UnitedHealth (UNH) 10-Q 7 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document	9 Months Ended
	Sep. 30, 2013	Oct. 31, 2013
Document Information [Line Items]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Entitiy Registrant Name	'UNITEDHEALTH GROUP INC	'
Entitiy Central Index Key	'0000731766	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	1,006,758,191

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$8,286	$8,406
Short-term investments	2,433	3,031
Accounts receivable, net	2,853	2,709
Other current receivables, net	3,772	2,889
Assets under management	2,694	2,773
Deferred income taxes	366	463
Prepaid expenses and other current assets	790	781
Total current assets	21,194	21,052
Long-term investments	18,783	17,711
Property, equipment and capitalized software, net	3,829	3,939
Goodwill	31,751	31,286
Other intangible assets, net	4,019	4,682
Other assets	2,287	2,215
Total assets	81,863	80,885
Current liabilities:	'	'
Medical costs payable	11,818	11,004
Accounts payable and accrued liabilities	7,145	6,984
Other policy liabilities	5,484	4,910
Commercial paper and current maturities of long-term debt	1,895	2,713
Unearned revenues	1,525	1,505
Total current liabilities	27,867	27,116
Long-term debt, less current maturities	14,888	14,041
Future policy benefits	2,459	2,444
Deferred income taxes	1,881	2,450
Other liabilities	1,622	1,535
Total liabilities	48,717	47,586
Commitments and contingencies (Note 9)	'	'
Redeemable noncontrolling interest	1,130	2,121
Shareholders' equity:	'	'
Preferred stock, $0.001 par value - 10 shares authorized; no shares issued or outstanding	0	0
Common stock, $0.01 par value - 3,000 shares authorized; 998 and 1,019 issued and outstanding	10	10
Additional paid-in capital	0	66
Retained earnings	32,593	30,664
Accumulated other comprehensive (loss) income	-587	438
Total shareholders' equity	32,016	31,178
Total liabilities and shareholders’ equity	$81,863	$80,885

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheet (Parenthetical) Condendsed Consolidated Balance Sheet (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, except Per Share data, unless otherwise specified
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	3,000	3,000
Common stock, shares issued	998	1,019
Common stock, shares outstanding	998	1,019
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	10	10
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues:	'	'	'	'
Premiums	$27,356	$24,640	$81,850	$73,880
Services	2,280	1,824	6,636	5,415
Products	825	693	2,325	2,059
Investment and other income	163	145	561	495
Total revenues	30,624	27,302	91,372	81,849
Operating costs:	'	'	'	'
Medical costs	22,044	19,471	66,786	59,423
Operating costs	4,869	4,277	14,308	12,453
Cost of products sold	731	627	2,082	1,881
Depreciation and amortization	349	317	1,025	939
Total operating costs	27,993	24,692	84,201	74,696
Earnings from operations	2,631	2,610	7,171	7,153
Interest expense	-178	-158	-532	-459
Earnings before income taxes	2,453	2,452	6,639	6,694
Provision for income taxes	-883	-895	-2,393	-2,412
Net earnings	1,570	1,557	4,246	4,282
Earnings attributable to noncontrolling interest	0	0	-48	0
Net earnings attributable to UnitedHealth Group common shareholders	$1,570	$1,557	$4,198	$4,282
Basic net earnings per common share attributable to UnitedHealth Group common shareholders	$1.56	$1.52	$4.16	$4.16
Diluted net earnings per common share attributable to UnitedHealth Group common shareholders	$1.53	$1.50	$4.09	$4.08
Basic weighted-average number of common shares outstanding	1,004	1,022	1,009	1,030
Dilutive effect of common stock equivalents	20	17	17	19
Diluted weighted-average number of common shares outstanding	1,024	1,039	1,026	1,049
Anti-dilutive shares excluded from the calculation of dilutive effect of common stock equivalents	7	23	11	19
Cash dividends declared per common share	$0.28	$0.21	$0.77	$0.59

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net earnings	$1,570	$1,557	$4,246	$4,282
Other comprehensive (loss) income:	'	'	'	'
Gross unrealized holding gains (losses) on investment securities during the period	26	166	-475	277
Income tax effect	-9	-54	172	-100
Total unrealized gains (losses), net of tax	17	112	-303	177
Gross reclassification adjustment for net realized gains included in net earnings	-31	-20	-137	-109
Income tax effect	11	7	50	40
Total reclassification adjustment, net of tax	-20	-13	-87	-69
Total foreign currency translation (losses) gains	-49	7	-635	6
Other comprehensive (loss) income	-52	106	-1,025	114
Comprehensive income	1,518	1,663	3,221	4,396
Comprehensive income attributable to noncontrolling interests	0	0	-48	0
Comprehensive income attributable to UnitedHealth Group common shareholders	$1,518	$1,663	$3,173	$4,396

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Changes in Shareholders' Equity (USD $)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Net Unrealized Investment Gain (Loss) [Member]	Foreign Currency Loss	Stockholders' Equity, Total [Member]
In Millions, unless otherwise specified					Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2011	'	$10	$0	$27,821	$476	($15)	$28,292
Balance (in shares) at Dec. 31, 2011	'	1,039	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net earnings attributable to UnitedHealth Group common shareholders	4,282	'	'	4,282	'	'	4,282
Other Comprehensive (Loss) Income	'	'	'	'	108	'	'
Foreign currency translation losses	6	'	'	'	'	6	'
Other Comprehensive Income (Loss), Net of Tax	114	'	'	'	'	'	114
Issuances of common stock, and related tax benefits (in shares)	'	21	'	'	'	'	'
Issuances of common stock, and related tax benefits	'	0	273	'	'	'	273
Share-based compensation, and related tax benefits	'	'	459	'	'	'	459
Common stock repurchases (in shares)	'	-48	'	'	'	'	'
Common stock repurchases	'	0	-732	-1,862	'	'	-2,594
Cash dividends paid on common stock	'	'	'	-603	'	'	-603
Balance at Sep. 30, 2012	'	10	0	29,638	584	-9	30,223
Balance (in shares) at Sep. 30, 2012	'	1,012	'	'	'	'	'
Balance at Dec. 31, 2012	31,178	10	66	30,664	516	-78	31,178
Balance (in shares) at Dec. 31, 2012	1,019	1,019	'	'	'	'	'
Increase (Decrease) in Stockholders' Equity [Roll Forward]	'	'	'	'	'	'	'
Net earnings attributable to UnitedHealth Group common shareholders	4,198	'	'	4,198	'	'	4,198
Other Comprehensive (Loss) Income	'	'	'	'	-390	'	'
Foreign currency translation losses	-635	'	'	'	'	-635	'
Other Comprehensive Income (Loss), Net of Tax	-1,025	'	'	'	'	'	-1,025
Issuances of common stock, and related tax benefits (in shares)	'	16	'	'	'	'	'
Issuances of common stock, and related tax benefits	'	0	397	'	'	'	397
Share-based compensation, and related tax benefits	'	'	312	'	'	'	312
Acquisition of noncontrolling interest adn related tax effects	'	'	81	'	'	'	81
Common stock repurchases (in shares)	-37	-37	'	'	'	'	'
Common stock repurchases	'	0	-856	-1,492	'	'	-2,348
Cash dividends paid on common stock	'	'	'	-777	'	'	-777
Balance at Sep. 30, 2013	$32,016	$10	$0	$32,593	$126	($713)	$32,016
Balance (in shares) at Sep. 30, 2013	998	998	'	'	'	'	'

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Operating activities	'	'
Net earnings	$4,246	$4,282
Noncash items:	'	'
Depreciation and amortization	1,025	939
Deferred income taxes	93	181
Share-based compensation	255	329
Other, net	-118	-154
Net change in other operating items, net of effects from acquisitions and changes in AARP balances:	'	'
Accounts receivable	-120	93
Other assets	-590	-101
Medical costs payable	788	141
Accounts payable and other liabilities	392	252
Other policy liabilities	-68	-316
Unearned revenues	20	-173
Cash flows from operating activities	5,923	5,473
Investing activities	'	'
Purchases of investments	-8,798	-7,432
Sales of investments	3,779	2,566
Maturities of investments	3,871	3,742
Cash paid for acquisitions, net of cash assumed	-330	-2,550
Cash received from dispositions	45	0
Purchases of property, equipment and capitalized software	-986	-786
Proceeds from disposal of property, equipment and capitalized software	146	0
Cash flows used for investing activities	-2,273	-4,460
Financing activities	'	'
Acquisition of noncontrolling interest	-1,474	0
Common stock repurchases	-2,348	-2,594
Proceeds from issuance of long-term debt	2,235	1,480
Repayments of long-term debt	-1,560	-631
(Repayments of) proceeds from commercial paper, net	-529	540
Cash dividends paid	-777	-603
Customer funds administered	308	309
Proceeds from common stock issuances	538	508
Other, net	-76	-535
Cash flows used for financing activities	-3,683	-1,526
Effect of exchange rate changes on cash and cash equivalents	-87	0
Decrease in cash and cash equivalents	-120	-513
Cash and cash equivalents, beginning of period	8,406	9,429
Cash and Cash Equivalents, end of period	$8,286	$8,916

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Basis of Presentation [Text Block]	'
	Basis of Presentation
	UnitedHealth Group Incorporated (both individually and together with its consolidated subsidiaries referred to as “UnitedHealth Group” and the “Company”) is a diversified health and well-being company whose mission is to help people live healthier lives and to make the health system work better for everyone. The Company offers a broad spectrum of products and services through two distinct platforms: UnitedHealthcare, which provides health care coverage and benefits services; and Optum, which provides information and technology-enabled health services.
	The Company has prepared the Condensed Consolidated Financial Statements according to U.S. Generally Accepted Accounting Principles (GAAP) and has included the accounts of UnitedHealth Group and its subsidiaries. The Company has eliminated intercompany balances and transactions. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. In accordance with the rules and regulations of the U.S. Securities and Exchange Commission (SEC), the Company has omitted certain footnote disclosures that would substantially duplicate the disclosures contained in its annual audited Consolidated Financial Statements. Therefore, these Condensed Consolidated Financial Statements should be read together with the Consolidated Financial Statements and the Notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2012 as filed with the SEC (2012 10-K). The accompanying Condensed Consolidated Financial Statements include all normal recurring adjustments necessary to present the interim financial statements fairly.
	Use of Estimates
	These Condensed Consolidated Financial Statements include certain amounts based on the Company’s best estimates and judgments. The Company’s most significant estimates relate to medical costs payable, and risk-adjusted and risk-sharing provisions related to revenues, valuation and impairment analysis of goodwill and other intangible assets, estimates of other policy liabilities and other current receivables, valuations of certain investments, and estimates and judgments related to income taxes and contingent liabilities. Certain of these estimates require the application of complex assumptions and judgments, often because they involve matters that are inherently uncertain and will likely change in subsequent periods. The impact of any changes in estimates is included in earnings in the period in which the estimate is adjusted.
	Recently Adopted Accounting Standards
	In February 2013, the Financial Accounting Standards Board (FASB) issued Accounting Standards Updated (ASU) No. 2013-02, “Comprehensive Income (Topic 220): Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income” (ASU 2013-02). ASU 2013-02 requires companies to report the effect of significant reclassifications out of accumulated other comprehensive income, by component, either on the face of the financial statements or in the notes to the financial statements and is intended to help entities improve the transparency of changes in other comprehensive income. ASU 2013-02 does not amend any existing requirements for reporting net income or other comprehensive income in the financial statements. ASU 2013-02 became effective for the Company's fiscal year 2013 and the new disclosures have been included with the Company’s investment disclosures in Note 2.
	The Company has determined that there have been no other recently adopted or issued accounting standards that had, or will have, a material impact on its Condensed Consolidated Financial Statements.

Investments

Investments	9 Months Ended
	Sep. 30, 2013
Investments [Abstract]	'
Investments [Text Block]	'
	Investments
	A summary of short-term and long-term investments by major security type is as follows:
	(in millions)	Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Gains			Losses
	September 30, 2013
	Debt securities - available-for-sale:
	U.S. government and agency obligations	$	2,466		$	11		$	(12	)	$	2,465
	State and municipal obligations	6,626			181			(57		)	6,750
	Corporate obligations	7,543			144			(53		)	7,634
	U.S. agency mortgage-backed securities	2,028			30			(38		)	2,020
	Non-U.S. agency mortgage-backed securities	660			15			(8		)	667
	Total debt securities - available-for-sale	19,323			381			(168		)	19,536
	Equity securities - available-for-sale	817			4			(13		)	808
	Debt securities - held-to-maturity:
	U.S. government and agency obligations	179			3			—			182
	State and municipal obligations	28			—			—			28
	Corporate obligations	665			—			—			665
	Total debt securities - held-to-maturity	872			3			—			875
	Total investments	$	21,012		$	388		$	(181	)	$	21,219
	December 31, 2012
	Debt securities - available-for-sale:
	U.S. government and agency obligations	$	2,501		$	38		$	(1	)	$	2,538
	State and municipal obligations	6,282			388			(3		)	6,667
	Corporate obligations	6,930			283			(4		)	7,209
	U.S. agency mortgage-backed securities	2,168			70			—			2,238
	Non-U.S. agency mortgage-backed securities	538			36			—			574
	Total debt securities - available-for-sale	18,419			815			(8		)	19,226
	Equity securities - available-for-sale	668			10			(1		)	677
	Debt securities - held-to-maturity:
	U.S. government and agency obligations	168			6			—			174
	State and municipal obligations	30			—			—			30
	Corporate obligations	641			2			—			643
	Total debt securities - held-to-maturity	839			8			—			847
	Total investments	$	19,926		$	833		$	(9	)	$	20,750
	The fair values of the Company’s mortgage-backed securities by credit rating (when multiple credit ratings are available for an individual security, the average of the available ratings is used) and origination date as of September 30, 2013 were as follows:
	(in millions)	AAA			AA			Non-Investment			Total Fair
								Grade			Value
	2013	$	74		$	—		$	—		$	74
	2012	109			—			—			109
	2011	20			—			—			20
	2010	9			—			—			9
	2009	13			—			—			13
	2007	78			—			2			80
	Pre - 2007	349			3			10			362
	U.S. agency mortgage-backed securities	2,020			—			—			2,020
	Total	$	2,672		$	3		$	12		$	2,687
	The Company includes any securities backed by Alt-A or sub-prime mortgages and any commercial mortgage loans in default in the non-investment grade column in the table above.
	The amortized cost and fair value of available-for-sale debt securities as of September 30, 2013, by contractual maturity, were as follows:
	(in millions)	Amortized			Fair
		Cost			Value
	Due in one year or less	$	2,540		$	2,553
	Due after one year through five years	7,219			7,351
	Due after five years through ten years	4,945			5,008
	Due after ten years	1,931			1,937
	U.S. agency mortgage-backed securities	2,028			2,020
	Non-U.S. agency mortgage-backed securities	660			667
	Total debt securities - available-for-sale	$	19,323		$	19,536
	The amortized cost and fair value of held-to-maturity debt securities as of September 30, 2013, by contractual maturity, were as follows:
	(in millions)	Amortized			Fair
		Cost			Value
	Due in one year or less	$	445		$	445
	Due after one year through five years	155			155
Due after five years through ten years	136			138
Due after ten years	136			137
Total debt securities - held-to-maturity	$	872		$	875
The fair value of available-for-sale investments with gross unrealized losses by major security type and length of time that individual securities have been in a continuous unrealized loss position were as follows:
	Less Than 12 Months
	and in Total
(in millions)	Fair			Gross
	Value			Unrealized
				Losses
September 30, 2013
Debt securities - available-for-sale:
U.S. government and agency obligations	$	676		$	(12	)
State and municipal obligations	2,114			(57		)
Corporate obligations	2,730			(53		)
U.S. agency mortgage-backed securities	927			(38		)
Non-U.S. agency mortgage-backed securities	332			(8		)
Total debt securities - available-for-sale	$	6,779		$	(168	)
Equity securities - available-for-sale	$	137		$	(13	)
December 31, 2012
Debt securities - available-for-sale:
U.S. government and agency obligations	$	183		$	(1	)
State and municipal obligations	362			(3		)
Corporate obligations	695			(4		)
Total debt securities - available-for-sale	$	1,240		$	(8	)
Equity securities - available-for-sale	$	13		$	(1	)
The unrealized losses from all securities as of September 30, 2013 were generated from approximately 5,800 positions out of a total of 19,500 positions. The Company believes that it will collect the principal and interest due on its investments that have an amortized cost in excess of fair value. The unrealized losses were primarily caused by interest rate increases and not by unfavorable changes in the credit ratings associated with these securities. At each reporting period, the Company evaluates securities for impairment when the fair value of the investment is less than its amortized cost. The Company evaluated the underlying credit quality and credit ratings of the issuers, noting neither a significant deterioration since purchase nor other factors leading to an other-than-temporary impairment (OTTI). Therefore, the Company believes these losses to be temporary. As of September 30, 2013, the Company did not have the intent to sell any of the securities in an unrealized loss position.
A portion of the Company’s investments in equity securities and venture capital funds consists of investments held in various public and nonpublic companies concentrated in the areas of health care services and related information technologies. Market conditions that affect the value of health care and related technology stocks will likewise impact the value of the Company’s equity portfolio. The equity securities and venture capital funds were evaluated for severity and duration of unrealized loss, overall market volatility and other market factors.
Net realized gains reclassified out of accumulated other comprehensive income were from the following sources:
	Three Months Ended September 30,						Nine Months Ended September 30,
(in millions)	2013			2012			2013			2012
Total OTTI	$	(3	)	$	—		$	(7	)	$	(4	)
Portion of loss recognized in other comprehensive income	—			—			—			—
Net OTTI recognized in earnings	(3		)	—			(7		)	(4		)
Gross realized losses from sales	—			(2		)	(3		)	(5		)
Gross realized gains from sales	34			22			147			118
Net realized gains (included in Investment and Other Income on the Condensed Consolidated Statements of Operations)	31			20			137			109
Income tax effect (included in Provision for Income Taxes on the Condensed Consolidated Statements of Operations)	(11		)	(7		)	(50		)	(40		)
Realized gains, net of taxes	$	20		$	13		$	87		$	69

Fair_Value

Fair Value	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value [Text Block]	'
	Fair Value
	Certain assets and liabilities are measured at fair value in the Condensed Consolidated Financial Statements or have fair values disclosed in the Notes to the Condensed Consolidated Financial Statements. These assets and liabilities are classified into one of three levels of a hierarchy defined by GAAP. In instances in which the inputs used to measure fair value fall into different levels of the fair value hierarchy, the fair value measurement is categorized in its entirety based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular item to the fair value measurement in its entirety requires judgment, including the consideration of inputs specific to the asset or liability.
	The fair value hierarchy is summarized as follows:
	Level 1 — Quoted prices (unadjusted) for identical assets/liabilities in active markets.
	Level 2 — Other observable inputs, either directly or indirectly, including:
	•	Quoted prices for similar assets/liabilities in active markets;
	•	Quoted prices for identical or similar assets/liabilities in non-active markets (e.g., few transactions, limited information, non-current prices, high variability over time);
	•	Inputs other than quoted prices that are observable for the asset/liability (e.g., interest rates, yield curves, implied volatilities, credit spreads); and
	•	Inputs that are corroborated by other observable market data.
	Level 3 — Unobservable inputs that cannot be corroborated by observable market data.
	Transfers between levels, if any, are recorded as of the beginning of the reporting period in which the transfer occurs; there were no transfers between Levels 1, 2 or 3 of any financial assets or liabilities during 2013 or 2012.
	Non-financial assets and liabilities or financial assets and liabilities that are measured at fair value on a nonrecurring basis are subject to fair value adjustments only in certain circumstances, such as when the Company records an impairment. There were no significant fair value adjustments for these assets and liabilities recorded during the three and nine months ended September 30, 2013 or 2012.
	The following methods and assumptions were used to estimate the fair value and determine the fair value hierarchy classification of each class of financial instrument included in the tables below:
	Cash and Cash Equivalents. The carrying value of cash and cash equivalents approximates fair value as maturities are less than three months. Fair values of cash equivalent instruments that do not trade on a regular basis in active markets are classified as Level 2.
	Debt and Equity Securities. Fair values of debt and equity securities are based on quoted market prices, where available. The Company obtains one price for each security primarily from a third-party pricing service (pricing service), which generally uses quoted or other observable inputs for the determination of fair value. The pricing service normally derives the security prices through recently reported trades for identical or similar securities, and, if necessary, makes adjustments through the reporting date based upon available observable market information. For securities not actively traded, the pricing service 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. Inputs that are often used in the valuation methodologies include, but are not limited to, benchmark yields, credit spreads, default rates, prepayment speeds and non-binding broker quotes. As the Company is responsible for the determination of fair value, it performs quarterly analyses on the prices received from the pricing service to determine whether the prices are reasonable estimates of fair value. Specifically, the Company compares the prices received from the pricing service to prices reported by a secondary pricing source, such as its custodian, its investment consultant and third-party investment advisors. Additionally, the Company compares changes in the reported market values and returns to relevant market indices to test the reasonableness of the reported prices. The Company’s internal price verification procedures and reviews of fair value methodology documentation provided by independent pricing services have not historically resulted in adjustment in the prices obtained from the pricing service.
	Fair values of debt securities that do not trade on a regular basis in active markets but are priced using other observable inputs are classified as Level 2.
	Fair value estimates for Level 1 and Level 2 equity securities are based on quoted market prices for actively traded equity securities and/or other market data for the same or comparable instruments and transactions in establishing the prices.
	The Company’s Level 3 equity securities are primarily investments in venture capital securities. The fair values of Level 3 investments in venture capital portfolios are estimated using a market valuation technique that relies heavily on management assumptions and qualitative observations. Under the market approach, the fair values of the Company’s various venture capital investments are computed using limited quantitative and qualitative observations of activity for similar companies in the current market. The Company’s market modeling utilizes, as applicable, transactions for comparable companies in similar industries and having similar revenue and growth characteristics; and similar preferences in their capital structure. Key significant unobservable inputs in the market technique include implied earnings before interest, taxes, depreciation and amortization (EBITDA) multiples and revenue multiples. Additionally, the fair values of certain of the Company’s venture capital securities are based off of recent transactions in inactive markets for identical or similar securities. Significant changes in any of these inputs could result in significantly lower or higher fair value measurements.
	Throughout the procedures discussed above in relation to the Company’s processes for validating third-party pricing information, the Company validates the understanding of assumptions and inputs used in security pricing and determines the proper classification in the hierarchy based on that understanding.
	AARP Program-related Investments. The Company provides health insurance products and services to members of AARP under a Supplemental Health Insurance Program (AARP Program). AARP Program-related investments consist of debt and equity securities held to fund costs associated with the AARP Program and are priced and classified using the same methodologies as the Company’s debt and equity securities.
	Interest Rate and Currency Swaps. Fair values of the Company’s swaps are estimated using the terms of the swaps and publicly available information including market yield curves. Because the swaps are unique and not actively traded but are valued using other observable inputs, the fair values are classified as Level 2.
	Long-term Debt. The fair value of the Company’s long-term debt is estimated and classified using the same methodologies as the Company’s investments in debt securities.
	AARP Program-related Other Liabilities. AARP Program-related other liabilities consist of liabilities that represent the amount of net investment gains and losses related to AARP Program-related investments that accrue to the benefit of the AARP policyholders.
	The following table presents a summary of fair value measurements by level and carrying values for items measured at fair value on a recurring basis in the Condensed Consolidated Balance Sheets excluding AARP Program-related assets and liabilities, which are presented in a separate table below:
	(in millions)		Quoted Prices			Other			Unobservable			Total
			in Active			Observable			Inputs			Fair and Carrying
			Markets			Inputs			(Level 3)			Value
			(Level 1)			(Level 2)
	September 30, 2013
	Cash and cash equivalents		$	7,943		$	343		$	—		$	8,286
	Debt securities - available-for-sale:
	U.S. government and agency obligations		1,899			566			—			2,465
	State and municipal obligations		—			6,750			—			6,750
	Corporate obligations		31			7,576			27			7,634
	U.S. agency mortgage-backed securities		—			2,020			—			2,020
	Non-U.S. agency mortgage-backed securities		—			661			6			667
	Total debt securities - available-for-sale		1,930			17,573			33			19,536
	Equity securities - available-for-sale		536			26			246			808
	Currency swap assets		—			22			—			22
	Total assets at fair value		$	10,409		$	17,964		$	279		$	28,652
	Percentage of total assets at fair value		36		%	63		%	1		%	100		%
	Interest rate swap liabilities		$	—		$	79		$	—		$	79
	December 31, 2012
	Cash and cash equivalents		$	7,615		$	791		$	—		$	8,406
	Debt securities - available-for-sale:
	U.S. government and agency obligations		1,752			786			—			2,538
	State and municipal obligations		—			6,667			—			6,667
	Corporate obligations		13			7,185			11			7,209
	U.S. agency mortgage-backed securities		—			2,238			—			2,238
	Non-U.S. agency mortgage-backed securities		—			568			6			574
	Total debt securities - available-for-sale		1,765			17,444			17			19,226
	Equity securities - available-for-sale		450			3			224			677
	Interest rate swap assets		—			14			—			14
	Total assets at fair value		$	9,830		$	18,252		$	241		$	28,323
	Percentage of total assets at fair value		35		%	64		%	1		%	100		%
	Interest rate and currency swap liabilities		$	—		$	14		$	—		$	14
	The following table presents a summary of fair value measurements by level and carrying values for certain financial instruments not measured at fair value on a recurring basis in the Condensed Consolidated Balance Sheets:
	(in millions)		Quoted Prices			Other			Unobservable			Total			Total Carrying Value
			in Active			Observable			Inputs			Fair
			Markets			Inputs			(Level 3)			Value
			(Level 1)			(Level 2)
	September 30, 2013
	Debt securities - held-to-maturity:
U.S. government and agency obligations		$	182		$	—		$	—		$	182		$	179
State and municipal obligations		—			—			28			28			28
Corporate obligations		47			341			277			665			665
Total debt securities - held-to-maturity		$	229		$	341		$	305		$	875		$	872
Long-term debt		$	—		$	16,604		$	—		$	16,604		$	15,723
December 31, 2012
Debt securities - held-to-maturity:
U.S. government and agency obligations		$	174		$	—		$	—		$	174		$	168
State and municipal obligations		—			1			29			30			30
Corporate obligations		10			346			287			643			641
Total debt securities - held-to-maturity		$	184		$	347		$	316		$	847		$	839
Long-term debt		$	—		$	17,034		$	—		$	17,034		$	15,167
The carrying amounts reported in the Condensed Consolidated Balance Sheets for other current financial assets and liabilities approximate fair value because of their short-term nature. These assets and liabilities are not listed in the table above.
A reconciliation of the beginning and ending balances of assets measured at fair value on a recurring basis using Level 3 inputs is as follows:
		Three Months Ended									Nine Months Ended
(in millions)		Debt			Equity			Total			Debt			Equity			Total
		Securities			Securities						Securities			Securities
September 30, 2013
Balance at beginning of period		$	38		$	245		$	283		$	17		$	224		$	241
Purchases		3			9			12			25			51			76
Sales		(7		)	—			(7		)	(7		)	(21		)	(28		)
Net unrealized losses in accumulated other comprehensive income		—			(7		)	(7		)	(1		)	(13		)	(14		)
Net realized (losses) gains in investment and other income		(1		)	(1		)	(2		)	(1		)	5			4
Balance at end of period		$	33		$	246		$	279		$	33		$	246		$	279
September 30, 2012
Balance at beginning of period		$	7		$	228		$	235		$	208		$	209		$	417
Purchases		—			2			2			—			53			53
Sales		—			(11		)	(11		)	—			(20		)	(20		)
Settlements		(1		)	—			(1		)	(1		)	—			(1		)
Net unrealized losses in accumulated other comprehensive income		—			(9		)	(9		)	—			(12		)	(12		)
Net realized gains in investment and other income		—			8			8			—			9			9
Transfers to held-to-maturity		—			—			—			(201		)	(21		)	(222		)
Balance at end of period		$	6		$	218		$	224		$	6		$	218		$	224
The following table presents quantitative information regarding unobservable inputs that were significant to the valuation of assets measured at fair value on a recurring basis using Level 3 inputs:
								Range
(in millions)		Fair Value			Valuation Technique		Unobservable Input	Low		High
September 30, 2013
Equity securities - available-for-sale
Venture capital portfolios		$	210		Market approach - comparable companies		Revenue multiple	1		10
							EBITDA multiple	7		10
		36			Market approach - recent transactions		Inactive market transactions	N/A		N/A
Total equity securities		$	246
available-for-sale
Also included in the Company’s assets measured at fair value on a recurring basis using Level 3 inputs were $33 million of available-for-sale debt securities at September 30, 2013, which were not significant.
The Company elected to measure the entirety of the AARP Assets Under Management at fair value pursuant to the fair value option. See Note 2 of Notes to the Consolidated Financial Statements in the Company’s 2012 10-K for further detail on AARP. The following table presents fair value information about the AARP Program-related financial assets and liabilities:
(in millions)		Quoted Prices			Other			Total
		in Active			Observable			Fair and Carrying
		Markets			Inputs			Value
		(Level 1)			(Level 2)
September 30, 2013
Cash and cash equivalents		$	227		$	—		$	227
Debt securities:
U.S. government and agency obligations		487			271			758
State and municipal obligations		—			61			61
Corporate obligations		—			1,077			1,077
U.S. agency mortgage-backed securities		—			428			428
Non-U.S. agency mortgage-backed securities		—			139			139
Total debt securities		487			1,976			2,463
Equity securities - available-for-sale		—			4			4
Total assets at fair value		$	714		$	1,980		$	2,694
Other liabilities		$	8		$	18		$	26
December 31, 2012
Cash and cash equivalents		$	230		$	—		$	230
Debt securities:
U.S. government and agency obligations		545			244			789
State and municipal obligations		—			51			51
Corporate obligations		—			1,118			1,118
U.S. agency mortgage-backed securities		—			427			427
Non-U.S. agency mortgage-backed securities		—			155			155
Total debt securities		545			1,995			2,540
Equity securities - available-for-sale		—			3			3
Total assets at fair value		$	775		$	1,998		$	2,773
Other liabilities		$	23		$	58		$	81

Medicare_Part_D_Pharmacy_Benef

Medicare Part D Pharmacy Benefits Medicare Part D Pharmacy Benefits	9 Months Ended
	Sep. 30, 2013
Medicare Part D Pharmacy Benefit Contracts [Abstract]	'
Medicare Part D Pharmacy Benefits Contract [Text Block]	'
	Medicare Part D Pharmacy Benefits
	The Condensed Consolidated Balance Sheets include the following amounts associated with the Medicare Part D program:
		September 30, 2013						December 31, 2012
	(in millions)	Subsidies		Drug Discount		Risk-Share		Subsidies		Drug Discount		Risk-Share
	Other current receivables	$	638	$	523	$	—	$	461	$	314	$	—
	Other policy liabilities	—		380		469		—		319		438
	The Catastrophic Reinsurance and Low-Income Member Cost Sharing Subsidies (Subsidies) and drug discounts represent cost reimbursements under the Medicare Part D program. The Company is fully reimbursed by the Centers for Medicare and Medicaid Services (CMS) for costs incurred for these contract elements and, accordingly, there is no insurance risk to the Company. Amounts received for these contract elements are not reflected as premium revenues, but rather are accounted for as a reduction of receivables and/or increase in deposit liabilities. CMS provides prospective payments for the drug discounts, which the Company records as liabilities when received. The drug discounts are ultimately funded by the pharmaceutical manufacturers. The Company bills them for claims under the program and records those bills as receivables. Related cash flows are presented as customer funds administered within financing activities in the Condensed Consolidated Statements of Cash Flows.
	Premiums from CMS are subject to risk-sharing provisions based on a comparison of the Company’s annual bid estimates of prescription drug costs and the actual costs incurred. Variances may result in CMS making additional payments to the Company or require the Company to remit funds to CMS subsequent to the end of the year. The Company records risk-share adjustments to premium revenue and to other current receivables or other policy liabilities in the Condensed Consolidated Balance Sheets.

Medical_Cost_Development

Medical Cost Development	9 Months Ended
	Sep. 30, 2013
Medical Cost Development [Abstract]	'
Medical Cost Development Disclosure Text Block	'
	Medical Cost Development
	The following table provides details of the Company's net favorable medical cost development:
		Three Months Ended September 30,				Nine Months Ended September 30,
	(in millions)	2013		2012		2013		2012
	Related to Prior Years	$	180	$	170	$	580	$	790
	Related to Current Year	110		220		N/A		N/A
	The favorable development for the three and nine months ended September 30, 2013 and September 30, 2012 was primarily driven by lower than expected health system utilization levels.

Commercial_Paper_and_LongTerm_

Commercial Paper and Long-Term Debt	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Commercial Paper and Long-Term Debt [Text Block]	'
	Commercial Paper and Long-Term Debt
	Commercial paper and long-term debt consisted of the following:
			September 30, 2013									December 31, 2012
	(in millions, except percentages)		Par			Carrying			Fair			Par			Carrying		Fair
			Value			Value			Value			Value			Value		Value
	Commercial Paper		$	1,060		$	1,060		$	1,060		$	1,587		$	1,587	$	1,587
	4.875% senior unsecured notes due February 2013		—			—			—			534			534		536
	4.875% senior unsecured notes due April 2013		—			—			—			409			411		413
	4.750% senior unsecured notes due February 2014		172			175			175			172			178		180
	5.000% senior unsecured notes due August 2014		389			401			405			389			411		414
	Senior unsecured floating-rate notes due August 2014		250			250			250			—			—		—
	4.875% senior unsecured notes due March 2015 (a)		416			435			440			416			444		453
	0.850% senior unsecured notes due October 2015 (a)		625			624			627			625			623		627
	5.375% senior unsecured notes due March 2016 (a)		601			645			663			601			660		682
	1.875% senior unsecured notes due November 2016		400			398			409			400			397		412
	5.360% senior unsecured notes due November 2016		95			95			108			95			95		110
	6.000% senior unsecured notes due June 2017		441			481			509			441			489		528
	1.400% senior unsecured notes due October 2017 (a)		625			614			617			625			622		626
	6.000% senior unsecured notes due November 2017		156			168			178			156			170		191
	6.000% senior unsecured notes due February 2018		1,100			1,117			1,282			1,100			1,120		1,339
	1.625% senior unsecured notes due March 2019		500			498			482			—			—		—
	3.875% senior unsecured notes due October 2020		450			443			474			450			442		499
	4.700% senior unsecured notes due February 2021		400			416			437			400			417		466
	3.375% senior unsecured notes due November 2021 (a)		500			481			499			500			512		533
	2.875% senior unsecured notes due March 2022		1,100			1,005			1,045			1,100			998		1,128
	0.000% senior unsecured notes due November 2022		15			9			10			15			9		11
	2.750% senior unsecured notes due February 2023 (a)		625			576			582			625			619		631
	2.875% senior unsecured notes due March 2023		750			747			706			—			—		—
	5.800% senior unsecured notes due March 2036		850			845			940			850			845		1,025
	6.500% senior unsecured notes due June 2037		500			495			604			500			495		659
	6.625% senior unsecured notes due November 2037		650			645			795			650			645		860
	6.875% senior unsecured notes due February 2038		1,100			1,084			1,381			1,100			1,084		1,510
	5.700% senior unsecured notes due October 2040		300			298			332			300			298		364
	5.950% senior unsecured notes due February 2041		350			348			401			350			348		440
	4.625% senior unsecured notes due November 2041		600			593			572			600			593		641
	4.375% senior unsecured notes due March 2042		502			486			462			502			486		521
	3.950% senior unsecured notes due October 2042		625			611			536			625			611		622
	4.250% senior unsecured notes due March 2043		750			740			683			—			—		—
	Total U.S. dollar denominated debt		16,897			16,783			17,664			16,117			16,143		18,008
	Cetip Interbank Deposit Rate (CDI) + 1.3% Subsidiary floating debt due October 2013		—			—			—			147			148		150
	CDI + 1.45% Subsidiary floating debt due October 2014		—			—			—			147			149		150
	110% CDI Subsidiary floating debt due December 2014		—			—			—			147			151		147
	CDI + 1.6% Subsidiary floating debt due October 2015		—			—			—			74			76		76
	Brazilian Extended National Consumer Price Index (IPCA) + 7.61% Subsidiary floating debt due October 2015		—			—			—			73			87		90
	Total Brazilian real denominated debt (in U.S. dollars)		—			—			—			588			611		613
	Total commercial paper and long-term debt		$	16,897		$	16,783		$	17,664		$	16,705		$	16,754	$	18,621
	(a)	Fixed-rate debt instruments hedged with interest rate swap contracts. See below for more information on the Company’s interest rate swaps.
	Commercial Paper and Bank Credit Facilities
	Commercial paper consists of short-duration, senior unsecured debt privately placed on a discount basis through broker-dealers. As of September 30, 2013, the Company’s outstanding commercial paper had a weighted-average annual interest rate of 0.2%.
	The Company has $3.0 billion five-year and $1.0 billion 364-day revolving bank credit facilities with 21 banks, which mature in November 2017 and November 2013, respectively. These facilities provide liquidity support for the Company’s $4.0 billion commercial paper program and are available for general corporate purposes. There were no amounts outstanding under these facilities as of September 30, 2013. The interest rates on borrowings are variable based on term and are calculated based on the London Interbank Offered Rate (LIBOR) plus a credit spread based on the Company’s senior unsecured credit ratings. As of September 30, 2013, the annual interest rates on both bank credit facilities, had they been drawn, would have ranged from 1.0% to 1.2%.
	Debt Covenants
	The Company’s bank credit facilities contain various covenants including requiring the Company to maintain a debt to debt-plus-equity ratio of not more than 50%. The Company was in compliance with its debt covenants as of September 30, 2013.
	Interest Rate Swap Contracts
	The Company uses interest rate swap contracts to convert a portion of its interest rate exposure from fixed rates to floating rates to more closely align interest expense with interest income received on its cash equivalent and variable rate investment balances. The floating rates are benchmarked to LIBOR. The swaps are designated as fair value hedges on the Company’s fixed-rate debt. Since the critical terms of the swaps match those of the debt being hedged, they are assumed to be highly effective hedges and all changes in fair value of the swaps are recorded as an adjustment to the carrying value of the related debt with no net impact recorded in the Condensed Consolidated Statements of Operations.
	The following table summarizes the location and fair value of the interest rate swap fair value hedges on the Company’s Condensed Consolidated Balance Sheet:
	Type of Fair Value Hedge		Notional Amount			Fair Value			Balance Sheet Location
			(in billions)			(in millions)
	September 30, 2013
	Interest rate swap contracts		$	3.4		$	79		Other liabilities
	31-Dec-12
	Interest rate swap contracts		$	2.8		$	14		Other assets
						11			Other liabilities
	The following table provides a summary of the effect of changes in fair value of fair value hedges on the Company’s Condensed Consolidated Statements of Operations:
		Three Months Ended September 30,						Nine Months Ended September 30,
(in millions)		2013			2012			2013			2012
Hedge (interest rate swap) gain (loss) recognized in interest expense		$	9		$	5		$	(82	)	$	17
Hedged item (long-term debt) (loss) gain recognized in interest expense		(9		)	(5		)	82			(17		)
Net impact on the Company’s Condensed Consolidated Statements of Operations		$	—		$	—		$	—		$	—

Shareholders_Equity_Shareholde

Shareholders' Equity Shareholder's Equity	9 Months Ended
	Sep. 30, 2013
Shareholders' Equity [Abstract]	'
Stockholders' Equity Note Disclosure [Text Block]	'
	Shareholders' Equity
	Share Repurchase Program
	Under its Board of Directors’ authorization, the Company maintains a share repurchase program. The objectives of the share repurchase program are to optimize the Company’s capital structure and cost of capital, thereby improving returns to shareholders, as well as to offset the dilutive impact of share-based awards. Repurchases may be made from time to time in open market purchases or other types of transactions (including prepaid or structured share repurchase programs), subject to certain Board restrictions. In June 2013, the Board renewed and expanded the Company’s share repurchase program with an authorization to repurchase up to 110 million shares of its common stock. During the nine months ended September 30, 2013, the Company repurchased 37 million shares at an average price of $63.87 per share and an aggregate cost of $2.3 billion. As of September 30, 2013, the Company had Board authorization to purchase up to an additional 95 million shares of its common stock.
	Dividends
	In June 2013, the Company’s Board of Directors increased the Company’s cash dividend to shareholders to an annual dividend rate of $1.12 per share, paid quarterly. Since June 2012, the Company had paid an annual dividend of $0.85 per share, paid quarterly. Declaration and payment of future quarterly dividends is at the discretion of the Board and may be adjusted as business needs or market conditions change.
	The following table provides details of the Company’s 2013 dividend payments:
	Payment Date	Amount per Share		Total Amount Paid
				(in millions)
	26-Mar-13	$	0.2125	$	216
	26-Jun-13	0.28		281
	24-Sep-13	0.28		280

ShareBased_Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	'
	Share-Based Compensation
	The Company’s outstanding share-based awards consist mainly of non-qualified stock options, stock-settled stock appreciation rights (SARs) and restricted stock and restricted stock units (collectively, restricted shares). As of September 30, 2013, the Company had 35 million shares available for future grants of share-based awards under its share-based compensation plan, including, but not limited to, incentive or non-qualified stock options, SARs and 15 million of awards in restricted shares.
	Stock Options and SARs
	Stock option and SAR activity for the nine months ended September 30, 2013 is summarized in the table below:
		Shares			Weighted-				Weighted-		Aggregate
					Average				Average		Intrinsic Value
					Exercise				Remaining
					Price				Contractual Life
		(in millions)							(in years)		(in millions)
	Outstanding at beginning of period	63			$	45
	Granted	8			58
	Exercised	(25	)		43
	Forfeited	(2	)		55
	Outstanding at end of period	44			48				4.6		$	1,054
	Exercisable at end of period	33			46				3.2		840
	Vested and expected to vest, end of period	43			48				4.6		1,043
	Restricted Shares
	Restricted share activity for the nine months ended September 30, 2013 is summarized in the table below:
	(shares in millions)		Shares			Weighted-Average
						Grant Date
						Fair Value
						per Share
	Nonvested at beginning of period		9			$	46
	Granted		3			58
	Forfeited		(1	)		50
	Nonvested at end of period		11			50
	Other Share-Based Compensation Data
	(in millions, except per share amounts)		Three Months Ended September 30,							Nine Months Ended September 30,
			2013				2012			2013			2012
	Stock Options and SARs
	Weighted-average grant date fair value of shares granted, per share		$	23			$	16		$	19		$	18
	Total intrinsic value of stock options and SARs exercised		182				44			507			442
	Restricted Shares
	Weighted-average grant date fair value of shares granted, per share		72				51			58			52
	Total fair value of restricted shares vested		—				5			—			357
	Share-Based Compensation Items
	Share-based compensation expense, before tax		79				87			255			329
	Share-based compensation expense, net of tax effects		67				70			174			230
	Income tax benefit realized from share-based award exercises		62				14			178			288
	(in millions, except years)		September 30, 2013
	Unrecognized compensation expense related to share awards		$	374
	Weighted-average years to recognize compensation expense		1.3
	Share-Based Compensation Recognition and Estimates
	The principal assumptions the Company used in calculating grant-date fair value for stock options and SARs were as follows:
			Three Months Ended September 30,				Nine Months Ended September 30,
			2013		2012		2013		2012
	Risk-free interest rate		1.60%		0.70%		1.0% - 1.6%		0.7% - 0.9%
	Expected volatility		41.80%		44.00%		41.8% - 43.0%		43.4% - 44.0%
	Expected dividend yield		1.50%		1.70%		1.4% - 1.5%		1.2% - 1.7%
	Forfeiture rate		5.00%		5.00%		5.00%		5.00%
	Expected life in years		5.3		5.3		5.3		5.3 - 5.6
	Risk-free interest rates are based on U.S. Treasury yields in effect at the time of grant. Expected volatilities are based on the historical volatility of the Company’s common stock and the implied volatility from exchange-traded options on the Company’s common stock. Expected dividend yields are based on the per share cash dividend paid by the Company. The Company uses historical data to estimate option and SAR exercises and forfeitures within the valuation model. The expected lives of options and SARs granted represents the period of time that the awards granted are expected to be outstanding based on historical exercise patterns.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies Disclosure [Text Block]	'
	Commitments and Contingencies
	Legal Matters
	Because of the nature of its businesses, the Company is frequently made party to a variety of legal actions and regulatory inquiries, including class actions and suits brought by members, care providers, consumer advocacy organizations, customers and regulators, relating to the Company’s businesses, including management and administration of health benefit plans and other services. These matters include medical malpractice, employment, intellectual property, antitrust, privacy and contract claims, and claims related to health care benefits coverage and other business practices.
	The Company records liabilities for its estimates of probable costs resulting from these matters where appropriate. Estimates of costs resulting from legal and regulatory matters involving the Company are inherently difficult to predict, particularly where the matters: involve indeterminate claims for monetary damages or may involve fines, penalties or punitive damages; present novel legal theories or represent a shift in regulatory policy; involve a large number of claimants or regulatory bodies; are in the early stages of the proceedings; or could result in a change in business practices. Accordingly, the Company is often unable to estimate the losses or ranges of losses for those matters where there is a reasonable possibility or it is probable that a loss may be incurred.
	Litigation Matters
	California Claims Processing Matter. On January 25, 2008, the California Department of Insurance (CDI) issued an Order to Show Cause to PacifiCare Life and Health Insurance Company, a subsidiary of the Company, alleging violations of certain insurance statutes and regulations related to an alleged failure to include certain language in standard claims correspondence, timeliness and accuracy of claims processing, interest payments, care provider contract implementation, care provider dispute resolution and other related matters. Although the Company believes that CDI has never issued a penalty in excess of $8 million, CDI has advocated a penalty of approximately $325 million in this matter. The matter has been the subject of an administrative hearing before a California administrative law judge since December 2009, and in August 2013, the administrative law judge issued a non-binding proposed decision recommending a penalty in an amount that is not material to
	the Company’s results of operations, cash flows or financial condition. The California Insurance Commissioner may accept, reject or modify the administrative law judge’s ruling, issue his own decision, and impose a fine or penalty. The Commissioner’s decision is subject to challenge in court. The Company cannot reasonably estimate the range of loss, if any, that may result from this matter given the procedural status of the dispute, the legal issues presented (including the legal basis for the majority of the alleged violations), the inherent difficulty in predicting regulatory fines and penalties, and the various remedies and levels of judicial review available to the Company in the event a fine or penalty is assessed.
	Endoscopy Center of Southern Nevada Litigation. In April 2013, a Las Vegas jury awarded $24 million in compensatory damages and $500 million in punitive damages against a Company health plan and its parent corporation on the theory that they were negligent in their credentialing and monitoring of an in-network endoscopy center owned and operated by independent physicians who were subsequently linked by regulators to an outbreak of hepatitis C. In September 2013, the trial court reduced the overall award to $366 million following post-trial motions. Company plans are party to 41 additional individual lawsuits and two class actions relating to the outbreak. The Company cannot reasonably estimate the range of loss, if any, that may result from these matters given the likelihood of reversal on appeal, the availability of statutory and other limits on damages, the novel legal theories being advanced by the plaintiffs, the various postures of the remaining cases, the availability in many cases of federal defenses under Medicare law and the Employee Retirement Income Security Act, and the pendency of certain relevant legal questions before the Nevada Supreme Court. The Company is vigorously defending these lawsuits.
	Government Investigations, Audits and Reviews
	The Company has been, or is currently involved in various governmental investigations, audits and reviews. These include routine, regular and special investigations, audits and reviews by CMS, state insurance and health and welfare departments, state attorneys general, the Office of the Inspector General, the Office of Personnel Management, the Office of Civil Rights, the Government Accountability Office, the Federal Trade Commission, U.S. Congressional committees, the U.S. Department of Justice, U.S. Attorneys, the SEC, the Brazilian securities regulator - Comissão de Valores Mobiliários, Internal Revenue Service, the Brazilian federal revenue service - the Secretaria da Receita Federal, the U.S. Department of Labor, the Federal Deposit Insurance Corporation and other governmental authorities. Certain of the Company’s businesses have been reviewed or are currently under review, including for, among other things, compliance with coding and other requirements under the Medicare risk-adjustment model.
	In February 2012, CMS announced a final Risk Adjustment Data Validation (RADV) audit and payment adjustment methodology and that it will conduct RADV audits beginning with the 2011 payment year. These audits involve a review of medical records maintained by care providers and may result in retrospective adjustments to payments made to health plans. CMS has not communicated how the final payment adjustment under its methodology will be implemented.
	The Company cannot reasonably estimate the range of loss, if any, that may result from any material government investigations, audits and reviews in which it is currently involved given the inherent difficulty in predicting regulatory action, fines and penalties, if any, and the various remedies and levels of judicial review available to the Company in the event of an adverse finding.

Segment_Financial_Information

Segment Financial Information	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment Financial Information [Text Block]	'
	Segment Financial Information
	Factors used to determine the Company’s reportable segments include the nature of operating activities, economic characteristics, existence of separate senior management teams and the type of information presented to the Company’s chief operating decision maker to evaluate its results of operations. Reportable segments with similar economic characteristics are combined. The Company’s four reportable segments are UnitedHealthcare, OptumHealth, OptumInsight and OptumRx.
	During 2013, the Company acquired all of Amil’s remaining public shares for $1.5 billion, bringing the Company’s ownership of Amil to 90%. For more information on the Company's investment in Amil, see Note 6 of the Notes of the Consolidated Financial Statements in the Company's 2012 10-K.
	Transactions between reportable segments principally consist of sales of pharmacy benefit products and services to UnitedHealthcare customers by OptumRx, certain product offerings and care management and integrated care delivery services sold to UnitedHealthcare by OptumHealth, and health information and technology solutions, consulting and other services sold to UnitedHealthcare by OptumInsight. These transactions are recorded at management’s estimate of fair value. Intersegment transactions are eliminated in consolidation. For more information on the Company’s segments see Note 13 of the Notes of the Consolidated Financial Statements in the Company's 2012 10-K.
	Corporate and intersegment elimination amounts are presented to reconcile the reportable segment results to the consolidated results. The following table presents the reportable segment financial information:
				Optum
	(in millions)	UnitedHealthcare		OptumHealth		OptumInsight		OptumRx		Total Optum		Corporate and			Consolidated
												Intersegment
												Eliminations
	Three Months Ended
	30-Sep-13
	Revenues - external customers:
	Premiums	$	26,698	$	658	$	—	$	—	$	658	$	—		$	27,356
	Services	1,579		193		484		24		701		—			2,280
	Products	2		4		22		797		823		—			825
	Total revenues - external customers	28,279		855		506		821		2,182		—			30,461
	Total revenues - intersegment	—		1,607		291		5,474		7,372		(7,372		)	—
	Investment and other income	130		32		1		—		33		—			163
	Total revenues	$	28,409	$	2,494	$	798	$	6,295	$	9,587	$	(7,372	)	$	30,624
	Earnings from operations	$	2,003	$	280	$	144	$	204	$	628	$	—		$	2,631
	Interest expense	—		—		—		—		—		(178		)	(178		)
	Earnings before income taxes	$	2,003	$	280	$	144	$	204	$	628	$	(178	)	$	2,453
	Three Months Ended
	30-Sep-12
	Revenues - external customers:
	Premiums	$	24,197	$	443	$	—	$	—	$	443	$	—		$	24,640
	Services	1,196		176		431		21		628		—			1,824
	Products	—		4		21		668		693		—			693
	Total revenues - external customers	25,393		623		452		689		1,764		—			27,157
	Total revenues - intersegment	—		1,405		266		3,765		5,436		(5,436		)	—
	Investment and other income	119		26		—		—		26		—			145
	Total revenues	$	25,512	$	2,054	$	718	$	4,454	$	7,226	$	(5,436	)	$	27,302
	Earnings from operations	$	2,202	$	168	$	126	$	114	$	408	$	—		$	2,610
	Interest expense	—		—		—		—		—		(158		)	(158		)
	Earnings before income taxes	$	2,202	$	168	$	126	$	114	$	408	$	(158	)	$	2,452
				Optum
	(in millions)	UnitedHealthcare		OptumHealth		OptumInsight		OptumRx		Total Optum		Corporate and			Consolidated
												Intersegment
												Eliminations
	Nine Months Ended
	30-Sep-13
	Revenues - external customers:
	Premiums	$	79,982	$	1,868	$	—	$	—	$	1,868	$	—		$	81,850
	Services	4,566		576		1,423		71		2,070		—			6,636
	Products	6		14		55		2,250		2,319		—			2,325
	Total revenues - external customers	84,554		2,458		1,478		2,321		6,257		—			90,811
	Total revenues - intersegment	—		4,795		873		14,817		20,485		(20,485		)	—
	Investment and other income	466		94		1		—		95		—			561
	Total revenues	$	85,020	$	7,347	$	2,352	$	17,138	$	26,837	$	(20,485	)	$	91,372
	Earnings from operations	$	5,512	$	731	$	450	$	478	$	1,659	$	—		$	7,171
	Interest expense	—		—		—		—		—		(532		)	(532		)
	Earnings before income taxes	$	5,512	$	731	$	450	$	478	$	1,659	$	(532	)	$	6,639
	Nine Months Ended
	30-Sep-12
	Revenues - external customers:
	Premiums	$	72,592	$	1,288	$	—	$	—	$	1,288	$	—		$	73,880
	Services	3,558		565		1,231		61		1,857		—			5,415
	Products	—		17		48		1,994		2,059		—			2,059
	Total revenues - external customers	76,150		1,870		1,279		2,055		5,204		—			81,354
	Total revenues - intersegment	—		4,064		781		11,725		16,570		(16,570		)	—
	Investment and other income	411		84		—		—		84		—			495
	Total revenues	$	76,561	$	6,018	$	2,060	$	13,780	$	21,858	$	(16,570	)	$	81,849
	Earnings from operations	$	6,173	$	383	$	310	$	287	$	980	$	—		$	7,153
Interest expense	—		—		—		—		—		(459		)	(459		)
Earnings before income taxes	$	6,173	$	383	$	310	$	287	$	980	$	(459	)	$	6,694

Basis_of_Presentation_Policy

Basis of Presentation (Policy)	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Use of Estimates [Policy Text Block]	'
	Use of Estimates
	These Condensed Consolidated Financial Statements include certain amounts based on the Company’s best estimates and judgments. The Company’s most significant estimates relate to medical costs payable, and risk-adjusted and risk-sharing provisions related to revenues, valuation and impairment analysis of goodwill and other intangible assets, estimates of other policy liabilities and other current receivables, valuations of certain investments, and estimates and judgments related to income taxes and contingent liabilities. Certain of these estimates require the application of complex assumptions and judgments, often because they involve matters that are inherently uncertain and will likely change in subsequent periods. The impact of any changes in estimates is included in earnings in the period in which the estimate is adjusted.

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2013
Short-Term and Long-Term Investments [Table Text Block]	'
	A summary of short-term and long-term investments by major security type is as follows:
	(in millions)	Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Gains			Losses
	September 30, 2013
	Debt securities - available-for-sale:
	U.S. government and agency obligations	$	2,466		$	11		$	(12	)	$	2,465
	State and municipal obligations	6,626			181			(57		)	6,750
	Corporate obligations	7,543			144			(53		)	7,634
	U.S. agency mortgage-backed securities	2,028			30			(38		)	2,020
	Non-U.S. agency mortgage-backed securities	660			15			(8		)	667
	Total debt securities - available-for-sale	19,323			381			(168		)	19,536
	Equity securities - available-for-sale	817			4			(13		)	808
	Debt securities - held-to-maturity:
	U.S. government and agency obligations	179			3			—			182
	State and municipal obligations	28			—			—			28
	Corporate obligations	665			—			—			665
	Total debt securities - held-to-maturity	872			3			—			875
	Total investments	$	21,012		$	388		$	(181	)	$	21,219
	December 31, 2012
	Debt securities - available-for-sale:
	U.S. government and agency obligations	$	2,501		$	38		$	(1	)	$	2,538
	State and municipal obligations	6,282			388			(3		)	6,667
	Corporate obligations	6,930			283			(4		)	7,209
	U.S. agency mortgage-backed securities	2,168			70			—			2,238
	Non-U.S. agency mortgage-backed securities	538			36			—			574
	Total debt securities - available-for-sale	18,419			815			(8		)	19,226
	Equity securities - available-for-sale	668			10			(1		)	677
	Debt securities - held-to-maturity:
	U.S. government and agency obligations	168			6			—			174
	State and municipal obligations	30			—			—			30
	Corporate obligations	641			2			—			643
	Total debt securities - held-to-maturity	839			8			—			847
	Total investments	$	19,926		$	833		$	(9	)	$	20,750
Fair Value of Available-for-Sale Investments with Gross Unrealized Losses by Investment Type and Length of Time that Individual Securities have been in a Continuous Unrealized Loss Position [Table Text Block]	'
	The fair value of available-for-sale investments with gross unrealized losses by major security type and length of time that individual securities have been in a continuous unrealized loss position were as follows:
		Less Than 12 Months
		and in Total
	(in millions)	Fair			Gross
		Value			Unrealized
					Losses
	September 30, 2013
	Debt securities - available-for-sale:
	U.S. government and agency obligations	$	676		$	(12	)
	State and municipal obligations	2,114			(57		)
	Corporate obligations	2,730			(53		)
	U.S. agency mortgage-backed securities	927			(38		)
	Non-U.S. agency mortgage-backed securities	332			(8		)
	Total debt securities - available-for-sale	$	6,779		$	(168	)
	Equity securities - available-for-sale	$	137		$	(13	)
	December 31, 2012
	Debt securities - available-for-sale:
	U.S. government and agency obligations	$	183		$	(1	)
	State and municipal obligations	362			(3		)
	Corporate obligations	695			(4		)
	Total debt securities - available-for-sale	$	1,240		$	(8	)
	Equity securities - available-for-sale	$	13		$	(1	)
Net Realized Gains, Included in Investment and Other Income [Table Text Block]	'
	Net realized gains reclassified out of accumulated other comprehensive income were from the following sources:
		Three Months Ended September 30,						Nine Months Ended September 30,
	(in millions)	2013			2012			2013			2012
	Total OTTI	$	(3	)	$	—		$	(7	)	$	(4	)
	Portion of loss recognized in other comprehensive income	—			—			—			—
	Net OTTI recognized in earnings	(3		)	—			(7		)	(4		)
	Gross realized losses from sales	—			(2		)	(3		)	(5		)
	Gross realized gains from sales	34			22			147			118
	Net realized gains (included in Investment and Other Income on the Condensed Consolidated Statements of Operations)	31			20			137			109
	Income tax effect (included in Provision for Income Taxes on the Condensed Consolidated Statements of Operations)	(11		)	(7		)	(50		)	(40		)
	Realized gains, net of taxes	$	20		$	13		$	87		$	69
U.S. Agency Mortgage-Backed Securities [Member]	'
Investments by Contractual Maturity [Table Text Block]	'
	The fair values of the Company’s mortgage-backed securities by credit rating (when multiple credit ratings are available for an individual security, the average of the available ratings is used) and origination date as of September 30, 2013 were as follows:
	(in millions)	AAA			AA			Non-Investment			Total Fair
								Grade			Value
	2013	$	74		$	—		$	—		$	74
	2012	109			—			—			109
	2011	20			—			—			20
	2010	9			—			—			9
	2009	13			—			—			13
	2007	78			—			2			80
	Pre - 2007	349			3			10			362
	U.S. agency mortgage-backed securities	2,020			—			—			2,020
	Total	$	2,672		$	3		$	12		$	2,687
Available-for-sale Securities [Member]	'
Investments by Contractual Maturity [Table Text Block]	'
	The amortized cost and fair value of available-for-sale debt securities as of September 30, 2013, by contractual maturity, were as follows:
	(in millions)	Amortized			Fair
		Cost			Value
	Due in one year or less	$	2,540		$	2,553
	Due after one year through five years	7,219			7,351
	Due after five years through ten years	4,945			5,008
	Due after ten years	1,931			1,937
	U.S. agency mortgage-backed securities	2,028			2,020
	Non-U.S. agency mortgage-backed securities	660			667
	Total debt securities - available-for-sale	$	19,323		$	19,536
Held-to-maturity Securities [Member]	'
Investments by Contractual Maturity [Table Text Block]	'
	The amortized cost and fair value of held-to-maturity debt securities as of September 30, 2013, by contractual maturity, were as follows:
	(in millions)	Amortized			Fair
		Cost			Value
	Due in one year or less	$	445		$	445
	Due after one year through five years	155			155
	Due after five years through ten years	136			138
	Due after ten years	136			137
	Total debt securities - held-to-maturity	$	872		$	875

Fair_Value_Tables

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Financial Assets and Liabilities, Measured at Fair Value Recurring Basis [Table Text Block]	'
	The following table presents a summary of fair value measurements by level and carrying values for items measured at fair value on a recurring basis in the Condensed Consolidated Balance Sheets excluding AARP Program-related assets and liabilities, which are presented in a separate table below:
	(in millions)	Quoted Prices			Other			Unobservable			Total
		in Active			Observable			Inputs			Fair and Carrying
		Markets			Inputs			(Level 3)			Value
		(Level 1)			(Level 2)
	September 30, 2013
	Cash and cash equivalents	$	7,943		$	343		$	—		$	8,286
	Debt securities - available-for-sale:
	U.S. government and agency obligations	1,899			566			—			2,465
	State and municipal obligations	—			6,750			—			6,750
	Corporate obligations	31			7,576			27			7,634
	U.S. agency mortgage-backed securities	—			2,020			—			2,020
	Non-U.S. agency mortgage-backed securities	—			661			6			667
	Total debt securities - available-for-sale	1,930			17,573			33			19,536
	Equity securities - available-for-sale	536			26			246			808
	Currency swap assets	—			22			—			22
	Total assets at fair value	$	10,409		$	17,964		$	279		$	28,652
	Percentage of total assets at fair value	36		%	63		%	1		%	100		%
	Interest rate swap liabilities	$	—		$	79		$	—		$	79
	December 31, 2012
	Cash and cash equivalents	$	7,615		$	791		$	—		$	8,406
	Debt securities - available-for-sale:
	U.S. government and agency obligations	1,752			786			—			2,538
	State and municipal obligations	—			6,667			—			6,667
	Corporate obligations	13			7,185			11			7,209
	U.S. agency mortgage-backed securities	—			2,238			—			2,238
	Non-U.S. agency mortgage-backed securities	—			568			6			574
	Total debt securities - available-for-sale	1,765			17,444			17			19,226
	Equity securities - available-for-sale	450			3			224			677
	Interest rate swap assets	—			14			—			14
	Total assets at fair value	$	9,830		$	18,252		$	241		$	28,323
	Percentage of total assets at fair value	35		%	64		%	1		%	100		%
	Interest rate and currency swap liabilities	$	—		$	14		$	—		$	14
Fair Value Measurements, Nonrecurring [Table Text Block]	'
	The following table presents a summary of fair value measurements by level and carrying values for certain financial instruments not measured at fair value on a recurring basis in the Condensed Consolidated Balance Sheets:
	(in millions)	Quoted Prices			Other			Unobservable			Total			Total Carrying Value
		in Active			Observable			Inputs			Fair
		Markets			Inputs			(Level 3)			Value
		(Level 1)			(Level 2)
	September 30, 2013
	Debt securities - held-to-maturity:
	U.S. government and agency obligations	$	182		$	—		$	—		$	182		$	179
	State and municipal obligations	—			—			28			28			28
	Corporate obligations	47			341			277			665			665
	Total debt securities - held-to-maturity	$	229		$	341		$	305		$	875		$	872
	Long-term debt	$	—		$	16,604		$	—		$	16,604		$	15,723
	December 31, 2012
	Debt securities - held-to-maturity:
	U.S. government and agency obligations	$	174		$	—		$	—		$	174		$	168
	State and municipal obligations	—			1			29			30			30
	Corporate obligations	10			346			287			643			641
	Total debt securities - held-to-maturity	$	184		$	347		$	316		$	847		$	839
	Long-term debt	$	—		$	17,034		$	—		$	17,034		$	15,167
Reconciliation of Assets Measured at Fair Value on a Recurring Basis Using Level 3 Inputs [Table Text Block]	'
	A reconciliation of the beginning and ending balances of assets measured at fair value on a recurring basis using Level 3 inputs is as follows:
		Three Months Ended									Nine Months Ended
	(in millions)	Debt			Equity			Total			Debt			Equity			Total
		Securities			Securities						Securities			Securities
	September 30, 2013
	Balance at beginning of period	$	38		$	245		$	283		$	17		$	224		$	241
	Purchases	3			9			12			25			51			76
	Sales	(7		)	—			(7		)	(7		)	(21		)	(28		)
	Net unrealized losses in accumulated other comprehensive income	—			(7		)	(7		)	(1		)	(13		)	(14		)
	Net realized (losses) gains in investment and other income	(1		)	(1		)	(2		)	(1		)	5			4
	Balance at end of period	$	33		$	246		$	279		$	33		$	246		$	279
	September 30, 2012
	Balance at beginning of period	$	7		$	228		$	235		$	208		$	209		$	417
	Purchases	—			2			2			—			53			53
	Sales	—			(11		)	(11		)	—			(20		)	(20		)
	Settlements	(1		)	—			(1		)	(1		)	—			(1		)
	Net unrealized losses in accumulated other comprehensive income	—			(9		)	(9		)	—			(12		)	(12		)
	Net realized gains in investment and other income	—			8			8			—			9			9
	Transfers to held-to-maturity	—			—			—			(201		)	(21		)	(222		)
	Balance at end of period	$	6		$	218		$	224		$	6		$	218		$	224
Fair Value Inputs, Assets, Quantitative Information [Table Text Block]	'
	The following table presents quantitative information regarding unobservable inputs that were significant to the valuation of assets measured at fair value on a recurring basis using Level 3 inputs:
								Range
	(in millions)	Fair Value			Valuation Technique		Unobservable Input	Low		High
	September 30, 2013
	Equity securities - available-for-sale
	Venture capital portfolios	$	210		Market approach - comparable companies		Revenue multiple	1		10
							EBITDA multiple	7		10
		36			Market approach - recent transactions		Inactive market transactions	N/A		N/A
	Total equity securities	$	246
	available-for-sale
Aarp Program [Member]	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'
Financial Assets and Liabilities, Measured at Fair Value Recurring Basis [Table Text Block]	'
	(in millions)	Quoted Prices			Other			Total
		in Active			Observable			Fair and Carrying
		Markets			Inputs			Value
		(Level 1)			(Level 2)
	September 30, 2013
	Cash and cash equivalents	$	227		$	—		$	227
	Debt securities:
	U.S. government and agency obligations	487			271			758
	State and municipal obligations	—			61			61
	Corporate obligations	—			1,077			1,077
	U.S. agency mortgage-backed securities	—			428			428
	Non-U.S. agency mortgage-backed securities	—			139			139
	Total debt securities	487			1,976			2,463
	Equity securities - available-for-sale	—			4			4
	Total assets at fair value	$	714		$	1,980		$	2,694
	Other liabilities	$	8		$	18		$	26
	December 31, 2012
	Cash and cash equivalents	$	230		$	—		$	230
	Debt securities:
	U.S. government and agency obligations	545			244			789
	State and municipal obligations	—			51			51
	Corporate obligations	—			1,118			1,118
	U.S. agency mortgage-backed securities	—			427			427
	Non-U.S. agency mortgage-backed securities	—			155			155
	Total debt securities	545			1,995			2,540
	Equity securities - available-for-sale	—			3			3
	Total assets at fair value	$	775		$	1,998		$	2,773
	Other liabilities	$	23		$	58		$	81

Medicare_Part_D_Pharmacy_Benef1

Medicare Part D Pharmacy Benefits (Tables)	9 Months Ended
	Sep. 30, 2013
Schedule of Other Current Receivables and Other Policy Liabilities Associated with Medicare Part D Program [Table Text Block]	'
	The Condensed Consolidated Balance Sheets include the following amounts associated with the Medicare Part D program:
		September 30, 2013						December 31, 2012
	(in millions)	Subsidies		Drug Discount		Risk-Share		Subsidies		Drug Discount		Risk-Share
	Other current receivables	$	638	$	523	$	—	$	461	$	314	$	—
	Other policy liabilities	—		380		469		—		319		438

Medical_Cost_Development_Medic

Medical Cost Development Medical Cost Development (Tables)	9 Months Ended
	Sep. 30, 2013
Medical Cost Development [Abstract]	'
Changes In Provision For Insured Events Related To Current And Prior Year [Table Text Block]	'
	The following table provides details of the Company's net favorable medical cost development:
		Three Months Ended September 30,				Nine Months Ended September 30,
	(in millions)	2013		2012		2013		2012
	Related to Prior Years	$	180	$	170	$	580	$	790
	Related to Current Year	110		220		N/A		N/A

Commercial_Paper_and_LongTerm_1

Commercial Paper and Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Commercial Paper and Long-Term Debt [Table Text Block]	'
	Commercial paper and long-term debt consisted of the following:
			September 30, 2013									December 31, 2012
	(in millions, except percentages)		Par			Carrying			Fair			Par			Carrying		Fair
			Value			Value			Value			Value			Value		Value
	Commercial Paper		$	1,060		$	1,060		$	1,060		$	1,587		$	1,587	$	1,587
	4.875% senior unsecured notes due February 2013		—			—			—			534			534		536
	4.875% senior unsecured notes due April 2013		—			—			—			409			411		413
	4.750% senior unsecured notes due February 2014		172			175			175			172			178		180
	5.000% senior unsecured notes due August 2014		389			401			405			389			411		414
	Senior unsecured floating-rate notes due August 2014		250			250			250			—			—		—
	4.875% senior unsecured notes due March 2015 (a)		416			435			440			416			444		453
	0.850% senior unsecured notes due October 2015 (a)		625			624			627			625			623		627
	5.375% senior unsecured notes due March 2016 (a)		601			645			663			601			660		682
	1.875% senior unsecured notes due November 2016		400			398			409			400			397		412
	5.360% senior unsecured notes due November 2016		95			95			108			95			95		110
	6.000% senior unsecured notes due June 2017		441			481			509			441			489		528
	1.400% senior unsecured notes due October 2017 (a)		625			614			617			625			622		626
	6.000% senior unsecured notes due November 2017		156			168			178			156			170		191
	6.000% senior unsecured notes due February 2018		1,100			1,117			1,282			1,100			1,120		1,339
	1.625% senior unsecured notes due March 2019		500			498			482			—			—		—
	3.875% senior unsecured notes due October 2020		450			443			474			450			442		499
	4.700% senior unsecured notes due February 2021		400			416			437			400			417		466
	3.375% senior unsecured notes due November 2021 (a)		500			481			499			500			512		533
	2.875% senior unsecured notes due March 2022		1,100			1,005			1,045			1,100			998		1,128
	0.000% senior unsecured notes due November 2022		15			9			10			15			9		11
	2.750% senior unsecured notes due February 2023 (a)		625			576			582			625			619		631
	2.875% senior unsecured notes due March 2023		750			747			706			—			—		—
	5.800% senior unsecured notes due March 2036		850			845			940			850			845		1,025
	6.500% senior unsecured notes due June 2037		500			495			604			500			495		659
	6.625% senior unsecured notes due November 2037		650			645			795			650			645		860
	6.875% senior unsecured notes due February 2038		1,100			1,084			1,381			1,100			1,084		1,510
	5.700% senior unsecured notes due October 2040		300			298			332			300			298		364
	5.950% senior unsecured notes due February 2041		350			348			401			350			348		440
	4.625% senior unsecured notes due November 2041		600			593			572			600			593		641
	4.375% senior unsecured notes due March 2042		502			486			462			502			486		521
	3.950% senior unsecured notes due October 2042		625			611			536			625			611		622
	4.250% senior unsecured notes due March 2043		750			740			683			—			—		—
	Total U.S. dollar denominated debt		16,897			16,783			17,664			16,117			16,143		18,008
	Cetip Interbank Deposit Rate (CDI) + 1.3% Subsidiary floating debt due October 2013		—			—			—			147			148		150
	CDI + 1.45% Subsidiary floating debt due October 2014		—			—			—			147			149		150
	110% CDI Subsidiary floating debt due December 2014		—			—			—			147			151		147
	CDI + 1.6% Subsidiary floating debt due October 2015		—			—			—			74			76		76
	Brazilian Extended National Consumer Price Index (IPCA) + 7.61% Subsidiary floating debt due October 2015		—			—			—			73			87		90
	Total Brazilian real denominated debt (in U.S. dollars)		—			—			—			588			611		613
	Total commercial paper and long-term debt		$	16,897		$	16,783		$	17,664		$	16,705		$	16,754	$	18,621
	(a)	Fixed-rate debt instruments hedged with interest rate swap contracts. See below for more information on the Company’s interest rate swaps.
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	'
	Type of Fair Value Hedge		Notional Amount			Fair Value			Balance Sheet Location
			(in billions)			(in millions)
	September 30, 2013
	Interest rate swap contracts		$	3.4		$	79		Other liabilities
	31-Dec-12
	Interest rate swap contracts		$	2.8		$	14		Other assets
						11			Other liabilities
Derivative Instruments, Gain (Loss) [Table Text Block]	'
	The following table provides a summary of the effect of changes in fair value of fair value hedges on the Company’s Condensed Consolidated Statements of Operations:
			Three Months Ended September 30,						Nine Months Ended September 30,
	(in millions)		2013			2012			2013			2012
	Hedge (interest rate swap) gain (loss) recognized in interest expense		$	9		$	5		$	(82	)	$	17
	Hedged item (long-term debt) (loss) gain recognized in interest expense		(9		)	(5		)	82			(17		)
	Net impact on the Company’s Condensed Consolidated Statements of Operations		$	—		$	—		$	—		$	—

Shareholders_Equity_Shareholde1

Shareholders' Equity Shareholder's Equity (Tables)	9 Months Ended
	Sep. 30, 2013
Shareholders' Equity [Abstract]	'
Schedule Of Dividends Paid [Table Text Block]	'
	The following table provides details of the Company’s 2013 dividend payments:
	Payment Date	Amount per Share		Total Amount Paid
				(in millions)
	26-Mar-13	$	0.2125	$	216
	26-Jun-13	0.28		281
	24-Sep-13	0.28		280

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock Option and SAR Activity [Table Text Block]	'
	Stock option and SAR activity for the nine months ended September 30, 2013 is summarized in the table below:
		Shares			Weighted-				Weighted-		Aggregate
					Average				Average		Intrinsic Value
					Exercise				Remaining
					Price				Contractual Life
		(in millions)							(in years)		(in millions)
	Outstanding at beginning of period	63			$	45
	Granted	8			58
	Exercised	(25	)		43
	Forfeited	(2	)		55
	Outstanding at end of period	44			48				4.6		$	1,054
	Exercisable at end of period	33			46				3.2		840
	Vested and expected to vest, end of period	43			48				4.6		1,043
Restricted Share Activity [Table Text Block]	'
	Restricted share activity for the nine months ended September 30, 2013 is summarized in the table below:
	(shares in millions)		Shares			Weighted-Average
						Grant Date
						Fair Value
						per Share
	Nonvested at beginning of period		9			$	46
	Granted		3			58
	Forfeited		(1	)		50
	Nonvested at end of period		11			50
Other Share-Based Compensation Data [Table Text Block]	'
	Other Share-Based Compensation Data
	(in millions, except per share amounts)		Three Months Ended September 30,							Nine Months Ended September 30,
			2013				2012			2013			2012
	Stock Options and SARs
	Weighted-average grant date fair value of shares granted, per share		$	23			$	16		$	19		$	18
	Total intrinsic value of stock options and SARs exercised		182				44			507			442
	Restricted Shares
	Weighted-average grant date fair value of shares granted, per share		72				51			58			52
	Total fair value of restricted shares vested		—				5			—			357
	Share-Based Compensation Items
	Share-based compensation expense, before tax		79				87			255			329
	Share-based compensation expense, net of tax effects		67				70			174			230
	Income tax benefit realized from share-based award exercises		62				14			178			288
	(in millions, except years)		September 30, 2013
	Unrecognized compensation expense related to share awards		$	374
	Weighted-average years to recognize compensation expense		1.3
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]	'
	The principal assumptions the Company used in calculating grant-date fair value for stock options and SARs were as follows:
			Three Months Ended September 30,				Nine Months Ended September 30,
			2013		2012		2013		2012
	Risk-free interest rate		1.60%		0.70%		1.0% - 1.6%		0.7% - 0.9%
	Expected volatility		41.80%		44.00%		41.8% - 43.0%		43.4% - 44.0%
	Expected dividend yield		1.50%		1.70%		1.4% - 1.5%		1.2% - 1.7%
	Forfeiture rate		5.00%		5.00%		5.00%		5.00%
	Expected life in years		5.3		5.3		5.3		5.3 - 5.6

Segment_Financial_Information_

Segment Financial Information (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment Financial Information [Table Text Block]	'
	Corporate and intersegment elimination amounts are presented to reconcile the reportable segment results to the consolidated results. The following table presents the reportable segment financial information:
				Optum
	(in millions)	UnitedHealthcare		OptumHealth		OptumInsight		OptumRx		Total Optum		Corporate and			Consolidated
												Intersegment
												Eliminations
	Three Months Ended
	30-Sep-13
	Revenues - external customers:
	Premiums	$	26,698	$	658	$	—	$	—	$	658	$	—		$	27,356
	Services	1,579		193		484		24		701		—			2,280
	Products	2		4		22		797		823		—			825
	Total revenues - external customers	28,279		855		506		821		2,182		—			30,461
	Total revenues - intersegment	—		1,607		291		5,474		7,372		(7,372		)	—
	Investment and other income	130		32		1		—		33		—			163
	Total revenues	$	28,409	$	2,494	$	798	$	6,295	$	9,587	$	(7,372	)	$	30,624
	Earnings from operations	$	2,003	$	280	$	144	$	204	$	628	$	—		$	2,631
	Interest expense	—		—		—		—		—		(178		)	(178		)
	Earnings before income taxes	$	2,003	$	280	$	144	$	204	$	628	$	(178	)	$	2,453
	Three Months Ended
	30-Sep-12
	Revenues - external customers:
	Premiums	$	24,197	$	443	$	—	$	—	$	443	$	—		$	24,640
	Services	1,196		176		431		21		628		—			1,824
	Products	—		4		21		668		693		—			693
	Total revenues - external customers	25,393		623		452		689		1,764		—			27,157
	Total revenues - intersegment	—		1,405		266		3,765		5,436		(5,436		)	—
	Investment and other income	119		26		—		—		26		—			145
	Total revenues	$	25,512	$	2,054	$	718	$	4,454	$	7,226	$	(5,436	)	$	27,302
	Earnings from operations	$	2,202	$	168	$	126	$	114	$	408	$	—		$	2,610
	Interest expense	—		—		—		—		—		(158		)	(158		)
	Earnings before income taxes	$	2,202	$	168	$	126	$	114	$	408	$	(158	)	$	2,452
				Optum
	(in millions)	UnitedHealthcare		OptumHealth		OptumInsight		OptumRx		Total Optum		Corporate and			Consolidated
												Intersegment
												Eliminations
	Nine Months Ended
	30-Sep-13
	Revenues - external customers:
	Premiums	$	79,982	$	1,868	$	—	$	—	$	1,868	$	—		$	81,850
	Services	4,566		576		1,423		71		2,070		—			6,636
	Products	6		14		55		2,250		2,319		—			2,325
	Total revenues - external customers	84,554		2,458		1,478		2,321		6,257		—			90,811
	Total revenues - intersegment	—		4,795		873		14,817		20,485		(20,485		)	—
	Investment and other income	466		94		1		—		95		—			561
	Total revenues	$	85,020	$	7,347	$	2,352	$	17,138	$	26,837	$	(20,485	)	$	91,372
	Earnings from operations	$	5,512	$	731	$	450	$	478	$	1,659	$	—		$	7,171
	Interest expense	—		—		—		—		—		(532		)	(532		)
	Earnings before income taxes	$	5,512	$	731	$	450	$	478	$	1,659	$	(532	)	$	6,639
	Nine Months Ended
	30-Sep-12
	Revenues - external customers:
	Premiums	$	72,592	$	1,288	$	—	$	—	$	1,288	$	—		$	73,880
	Services	3,558		565		1,231		61		1,857		—			5,415
	Products	—		17		48		1,994		2,059		—			2,059
	Total revenues - external customers	76,150		1,870		1,279		2,055		5,204		—			81,354
	Total revenues - intersegment	—		4,064		781		11,725		16,570		(16,570		)	—
	Investment and other income	411		84		—		—		84		—			495
	Total revenues	$	76,561	$	6,018	$	2,060	$	13,780	$	21,858	$	(16,570	)	$	81,849
	Earnings from operations	$	6,173	$	383	$	310	$	287	$	980	$	—		$	7,153
	Interest expense	—		—		—		—		—		(459		)	(459		)
	Earnings before income taxes	$	6,173	$	383	$	310	$	287	$	980	$	(459	)	$	6,694

Investments_Narrative_Details

Investments (Narrative) (Details)	Sep. 30, 2013
	positions
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	5,800
Total number of security positions	19,500

Investments_ShortTerm_and_Long

Investments (Short-Term and Long-Term Investments) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Available-for-sale Securities, Debt Securities	$19,536	'
Available-for-sale Equity Securities, Amortized Cost Basis	817	668
Securities, Available for sale Equity Securities, Gross Unrealized Gains	4	10
Securities, Available for sale Equity Securities, Gross Unrealized Losses	-13	-1
Available-for-sale Securities, Equity Securities	808	677
Held-to-maturity securities, Amortized Cost	872	839
Securities, Held to maturity, Unrecognized Holding Gain	3	8
Securities, Held To Maturity, Unrecognized Holding Loss	0	0
Total debt securities - held-to-maturity, Fair Value	875	847
Total investments, Amortized Cost	21,012	19,926
Total investments, Gross Unrealized Gains	388	833
Total investments: Gross Unrealized Losses	-181	-9
Investments, Fair Value Disclosure	21,219	20,750
Debt Securities [Member]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	19,323	18,419
Securities, Available for sale Debt Securities, Gross Unrealized Gains	381	815
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	-168	-8
Available-for-sale Securities, Debt Securities	19,536	19,226
U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	2,466	2,501
Securities, Available for sale Debt Securities, Gross Unrealized Gains	11	38
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	-12	-1
Available-for-sale Securities, Debt Securities	2,465	2,538
Held-to-maturity securities, Amortized Cost	179	168
Securities, Held to maturity, Unrecognized Holding Gain	3	6
Securities, Held To Maturity, Unrecognized Holding Loss	0	0
Total debt securities - held-to-maturity, Fair Value	182	174
State and Municipal Obligations [Member]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	6,626	6,282
Securities, Available for sale Debt Securities, Gross Unrealized Gains	181	388
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	-57	-3
Available-for-sale Securities, Debt Securities	6,750	6,667
Held-to-maturity securities, Amortized Cost	28	30
Securities, Held to maturity, Unrecognized Holding Gain	0	0
Securities, Held To Maturity, Unrecognized Holding Loss	0	0
Total debt securities - held-to-maturity, Fair Value	28	30
Corporate Obligations [Member]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	7,543	6,930
Securities, Available for sale Debt Securities, Gross Unrealized Gains	144	283
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	-53	-4
Available-for-sale Securities, Debt Securities	7,634	7,209
Held-to-maturity securities, Amortized Cost	665	641
Securities, Held to maturity, Unrecognized Holding Gain	0	2
Securities, Held To Maturity, Unrecognized Holding Loss	0	0
Total debt securities - held-to-maturity, Fair Value	665	643
U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	2,028	2,168
Securities, Available for sale Debt Securities, Gross Unrealized Gains	30	70
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	-38	0
Available-for-sale Securities, Debt Securities	2,020	2,238
Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Debt Securities, Amortized Cost Basis	660	538
Securities, Available for sale Debt Securities, Gross Unrealized Gains	15	36
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	-8	0
Available-for-sale Securities, Debt Securities	$667	$574

Investments_Fair_Value_of_Mort

Investments (Fair Value of Mortgage-Backed Securities by Credit Rating Origination) (Details) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Mortgage-backed securities	$2,687
2013 [Member]	'
Mortgage-backed securities	74
2012 [Member]	'
Mortgage-backed securities	109
2011 [Member]	'
Mortgage-backed securities	20
2010 [Member]	'
Mortgage-backed securities	9
2009 [Member]	'
Mortgage-backed securities	13
2007 [Member]	'
Mortgage-backed securities	80
Pre 2007[Member]	'
Mortgage-backed securities	362
U.S. Agency Mortgage-Backed Securities [Member]	'
Mortgage-backed securities	2,020
AAA [Member]	'
Mortgage-backed securities	2,672
AAA [Member] | 2013 [Member]	'
Mortgage-backed securities	74
AAA [Member] | 2012 [Member]	'
Mortgage-backed securities	109
AAA [Member] | 2011 [Member]	'
Mortgage-backed securities	20
AAA [Member] | 2010 [Member]	'
Mortgage-backed securities	9
AAA [Member] | 2009 [Member]	'
Mortgage-backed securities	13
AAA [Member] | 2007 [Member]	'
Mortgage-backed securities	78
AAA [Member] | Pre 2007[Member]	'
Mortgage-backed securities	349
AAA [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'
Mortgage-backed securities	2,020
AA [Member]	'
Mortgage-backed securities	3
AA [Member] | 2013 [Member]	'
Mortgage-backed securities	0
AA [Member] | 2012 [Member]	'
Mortgage-backed securities	0
AA [Member] | 2011 [Member]	'
Mortgage-backed securities	0
AA [Member] | 2010 [Member]	'
Mortgage-backed securities	0
AA [Member] | 2009 [Member]	'
Mortgage-backed securities	0
AA [Member] | 2007 [Member]	'
Mortgage-backed securities	0
AA [Member] | Pre 2007[Member]	'
Mortgage-backed securities	3
AA [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'
Mortgage-backed securities	0
External Credit Rating, Non Investment Grade [Member]	'
Mortgage-backed securities	12
External Credit Rating, Non Investment Grade [Member] | 2013 [Member]	'
Mortgage-backed securities	0
External Credit Rating, Non Investment Grade [Member] | 2012 [Member]	'
Mortgage-backed securities	0
External Credit Rating, Non Investment Grade [Member] | 2011 [Member]	'
Mortgage-backed securities	0
External Credit Rating, Non Investment Grade [Member] | 2010 [Member]	'
Mortgage-backed securities	0
External Credit Rating, Non Investment Grade [Member] | 2009 [Member]	'
Mortgage-backed securities	0
External Credit Rating, Non Investment Grade [Member] | 2007 [Member]	'
Mortgage-backed securities	2
External Credit Rating, Non Investment Grade [Member] | Pre 2007[Member]	'
Mortgage-backed securities	10
External Credit Rating, Non Investment Grade [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'
Mortgage-backed securities	$0

Investments_Amortized_Cost_and

Investments (Amortized Cost and Fair Value of Available-for-Sale Debt Securities by Contractual Maturity) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Due in one year or less, Amortized Cost	$2,540	'
Due after one year through five years, Amortized Cost	7,219	'
Due after five years through ten years, Amortized Cost	4,945	'
Due after ten years, Amortized Cost	1,931	'
Total debt securities - available-for-sale, Amortized Cost	19,323	'
Due in one year or less, Fair Value	2,553	'
Due after one year through five years, Fair Value	7,351	'
Due after five years through ten years, Fair Value	5,008	'
Due after ten years, Fair Value	1,937	'
Available-for-sale Securities, Debt Securities	19,536	'
U.S. Agency Mortgage-Backed Securities [Member]	'	'
Mortgage-backed securities, Amortized Cost	2,028	'
Mortgage-backed securities, Fair Value	2,020	'
Available-for-sale Securities, Debt Securities	2,020	2,238
Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Mortgage-backed securities, Amortized Cost	660	'
Mortgage-backed securities, Fair Value	667	'
Available-for-sale Securities, Debt Securities	$667	$574

Investments_Amortized_Cost_and1

Investments (Amortized Cost and Fair Value of Held-To-Maturity Debt Securities by Contractual Maturity) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Schedule of Held-to-maturity Securities [Line Items]	'	'
Due in one year or less, Amortized Cost	$445	'
Due after one year through five years, Amortized Cost	155	'
Due after five years through ten years, Amortized Cost	136	'
Due after ten years, Amortized Cost	136	'
Total debt securities - held-to-maturity, Amortized Cost	872	839
Due in one year or less, Fair Value	445	'
Due after one year through five years, Fair Value	155	'
Due after five years through ten years, Fair Value	138	'
Due after ten years, Fair Value	137	'
Total debt securities - held-to-maturity, Fair Value	$875	$847

Investments_Fair_Value_of_Avai

Investments (Fair Value of Available-For-Sale Investments with Gross Unrealized Losses by Investment Type and Length of Time That Individual Securities Have Been in a Continuous Unrealized Loss Position) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Debt Securities [Member]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$6,779	$1,240
Less Than 12 Months, Gross Unrealized Losses	-168	-8
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	6,779	1,240
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	-168	-8
US Treasury and Government [Member]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	676	183
Less Than 12 Months, Gross Unrealized Losses	-12	-1
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	676	183
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	-12	-1
State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	2,114	362
Less Than 12 Months, Gross Unrealized Losses	-57	-3
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,114	362
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	-57	-3
Corporate Obligations [Member]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	2,730	695
Less Than 12 Months, Gross Unrealized Losses	-53	-4
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	2,730	695
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	-53	-4
U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	927	'
Less Than 12 Months, Gross Unrealized Losses	-38	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	927	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	-38	'
Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	332	'
Less Than 12 Months, Gross Unrealized Losses	-8	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	332	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	-8	'
Equity Securities [Member]	'	'
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	137	13
Less Than 12 Months, Gross Unrealized Losses	-13	-1
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	137	13
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	($13)	($1)

Investments_Net_Realized_Gains

Investments (Net Realized Gains) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Income tax effect (included in Provision for Income Taxes on the Condensed Consolidated Statements of Operations)	($883)	($895)	($2,393)	($2,412)
Accumulated Net Unrealized Investment Gain (Loss) [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Total OTTI	-3	0	-7	-4
Portion of loss recognized in other comprehensive income	0	0	0	0
Net OTTI recognized in earnings	-3	0	-7	-4
Gross realized losses from sales	0	-2	-3	-5
Gross realized gains from sales	34	22	147	118
Net realized gains (included in Investment and Other Income on the Condensed Consolidated Statements of Operations)	31	20	137	109
Income tax effect (included in Provision for Income Taxes on the Condensed Consolidated Statements of Operations)	-11	-7	-50	-40
Realized gains, net of taxes	$20	$13	$87	$69

Fair_Value_Narrative_Details

Fair Value (Narrative) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Transfers from level 1 to level 2-Assets	$0	$0
Transfers from level 1 to level 2-Liabilities	0	0
Transfer from level 2 to level 1-Assets	0	0
Transfer from level 2 to level 1-Liabilities	0	0
Transfers Into Level 3	0	0
Transfers out of Level 3	0	0
Fair Value, Measurements, Nonrecurring [Member]	'	'
Significant fair value adjustments for assets and liabilities measured on a nonrecurring basis	0	0
Fair Value, Measurements, Recurring [Member] | Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Available-for-sale Securities	$33	'

Fair_Value_Financial_Assets_an

Fair Value (Financial Assets and Liabilities, Excluding AARP, Measured at Fair Value on a Recurring Basis) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Cash and cash equivalents	$8,286	$8,406
Available-for-sale Securities, Debt Securities	19,536	'
Available-for-sale Securities, Equity Securities	808	677
Currency swap assets	22	'
Interest rate swap assets	'	14
Total assets at fair value	28,652	28,323
Percentage of total assets at fair value	100.00%	100.00%
Interest rate and currency swap liabilities	'	14
Interest rate swap liabilities	79	'
Debt Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	19,536	19,226
U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	2,465	2,538
State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	6,750	6,667
Corporate Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	7,634	7,209
U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	2,020	2,238
Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	667	574
Quoted Prices in Active Markets (Level 1) [Member]	'	'
Cash and cash equivalents	7,943	7,615
Available-for-sale Securities, Equity Securities	536	450
Currency swap assets	0	'
Interest rate swap assets	'	0
Total assets at fair value	10,409	9,830
Percentage of total assets at fair value	36.00%	35.00%
Interest rate and currency swap liabilities	'	0
Interest rate swap liabilities	0	'
Quoted Prices in Active Markets (Level 1) [Member] | Debt Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	1,930	1,765
Quoted Prices in Active Markets (Level 1) [Member] | U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	1,899	1,752
Quoted Prices in Active Markets (Level 1) [Member] | State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Quoted Prices in Active Markets (Level 1) [Member] | Corporate Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	31	13
Quoted Prices in Active Markets (Level 1) [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Quoted Prices in Active Markets (Level 1) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Other Observable Inputs (Level 2) [Member]	'	'
Cash and cash equivalents	343	791
Available-for-sale Securities, Equity Securities	26	3
Currency swap assets	22	'
Interest rate swap assets	'	14
Total assets at fair value	17,964	18,252
Percentage of total assets at fair value	63.00%	64.00%
Interest rate and currency swap liabilities	'	14
Interest rate swap liabilities	79	'
Other Observable Inputs (Level 2) [Member] | Debt Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	17,573	17,444
Other Observable Inputs (Level 2) [Member] | U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	566	786
Other Observable Inputs (Level 2) [Member] | State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	6,750	6,667
Other Observable Inputs (Level 2) [Member] | Corporate Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	7,576	7,185
Other Observable Inputs (Level 2) [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	2,020	2,238
Other Observable Inputs (Level 2) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	661	568
Unobservable Inputs (Level 3) [Member]	'	'
Cash and cash equivalents	0	0
Available-for-sale Securities, Equity Securities	246	224
Currency swap assets	0	'
Interest rate swap assets	'	0
Total assets at fair value	279	241
Percentage of total assets at fair value	1.00%	1.00%
Interest rate and currency swap liabilities	'	0
Interest rate swap liabilities	0	'
Unobservable Inputs (Level 3) [Member] | Debt Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	33	17
Unobservable Inputs (Level 3) [Member] | U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Unobservable Inputs (Level 3) [Member] | State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Unobservable Inputs (Level 3) [Member] | Corporate Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	27	11
Unobservable Inputs (Level 3) [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Unobservable Inputs (Level 3) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	$6	$6

Fair_Value_Financial_Assets_an1

Fair Value (Financial Assets and Liabilities, Excluding AARP, Not Measured at Fair Value on a Recurring Basis) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Debt securities - held-to-maturity	$872	$839
U.S. Government and Agency Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'
Debt securities - held-to-maturity	182	174
U.S. Government and Agency Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]	'	'
Debt securities - held-to-maturity	182	174
U.S. Government and Agency Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]	'	'
Debt securities - held-to-maturity	0	0
U.S. Government and Agency Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]	'	'
Debt securities - held-to-maturity	0	0
U.S. Government and Agency Obligations [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]	'	'
Debt securities - held-to-maturity	179	168
State and Municipal Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'
Debt securities - held-to-maturity	28	30
State and Municipal Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]	'	'
Debt securities - held-to-maturity	0	0
State and Municipal Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]	'	'
Debt securities - held-to-maturity	0	1
State and Municipal Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]	'	'
Debt securities - held-to-maturity	28	29
State and Municipal Obligations [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]	'	'
Debt securities - held-to-maturity	28	30
Corporate Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'
Debt securities - held-to-maturity	665	643
Corporate Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]	'	'
Debt securities - held-to-maturity	47	10
Corporate Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]	'	'
Debt securities - held-to-maturity	341	346
Corporate Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]	'	'
Debt securities - held-to-maturity	277	287
Corporate Obligations [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]	'	'
Debt securities - held-to-maturity	665	641
Debt Securities [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'
Debt securities - held-to-maturity	875	847
Debt Securities [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]	'	'
Debt securities - held-to-maturity	229	184
Debt Securities [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]	'	'
Debt securities - held-to-maturity	341	347
Debt Securities [Member] | Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]	'	'
Debt securities - held-to-maturity	305	316
Debt Securities [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]	'	'
Debt securities - held-to-maturity	872	839
Senior Notes [Member] | Fair Value, Measurements, Nonrecurring [Member]	'	'
Debt Instrument, Fair Value Disclosure	16,604	17,034
Senior Notes [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]	'	'
Debt Instrument, Fair Value Disclosure	0	0
Senior Notes [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]	'	'
Debt Instrument, Fair Value Disclosure	16,604	17,034
Senior Notes [Member] | Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]	'	'
Debt Instrument, Fair Value Disclosure	0	0
Senior Notes [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]	'	'
Debt Instrument, Fair Value Disclosure	$15,723	$15,167

Fair_Value_Reconciliation_of_A

Fair Value (Reconciliation of Assets Measured at Fair Value on a Recurring Basis Using Level 3 Inputs) (Details) (Fair Value, Measurements, Recurring [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Balance at beginning of period	$283	$235	$241	$417
Purchases	12	2	76	53
Sales	-7	-11	-28	-20
Settlements	'	-1	'	-1
Net unrealized losses in accumulated other comprehensive income	-7	-9	-14	-12
Net realized (losses) gains in investment and other income	-2	8	4	9
Transfers to held-to-maturity	'	0	'	-222
Balance at end of period	279	224	279	224
Debt Securities [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Balance at beginning of period	38	7	17	208
Purchases	3	0	25	0
Sales	-7	0	-7	0
Settlements	'	-1	'	-1
Net unrealized losses in accumulated other comprehensive income	0	0	-1	0
Net realized (losses) gains in investment and other income	-1	0	-1	0
Transfers to held-to-maturity	'	0	'	-201
Balance at end of period	33	6	33	6
Equity Securities [Member]	'	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]	'	'	'	'
Balance at beginning of period	245	228	224	209
Purchases	9	2	51	53
Sales	0	-11	-21	-20
Settlements	'	0	'	0
Net unrealized losses in accumulated other comprehensive income	-7	-9	-13	-12
Net realized (losses) gains in investment and other income	-1	8	5	9
Transfers to held-to-maturity	'	0	'	-21
Balance at end of period	$246	$218	$246	$218

Fair_Value_Assets_and_Liabilit

Fair Value (Assets and Liabilities measured at fair value on a recurring basis) (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Cash and cash equivalents	$8,286	$8,406
Available-for-sale Securities, Debt Securities	19,536	'
Available-for-sale Securities	808	677
Total assets at fair value	28,652	28,323
Debt Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	19,536	19,226
U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	2,465	2,538
State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	6,750	6,667
Corporate Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	7,634	7,209
U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	2,020	2,238
Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	667	574
Quoted Prices in Active Markets (Level 1) [Member]	'	'
Cash and cash equivalents	7,943	7,615
Available-for-sale Securities	536	450
Total assets at fair value	10,409	9,830
Quoted Prices in Active Markets (Level 1) [Member] | Debt Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	1,930	1,765
Quoted Prices in Active Markets (Level 1) [Member] | U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	1,899	1,752
Quoted Prices in Active Markets (Level 1) [Member] | State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Quoted Prices in Active Markets (Level 1) [Member] | Corporate Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	31	13
Quoted Prices in Active Markets (Level 1) [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Quoted Prices in Active Markets (Level 1) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Other Observable Inputs (Level 2) [Member]	'	'
Cash and cash equivalents	343	791
Available-for-sale Securities	26	3
Total assets at fair value	17,964	18,252
Other Observable Inputs (Level 2) [Member] | Debt Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	17,573	17,444
Other Observable Inputs (Level 2) [Member] | U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	566	786
Other Observable Inputs (Level 2) [Member] | State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	6,750	6,667
Other Observable Inputs (Level 2) [Member] | Corporate Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	7,576	7,185
Other Observable Inputs (Level 2) [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	2,020	2,238
Other Observable Inputs (Level 2) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	661	568
Fair Value, Measurements, Recurring [Member] | AARP Program [Member]	'	'
Cash and cash equivalents	227	230
Available-for-sale Securities	4	3
Total assets at fair value	2,694	2,773
Other liabilities	26	81
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Debt Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	2,463	2,540
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	758	789
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	61	51
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Corporate Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	1,077	1,118
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	428	427
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	139	155
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Quoted Prices in Active Markets (Level 1) [Member]	'	'
Cash and cash equivalents	227	230
Available-for-sale Securities	0	0
Total assets at fair value	714	775
Other liabilities	8	23
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Quoted Prices in Active Markets (Level 1) [Member] | Debt Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	487	545
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Quoted Prices in Active Markets (Level 1) [Member] | U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	487	545
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Quoted Prices in Active Markets (Level 1) [Member] | State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Quoted Prices in Active Markets (Level 1) [Member] | Corporate Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Quoted Prices in Active Markets (Level 1) [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Quoted Prices in Active Markets (Level 1) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	0	0
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Other Observable Inputs (Level 2) [Member]	'	'
Cash and cash equivalents	0	0
Available-for-sale Securities	4	3
Total assets at fair value	1,980	1,998
Other liabilities	18	58
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Other Observable Inputs (Level 2) [Member] | Debt Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	1,976	1,995
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Other Observable Inputs (Level 2) [Member] | U.S. Government and Agency Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	271	244
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Other Observable Inputs (Level 2) [Member] | State and Municipal Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	61	51
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Other Observable Inputs (Level 2) [Member] | Corporate Obligations [Member]	'	'
Available-for-sale Securities, Debt Securities	1,077	1,118
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Other Observable Inputs (Level 2) [Member] | U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	428	427
Fair Value, Measurements, Recurring [Member] | AARP Program [Member] | Other Observable Inputs (Level 2) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]	'	'
Available-for-sale Securities, Debt Securities	$139	$155

Fair_Value_Fair_Value_Inputs_A

Fair Value Fair Value Inputs Assets Quantitative Information (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Venture Capital Funds [Member] | Market Approach Valuation Technique [Member] | Comparable Companies [Member]	'
Available-for-sale Securities	210
Venture Capital Funds [Member] | Market Approach Valuation Technique [Member] | Recent Transactions [Member]	'
Available-for-sale Securities	36
Minimum [Member] | Comparable Companies [Member]	'
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	7
Fair Value Inputs, Revenue Multiple	1
Maximum [Member] | Comparable Companies [Member]	'
Fair Value Inputs, Earnings before Interest, Taxes, Depreciation, and Amortization Multiple	10
Fair Value Inputs, Revenue Multiple	10
Unobservable Inputs (Level 3) [Member] | Equity Securities [Member]	'
Available-for-sale Securities	246

Medicare_Part_D_Pharmacy_Benef2

Medicare Part D Pharmacy Benefits Medicare Part D Pharmacy Benefits (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Other current receivables	$3,772	$2,889
Other policy liabilities	5,484	4,910
CMS Subsidies [Member]	'	'
Other current receivables	638	461
Other policy liabilities	0	0
Drug Discount [Member]	'	'
Other current receivables	523	314
Other policy liabilities	380	319
Risk-Share [Member]	'	'
Other current receivables	0	0
Other policy liabilities	$469	$438

Medical_Cost_Devleopment_Detai

Medical Cost Devleopment (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Prior Fiscal Year [Member]	'	'	'	'
Favorable medical cost development	$180	$170	$580	$790
Related to Current Year [Member]	'	'	'	'
Favorable medical cost development	$110	$220	'	'

Commercial_Paper_and_LongTerm_2

Commercial Paper and Long-Term Debt (Narrative) (Details) (USD $)	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2013
In Millions, unless otherwise specified	Commercial Paper [Member]	Five Year $3.0 Billion Credit Facility [Member]	Five Year $3.0 Billion Credit Facility [Member]	Five Year $3.0 Billion Credit Facility [Member]	364 Day $1.0 Billion Credit Facility [Member]	364 Day $1.0 Billion Credit Facility [Member]	364 Day $1.0 Billion Credit Facility [Member]	364 Day $1.0 Billion Credit Facility [Member]
		Revolving Credit Facility [Member]	Minimum [Member]	Maximum [Member]	Revolving Credit Facility [Member]	Revolving Credit Facility [Member]	Minimum [Member]	Maximum [Member]
			Revolving Credit Facility [Member]	Revolving Credit Facility [Member]	banks		Revolving Credit Facility [Member]	Revolving Credit Facility [Member]
Five-year revolving bank credit facility, Amount Outstanding	'	$0	'	'	'	$0	'	'
Short-term Debt, Weighted Average Interest Rate	0.20%	'	'	'	'	'	'	'
Line of Credit, Credit Facility, Maximum Borrowing Capacity	$4,000	$3,000	'	'	$1,000	'	'	'
Debt Instrument, Interest Rate During Period	'	'	1.00%	1.20%	'	'	1.00%	1.20%
Number Of Years Of Revolving Bank Credit	'	'5 years	'	'	'	'	'	'
Credit Facility, Number of Days	'	'	'	'	'364	'	'	'
Number of banks that comprise revolving bank credit facility (banks)	'	21	'	'	21	'	'	'
Maximum percentage of indebtedness to total net capital bank covenant	'	50.00%	'	'	50.00%	'	'	'

Commercial_Paper_and_LongTerm_3

Commercial Paper and Long-Term Debt (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified
Par Value	$16,897		$16,705
Carrying Value	16,783		16,754
Fair Value	17,664		18,621
Commercial Paper [Member]	'		'
Par Value	1,060		1,587
Commercial Paper	1,060		1,587
Debt Instrument, Fair Value Disclosure	1,060		1,587
4.875% Senior Unsecured Notes Due February 2013 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	4.88%		'
Par Value	0		534
Carrying Value	0		534
Fair Value	0		536
4.875% Senior Unsecured Notes Due April 2013 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	4.88%		'
Par Value	0		409
Carrying Value	0		411
Fair Value	0		413
4.750% Senior Unsecured Notes Due February 2014 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	4.75%		'
Par Value	172		172
Carrying Value	175		178
Fair Value	175		180
5.000% Senior Unsecured Notes Due August 2014 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	5.00%		'
Par Value	389		389
Carrying Value	401		411
Fair Value	405		414
Senior Unsecured Floating-rate Notes Due August 2014 [Member]	'		'
Par Value	250		0
Carrying Value	250		0
Fair Value	250		0
4.875% Senior Unsecured Notes Due March 2015 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	4.88%		'
Par Value	416	[1]	416	[1]
Carrying Value	435	[1]	444	[1]
Fair Value	440	[1]	453	[1]
0.850% Senior Unsecured Notes due October 2015 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	0.85%		'
Par Value	625	[1]	625	[1]
Carrying Value	624	[1]	623	[1]
Fair Value	627	[1]	627	[1]
5.375% Senior Unsecured Notes Due March 2016 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	5.38%		'
Par Value	601	[1]	601	[1]
Carrying Value	645	[1]	660	[1]
Fair Value	663	[1]	682	[1]
1.875% of Senior Unsecured Notes Due November 2016 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	1.88%		'
Par Value	400		400
Carrying Value	398		397
Fair Value	409		412
5.360% Senior Unsecured Notes Due November 2016 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	5.36%		'
Par Value	95		95
Carrying Value	95		95
Fair Value	108		110
6.000% Senior Unsecured Notes Due June 2017 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	6.00%		'
Par Value	441		441
Carrying Value	481		489
Fair Value	509		528
1.400% Senior Unsecured Notes due October 2017 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	1.40%		'
Par Value	625	[1]	625	[1]
Carrying Value	614	[1]	622	[1]
Fair Value	617	[1]	626	[1]
6.000% Senior Unsecured Notes Due November 2017 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	6.00%		'
Par Value	156		156
Carrying Value	168		170
Fair Value	178		191
6.000% Senior Unsecured Notes Due February 2018 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	6.00%		'
Par Value	1,100		1,100
Carrying Value	1,117		1,120
Fair Value	1,282		1,339
1.625% Senior Unsecured Notes Due March 2019 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	1.63%		'
Par Value	500		0
Carrying Value	498		0
Fair Value	482		0
3.875% Senior Unsecured Notes Due October 2020 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	3.88%		'
Par Value	450		450
Carrying Value	443		442
Fair Value	474		499
4.700% Senior Unsecured Notes Due February 2021 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	4.70%		'
Par Value	400		400
Carrying Value	416		417
Fair Value	437		466
3.375% of Senior Unsecured Notes Due November 2021 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	3.38%		'
Par Value	500	[1]	500	[1]
Carrying Value	481	[1]	512	[1]
Fair Value	499	[1]	533	[1]
2.875% of Senior Unsecured Notes Due March 2022 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	2.88%		'
Par Value	1,100		1,100
Carrying Value	1,005		998
Fair Value	1,045		1,128
Zero Coupon Senior Unsecured Notes Due November 2022 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	0.00%		'
Par Value	15		15
Carrying Value	9		9
Fair Value	10		11
2.750% Senior Unsecured Notes due February 2023 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	2.75%		'
Par Value	625	[1]	625	[1]
Carrying Value	576	[1]	619	[1]
Fair Value	582	[1]	631	[1]
2.875% Senior Unsecured Notes due March 2023 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	2.88%		'
Par Value	750		0
Carrying Value	747		0
Fair Value	706		0
5.800% Senior Unsecured Notes Due March 2036 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	5.80%		'
Par Value	850		850
Carrying Value	845		845
Fair Value	940		1,025
6.500% Senior Unsecured Notes Due June 2037 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	6.50%		'
Par Value	500		500
Carrying Value	495		495
Fair Value	604		659
6.625% Senior Unsecured Notes Due November 2037 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	6.63%		'
Par Value	650		650
Carrying Value	645		645
Fair Value	795		860
6.875% Senior Unsecured Notes Due February 2038 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	6.88%		'
Par Value	1,100		1,100
Carrying Value	1,084		1,084
Fair Value	1,381		1,510
5.700% Senior Unsecured Notes Due October 2040 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	5.70%		'
Par Value	300		300
Carrying Value	298		298
Fair Value	332		364
5.950% Senior Unsecured Notes Due February 2041 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	5.95%		'
Par Value	350		350
Carrying Value	348		348
Fair Value	401		440
4.625% of Senior Unsecured Notes Due November 2041 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	4.63%		'
Par Value	600		600
Carrying Value	593		593
Fair Value	572		641
4.375% of Senior Unsecured Notes Due March 2042 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	4.38%		'
Par Value	502		502
Carrying Value	486		486
Fair Value	462		521
3.950% Senior Unsecured Notes due October 2042 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	3.95%		'
Par Value	625		625
Carrying Value	611		611
Fair Value	536		622
4.250% Senior Unsecured Notes due March 2043 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	4.25%		'
Par Value	750		0
Carrying Value	740		0
Fair Value	683		0
Domestic Corporate Debt Securities [Member]	'		'
Par Value	16,897		16,117
Carrying Value	16,783		16,143
Fair Value	17,664		18,008
Foreign Corporate Debt Securities [Member]	'		'
Par Value	0		588
Carrying Value	0		611
Fair Value	0		613
CDI and 1.300% [Member] | CDI and 1.3% Subsidiary Floating debt due October 2013 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	1.30%		'
Par Value	0		147
Carrying Value	0		148
Fair Value	0		150
CDI and 1.450% [Member] | CDI and 1.45 % Subsidiary floating debt due October 2014 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	1.45%		'
Par Value	0		147
Carrying Value	0		149
Fair Value	0		150
110% CDI [Member] | 110% CDI Subsidiary floating debt due December 2014 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	110.00%		'
Par Value	0		147
Carrying Value	0		151
Fair Value	0		147
CDI and 1.600% [Member] | CDI and 1.6% Subsidiary floating debt due October 2015 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	1.60%		'
Par Value	0		74
Carrying Value	0		76
Fair Value	0		76
Base Rate | IPCA and 7.61% Subsidiary floating debt due October 2015 [Member]	'		'
Debt Instrument, Interest Rate, Stated Percentage	7.61%		'
Par Value	0		73
Carrying Value	0		87
Fair Value	$0		$90
[1]	(a)Fixed-rate debt instruments hedged with interest rate swap contracts. See below for more information on the Company’s interest rate swaps.

Commercial_Paper_and_LongTerm_4

Commercial Paper and Long-Term Debt Balance Sheet Location of Fair Value Derivatives (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]	'	'
Interest Rate Derivative Liabilities, at Fair Value	$79,000,000	'
Interest rate swap assets	'	14,000,000
Interest Rate Swap [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative, Notional Amount	3,400,000,000	2,800,000,000
Interest Rate Swap [Member] | Other Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Interest Rate Derivative Liabilities, at Fair Value	79,000,000	11,000,000
Interest Rate Swap [Member] | Other Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Interest rate swap assets	'	$14,000,000

Commercial_Paper_and_LongTerm_5

Commercial Paper and Long-Term Debt Income Statement Recognition of Fair Value Hedge (Details) (Interest Expense [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Net impact on the Company’s Condensed Consolidated Statements of Operations	$0	$0	$0	$0
Interest Rate Swap [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Gain recognized in interest expense	9	5	'	17
Loss recognized in interest expense	'	'	-82	'
Debt [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Gain recognized in interest expense	'	'	82	'
Loss recognized in interest expense	($9)	($5)	'	($17)

Shareholders_Equity_Shareholde2

Shareholders' Equity Shareholder's Equity (Details) (USD $)	0 Months Ended			9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 24, 2013	Jun. 26, 2013	Mar. 26, 2013	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Common Stock, Dividends, Per Share, Cash Paid	$0.28	$0.28	$0.21	'	'	'	'
Payments of Dividends	$280	$281	$216	'	'	'	'
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	'	'	'	110	'	'	'
Stock Repurchased During Period, Shares	'	'	'	37	'	'	'
Treasury Stock Acquired, Average Cost Per Share	'	'	'	$63.87	'	'	'
Common stock repurchases	'	'	'	($2,348)	($2,594)	'	'
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	'	'	'	95	'	'	'
Cash Dividend Annual Rate Per Share	'	'	'	'	'	$1.12	$0.85

ShareBased_Compensation_Narrat

Share-Based Compensation (Narrative) (Details)	Sep. 30, 2013
In Millions, unless otherwise specified
Restricted Stock Units (RSUs) [Member]	'
Shares available for future grants	15
Total Shares Available To Grant [Member]	'
Shares available for future grants	35

ShareBased_Compensation_Stock_

Share-Based Compensation (Stock Option and SAR Activity) (Details) (USD $)	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]	'
Outstanding at the beginning of the period	63
Granted, Shares	8
Exercised, Shares	-25
Forfeited, Shares	-2
Outstanding at the end of the period	44
Exercisable at end of period, Shares	33
Vested and expected to vest end of period, Shares	43
Outstanding at beginning of period, Weighted-Average Exercise Price	$45
Granted, Weighted-Average Exercise Price	$58
Exercised, Weighted-Average Exercise Price	$43
Forfeited, Weighted-Average Exercise Price	$55
Outstanding at end of period, Weighted-Average Exercise Price	$48
Exercisable at end of period, Weighted-Average Exercise Price	$46
Vested and expected to vest end of period, Weighted-Average Exercise Price	$48
Outstanding at end of period, Weighted Average Remaining Contractual Term (in years)	'4 years 7 months 6 days
Exercisable at end of period, Weighted Average Remaining Contractual Term (in years)	'3 years 2 months 12 days
Vested and expected to vest end of period, Weighted Average Remaining Contractual Term (in years)	'4 years 7 months 6 days
Outstanding at end of period, Aggregate Intrinsic Value	$1,054
Exercisable at end of period, Aggregate Intrinsic Value	840
Vested and expected to vest end of period, Aggregate Intrinsic Value	$1,043

ShareBased_Compensation_Restri

Share-Based Compensation (Restricted Share Activity) (Details) (Restricted Stock [Member], USD $)	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013
Restricted Stock [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]	'
Nonvested at beginning of period, Shares	9
Granted, Shares	3
Forfeited, Shares	-1
Nonvested at end of period, Shares	11
Nonvested at beginning of period, Weighted-Average Grant Date Fair Value per Share	$46
Weighted-average grant date fair value of shares granted, per share	$58
Forfeitures, Weighted Average Grant Date Fair Value	$50
Nonvested at end of period, Weighted-Average Grant Date Fair Value per Share	$50

ShareBased_Compensation_Other_

Share-Based Compensation Other Share-Based Compensation Data (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other Share-Based Compensation Data [Line Items]	'	'	'	'
Share-based compensation expense, before tax	$79	$87	$255	$329
Share-based compensation expense, net of tax effects	67	70	174	230
Income tax benefit realized from share-based award exercises	62	14	178	288
Unrecognized compensation expense related to share awards	374	'	374	'
Weighted-average years to recognize compensation expense	'	'	'1 year 3 months 18 days	'
Stock Options and SARs [Member]	'	'	'	'
Other Share-Based Compensation Data [Line Items]	'	'	'	'
Weighted-average grant date fair value of shares granted, per share	$23	$16	$19	$18
Total intrinsic value of stock options and SARs exercised	182	44	507	442
Restricted Stock Units (RSUs) [Member]	'	'	'	'
Other Share-Based Compensation Data [Line Items]	'	'	'	'
Weighted-average grant date fair value (per share)	$72	$51	$58	$52
Total fair value of restricted shares vested	$0	$5	$0	$357

ShareBased_Compensation_ShareB

Share-Based Compensation (Share-Based Compensation Principal Fair Value Assumptions) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Risk free interest rate minimum	1.60%	0.70%	'	'
Expected volatility minimum	41.80%	44.00%	'	'
Expected dividend yield	1.50%	1.70%	'	'
Forfeiture rate	5.00%	5.00%	5.00%	5.00%
Expected Life in years	'5 years 3 months 18 days	'5 years 3 months 18 days	'5 years 3 months 18 days	'
Minimum [Member]	'	'	'	'
Risk free interest rate minimum	'	'	1.00%	0.70%
Expected volatility minimum	'	'	41.80%	43.40%
Expected dividend yield	'	'	1.40%	1.20%
Expected Life in years	'	'	'	'5 years 3 months 18 days
Maximum [Member]	'	'	'	'
Risk free interest rate maximum	'	'	1.60%	0.90%
Expected volatility maximum	'	'	43.00%	44.00%
Expected dividend yield	'	'	1.50%	1.70%
Expected Life in years	'	'	'	'5 years 7 months 6 days

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	1 Months Ended			9 Months Ended		1 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
	California Claims Processing Matter [Member]	Endoscopy Center of Southern Nevada Litigation [Member]	Endoscopy Center of Southern Nevada Litigation [Member]	Endoscopy Center of Southern Nevada Litigation [Member]	Endoscopy Center of Southern Nevada Litigation [Member]	Endoscopy Center of Southern Nevada Litigation [Member]
		class_action_lawsuit	individual_lawsuit	Compensatory Damages [Member]	Punitive Damages [Member]	Post-Trial Motions [Member]
Estimated Largest Aggregate Penalty Issued By Cdi	$8	'	'	'	'	'
CDI aggregate penalty	325	'	'	'	'	'
Loss Contingency, Damages Awarded, Value	'	'	'	$24	$500	$366
Individual Lawsuits [Line Items]	'	2	41	'	'	'

Segment_Financial_Information_1

Segment Financial Information Segment Financial Information (Narrative) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Number of Reportable Segments	4	'
Payments to Acquire Interest in Subsidiaries and Affiliates	$1,474	$0
Step Four [Member] | Amil Participacoes S.A. [Member]	'	'
Payments to Acquire Interest in Subsidiaries and Affiliates	$1,474	'
Business Acquisition, Percentage of Voting Interests Acquired	90.00%	'
Remaining Publically Traded Shares [Member] | Step Four [Member] | Amil Participacoes S.A. [Member]	'	'
Business Acquisition, Percentage of Voting Interests Acquired	100.00%	'

Segment_Financial_Information_2

Segment Financial Information (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Premiums, revenues - external customers	$27,356	$24,640	$81,850	$73,880
Services, revenues - external customers	2,280	1,824	6,636	5,415
Products, revenues - external customers	825	693	2,325	2,059
Revenues	30,624	27,302	91,372	81,849
Investment and other income	163	145	561	495
Earnings from operations	2,631	2,610	7,171	7,153
Interest expense	-178	-158	-532	-459
Earnings before income taxes	2,453	2,452	6,639	6,694
UnitedHealthcare [Member]	'	'	'	'
Premiums, revenues - external customers	26,698	24,197	79,982	72,592
Services, revenues - external customers	1,579	1,196	4,566	3,558
Products, revenues - external customers	2	0	6	0
Investment and other income	130	119	466	411
Earnings from operations	2,003	2,202	5,512	6,173
Interest expense	0	0	0	0
Earnings before income taxes	2,003	2,202	5,512	6,173
Total Optum [Member]	'	'	'	'
Premiums, revenues - external customers	658	443	1,868	1,288
Services, revenues - external customers	701	628	2,070	1,857
Products, revenues - external customers	823	693	2,319	2,059
Investment and other income	33	26	95	84
Earnings from operations	628	408	1,659	980
Interest expense	0	0	0	0
Earnings before income taxes	628	408	1,659	980
OptumHealth [Member]	'	'	'	'
Premiums, revenues - external customers	658	443	1,868	1,288
Services, revenues - external customers	193	176	576	565
Products, revenues - external customers	4	4	14	17
Investment and other income	32	26	94	84
Earnings from operations	280	168	731	383
Interest expense	0	0	0	0
Earnings before income taxes	280	168	731	383
OptumInsight [Member]	'	'	'	'
Premiums, revenues - external customers	0	0	0	0
Services, revenues - external customers	484	431	1,423	1,231
Products, revenues - external customers	22	21	55	48
Investment and other income	1	0	1	0
Earnings from operations	144	126	450	310
Interest expense	0	0	0	0
Earnings before income taxes	144	126	450	310
OptumRx [Member]	'	'	'	'
Premiums, revenues - external customers	0	0	0	0
Services, revenues - external customers	24	21	71	61
Products, revenues - external customers	797	668	2,250	1,994
Investment and other income	0	0	0	0
Earnings from operations	204	114	478	287
Interest expense	0	0	0	0
Earnings before income taxes	204	114	478	287
Corporate and Intersegment Eliminations [Member]	'	'	'	'
Premiums, revenues - external customers	0	0	0	0
Services, revenues - external customers	0	0	0	0
Products, revenues - external customers	0	0	0	0
Investment and other income	0	0	0	0
Earnings from operations	0	0	0	0
Interest expense	-178	-158	-532	-459
Earnings before income taxes	-178	-158	-532	-459
External Customers [Member]	'	'	'	'
Revenues	30,461	27,157	90,811	81,354
External Customers [Member] | UnitedHealthcare [Member]	'	'	'	'
Revenues	28,279	25,393	84,554	76,150
External Customers [Member] | Total Optum [Member]	'	'	'	'
Revenues	2,182	1,764	6,257	5,204
External Customers [Member] | OptumHealth [Member]	'	'	'	'
Revenues	855	623	2,458	1,870
External Customers [Member] | OptumInsight [Member]	'	'	'	'
Revenues	506	452	1,478	1,279
External Customers [Member] | OptumRx [Member]	'	'	'	'
Revenues	821	689	2,321	2,055
External Customers [Member] | Corporate and Intersegment Eliminations [Member]	'	'	'	'
Revenues	0	0	0	0
Intersegment [Member]	'	'	'	'
Revenues	0	0	0	0
Intersegment [Member] | UnitedHealthcare [Member]	'	'	'	'
Revenues	0	0	0	0
Intersegment [Member] | Total Optum [Member]	'	'	'	'
Revenues	7,372	5,436	20,485	16,570
Intersegment [Member] | OptumHealth [Member]	'	'	'	'
Revenues	1,607	1,405	4,795	4,064
Intersegment [Member] | OptumInsight [Member]	'	'	'	'
Revenues	291	266	873	781
Intersegment [Member] | OptumRx [Member]	'	'	'	'
Revenues	5,474	3,765	14,817	11,725
Intersegment [Member] | Corporate and Intersegment Eliminations [Member]	'	'	'	'
Revenues	-7,372	-5,436	-20,485	-16,570
Total Revenues [Member]	'	'	'	'
Revenues	30,624	27,302	91,372	81,849
Total Revenues [Member] | UnitedHealthcare [Member]	'	'	'	'
Revenues	28,409	25,512	85,020	76,561
Total Revenues [Member] | Total Optum [Member]	'	'	'	'
Revenues	9,587	7,226	26,837	21,858
Total Revenues [Member] | OptumHealth [Member]	'	'	'	'
Revenues	2,494	2,054	7,347	6,018
Total Revenues [Member] | OptumInsight [Member]	'	'	'	'
Revenues	798	718	2,352	2,060
Total Revenues [Member] | OptumRx [Member]	'	'	'	'
Revenues	6,295	4,454	17,138	13,780
Total Revenues [Member] | Corporate and Intersegment Eliminations [Member]	'	'	'	'
Revenues	($7,372)	($5,436)	($20,485)	($16,570)