commercial paper: The carrying amount for commercial paper approximates fair value as the underlying instruments have variable interest rates at market value. Long-term debt – senior unsecured notes, remarketable subordinated notes and surplus notes : The fair values of our notes are based on quoted market prices in active markets for the same or similar debt, or, if no quoted market prices are available, on the current market observable rates estimated to be available to us for debt of similar terms and remaining maturities. Long-term debt – convertible debentures : The fair value of our convertible debentures is based on the market price in the active private market in which the convertible debentures trade. A summary of the estimated fair values by level of each class of financial instrument that is recorded at its carrying value on our consolidated balance sheets at June 30, 2015 and December 31, 2014 are as follows: Carrying Value Estimated Fair Value Level I Level II Level III Total June 30, 2015 Assets: Other invested assets, long-term $ 1,803.3 $ — $ — $ 1,803.3 $ 1,803.3 Liabilities: Debt: Short-term borrowings 540.0 — 540.0 — 540.0 Commercial paper 697.4 — 697.4 — 697.4 Notes 14,926.3 — 15,148.6 — 15,148.6 Convertible debentures 469.6 — 1,608.4 — 1,608.4 December 31, 2014 Assets: Other invested assets, long-term $ 1,695.9 $ — $ — $ 1,695.9 $ 1,695.9 Liabilities: Debt: Short-term borrowings 400.0 — 400.0 — 400.0 Notes 13,687.5 — 14,794.8 — 14,794.8 Convertible debentures 956.4 — 2,581.9 — 2,581.9

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes During the three months ended June 30, 2015 and 2014 , we recognized income tax expense of $698.9 and $532.6 , respectively, which represents effective tax rates of 44.9% and 42.1% , respectively. The increase in income tax expense was primarily due to increased income before income taxes and the increase to the non-tax deductible Health Insurance Provider Fee, or HIP Fee. For the three months ended June 30, 2015 and 2014, the HIP Fee resulted in additional income tax expense of $114.2 and $80.5 , respectively. The increase in the effective income tax rate was primarily due to the increase in the non-tax deductible HIP Fee. During the six months ended June 30, 2015 and 2014 , we recognized income tax expense of $1,402.8 and $971.3 , respectively, which represents effective tax rates of 44.9% and 40.6% , respectively. The increase in income tax expense was primarily due to increased income before income taxes and the increase to the non-tax deductible HIP Fee. For the six months ended June 30, 2015 and 2014, the HIP Fee resulted in additional income tax expense of $227.5 and $161.0 , respectively. The increase was further impacted due to favorable 2014 discrete tax adjustments related to state income tax audits, including refund claims filed, and adjustments to state deferred tax liabilities in 2014 resulting from a decrease in the Indiana statutory income tax rate. The increase in the effective tax rate was primarily due to the increase to the non-tax deductible HIP Fee, the favorable 2014 discrete tax adjustments, and adjustments to the state deferred tax liabilities in 2014, discussed above.

Retirement Benefits

Retirement Benefits	6 Months Ended
	Jun. 30, 2015
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Retirement Benefits	Retirement Benefits The components of net periodic (credit) benefit cost included in the consolidated statements of income for the three months ended June 30, 2015 and 2014 are as follows: Pension Benefits Other Benefits 2015 2014 2015 2014 Service cost $ 3.3 $ 3.2 $ 0.6 $ 0.8 Interest cost 17.1 18.5 5.8 6.5 Expected return on assets (35.9 ) (34.3 ) (5.9 ) (5.9 ) Recognized actuarial loss 6.5 5.2 3.8 2.4 Settlement loss 1.7 1.4 — — Amortization of prior service credit (0.2 ) (0.2 ) (3.6 ) (3.6 ) Net periodic (credit) benefit cost $ (7.5 ) $ (6.2 ) $ 0.7 $ 0.2 The components of net periodic (credit) benefit cost included in the consolidated statements of income for the six months ended June 30, 2015 and 2014 are as follows: Pension Benefits Other Benefits 2015 2014 2015 2014 Service cost $ 6.6 $ 6.5 $ 1.1 $ 1.6 Interest cost 34.1 37.0 11.7 13.1 Expected return on assets (71.6 ) (68.7 ) (11.8 ) (11.7 ) Recognized actuarial loss 12.9 10.5 7.6 4.7 Settlement loss 3.0 2.5 — — Amortization of prior service credit (0.4 ) (0.4 ) (7.2 ) (7.2 ) Net periodic (credit) benefit cost $ (15.4 ) $ (12.6 ) $ 1.4 $ 0.5 For the year ending December 31, 2015 , no material contributions are expected to be necessary to meet the Employee Retirement Income Security Act, or ERISA, required funding levels; however, we may elect to make discretionary contributions up to the maximum amount deductible for income tax purposes. No contributions were made to our retirement benefit plans during the six months ended June 30, 2015 or 2014 .

Debt

Debt	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Debt	Debt The carrying value of long-term debt at June 30, 2015 and December 31, 2014 consists of the following: June 30, 2015 December 31, 2014 Senior unsecured notes: 1.250%, due 2015 $ 624.9 $ 624.3 2.375%, due 2017 400.0 398.9 5.875%, due 2017 527.2 526.7 1.875%, due 2018 621.6 616.4 2.300%, due 2018 645.1 644.3 2.250%, due 2019 843.0 842.1 7.000%, due 2019 438.7 438.5 4.350%, due 2020 698.8 695.3 3.700%, due 2021 695.9 695.6 3.125%, due 2022 842.2 841.6 3.300%, due 2023 991.8 991.2 3.500%, due 2024 790.4 789.8 5.950%, due 2034 444.4 444.4 5.850%, due 2036 767.8 767.7 6.375%, due 2037 639.5 639.3 5.800%, due 2040 193.7 206.4 4.625%, due 2042 885.6 885.4 4.650%, due 2043 985.2 985.0 4.650%, due 2044 790.3 790.1 5.100%, due 2044 593.2 593.1 4.850%, due 2054 246.6 246.5 Remarketable subordinated notes: 1.900%, due 2028 1,235.5 — Surplus notes: 9.000%, due 2027 24.9 24.9 Senior convertible debentures: 2.750%, due 2042 469.6 956.4 Variable rate debt: Commercial paper program 697.4 — Total long-term debt 16,093.3 14,643.9 Current portion of long-term debt (624.9 ) (624.3 ) Long-term debt, less current portion $ 15,468.4 $ 14,019.6 We generally issue senior unsecured notes for long-term borrowing purposes. At June 30, 2015 , we had $13,665.9 outstanding under these notes. During the three months ended March 31, 2015, we repurchased $13.0 of outstanding principal balance of certain senior unsecured notes, plus applicable premium for early redemption plus accrued and unpaid interest, for cash totaling $16.2 . We recognized a loss on extinguishment of debt of $3.4 . We did not repurchase any senior unsecured noted during the three months ended June 30, 2015 . On May 12, 2015 , we issued 25.0 Equity Units, pursuant to an underwriting agreement dated May 6, 2015, in an aggregate principal amount of $1,250.0 . Each Equity Unit has a stated amount of $50 (whole dollars) and consists of a purchase contract obligating the holder to purchase a certain number of shares of our common stock on May 1, 2018 , subject to earlier termination or settlement, for a price in cash of $50 (whole dollars); and a 5% undivided beneficial ownership interest in $1,000 (whole dollars) principal amount of our 1.900% remarketable subordinated notes, or RSNs, due 2028. We received $1,228.8 in cash proceeds from issuance of the Equity Units, net of underwriting discounts and commissions and offering expenses payable by us, and recorded $1,250.0 in long-term debt. The proceeds will be used for general corporate purposes, including, but not limited to, the repurchase of a portion of our outstanding senior convertible debentures due 2042. On May 1, 2018, if the applicable market value of our common stock is equal to or greater than $207.805 per share, the settlement rate will be 0.2406 shares of our common stock. If the applicable market value of our common stock is less than $207.805 per share but greater than $143.865 per share, the settlement rate will be a number of shares of our common stock equal to $50 (whole dollars) divided by the applicable market value of our common stock. If the applicable market value of common stock is less than or equal to $143.865, the settlement rate will be 0.3475 shares of our common stock. Holders of the Equity Units may elect early settlement at a minimum settlement rate of 0.2406 shares of our common stock for each purchase contract being settled. The RSNs are pledged as collateral to secure the purchase of common stock under the related stock purchase contracts. Quarterly interest payments on the RSNs will commence on August 1, 2015, subject to any termination event or optional re-marketing. The RSNs are scheduled to be remarketed during the five business day period ending on April 26, 2018 and may be remarketed earlier, at our election, during the period from January 30, 2018 through April 12, 2018. Following the re-marketing, the interest rate on the RSNs will be set to current market rates and interest will be payable semi-annually. At June 30, 2015, the present value of the stock purchase contract liability was $120.9 and is included in other current liabilities and other noncurrent liabilities with a corresponding offset to additional paid-in capital in our consolidated balance sheet. Contract adjustment payments will commence on August 1, 2015 at a rate of 3.350% per annum on the stated amount per Equity Unit. Subject to certain specified terms and conditions, we have the right to defer payments on all or part the contract adjustment payments but not beyond the contract settlement date and we have the right to defer payment of interest on the RSNs but not beyond the purchase contract settlement date or maturity date. We have an unsecured surplus note with an outstanding principal balance of $24.9 at June 30, 2015 . We have a senior revolving credit facility, or the Facility, with certain lenders for general corporate purposes. The Facility, as amended, provides credit up to $2,000.0 , and matures on September 29, 2016 . There were no amounts outstanding under this Facility as of June 30, 2015 or at any time during the three and six months then ended. We have an authorized commercial paper program of up to $2,500.0 , the proceeds of which may be used for general corporate purposes. At June 30, 2015 , we had $697.4 outstanding under this program. We have outstanding senior convertible debentures due 2042, or the Debentures, which are governed by an indenture between us and The Bank of New York Mellon Trust Company, N.A., as trustee. We have accounted for the Debentures in accordance with the cash conversion guidance in FASB guidance for debt with conversion and other options. As a result, the value of the embedded conversion option has been bifurcated from its debt host and recorded as a component of additional paid-in capital (net of deferred taxes and equity issuance costs) in our consolidated balance sheets. During the three months ended June 30, 2015, we repurchased $700.5 aggregate principal balance of the Debentures. In addition, $66.5 aggregate principal balance was surrendered for conversion by certain holders in accordance with the terms and provisions of the indenture governing the Debentures. We elected to settle the excess of the principal amount of the repurchases and the conversions with cash for total payments of $1,646.3 . We recognized a gain on extinguishment of debt of $2.9 based on the fair values of the debt on the repurchase and conversion settlement dates. The following table summarizes at June 30, 2015 the related balances, conversion rate and conversion price of the Debentures: Outstanding principal amount $ 733.0 Unamortized debt discount $ 254.7 Net debt carrying amount $ 469.6 Equity component carrying amount $ 265.7 Conversion rate (shares of common stock per $1,000 of principal amount) 13.4231 Effective conversion price (per $1,000 of principal amount) $ 74.4977 We have $540.0 in outstanding short-term borrowings from various Federal Home Loan Banks at June 30, 2015 with fixed interest rates of 0.194% .

Commitments And Contingencies

Commitments And Contingencies	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingencies	Commitments and Contingencies Litigation In the ordinary course of business, we are defendants in, or parties to, a number of pending or threatened legal actions or proceedings. To the extent a plaintiff or plaintiffs in the following cases have specified in their complaint or in other court filings the amount of damages being sought, we have noted those alleged damages in the descriptions below. With respect to the cases described below, we contest liability and/or the amount of damages in each matter and believe we have meritorious defenses. We are defending a certified class action filed as a result of the 2001 demutualization of Anthem Insurance Companies, Inc., or Anthem Insurance. The lawsuit names Anthem Insurance as well as Anthem, Inc. and is captioned Ronald Gold, et al. v. Anthem, Inc. et al. Anthem Insurance’s 2001 Plan of Conversion, or the Plan, provided for the conversion of Anthem Insurance from a mutual insurance company into a stock insurance company pursuant to Indiana law. Under the Plan, Anthem Insurance distributed the fair value of the company at the time of conversion to its Eligible Statutory Members, or ESMs, in the form of cash or Anthem common stock in exchange for their membership interests in the mutual company. Plaintiffs in Gold allege that Anthem Insurance distributed value to the wrong ESMs. Cross motions for summary judgment were granted in part and denied in part on July 26, 2006 with regard to the issue of sovereign immunity asserted by co-defendant, the state of Connecticut, or the State. The trial court also denied our motion for summary judgment as to plaintiffs’ claims on January 10, 2005. The State appealed the denial of its motion to the Connecticut Supreme Court. We filed a cross-appeal on the sovereign immunity issue. On May 11, 2010, the Supreme Court reversed the judgment of the trial court denying the State’s motion to dismiss the plaintiff’s claims under sovereign immunity and dismissed our cross-appeal. The case was remanded to the trial court for further proceedings. Plaintiffs’ motion for class certification was granted on December 15, 2011. We and the plaintiffs filed renewed cross-motions for summary judgment on January 24, 2013. On August 19, 2013, the trial court denied plaintiffs' motion for summary judgment. The trial court deferred a final ruling on our motion for summary judgment. On March 6, 2014, the trial court denied our motion for summary judgment finding that an issue of material fact existed. A trial on liability commenced on October 14, 2014 and concluded on October 16, 2014. On June 12, 2015, the court entered judgment for Anthem Insurance on all issues, finding that (1) Anthem Insurance correctly determined the State to be an ESM, not Plaintiffs; (2) Anthem Insurance acted in good faith in making this determination, while Plaintiffs failed to present sufficient evidence to override a presumption that Anthem Insurance’s ESM determination was correct; and (3) Plaintiffs failed to prove the breach of any contractual obligation. On July 1, 2015, Plaintiffs filed a notice of appeal from the judgment entered for Anthem Insurance. We are currently a defendant in eleven putative class actions relating to out-of-network, or OON, reimbursement that were consolidated into a single multi-district lawsuit called In re WellPoint, Inc. (n/k/a Anthem, Inc.) Out-of-Network “UCR” Rates Litigation that is pending in the United States District Court for the Central District of California. The lawsuits were filed in 2009. The plaintiffs include current and former members on behalf of a putative class of members who received OON services for which the defendants paid less than billed charges, the American Medical Association, four state medical associations, OON physicians, OON non-physician providers, the American Podiatric Medical Association, California Chiropractic Association and the California Psychological Association on behalf of putative classes of OON physicians and all OON non-physician health care providers. The plaintiffs have filed several amended complaints alleging that the defendants violated the Racketeer Influenced and Corrupt Organizations Act, or RICO, the Sherman Antitrust Act, ERISA, federal regulations, and state law by using an OON reimbursement database called Ingenix and by using non-Ingenix OON reimbursement methodologies. We have filed motions to dismiss in response to each of those amended complaints. Our motions to dismiss have been granted in part and denied in part by the court. The most recent pleading filed by the plaintiffs is a Fourth Amended Complaint to which we filed a motion to dismiss most, but not all, of the claims. In July 2013 the court issued an order granting in part and denying in part our motion. The court held that the state and federal anti-trust claims along with the RICO claims should be dismissed in their entirety with prejudice. The court further found that the ERISA claims, to the extent they involved non-Ingenix methodologies, along with those that involved our alleged non-disclosures should be dismissed with prejudice. The court also dismissed most of the plaintiffs’ state law claims with prejudice. The only claims that remain after the court’s decision are an ERISA benefits claim relating to claims priced based on Ingenix, a breach of contract claim on behalf of one subscriber plaintiff, a breach of implied covenant claim on behalf of one subscriber plaintiff, and one subscriber plaintiff’s claim under the California Unfair Competition Law. The plaintiffs filed a motion for reconsideration of the motion to dismiss order, which the court granted in part and denied in part. The court ruled that the plaintiffs adequately allege that one Georgia provider plaintiff is deemed to have exhausted administrative remedies regarding non-Ingenix methodologies based on the facts alleged regarding that plaintiff so those claims are back in the case. Fact discovery is complete. The plaintiffs filed a motion for class certification in November 2013 seeking the following classes: (1) a subscriber ERISA class as to OON claims processed using the Ingenix database as the pricing methodology; (2) a physician provider class as to OON claims processed using Ingenix; (3) a non-physician provider class as to OON claims processed using Ingenix; (4) a provider ERISA class as to OON claims processed using non-Ingenix pricing methodologies; (5) a California subscriber breach of contract/unfair competition class; and (6) a subscriber breach of implied covenant class for all Anthem states except California. Following expert discovery and briefing, oral argument was held on the motion. In late 2014, the court denied the plaintiffs' motion for class certification in its entirety. The California subscriber plaintiffs filed a motion for leave to file a renewed motion for class certification with more narrowly defined proposed classes, which the court denied. The parties have a January 2016 deadline for filing motions for summary judgment. Earlier in the case, in 2009, we filed a motion in the United States District Court for the Southern District of Florida, or the Florida Court, to enjoin the claims brought by the physician plaintiffs and certain medical association plaintiffs based on prior litigation releases, which was granted in 2011. The Florida Court ordered those plaintiffs to dismiss their claims that are barred by the release. The plaintiffs then filed a petition for declaratory judgment asking the court to find that these claims are not barred by the releases from the prior litigation. We filed a motion to dismiss the declaratory judgment action, which was granted. The plaintiffs appealed the dismissal of the declaratory judgment to the United States Court of Appeals for the Eleventh Circuit, but the dismissal was upheld. The enjoined physicians and some of the medical associations did not dismiss their barred claims. The Florida Court found those enjoined plaintiffs in contempt and sanctioned them in July 2012. Those plaintiffs appealed the Florida Court’s sanctions order to the United States Court of Appeals for the Eleventh Circuit. The Eleventh Circuit upheld the Florida court’s enforcement of the injunction as it relates to the plaintiffs’ RICO and antitrust claims, but vacated it as it relates to certain ERISA claims. The plaintiffs filed a petition for rehearing en banc as to the antitrust claims only, which was denied. The plaintiffs then filed a petition for writ of certiorari with the U.S. Supreme Court. The American Medical Association filed an amicus brief in support of the petition. The U.S. Supreme Court denied the petition on February 23, 2015. We intend to vigorously defend these suits; however, their ultimate outcome cannot be presently determined. We are a defendant in multiple lawsuits that were initially filed in 2012 against the BCBSA as well as Blue Cross and/or Blue Shield licensees across the country. The cases were consolidated into a single multi-district lawsuit called In re Blue Cross Blue Shield Antitrust Litigation that is pending in the United States District Court for the Northern District of Alabama. Generally, the suits allege that the BCBSA and the Blue plans have engaged in a conspiracy to horizontally allocate geographic markets through license agreements, best efforts rules (which limit the percentage of non-Blue revenue of each plan), restrictions on acquisitions and other arrangements in violation of the Sherman Antitrust Act and related state laws. The cases were brought by two putative nationwide classes of plaintiffs, health plan subscribers and providers. Subscriber and provider plaintiffs each filed consolidated amended complaints on July 1, 2013. The consolidated amended subscriber complaint was also brought on behalf of putative state classes of health plan subscribers in Alabama, Arkansas, California, Florida, Hawaii, Illinois, Louisiana, Michigan, Mississippi, Missouri, New Hampshire, North Carolina, Pennsylvania, Rhode Island, South Carolina, Tennessee, and Texas. Defendants filed motions to dismiss in September 2013, which were argued in April 2014. In June 2014, the court denied the majority of the motions, ruling that plaintiffs had alleged sufficient facts at this stage of the litigation to avoid dismissal of their claims. Following the subsequent filing of amended complaints by each of the subscriber and provider plaintiffs, we filed our answer and asserted our affirmative defenses in December 2014. Discovery has commenced. We intend to vigorously defend these suits; however, their ultimate outcome cannot be presently determined. Where available information indicates that it is probable that a loss has been incurred as of the date of the consolidated financial statements and we can reasonably estimate the amount of that loss, we accrue the estimated loss by a charge to income. In many proceedings, however, it is difficult to determine whether any loss is probable or reasonably possible. In addition, even where loss is possible or an exposure to loss exists in excess of the liability already accrued with respect to a previously identified loss contingency, it is not always possible to reasonably estimate the amount of the possible loss or range of loss. With respect to many of the proceedings to which we are a party, we cannot provide an estimate of the possible losses, or the range of possible losses in excess of the amount, if any, accrued, for various reasons, including but not limited to some or all of the following: (i) there are novel or unsettled legal issues presented, (ii) the proceedings are in early stages, (iii) there is uncertainty as to the likelihood of a class being certified or decertified or the ultimate size and scope of the class, (iv) there is uncertainty as to the outcome of pending appeals or motions, (v) there are significant factual issues to be resolved, and/or (vi) in many cases, the plaintiffs have not specified damages in their complaint or in court filings. For those legal proceedings where a loss is probable, or reasonably possible, and for which it is possible to reasonably estimate the amount of the possible loss or range of losses, we currently believe that the range of possible losses, in excess of established reserves, for all of those proceedings is from $0.0 to approximately $250.0 at June 30, 2015 . This estimated aggregate range of reasonably possible losses is based upon currently available information taking into account our best estimate of such losses for which such an estimate can be made. Cyber Attack Incident In February 2015, we reported that we were the target of a sophisticated external cyber attack. The attackers gained unauthorized access to certain of our information technology systems and obtained personal information related to many individuals and employees, such as names, birthdays, health care identification/social security numbers, street addresses, email addresses, phone numbers and employment information, including income data. To date, there is no evidence that credit card or medical information, such as claims, test results or diagnostic codes, were targeted, accessed or obtained, although no assurance can be given that we will not identify additional information that was accessed or obtained. Currently, we are in the process of addressing the cyber attack and supporting federal law enforcement efforts to identify the responsible parties. Upon discovery of the cyber attack, we took immediate action to remediate the security vulnerability and retained a cybersecurity firm to evaluate our systems and identify solutions based on the evolving landscape. We will provide credit monitoring and identity protection services to those who have been affected by this cyber attack. While the cyber attack did not have an impact on our business, cash flows, financial condition and results of operations for the year ended December 31, 2014, we have incurred expenses subsequent to the cyber attack to investigate and remediate this matter and expect to continue to incur expenses of this nature in the foreseeable future. Although we are unable to quantify the ultimate magnitude of such expenses and any other impact to our business from this incident at this time, they may be significant. We will recognize these expenses in the periods in which they are incurred. Actions have been filed in various federal and state courts and other claims have been or may be asserted against us on behalf of current or former members, current or former employees, other individuals, shareholders or others seeking damages or other related relief, allegedly arising out of the cyber attack. State and federal agencies, including state insurance regulators, state attorneys general, the Health and Human Services Office of Civil Rights and the Federal Bureau of Investigations, are investigating events related to the cyber attack, including how it occurred, its consequences and our responses. Although we are cooperating in these investigations, we may be subject to fines or other obligations, which may have an adverse effect on how we operate our business and our results of operations. With respect to the civil actions, a motion to transfer was filed with the Judicial Panel on Multidistrict Litigation on February 10, 2015 and was subsequently heard by the Panel on May 28, 2015. On June 8, 2015, the Panel entered its order transferring the consolidated matter to the U.S. District Court for the Northern District of California. We have contingency plans and insurance coverage for certain expenses and potential liabilities of this nature, however, the coverage may not be sufficient to cover all claims and liabilities. While a loss from these matters is reasonably possible, we cannot reasonably estimate a range of possible losses because our investigation into the matter is ongoing, the proceedings remain in the early stages, alleged damages have not been specified, there is uncertainty as to the likelihood of a class or classes being certified or the ultimate size of any class if certified, and there are significant factual and legal issues to be resolved. Other Contingencies From time to time, we and certain of our subsidiaries are parties to various legal proceedings, many of which involve claims for coverage encountered in the ordinary course of business. We, like HMOs and health insurers generally, exclude certain health care and other services from coverage under our HMO, PPO and other plans. We are, in the ordinary course of business, subject to the claims of our enrollees arising out of decisions to restrict or deny reimbursement for uncovered services. The loss of even one such claim, if it results in a significant punitive damage award, could have a material adverse effect on us. In addition, the risk of potential liability under punitive damage theories may increase significantly the difficulty of obtaining reasonable settlements of coverage claims. In addition to the lawsuits described above, we are also involved in other pending and threatened litigation of the character incidental to our business, and are from time to time involved as a party in various governmental investigations, audits, reviews and administrative proceedings. These investigations, audits, reviews and administrative proceedings include routine and special inquiries by state insurance departments, state attorneys general, the U.S. Attorney General and subcommittees of the U.S. Congress. Such investigations, audits, reviews and administrative proceedings could result in the imposition of civil or criminal fines, penalties, other sanctions and additional rules, regulations or other restrictions on our business operations. Any liability that may result from any one of these actions, or in the aggregate, could have a material adverse effect on our consolidated financial position or results of operations. The National Organization of Life & Health Insurance Guaranty Associations, or NOLHGA, is a voluntary organization consisting of the state life and health insurance guaranty associations located throughout the U.S. Such associations, working together with NOLHGA, provide a safety net for their state’s policyholders, ensuring that they continue to receive coverage, subject to state maximum limits, even if their insurer is declared insolvent. We are aware that the Pennsylvania Insurance Commissioner, or Insurance Commissioner, has placed Penn Treaty Network America Insurance Company and its subsidiary American Network Insurance Company, or collectively Penn Treaty, in rehabilitation, an intermediate action before insolvency. The state court denied the Insurance Commissioner’s petition for the liquidation of Penn Treaty and ordered the Insurance Commissioner to file an updated plan of rehabilitation. The Insurance Commissioner filed an initial plan of rehabilitation on April 30, 2013, an amended plan on August 8, 2014 and a second amended plan on October 8, 2014. The state court commenced a hearing in connection with the second amended plan on July 13, 2015, which hearing has been adjourned pending further discovery. Also, on July 20, 2015, the Pennsylvania Supreme Court affirmed the state court's decision to deny the petition for liquidation. In the event rehabilitation of Penn Treaty is unsuccessful and Penn Treaty is declared insolvent and placed in liquidation, we and other insurers may be required to pay a portion of their policyholder claims through state guaranty association assessments in future periods. Given the uncertainty around whether Penn Treaty will ultimately be declared insolvent and, if so, the amount of the insolvency, the amount and timing of any associated future guaranty fund assessments, and the availability and amount of any potential premium tax and other offsets, we currently cannot estimate our net exposure, if any, to this potential insolvency. We will continue to monitor the situation and may record a liability and expense in future reporting periods, which could be material to our cash flows and results of operations. Contractual Obligations and Commitments We are a party to an agreement with Express Scripts, Inc., or Express Scripts, whereby Express Scripts is the exclusive provider of pharmacy benefit management, or PBM, services to our plans, excluding one Amerigroup subsidiary and certain self-insured members, which have exclusive agreements with different PBM service providers. It is expected that the Amerigroup subsidiary will complete its transition to the Express Scripts agreement during 2015. The initial term of this agreement expires on December 31, 2019. Under this agreement, Express Scripts is the exclusive provider of certain specified PBM services, such as pharmacy network management, home delivery, pharmacy customer service, claims processing, rebate management, drug utilization and specialty pharmaceutical management services. Accordingly, the agreement contains certain financial and operational requirements obligating both Express Scripts and us. Express Scripts’ primary obligations relate to the performance of such services and meeting certain pricing guarantees and performance standards. Our primary obligations relate to oversight, provision of data, payment for services and certain minimum volume requirements. The failure by either party to meet the respective requirements could potentially serve as a basis for financial penalties or early termination of the contract. We believe we have appropriately recognized all rights and obligations under this contract at June 30, 2015 . During December 2014, we entered into a new agreement with International Business Machines Corporation to provide information technology infrastructure services. This new agreement supersedes certain prior agreements and also includes provisions for additional services. Our remaining commitment under this agreement at June 30, 2015 was $430.0 through March 31, 2020 . We have the ability to terminate this agreement upon the occurrence of certain events, subject to early termination fees. On March 31, 2009 , we entered into an agreement with Affiliated Computer Services, Inc. to provide certain print and mailroom services that were previously performed in-house. Our remaining commitment under this agreement at June 30, 2015 was $47.1 through March 31, 2016 . We have the ability to terminate this agreement upon the occurrence of certain events, subject to early termination fees. Vulnerability from Concentrations Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash equivalents, investment securities, premium receivables and instruments held through hedging activities. All investment securities are managed by professional investment managers within policies authorized by our Board of Directors. Such policies limit the amounts that may be invested in any one issuer and prescribe certain investee company criteria. Concentrations of credit risk with respect to premium receivables are limited due to the large number of employer groups that constitute our customer base in the states in which we conduct business. As of June 30, 2015 , there were no significant concentrations of financial instruments in a single investee, industry or geographic location.

Capital Stock

Capital Stock	6 Months Ended
	Jun. 30, 2015
Capital [Abstract]
Capital Stock	Capital Stock Use of Capital – Dividends and Stock Repurchase Program We regularly review the appropriate use of capital, including acquisitions, common stock and debt security repurchases and dividends to shareholders. The declaration and payment of any dividends or repurchases of our common stock or debt is at the discretion of our Board of Directors and depends upon our financial condition, results of operations, future liquidity needs, regulatory and capital requirements and other factors deemed relevant by our Board of Directors. A summary of the cash dividend activity for the six months ended June 30, 2015 and 2014 is as follows: Declaration Date Record Date Payment Date Cash Dividend per Share Total Six Months Ended June 30, 2015 January 27, 2015 March 10, 2015 March 25, 2015 $0.6250 $166.6 April 28, 2015 June 10, 2015 June 25, 2015 $0.6250 $163.9 Six Months Ended June 30, 2014 January 28, 2014 March 10, 2014 March 25, 2014 $0.4375 $123.4 April 29, 2014 June 10, 2014 June 25, 2014 $0.4375 $120.5 Under our Board of Directors’ authorization, we maintain a common stock repurchase program. On October 2, 2014, the Board of Directors authorized a $5,000.0 increase to the common stock repurchase program. Repurchases may be made from time to time at prevailing market prices, subject to certain restrictions on volume, pricing and timing. The repurchases are effected from time to time in the open market, through negotiated transactions, including accelerated share repurchase agreements, and through plans designed to comply with Rule 10b5-1 under the Securities Exchange Act of 1934, as amended. Our stock repurchase program is discretionary as we are under no obligation to repurchase shares. We repurchase shares under the program when we believe it is a prudent use of capital. The excess cost of the repurchased shares over par value is charged on a pro rata basis to additional paid-in capital and retained earnings. A summary of common stock repurchases for the six months ended June 30, 2015 and 2014 is as follows: Six Months Ended 2015 2014 Shares repurchased 9.7 22.6 Average price per share $ 145.63 $ 92.10 Aggregate cost $ 1,410.6 $ 2,077.2 Authorization remaining at the end of each period $ 4,281.0 $ 1,613.4 Under the common stock repurchase program authorized by our Board of Directors, on February 4, 2014, we entered into an accelerated share repurchase agreement with a counterparty. The agreement provided for the repurchase of a number of our shares, equal to $600.0 , as determined by the volume weighted-average price of our shares during the term of the agreement. In March 2014, we repurchased 6.6 shares under the agreement. The shares repurchased under the agreement are included in the amount disclosed above as shares repurchased during the six months ended June 30, 2014 . During the six months ended June 30, 2015, we entered into a series of call and put options with certain counterparties to repurchase shares of our common stock below the then current market price. We exercised call options that enabled us to repurchase 2.1 shares of our common stock at an average strike price of $135.03 . In order to set the call option strike prices below our market price at inception, we sold 5.3 put options at equal strike prices. During the six months ended June 30, 2015, 2.5 put options expired unexercised. The remaining 2.8 put options have expiration dates in August and September 2015. If the closing market price of our common stock on the expiration dates of the remaining put options is below the put option strike price, we will be required to repurchase up to 2.8 shares of our common stock at the higher contract price. Based on FASB guidance, the value of the call options was recognized as a reduction of shareholders' equity and the value of the put options was recognized as a liability. For additional information regarding the use of capital for debt security repurchases, see Note 9, “Debt.” Equity Units On May 12, 2015, we issued 25.0 Equity Units, pursuant to an underwriting agreement dated May 6, 2015, in an aggregate principal amount of $1,250.0 . For additional information relating to the Equity Units, see Note 9, “Debt.” Stock Incentive Plan s A summary of stock option activity for the six months ended June 30, 2015 is as follows: Number of Shares Weighted- Average Option Price per Share Weighted- Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Outstanding at January 1, 2015 7.3 $ 70.30 Granted 1.2 147.18 Exercised (2.1 ) 67.82 Forfeited or expired (0.1 ) 95.22 Outstanding at June 30, 2015 6.3 85.83 4.73 $ 490.9 Exercisable at June 30, 2015 3.4 66.52 2.73 $ 335.9 A summary of the status of nonvested restricted stock activity, including restricted stock units, for the six months ended June 30, 2015 is as follows: Restricted Stock Shares and Units Weighted- Average Grant Date Fair Value per Share Nonvested at January 1, 2015 3.6 $ 75.63 Granted 0.9 147.10 Vested (1.7 ) 72.31 Forfeited (0.1 ) 96.51 Nonvested at June 30, 2015 2.7 100.45 Fair Value We use a binomial lattice valuation model to estimate the fair value of all stock options granted. For a more detailed discussion of our stock incentive plan fair value methodology, see Note 14, “Capital Stock,” to our audited consolidated financial statements as of and for the year ended December 31, 2014 included in our 2014 Annual Report on Form 10-K. The following weighted-average assumptions were used to estimate the fair values of options granted during the six months ended June 30, 2015 and 2014 : 2015 2014 Risk-free interest rate 1.96 % 2.16 % Volatility factor 31.00 % 35.00 % Quarterly dividend yield 0.425 % 0.500 % Weighted-average expected life (years) 4.00 3.75 The following weighted-average fair values were determined for the six months ended June 30, 2015 and 2014 : 2015 2014 Options granted during the period $ 34.01 $ 22.37 Restricted stock awards granted during the period 147.10 90.17

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	6 Months Ended
	Jun. 30, 2015
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income A reconciliation of the components of accumulated other comprehensive income at June 30, 2015 and 2014 is as follows: 2015 2014 Investments: Gross unrealized gains $ 895.1 $ 1,284.8 Gross unrealized losses (207.0 ) (65.0 ) Net pre-tax unrealized gains 688.1 1,219.8 Deferred tax liability (241.3 ) (425.9 ) Net unrealized gains on investments 446.8 793.9 Non-credit components of other-than-temporary impairments on investments: Unrealized losses (5.7 ) (0.8 ) Deferred tax asset 2.0 0.3 Net unrealized non-credit component of other-than-temporary impairments on investments (3.7 ) (0.5 ) Cash flow hedges: Gross unrealized losses (52.4 ) (47.4 ) Deferred tax asset 18.3 16.6 Net unrealized losses on cash flow hedges (34.1 ) (30.8 ) Defined benefit pension plans: Deferred net actuarial loss (547.8 ) (425.2 ) Deferred prior service credits 1.8 13.7 Deferred tax asset 217.1 164.8 Net unrecognized periodic benefit costs for defined benefit pension plans (328.9 ) (246.7 ) Postretirement benefit plans: Deferred net actuarial loss (203.6 ) (152.4 ) Deferred prior service credits 80.8 82.6 Deferred tax asset 48.7 27.9 Net unrecognized periodic benefit costs for postretirement benefit plans (74.1 ) (41.9 ) Foreign currency translation adjustments: Gross unrealized (losses) gains (8.6 ) 1.6 Deferred tax asset (liability) 3.0 (0.6 ) Net unrealized (losses) gains on foreign currency translation adjustments (5.6 ) 1.0 Accumulated other comprehensive income $ 0.4 $ 475.0 Other comprehensive (loss) income reclassification adjustments for the three months ended June 30, 2015 and 2014 are as follows: 2015 2014 Investments: Net holding (loss) gain on investment securities arising during the period, net of tax benefit (expense) of $109.3 and ($99.4), respectively $ (195.4 ) $ 180.3 Reclassification adjustment for net realized gain on investment securities, net of tax expense of ($24.7) and ($19.2), respectively (45.8 ) (35.7 ) Total reclassification adjustment on investments (241.2 ) 144.6 Non-credit component of other-than-temporary impairments on investments: Non-credit component of other-than-temporary impairments on investments, net of tax benefit of $1.5 and $0.3, respectively (2.8 ) (0.5 ) Cash flow hedges: Holding gain, net of tax expense of ($0.5) and ($0.4), respectively 0.9 0.8 Other: Net change in unrecognized periodic benefit costs for defined benefit pension and postretirement benefit plans, net of tax expense of ($3.3) and ($2.3), respectively 4.9 3.0 Foreign currency translation adjustment, net of tax (expense) benefit of ($0.4) and $0.1, respectively 0.7 (0.3 ) Net (loss) gain recognized in other comprehensive income, net of tax benefit (expense) of $131.3 and ($82.5), respectively $ (237.5 ) $ 147.6 Other comprehensive (loss) income reclassification adjustments for the six months ended June 30, 2015 and 2014 are as follows: 2015 2014 Investments: Net holding (loss) gain on investment securities arising during the period, net of tax benefit (expense) of $53.1 and ($188.5), respectively $ (113.9 ) $ 340.7 Reclassification adjustment for net realized gain on investment securities, net of tax expense of ($36.1) and ($30.0), respectively (66.9 ) (55.8 ) Total reclassification adjustment on investments (180.8 ) 284.9 Non-credit component of other-than-temporary impairments on investments: Non-credit component of other-than-temporary impairments on investments, net of tax expense of ($0.4) and ($0.0), respectively 0.7 — Cash flow hedges: Holding gain, net of tax expense of ($1.0) and ($0.8), respectively 1.8 1.5 Other: Net change in unrecognized periodic benefit costs for defined benefit pension and postretirement benefit plans, net of tax expense of ($6.3) and ($4.2), respectively 9.6 5.9 Foreign currency translation adjustment, net of tax benefit of $1.5 and $0.1, respectively (2.8 ) (0.5 ) Net (loss) gain recognized in other comprehensive income, net of tax benefit (expense) of $83.0 and ($163.4), respectively $ (171.5 ) $ 291.8

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Earnings Per Share	Earnings per Share The denominator for basic and diluted earnings per share for the three and six months ended June 30, 2015 and 2014 is as follows: Three Months Ended Six Months Ended 2015 2014 2015 2014 Denominator for basic earnings per share – weighted-average shares 263.1 276.8 264.8 280.8 Effect of dilutive securities – employee stock options, non-vested restricted stock awards and convertible debentures 11.2 9.2 12.5 8.5 Denominator for diluted earnings per share 274.3 286.0 277.3 289.3 During the three months ended June 30, 2015 and 2014 , weighted-average shares related to certain stock options of 1.2 and 1.4 , respectively, were excluded from the denominator for diluted earnings per share because the stock options were anti-dilutive. During the six months ended June 30, 2015 and 2014 , weighted-average shares related to certain stock options of 0.8 and 1.0 , respectively, were excluded from the denominator for diluted earnings per share because the stock options were anti-dilutive. The Equity Units are potentially dilutive securities but were excluded from the denominator for diluted earnings per share for the three and six months ended June 30, 2015 , as the dilutive stock price threshold was not met. During the three months ended March 31, 2015, we issued approximately 0.9 restricted stock units under our stock incentive plans, 0.4 of which vesting is contingent upon us meeting specified annual earnings targets for the three year period of 2015 through 2017. During the three and six months ended June 30, 2014 , we issued approximately 0.1 and 1.4 , respectively, of restricted stock units under our stock incentive plans, 0.7 of which vesting was contingent upon us meeting specified annual operating gain targets for 2014. The contingent restricted stock units have been excluded from the denominator for diluted earnings per share for the three and six months ended June 30, 2015 and 2014 , respectively, and are included only if and when the contingency is met.

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Segment Information	Segment Information The results of our operations are described through three reportable segments: Commercial and Specialty Business, Government Business and Other, as further described in Note 19, “Segment Information,” to our audited consolidated financial statements as of and for the year ended December 31, 2014 included in our 2014 Annual Report on Form 10-K. Financial data by reportable segment for the three and six months ended June 30, 2015 and 2014 is as follows: Commercial and Specialty Business Government Business Other Total Three months ended June 30, 2015 Operating revenue $ 9,368.2 $ 10,385.0 $ 5.1 $ 19,758.3 Operating gain (loss) 912.0 609.7 (9.6 ) 1,512.1 Three months ended June 30, 2014 Operating revenue $ 9,965.0 $ 8,259.3 $ 5.7 $ 18,230.0 Operating gain (loss) 919.6 313.5 (10.2 ) 1,222.9 Six Months Ended June 30, 2015 Operating revenue $ 18,735.1 $ 19,865.1 $ 9.5 $ 38,609.7 Operating gain (loss) 2,179.0 934.1 (21.7 ) 3,091.4 Six Months Ended June 30, 2014 Operating revenue $ 19,662.5 $ 16,200.6 $ 11.7 $ 35,874.8 Operating gain (loss) 1,805.7 553.1 (17.2 ) 2,341.6 A reconciliation of reportable segments operating revenues, a non-GAAP measure, to the amounts of total revenues included in the consolidated statements of income for the three and six months ended June 30, 2015 and 2014 is as follows: Three Months Ended Six Months Ended 2015 2014 2015 2014 Reportable segments operating revenues $ 19,758.3 $ 18,230.0 $ 38,609.7 $ 35,874.8 Net investment income 186.7 188.5 354.3 372.2 Net realized gains on investments 92.3 65.8 138.8 107.5 Other-than-temporary impairment losses recognized in income (21.8 ) (10.9 ) (35.8 ) (21.7 ) Total revenues $ 20,015.5 $ 18,473.4 $ 39,067.0 $ 36,332.8 A reconciliation of reportable segments operating gain, a non-GAAP measure, to income from continuing operations before income tax expense included in the consolidated statements of income for the three and six months ended June 30, 2015 and 2014 is as follows: Three Months Ended Six Months Ended 2015 2014 2015 2014 Reportable segments operating gain $ 1,512.1 $ 1,222.9 $ 3,091.4 $ 2,341.6 Net investment income 186.7 188.5 354.3 372.2 Net realized gains on investments 92.3 65.8 138.8 107.5 Other-than-temporary impairment losses recognized in income (21.8 ) (10.9 ) (35.8 ) (21.7 ) Interest expense (154.1 ) (145.6 ) (308.5 ) (291.8 ) Amortization of other intangible assets (60.1 ) (54.0 ) (112.6 ) (108.0 ) Gain (loss) on extinguishment of debt 2.9 (3.0 ) (0.5 ) (6.0 ) Income from continuing operations before income tax expense $ 1,558.0 $ 1,263.7 $ 3,127.1 $ 2,393.8

Basis of Presentation and Signf

Basis of Presentation and Signficant Accounting Policies	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation: The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial reporting. Accordingly, they do not include all of the information and footnotes required by GAAP for annual financial statements. We have omitted certain footnote disclosures that would substantially duplicate the disclosures in our 2014 Annual Report on Form 10-K, unless the information contained in those disclosures materially changed or is required by GAAP. Unless otherwise specified, all financial information presented in the accompanying consolidated financial statements and in the notes to consolidated financial statements relates only to our continuing operations, other than cash flows presented on the consolidated statements of cash flows. In the opinion of management, all adjustments, including normal recurring adjustments, necessary for a fair statement of the consolidated financial statements as of and for the three and six months ended June 30, 2015 and 2014 have been recorded. The results of operations for the three and six months ended June 30, 2015 are not necessarily indicative of the results that may be expected for the full year ending December 31, 2015 . These unaudited consolidated financial statements should be read in conjunction with our audited consolidated financial statements for the year ended December 31, 2014 included in our 2014 Annual Report on Form 10-K.
Foreign Currency	Certain of our subsidiaries operate outside of the United States and have functional currencies other than the U.S. dollar, or USD. We translate the assets and liabilities of those subsidiaries to USD using the exchange rate in effect at the end of the period. We translate the revenues and expenses of those subsidiaries to USD using the average exchange rates in effect during the period. The net effect of these translation adjustments is included in “Foreign currency translation adjustments” in our consolidated statements of comprehensive income.
Recently Adopted Accounting Guidance	Recently Adopted Accounting Guidance: In June 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update No. 2014-11, Transfers and Servicing (Topic 860): Repurchase-to-Maturity Transactions, Repurchase Financings, and Disclosures, or ASU 2014-11 . This amendment requires repurchase-to-maturity transactions to be accounted for as secured borrowings and eliminates previous guidance for repurchase financings. The amendment also expands the disclosure requirements related to certain transactions accounted for as secured borrowings and certain transfers accounted for as sales when the transferor also retains substantially all of the exposure to the economic return on the transferred financial assets throughout the term of the transaction. The amendments related to the accounting of, and disclosure requirements for, certain transactions accounted for as a sale became effective as of January 1, 2015 and did not have an impact on our consolidated financial position, results of operations, cash flows or disclosures. The new disclosure requirements for repurchase agreements, securities lending transactions and repurchase-to-maturity transactions accounted for as secured borrowings became effective as of April 1, 2015. See Note 5, "Investments - Securities Lending Programs, " for additional disclosure information related to the adoption of ASU 2014-11. In April 2015, the FASB issued Accounting Standards Update No. 2015-03, Interest - Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs , or ASU 2015-03. ASU 2015-03 amends current presentation guidance by requiring that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. Prior to the issuance of ASU 2015-03, debt issuance costs were required to be presented as an asset in the balance sheet. We adopted the provisions of ASU 2015-03 upon issuance and prior period amounts have been reclassified to conform to the current period presentation. As of December 31, 2014, $0.7 of debt issuance costs were reclassified in the consolidated balance sheet from other current assets to current portion of long-term debt and $ 107.6 was reclassified from other noncurrent assets to long-term debt, less current portion. The adoption of ASU 2015-03 did not impact our consolidated financial position, results of operations or cash flows.
Recent Accounting Guidance Not Yet Adopted	Recent Accounting Guidance Not Yet Adopted: In May 2015, the FASB issued Accounting Standards Update No. 2015-09, Financial Services—Insurance (Topic 944): Disclosures about Short-Duration Contracts, or ASU 2015-09. This amendment requires new and expanded disclosures in interim and annual reporting periods related to the liability for unpaid claims and claim adjustment expenses for short-duration insurance contracts. ASU 2015-09 is effective for annual reporting periods beginning after December 15, 2015, and interim reporting periods within annual reporting periods beginning after December 15, 2016. The adoption of ASU 2015-03 will not impact our consolidated financial position, results of operations or cash flows. In April 2015, the FASB issued Accounting Standards Update No. 2015-05, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement , or ASU 2015-05. This amendment provides guidance to help entities determine whether a cloud computing arrangement contains a software license that should be accounted for as internal-use software or as a service contract. ASU 2015-05 is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted. Upon adoption, an entity has the option to apply the provisions of ASU 2015-05 either prospectively to all arrangements entered into or materially modified, or retrospectively. We are currently evaluating the effects the adoption of ASU 2015-05 will have upon our consolidated financial position, results of operations or cash flows. In February 2015, the FASB issued Accounting Standards Update No. 2015-02, Consolidation (Topic 810): Amendments to the Consolidation Analysis , or ASU 2015-02. ASU 2015-02 amends current consolidation guidance by modifying the evaluation of whether limited partnerships and similar legal entities are variable interest entities or voting interest entities, eliminating the presumption that a general partner should consolidate a limited partnership, and affects the consolidation analysis of reporting entities that are involved with variable interest entities. ASU No. 2015-02 is effective for interim and annual reporting periods beginning after December 15, 2015, with early adoption permitted. All legal entities are subject to reevaluation under the revised consolidation model. The adoption of ASU 2015-02 is not expected to have a material impact on our consolidated financial position, results of operations or cash flows. There were no other new accounting pronouncements that were issued or became effective since the issuance of our 2014 Annual Report on Form 10-K that had, or are expected to have, a material impact on our consolidated financial position, results of operations or cash flows.

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2015
Investments [Abstract]
Current and Long-Term Investments, Available-For-Sale	A summary of current and long-term investments, available-for-sale, at June 30, 2015 and December 31, 2014 is as follows: Non-Credit Component of Other-Than- Cost or Gross Gross Unrealized Losses Estimated Less than 12 Months 12 Months or Greater June 30, 2015 Fixed maturity securities: United States Government securities $ 323.9 $ 2.8 $ (0.8 ) $ — $ 325.9 $ — Government sponsored securities 87.7 0.8 (0.1 ) (0.2 ) 88.2 — States, municipalities and political subdivisions, tax-exempt 5,782.6 212.2 (24.8 ) (5.2 ) 5,964.8 — Corporate securities 9,380.6 119.8 (112.0 ) (23.2 ) 9,365.2 (5.8 ) Options embedded in convertible debt securities 0.8 — — — 0.8 — Residential mortgage-backed securities 1,895.2 52.4 (7.1 ) (7.5 ) 1,933.0 — Commercial mortgage-backed securities 432.3 4.0 (1.1 ) (0.2 ) 435.0 — Other debt securities 732.1 7.2 (0.9 ) (1.1 ) 737.3 — Total fixed maturity securities 18,635.2 399.2 (146.8 ) (37.4 ) 18,850.2 $ (5.8 ) Equity securities 1,264.0 495.9 (22.8 ) — 1,737.1 Total investments, available-for-sale $ 19,899.2 $ 895.1 $ (169.6 ) $ (37.4 ) $ 20,587.3 December 31, 2014 Fixed maturity securities: United States Government securities $ 315.7 $ 4.6 $ (0.3 ) $ — $ 320.0 $ — Government sponsored securities 94.6 0.8 — (0.4 ) 95.0 — States, municipalities and political subdivisions, tax-exempt 5,451.4 287.0 (1.8 ) (3.0 ) 5,733.6 — Corporate securities 8,335.9 162.9 (123.1 ) (43.2 ) 8,332.5 (6.8 ) Options embedded in convertible debt securities 98.7 — — — 98.7 — Residential mortgage-backed securities 2,099.7 68.9 (1.0 ) (8.6 ) 2,159.0 — Commercial mortgage-backed securities 504.8 6.1 (0.6 ) (0.4 ) 509.9 — Other debt securities 720.3 6.1 (1.7 ) (1.6 ) 723.1 — Total fixed maturity securities 17,621.1 536.4 (128.5 ) (57.2 ) 17,971.8 $ (6.8 ) Equity securities 1,330.7 618.5 (11.1 ) — 1,938.1 Total investments, available-for-sale $ 18,951.8 $ 1,154.9 $ (139.6 ) $ (57.2 ) $ 19,909.9
Aggregate Fair Value and Gross Unrealized Loss of Fixed Maturity Securities and Equity Securities in an Unrealized Loss Position	The following tables summarize for available-for-sale fixed maturity securities and available-for-sale equity securities in an unrealized loss position at June 30, 2015 and December 31, 2014 , the aggregate fair value and gross unrealized loss by length of time those securities have been continuously in an unrealized loss position: Less than 12 Months 12 Months or Greater (Securities are whole amounts) Number of Securities Estimated Fair Value Gross Unrealized Loss Number of Securities Estimated Fair Value Gross Unrealized Loss June 30, 2015 Fixed maturity securities: United States Government securities 18 $ 69.1 $ (0.8 ) 2 $ 0.9 $ — Government sponsored securities 12 19.0 (0.1 ) 10 20.7 (0.2 ) States, municipalities and political subdivisions, tax-exempt 557 1,502.7 (24.8 ) 39 71.1 (5.2 ) Corporate securities 1,895 4,702.7 (112.0 ) 277 397.0 (23.2 ) Residential mortgage-backed securities 277 573.7 (7.1 ) 114 195.2 (7.5 ) Commercial mortgage-backed securities 49 135.8 (1.1 ) 13 28.0 (0.2 ) Other debt securities 56 183.7 (0.9 ) 21 56.8 (1.1 ) Total fixed maturity securities 2,864 7,186.7 (146.8 ) 476 769.7 (37.4 ) Equity securities 554 360.5 (22.8 ) — — — Total fixed maturity and equity securities 3,418 $ 7,547.2 $ (169.6 ) 476 $ 769.7 $ (37.4 ) December 31, 2014 Fixed maturity securities: United States Government securities 17 $ 145.3 $ (0.3 ) 2 $ 0.9 $ — Government sponsored securities 2 0.3 — 16 29.3 (0.4 ) States, municipalities and political subdivisions, tax-exempt 136 315.6 (1.8 ) 80 174.3 (3.0 ) Corporate securities 1,802 3,213.3 (123.1 ) 314 514.6 (43.2 ) Residential mortgage-backed securities 78 155.0 (1.0 ) 186 398.3 (8.6 ) Commercial mortgage-backed securities 43 156.2 (0.6 ) 10 33.2 (0.4 ) Other debt securities 79 270.6 (1.7 ) 21 65.0 (1.6 ) Total fixed maturity securities 2,157 4,256.3 (128.5 ) 629 1,215.6 (57.2 ) Equity securities 407 125.4 (11.1 ) — — — Total fixed maturity and equity securities 2,564 $ 4,381.7 $ (139.6 ) 629 $ 1,215.6 $ (57.2 )
Amortized Cost and Fair Value of Fixed Maturity Securities, By Contractual Maturity	The amortized cost and fair value of available-for-sale fixed maturity securities at June 30, 2015 , by contractual maturity, are shown below. Expected maturities may differ from contractual maturities because the issuers of the securities may have the right to prepay obligations. Amortized Cost Estimated Fair Value Due in one year or less $ 425.4 $ 428.2 Due after one year through five years 4,691.9 4,740.8 Due after five years through ten years 5,427.2 5,510.2 Due after ten years 5,763.2 5,803.0 Mortgage-backed securities 2,327.5 2,368.0 Total available-for-sale fixed maturity securities $ 18,635.2 $ 18,850.2
Proceeds and Realized Gains Losses from Investments	Proceeds from fixed maturity securities, equity securities and other invested assets and the related gross realized gains and gross realized losses for the three and six months ended June 30, 2015 and 2014 are as follows: Three Months Ended Six Months Ended 2015 2014 2015 2014 Proceeds $ 3,234.8 $ 2,560.0 $ 6,160.7 $ 4,961.4 Gross realized gains 148.4 106.2 282.1 189.1 Gross realized losses (56.1 ) (40.4 ) (143.3 ) (81.6 )
Securities Lending Programs	The remaining contractual maturity of our securities lending agreements at June 30, 2015 is as follows: Overnight and Continuous Less than 30 days 30-90 days Greater Than 90 days Total Securities lending transactions United States Government securities $ 100.3 $ — $ 14.2 $ 57.4 $ 171.9 Corporate securities 747.2 — — — 747.2 Equity securities 418.7 — — — 418.7 Other debt securities 380.4 — — — 380.4 Total $ 1,646.6 $ — $ 14.2 $ 57.4 $ 1,718.2

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements By Level For Assets Measured At Fair Value On A Recurring Basis	A summary of fair value measurements by level for assets and liabilities measured at fair value on a recurring basis at June 30, 2015 and December 31, 2014 is as follows: Level I Level II Level III Total June 30, 2015 Assets: Cash equivalents $ 686.4 $ — $ — $ 686.4 Investments available-for-sale: Fixed maturity securities: United States Government securities 325.9 — — 325.9 Government sponsored securities — 88.2 — 88.2 States, municipalities and political subdivisions, tax-exempt — 5,964.8 — 5,964.8 Corporate securities 212.1 8,960.7 192.4 9,365.2 Options embedded in convertible debt securities — 0.8 — 0.8 Residential mortgage-backed securities — 1,933.0 — 1,933.0 Commercial mortgage-backed securities — 432.2 2.8 435.0 Other debt securities 81.5 649.5 6.3 737.3 Total fixed maturity securities 619.5 18,029.2 201.5 18,850.2 Equity securities 1,558.2 124.8 54.1 1,737.1 Other invested assets, current 23.4 — — 23.4 Securities lending collateral 943.1 775.2 — 1,718.3 Derivatives excluding embedded options (reported with other assets) — 218.0 — 218.0 Total assets $ 3,830.6 $ 19,147.2 $ 255.6 $ 23,233.4 Liabilities: Derivatives excluding embedded options (reported with other liabilities) $ — $ (215.1 ) $ — $ (215.1 ) Total liabilities $ — $ (215.1 ) $ — $ (215.1 ) December 31, 2014 Assets: Cash equivalents $ 573.2 $ — $ — $ 573.2 Investments available-for-sale: Fixed maturity securities: United States Government securities 320.0 — — 320.0 Government sponsored securities — 95.0 — 95.0 States, municipalities and political subdivisions, tax-exempt — 5,733.6 — 5,733.6 Corporate securities 7.1 8,180.8 144.6 8,332.5 Options embedded in convertible debt securities — 98.7 — 98.7 Residential mortgage-backed securities — 2,159.0 — 2,159.0 Commercial mortgage-backed securities — 506.6 3.3 509.9 Other debt securities 89.2 627.3 6.6 723.1 Total fixed maturity securities 416.3 17,401.0 154.5 17,971.8 Equity securities 1,696.9 192.9 48.3 1,938.1 Other invested assets, current 20.2 — — 20.2 Securities lending collateral 808.3 706.9 — 1,515.2 Derivatives excluding embedded options (reported with other assets) — 224.8 — 224.8 Total assets $ 3,514.9 $ 18,525.6 $ 202.8 $ 22,243.3 Liabilities: Derivatives excluding embedded options (reported with other liabilities) $ — $ (260.4 ) $ — $ (260.4 ) Total liabilities $ — $ (260.4 ) $ — $ (260.4 )
Reconciliation Of The Beginning And Ending Balances Of Assets Measured At Fair Value On A Recurring Basis Using Level III Inputs	Corporate Securities Commercial Mortgage- backed Securities Other Debt Securities Equity Securities Long-term Receivable Total Three months ended June 30, 2015 Beginning balance at April 1, 2015 $ 165.5 $ 3.2 $ 2.6 $ 51.8 $ — $ 223.1 Total gains (losses): Recognized in net income (0.8 ) — — (0.4 ) — (1.2 ) Recognized in accumulated other comprehensive income 1.4 — — (0.4 ) — 1.0 Purchases 57.2 — 3.7 4.3 — 65.2 Sales (4.1 ) — — (1.2 ) — (5.3 ) Settlements (11.3 ) (0.4 ) — — — (11.7 ) Transfers into Level III 4.2 — — — — 4.2 Transfers out of Level III (19.7 ) — — — — (19.7 ) Ending balance at June 30, 2015 $ 192.4 $ 2.8 $ 6.3 $ 54.1 $ — $ 255.6 Change in unrealized losses included in net income related to assets still held for the three months ended June 30, 2015 $ — $ — $ — $ (0.2 ) $ — $ (0.2 ) Three months ended June 30, 2014 Beginning balance at April 1, 2014 $ 114.0 $ 3.1 $ 14.8 $ 43.2 $ 21.6 $ 196.7 Total gains (losses): Recognized in net income (3.0 ) — — (0.4 ) 10.6 7.2 Recognized in accumulated other comprehensive income 9.6 — 0.1 7.1 — 16.8 Purchases 11.6 3.6 3.0 1.7 — 19.9 Sales (4.5 ) — — (8.5 ) — (13.0 ) Settlements (1.5 ) — (0.1 ) — — (1.6 ) Transfers into Level III 24.2 — — — — 24.2 Transfers out of Level III — (3.1 ) — — — (3.1 ) Ending balance at June 30, 2014 $ 150.4 $ 3.6 $ 17.8 $ 43.1 $ 32.2 $ 247.1 Change in unrealized losses included in net income related to assets still held for the three months ended June 30, 2014 $ (3.6 ) $ — $ — $ (0.4 ) $ — $ (4.0 ) A reconciliation of the beginning and ending balances of assets measured at fair value on a recurring basis using Level III inputs for the six months ended June 30, 2015 and 2014 is as follows: Corporate Securities Commercial Mortgage- backed Securities Other Debt Securities Equity Securities Long-term Receivable Total Six Months Ended June 30, 2015 Beginning balance at January 1, 2015 $ 144.6 $ 3.3 $ 6.6 $ 48.3 $ — $ 202.8 Total gains (losses): Recognized in net income (1.0 ) — 0.2 (1.2 ) — (2.0 ) Recognized in accumulated other comprehensive income 3.0 — (0.2 ) 0.9 — 3.7 Purchases 89.6 — 3.7 11.8 — 105.1 Sales (4.1 ) — (0.9 ) (5.7 ) — (10.7 ) Settlements (24.9 ) (0.5 ) (0.1 ) — — (25.5 ) Transfers into Level III 4.9 — — — — 4.9 Transfers out of Level III (19.7 ) — (3.0 ) — — (22.7 ) Ending balance at June 30, 2015 $ 192.4 $ 2.8 $ 6.3 $ 54.1 $ — $ 255.6 Change in unrealized losses included in net income related to assets still held for the six months ended June 30, 2015 $ (0.6 ) $ — $ — $ (1.0 ) $ — $ (1.6 ) Six Months Ended June 30, 2014 Beginning balance at January 1, 2014 $ 115.2 $ 6.5 $ 14.8 $ 41.4 $ — $ 177.9 Total gains (losses): Recognized in net income (6.3 ) — — (0.7 ) 32.2 25.2 Recognized in accumulated other comprehensive income 12.7 — 0.3 1.3 — 14.3 Purchases 20.9 3.6 3.0 10.7 — 38.2 Sales (6.2 ) — — (9.6 ) — (15.8 ) Settlements (3.6 ) (3.4 ) (0.3 ) — — (7.3 ) Transfers into Level III 24.2 — — — — 24.2 Transfers out of Level III (6.5 ) (3.1 ) — — — (9.6 ) Ending balance at June 30, 2014 $ 150.4 $ 3.6 $ 17.8 $ 43.1 $ 32.2 $ 247.1 Change in unrealized losses included in net income related to assets still held for the six months ended June 30, 2014 $ (7.6 ) $ — $ — $ (0.7 ) $ — $ (8.3 )
Carrying And Fair Values By Level Of Financial Instruments Not Recorded At Fair Value On Consolidated Balance Sheet	A summary of the estimated fair values by level of each class of financial instrument that is recorded at its carrying value on our consolidated balance sheets at June 30, 2015 and December 31, 2014 are as follows: Carrying Value Estimated Fair Value Level I Level II Level III Total June 30, 2015 Assets: Other invested assets, long-term $ 1,803.3 $ — $ — $ 1,803.3 $ 1,803.3 Liabilities: Debt: Short-term borrowings 540.0 — 540.0 — 540.0 Commercial paper 697.4 — 697.4 — 697.4 Notes 14,926.3 — 15,148.6 — 15,148.6 Convertible debentures 469.6 — 1,608.4 — 1,608.4 December 31, 2014 Assets: Other invested assets, long-term $ 1,695.9 $ — $ — $ 1,695.9 $ 1,695.9 Liabilities: Debt: Short-term borrowings 400.0 — 400.0 — 400.0 Notes 13,687.5 — 14,794.8 — 14,794.8 Convertible debentures 956.4 — 2,581.9 — 2,581.9

Retirement Benefits (Tables)

Retirement Benefits (Tables)	6 Months Ended
	Jun. 30, 2015
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Components of Net Periodic Benefit (Credit) Costs	The components of net periodic (credit) benefit cost included in the consolidated statements of income for the three months ended June 30, 2015 and 2014 are as follows: Pension Benefits Other Benefits 2015 2014 2015 2014 Service cost $ 3.3 $ 3.2 $ 0.6 $ 0.8 Interest cost 17.1 18.5 5.8 6.5 Expected return on assets (35.9 ) (34.3 ) (5.9 ) (5.9 ) Recognized actuarial loss 6.5 5.2 3.8 2.4 Settlement loss 1.7 1.4 — — Amortization of prior service credit (0.2 ) (0.2 ) (3.6 ) (3.6 ) Net periodic (credit) benefit cost $ (7.5 ) $ (6.2 ) $ 0.7 $ 0.2 The components of net periodic (credit) benefit cost included in the consolidated statements of income for the six months ended June 30, 2015 and 2014 are as follows: Pension Benefits Other Benefits 2015 2014 2015 2014 Service cost $ 6.6 $ 6.5 $ 1.1 $ 1.6 Interest cost 34.1 37.0 11.7 13.1 Expected return on assets (71.6 ) (68.7 ) (11.8 ) (11.7 ) Recognized actuarial loss 12.9 10.5 7.6 4.7 Settlement loss 3.0 2.5 — — Amortization of prior service credit (0.4 ) (0.4 ) (7.2 ) (7.2 ) Net periodic (credit) benefit cost $ (15.4 ) $ (12.6 ) $ 1.4 $ 0.5

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Carrying Value Of Long-Term Debt	The carrying value of long-term debt at June 30, 2015 and December 31, 2014 consists of the following: June 30, 2015 December 31, 2014 Senior unsecured notes: 1.250%, due 2015 $ 624.9 $ 624.3 2.375%, due 2017 400.0 398.9 5.875%, due 2017 527.2 526.7 1.875%, due 2018 621.6 616.4 2.300%, due 2018 645.1 644.3 2.250%, due 2019 843.0 842.1 7.000%, due 2019 438.7 438.5 4.350%, due 2020 698.8 695.3 3.700%, due 2021 695.9 695.6 3.125%, due 2022 842.2 841.6 3.300%, due 2023 991.8 991.2 3.500%, due 2024 790.4 789.8 5.950%, due 2034 444.4 444.4 5.850%, due 2036 767.8 767.7 6.375%, due 2037 639.5 639.3 5.800%, due 2040 193.7 206.4 4.625%, due 2042 885.6 885.4 4.650%, due 2043 985.2 985.0 4.650%, due 2044 790.3 790.1 5.100%, due 2044 593.2 593.1 4.850%, due 2054 246.6 246.5 Remarketable subordinated notes: 1.900%, due 2028 1,235.5 — Surplus notes: 9.000%, due 2027 24.9 24.9 Senior convertible debentures: 2.750%, due 2042 469.6 956.4 Variable rate debt: Commercial paper program 697.4 — Total long-term debt 16,093.3 14,643.9 Current portion of long-term debt (624.9 ) (624.3 ) Long-term debt, less current portion $ 15,468.4 $ 14,019.6
Convertible Debenture Terms	The following table summarizes at June 30, 2015 the related balances, conversion rate and conversion price of the Debentures: Outstanding principal amount $ 733.0 Unamortized debt discount $ 254.7 Net debt carrying amount $ 469.6 Equity component carrying amount $ 265.7 Conversion rate (shares of common stock per $1,000 of principal amount) 13.4231 Effective conversion price (per $1,000 of principal amount) $ 74.4977

Capital Stock (Tables)

Capital Stock (Tables)	6 Months Ended
	Jun. 30, 2015
Capital [Abstract]
Summary of Cash Dividend Activity	A summary of the cash dividend activity for the six months ended June 30, 2015 and 2014 is as follows: Declaration Date Record Date Payment Date Cash Dividend per Share Total Six Months Ended June 30, 2015 January 27, 2015 March 10, 2015 March 25, 2015 $0.6250 $166.6 April 28, 2015 June 10, 2015 June 25, 2015 $0.6250 $163.9 Six Months Ended June 30, 2014 January 28, 2014 March 10, 2014 March 25, 2014 $0.4375 $123.4 April 29, 2014 June 10, 2014 June 25, 2014 $0.4375 $120.5
Summary of Share Repurchases	A summary of common stock repurchases for the six months ended June 30, 2015 and 2014 is as follows: Six Months Ended 2015 2014 Shares repurchased 9.7 22.6 Average price per share $ 145.63 $ 92.10 Aggregate cost $ 1,410.6 $ 2,077.2 Authorization remaining at the end of each period $ 4,281.0 $ 1,613.4
Summary of Stock Option Activity	A summary of stock option activity for the six months ended June 30, 2015 is as follows: Number of Shares Weighted- Average Option Price per Share Weighted- Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Outstanding at January 1, 2015 7.3 $ 70.30 Granted 1.2 147.18 Exercised (2.1 ) 67.82 Forfeited or expired (0.1 ) 95.22 Outstanding at June 30, 2015 6.3 85.83 4.73 $ 490.9 Exercisable at June 30, 2015 3.4 66.52 2.73 $ 335.9
Summary of Nonvested Restricted Stock Activity Including Restricted Stock Units	A summary of the status of nonvested restricted stock activity, including restricted stock units, for the six months ended June 30, 2015 is as follows: Restricted Stock Shares and Units Weighted- Average Grant Date Fair Value per Share Nonvested at January 1, 2015 3.6 $ 75.63 Granted 0.9 147.10 Vested (1.7 ) 72.31 Forfeited (0.1 ) 96.51 Nonvested at June 30, 2015 2.7 100.45
Summary of Weighted-Average Assumptions Used to Estimate the Fair Value of Options Granted During the Periods	The following weighted-average assumptions were used to estimate the fair values of options granted during the six months ended June 30, 2015 and 2014 : 2015 2014 Risk-free interest rate 1.96 % 2.16 % Volatility factor 31.00 % 35.00 % Quarterly dividend yield 0.425 % 0.500 % Weighted-average expected life (years) 4.00 3.75
Schedule of Weighted-Average Fair Values Determined for the Periods	The following weighted-average fair values were determined for the six months ended June 30, 2015 and 2014 : 2015 2014 Options granted during the period $ 34.01 $ 22.37 Restricted stock awards granted during the period 147.10 90.17

Accumulated Other Comprehensi28

Accumulated Other Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2015
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Components Of Accumulated Other Comprehensive Income	A reconciliation of the components of accumulated other comprehensive income at June 30, 2015 and 2014 is as follows: 2015 2014 Investments: Gross unrealized gains $ 895.1 $ 1,284.8 Gross unrealized losses (207.0 ) (65.0 ) Net pre-tax unrealized gains 688.1 1,219.8 Deferred tax liability (241.3 ) (425.9 ) Net unrealized gains on investments 446.8 793.9 Non-credit components of other-than-temporary impairments on investments: Unrealized losses (5.7 ) (0.8 ) Deferred tax asset 2.0 0.3 Net unrealized non-credit component of other-than-temporary impairments on investments (3.7 ) (0.5 ) Cash flow hedges: Gross unrealized losses (52.4 ) (47.4 ) Deferred tax asset 18.3 16.6 Net unrealized losses on cash flow hedges (34.1 ) (30.8 ) Defined benefit pension plans: Deferred net actuarial loss (547.8 ) (425.2 ) Deferred prior service credits 1.8 13.7 Deferred tax asset 217.1 164.8 Net unrecognized periodic benefit costs for defined benefit pension plans (328.9 ) (246.7 ) Postretirement benefit plans: Deferred net actuarial loss (203.6 ) (152.4 ) Deferred prior service credits 80.8 82.6 Deferred tax asset 48.7 27.9 Net unrecognized periodic benefit costs for postretirement benefit plans (74.1 ) (41.9 ) Foreign currency translation adjustments: Gross unrealized (losses) gains (8.6 ) 1.6 Deferred tax asset (liability) 3.0 (0.6 ) Net unrealized (losses) gains on foreign currency translation adjustments (5.6 ) 1.0 Accumulated other comprehensive income $ 0.4 $ 475.0
Other Comprehensive Income Reclassification Adjustments	2015 2014 Investments: Net holding (loss) gain on investment securities arising during the period, net of tax benefit (expense) of $109.3 and ($99.4), respectively $ (195.4 ) $ 180.3 Reclassification adjustment for net realized gain on investment securities, net of tax expense of ($24.7) and ($19.2), respectively (45.8 ) (35.7 ) Total reclassification adjustment on investments (241.2 ) 144.6 Non-credit component of other-than-temporary impairments on investments: Non-credit component of other-than-temporary impairments on investments, net of tax benefit of $1.5 and $0.3, respectively (2.8 ) (0.5 ) Cash flow hedges: Holding gain, net of tax expense of ($0.5) and ($0.4), respectively 0.9 0.8 Other: Net change in unrecognized periodic benefit costs for defined benefit pension and postretirement benefit plans, net of tax expense of ($3.3) and ($2.3), respectively 4.9 3.0 Foreign currency translation adjustment, net of tax (expense) benefit of ($0.4) and $0.1, respectively 0.7 (0.3 ) Net (loss) gain recognized in other comprehensive income, net of tax benefit (expense) of $131.3 and ($82.5), respectively $ (237.5 ) $ 147.6 Other comprehensive (loss) income reclassification adjustments for the six months ended June 30, 2015 and 2014 are as follows: 2015 2014 Investments: Net holding (loss) gain on investment securities arising during the period, net of tax benefit (expense) of $53.1 and ($188.5), respectively $ (113.9 ) $ 340.7 Reclassification adjustment for net realized gain on investment securities, net of tax expense of ($36.1) and ($30.0), respectively (66.9 ) (55.8 ) Total reclassification adjustment on investments (180.8 ) 284.9 Non-credit component of other-than-temporary impairments on investments: Non-credit component of other-than-temporary impairments on investments, net of tax expense of ($0.4) and ($0.0), respectively 0.7 — Cash flow hedges: Holding gain, net of tax expense of ($1.0) and ($0.8), respectively 1.8 1.5 Other: Net change in unrecognized periodic benefit costs for defined benefit pension and postretirement benefit plans, net of tax expense of ($6.3) and ($4.2), respectively 9.6 5.9 Foreign currency translation adjustment, net of tax benefit of $1.5 and $0.1, respectively (2.8 ) (0.5 ) Net (loss) gain recognized in other comprehensive income, net of tax benefit (expense) of $83.0 and ($163.4), respectively $ (171.5 ) $ 291.8

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2015
Earnings Per Share [Abstract]
Denominator for Basic and Diluted Earnings Per Share	The denominator for basic and diluted earnings per share for the three and six months ended June 30, 2015 and 2014 is as follows: Three Months Ended Six Months Ended 2015 2014 2015 2014 Denominator for basic earnings per share – weighted-average shares 263.1 276.8 264.8 280.8 Effect of dilutive securities – employee stock options, non-vested restricted stock awards and convertible debentures 11.2 9.2 12.5 8.5 Denominator for diluted earnings per share 274.3 286.0 277.3 289.3

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Financial Data By Reportable Segment	Financial data by reportable segment for the three and six months ended June 30, 2015 and 2014 is as follows: Commercial and Specialty Business Government Business Other Total Three months ended June 30, 2015 Operating revenue $ 9,368.2 $ 10,385.0 $ 5.1 $ 19,758.3 Operating gain (loss) 912.0 609.7 (9.6 ) 1,512.1 Three months ended June 30, 2014 Operating revenue $ 9,965.0 $ 8,259.3 $ 5.7 $ 18,230.0 Operating gain (loss) 919.6 313.5 (10.2 ) 1,222.9 Six Months Ended June 30, 2015 Operating revenue $ 18,735.1 $ 19,865.1 $ 9.5 $ 38,609.7 Operating gain (loss) 2,179.0 934.1 (21.7 ) 3,091.4 Six Months Ended June 30, 2014 Operating revenue $ 19,662.5 $ 16,200.6 $ 11.7 $ 35,874.8 Operating gain (loss) 1,805.7 553.1 (17.2 ) 2,341.6
Reconciliation Of Reportable Segments Operating Revenues To Total Revenues Reported In The Consolidated Statements Of Income	A reconciliation of reportable segments operating revenues, a non-GAAP measure, to the amounts of total revenues included in the consolidated statements of income for the three and six months ended June 30, 2015 and 2014 is as follows: Three Months Ended Six Months Ended 2015 2014 2015 2014 Reportable segments operating revenues $ 19,758.3 $ 18,230.0 $ 38,609.7 $ 35,874.8 Net investment income 186.7 188.5 354.3 372.2 Net realized gains on investments 92.3 65.8 138.8 107.5 Other-than-temporary impairment losses recognized in income (21.8 ) (10.9 ) (35.8 ) (21.7 ) Total revenues $ 20,015.5 $ 18,473.4 $ 39,067.0 $ 36,332.8
Reconciliation Of Reportable Segments Operating Gain To Income Before Income Tax Expense Included In The Consolidated Statements Of Income	A reconciliation of reportable segments operating gain, a non-GAAP measure, to income from continuing operations before income tax expense included in the consolidated statements of income for the three and six months ended June 30, 2015 and 2014 is as follows: Three Months Ended Six Months Ended 2015 2014 2015 2014 Reportable segments operating gain $ 1,512.1 $ 1,222.9 $ 3,091.4 $ 2,341.6 Net investment income 186.7 188.5 354.3 372.2 Net realized gains on investments 92.3 65.8 138.8 107.5 Other-than-temporary impairment losses recognized in income (21.8 ) (10.9 ) (35.8 ) (21.7 ) Interest expense (154.1 ) (145.6 ) (308.5 ) (291.8 ) Amortization of other intangible assets (60.1 ) (54.0 ) (112.6 ) (108.0 ) Gain (loss) on extinguishment of debt 2.9 (3.0 ) (0.5 ) (6.0 ) Income from continuing operations before income tax expense $ 1,558.0 $ 1,263.7 $ 3,127.1 $ 2,393.8

Organization (Details)

Organization (Details) - Jun. 30, 2015 medical_member in Millions	medical_membercountystates
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of medical membership members | medical_member	38.5
Number of counties in the Kansas City area the Company does not serve	30
Number of counties in the New York City metropolitan area the Company serves as independent licensee	10
Number of states in which the Company is licensed to conduct insurance operations | states	50

Subsequent Event Subsequent Eve

Subsequent Event Subsequent Event (Details) - Jul. 23, 2015 $ / shares in Units, $ in Millions	USD ($)shares$ / shares
Subsequent Event [Line Items]
Number of countries and jurisdictions In which acquiree operates	30
Merger agreement, monetary cost per share consideration | $ / shares	$ 103.40
Merger agreement, per share consideration of acquirer stock to be exchanged for acquiree stock | shares	0.5152
Merger agreement, approximate purchase price, gross	$ 53,000
Merger agreement, approximate pro forma equity ownership of acquirer shareholders	67.00%
Merger agreement, approximate pro forma equity ownership of acquiree shareholders	33.00%
Bridge term loan credit facility, maximum borrowing capacity	$ 26,500

Basis of Presentation and Sig33

Basis of Presentation and Signficant Accounting Policies Adoption of New Accounting Pronouncement (Details)	Dec. 31, 2014USD ($)
New Accounting Pronouncement, Early Adoption [Line Items]
Unamortized Debt Issuance Cost Reclassified, Current	$ 0.7
Unamortized Debt Issuance Cost Reclassified, Noncurrent	$ 107.6

Business Acquisition and Dive34

Business Acquisition and Divestiture Business Acquisition and Divestiture (Assets Liabilities Acquired) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 17,541.7	$ 17,082
Customer Relationships [Member] | Simply Healthcare [Member] | Minimum [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	2 years
Customer Relationships [Member] | Simply Healthcare [Member] | Maximum [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	4 years
Government Business [Member] | Simply Healthcare [Member]
Business Acquisition [Line Items]
Other Intangible Assets	$ 430
Goodwill	$ 459.7

Investments (Current And Long-T

Investments (Current And Long-Term Investments, Available-For-Sale) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Investments [Line Items]
Cost or Amortized Cost	$ 19,899.2	$ 18,951.8
Gross Unrealized Gains	895.1	1,154.9
Gross unrealized loss, less than 12 months	(169.6)	(139.6)
Gross unrealized loss, 12 months or greater	(37.4)	(57.2)
Available-for-sale Securities	20,587.3	19,909.9
Equity Securities [Member]
Investments [Line Items]
Cost or Amortized Cost	1,264	1,330.7
Gross Unrealized Gains	495.9	618.5
Gross unrealized loss, less than 12 months	(22.8)	(11.1)
Gross unrealized loss, 12 months or greater	0	0
Available-for-sale Securities	1,737.1	1,938.1
Fixed Maturities [Member]
Investments [Line Items]
Cost or Amortized Cost	18,635.2	17,621.1
Gross Unrealized Gains	399.2	536.4
Gross unrealized loss, less than 12 months	(146.8)	(128.5)
Gross unrealized loss, 12 months or greater	(37.4)	(57.2)
Available-for-sale Securities	18,850.2	17,971.8
Non-Credit Component of Other-Than-Temporary Impairments Recognized in Accumulated Other Comprehensive Income	(5.8)	(6.8)
Fixed Maturities [Member] | United States Government Securities [Member]
Investments [Line Items]
Cost or Amortized Cost	323.9	315.7
Gross Unrealized Gains	2.8	4.6
Gross unrealized loss, less than 12 months	(0.8)	(0.3)
Gross unrealized loss, 12 months or greater	0	0
Available-for-sale Securities	325.9	320
Non-Credit Component of Other-Than-Temporary Impairments Recognized in Accumulated Other Comprehensive Income	0	0
Fixed Maturities [Member] | Government Sponsored Securities [Member]
Investments [Line Items]
Cost or Amortized Cost	87.7	94.6
Gross Unrealized Gains	0.8	0.8
Gross unrealized loss, less than 12 months	(0.1)	0
Gross unrealized loss, 12 months or greater	(0.2)	(0.4)
Available-for-sale Securities	88.2	95
Non-Credit Component of Other-Than-Temporary Impairments Recognized in Accumulated Other Comprehensive Income	0	0
Fixed Maturities [Member] | States, Municipalities And Political Subdivisions, Tax-Exempt [Member]
Investments [Line Items]
Cost or Amortized Cost	5,782.6	5,451.4
Gross Unrealized Gains	212.2	287
Gross unrealized loss, less than 12 months	(24.8)	(1.8)
Gross unrealized loss, 12 months or greater	(5.2)	(3)
Available-for-sale Securities	5,964.8	5,733.6
Non-Credit Component of Other-Than-Temporary Impairments Recognized in Accumulated Other Comprehensive Income	0	0
Fixed Maturities [Member] | Corporate Securities [Member]
Investments [Line Items]
Cost or Amortized Cost	9,380.6	8,335.9
Gross Unrealized Gains	119.8	162.9
Gross unrealized loss, less than 12 months	(112)	(123.1)
Gross unrealized loss, 12 months or greater	(23.2)	(43.2)
Available-for-sale Securities	9,365.2	8,332.5
Non-Credit Component of Other-Than-Temporary Impairments Recognized in Accumulated Other Comprehensive Income	(5.8)	(6.8)
Fixed Maturities [Member] | Options Embedded In Convertible Debt Securities [Member]
Investments [Line Items]
Cost or Amortized Cost	0.8	98.7
Gross Unrealized Gains	0	0
Gross unrealized loss, less than 12 months	0	0
Gross unrealized loss, 12 months or greater	0	0
Available-for-sale Securities	0.8	98.7
Non-Credit Component of Other-Than-Temporary Impairments Recognized in Accumulated Other Comprehensive Income	0	0
Fixed Maturities [Member] | Residential Mortgage-Backed Securities [Member]
Investments [Line Items]
Cost or Amortized Cost	1,895.2	2,099.7
Gross Unrealized Gains	52.4	68.9
Gross unrealized loss, less than 12 months	(7.1)	(1)
Gross unrealized loss, 12 months or greater	(7.5)	(8.6)
Available-for-sale Securities	1,933	2,159
Non-Credit Component of Other-Than-Temporary Impairments Recognized in Accumulated Other Comprehensive Income	0	0
Fixed Maturities [Member] | Commercial Mortgage-Backed Securities [Member]
Investments [Line Items]
Cost or Amortized Cost	432.3	504.8
Gross Unrealized Gains	4	6.1
Gross unrealized loss, less than 12 months	(1.1)	(0.6)
Gross unrealized loss, 12 months or greater	(0.2)	(0.4)
Available-for-sale Securities	435	509.9
Non-Credit Component of Other-Than-Temporary Impairments Recognized in Accumulated Other Comprehensive Income	0	0
Fixed Maturities [Member] | Other Debt Securities [Member]
Investments [Line Items]
Cost or Amortized Cost	732.1	720.3
Gross Unrealized Gains	7.2	6.1
Gross unrealized loss, less than 12 months	(0.9)	(1.7)
Gross unrealized loss, 12 months or greater	(1.1)	(1.6)
Available-for-sale Securities	737.3	723.1
Non-Credit Component of Other-Than-Temporary Impairments Recognized in Accumulated Other Comprehensive Income	$ 0	$ 0

Investments (Aggregate Fair Val

Investments (Aggregate Fair Value And Gross Unrealized Loss Of Fixed Maturity Securities And Equity Securities In An Unrealized Loss Position) (Details) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2015USD ($)securities	Dec. 31, 2014USD ($)securities
Schedule of Investments [Line Items]
Number of securities, less than 12 months | securities	3,418	2,564
Estimated fair value, less than 12 months	$ 7,547.2	$ 4,381.7
Gross unrealized loss, less than 12 months	$ (169.6)	$ (139.6)
Number of securities, 12 months or greater | securities	476	629
Estimated fair value, 12 months or greater	$ 769.7	$ 1,215.6
Gross unrealized loss, 12 months or greater	$ (37.4)	$ (57.2)
Equity Securities [Member]
Schedule of Investments [Line Items]
Number of securities, less than 12 months | securities	554	407
Estimated fair value, less than 12 months	$ 360.5	$ 125.4
Gross unrealized loss, less than 12 months	$ (22.8)	$ (11.1)
Number of securities, 12 months or greater | securities	0	0
Estimated fair value, 12 months or greater	$ 0	$ 0
Gross unrealized loss, 12 months or greater	$ 0	$ 0
Fixed Maturities [Member]
Schedule of Investments [Line Items]
Number of securities, less than 12 months | securities	2,864	2,157
Estimated fair value, less than 12 months	$ 7,186.7	$ 4,256.3
Gross unrealized loss, less than 12 months	$ (146.8)	$ (128.5)
Number of securities, 12 months or greater | securities	476	629
Estimated fair value, 12 months or greater	$ 769.7	$ 1,215.6
Gross unrealized loss, 12 months or greater	$ (37.4)	$ (57.2)
Fixed Maturities [Member] | United States Government Securities [Member]
Schedule of Investments [Line Items]
Number of securities, less than 12 months | securities	18	17
Estimated fair value, less than 12 months	$ 69.1	$ 145.3
Gross unrealized loss, less than 12 months	$ (0.8)	$ (0.3)
Number of securities, 12 months or greater | securities	2	2
Estimated fair value, 12 months or greater	$ 0.9	$ 0.9
Gross unrealized loss, 12 months or greater	$ 0	$ 0
Fixed Maturities [Member] | Government Sponsored Securities [Member]
Schedule of Investments [Line Items]
Number of securities, less than 12 months | securities	12	2
Estimated fair value, less than 12 months	$ 19	$ 0.3
Gross unrealized loss, less than 12 months	$ (0.1)	$ 0
Number of securities, 12 months or greater | securities	10	16
Estimated fair value, 12 months or greater	$ 20.7	$ 29.3
Gross unrealized loss, 12 months or greater	$ (0.2)	$ (0.4)
Fixed Maturities [Member] | States, Municipalities And Political Subdivisions, Tax-Exempt [Member]
Schedule of Investments [Line Items]
Number of securities, less than 12 months | securities	557	136
Estimated fair value, less than 12 months	$ 1,502.7	$ 315.6
Gross unrealized loss, less than 12 months	$ (24.8)	$ (1.8)
Number of securities, 12 months or greater | securities	39	80
Estimated fair value, 12 months or greater	$ 71.1	$ 174.3
Gross unrealized loss, 12 months or greater	$ (5.2)	$ (3)
Fixed Maturities [Member] | Corporate Securities [Member]
Schedule of Investments [Line Items]
Number of securities, less than 12 months | securities	1,895	1,802
Estimated fair value, less than 12 months	$ 4,702.7	$ 3,213.3
Gross unrealized loss, less than 12 months	$ (112)	$ (123.1)
Number of securities, 12 months or greater | securities	277	314
Estimated fair value, 12 months or greater	$ 397	$ 514.6
Gross unrealized loss, 12 months or greater	$ (23.2)	$ (43.2)
Fixed Maturities [Member] | Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Number of securities, less than 12 months | securities	277	78
Estimated fair value, less than 12 months	$ 573.7	$ 155
Gross unrealized loss, less than 12 months	$ (7.1)	$ (1)
Number of securities, 12 months or greater | securities	114	186
Estimated fair value, 12 months or greater	$ 195.2	$ 398.3
Gross unrealized loss, 12 months or greater	$ (7.5)	$ (8.6)
Fixed Maturities [Member] | Commercial Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Number of securities, less than 12 months | securities	49	43
Estimated fair value, less than 12 months	$ 135.8	$ 156.2
Gross unrealized loss, less than 12 months	$ (1.1)	$ (0.6)
Number of securities, 12 months or greater | securities	13	10
Estimated fair value, 12 months or greater	$ 28	$ 33.2
Gross unrealized loss, 12 months or greater	$ (0.2)	$ (0.4)
Fixed Maturities [Member] | Other Debt Securities [Member]
Schedule of Investments [Line Items]
Number of securities, less than 12 months | securities	56	79
Estimated fair value, less than 12 months	$ 183.7	$ 270.6
Gross unrealized loss, less than 12 months	$ (0.9)	$ (1.7)
Number of securities, 12 months or greater | securities	21	21
Estimated fair value, 12 months or greater	$ 56.8	$ 65
Gross unrealized loss, 12 months or greater	$ (1.1)	$ (1.6)

Investments (Amortized Cost And

Investments (Amortized Cost And Fair Value Of Fixed Maturity Securities, By Contractual Maturity) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Schedule of Investments [Line Items]
Available-for-sale securities, Amortized Cost	$ 19,899.2	$ 18,951.8
Available-for-sale securities, Estimated Fair Value	20,587.3	19,909.9
Fixed Maturities [Member]
Schedule of Investments [Line Items]
Due in one year or less, Amortized Cost	425.4
Due after one year through five years, Amortized Cost	4,691.9
Due after five years through ten years, Amortized Cost	5,427.2
Due after ten years, Amortized Cost	5,763.2
Mortgage-backed securities, Amortized Cost	2,327.5
Available-for-sale securities, Amortized Cost	18,635.2	17,621.1
Due in one year or less, Estimated Fair Value	428.2
Due after one year through five years, Estimated Fair Value	4,740.8
Due after five years through ten years, Estimated Fair Value	5,510.2
Due after ten years, Estimated Fair Value	5,803
Mortgage-backed securities, Estimated Fair Value	2,368
Available-for-sale securities, Estimated Fair Value	$ 18,850.2	$ 17,971.8

Investments (Proceeds and Reali

Investments (Proceeds and Realized Gains Losses From Investments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Investments [Abstract]
Proceeds	$ 3,234.8	$ 2,560	$ 6,160.7	$ 4,961.4
Gross realized gains	148.4	106.2	282.1	189.1
Gross realized losses	$ (56.1)	$ (40.4)	$ (143.3)	$ (81.6)

Investments (Securities Lending

Investments (Securities Lending Programs) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	$ 1,718.2	$ 1,515.3
United States Government Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	171.9
Corporate Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	747.2
Equity Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	418.7
Other Debt Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	380.4
Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	1,646.6
Overnight and Continuous [Member] | United States Government Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	100.3
Overnight and Continuous [Member] | Corporate Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	747.2
Overnight and Continuous [Member] | Equity Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	418.7
Overnight and Continuous [Member] | Other Debt Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	380.4
Less than 30 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	0
Less than 30 Days [Member] | United States Government Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	0
Less than 30 Days [Member] | Corporate Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	0
Less than 30 Days [Member] | Equity Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	0
Less than 30 Days [Member] | Other Debt Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	0
30 to 90 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	14.2
30 to 90 Days [Member] | United States Government Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	14.2
30 to 90 Days [Member] | Corporate Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	0
30 to 90 Days [Member] | Equity Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	0
30 to 90 Days [Member] | Other Debt Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	0
Greater than 90 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	57.4
Greater than 90 Days [Member] | United States Government Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	57.4
Greater than 90 Days [Member] | Corporate Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	0
Greater than 90 Days [Member] | Equity Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	0
Greater than 90 Days [Member] | Other Debt Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Collateral received for securities loaned, at carrying value	$ 0

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Schedule of Investments [Line Items]
Available-for-sale Securities	$ 20,587.3		$ 20,587.3		$ 19,909.9
Other-than-temporary impairment losses recognized in income	21.8	$ 10.9	35.8	$ 21.7
Collateral received for securities loaned, at carrying value	1,718.2		$ 1,718.2		$ 1,515.3
Securities lending transactions, ratio of fair value of collateral held to securities on loan			103.00%
Securities lending transactions, initial collateral percentage value			102.00%
Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities	2,368		$ 2,368
Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities	655.4		655.4
Sub-Prime Mortgage-Backed and Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities	34.1		34.1
Unrealized Gain (Loss) on Securities			1.2
Alt-A Mortgage-Backed and Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities	$ 69.4		69.4
Unrealized Gain (Loss) on Securities			$ 4.6

Fair Value (Fair Value Measurem

Fair Value (Fair Value Measurements By Level For Assets Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$ 686.4	$ 573.2
Available-for-sale Securities	20,587.3	19,909.9
Other invested assets, current	23.4	20.2
Securities lending collateral	1,718.3	1,515.2
Total assets	23,233.4	22,243.3
Total liabilities	(215.1)	(260.4)
Fixed Maturities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	18,850.2	17,971.8
Fixed Maturities [Member] | United States Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	325.9	320
Fixed Maturities [Member] | Government Sponsored Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	88.2	95
Fixed Maturities [Member] | States, Municipalities And Political Subdivisions, Tax-Exempt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	5,964.8	5,733.6
Fixed Maturities [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	9,365.2	8,332.5
Fixed Maturities [Member] | Options Embedded In Convertible Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.8	98.7
Fixed Maturities [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,933	2,159
Fixed Maturities [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	435	509.9
Fixed Maturities [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	737.3	723.1
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,737.1	1,938.1
Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets, current	23.4	20.2
Derivatives Excluding Embedded Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	218	224.8
Derivative liability	(215.1)	(260.4)
Level I [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	686.4	573.2
Securities lending collateral	943.1	808.3
Total assets	3,830.6	3,514.9
Total liabilities	0	0
Level I [Member] | Fixed Maturities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	619.5	416.3
Level I [Member] | Fixed Maturities [Member] | United States Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	325.9	320
Level I [Member] | Fixed Maturities [Member] | Government Sponsored Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level I [Member] | Fixed Maturities [Member] | States, Municipalities And Political Subdivisions, Tax-Exempt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level I [Member] | Fixed Maturities [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	212.1	7.1
Level I [Member] | Fixed Maturities [Member] | Options Embedded In Convertible Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level I [Member] | Fixed Maturities [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level I [Member] | Fixed Maturities [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level I [Member] | Fixed Maturities [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	81.5	89.2
Level I [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,558.2	1,696.9
Level I [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets, current	23.4	20.2
Level I [Member] | Derivatives Excluding Embedded Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	0	0
Level II [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Securities lending collateral	775.2	706.9
Total assets	19,147.2	18,525.6
Total liabilities	(215.1)	(260.4)
Level II [Member] | Fixed Maturities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	18,029.2	17,401
Level II [Member] | Fixed Maturities [Member] | United States Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level II [Member] | Fixed Maturities [Member] | Government Sponsored Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	88.2	95
Level II [Member] | Fixed Maturities [Member] | States, Municipalities And Political Subdivisions, Tax-Exempt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	5,964.8	5,733.6
Level II [Member] | Fixed Maturities [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	8,960.7	8,180.8
Level II [Member] | Fixed Maturities [Member] | Options Embedded In Convertible Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.8	98.7
Level II [Member] | Fixed Maturities [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,933	2,159
Level II [Member] | Fixed Maturities [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	432.2	506.6
Level II [Member] | Fixed Maturities [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	649.5	627.3
Level II [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	124.8	192.9
Level II [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets, current	0	0
Level II [Member] | Derivatives Excluding Embedded Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	218	224.8
Derivative liability	(215.1)	(260.4)
Level III [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Securities lending collateral	0	0
Total assets	255.6	202.8
Total liabilities	0	0
Level III [Member] | Fixed Maturities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	201.5	154.5
Level III [Member] | Fixed Maturities [Member] | United States Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level III [Member] | Fixed Maturities [Member] | Government Sponsored Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level III [Member] | Fixed Maturities [Member] | States, Municipalities And Political Subdivisions, Tax-Exempt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level III [Member] | Fixed Maturities [Member] | Corporate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	192.4	144.6
Level III [Member] | Fixed Maturities [Member] | Options Embedded In Convertible Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level III [Member] | Fixed Maturities [Member] | Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Level III [Member] | Fixed Maturities [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	2.8	3.3
Level III [Member] | Fixed Maturities [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	6.3	6.6
Level III [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	54.1	48.3
Level III [Member] | Short-term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets, current	0	0
Level III [Member] | Derivatives Excluding Embedded Options [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0
Derivative liability	$ 0	$ 0

Fair Value (Reconciliation Of T

Fair Value (Reconciliation Of The Beginning And Ending Balances Of Assets Measured At Fair Value On A Recurring Basis Using Level III Inputs) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 223.1	$ 196.7	$ 202.8	$ 177.9
Total gains (losses) recognized in net income	(1.2)	7.2	(2)	25.2
Total gains (losses) recognized in accumulated other comprehensive income	1	16.8	3.7	14.3
Purchases	65.2	19.9	105.1	38.2
Sales	(5.3)	(13)	(10.7)	(15.8)
Settlements	(11.7)	(1.6)	(25.5)	(7.3)
Transfers into Level III	4.2	24.2	4.9	24.2
Transfers out of Level III	(19.7)	(3.1)	(22.7)	(9.6)
Ending balance	255.6	247.1	255.6	247.1
Change in unrealized losses included in net income related to assets still held	(0.2)	(4)	(1.6)	(8.3)
Corporate Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	165.5	114	144.6	115.2
Total gains (losses) recognized in net income	(0.8)	(3)	(1)	(6.3)
Total gains (losses) recognized in accumulated other comprehensive income	1.4	9.6	3	12.7
Purchases	57.2	11.6	89.6	20.9
Sales	(4.1)	(4.5)	(4.1)	(6.2)
Settlements	(11.3)	(1.5)	(24.9)	(3.6)
Transfers into Level III	4.2	24.2	4.9	24.2
Transfers out of Level III	(19.7)	0	(19.7)	(6.5)
Ending balance	192.4	150.4	192.4	150.4
Change in unrealized losses included in net income related to assets still held	0	(3.6)	(0.6)	(7.6)
Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	3.2	3.1	3.3	6.5
Total gains (losses) recognized in net income	0	0	0	0
Total gains (losses) recognized in accumulated other comprehensive income	0	0	0	0
Purchases	0	3.6	0	3.6
Sales	0	0	0	0
Settlements	(0.4)	0	(0.5)	(3.4)
Transfers into Level III	0	0	0	0
Transfers out of Level III	0	(3.1)	0	(3.1)
Ending balance	2.8	3.6	2.8	3.6
Change in unrealized losses included in net income related to assets still held	0	0	0	0
Other Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	2.6	14.8	6.6	14.8
Total gains (losses) recognized in net income	0	0	0.2	0
Total gains (losses) recognized in accumulated other comprehensive income	0	0.1	(0.2)	0.3
Purchases	3.7	3	3.7	3
Sales	0	0	(0.9)	0
Settlements	0	(0.1)	(0.1)	(0.3)
Transfers into Level III	0	0	0	0
Transfers out of Level III	0	0	(3)	0
Ending balance	6.3	17.8	6.3	17.8
Change in unrealized losses included in net income related to assets still held	0	0	0	0
Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	51.8	43.2	48.3	41.4
Total gains (losses) recognized in net income	(0.4)	(0.4)	(1.2)	(0.7)
Total gains (losses) recognized in accumulated other comprehensive income	(0.4)	7.1	0.9	1.3
Purchases	4.3	1.7	11.8	10.7
Sales	(1.2)	(8.5)	(5.7)	(9.6)
Settlements	0	0	0	0
Transfers into Level III	0	0	0	0
Transfers out of Level III	0	0	0	0
Ending balance	54.1	43.1	54.1	43.1
Change in unrealized losses included in net income related to assets still held	(0.2)	(0.4)	(1)	(0.7)
Long Term Receivable [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0	21.6	0	0
Total gains (losses) recognized in net income	0	10.6	0	32.2
Total gains (losses) recognized in accumulated other comprehensive income	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	0	0	0	0
Transfers into Level III	0	0	0	0
Transfers out of Level III	0	0	0	0
Ending balance	0	32.2	0	32.2
Change in unrealized losses included in net income related to assets still held	$ 0	$ 0	$ 0	$ 0

Fair Value (Carrying And Estima

Fair Value (Carrying And Estimated Fair Values by Level Of Financial Instruments Not Recorded At Fair Value On Consolidated Balance Sheet) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets, long-term	$ 1,803.3	$ 1,695.9
Convertible debentures	469.6
Carrying Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets, long-term	1,803.3	1,695.9
Short-term borrowings	540	400
Commercial paper	697.4
Notes	14,926.3	13,687.5
Convertible debentures	469.6	956.4
Estimated Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets, long-term	1,803.3	1,695.9
Short-term borrowings	540	400
Commercial paper	697.4
Notes	15,148.6	14,794.8
Convertible debentures	1,608.4	2,581.9
Estimated Fair Value [Member] | Level III [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets, long-term	1,803.3	1,695.9
Short-term borrowings	0	0
Commercial paper	0
Notes	0	0
Convertible debentures	0	0
Estimated Fair Value [Member] | Level II [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets, long-term	0	0
Short-term borrowings	540	400
Commercial paper	697.4
Notes	15,148.6	14,794.8
Convertible debentures	1,608.4	2,581.9
Estimated Fair Value [Member] | Level I [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other invested assets, long-term	0	0
Short-term borrowings	0	0
Commercial paper	0
Notes	0	0
Convertible debentures	$ 0	$ 0

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Tax Disclosure [Abstract]
Income tax expense	$ 698.9	$ 532.6	$ 1,402.8	$ 971.3
Effective tax rate	44.90%	42.10%	44.90%	40.60%
Health Insurance Provider Fee, increase in nondeductible income tax expense	$ 114.2	$ 80.5	$ 227.5	$ 161

Retirement Benefits (Components

Retirement Benefits (Components Of Net Periodic Benefit (Credit) Cost) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3.3	$ 3.2	$ 6.6	$ 6.5
Interest cost	17.1	18.5	34.1	37
Expected return on assets	(35.9)	(34.3)	(71.6)	(68.7)
Recognized actuarial loss	6.5	5.2	12.9	10.5
Settlement loss	1.7	1.4	3	2.5
Amortization of prior service credit	(0.2)	(0.2)	(0.4)	(0.4)
Net periodic (credit) benefit cost	(7.5)	(6.2)	(15.4)	(12.6)
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.6	0.8	1.1	1.6
Interest cost	5.8	6.5	11.7	13.1
Expected return on assets	(5.9)	(5.9)	(11.8)	(11.7)
Recognized actuarial loss	3.8	2.4	7.6	4.7
Settlement loss	0	0	0	0
Amortization of prior service credit	(3.6)	(3.6)	(7.2)	(7.2)
Net periodic (credit) benefit cost	$ 0.7	$ 0.2	$ 1.4	$ 0.5

Debt (Carrying Value Of Long-te

Debt (Carrying Value Of Long-term Debt) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Long-term Debt	$ 16,093.3	$ 14,643.9
Current portion of long-term debt	(624.9)	(624.3)
Long-term debt, less current portion	$ 15,468.4	$ 14,019.6
Senior Unsecured Notes [Member] | One Point Two Five Zero Percent Due Two Thousand Fifteen [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.25%	1.25%
Long-term Debt	$ 624.9	$ 624.3
Senior Unsecured Notes [Member] | Two Point Three Seven Five Percent Due Two Thousand And Seventeen [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.375%	2.375%
Long-term Debt	$ 400	$ 398.9
Senior Unsecured Notes [Member] | Five Point Eight Seven Five Percent Due Two Thousand Seventeen [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.875%	5.875%
Long-term Debt	$ 527.2	$ 526.7
Senior Unsecured Notes [Member] | One Point Eight Seven Five Percent Due Two Thousand Eighteen [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.875%	1.875%
Long-term Debt	$ 621.6	$ 616.4
Senior Unsecured Notes [Member] | Two Point Three Zero Zero Percent Due Two Thousand Eighteen [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.30%	2.30%
Long-term Debt	$ 645.1	$ 644.3
Senior Unsecured Notes [Member] | Two Point Two Five Zero Percent Due Two Thousand Nineteen [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.25%	2.25%
Long-term Debt	$ 843	$ 842.1
Senior Unsecured Notes [Member] | Seven Point Zero Zero Zero Percent Due Two Thousand Nineteen [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.00%	7.00%
Long-term Debt	$ 438.7	$ 438.5
Senior Unsecured Notes [Member] | Four Point Three Five Zero Percent Due Two Thousand Twenty [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.35%	4.35%
Long-term Debt	$ 698.8	$ 695.3
Senior Unsecured Notes [Member] | Three Point Seven Zero Zero Percent Due Two Thousand Twenty One [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.70%	3.70%
Long-term Debt	$ 695.9	$ 695.6
Senior Unsecured Notes [Member] | Three Point One Two Five Percent Due Two Thousand Twenty Two [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.125%	3.125%
Long-term Debt	$ 842.2	$ 841.6
Senior Unsecured Notes [Member] | Three Point Three Zero Zero Percent Due Two Thousand Twenty Three [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.30%	3.30%
Long-term Debt	$ 991.8	$ 991.2
Senior Unsecured Notes [Member] | Three Point Five Zero Zero Percent Due Two Thousand Twenty Four [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.50%	3.50%
Long-term Debt	$ 790.4	$ 789.8
Senior Unsecured Notes [Member] | Five Point Nine Five Zero Percent Due Two Thousand Thirty Four [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.95%	5.95%
Long-term Debt	$ 444.4	$ 444.4
Senior Unsecured Notes [Member] | Five Point Eight Five Zero Percent Due Two Thousand Thirty Six [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.85%	5.85%
Long-term Debt	$ 767.8	$ 767.7
Senior Unsecured Notes [Member] | Six Point Three Seven Five Percent Due Two Thousand Thirty Seven [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.375%	6.375%
Long-term Debt	$ 639.5	$ 639.3
Senior Unsecured Notes [Member] | Five Point Eight Zero Zero Percent Due Two Thousand Forty [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.80%	5.80%
Long-term Debt	$ 193.7	$ 206.4
Senior Unsecured Notes [Member] | Four Point Six Two Five Percent Due Two Thousand Forty Two [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.625%	4.625%
Long-term Debt	$ 885.6	$ 885.4
Senior Unsecured Notes [Member] | Four Point Six Five Zero Percent Due Two Thousand Forty Three [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.65%	4.65%
Long-term Debt	$ 985.2	$ 985
Senior Unsecured Notes [Member] | Four Point Six Five Zero Percent Due Two Thousand Forty Four [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.65%	4.65%
Long-term Debt	$ 790.3	$ 790.1
Senior Unsecured Notes [Member] | Five Point One Zero Zero Percent Due Two Thousand Forty Four [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.10%	5.10%
Long-term Debt	$ 593.2	$ 593.1
Senior Unsecured Notes [Member] | Four Point Eight Five Zero Percent Due Two Thousand Fifty Four [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.85%	4.85%
Long-term Debt	$ 246.6	$ 246.5
Remarketable Subordinated Notes [Member] | One Point Nine Zero Zero Percent Due Two Thousand Twenty Eight [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.90%
Long-term Debt	$ 1,235.5	$ 0
Surplus Notes [Member] | Nine Point Zero Zero Zero Percent Due Two Thousand Twenty Seven [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	9.00%	9.00%
Long-term Debt	$ 24.9	$ 24.9
Senior Convertible Debentures [Member] | Two Point Seven Five Zero Percent Due Two Thousand Forty Two [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.75%	2.75%
Long-term Debt	$ 469.6	$ 956.4
Commercial Paper
Debt Instrument [Line Items]
Long-term Debt	$ 697.4	$ 0

Debt (Convertible Debenture Ter

Debt (Convertible Debenture Terms) (Details) - Jun. 30, 2015 $ / shares in Units, $ in Millions	USD ($)$ / shares
Debt Disclosure [Abstract]
Outstanding principal amount	$ 733
Unamortized debt discount	254.7
Net debt carrying amount	469.6
Equity component carrying amount	$ 265.7
Conversion rate (shares of common stock per $1,000 of principal)	13.4231
Effective conversion price (per $1,000 of principal amount) per share | $ / shares	$ 74.4977

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($) shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Jul. 23, 2015
Debt Instrument [Line Items]
(Gain) loss on extinguishment of debt	$ (2,900,000)	$ 3,000,000	$ 500,000	$ 6,000,000
Equity units, outstanding principal amount	$ 733,000,000		733,000,000
Line of credit facility, maximum borrowing capacity					$ 26,500,000,000
Repayments of Long-term Debt			(1,930,000,000)	$ (45,100,000)
Equity Unit Purchase Agreements [Member]
Debt Instrument [Line Items]
Equity Units Date of Issuance	May 12, 2015
Equity Units Issued	25
Equity units, outstanding principal amount	$ 1,250,000,000		1,250,000,000
Equity Units, stated value per unit (whole dollars)	$ 50		50
Equity Units, purchase contract settlement date	May 1, 2018
Net proceeds from issuance of Equity Units	$ 1,228,800,000
Forward Contract Indexed to Issuer's Equity, Settlement Alternatives	On May 1, 2018, if the applicable market value of our common stock is equal to or greater than $207.805 per share, the settlement rate will be 0.2406 shares of our common stock. If the applicable market value of our common stock is less than $207.805 per share but greater than $143.865 per share, the settlement rate will be a number of shares of our common stock equal to $50 (whole dollars) divided by the applicable market value of our common stock. If the applicable market value of common stock is less than or equal to $143.865, the settlement rate will be 0.3475 shares of our common stock. Holders of the Equity Units may elect early settlement at a minimum settlement rate of 0.2406 shares of our common stock for each purchase contract being settled.
Stock purchase contract liability, present value	$ 120,900,000		$ 120,900,000
Equity Units, contract adjustment payment rate	3.35%		3.35%
Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Senior unsecured notes, carrying value	$ 13,665,900,000		$ 13,665,900,000
Debt instruments, repurchased face amount	$ 13,000,000		13,000,000
Senior unsecured notes, repurchase price			16,200,000
(Gain) loss on extinguishment of debt			$ 3,400,000
Remarketable Subordinated Notes [Member]
Debt Instrument [Line Items]
Equity Units, ownership interest percentage in remarketable subordinated notes	5.00%		5.00%
Interest rate, remarketable subordinated notes	1.90%
Surplus Notes [Member]
Debt Instrument [Line Items]
Unsecured surplus note, carrying amount	$ 24,900,000		$ 24,900,000
Senior Convertible Debentures [Member]
Debt Instrument [Line Items]
Debt instruments, repurchased face amount	700,500,000		700,500,000
(Gain) loss on extinguishment of debt	(2,900,000)
Aggregate principal amount of convertible debentures surrendered for conversion	66,500,000		66,500,000
Repayments of Long-term Debt	1,646,300,000
Federal Home Loan Bank Advances [Member]
Debt Instrument [Line Items]
Federal Home Loan Bank, advances, short-term	$ 540,000,000		$ 540,000,000
Debt instrument interest rate	0.194%		0.194%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 2,000,000,000		$ 2,000,000,000
Line of credit maturity date	Sep. 29, 2016
Commercial Paper Program
Debt Instrument [Line Items]
Commercial paper authorized	$ 2,500,000,000		2,500,000,000
Commercial paper	$ 697,400,000		$ 697,400,000

Commitments And Contingencies (

Commitments And Contingencies (Details) - Jun. 30, 2015 $ in Millions	USD ($)class_actions
Commitments And Contingencies [Line Items]
Possible losses, in excess of established reserves, minimum	$ 0
Possible losses, in excess of established reserves, maximum	250
International Business Machines Corporation [Member]
Commitments And Contingencies [Line Items]
Long-term purchase commitment, amount	430
Affiliated Computer Services, Inc. [Member]
Commitments And Contingencies [Line Items]
Long-term purchase commitment, amount	$ 47.1
In re WellPoint, Inc. Out-of-Network UCR Rates Litigation [Member]
Commitments And Contingencies [Line Items]
Number of putative class actions consolidated into a single lawsuit | class_actions	11

Capital Stock (Summary of Cash

Capital Stock (Summary of Cash Dividend Activity) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014
Capital [Abstract]
Declaration date	Apr. 28, 2015	Jan. 27, 2015	Apr. 29, 2014	Jan. 28, 2014
Record date	Jun. 10, 2015	Mar. 10, 2015	Jun. 10, 2014	Mar. 10, 2014
Payment date	Jun. 25, 2015	Mar. 25, 2015	Jun. 25, 2014	Mar. 25, 2014
Cash dividends per share	$ 0.6250	$ 0.6250	$ 0.4375	$ 0.4375
Total payment	$ 163.9	$ 166.6	$ 120.5	$ 123.4	$ 330.5	$ 243.9

Capital Stock (Summary of Share

Capital Stock (Summary of Share Repurchases) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Equity, Class of Treasury Stock [Line Items]
Shares repurchased	9.7	22.6
Average price per share	$ 145.63	$ 92.10
Aggregate cost	$ 1,410.6	$ 2,077.2
Authorization remaining at the end of each period	$ 4,281	$ 1,613.4

Capital Stock (Summary of Stock

Capital Stock (Summary of Stock Option Activity) (Details) - Jun. 30, 2015 - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Total
Number of Shares [Roll Forward]
Outstanding at beginning of period, Number of Shares	7.3
Granted, Number of Shares	1.2
Exercised, Number of Shares	(2.1)
Forfeited or expired, Number of Shares	(0.1)
Outstanding at end of period, Number of Shares	6.3
Exercisable at end of period, Number of Shares	3.4
Weighted-Average Option Price Per Share [Roll Forward]
Outstanding at beginning of period, Weighted-Average Option Price per Share	$ 70.30
Granted, Weighted-Average Option Price per Share	147.18
Exercised, Weighted-Average Option Price per Share	67.82
Forfeited or expired, Weighted-Average Option Price per Share	95.22
Outstanding at end of period, Weighted-Average Option Price per Share	85.83
Exercisable at end of period, Weighted-Average Option Price per Share	$ 66.52
Outstanding at end of period, Weighted-Average Remaining Contractual Life	4 years 8 months 23 days
Exercisable at end of period, Weighted-Average Remaining Contractual Life	2 years 8 months 23 days
Outstanding at end of period, Aggregate Intrinsic Value	$ 490.9
Exercisable at end of period, Aggregate Intrinsic Value	$ 335.9

Capital Stock (Nonvested Restri

Capital Stock (Nonvested Restricted Stock Activity Including Restricted Stock Units) (Details) - $ / shares shares in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Restricted Stock Shares and Units [Roll Forward]
Nonvested at Beginning Balance, Restricted Stock Shares and Units	3.6		3.6
Granted, Restricted Stock Shares and Units	0.9	0.1	0.9	1.4
Vested, Restricted Stock Shares And Units			(1.7)
Forfeited, Restricted Stock Shares And Units			(0.1)
Nonvested at Ending Balance, Restricted Stock Shares and Units			2.7
Weighted-Average Grant Date Fair Value Per Share [Roll Forward]
Nonvested at Beginning Balance, Weighted-Average Grant Date Fair Value per Share	$ 75.63		$ 75.63
Granted, Weighted-Average Grant Date Fair Value per Share			147.10	$ 90.17
Vested, Weighted-Average Grant Date Fair Value per Share			72.31
Forfeited, Weighted-Average Grant Date Fair Value per Share			96.51
Nonvested at Ending Balance, Weighted-Average Grant Date Fair Value per Share			$ 100.45

Capital Stock (Fair Values of O

Capital Stock (Fair Values of Options Granted During The Period Estimated Using Weighted-Average Assumptions) (Details)	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Capital [Abstract]
Risk-free interest rate	1.96%	2.16%
Volatility factor	31.00%	35.00%
Quarterly dividend yield	0.425%	0.50%
Weighted-average expected life (years)	4 years	3 years 9 months

Capital Stock (Schedule Of Weig

Capital Stock (Schedule Of Weighted-Average Fair Values Determined For The Periods) (Details) - $ / shares	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Capital [Abstract]
Options granted during the period	$ 34.01	$ 22.37
Restricted stock and stock awards granted during the period	$ 147.10	$ 90.17

Capital Stock (Narrative) (Deta

Capital Stock (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Jun. 30, 2014	Oct. 02, 2014	Feb. 04, 2014
Option Indexed to Issuer's Equity [Line Items]
Repurchase and retirement of common stock, shares		9.7	22.6
Equity units, outstanding principal amount	$ 733	$ 733
Increase in stock repurchase program authorization				$ 5,000
Call Option [Member]
Option Indexed to Issuer's Equity [Line Items]
Repurchase and retirement of common stock, shares		2.1
Average strike price	$ 135.03	$ 135.03
Put Option [Member]
Option Indexed to Issuer's Equity [Line Items]
Options indexed to issuer's equity, shares		5.3
Options expired unexercised		2.5
Remaining unexpired options		2.8
Shares subject to mandatory repurchase upon exipriation of the option contract if the market price of our common stock is less than the option strike price	2.8	2.8
Accelerated Share Repurchase Agreement [Member]
Option Indexed to Issuer's Equity [Line Items]
Repurchase and retirement of common stock, shares			6.6
Accelerated share repurchase agreement, amount					$ 600
Equity Unit Purchase Agreements [Member]
Option Indexed to Issuer's Equity [Line Items]
Equity Units Issued	25
Equity units, outstanding principal amount	$ 1,250	$ 1,250

Accumulated Other Comprehensi57

Accumulated Other Comprehensive Income (Reconciliation Of The Components Of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Investments, gross unrealized gains	$ 895.1	$ 1,284.8
Investments, gross unrealized losses	(207)	(65)
Investments, net pretax unrealized gains	688.1	1,219.8
Deferred tax liability	(241.3)	(425.9)
Net unrealized gains on investments	446.8	793.9
Non-credit component of other than temporary impairments on investments, unrealized losses	(5.7)	(0.8)
Non-credit component of other than temporary impairments on investments, deferred tax asset	2	0.3
Net unrealized non-credit component of other than temporary impairments on investments	(3.7)	(0.5)
Cash flow hedges, gross unrealized losses	(52.4)	(47.4)
Cash flow hedges, deferred tax asset	18.3	16.6
Net unrealized losses on cash flow hedges	(34.1)	(30.8)
Defined benefit pension plans, deferred net actuarial loss	(547.8)	(425.2)
Defined benefit pension plans, deferred prior service credits	1.8	13.7
Defined benefit pension plans, deferred tax asset	217.1	164.8
Net unrecognized periodic benefit costs for defined benefit pension plans	(328.9)	(246.7)
Postretirement benefit plans, deferred net actuarial loss	(203.6)	(152.4)
Postretirement benefit plans, deferred prior service credits	80.8	82.6
Defined benefit pension plans, deferred tax asset	48.7	27.9
Net unrecognized periodic benefit costs for postretirement benefit plans	(74.1)	(41.9)
Foreign currency translation adjustments, gross unrealized (losses) gains	(8.6)	1.6
Foreign currency translation adjustments, deferred tax asset (liability)	3	(0.6)
Net unrealized (losses) gains on foreign currency translation adjustments	(5.6)	1
Accumulated other comprehensive income	$ 0.4	$ 475	$ 171.9

Accumulated Other Comprehensi58

Accumulated Other Comprehensive Income (Other Comprehensive Income (Loss) Reclassification Adjustments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net holding (loss) gain on investment securities arising during the period, net of tax	$ (195.4)	$ 180.3	$ (113.9)	$ 340.7
Reclassification adjustment for net realized gain on investment securities, net of tax	(45.8)	(35.7)	(66.9)	(55.8)
Total reclassification adjustment on investments	(241.2)	144.6	(180.8)	284.9
Non-credit component of other-than-temporary impairments on investments, net of tax	(2.8)	(0.5)	0.7	0
Cash flow hedges, holding gain, net of tax	0.9	0.8	1.8	1.5
Net change in unrecognized periodic benefit costs for defined benefit pension and postretirement benefit plans, net of tax	4.9	3	9.6	5.9
Foreign currency translation adjustment, net of tax	0.7	(0.3)	(2.8)	(0.5)
Net (loss) gain recognized in other comprehensive income, net of tax	$ (237.5)	$ 147.6	$ (171.5)	$ 291.8

Accumulated Other Comprehensi59

Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income Reclassification Adjustments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) Reclassification Adjustments (Parantheticals) [Abstract]
Net holding gain (loss) on investment securities arising during the period, tax expense (benefit)	$ (109.3)	$ 99.4	$ (53.1)	$ 188.5
Reclassification adjustment for net realized gain (loss) on investment securities, tax expense (benefit)	24.7	19.2	36.1	30
Non-credit component of other than temporary impairments on investments, tax expense (benefit)	(1.5)	(0.3)	0.4	0
Cash flow hedges, holding gain (loss), tax expense (benefit)	0.5	0.4	1	0.8
Net change in unrecognized periodic benefit costs for defined benefit pension and postretirement benefit plans, tax expense	3.3	2.3	6.3	4.2
Foreign currency translation adjustment, tax expense (benefit)	0.4	(0.1)	(1.5)	(0.1)
Net gain recognized in other comprehensive income (loss), tax expense (benefit)	$ (131.3)	$ 82.5	$ (83)	$ 163.4

Earnings Per Share (Denominator

Earnings Per Share (Denominator For Basic And Diluted Earnings Per Share) (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Denominator for basic earnings per share - weighted-average shares	263.1	276.8	264.8	280.8
Effect of dilutive securities – employee stock options, non-vested restricted stock awards and convertible debentures	11.2	9.2	12.5	8.5
Denominator for diluted earnings per share	274.3	286	277.3	289.3

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) - shares shares in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Weighted average shares excluded from denominator for diluted earnings per share because the stock options were anti-dilutive	1.2		1.4	0.8	1
Restricted stock units issued under stock incentive plan		0.9	0.1	0.9	1.4
Restricted stock units excluded from the denominator for diluted earnings per share		0.4			0.7

Segment Information (Financial

Segment Information (Financial Data By Reportable Segment) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Operating revenue	$ 19,758.3	$ 18,230	$ 38,609.7	$ 35,874.8
Operating gain (loss)	1,512.1	1,222.9	3,091.4	2,341.6
Commercial and Specialty Business [Member]
Segment Reporting Information [Line Items]
Operating revenue	9,368.2	9,965	18,735.1	19,662.5
Operating gain (loss)	912	919.6	2,179	1,805.7
Government Business [Member]
Segment Reporting Information [Line Items]
Operating revenue	10,385	8,259.3	19,865.1	16,200.6
Operating gain (loss)	609.7	313.5	934.1	553.1
Other [Member]
Segment Reporting Information [Line Items]
Operating revenue	5.1	5.7	9.5	11.7
Operating gain (loss)	$ (9.6)	$ (10.2)	$ (21.7)	$ (17.2)

Segment Information (Reconcilia

Segment Information (Reconciliation Of Reportable Segments Operating Revenues To Total Revenues Reported In The Consolidated Statements Of Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting [Abstract]
Reportable segments operating revenues	$ 19,758.3	$ 18,230	$ 38,609.7	$ 35,874.8
Net investment income	186.7	188.5	354.3	372.2
Net realized gains on investments	92.3	65.8	138.8	107.5
Other-than-temporary impairment losses recognized in income	(21.8)	(10.9)	(35.8)	(21.7)
Total revenues	$ 20,015.5	$ 18,473.4	$ 39,067	$ 36,332.8

Segment Information (Reconcil64

Segment Information (Reconciliation Of Reportable Segments Operating Gain To Income Before Income Tax Expense Included In The Consolidated Statements Of Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting [Abstract]
Reportable segments operating gain	$ 1,512.1	$ 1,222.9	$ 3,091.4	$ 2,341.6
Net investment income	186.7	188.5	354.3	372.2
Net realized gains on investments	92.3	65.8	138.8	107.5
Other-than-temporary impairment losses recognized in income	(21.8)	(10.9)	(35.8)	(21.7)
Interest expense	(154.1)	(145.6)	(308.5)	(291.8)
Amortization of other intangible assets	(60.1)	(54)	(112.6)	(108)
(Gain) loss on extinguishment of debt	2.9	(3)	(0.5)	(6)
Income from continuing operations before income tax expense	$ 1,558	$ 1,263.7	$ 3,127.1	$ 2,393.8