UnitedHealth (UNH) 10-K 1 Mar 21 2020 FY Annual report Financial data

Cover Document

Cover Document - USD ($)	12 Months Ended
	Dec. 31, 2020	Jan. 29, 2021	Jun. 30, 2020
Cover Page [Abstract]
Entity File Number	1-10864
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Transition Report	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	41-1321939
Entity Address, Address Line One	UnitedHealth Group Center
Entity Address, Address Line Two	9900 Bren Road East
Entity Address, City or Town	Minnetonka,
Entity Address, State or Province	MN
Entity Address, Postal Zip Code	55343
City Area Code	952
Local Phone Number	936-1300
Title of 12(b) Security	Common Stock, $.01 par value
Trading Symbol	UNH
Security Exchange Name	NYSE
Well known seasoned issuer	Yes
Entity Voluntary Filers	No
Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Public Float			$ 281,771,756,077
Entity Common Stock, Shares Outstanding		945,319,404
Documents Incorporated by Reference	The information required by Part III of this report, to the extent not set forth herein, is incorporated by reference from the registrant’s definitive proxy statement relating to its 2021 Annual Meeting of Shareholders. Such proxy statement will be filed with the Securities and Exchange Commission within 120 days after the end of the fiscal year to which this report relates.
Entity Registrant Name	UnitedHealth Group Incorporated
Entitiy Central Index Key	0000731766
ICFR Auditor Attestation Flag	true

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) shares in Millions, $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 16,921	$ 10,985
Short-term investments	2,860	3,260
Accounts receivable, net of allowances of $990 and $519	12,870	11,822
Other current receivables, net of allowances of $1,047 and $859	12,534	9,640
Assets under management	4,076	3,076
Prepaid expenses and other current assets	4,457	3,851
Total current assets	53,718	42,634
Long-term investments	41,242	37,209
Property, equipment and capitalized software, net of accumulated depreciation and amortization of $5,230 and $4,995	8,626	8,704
Goodwill	71,337	65,659
Other intangible assets, net of accumulated amortization of $5,455 and $5,072	10,856	10,349
Other assets	11,510	9,334
Total assets	197,289	173,889
Current liabilities:
Medical costs payable	21,872	21,690
Accounts payable and accrued liabilities	22,495	19,005
Short-term borrowings and current maturities of long-term debt	4,819	3,870
Unearned revenues	2,842	2,622
Other current liabilities	20,392	14,595
Total current liabilities	72,420	61,782
Long-term debt, less current maturities	38,648	36,808
Deferred Income Taxes	3,367	2,993
Other liabilities	12,315	10,144
Total liabilities	126,750	111,727
Commitments and contingencies (Note 12)
Redeemable noncontrolling interests	2,211	1,726
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; 946 and 948 issued and outstanding	10	9
Additional paid-in capital	0	7
Retained earnings	69,295	61,178
Accumulated other comprehensive loss	(3,814)	(3,578)
Nonredeemable noncontrolling interests	2,837	2,820
Total equity	68,328	60,436
Total liabilities, redeemable noncontrolling interests and equity	$ 197,289	$ 173,889
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10	10
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	3,000	3,000
Common stock, shares issued	946	948
Common Stock, Shares, Outstanding	946	948

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts, accounts receivable	$ 990	$ 519
Allowance for doubtful accounts, other receivables	1,047	859
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	5,230	4,995
Finite-lived Intangible Assets, Accumulated Amortization	$ 5,455	$ 5,072
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	3,000	3,000
Common stock, shares issued	946	948
Common Stock, shares outstanding	946	948
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10	10
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Premiums	$ 201,478	$ 189,699	$ 178,087
Products	34,145	31,597	29,601
Services	20,016	18,973	17,183
Investment and other income	1,502	1,886	1,376
Total revenues	257,141	242,155	226,247
Operating costs:
Medical costs	159,396	156,440	145,403
Operating costs	41,704	35,193	34,074
Cost of products sold	30,745	28,117	26,998
Depreciation and amortization	2,891	2,720	2,428
Total operating costs	234,736	222,470	208,903
Earnings from operations	22,405	19,685	17,344
Interest expense	(1,663)	(1,704)	(1,400)
Earnings before income taxes	20,742	17,981	15,944
Provision for income taxes	(4,973)	(3,742)	(3,562)
Net earnings	15,769	14,239	12,382
Earnings attributable to noncontrolling interests	(366)	(400)	(396)
Net earnings attributable to UnitedHealth Group common shareholders	$ 15,403	$ 13,839	$ 11,986
Earnings per share attributable to UnitedHealth Group common shareholders:
Basic	$ 16.23	$ 14.55	$ 12.45
Diluted	$ 16.03	$ 14.33	$ 12.19
Basic weighted-average number of common shares outstanding	949	951	963
Dilutive effect of common share equivalents	12	15	20
Diluted weighted-average number of common shares outstanding	961	966	983
Anti-dilutive shares excluded from the calculation of dilutive effect of common share equivalents	8	10	6

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net earnings	$ 15,769	$ 14,239	$ 12,382
Other comprehensive (loss) income:
Gross unrealized gains (losses) on investment securities during the period	1,058	1,212	(294)
Income tax effect	(253)	(279)	67
Total unrealized gains (losses), net of tax	805	933	(227)
Gross reclassification adjustment for net realized gains included in net earnings	(75)	(104)	(62)
Income tax effect	17	24	14
Total reclassification adjustment, net of tax	(58)	(80)	(48)
Total foreign currency translation losses	(983)	(271)	(1,242)
Other comprehensive (loss) income	(236)	582	(1,517)
Comprehensive income	15,533	14,821	10,865
Comprehensive income attributable to noncontrolling interests	(366)	(400)	(396)
Comprehensive income attributable to UnitedHealth Group common shareholders	$ 15,167	$ 14,421	$ 10,469

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Net Unrealized (Losses) Gains on Investments [Member]	Foreign Currency Translation Losses [Member]	Noncontrolling Interest
Balance at Dec. 31, 2017	$ 49,833	$ 10	$ 1,703	$ 48,730	$ (13)	$ (2,654)	$ 2,057
Balance (Accounting Standards Update 2016-01) at Dec. 31, 2017	0			(24)	24
Balance (in shares) at Dec. 31, 2017		969
Net earnings attributable to UnitedHealth Group common shareholders	11,986			11,986
Net earnings attributable to nonredeemable noncontrolling interest							273
Net earnings, Including Portion Attributable to Nonredeemable Noncontrolling Interest	12,259
Other comprehensive income (loss)	(1,517)				(275)	(1,242)
Issuances of common stock, and related tax effects (in shares)		10
Issuances of common stock, and related tax effects	814	$ 0	814
Share-based compensation	620		620
Common share repurchases (in shares)		(19)
Common share repurchases	(4,500)	$ 0	(2,974)	(1,526)
Cash dividends paid on common shares ($4.83 per share, $4.14 per share and $3.45 per share for the years ended December 31, 2020, 2019 and 2018, respectively)	(3,320)			(3,320)
Redeemable noncontrolling interests fair value and other adjustments	(163)		(163)
Acquisition and other adjustments of nonredeemable noncontrolling interests	521						521
Distributions to nonredeemable noncontrolling interests	(228)						(228)
Balance at Dec. 31, 2018	54,319	$ 10	0	55,846	(264)	(3,896)	2,623
Balance (Accounting Standards Update 2016-02 [Member]) at Dec. 31, 2018	(18)			(13)			(5)
Balance (in shares) at Dec. 31, 2018		960
Net earnings attributable to UnitedHealth Group common shareholders	13,839			13,839
Net earnings attributable to nonredeemable noncontrolling interest							285
Net earnings, Including Portion Attributable to Nonredeemable Noncontrolling Interest	14,124
Other comprehensive income (loss)	582				853	(271)
Issuances of common stock, and related tax effects (in shares)		10
Issuances of common stock, and related tax effects	696	$ 0	696
Share-based compensation	$ 673		673
Common share repurchases (in shares)	(22)	(22)
Common share repurchases	$ (5,500)	$ (1)	(937)	(4,562)
Cash dividends paid on common shares ($4.83 per share, $4.14 per share and $3.45 per share for the years ended December 31, 2020, 2019 and 2018, respectively)	(3,932)			(3,932)
Redeemable noncontrolling interests fair value and other adjustments	(316)		(316)
Acquisition and other adjustments of nonredeemable noncontrolling interests	87		(109)				196
Distributions to nonredeemable noncontrolling interests	(279)						(279)
Balance at Dec. 31, 2019	60,436	$ 9	7	61,178	589	(4,167)	2,820
Balance (Accounting Standards Update 2016-13) at Dec. 31, 2019	$ (28)			(28)
Balance (in shares) at Dec. 31, 2019	948	948
Net earnings attributable to UnitedHealth Group common shareholders	$ 15,403			15,403
Net earnings attributable to nonredeemable noncontrolling interest							254
Net earnings, Including Portion Attributable to Nonredeemable Noncontrolling Interest	15,657
Other comprehensive income (loss)	(236)				747	(983)
Issuances of common stock, and related tax effects (in shares)		12
Issuances of common stock, and related tax effects	1,120	$ 1	1,119
Share-based compensation	$ 647		647
Common share repurchases (in shares)	(14)	(14)
Common share repurchases	$ (4,250)	$ 0	(1,576)	(2,674)
Cash dividends paid on common shares ($4.83 per share, $4.14 per share and $3.45 per share for the years ended December 31, 2020, 2019 and 2018, respectively)	(4,584)			(4,584)
Redeemable noncontrolling interests fair value and other adjustments	(197)		(197)
Acquisition and other adjustments of nonredeemable noncontrolling interests	40						40
Distributions to nonredeemable noncontrolling interests	(277)						(277)
Balance at Dec. 31, 2020	$ 68,328	$ 10	$ 0	$ 69,295	$ 1,336	$ (5,150)	$ 2,837
Balance (in shares) at Dec. 31, 2020	946	946

Consolidated Statement of Chang

Consolidated Statement of Changes in Equity (Parentheticals) - $ / shares	Dec. 15, 2020	Sep. 22, 2020	Jun. 30, 2020	Mar. 24, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Cash dividends per common share	$ 1.25	$ 1.25	$ 1.25	$ 1.08	$ 4.83	$ 4.14	$ 3.45

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Net earnings	$ 15,769	$ 14,239	$ 12,382
Noncash items:
Depreciation and amortization	2,891	2,720	2,428
Deferred income taxes	(8)	230	42
Share-based compensation	679	697	638
Other, net	(52)	(106)	(71)
Net change in other operating items, net of effects from acquisitions and changes in AARP balances:
Accounts receivable	(688)	162	(1,351)
Other assets	(2,195)	(1,563)	(750)
Medical costs payable	152	1,221	1,831
Accounts payable and other liabilities	5,348	733	526
Unearned revenues	278	130	38
Cash flows from operating activities	22,174	18,463	15,713
Investing activities
Purchases of investments	(16,577)	(18,131)	(14,010)
Sales of investments	6,489	8,536	3,641
Maturities of investments	7,252	7,091	6,270
Cash paid for acquisitions, net of cash assumed	(7,139)	(8,343)	(5,997)
Purchases of property, equipment and capitalized software	(2,051)	(2,071)	(2,063)
Other, net	(506)	219	(226)
Cash flows used for investing activities	(12,532)	(12,699)	(12,385)
Financing activities
Common share repurchases	(4,250)	(5,500)	(4,500)
Cash dividends paid	(4,584)	(3,932)	(3,320)
Proceeds from common stock issuances	1,440	1,037	838
Repayments of long-term debt	(3,150)	(1,750)	(2,600)
Proceeds from (repayments of) short-term borrowings, net	872	300	(201)
Proceeds from issuance of long-term debt	4,864	5,444	6,935
Customer funds administered	1,677	13	(131)
Other, net	(459)	(1,237)	(1,386)
Cash flows used for financing activities	(3,590)	(5,625)	(4,365)
Effect of exchange rate changes on cash and cash equivalents	(116)	(20)	(78)
Increase (decrease) in cash and cash equivalents	5,936	119	(1,115)
Cash and cash equivalents, beginning of period	10,985	10,866	11,981
Cash and cash equivalents, end of period	16,921	10,985	10,866
Supplemental cash flow disclosures
Cash paid for interest	1,704	1,627	1,410
Cash paid for income taxes	$ 4,935	$ 3,542	$ 3,257

Description of Business (Notes)

Description of Business (Notes)	12 Months Ended
	Dec. 31, 2020
Nature of Operations [Text Block]	Description of BusinessUnitedHealth Group Incorporated (individually and together with its subsidiaries, “UnitedHealth Group” and “the Company”) is a diversified health care company with a mission to help people live healthier lives and help make the health system work better for everyone. Our two complementary businesses — Optum and UnitedHealthcare — are driven by this unified mission and vision to improve health care access, affordability, experiences and outcomes for the individuals and organizations we are privileged to serve.

Basis of Presentation, Uses of

Basis of Presentation, Uses of Estimates and Significant Accounting Policies (Notes)	12 Months Ended
	Dec. 31, 2020
Basis of Presentation and Significant Accounting Policies [Text Block]	Basis of Presentation, Use of Estimates and Significant Accounting Policies Basis of Presentation The Company has prepared the Consolidated Financial Statements according to U.S. Generally Accepted Accounting Principles (GAAP) and has included the accounts of UnitedHealth Group and its subsidiaries. Use of Estimates These Consolidated Financial Statements include certain amounts based on the Company’s best estimates and judgments. The Company’s most significant estimates relate to estimates and judgments for medical costs payable and goodwill. Certain of these estimates require the application of complex assumptions and judgments, often because they involve matters inherently uncertain and will likely change in subsequent periods. The impact of any change in estimates is included in earnings in the period in which the estimate is adjusted. Revenues Premiums Premium revenues are primarily derived from risk-based health insurance arrangements in which the premium is typically at a fixed rate per individual served for a one-year period, and the Company assumes the economic risk of funding its customers’ health care and related administrative costs. Premium revenues are recognized in the period in which eligible individuals are entitled to receive health care benefits. Health care premium payments received from the Company’s customers in advance of the service period are recorded as unearned revenues. Fully insured commercial products of U.S. health plans, Medicare Advantage and Medicare Prescription Drug Benefit (Medicare Part D) plans with medical loss ratios (MLRs) as calculated under the definitions in the Patient Protection and Affordable Care Act (ACA) and related federal and state regulations and implementing regulation, falling below certain targets are required to rebate ratable portions of their premiums annually. Commercial premiums within the Company’s individual and small group markets are also subject to the ACA risk adjustment program. Medicare Advantage premium revenue includes the impact of the Centers for Medicare & Medicaid Services (CMS) quality bonuses based on plans’ Star rating. Certain of the Company’s Medicaid business is also subject to state minimum MLR rebates. Premium revenues are recognized based on the estimated premiums earned, net of projected rebates, because the Company is able to reasonably estimate the ultimate premiums of these contracts. The Company also records premium revenues for certain risk-based arrangements at its OptumHealth care delivery businesses. The Company’s Medicare Advantage and Medicare Part D premium revenues are subject to periodic adjustment under CMS’ risk adjustment payment methodology. CMS deploys a risk adjustment model which apportions premiums paid to all health plans according to health severity and certain demographic factors. The CMS risk adjustment model provides higher per member payments for enrollees diagnosed with certain conditions and lower payments for enrollees who are healthier. Under this risk adjustment methodology, CMS calculates the risk adjusted premium payment using diagnosis and encounter data from hospital inpatient, hospital outpatient and physician treatment settings. The Company and health care providers collect, capture and submit the necessary and available data to CMS within prescribed deadlines. The Company estimates risk adjustment premium revenues based upon the data submitted and expected to be submitted to CMS. Risk adjustment data for the Company’s plans are subject to review by the government, including audit by regulators. See Note 12 for additional information regarding these audits. Products and Services For the Company’s OptumRx pharmacy care services business, the majority of revenues are derived from products sold through a contracted network of retail pharmacies or home delivery, specialty and community health pharmacies. Product revenues include the cost of pharmaceuticals (net of rebates), a negotiated dispensing fee and customer co-payments for drugs dispensed through the Company’s home delivery, specialty and community pharmacies. For the year ended December 31, 2020, the Company recognized revenue and cost of products sold for retail pharmacy co-payments related to its OptumRx business. Revenue recognized in prior periods related to retail pharmacy transactions excludes the member’s applicable co-payment. There was no impact on earnings from operations, net earnings, earnings per share or total equity. Pharmacy products are billed to customers based on the number of transactions occurring during the billing period. Product revenues are recognized when the prescriptions are dispensed. The Company has entered into contracts in which it is primarily obligated to pay its network pharmacy providers for benefits provided to their customers regardless of whether the Company is paid. The Company is also involved in establishing the prices charged by retail pharmacies, determining which drugs will be included in formulary listings and selecting which retail pharmacies will be included in the network offered to plan sponsors’ members and accordingly, are reported on a gross basis. Services revenue consists of fees derived from services performed for customers who self-insure the health care costs of their employees and employees’ dependents. Under service fee contracts, the Company receives monthly, a fixed fee per employee, which is recognized as revenue as the Company performs, or makes available, the applicable services to the customer. The customers retain the risk of financing health care costs for their employees and employees’ dependents, and the Company administers the payment of customer funds to physicians and other health care professionals from customer-funded bank accounts. As the Company has neither the obligation for funding the health care costs, nor the primary responsibility for providing the medical care, the Company does not recognize premium revenue and medical costs for these contracts in its Consolidated Financial Statements. For these fee-based customer arrangements, the Company provides coordination and facilitation of medical services; transaction processing; customer, consumer and care professional services; and access to contracted networks of physicians, hospitals and other health care professionals. These services are performed throughout the contract period. Revenues are also comprised of a number of services and products sold through Optum. OptumHealth’s service revenues include net patient service revenues recorded based upon established billing rates, less allowances for contractual adjustments, and are recognized as services are provided. For its financial services offerings, OptumHealth charges fees and earns investment income on managed funds. OptumInsight provides software and information products, advisory consulting arrangements and managed services outsourcing contracts, which may be delivered over several years. OptumInsight revenues are generally recognized over time and measured each period based on the progress to date as services are performed or made available to customers. As of December 31, 2020 and 2019, accounts receivables related to products and services were $5.3 billion and $4.3 billion, respectively. In 2020 and 2019, the Company had no material bad-debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the Consolidated Balance Sheets as of December 31, 2020 or 2019. For the years ended December 31, 2020 and 2019, revenue recognized from performance obligations related to prior periods (for example, due to changes in transaction price) was not material. Revenue expected to be recognized in any future year related to remaining performance obligations, excluding revenue pertaining to contracts having an original expected duration of one year or less, contracts where revenue is recognized as invoiced and contracts with variable consideration related to undelivered performance obligations, is not material. See Note 14 for disaggregation of revenue by segment and type. Medical Costs and Medical Costs Payable The Company’s estimate of medical costs payable represents management’s best estimate of its liability for unpaid medical costs as of December 31, 2020. Each period, the Company re-examines previously established medical costs payable estimates based on actual claim submissions and other changes in facts and circumstances. As more complete claim information becomes available, the Company adjusts the amount of the estimates and includes the changes in estimates in medical costs in the period in which the change is identified. Approximately 90% of claims related to medical care services are known and settled within 90 days from the date of service and substantially all within twelve months. Medical costs and medical costs payable include estimates of the Company’s obligations for medical care services rendered on behalf of insured consumers, but for which claims have either not yet been received, processed, or paid. The Company develops estimates for medical care services incurred but not reported (IBNR), which includes estimates for claims which have not been received or fully processed, using an actuarial process consistently applied, centrally controlled and automated. The actuarial models consider factors such as time from date of service to claim processing, seasonal variances in medical care consumption, health care professional contract rate changes, medical care utilization and other medical cost trends, membership volume and demographics, the introduction of new technologies, benefit plan changes, and business mix changes related to products, customers and geography. Judgments related to these factors contemplated the impact of COVID-19 in 2020. Cost of Products Sold The Company’s cost of products sold includes the cost of pharmaceuticals dispensed to unaffiliated customers either directly at its home delivery, specialty and community pharmacy locations, or indirectly through its nationwide network of participating pharmacies. Rebates attributable to non-affiliated clients are accrued as rebates receivable and a reduction of cost of products sold, with a corresponding payable for the amounts of the rebates to be remitted to those non-affiliated clients in accordance with their contracts and recorded in the Consolidated Statements of Operations as a reduction of product revenue. Cost of products sold also includes the cost of personnel to support the Company’s transaction processing services, system sales, maintenance and professional services. Cash, Cash Equivalents and Investments Cash and cash equivalents are highly liquid investments having an original maturity of three months or less. The fair value of cash and cash equivalents approximates their carrying value because of the short maturity of the instruments. Investments with maturities of less than one year are classified as short-term. Because of regulatory requirements, certain investments are included in long-term investments regardless of their maturity date. The Company classifies these investments as held-to-maturity and reports them at amortized cost. Substantially all other investments are classified as available-for-sale and reported at fair value based on quoted market prices, where available. Equity investments, with certain exceptions, are measured at fair value with changes in fair value recognized in net earnings. The Company excludes unrealized gains and losses on investments in available-for-sale debt securities from net earnings and reports them as comprehensive income and, net of income tax effects, as a separate component of equity. To calculate realized gains and losses on the sale of debt securities, the Company specifically identifies the cost of each investment sold. The Company evaluates an available-for-sale debt security for credit-related impairment by considering the present value of expected cash flows relative to a security’s amortized cost, the extent to which fair value is less than amortized cost, the financial condition and near-term prospects of the issuer and specific events or circumstances which may influence the operations of the issuer. Credit-related impairments are recorded as an allowance, with an offset to investment and other income. Non-credit related impairments are recorded through other comprehensive income. If the Company intends to sell an impaired security, or will likely be required to sell a security before recovery of the entire amortized cost, the entire impairment is included in net earnings. New information and the passage of time can change these judgments. The Company manages its investment portfolio to limit its exposure to any one issuer or market sector, and largely limits its investments to investment grade quality. Securities downgraded below policy minimums after purchase will be disposed of in accordance with the Company’s investment policy. Assets Under Management The Company provides health insurance products and services to members of AARP under a Supplemental Health Insurance Program (the AARP Program) and to AARP members and non-members under separate Medicare Advantage and Medicare Part D arrangements. The products and services under the AARP Program include supplemental Medicare benefits, hospital indemnity insurance, including insurance for individuals between 50 to 64 years of age, and other related products. Pursuant to the Company’s agreement with AARP, program assets are managed separately from the Company’s general investment portfolio and are used to pay costs associated with the AARP Program. These assets are invested at the Company’s discretion, within investment guidelines approved by AARP. The Company does not guarantee any rates of return on these investments and, upon any transfer of the AARP Program contract to another entity, the Company would transfer cash equal in amount to the fair value of these investments at the date of transfer to the entity. Because the purpose of these assets is to fund the medical costs payable, the rate stabilization fund (RSF) liabilities and other related liabilities associated with this AARP contract, assets under management are classified as current assets, consistent with the classification of these liabilities. The effects of changes in other balance sheet amounts associated with the AARP Program also accrue to the overall benefit of the AARP policyholders through the RSF balance. Accordingly, the Company excludes the effect of such changes in its Consolidated Statements of Cash Flows. Other Current Receivables Other current receivables include amounts due from pharmaceutical manufacturers for rebates and Medicare Part D drug discounts, accrued interest and other miscellaneous amounts due to the Company. The Company’s pharmacy care services businesses contract with pharmaceutical manufacturers, some of which provide rebates based on use of the manufacturers’ products by its affiliated and non-affiliated clients. The Company accrues rebates as they are earned by its clients on a monthly basis based on the terms of the applicable contracts, historical data and current estimates. The pharmacy care services businesses bill these rebates to the manufacturers on a monthly or quarterly basis depending on the contractual terms and record rebates attributable to affiliated clients as a reduction to medical costs. The Company generally receives rebates two to five months after billing. As of December 31, 2020 and 2019, total pharmaceutical manufacturer rebates receivable included in other receivables in the Consolidated Balance Sheets amounted to $6.3 billion and $4.7 billion, respectively. As of December 31, 2020 and 2019, the Company’s Medicare Part D receivables amounted to $2.9 billion and $2.3 billion, respectively. Property, Equipment and Capitalized Software Property, equipment and capitalized software are stated at cost, net of accumulated depreciation and amortization. Capitalized software consists of certain costs incurred in the development of internal-use software, including external direct costs of materials and services and applicable payroll costs of employees devoted to specific software development. The Company calculates depreciation and amortization using the straight-line method over the estimated useful lives of the assets. The useful lives for property, equipment and capitalized software are: Furniture, fixtures and equipment 3 to 10 years Buildings 35 to 40 years Capitalized software 3 to 5 years Leasehold improvements are depreciated over the shorter of the remaining lease term or their estimated useful economic life. Operating Leases The Company leases facilities and equipment under long-term operating leases which are non-cancelable and expire on various dates. At the lease commencement date, lease right-of-use (ROU) assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term, which includes all fixed obligations arising from the lease contract. If an interest rate is not implicit in a lease, the Company utilizes its incremental borrowing rate for a period closely matching the lease term. The Company’s ROU assets are included in other assets, and lease liabilities are included in other current liabilities and other liabilities in the Company’s Consolidated Balance Sheet. Goodwill To determine whether goodwill is impaired, annually or more frequently if needed, the Company performs impairment tests. The Company may first assess qualitative factors to determine if it is more likely than not the carrying value of a reporting unit exceeds its estimated fair value. The Company may also elect to skip the qualitative testing and proceed directly to the quantitative testing. When performing quantitative testing, the Company first estimates the fair values of its reporting units using discounted cash flows or a weighted combination of discounted cash flows and a market-based method. To determine fair values, the Company must make assumptions about a wide variety of internal and external factors. Significant assumptions used in the impairment analysis include financial projections of free cash flow (including significant assumptions about operations, capital requirements and income taxes), long-term growth rates for determining terminal value, discount rates and the selection of comparable peer companies. If the fair value is less than the carrying value of the reporting unit, an impairment is recognized for the difference, up to the carrying amount of goodwill. There was no impairment of goodwill during the year ended December 31, 2020. Intangible Assets The Company’s intangible assets are subject to impairment tests when events or circumstances indicate an intangible asset (or asset group) may be impaired. The Company’s indefinite-lived intangible assets are also tested for impairment annually. There was no impairment of intangible assets during the year ended December 31, 2020. Other Current Liabilities Other current liabilities include health savings account deposits ($10.2 billion and $8.3 billion as of December 31, 2020 and 2019, respectively), the RSF associated with the AARP Program, accruals for premium rebates payable, the current portion of future policy benefits and customer balances. Policy Acquisition Costs The Company’s short duration health insurance contracts typically have a one-year term and may be canceled by the customer with at least 30 days’ notice. Costs related to the acquisition and renewal of short duration customer contracts are primarily charged to expense as incurred. Redeemable Noncontrolling Interests Redeemable noncontrolling interests in the Company’s subsidiaries whose redemption is outside the control of the Company are classified as temporary equity. The following table provides details of the Company's redeemable noncontrolling interests’ activity for the years ended December 31, 2020 and 2019: (in millions) 2020 2019 Redeemable noncontrolling interests, beginning of period $ 1,726 $ 1,908 Net earnings 112 115 Acquisitions 321 90 Redemptions — (618) Distributions (149) (69) Fair value and other adjustments 201 300 Redeemable noncontrolling interests, end of period $ 2,211 $ 1,726 Share-Based Compensation The Company recognizes compensation expense for share-based awards, including stock options and restricted stock and restricted stock units (collectively, restricted shares), on a straight-line basis over the related service period (generally the vesting period) of the award, or to an employee’s eligible retirement date under the award agreement, if earlier. Restricted shares vest ratably, primarily over four Net Earnings Per Common Share The Company computes basic earnings per common share attributable to UnitedHealth Group common shareholders by dividing net earnings attributable to UnitedHealth Group common shareholders by the weighted-average number of common shares outstanding during the period. The Company determines diluted net earnings per common share attributable to UnitedHealth Group common shareholders using the weighted-average number of common shares outstanding during the period, adjusted for potentially dilutive shares associated with stock options, restricted shares and the ESPP (collectively, common stock equivalents), using the treasury stock method. The treasury stock method assumes a hypothetical issuance of shares to settle the share-based awards, with the assumed proceeds used to purchase common stock at the average market price for the period. Assumed proceeds include the amount the employee must pay upon exercise and the average unrecognized compensation cost. The difference between the number of shares assumed issued and number of shares assumed purchased represents the dilutive shares. ACA Tax The ACA included an annual, nondeductible insurance industry tax (Health Insurance Industry Tax) to be levied proportionally across the insurance industry for risk-based health insurance products. After a moratorium in 2019, the industry wide amount of the Health Insurance Industry Tax for 2020, which was primarily borne by the customer, was $15.5 billion, of which the Company’s portion was approximately $3.0 billion. The Health Insurance Industry Tax was permanently repealed by Congress, effective January 1, 2021. Recently Adopted Accounting Standards In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) No. 2016-13, “Financial Instruments - Credit Losses (Topic 326)” (ASU 2016-13). ASU 2016-13 requires the use of the current expected credit loss impairment model to develop an estimate of expected credit losses for certain financial assets. ASU 2016-13 also requires expected credit losses on available-for-sale debt securities to be recognized through an allowance for credit losses and revises certain disclosure requirements. The Company adopted ASU 2016-13 on January 1, 2020 using a cumulative effect upon adoption approach. The adoption of ASU 2016-13 was immaterial to the Company’s consolidated balance sheet, results of operations, equity and cash flows. The Company has determined there have been no other recently adopted or issued accounting standards which had, or will have, a material impact on its Consolidated Financial Statements.

Investments (Notes)

Investments (Notes)	12 Months Ended
	Dec. 31, 2020
Investments [Abstract]
Investments [Text Block]	Investments A summary of debt securities by major security type is as follows: (in millions) Amortized Gross Gross Fair December 31, 2020 Debt securities - available-for-sale: U.S. government and agency obligations $ 3,335 $ 133 $ (3) $ 3,465 State and municipal obligations 6,893 435 — 7,328 Corporate obligations 18,886 863 (12) 19,737 U.S. agency mortgage-backed securities 6,849 245 (3) 7,091 Non-U.S. agency mortgage-backed securities 2,116 95 (4) 2,207 Total debt securities - available-for-sale 38,079 1,771 (22) 39,828 Debt securities - held-to-maturity: U.S. government and agency obligations 420 6 — 426 State and municipal obligations 31 2 — 33 Corporate obligations 187 1 — 188 Total debt securities - held-to-maturity 638 9 — 647 Total debt securities $ 38,717 $ 1,780 $ (22) $ 40,475 December 31, 2019 Debt securities - available-for-sale: U.S. government and agency obligations $ 3,502 $ 55 $ (4) $ 3,553 State and municipal obligations 5,680 251 (5) 5,926 Corporate obligations 17,910 343 (11) 18,242 U.S. agency mortgage-backed securities 6,425 109 (6) 6,528 Non-U.S. agency mortgage-backed securities 1,811 37 (3) 1,845 Total debt securities - available-for-sale 35,328 795 (29) 36,094 Debt securities - held-to-maturity: U.S. government and agency obligations 402 2 — 404 State and municipal obligations 32 2 — 34 Corporate obligations 538 — (1) 537 Total debt securities - held-to-maturity 972 4 (1) 975 Total debt securities $ 36,300 $ 799 $ (30) $ 37,069 Nearly all of the Company’s investments in mortgage-backed securities were rated “Triple A” as of December 31, 2020. The Company held $2.3 billion and $2.0 billion of equity securities as of December 31, 2020 and December 31, 2019, respectively. The Company’s investments in equity securities primarily consist of employee savings plan related investments and shares of Brazilian real denominated fixed-income funds with readily determinable fair values. Additionally, the Company’s investments included $1.3 billion and $1.4 billion of equity method investments in operating businesses in the health care sector, as of December 31, 2020 and 2019, respectively. The allowance for credit losses on held-to-maturity securities at December 31, 2020 was not material. The amortized cost and fair value of debt securities as of December 31, 2020, by contractual maturity, were as follows: Available-for-Sale Held-to-Maturity (in millions) Amortized Fair Amortized Fair Due in one year or less $ 2,951 $ 2,966 $ 348 $ 349 Due after one year through five years 11,638 12,088 241 245 Due after five years through ten years 10,212 10,931 27 29 Due after ten years 4,313 4,545 22 24 U.S. agency mortgage-backed securities 6,849 7,091 — — Non-U.S. agency mortgage-backed securities 2,116 2,207 — — Total debt securities $ 38,079 $ 39,828 $ 638 $ 647 The fair value of available-for-sale debt securities 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 12 Months or Greater Total (in millions) Fair Gross Fair Gross Fair Gross December 31, 2020 U.S. government and agency obligations $ 346 $ (3) $ — $ — $ 346 $ (3) Corporate obligations 1,273 (9) 456 (3) 1,729 (12) U.S. agency mortgage-backed securities 601 (3) — — 601 (3) Non-U.S. agency mortgage-backed securities 195 (1) 93 (3) 288 (4) Total debt securities - available-for-sale $ 2,415 $ (16) $ 549 $ (6) $ 2,964 $ (22) December 31, 2019 U.S. government and agency obligations $ 616 $ (4) $ — $ — $ 616 $ (4) State and municipal obligations 440 (5) — — 440 (5) Corporate obligations 1,903 (7) 740 (4) 2,643 (11) U.S. agency mortgage-backed securities 657 (3) 333 (3) 990 (6) Non-U.S. agency mortgage-backed securities 406 (3) — — 406 (3) Total debt securities - available-for-sale $ 4,022 $ (22) $ 1,073 $ (7) $ 5,095 $ (29) The Company’s unrealized losses from all securities as of December 31, 2020 were generated from approximately 2,000 positions out of a total of 36,000 positions. The Company believes it will collect the timely principal and interest due on its debt securities having 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 quality associated with these securities which impacted the Company’s assessment on collectability of principal and interest. At each reporting period, the Company evaluates available-for-sale debt securities for any credit-related impairment when the fair value of the investment is less than its amortized cost. The Company evaluated the expected cash flows, the underlying credit quality and credit ratings of the issuers, and the potential economic impacts of COVID-19 on the issuers, noting no significant credit deterioration since purchase. As of December 31, 2020, the Company did not have the intent to sell any of the securities in an unrealized loss position. Therefore, the Company believes these losses to be temporary. The allowance for credit losses on available-for-sale debt securities at December 31, 2020 was not material.

Fair Value (Notes)

Fair Value (Notes)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value [Text Block]	Fair ValueCertain assets and liabilities are measured at fair value in the Consolidated Financial Statements or have fair values disclosed in the Notes to the 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 which 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 inactive markets (e.g., few transactions, limited information, noncurrent prices, high variability over time); • Inputs other than quoted prices observable for the asset/liability (e.g., interest rates, yield curves, implied volatilities, credit spreads); and • Inputs corroborated by other observable market data. Level 3 — Unobservable inputs cannot be corroborated by observable market data. There were no transfers in or out of Level 3 financial assets or liabilities during the years ended December 31, 2020 or 2019. Nonfinancial assets and liabilities or financial assets and liabilities 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 years ended December 31, 2020 or 2019. 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 which 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 currently observable in the markets for similar securities. Inputs often used in the valuation methodologies include, but are not limited to, benchmark yields, credit spreads, default rates, prepayment speeds and nonbinding 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 to the prices obtained from the pricing service. Fair values of debt securities which 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 fair values of Level 3 investments in corporate bonds, which are not a significant portion of our investments, are estimated using valuation techniques relying heavily on management assumptions and qualitative observations. 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 such understanding. Assets Under Management. Assets under management consists of debt securities and other investments held to fund costs associated with the AARP Program and are priced and classified using the same methodologies as the Company’s investments in debt and equity securities. Long-Term Debt. The fair values of the Company’s long-term debt are estimated and classified using the same methodologies as the Company’s investments in debt securities. 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 Consolidated Balance Sheets: (in millions) Quoted Prices Other Unobservable Total December 31, 2020 Cash and cash equivalents $ 16,841 $ 80 $ — $ 16,921 Debt securities - available-for-sale: U.S. government and agency obligations 3,241 224 — 3,465 State and municipal obligations — 7,328 — 7,328 Corporate obligations 25 19,424 288 19,737 U.S. agency mortgage-backed securities — 7,091 — 7,091 Non-U.S. agency mortgage-backed securities — 2,207 — 2,207 Total debt securities - available-for-sale 3,266 36,274 288 39,828 Equity securities 1,795 33 — 1,828 Assets under management 1,774 2,250 52 4,076 Total assets at fair value $ 23,676 $ 38,637 $ 340 $ 62,653 Percentage of total assets at fair value 38 % 61 % 1 % 100 % December 31, 2019 Cash and cash equivalents $ 10,837 $ 148 $ — $ 10,985 Debt securities - available-for-sale: U.S. government and agency obligations 3,369 184 — 3,553 State and municipal obligations — 5,926 — 5,926 Corporate obligations 70 17,923 249 18,242 U.S. agency mortgage-backed securities — 6,528 — 6,528 Non-U.S. agency mortgage-backed securities — 1,845 — 1,845 Total debt securities - available-for-sale 3,439 32,406 249 36,094 Equity securities 1,734 22 — 1,756 Assets under management 1,123 1,918 35 3,076 Total assets at fair value $ 17,133 $ 34,494 $ 284 $ 51,911 Percentage of total assets at fair value 33 % 66 % 1 % 100 % 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 Consolidated Balance Sheets: (in millions) Quoted Prices Other Unobservable Total Total Carrying Value December 31, 2020 Debt securities - held-to-maturity $ 466 $ 108 $ 73 $ 647 $ 638 Long-term debt and other financing obligations $ — $ 51,254 $ — $ 51,254 $ 42,171 December 31, 2019 Debt securities - held-to-maturity $ 541 $ 181 $ 253 $ 975 $ 972 Long-term debt and other financing obligations $ — $ 45,078 $ — $ 45,078 $ 40,278

Property, Plant, and Capitalize

Property, Plant, and Capitalized Software (Notes)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment Disclosure [Text Block]	Property, Equipment and Capitalized Software A summary of property, equipment and capitalized software is as follows: (in millions) December 31, 2020 December 31, 2019 Land and improvements $ 533 $ 589 Buildings and improvements 4,759 4,705 Computer equipment 1,767 2,015 Furniture and fixtures 1,787 1,752 Less accumulated depreciation (3,364) (3,328) Property and equipment, net 5,482 5,733 Capitalized software 5,010 4,638 Less accumulated amortization (1,866) (1,667) Capitalized software, net 3,144 2,971 Total property, equipment and capitalized software, net $ 8,626 $ 8,704

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Notes)	12 Months Ended
	Dec. 31, 2020
Goodwill [Line Items]
Goodwill Disclosure [Text Block]	Goodwill and Other Intangible Assets Changes in the carrying amount of goodwill, by reportable segment, were as follows: (in millions) UnitedHealthcare OptumHealth OptumInsight OptumRx Consolidated Balance at January 1, 2019 $ 26,400 $ 11,947 $ 5,772 $ 14,791 $ 58,910 Acquisitions 1,022 3,395 2,521 6 6,944 Foreign currency effects and other adjustments, net (194) — (1) — (195) Balance at December 31, 2019 27,228 15,342 8,292 14,797 65,659 Acquisitions 1,180 4,500 — 699 6,379 Foreign currency effects and other adjustments, net (623) 2 (119) 39 (701) Balance at December 31, 2020 $ 27,785 $ 19,844 $ 8,173 $ 15,535 $ 71,337 The gross carrying value, accumulated amortization and net carrying value of other intangible assets were as follows: December 31, 2020 December 31, 2019 (in millions) Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value Customer-related $ 13,428 $ (4,575) $ 8,853 $ 12,968 $ (4,319) $ 8,649 Trademarks and technology 1,597 (624) 973 1,186 (525) 661 Trademarks and other indefinite-lived 680 — 680 726 — 726 Other 606 (256) 350 541 (228) 313 Total $ 16,311 $ (5,455) $ 10,856 $ 15,421 $ (5,072) $ 10,349 The acquisition date fair values and weighted-average useful lives assigned to finite-lived intangible assets acquired in business combinations consisted of the following by year of acquisition: 2020 2019 (in millions, except years) Fair Value Weighted-Average Useful Life Fair Value Weighted-Average Useful Life Customer-related $ 1,113 11 years $ 1,750 13 years Trademarks and technology 514 10 years 163 5 years Other 95 10 years 119 11 years Total acquired finite-lived intangible assets $ 1,722 11 years $ 2,032 13 years Estimated full year amortization expense relating to intangible assets for each of the next five years ending December 31 is as follows: (in millions) 2021 $ 1,105 2022 998 2023 933 2024 887 2025 850

Medical Costs Payable (Notes)

Medical Costs Payable (Notes)	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Medical Costs Payable	Medical Costs Payable The following table shows the components of the change in medical costs payable for the years ended December 31: (in millions) 2020 2019 2018 Medical costs payable, beginning of period $ 21,690 $ 19,891 $ 17,871 Acquisitions 316 679 339 Reported medical costs: Current year 160,276 157,020 145,723 Prior years (880) (580) (320) Total reported medical costs 159,396 156,440 145,403 Medical payments: Payments for current year (139,974) (137,155) (127,155) Payments for prior years (19,556) (18,165) (16,567) Total medical payments (159,530) (155,320) (143,722) Medical costs payable, end of period $ 21,872 $ 21,690 $ 19,891 For the years ended December 31, 2020 and 2019 medical cost reserve development was primarily driven by lower than expected health system utilization levels. For the year ended December 31, 2018, no individual factors significantly impacted medical cost reserve development. Medical costs payable included IBNR of $14.8 billion and $13.8 billion at December 31, 2020 and 2019, respectively. Substantially all of the IBNR balance as of December 31, 2020 relates to the current year. The following is information about incurred and paid medical cost development as of December 31, 2020: Net Incurred Medical Costs (in millions) For the Years Ended December 31, Year 2019 2020 2019 $ 157,020 $ 156,217 2020 160,276 Total $ 316,493 Net Cumulative Medical Payments (in millions) For the Years Ended December 31, Year 2019 2020 2019 $ (137,155) $ (155,150) 2020 (139,974) Total (295,124) Net remaining outstanding liabilities prior to 2019 503 Total medical costs payable $ 21,872

Short-Term Borrowings and Long-

Short-Term Borrowings and Long-Term Debt (Notes)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Short-Term Borrowings and Long-Term Debt [Text Block]	Short-Term Borrowings and Long-Term Debt Short-term borrowings and senior unsecured long-term debt consisted of the following: December 31, 2020 December 31, 2019 (in millions, except percentages) Par Value Carrying Value Fair Value Par Value Carrying Value Fair Value Commercial paper $ 1,296 $ 1,296 $ 1,296 $ 400 $ 400 $ 400 2.700% notes due July 2020 — — — 1,500 1,499 1,506 Floating rate notes due October 2020 — — — 300 300 300 3.875% notes due October 2020 — — — 450 450 455 1.950% notes due October 2020 — — — 900 899 900 4.700% notes due February 2021 400 400 401 400 403 410 2.125% notes due March 2021 750 750 753 750 749 753 Floating rate notes due June 2021 350 350 350 350 349 350 3.150% notes due June 2021 400 400 405 400 399 407 3.375% notes due November 2021 500 507 509 500 501 512 2.875% notes due December 2021 750 762 768 750 753 765 2.875% notes due March 2022 1,100 1,113 1,127 1,100 1,087 1,121 3.350% notes due July 2022 1,000 999 1,048 1,000 998 1,036 2.375% notes due October 2022 900 897 935 900 896 911 0.000% notes due November 2022 15 14 14 15 13 14 2.750% notes due February 2023 625 644 654 625 624 638 2.875% notes due March 2023 750 789 793 750 770 770 3.500% notes due June 2023 750 748 809 750 747 786 3.500% notes due February 2024 750 747 821 750 746 792 2.375% notes due August 2024 750 747 799 750 747 760 3.750% notes due July 2025 2,000 1,992 2,279 2,000 1,990 2,161 3.700% notes due December 2025 300 298 344 300 298 325 1.250% notes due January 2026 500 496 515 — — — 3.100% notes due March 2026 1,000 997 1,121 1,000 996 1,048 3.450% notes due January 2027 750 747 859 750 746 804 3.375% notes due April 2027 625 620 714 625 620 667 2.950% notes due October 2027 950 940 1,067 950 939 988 3.850% notes due June 2028 1,150 1,143 1,367 1,150 1,142 1,269 3.875% notes due December 2028 850 844 1,019 850 843 941 2.875% notes due August 2029 1,000 1,086 1,137 1,000 993 1,029 2.000% notes due May 2030 1,250 1,234 1,326 — — — 4.625% notes due July 2035 1,000 992 1,340 1,000 992 1,215 5.800% notes due March 2036 850 839 1,271 850 838 1,129 6.500% notes due June 2037 500 492 800 500 492 712 6.625% notes due November 2037 650 641 1,044 650 641 940 6.875% notes due February 2038 1,100 1,077 1,802 1,100 1,076 1,631 3.500% notes due August 2039 1,250 1,241 1,487 1,250 1,241 1,313 2.750% notes due May 2040 1,000 964 1,085 — — — 5.700% notes due October 2040 300 296 451 300 296 396 5.950% notes due February 2041 350 346 540 350 345 475 4.625% notes due November 2041 600 589 820 600 589 716 4.375% notes due March 2042 502 485 661 502 484 580 3.950% notes due October 2042 625 608 790 625 607 688 4.250% notes due March 2043 750 735 982 750 735 856 4.750% notes due July 2045 2,000 1,974 2,814 2,000 1,973 2,463 4.200% notes due January 2047 750 738 991 750 738 861 4.250% notes due April 2047 725 717 963 725 717 839 3.750% notes due October 2047 950 934 1,180 950 934 1,023 4.250% notes due June 2048 1,350 1,330 1,803 1,350 1,330 1,569 4.450% notes due December 2048 1,100 1,086 1,517 1,100 1,086 1,316 3.700% notes due August 2049 1,250 1,235 1,567 1,250 1,235 1,344 2.900% notes due May 2050 1,250 1,208 1,384 — — — 3.875% notes due August 2059 1,250 1,228 1,618 1,250 1,228 1,350 3.125% notes due May 2060 1,000 965 1,161 — — — Total short-term borrowings and long-term debt $ 42,563 $ 42,280 $ 51,301 $ 39,817 $ 39,474 $ 44,234 The Company’s long-term debt obligations also included $1.2 billion of other financing obligations as of both December 31, 2020 and 2019, of which $354 million and $322 million were current as of December 31, 2020 and 2019, respectively. Maturities of short-term borrowings and long-term debt for the years ending December 31 are as follows: (in millions) 2021 $ 4,800 2022 3,180 2023 2,290 2024 1,665 2025 2,465 Thereafter 29,349 Short-Term Borrowings Commercial paper consists of short-duration, senior unsecured debt privately placed on a discount basis through broker-dealers. As of December 31, 2020, the Company’s outstanding commercial paper had a weighted-average annual interest rate of 0.2%. The Company has $4.4 billion five-year, $4.4 billion three-year and $3.8 billion 364-day revolving bank credit facilities with 26 banks, which mature in December 2025, December 2023 and December 2021, respectively. These facilities provide full liquidity support for the Company’s commercial paper program and are available for general corporate purposes. As of December 31, 2020, no amounts had been drawn on any of the bank credit facilities. The annual interest rates, which are variable based on term, are calculated based on the London Interbank Offered Rate (LIBOR) plus a credit spread based on the Company’s senior unsecured credit ratings. If amounts had been drawn on the bank credit facilities as of December 31, 2020, annual interest rates would have ranged from 0.8% to 1.0%. Debt Covenants The Company’s bank credit facilities contain various covenants, including requiring the Company to maintain a debt to debt-plus-shareholders’ equity ratio of not more than 60%. The Company was in compliance with its debt covenants as of December 31, 2020.

Income Taxes (Notes)

Income Taxes (Notes)	12 Months Ended
	Dec. 31, 2020
Income Tax Examination [Line Items]
Income Tax Disclosure [Text Block]	Income Taxes The current income tax provision reflects the tax consequences of revenues and expenses currently taxable or deductible on various income tax returns for the year reported. The deferred income tax provision or benefit generally reflects the net change in deferred income tax assets and liabilities during the year, excluding any deferred income tax assets and liabilities of acquired businesses. The components of the provision for income taxes for the years ended December 31 are as follows: (in millions) 2020 2019 2018 Current Provision: Federal $ 4,098 $ 2,629 $ 2,897 State and local 392 319 219 Foreign 491 564 404 Total current provision 4,981 3,512 3,520 Deferred (benefit) provision (8) 230 42 Total provision for income taxes $ 4,973 $ 3,742 $ 3,562 The reconciliation of the tax provision at the U.S. federal statutory rate to the provision for income taxes and the effective tax rate for the years ended December 31 is as follows: (in millions, except percentages) 2020 2019 2018 Tax provision at the U.S. federal statutory rate $ 4,356 21.0 % $ 3,776 21.0 % $ 3,348 21.0 % State income taxes, net of federal benefit 315 1.5 271 1.5 168 1.0 Share-based awards - excess tax benefit (130) (0.6) (132) (0.7) (161) (1.0) Non-deductible compensation 134 0.7 119 0.7 117 0.7 Health insurance tax 626 3.0 — — 552 3.5 Foreign rate differential (164) (0.8) (214) (1.2) (203) (1.3) Other, net (164) (0.8) (78) (0.5) (259) (1.6) Provision for income taxes $ 4,973 24.0 % $ 3,742 20.8 % $ 3,562 22.3 % Deferred income tax assets and liabilities are recognized for the differences between the financial and income tax reporting bases of assets and liabilities based on enacted tax rates and laws. The components of deferred income tax assets and liabilities as of December 31 are as follows: (in millions) 2020 2019 Deferred income tax assets: Accrued expenses and allowances $ 815 $ 654 U.S. federal and state net operating loss carryforwards 276 260 Share-based compensation 98 97 Nondeductible liabilities 252 184 Non-U.S. tax loss carryforwards 340 420 Lease liability 1,200 892 Other-domestic 126 179 Other-non-U.S. 454 329 Subtotal 3,561 3,015 Less: valuation allowances (170) (147) Total deferred income tax assets 3,391 2,868 Deferred income tax liabilities: U.S. federal and state intangible assets (2,588) (2,370) Non-U.S. goodwill and intangible assets (606) (735) Capitalized software (731) (683) Depreciation and amortization (346) (301) Prepaid expenses (216) (172) Outside basis in partnerships (342) (317) Lease right-of-use asset (1,179) (887) Net unrealized gains on investments (400) (177) Other-non-U.S. (350) (219) Total deferred income tax liabilities (6,758) (5,861) Net deferred income tax liabilities $ (3,367) $ (2,993) Valuation allowances are provided when it is considered more likely than not deferred tax assets will not be realized. The valuation allowances primarily relate to future tax benefits on certain federal, state and non-U.S. net operating loss carryforwards. Gross federal net operating loss carryforwards of $100 million expire beginning in 2023 through 2037 and $309 million have an indefinite carryforward period; state net operating loss carryforwards expire beginning in 2021 through 2040, with some having an indefinite carryforward period. Substantially all of the non-U.S. tax loss carryforwards have indefinite carryforward periods. As of December 31, 2020, the Company’s undistributed earnings from non-U.S. subsidiaries are intended to be indefinitely reinvested in non-U.S. operations, and therefore no U.S. deferred taxes have been recorded. Taxes payable on the remittance of such earnings would be minimal. A reconciliation of the beginning and ending amount of unrecognized tax benefits as of December 31 is as follows: (in millions) 2020 2019 2018 Gross unrecognized tax benefits, beginning of period $ 1,423 $ 1,056 $ 598 Gross increases: Current year tax positions 416 512 487 Prior year tax positions 120 2 87 Gross decreases: Prior year tax positions (130) (96) (84) Settlements — (46) (20) Statute of limitations lapses — (5) (12) Gross unrecognized tax benefits, end of period $ 1,829 $ 1,423 $ 1,056 The Company believes it is reasonably possible its liability for unrecognized tax benefits will decrease in the next twelve months by $39 million as a result of audit settlements and the expiration of statutes of limitations. The Company classifies interest and penalties associated with uncertain income tax positions as income taxes within its Consolidated Statements of Operations. During the years ended December 31, 2020, 2019 and 2018, the Company recognized $52 million, $19 million and $6 million of interest and penalties, respectively. The Company had $128 million and $76 million of accrued interest and penalties for uncertain tax positions as of December 31, 2020 and 2019, respectively. These amounts are not included in the reconciliation above. As of December 31, 2020, there were $1.0 billion of unrecognized tax benefits which, if recognized, would affect the effective tax rate. The Company currently files income tax returns in the United States, various states and localities and non-U.S. jurisdictions. The U.S. Internal Revenue Service (IRS) has completed exams on the consolidated income tax returns for fiscal years 2016 and prior. The Company’s 2017 through 2020 tax years are under review by the IRS under its Compliance Assurance Program. With the exception of a few states, the Company is no longer subject to income tax examinations prior to the 2013 tax year. In general, the Company is subject to examination in non-U.S. jurisdictions for years 2015 and forward.

Shareholders' Equity (Notes)

Shareholders' Equity (Notes)	12 Months Ended
	Dec. 31, 2020
Shareholders' Equity [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	Shareholders' Equity Regulatory Capital and Dividend Restrictions The Company’s regulated insurance and health maintenance organization (HMO) subsidiaries are subject to regulations and standards in their respective jurisdictions. These standards, among other things, require these subsidiaries to maintain specified levels of statutory capital, as defined by each jurisdiction, and restrict the timing and amount of dividends and other distributions which may be paid to their parent companies. In the United States, most of these state regulations and standards are generally consistent with model regulations established by the National Association of Insurance Commissioners. These standards generally permit dividends to be paid from statutory unassigned surplus of the regulated subsidiary and are limited based on the regulated subsidiary’s level of statutory net income and statutory capital and surplus. These dividends are referred to as “ordinary dividends” and generally may be paid without prior regulatory approval. If the dividend, together with other dividends paid within the preceding twelve months, exceeds a specified statutory limit or is paid from sources other than earned surplus, it is generally considered an “extraordinary dividend” and must receive prior regulatory approval. For the year ended December 31, 2020, the Company’s domestic insurance and HMO subsidiaries paid their parent companies dividends of $8.3 billion, including $4.2 billion of extraordinary dividends. For the year ended December 31, 2019, the Company’s domestic insurance and HMO subsidiaries paid their parent companies dividends of $5.6 billion, including $1.3 billion of extraordinary dividends. The Company's global financially regulated subsidiaries had estimated aggregate statutory capital and surplus of $29.6 billion as of December 31, 2020. The estimated statutory capital and surplus necessary to satisfy regulatory requirements of the Company's global financially regulated subsidiaries was approximately $11.9 billion as of December 31, 2020. Optum Bank must meet minimum capital requirements of the Federal Deposit Insurance Corporation (FDIC) under the capital adequacy rules to which it is subject. At December 31, 2020, the Company believes Optum Bank met the FDIC requirements to be considered “Well Capitalized.” 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 2018, the Board renewed the Company’s share repurchase program with an authorization to repurchase up to 100 million shares of its common stock. A summary of common share repurchases for the years ended December 31, 2020 and 2019 is as follows: Years Ended December 31, (in millions, except per share data) 2020 2019 Common share repurchases, shares 14 22 Common share repurchases, average price per share $ 300.58 $ 245.97 Common share repurchases, aggregate cost $ 4,250 $ 5,500 Board authorized shares remaining 58 72 Dividends In June 2020, the Company’s Board of Directors increased the Company’s quarterly cash dividend to shareholders to an annual rate of $5.00 compared to $4.32 per share, which the Company had paid since June 2019. 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 2020 dividend payments: Payment Date Amount per Share Total Amount Paid (in millions) March 24 $ 1.08 $ 1,024 June 30 1.25 1,188 September 22 1.25 1,188 December 15 1.25 1,184

Share-Based Compensation (Notes

Share-Based Compensation (Notes)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Share-based Payment Arrangement [Text Block]	Share-Based Compensation The Company’s outstanding share-based awards consist mainly of non-qualified stock options and restricted shares. In June 2020, the Company’s Board of Directors approved 48 million additional shares under the Plan. As of December 31, 2020, the Company had 71 million shares available for future grants of share-based awards under the Plan. As of December 31, 2020, there were also 4 million shares of common stock available for issuance under the ESPP. Stock Options Stock option activity for the year ended December 31, 2020 is summarized in the table below: Shares Weighted- Weighted- Aggregate (in millions) (in years) (in millions) Outstanding at beginning of period 32 $ 166 Granted 7 311 Exercised (10) 126 Forfeited (1) 255 Outstanding at end of period 28 211 6.6 $ 3,937 Exercisable at end of period 13 150 5.0 2,579 Vested and expected to vest, end of period 27 210 6.5 3,892 Restricted Shares Restricted share activity for the year ended December 31, 2020 is summarized in the table below: (shares in millions) Shares Weighted-Average Nonvested at beginning of period 5 $ 207 Granted 1 303 Vested (2) 187 Nonvested at end of period 4 256 Other Share-Based Compensation Data (in millions, except per share amounts) For the Years Ended December 31, 2020 2019 2018 Stock Options Weighted-average grant date fair value of shares granted, per share $ 54 $ 46 $ 43 Total intrinsic value of stock options exercised 1,736 1,398 1,431 Restricted Shares Weighted-average grant date fair value of shares granted, per share 303 259 229 Total fair value of restricted shares vested $ 574 $ 545 $ 521 Employee Stock Purchase Plan Number of shares purchased 1 1 2 Share-Based Compensation Items Share-based compensation expense, before tax $ 679 $ 697 $ 638 Share-based compensation expense, net of tax effects 619 641 587 Income tax benefit realized from share-based award exercises 208 201 239 (in millions, except years) December 31, 2020 Unrecognized compensation expense related to share awards $ 805 Weighted-average years to recognize compensation expense 1.4 Share-Based Compensation Recognition and Estimates The principal assumptions the Company used in calculating grant-date fair value for stock options were as follows: For the Years Ended December 31, 2020 2019 2018 Risk-free interest rate 0.2% - 1.4% 1.5% - 2.5% 2.6% - 3.1% Expected volatility 22.2% - 29.5% 19.4% - 21.6% 18.7% - 19.3% Expected dividend yield 1.4% - 1.7% 1.4% - 1.8% 1.3% - 1.5% Forfeiture rate 5.0% 5.0% 5.0% Expected life in years 5.1 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 exercises and forfeitures within the valuation model. The expected lives of options granted represents the period of time the awards granted are expected to be outstanding based on historical exercise patterns. Other Employee Benefit Plans The Company offers a 401(k) plan for its employees. Compensation expense related to this plan was not material for 2020, 2019 and 2018.

Commitments and Contingencies (

Commitments and Contingencies (Notes)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies Leases Operating lease costs were $1.1 billion, $1.0 billion and $751 million for the years ended December 31, 2020, 2019 and 2018, respectively, and included immaterial variable and short-term lease costs for the year ended December 31, 2020 and 2019. Cash payments made on the Company’s operating lease liabilities were $865 million and $746 million for the years ended December 31, 2020 and 2019, respectively, which were classified within operating activities in the Consolidated Statements of Cash Flows. As of December 31, 2020, the Company’s weighted-average remaining lease term and weighted-average discount rate for its operating leases were 8.7 years and 3.0%, respectively. As of December 31, 2020, future minimum annual lease payments under all non-cancelable operating leases were as follows: (in millions) Future Minimum Lease Payments 2021 $ 865 2022 775 2023 646 2024 538 2025 441 Thereafter 1,781 Total future minimum lease payments 5,046 Less imputed interest (599) Total $ 4,447 Other Commitments The Company provides guarantees related to its service level under certain contracts. If minimum standards are not met, the Company may be financially at risk up to a stated percentage of the contracted fee or a stated dollar amount. None of the amounts accrued, paid or charged to income for service level guarantees were material as of December 31, 2020, 2019 or 2018. As of December 31, 2020, the Company had outstanding, undrawn letters of credit with financial institutions of $134 million and surety bonds outstanding with insurance companies of $1.2 billion, primarily to bond contractual performance. Pending Acquisitions In the fourth quarter of 2020, the Company entered into agreements to acquire multiple companies in the health care sector, which are expected to close in the first half of 2021, subject to regulatory approval and other customary closing conditions. Additionally, in January 2021, the Company entered into agreements to purchase multiple companies in the health care sector, most notably, Change Healthcare (NASDAQ: CHNG). This acquisition is expected to close in the second half of 2021, subject to Change Healthcare shareholders’ approval, regulatory approvals and other customary closing conditions. The total anticipated capital required for these acquisitions, excluding the payoff of acquired indebtedness, is approximately $13 billion. 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 a loss may be incurred. Government Investigations, Audits and Reviews The Company has been involved 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 (DOJ), the SEC, the IRS, the U.S. Drug Enforcement Administration, the U.S. Department of Labor, the FDIC, the Defense Contract Audit Agency and other governmental authorities. Similarly, our international businesses are also subject to investigations, audits and reviews by applicable foreign governments, including South American and other non-U.S. governmental authorities. Certain of the Company’s businesses have been reviewed or are currently under review, including for, among other matters, compliance with coding and other requirements under the Medicare risk-adjustment model. CMS has selected certain of the Company’s local plans for risk adjustment data validation (RADV) audits to validate the coding practices of and supporting documentation maintained by health care providers and such audits may result in retrospective adjustments to payments made to the Company’s health plans. On February 14, 2017, the DOJ announced its decision to pursue certain claims within a lawsuit initially asserted against the Company and filed under seal by a whistleblower in 2011. The whistleblower’s complaint, which was unsealed on February 15, 2017, alleges the Company made improper risk adjustment submissions and violated the False Claims Act. On February 12, 2018, the court granted in part and denied in part the Company’s motion to dismiss. In May 2018, DOJ moved to dismiss the Company’s counterclaims, which were filed in March 2018, and moved for partial summary judgment. In March 2019, the court denied the government’s motion for partial summary judgment and dismissed the Company’s counterclaims without prejudice. The Company cannot reasonably estimate the outcome which may result from this matter given its procedural status.

Business Combinations Business

Business Combinations Business Combinations (Notes)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Business Combination Disclosure [Text Block]	Business Combinations During the year ended December 31, 2020, the Company completed several business combinations for total cash consideration of $7.9 billion. The total consideration exceeded the fair value of the net tangible assets acquired by $8.1 billion, of which $1.7 billion has been allocated to finite-lived intangible assets and $6.4 billion to goodwill. The majority of goodwill is not deductible for income tax purposes. Acquired tangible assets (liabilities) at acquisition date were: (in millions) Cash and cash equivalents $ 715 Accounts receivable and other current assets 735 Property, equipment and other long-term assets 816 Medical costs payable (316) Accounts payable and other current liabilities (861) Other long-term liabilities (817) Total net tangible assets $ 272 The preliminary purchase price allocations for the various business combinations are subject to adjustment as valuation analyses, primarily related to intangible assets and contingent and tax liabilities, are finalized. See Note 6 for a summary of the acquisition date fair values and weighted-average useful lives assigned to acquired finite-lived intangible assets. The results of operations and financial condition of acquired entities have been included in the Company’s consolidated results and the results of the corresponding operating segment as of date of acquisition. Through December 31, 2020, acquired entities impact on revenue and net earnings was not material. Unaudited pro forma revenues for the years ended December 31, 2020 and 2019 as if the acquisitions had occurred on January 1, 2019 were immaterial for both periods. The pro forma effects of the acquisitions on net earnings were immaterial for both years.

Segment Financial Information (

Segment Financial Information (Notes)	12 Months Ended
	Dec. 31, 2020
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 used by the Company’s chief operating decision maker to evaluate its results of operations. Reportable segments with similar economic characteristics, products and services, customers, distribution methods and operational processes which operate in a similar regulatory environment are combined. The following is a description of the types of products and services from which each of the Company’s four reportable segments derives its revenues: • UnitedHealthcare includes the combined results of operations of UnitedHealthcare Employer & Individual, UnitedHealthcare Medicare & Retirement, UnitedHealthcare Community & State and UnitedHealthcare Global. The U.S. businesses share significant common assets, including a contracted network of physicians, health care professionals, hospitals and other facilities, information technology and consumer engagement infrastructure and other resources. UnitedHealthcare Employer & Individual offers an array of consumer-oriented health benefit plans and services for large national employers, public sector employers, mid-sized employers, small businesses and individuals nationwide. UnitedHealthcare Medicare & Retirement provides health care coverage and health and well-being services to individuals age 50 and older, addressing their unique needs for preventive and acute health care services as well as services dealing with chronic disease and other specialized issues for older individuals. UnitedHealthcare Community & State provides diversified health care benefits products and services to state programs caring for the economically disadvantaged and the medically underserved. UnitedHealthcare Community & State’s primary customers oversee Medicaid plans, the Children’s Health Insurance Program and other federal, state and community health care programs. UnitedHealthcare Global provides health and dental benefits and hospital and clinical services to employer groups and individuals in South America, and other diversified global health businesses. • OptumHealth focuses on care delivery, care management, wellness and consumer engagement, and health financial services. OptumHealth is building a comprehensive, connected health care delivery and engagement platform by directly providing high-quality care, helping people manage chronic and complex health needs, and proactively engaging consumers in managing their health through in-person, virtual and digital clinical platforms. OptumHealth offers access to networks of care provider specialists, health management services, care delivery, consumer engagement and financial services. • OptumInsight brings together advanced analytics, technology and health care expertise to deliver integrated services and solutions. Hospital systems, physicians, health plans, governments, life sciences companies and other organizations comprising the health care industry depend on OptumInsight to help them improve performance, achieve efficiency, reduce costs, meet compliance mandates and modernize their core operating systems to meet the changing needs of the health system. • OptumRx offers pharmacy care services and programs, including retail network contracting, home delivery, specialty and community health pharmacy services, purchasing and clinical capabilities, and develops programs in areas such as step therapy, formulary management, drug adherence and disease/drug therapy management. OptumRx integrates pharmacy and medical care and is positioned to serve patients with complex clinical needs and consumers looking for a better digital pharmacy experience with transparent pricing. The Company’s accounting policies for reportable segment operations are consistent with those described in the Summary of Significant Accounting Policies (see Note 2 ). Transactions between reportable segments principally consist of sales of pharmacy care products and services to UnitedHealthcare customers by OptumRx, certain product offerings and care management and local 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. Transactions with affiliated customers are eliminated in consolidation. Assets and liabilities jointly used are assigned to each reportable segment using estimates of pro-rata usage. Cash and investments are assigned so each reportable segment has working capital and/or at least minimum specified levels of regulatory capital. As a percentage of the Company’s total consolidated revenues, premium revenues from CMS were 36%, 33% and 30% for 2020, 2019 and 2018, respectively, most of which were generated by UnitedHealthcare Medicare & Retirement and included in the UnitedHealthcare segment. U.S. customer revenue represented approximately 97%, 96% and 96% of consolidated total revenues for 2020, 2019 and 2018, respectively. Long-lived fixed assets located in the United States represented approximately 75% and 72% of the total long-lived fixed assets as of December 31, 2020 and 2019, respectively. The non-U.S. revenues and fixed assets are primarily related to UnitedHealthcare Global. The following table presents the reportable segment financial information: Optum (in millions) UnitedHealthcare OptumHealth OptumInsight OptumRx Optum Eliminations Optum Corporate and Consolidated 2020 Revenues - unaffiliated customers: Premiums $ 191,679 $ 9,799 $ — $ — $ — $ 9,799 $ — $ 201,478 Products — 33 135 33,977 — 34,145 — 34,145 Services 8,464 6,815 3,687 1,050 — 11,552 — 20,016 Total revenues - unaffiliated customers 200,143 16,647 3,822 35,027 — 55,496 — 255,639 Total revenues - affiliated customers — 22,481 6,941 52,420 (1,800) 80,042 (80,042) — Investment and other income 732 680 39 51 — 770 — 1,502 Total revenues $ 200,875 $ 39,808 $ 10,802 $ 87,498 $ (1,800) $ 136,308 $ (80,042) $ 257,141 Earnings from operations $ 12,359 $ 3,434 $ 2,725 $ 3,887 $ — $ 10,046 $ — $ 22,405 Interest expense — — — — — — (1,663) (1,663) Earnings before income taxes $ 12,359 $ 3,434 $ 2,725 $ 3,887 $ — $ 10,046 $ (1,663) $ 20,742 Total assets $ 98,229 $ 52,073 $ 15,425 $ 39,280 $ — $ 106,778 $ (7,718) $ 197,289 Purchases of property, equipment and capitalized software 687 715 461 188 — 1,364 — 2,051 Depreciation and amortization 920 703 670 598 — 1,971 — 2,891 2019 Revenues - unaffiliated customers: Premiums $ 183,783 $ 5,916 $ — $ — $ — $ 5,916 $ — $ 189,699 Products — 31 116 31,450 — 31,597 — 31,597 Services 8,922 5,732 3,630 689 — 10,051 — 18,973 Total revenues - unaffiliated customers 192,705 11,679 3,746 32,139 — 47,564 — 240,269 Total revenues - affiliated customers — 17,966 6,239 42,093 (1,661) 64,637 (64,637) — Investment and other income 1,137 672 21 56 — 749 — 1,886 Total revenues $ 193,842 $ 30,317 $ 10,006 $ 74,288 $ (1,661) $ 112,950 $ (64,637) $ 242,155 Earnings from operations $ 10,326 $ 2,963 $ 2,494 $ 3,902 $ — $ 9,359 $ — $ 19,685 Interest expense — — — — — — (1,704) (1,704) Earnings before income taxes $ 10,326 $ 2,963 $ 2,494 $ 3,902 $ — $ 9,359 $ (1,704) $ 17,981 Total assets $ 88,250 $ 40,444 $ 15,181 $ 36,346 $ — $ 91,971 $ (6,332) $ 173,889 Purchases of property, equipment and capitalized software 841 573 495 162 — 1,230 — 2,071 Depreciation and amortization 926 565 672 557 — 1,794 — 2,720 2018 Revenues - unaffiliated customers: Premiums $ 174,282 $ 3,805 $ — $ — $ — $ 3,805 $ — $ 178,087 Products — 52 111 29,438 — 29,601 — 29,601 Services 8,366 4,925 3,280 612 — 8,817 — 17,183 Total revenues - unaffiliated customers 182,648 8,782 3,391 30,050 — 42,223 — 224,871 Total revenues - affiliated customers — 14,882 5,596 39,440 (1,409) 58,509 (58,509) — Investment and other income 828 481 21 46 — 548 — 1,376 Total revenues $ 183,476 $ 24,145 $ 9,008 $ 69,536 $ (1,409) $ 101,280 $ (58,509) $ 226,247 Earnings from operations $ 9,113 $ 2,430 $ 2,243 $ 3,558 $ — $ 8,231 $ — $ 17,344 Interest expense — — — — — — (1,400) (1,400) Earnings before income taxes $ 9,113 $ 2,430 $ 2,243 $ 3,558 $ — $ 8,231 $ (1,400) $ 15,944 Total assets $ 82,938 $ 29,837 $ 11,039 $ 33,912 $ — $ 74,788 $ (5,505) $ 152,221 Purchases of property, equipment and capitalized software 761 593 517 192 — 1,302 — 2,063 Depreciation and amortization 845 439 654 490 — 1,583 — 2,428

Schedule I (Notes)

Schedule I (Notes)	12 Months Ended
	Dec. 31, 2020
Condensed Statement of Income Captions [Line Items]
Condensed Financial Information of Parent Company Only Disclosure [Text Block]	Schedule I Condensed Financial Information of Registrant (Parent Company Only) UnitedHealth Group Condensed Balance Sheets (in millions, except per share data) December 31, December 31, Assets Current assets: Cash and cash equivalents $ 258 $ 46 Other current assets 562 787 Total current assets 820 833 Equity in net assets of subsidiaries 107,714 93,467 Long-term notes receivable from subsidiaries 5,021 5,079 Other assets 342 794 Total assets $ 113,897 $ 100,173 Liabilities and shareholders’ equity Current liabilities: Accounts payable and accrued liabilities $ 589 $ 688 Current portion of notes payable to subsidiaries 4,882 750 Short-term borrowings and current maturities of long-term debt 4,465 3,548 Total current liabilities 9,936 4,986 Long-term debt, less current maturities 37,815 35,926 Long-term notes payable to subsidiaries — 1,314 Other liabilities 655 331 Total liabilities 48,406 42,557 Commitments and contingencies (Note 4) Shareholders’ equity: Preferred stock, $0.001 par value -10 shares authorized; no shares issued or outstanding — — Common stock, $0.01 par value - 3,000 shares authorized; 946 and 948 issued and outstanding 10 9 Additional paid-in capital — 7 Retained earnings 69,295 61,178 Accumulated other comprehensive loss (3,814) (3,578) Total UnitedHealth Group shareholders’ equity 65,491 57,616 Total liabilities and shareholders’ equity $ 113,897 $ 100,173 See Notes to the Condensed Financial Statements of Registrant Schedule I Condensed Financial Information of Registrant (Parent Company Only) UnitedHealth Group Condensed Statements of Comprehensive Income For the Years Ended December 31, (in millions) 2020 2019 2018 Revenues: Investment and other income $ 194 $ 209 $ 194 Total revenues 194 209 194 Operating costs: Operating costs 27 38 35 Interest expense 1,594 1,580 1,285 Total operating costs 1,621 1,618 1,320 Loss before income taxes (1,427) (1,409) (1,126) Benefit for income taxes 300 293 251 Loss of parent company (1,127) (1,116) (875) Equity in undistributed income of subsidiaries 16,530 14,955 12,861 Net earnings 15,403 13,839 11,986 Other comprehensive (loss) income (236) 582 (1,517) Comprehensive income $ 15,167 $ 14,421 $ 10,469 See Notes to the Condensed Financial Statements of Registrant Schedule I Condensed Financial Information of Registrant (Parent Company Only) UnitedHealth Group Condensed Statements of Cash Flows For the Years Ended December 31, (in millions) 2020 2019 2018 Operating activities Cash flows from operating activities $ 8,842 $ 9,275 $ 6,099 Investing activities Issuances of notes to subsidiaries (628) (2,722) (1,420) Repayments of notes to subsidiaries 1,089 2,249 1,419 Cash paid for acquisitions (7,706) (9,645) (4,066) Return of capital to parent company 943 4,497 4,196 Capital contributions to subsidiaries (43) (803) (1,259) Other, net 143 490 4 Cash flows used for investing activities (6,202) (5,934) (1,126) Financing activities Common stock repurchases (4,250) (5,500) (4,500) Proceeds from common stock issuances 1,440 1,037 838 Cash dividends paid (4,584) (3,932) (3,320) Proceeds from (repayments of) short-term borrowings, net 872 300 (201) Proceeds from issuance of long-term debt 4,864 5,444 6,935 Repayments of long-term debt (3,150) (1,750) (2,600) Proceeds (repayments) of notes from subsidiaries 2,818 1,207 (1,127) Other, net (438) (535) (923) Cash flows used for financing activities (2,428) (3,729) (4,898) Increase (decrease) in cash and cash equivalents 212 (388) 75 Cash and cash equivalents, beginning of period 46 434 359 Cash and cash equivalents, end of period $ 258 $ 46 $ 434 Supplemental cash flow disclosures Cash paid for interest $ 1,633 $ 1,506 $ 1,294 Cash paid for income taxes 4,185 2,590 2,379 See Notes to the Condensed Financial Statements of Registrant Schedule I Condensed Financial Information of Registrant (Parent Company Only) UnitedHealth Group Notes to Condensed Financial Statements 1. Basis of Presentation UnitedHealth Group’s parent company financial information has been derived from its consolidated financial statements and should be read in conjunction with the consolidated financial statements included in this Form 10-K. The accounting policies for the registrant are the same as those described in Note 2 of the Notes to the Consolidated Financial Statements included in Part II, Item 8, “Financial Statements . ” 2. Subsidiary Transactions Investment in Subsidiaries. UnitedHealth Group’s investment in subsidiaries is stated at cost plus equity in undistributed earnings of subsidiaries. Dividends and Capital Distributions. Cash dividends received from subsidiaries and included in Cash Flows from Operating Activities in the Condensed Statements of Cash Flows were $10.0 billion, $5.6 billion and $5.6 billion in 2020, 2019 and 2018, respectively. Additionally, $0.9 billion, $4.5 billion and $4.2 billion in cash were received as a return of capital to the parent company during 2020, 2019 and 2018, respectively. 3. Short-Term Borrowings and Long-Term Debt Discussion of short-term borrowings and long-term debt can be found in Note 8 of the Notes to the Consolidated Financial Statements included in Part II, Item 8, “Financial Statements .” Long-term debt obligations of the parent company do not include other financing obligations at subsidiaries which totaled $1.2 billion at December 31, 2020 and 2019. Maturities of short-term borrowings and long-term debt for the years ending December 31 are as follows: (in millions) 2021 $ 4,446 2022 3,015 2023 2,125 2024 1,500 2025 2,300 Thereafter 29,177 UnitedHealth Group’s parent company had notes payable to subsidiaries of $4.9 billion as of December 31, 2020, which included on-demand features. 4. Commitments and Contingencies Certain regulated subsidiaries are guaranteed by UnitedHealth Group’s parent company in the event of insolvency. UnitedHealth Group’s parent company also provides guarantees related to its service level under certain contracts. None of the amounts accrued, paid or charged to income for service level guarantees were material as of December 31, 2020, 2019 or 2018. For a summary of commitments and contingencies, see Note 12 of the Notes to the Consolidated Financial Statements included in Part II, Item 8, “Financial Statements .”

Basis of Presentation, Uses o_2

Basis of Presentation, Uses of Estimates and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Basis of Accounting, Policy [Policy Text Block]	Basis of PresentationThe Company has prepared the Consolidated Financial Statements according to U.S. Generally Accepted Accounting Principles (GAAP) and has included the accounts of UnitedHealth Group and its subsidiaries.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates These Consolidated Financial Statements include certain amounts based on the Company’s best estimates and judgments. The Company’s most significant estimates relate to estimates and judgments for medical costs payable and goodwill. Certain of these estimates require the application of complex assumptions and judgments, often because they involve matters inherently uncertain and will likely change in subsequent periods. The impact of any change in estimates is included in earnings in the period in which the estimate is adjusted.
Revenue [Policy Text Block]	Revenues Premiums Premium revenues are primarily derived from risk-based health insurance arrangements in which the premium is typically at a fixed rate per individual served for a one-year period, and the Company assumes the economic risk of funding its customers’ health care and related administrative costs. Premium revenues are recognized in the period in which eligible individuals are entitled to receive health care benefits. Health care premium payments received from the Company’s customers in advance of the service period are recorded as unearned revenues. Fully insured commercial products of U.S. health plans, Medicare Advantage and Medicare Prescription Drug Benefit (Medicare Part D) plans with medical loss ratios (MLRs) as calculated under the definitions in the Patient Protection and Affordable Care Act (ACA) and related federal and state regulations and implementing regulation, falling below certain targets are required to rebate ratable portions of their premiums annually. Commercial premiums within the Company’s individual and small group markets are also subject to the ACA risk adjustment program. Medicare Advantage premium revenue includes the impact of the Centers for Medicare & Medicaid Services (CMS) quality bonuses based on plans’ Star rating. Certain of the Company’s Medicaid business is also subject to state minimum MLR rebates. Premium revenues are recognized based on the estimated premiums earned, net of projected rebates, because the Company is able to reasonably estimate the ultimate premiums of these contracts. The Company also records premium revenues for certain risk-based arrangements at its OptumHealth care delivery businesses. The Company’s Medicare Advantage and Medicare Part D premium revenues are subject to periodic adjustment under CMS’ risk adjustment payment methodology. CMS deploys a risk adjustment model which apportions premiums paid to all health plans according to health severity and certain demographic factors. The CMS risk adjustment model provides higher per member payments for enrollees diagnosed with certain conditions and lower payments for enrollees who are healthier. Under this risk adjustment methodology, CMS calculates the risk adjusted premium payment using diagnosis and encounter data from hospital inpatient, hospital outpatient and physician treatment settings. The Company and health care providers collect, capture and submit the necessary and available data to CMS within prescribed deadlines. The Company estimates risk adjustment premium revenues based upon the data submitted and expected to be submitted to CMS. Risk adjustment data for the Company’s plans are subject to review by the government, including audit by regulators. See Note 12 for additional information regarding these audits. Products and Services For the Company’s OptumRx pharmacy care services business, the majority of revenues are derived from products sold through a contracted network of retail pharmacies or home delivery, specialty and community health pharmacies. Product revenues include the cost of pharmaceuticals (net of rebates), a negotiated dispensing fee and customer co-payments for drugs dispensed through the Company’s home delivery, specialty and community pharmacies. For the year ended December 31, 2020, the Company recognized revenue and cost of products sold for retail pharmacy co-payments related to its OptumRx business. Revenue recognized in prior periods related to retail pharmacy transactions excludes the member’s applicable co-payment. There was no impact on earnings from operations, net earnings, earnings per share or total equity. Pharmacy products are billed to customers based on the number of transactions occurring during the billing period. Product revenues are recognized when the prescriptions are dispensed. The Company has entered into contracts in which it is primarily obligated to pay its network pharmacy providers for benefits provided to their customers regardless of whether the Company is paid. The Company is also involved in establishing the prices charged by retail pharmacies, determining which drugs will be included in formulary listings and selecting which retail pharmacies will be included in the network offered to plan sponsors’ members and accordingly, are reported on a gross basis. Services revenue consists of fees derived from services performed for customers who self-insure the health care costs of their employees and employees’ dependents. Under service fee contracts, the Company receives monthly, a fixed fee per employee, which is recognized as revenue as the Company performs, or makes available, the applicable services to the customer. The customers retain the risk of financing health care costs for their employees and employees’ dependents, and the Company administers the payment of customer funds to physicians and other health care professionals from customer-funded bank accounts. As the Company has neither the obligation for funding the health care costs, nor the primary responsibility for providing the medical care, the Company does not recognize premium revenue and medical costs for these contracts in its Consolidated Financial Statements. For these fee-based customer arrangements, the Company provides coordination and facilitation of medical services; transaction processing; customer, consumer and care professional services; and access to contracted networks of physicians, hospitals and other health care professionals. These services are performed throughout the contract period. Revenues are also comprised of a number of services and products sold through Optum. OptumHealth’s service revenues include net patient service revenues recorded based upon established billing rates, less allowances for contractual adjustments, and are recognized as services are provided. For its financial services offerings, OptumHealth charges fees and earns investment income on managed funds. OptumInsight provides software and information products, advisory consulting arrangements and managed services outsourcing contracts, which may be delivered over several years. OptumInsight revenues are generally recognized over time and measured each period based on the progress to date as services are performed or made available to customers. As of December 31, 2020 and 2019, accounts receivables related to products and services were $5.3 billion and $4.3 billion, respectively. In 2020 and 2019, the Company had no material bad-debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the Consolidated Balance Sheets as of December 31, 2020 or 2019. For the years ended December 31, 2020 and 2019, revenue recognized from performance obligations related to prior periods (for example, due to changes in transaction price) was not material. Revenue expected to be recognized in any future year related to remaining performance obligations, excluding revenue pertaining to contracts having an original expected duration of one year or less, contracts where revenue is recognized as invoiced and contracts with variable consideration related to undelivered performance obligations, is not material. See Note 14 for disaggregation of revenue by segment and type.
Medical Costs and Medical Costs Payable [Policy Text Block]	Medical Costs and Medical Costs Payable The Company’s estimate of medical costs payable represents management’s best estimate of its liability for unpaid medical costs as of December 31, 2020. Each period, the Company re-examines previously established medical costs payable estimates based on actual claim submissions and other changes in facts and circumstances. As more complete claim information becomes available, the Company adjusts the amount of the estimates and includes the changes in estimates in medical costs in the period in which the change is identified. Approximately 90% of claims related to medical care services are known and settled within 90 days from the date of service and substantially all within twelve months. Medical costs and medical costs payable include estimates of the Company’s obligations for medical care services rendered on behalf of insured consumers, but for which claims have either not yet been received, processed, or paid. The Company develops estimates for medical care services incurred but not reported (IBNR), which includes estimates for claims which have not been received or fully processed, using an actuarial process consistently applied, centrally controlled and automated. The actuarial models consider factors such as time from date of service to claim processing, seasonal variances in medical care consumption, health care professional contract rate changes, medical care utilization and other medical cost trends, membership volume and demographics, the introduction of new technologies, benefit plan changes, and business mix changes related to products, customers and geography. Judgments related to these factors contemplated the impact of COVID-19 in 2020.
Cost of Goods and Service [Policy Text Block]	Cost of Products Sold The Company’s cost of products sold includes the cost of pharmaceuticals dispensed to unaffiliated customers either directly at its home delivery, specialty and community pharmacy locations, or indirectly through its nationwide network of participating pharmacies. Rebates attributable to non-affiliated clients are accrued as rebates receivable and a reduction of cost of products sold, with a corresponding payable for the amounts of the rebates to be remitted to those non-affiliated clients in accordance with their contracts and recorded in the Consolidated Statements of Operations as a reduction of product revenue. Cost of products sold also includes the cost of personnel to support the Company’s transaction processing services, system sales, maintenance and professional services.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash, Cash Equivalents and Investments Cash and cash equivalents are highly liquid investments having an original maturity of three months or less. The fair value of cash and cash equivalents approximates their carrying value because of the short maturity of the instruments.
Investment, Policy [Policy Text Block]	Investments with maturities of less than one year are classified as short-term. Because of regulatory requirements, certain investments are included in long-term investments regardless of their maturity date. The Company classifies these investments as held-to-maturity and reports them at amortized cost. Substantially all other investments are classified as available-for-sale and reported at fair value based on quoted market prices, where available. Equity investments, with certain exceptions, are measured at fair value with changes in fair value recognized in net earnings. The Company excludes unrealized gains and losses on investments in available-for-sale debt securities from net earnings and reports them as comprehensive income and, net of income tax effects, as a separate component of equity. To calculate realized gains and losses on the sale of debt securities, the Company specifically identifies the cost of each investment sold. The Company evaluates an available-for-sale debt security for credit-related impairment by considering the present value of expected cash flows relative to a security’s amortized cost, the extent to which fair value is less than amortized cost, the financial condition and near-term prospects of the issuer and specific events or circumstances which may influence the operations of the issuer. Credit-related impairments are recorded as an allowance, with an offset to investment and other income. Non-credit related impairments are recorded through other comprehensive income. If the Company intends to sell an impaired security, or will likely be required to sell a security before recovery of the entire amortized cost, the entire impairment is included in net earnings.
AARP Assets Under Management [Policy Text Block]	Assets Under Management The Company provides health insurance products and services to members of AARP under a Supplemental Health Insurance Program (the AARP Program) and to AARP members and non-members under separate Medicare Advantage and Medicare Part D arrangements. The products and services under the AARP Program include supplemental Medicare benefits, hospital indemnity insurance, including insurance for individuals between 50 to 64 years of age, and other related products. Pursuant to the Company’s agreement with AARP, program assets are managed separately from the Company’s general investment portfolio and are used to pay costs associated with the AARP Program. These assets are invested at the Company’s discretion, within investment guidelines approved by AARP. The Company does not guarantee any rates of return on these investments and, upon any transfer of the AARP Program contract to another entity, the Company would transfer cash equal in amount to the fair value of these investments at the date of transfer to the entity. Because the purpose of these assets is to fund the medical costs payable, the rate stabilization fund (RSF) liabilities and other related liabilities associated with this AARP contract, assets under management are classified as current assets, consistent with the classification of these liabilities. The effects of changes in other balance sheet amounts associated with the AARP Program also accrue to the overall benefit of the AARP policyholders through the RSF balance. Accordingly, the Company excludes the effect of such changes in its Consolidated Statements of Cash Flows.
Receivable [Policy Text Block]	Other Current Receivables Other current receivables include amounts due from pharmaceutical manufacturers for rebates and Medicare Part D drug discounts, accrued interest and other miscellaneous amounts due to the Company. The Company’s pharmacy care services businesses contract with pharmaceutical manufacturers, some of which provide rebates based on use of the manufacturers’ products by its affiliated and non-affiliated clients. The Company accrues rebates as they are earned by its clients on a monthly basis based on the terms of the applicable contracts, historical data and current estimates. The pharmacy care services businesses bill these rebates to the manufacturers on a monthly or quarterly basis depending on the contractual terms and record rebates attributable to affiliated clients as a reduction to medical costs. The Company generally receives rebates two to five months after billing. As of December 31, 2020 and 2019, total pharmaceutical manufacturer rebates receivable included in other receivables in the Consolidated Balance Sheets amounted to $6.3 billion and $4.7 billion, respectively. As of December 31, 2020 and 2019, the Company’s Medicare Part D receivables amounted to $2.9 billion and $2.3 billion, respectively.
Property, Plant and Equipment, Policy [Policy Text Block]	Property, Equipment and Capitalized Software Property, equipment and capitalized software are stated at cost, net of accumulated depreciation and amortization. Capitalized software consists of certain costs incurred in the development of internal-use software, including external direct costs of materials and services and applicable payroll costs of employees devoted to specific software development. The Company calculates depreciation and amortization using the straight-line method over the estimated useful lives of the assets. The useful lives for property, equipment and capitalized software are: Furniture, fixtures and equipment 3 to 10 years Buildings 35 to 40 years Capitalized software 3 to 5 years Leasehold improvements are depreciated over the shorter of the remaining lease term or their estimated useful economic life.
Lessee, Leases [Policy Text Block]	Operating Leases The Company leases facilities and equipment under long-term operating leases which are non-cancelable and expire on various dates. At the lease commencement date, lease right-of-use (ROU) assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term, which includes all fixed obligations arising from the lease contract. If an interest rate is not implicit in a lease, the Company utilizes its incremental borrowing rate for a period closely matching the lease term.
Goodwill and Intangible Assets, Goodwill, Policy [Policy Text Block]	Goodwill To determine whether goodwill is impaired, annually or more frequently if needed, the Company performs impairment tests. The Company may first assess qualitative factors to determine if it is more likely than not the carrying value of a reporting unit exceeds its estimated fair value. The Company may also elect to skip the qualitative testing and proceed directly to the quantitative testing. When performing quantitative testing, the Company first estimates the fair values of its reporting units using discounted cash flows or a weighted combination of discounted cash flows and a market-based method. To determine fair values, the Company must make assumptions about a wide variety of internal and external factors. Significant assumptions used in the impairment analysis include financial projections of free cash flow (including significant assumptions about operations, capital requirements and income taxes), long-term growth rates for determining terminal value, discount rates and the selection of comparable peer companies. If the fair value is less than the carrying value of the reporting unit, an impairment is recognized for the difference, up to the carrying amount of goodwill. There was no impairment of goodwill during the year ended December 31, 2020.
Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block]	Intangible Assets The Company’s intangible assets are subject to impairment tests when events or circumstances indicate an intangible asset (or asset group) may be impaired. The Company’s indefinite-lived intangible assets are also tested for impairment annually. There was no impairment of intangible assets during the year ended December 31, 2020.
Other Current Liabilities [Policy Text Block]	Other Current Liabilities Other current liabilities include health savings account deposits ($10.2 billion and $8.3 billion as of December 31, 2020 and 2019, respectively), the RSF associated with the AARP Program, accruals for premium rebates payable, the current portion of future policy benefits and customer balances.
Deferred Policy Acquisition Costs, Policy [Policy Text Block]	Policy Acquisition Costs The Company’s short duration health insurance contracts typically have a one-year term and may be canceled by the customer with at least 30 days’ notice. Costs related to the acquisition and renewal of short duration customer contracts are primarily charged to expense as incurred.
Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block]	Redeemable Noncontrolling Interests Redeemable noncontrolling interests in the Company’s subsidiaries whose redemption is outside the control of the Company are classified as temporary equity. The following table provides details of the Company's redeemable noncontrolling interests’ activity for the years ended December 31, 2020 and 2019: (in millions) 2020 2019 Redeemable noncontrolling interests, beginning of period $ 1,726 $ 1,908 Net earnings 112 115 Acquisitions 321 90 Redemptions — (618) Distributions (149) (69) Fair value and other adjustments 201 300 Redeemable noncontrolling interests, end of period $ 2,211 $ 1,726
Share-based Payment Arrangement [Policy Text Block]	Share-Based CompensationThe Company recognizes compensation expense for share-based awards, including stock options and restricted stock and restricted stock units (collectively, restricted shares), on a straight-line basis over the related service period (generally the vesting period) of the award, or to an employee’s eligible retirement date under the award agreement, if earlier. Restricted shares vest ratably, primarily over four
Earnings Per Share, Policy [Policy Text Block]	Net Earnings Per Common Share The Company computes basic earnings per common share attributable to UnitedHealth Group common shareholders by dividing net earnings attributable to UnitedHealth Group common shareholders by the weighted-average number of common shares outstanding during the period. The Company determines diluted net earnings per common share attributable to UnitedHealth Group common shareholders using the weighted-average number of common shares outstanding during the period, adjusted for potentially dilutive shares associated with stock options, restricted shares and the ESPP (collectively, common stock equivalents), using the treasury stock method. The treasury stock method assumes a hypothetical issuance of shares to settle the share-based awards, with the assumed proceeds used to purchase common stock at the average market price for the period. Assumed proceeds include the amount the employee must pay upon exercise and the average unrecognized compensation cost. The difference between the number of shares assumed issued and number of shares assumed purchased represents the dilutive shares.
Health Insurance Industry Tax, Policy [Policy Text Block]	ACA Tax The ACA included an annual, nondeductible insurance industry tax (Health Insurance Industry Tax) to be levied proportionally across the insurance industry for risk-based health insurance products. After a moratorium in 2019, the industry wide amount of the Health Insurance Industry Tax for 2020, which was primarily borne by the customer, was $15.5 billion, of which the Company’s portion was approximately $3.0 billion. The Health Insurance Industry Tax was permanently repealed by Congress, effective January 1, 2021.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted Accounting Standards In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) No. 2016-13, “Financial Instruments - Credit Losses (Topic 326)” (ASU 2016-13). ASU 2016-13 requires the use of the current expected credit loss impairment model to develop an estimate of expected credit losses for certain financial assets. ASU 2016-13 also requires expected credit losses on available-for-sale debt securities to be recognized through an allowance for credit losses and revises certain disclosure requirements. The Company adopted ASU 2016-13 on January 1, 2020 using a cumulative effect upon adoption approach. The adoption of ASU 2016-13 was immaterial to the Company’s consolidated balance sheet, results of operations, equity and cash flows. The Company has determined there have been no other recently adopted or issued accounting standards which had, or will have, a material impact on its Consolidated Financial Statements.

Fair Value Fair Value (Policies

Fair Value Fair Value (Policies)	12 Months Ended
	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement, Policy [Policy Text Block]	Certain assets and liabilities are measured at fair value in the Consolidated Financial Statements or have fair values disclosed in the Notes to the 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 which 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 inactive markets (e.g., few transactions, limited information, noncurrent prices, high variability over time); • Inputs other than quoted prices observable for the asset/liability (e.g., interest rates, yield curves, implied volatilities, credit spreads); and • Inputs corroborated by other observable market data. Level 3 — Unobservable inputs cannot be corroborated by observable market data. There were no transfers in or out of Level 3 financial assets or liabilities during the years ended December 31, 2020 or 2019. Nonfinancial assets and liabilities or financial assets and liabilities 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 years ended December 31, 2020 or 2019. 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 which 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 currently observable in the markets for similar securities. Inputs often used in the valuation methodologies include, but are not limited to, benchmark yields, credit spreads, default rates, prepayment speeds and nonbinding 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 to the prices obtained from the pricing service. Fair values of debt securities which 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 fair values of Level 3 investments in corporate bonds, which are not a significant portion of our investments, are estimated using valuation techniques relying heavily on management assumptions and qualitative observations. 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 such understanding. Assets Under Management. Assets under management consists of debt securities and other investments held to fund costs associated with the AARP Program and are priced and classified using the same methodologies as the Company’s investments in debt and equity securities. Long-Term Debt. The fair values of the Company’s long-term debt are estimated and classified using the same methodologies as the Company’s investments in debt securities.

Schedule I (Policies)

Schedule I (Policies)	12 Months Ended
	Dec. 31, 2020
Condensed Financial Statements, Captions [Line Items]
Basis of Presentation and Significant Accounting Policies [Text Block]	Basis of Presentation, Use of Estimates and Significant Accounting Policies Basis of Presentation The Company has prepared the Consolidated Financial Statements according to U.S. Generally Accepted Accounting Principles (GAAP) and has included the accounts of UnitedHealth Group and its subsidiaries. Use of Estimates These Consolidated Financial Statements include certain amounts based on the Company’s best estimates and judgments. The Company’s most significant estimates relate to estimates and judgments for medical costs payable and goodwill. Certain of these estimates require the application of complex assumptions and judgments, often because they involve matters inherently uncertain and will likely change in subsequent periods. The impact of any change in estimates is included in earnings in the period in which the estimate is adjusted. Revenues Premiums Premium revenues are primarily derived from risk-based health insurance arrangements in which the premium is typically at a fixed rate per individual served for a one-year period, and the Company assumes the economic risk of funding its customers’ health care and related administrative costs. Premium revenues are recognized in the period in which eligible individuals are entitled to receive health care benefits. Health care premium payments received from the Company’s customers in advance of the service period are recorded as unearned revenues. Fully insured commercial products of U.S. health plans, Medicare Advantage and Medicare Prescription Drug Benefit (Medicare Part D) plans with medical loss ratios (MLRs) as calculated under the definitions in the Patient Protection and Affordable Care Act (ACA) and related federal and state regulations and implementing regulation, falling below certain targets are required to rebate ratable portions of their premiums annually. Commercial premiums within the Company’s individual and small group markets are also subject to the ACA risk adjustment program. Medicare Advantage premium revenue includes the impact of the Centers for Medicare & Medicaid Services (CMS) quality bonuses based on plans’ Star rating. Certain of the Company’s Medicaid business is also subject to state minimum MLR rebates. Premium revenues are recognized based on the estimated premiums earned, net of projected rebates, because the Company is able to reasonably estimate the ultimate premiums of these contracts. The Company also records premium revenues for certain risk-based arrangements at its OptumHealth care delivery businesses. The Company’s Medicare Advantage and Medicare Part D premium revenues are subject to periodic adjustment under CMS’ risk adjustment payment methodology. CMS deploys a risk adjustment model which apportions premiums paid to all health plans according to health severity and certain demographic factors. The CMS risk adjustment model provides higher per member payments for enrollees diagnosed with certain conditions and lower payments for enrollees who are healthier. Under this risk adjustment methodology, CMS calculates the risk adjusted premium payment using diagnosis and encounter data from hospital inpatient, hospital outpatient and physician treatment settings. The Company and health care providers collect, capture and submit the necessary and available data to CMS within prescribed deadlines. The Company estimates risk adjustment premium revenues based upon the data submitted and expected to be submitted to CMS. Risk adjustment data for the Company’s plans are subject to review by the government, including audit by regulators. See Note 12 for additional information regarding these audits. Products and Services For the Company’s OptumRx pharmacy care services business, the majority of revenues are derived from products sold through a contracted network of retail pharmacies or home delivery, specialty and community health pharmacies. Product revenues include the cost of pharmaceuticals (net of rebates), a negotiated dispensing fee and customer co-payments for drugs dispensed through the Company’s home delivery, specialty and community pharmacies. For the year ended December 31, 2020, the Company recognized revenue and cost of products sold for retail pharmacy co-payments related to its OptumRx business. Revenue recognized in prior periods related to retail pharmacy transactions excludes the member’s applicable co-payment. There was no impact on earnings from operations, net earnings, earnings per share or total equity. Pharmacy products are billed to customers based on the number of transactions occurring during the billing period. Product revenues are recognized when the prescriptions are dispensed. The Company has entered into contracts in which it is primarily obligated to pay its network pharmacy providers for benefits provided to their customers regardless of whether the Company is paid. The Company is also involved in establishing the prices charged by retail pharmacies, determining which drugs will be included in formulary listings and selecting which retail pharmacies will be included in the network offered to plan sponsors’ members and accordingly, are reported on a gross basis. Services revenue consists of fees derived from services performed for customers who self-insure the health care costs of their employees and employees’ dependents. Under service fee contracts, the Company receives monthly, a fixed fee per employee, which is recognized as revenue as the Company performs, or makes available, the applicable services to the customer. The customers retain the risk of financing health care costs for their employees and employees’ dependents, and the Company administers the payment of customer funds to physicians and other health care professionals from customer-funded bank accounts. As the Company has neither the obligation for funding the health care costs, nor the primary responsibility for providing the medical care, the Company does not recognize premium revenue and medical costs for these contracts in its Consolidated Financial Statements. For these fee-based customer arrangements, the Company provides coordination and facilitation of medical services; transaction processing; customer, consumer and care professional services; and access to contracted networks of physicians, hospitals and other health care professionals. These services are performed throughout the contract period. Revenues are also comprised of a number of services and products sold through Optum. OptumHealth’s service revenues include net patient service revenues recorded based upon established billing rates, less allowances for contractual adjustments, and are recognized as services are provided. For its financial services offerings, OptumHealth charges fees and earns investment income on managed funds. OptumInsight provides software and information products, advisory consulting arrangements and managed services outsourcing contracts, which may be delivered over several years. OptumInsight revenues are generally recognized over time and measured each period based on the progress to date as services are performed or made available to customers. As of December 31, 2020 and 2019, accounts receivables related to products and services were $5.3 billion and $4.3 billion, respectively. In 2020 and 2019, the Company had no material bad-debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the Consolidated Balance Sheets as of December 31, 2020 or 2019. For the years ended December 31, 2020 and 2019, revenue recognized from performance obligations related to prior periods (for example, due to changes in transaction price) was not material. Revenue expected to be recognized in any future year related to remaining performance obligations, excluding revenue pertaining to contracts having an original expected duration of one year or less, contracts where revenue is recognized as invoiced and contracts with variable consideration related to undelivered performance obligations, is not material. See Note 14 for disaggregation of revenue by segment and type. Medical Costs and Medical Costs Payable The Company’s estimate of medical costs payable represents management’s best estimate of its liability for unpaid medical costs as of December 31, 2020. Each period, the Company re-examines previously established medical costs payable estimates based on actual claim submissions and other changes in facts and circumstances. As more complete claim information becomes available, the Company adjusts the amount of the estimates and includes the changes in estimates in medical costs in the period in which the change is identified. Approximately 90% of claims related to medical care services are known and settled within 90 days from the date of service and substantially all within twelve months. Medical costs and medical costs payable include estimates of the Company’s obligations for medical care services rendered on behalf of insured consumers, but for which claims have either not yet been received, processed, or paid. The Company develops estimates for medical care services incurred but not reported (IBNR), which includes estimates for claims which have not been received or fully processed, using an actuarial process consistently applied, centrally controlled and automated. The actuarial models consider factors such as time from date of service to claim processing, seasonal variances in medical care consumption, health care professional contract rate changes, medical care utilization and other medical cost trends, membership volume and demographics, the introduction of new technologies, benefit plan changes, and business mix changes related to products, customers and geography. Judgments related to these factors contemplated the impact of COVID-19 in 2020. Cost of Products Sold The Company’s cost of products sold includes the cost of pharmaceuticals dispensed to unaffiliated customers either directly at its home delivery, specialty and community pharmacy locations, or indirectly through its nationwide network of participating pharmacies. Rebates attributable to non-affiliated clients are accrued as rebates receivable and a reduction of cost of products sold, with a corresponding payable for the amounts of the rebates to be remitted to those non-affiliated clients in accordance with their contracts and recorded in the Consolidated Statements of Operations as a reduction of product revenue. Cost of products sold also includes the cost of personnel to support the Company’s transaction processing services, system sales, maintenance and professional services. Cash, Cash Equivalents and Investments Cash and cash equivalents are highly liquid investments having an original maturity of three months or less. The fair value of cash and cash equivalents approximates their carrying value because of the short maturity of the instruments. Investments with maturities of less than one year are classified as short-term. Because of regulatory requirements, certain investments are included in long-term investments regardless of their maturity date. The Company classifies these investments as held-to-maturity and reports them at amortized cost. Substantially all other investments are classified as available-for-sale and reported at fair value based on quoted market prices, where available. Equity investments, with certain exceptions, are measured at fair value with changes in fair value recognized in net earnings. The Company excludes unrealized gains and losses on investments in available-for-sale debt securities from net earnings and reports them as comprehensive income and, net of income tax effects, as a separate component of equity. To calculate realized gains and losses on the sale of debt securities, the Company specifically identifies the cost of each investment sold. The Company evaluates an available-for-sale debt security for credit-related impairment by considering the present value of expected cash flows relative to a security’s amortized cost, the extent to which fair value is less than amortized cost, the financial condition and near-term prospects of the issuer and specific events or circumstances which may influence the operations of the issuer. Credit-related impairments are recorded as an allowance, with an offset to investment and other income. Non-credit related impairments are recorded through other comprehensive income. If the Company intends to sell an impaired security, or will likely be required to sell a security before recovery of the entire amortized cost, the entire impairment is included in net earnings. New information and the passage of time can change these judgments. The Company manages its investment portfolio to limit its exposure to any one issuer or market sector, and largely limits its investments to investment grade quality. Securities downgraded below policy minimums after purchase will be disposed of in accordance with the Company’s investment policy. Assets Under Management The Company provides health insurance products and services to members of AARP under a Supplemental Health Insurance Program (the AARP Program) and to AARP members and non-members under separate Medicare Advantage and Medicare Part D arrangements. The products and services under the AARP Program include supplemental Medicare benefits, hospital indemnity insurance, including insurance for individuals between 50 to 64 years of age, and other related products. Pursuant to the Company’s agreement with AARP, program assets are managed separately from the Company’s general investment portfolio and are used to pay costs associated with the AARP Program. These assets are invested at the Company’s discretion, within investment guidelines approved by AARP. The Company does not guarantee any rates of return on these investments and, upon any transfer of the AARP Program contract to another entity, the Company would transfer cash equal in amount to the fair value of these investments at the date of transfer to the entity. Because the purpose of these assets is to fund the medical costs payable, the rate stabilization fund (RSF) liabilities and other related liabilities associated with this AARP contract, assets under management are classified as current assets, consistent with the classification of these liabilities. The effects of changes in other balance sheet amounts associated with the AARP Program also accrue to the overall benefit of the AARP policyholders through the RSF balance. Accordingly, the Company excludes the effect of such changes in its Consolidated Statements of Cash Flows. Other Current Receivables Other current receivables include amounts due from pharmaceutical manufacturers for rebates and Medicare Part D drug discounts, accrued interest and other miscellaneous amounts due to the Company. The Company’s pharmacy care services businesses contract with pharmaceutical manufacturers, some of which provide rebates based on use of the manufacturers’ products by its affiliated and non-affiliated clients. The Company accrues rebates as they are earned by its clients on a monthly basis based on the terms of the applicable contracts, historical data and current estimates. The pharmacy care services businesses bill these rebates to the manufacturers on a monthly or quarterly basis depending on the contractual terms and record rebates attributable to affiliated clients as a reduction to medical costs. The Company generally receives rebates two to five months after billing. As of December 31, 2020 and 2019, total pharmaceutical manufacturer rebates receivable included in other receivables in the Consolidated Balance Sheets amounted to $6.3 billion and $4.7 billion, respectively. As of December 31, 2020 and 2019, the Company’s Medicare Part D receivables amounted to $2.9 billion and $2.3 billion, respectively. Property, Equipment and Capitalized Software Property, equipment and capitalized software are stated at cost, net of accumulated depreciation and amortization. Capitalized software consists of certain costs incurred in the development of internal-use software, including external direct costs of materials and services and applicable payroll costs of employees devoted to specific software development. The Company calculates depreciation and amortization using the straight-line method over the estimated useful lives of the assets. The useful lives for property, equipment and capitalized software are: Furniture, fixtures and equipment 3 to 10 years Buildings 35 to 40 years Capitalized software 3 to 5 years Leasehold improvements are depreciated over the shorter of the remaining lease term or their estimated useful economic life. Operating Leases The Company leases facilities and equipment under long-term operating leases which are non-cancelable and expire on various dates. At the lease commencement date, lease right-of-use (ROU) assets and lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term, which includes all fixed obligations arising from the lease contract. If an interest rate is not implicit in a lease, the Company utilizes its incremental borrowing rate for a period closely matching the lease term. The Company’s ROU assets are included in other assets, and lease liabilities are included in other current liabilities and other liabilities in the Company’s Consolidated Balance Sheet. Goodwill To determine whether goodwill is impaired, annually or more frequently if needed, the Company performs impairment tests. The Company may first assess qualitative factors to determine if it is more likely than not the carrying value of a reporting unit exceeds its estimated fair value. The Company may also elect to skip the qualitative testing and proceed directly to the quantitative testing. When performing quantitative testing, the Company first estimates the fair values of its reporting units using discounted cash flows or a weighted combination of discounted cash flows and a market-based method. To determine fair values, the Company must make assumptions about a wide variety of internal and external factors. Significant assumptions used in the impairment analysis include financial projections of free cash flow (including significant assumptions about operations, capital requirements and income taxes), long-term growth rates for determining terminal value, discount rates and the selection of comparable peer companies. If the fair value is less than the carrying value of the reporting unit, an impairment is recognized for the difference, up to the carrying amount of goodwill. There was no impairment of goodwill during the year ended December 31, 2020. Intangible Assets The Company’s intangible assets are subject to impairment tests when events or circumstances indicate an intangible asset (or asset group) may be impaired. The Company’s indefinite-lived intangible assets are also tested for impairment annually. There was no impairment of intangible assets during the year ended December 31, 2020. Other Current Liabilities Other current liabilities include health savings account deposits ($10.2 billion and $8.3 billion as of December 31, 2020 and 2019, respectively), the RSF associated with the AARP Program, accruals for premium rebates payable, the current portion of future policy benefits and customer balances. Policy Acquisition Costs The Company’s short duration health insurance contracts typically have a one-year term and may be canceled by the customer with at least 30 days’ notice. Costs related to the acquisition and renewal of short duration customer contracts are primarily charged to expense as incurred. Redeemable Noncontrolling Interests Redeemable noncontrolling interests in the Company’s subsidiaries whose redemption is outside the control of the Company are classified as temporary equity. The following table provides details of the Company's redeemable noncontrolling interests’ activity for the years ended December 31, 2020 and 2019: (in millions) 2020 2019 Redeemable noncontrolling interests, beginning of period $ 1,726 $ 1,908 Net earnings 112 115 Acquisitions 321 90 Redemptions — (618) Distributions (149) (69) Fair value and other adjustments 201 300 Redeemable noncontrolling interests, end of period $ 2,211 $ 1,726 Share-Based Compensation The Company recognizes compensation expense for share-based awards, including stock options and restricted stock and restricted stock units (collectively, restricted shares), on a straight-line basis over the related service period (generally the vesting period) of the award, or to an employee’s eligible retirement date under the award agreement, if earlier. Restricted shares vest ratably, primarily over four Net Earnings Per Common Share The Company computes basic earnings per common share attributable to UnitedHealth Group common shareholders by dividing net earnings attributable to UnitedHealth Group common shareholders by the weighted-average number of common shares outstanding during the period. The Company determines diluted net earnings per common share attributable to UnitedHealth Group common shareholders using the weighted-average number of common shares outstanding during the period, adjusted for potentially dilutive shares associated with stock options, restricted shares and the ESPP (collectively, common stock equivalents), using the treasury stock method. The treasury stock method assumes a hypothetical issuance of shares to settle the share-based awards, with the assumed proceeds used to purchase common stock at the average market price for the period. Assumed proceeds include the amount the employee must pay upon exercise and the average unrecognized compensation cost. The difference between the number of shares assumed issued and number of shares assumed purchased represents the dilutive shares. ACA Tax The ACA included an annual, nondeductible insurance industry tax (Health Insurance Industry Tax) to be levied proportionally across the insurance industry for risk-based health insurance products. After a moratorium in 2019, the industry wide amount of the Health Insurance Industry Tax for 2020, which was primarily borne by the customer, was $15.5 billion, of which the Company’s portion was approximately $3.0 billion. The Health Insurance Industry Tax was permanently repealed by Congress, effective January 1, 2021. Recently Adopted Accounting Standards In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) No. 2016-13, “Financial Instruments - Credit Losses (Topic 326)” (ASU 2016-13). ASU 2016-13 requires the use of the current expected credit loss impairment model to develop an estimate of expected credit losses for certain financial assets. ASU 2016-13 also requires expected credit losses on available-for-sale debt securities to be recognized through an allowance for credit losses and revises certain disclosure requirements. The Company adopted ASU 2016-13 on January 1, 2020 using a cumulative effect upon adoption approach. The adoption of ASU 2016-13 was immaterial to the Company’s consolidated balance sheet, results of operations, equity and cash flows. The Company has determined there have been no other recently adopted or issued accounting standards which had, or will have, a material impact on its Consolidated Financial Statements.
Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block]	Redeemable Noncontrolling Interests Redeemable noncontrolling interests in the Company’s subsidiaries whose redemption is outside the control of the Company are classified as temporary equity. The following table provides details of the Company's redeemable noncontrolling interests’ activity for the years ended December 31, 2020 and 2019: (in millions) 2020 2019 Redeemable noncontrolling interests, beginning of period $ 1,726 $ 1,908 Net earnings 112 115 Acquisitions 321 90 Redemptions — (618) Distributions (149) (69) Fair value and other adjustments 201 300 Redeemable noncontrolling interests, end of period $ 2,211 $ 1,726
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Basis of Presentation and Significant Accounting Policies [Text Block]	Basis of Presentation UnitedHealth Group’s parent company financial information has been derived from its consolidated financial statements and should be read in conjunction with the consolidated financial statements included in this Form 10-K. The accounting policies for the registrant are the same as those described in Note 2 of the Notes to the Consolidated Financial Statements included in Part II, Item 8, “Financial Statements . ”
Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block]	Subsidiary Transactions Investment in Subsidiaries. UnitedHealth Group’s investment in subsidiaries is stated at cost plus equity in undistributed earnings of subsidiaries.

Basis of Presentation, Uses o_3

Basis of Presentation, Uses of Estimates and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Table Text Block]	A summary of property, equipment and capitalized software is as follows: (in millions) December 31, 2020 December 31, 2019 Land and improvements $ 533 $ 589 Buildings and improvements 4,759 4,705 Computer equipment 1,767 2,015 Furniture and fixtures 1,787 1,752 Less accumulated depreciation (3,364) (3,328) Property and equipment, net 5,482 5,733 Capitalized software 5,010 4,638 Less accumulated amortization (1,866) (1,667) Capitalized software, net 3,144 2,971 Total property, equipment and capitalized software, net $ 8,626 $ 8,704
Redeemable Noncontrolling Interest [Table Text Block]	The following table provides details of the Company's redeemable noncontrolling interests’ activity for the years ended December 31, 2020 and 2019: (in millions) 2020 2019 Redeemable noncontrolling interests, beginning of period $ 1,726 $ 1,908 Net earnings 112 115 Acquisitions 321 90 Redemptions — (618) Distributions (149) (69) Fair value and other adjustments 201 300 Redeemable noncontrolling interests, end of period $ 2,211 $ 1,726
Useful Life [Member]
Property, Plant and Equipment [Table Text Block]	The Company calculates depreciation and amortization using the straight-line method over the estimated useful lives of the assets. The useful lives for property, equipment and capitalized software are: Furniture, fixtures and equipment 3 to 10 years Buildings 35 to 40 years Capitalized software 3 to 5 years

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Short-Term and Long-Term Investments [Table Text Block]	A summary of debt securities by major security type is as follows: (in millions) Amortized Gross Gross Fair December 31, 2020 Debt securities - available-for-sale: U.S. government and agency obligations $ 3,335 $ 133 $ (3) $ 3,465 State and municipal obligations 6,893 435 — 7,328 Corporate obligations 18,886 863 (12) 19,737 U.S. agency mortgage-backed securities 6,849 245 (3) 7,091 Non-U.S. agency mortgage-backed securities 2,116 95 (4) 2,207 Total debt securities - available-for-sale 38,079 1,771 (22) 39,828 Debt securities - held-to-maturity: U.S. government and agency obligations 420 6 — 426 State and municipal obligations 31 2 — 33 Corporate obligations 187 1 — 188 Total debt securities - held-to-maturity 638 9 — 647 Total debt securities $ 38,717 $ 1,780 $ (22) $ 40,475 December 31, 2019 Debt securities - available-for-sale: U.S. government and agency obligations $ 3,502 $ 55 $ (4) $ 3,553 State and municipal obligations 5,680 251 (5) 5,926 Corporate obligations 17,910 343 (11) 18,242 U.S. agency mortgage-backed securities 6,425 109 (6) 6,528 Non-U.S. agency mortgage-backed securities 1,811 37 (3) 1,845 Total debt securities - available-for-sale 35,328 795 (29) 36,094 Debt securities - held-to-maturity: U.S. government and agency obligations 402 2 — 404 State and municipal obligations 32 2 — 34 Corporate obligations 538 — (1) 537 Total debt securities - held-to-maturity 972 4 (1) 975 Total debt securities $ 36,300 $ 799 $ (30) $ 37,069
Investments by Contractual Maturity [Table Text Block]	The amortized cost and fair value of debt securities as of December 31, 2020, by contractual maturity, were as follows: Available-for-Sale Held-to-Maturity (in millions) Amortized Fair Amortized Fair Due in one year or less $ 2,951 $ 2,966 $ 348 $ 349 Due after one year through five years 11,638 12,088 241 245 Due after five years through ten years 10,212 10,931 27 29 Due after ten years 4,313 4,545 22 24 U.S. agency mortgage-backed securities 6,849 7,091 — — Non-U.S. agency mortgage-backed securities 2,116 2,207 — — Total debt securities $ 38,079 $ 39,828 $ 638 $ 647
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 debt securities 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 12 Months or Greater Total (in millions) Fair Gross Fair Gross Fair Gross December 31, 2020 U.S. government and agency obligations $ 346 $ (3) $ — $ — $ 346 $ (3) Corporate obligations 1,273 (9) 456 (3) 1,729 (12) U.S. agency mortgage-backed securities 601 (3) — — 601 (3) Non-U.S. agency mortgage-backed securities 195 (1) 93 (3) 288 (4) Total debt securities - available-for-sale $ 2,415 $ (16) $ 549 $ (6) $ 2,964 $ (22) December 31, 2019 U.S. government and agency obligations $ 616 $ (4) $ — $ — $ 616 $ (4) State and municipal obligations 440 (5) — — 440 (5) Corporate obligations 1,903 (7) 740 (4) 2,643 (11) U.S. agency mortgage-backed securities 657 (3) 333 (3) 990 (6) Non-U.S. agency mortgage-backed securities 406 (3) — — 406 (3) Total debt securities - available-for-sale $ 4,022 $ (22) $ 1,073 $ (7) $ 5,095 $ (29)

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2020
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 Consolidated Balance Sheets: (in millions) Quoted Prices Other Unobservable Total December 31, 2020 Cash and cash equivalents $ 16,841 $ 80 $ — $ 16,921 Debt securities - available-for-sale: U.S. government and agency obligations 3,241 224 — 3,465 State and municipal obligations — 7,328 — 7,328 Corporate obligations 25 19,424 288 19,737 U.S. agency mortgage-backed securities — 7,091 — 7,091 Non-U.S. agency mortgage-backed securities — 2,207 — 2,207 Total debt securities - available-for-sale 3,266 36,274 288 39,828 Equity securities 1,795 33 — 1,828 Assets under management 1,774 2,250 52 4,076 Total assets at fair value $ 23,676 $ 38,637 $ 340 $ 62,653 Percentage of total assets at fair value 38 % 61 % 1 % 100 % December 31, 2019 Cash and cash equivalents $ 10,837 $ 148 $ — $ 10,985 Debt securities - available-for-sale: U.S. government and agency obligations 3,369 184 — 3,553 State and municipal obligations — 5,926 — 5,926 Corporate obligations 70 17,923 249 18,242 U.S. agency mortgage-backed securities — 6,528 — 6,528 Non-U.S. agency mortgage-backed securities — 1,845 — 1,845 Total debt securities - available-for-sale 3,439 32,406 249 36,094 Equity securities 1,734 22 — 1,756 Assets under management 1,123 1,918 35 3,076 Total assets at fair value $ 17,133 $ 34,494 $ 284 $ 51,911 Percentage of total assets at fair value 33 % 66 % 1 % 100 %
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 Consolidated Balance Sheets: (in millions) Quoted Prices Other Unobservable Total Total Carrying Value December 31, 2020 Debt securities - held-to-maturity $ 466 $ 108 $ 73 $ 647 $ 638 Long-term debt and other financing obligations $ — $ 51,254 $ — $ 51,254 $ 42,171 December 31, 2019 Debt securities - held-to-maturity $ 541 $ 181 $ 253 $ 975 $ 972 Long-term debt and other financing obligations $ — $ 45,078 $ — $ 45,078 $ 40,278

Property, Plant, and Capitali_2

Property, Plant, and Capitalized Software (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment [Table Text Block]	A summary of property, equipment and capitalized software is as follows: (in millions) December 31, 2020 December 31, 2019 Land and improvements $ 533 $ 589 Buildings and improvements 4,759 4,705 Computer equipment 1,767 2,015 Furniture and fixtures 1,787 1,752 Less accumulated depreciation (3,364) (3,328) Property and equipment, net 5,482 5,733 Capitalized software 5,010 4,638 Less accumulated amortization (1,866) (1,667) Capitalized software, net 3,144 2,971 Total property, equipment and capitalized software, net $ 8,626 $ 8,704

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill [Line Items]
Schedule of Goodwill [Table Text Block]	Changes in the carrying amount of goodwill, by reportable segment, were as follows: (in millions) UnitedHealthcare OptumHealth OptumInsight OptumRx Consolidated Balance at January 1, 2019 $ 26,400 $ 11,947 $ 5,772 $ 14,791 $ 58,910 Acquisitions 1,022 3,395 2,521 6 6,944 Foreign currency effects and other adjustments, net (194) — (1) — (195) Balance at December 31, 2019 27,228 15,342 8,292 14,797 65,659 Acquisitions 1,180 4,500 — 699 6,379 Foreign currency effects and other adjustments, net (623) 2 (119) 39 (701) Balance at December 31, 2020 $ 27,785 $ 19,844 $ 8,173 $ 15,535 $ 71,337
Schedule of Acquired Finite-Lived Intangible Assets by Major Class [Table Text Block]	The gross carrying value, accumulated amortization and net carrying value of other intangible assets were as follows: December 31, 2020 December 31, 2019 (in millions) Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value Customer-related $ 13,428 $ (4,575) $ 8,853 $ 12,968 $ (4,319) $ 8,649 Trademarks and technology 1,597 (624) 973 1,186 (525) 661 Trademarks and other indefinite-lived 680 — 680 726 — 726 Other 606 (256) 350 541 (228) 313 Total $ 16,311 $ (5,455) $ 10,856 $ 15,421 $ (5,072) $ 10,349
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block]	The acquisition date fair values and weighted-average useful lives assigned to finite-lived intangible assets acquired in business combinations consisted of the following by year of acquisition: 2020 2019 (in millions, except years) Fair Value Weighted-Average Useful Life Fair Value Weighted-Average Useful Life Customer-related $ 1,113 11 years $ 1,750 13 years Trademarks and technology 514 10 years 163 5 years Other 95 10 years 119 11 years Total acquired finite-lived intangible assets $ 1,722 11 years $ 2,032 13 years
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	Estimated full year amortization expense relating to intangible assets for each of the next five years ending December 31 is as follows: (in millions) 2021 $ 1,105 2022 998 2023 933 2024 887 2025 850

Medical Costs Payable (Tables)

Medical Costs Payable (Tables)	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]	The following table shows the components of the change in medical costs payable for the years ended December 31: (in millions) 2020 2019 2018 Medical costs payable, beginning of period $ 21,690 $ 19,891 $ 17,871 Acquisitions 316 679 339 Reported medical costs: Current year 160,276 157,020 145,723 Prior years (880) (580) (320) Total reported medical costs 159,396 156,440 145,403 Medical payments: Payments for current year (139,974) (137,155) (127,155) Payments for prior years (19,556) (18,165) (16,567) Total medical payments (159,530) (155,320) (143,722) Medical costs payable, end of period $ 21,872 $ 21,690 $ 19,891
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Table Text Block]	The following is information about incurred and paid medical cost development as of December 31, 2020: Net Incurred Medical Costs (in millions) For the Years Ended December 31, Year 2019 2020 2019 $ 157,020 $ 156,217 2020 160,276 Total $ 316,493 Net Cumulative Medical Payments (in millions) For the Years Ended December 31, Year 2019 2020 2019 $ (137,155) $ (155,150) 2020 (139,974) Total (295,124) Net remaining outstanding liabilities prior to 2019 503 Total medical costs payable $ 21,872

Short-Term Borrowings and Lon_2

Short-Term Borrowings and Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Instrument [Line Items]
Short-Term Borrowings and Long-Term Debt [Table Text Block]	Short-term borrowings and senior unsecured long-term debt consisted of the following: December 31, 2020 December 31, 2019 (in millions, except percentages) Par Value Carrying Value Fair Value Par Value Carrying Value Fair Value Commercial paper $ 1,296 $ 1,296 $ 1,296 $ 400 $ 400 $ 400 2.700% notes due July 2020 — — — 1,500 1,499 1,506 Floating rate notes due October 2020 — — — 300 300 300 3.875% notes due October 2020 — — — 450 450 455 1.950% notes due October 2020 — — — 900 899 900 4.700% notes due February 2021 400 400 401 400 403 410 2.125% notes due March 2021 750 750 753 750 749 753 Floating rate notes due June 2021 350 350 350 350 349 350 3.150% notes due June 2021 400 400 405 400 399 407 3.375% notes due November 2021 500 507 509 500 501 512 2.875% notes due December 2021 750 762 768 750 753 765 2.875% notes due March 2022 1,100 1,113 1,127 1,100 1,087 1,121 3.350% notes due July 2022 1,000 999 1,048 1,000 998 1,036 2.375% notes due October 2022 900 897 935 900 896 911 0.000% notes due November 2022 15 14 14 15 13 14 2.750% notes due February 2023 625 644 654 625 624 638 2.875% notes due March 2023 750 789 793 750 770 770 3.500% notes due June 2023 750 748 809 750 747 786 3.500% notes due February 2024 750 747 821 750 746 792 2.375% notes due August 2024 750 747 799 750 747 760 3.750% notes due July 2025 2,000 1,992 2,279 2,000 1,990 2,161 3.700% notes due December 2025 300 298 344 300 298 325 1.250% notes due January 2026 500 496 515 — — — 3.100% notes due March 2026 1,000 997 1,121 1,000 996 1,048 3.450% notes due January 2027 750 747 859 750 746 804 3.375% notes due April 2027 625 620 714 625 620 667 2.950% notes due October 2027 950 940 1,067 950 939 988 3.850% notes due June 2028 1,150 1,143 1,367 1,150 1,142 1,269 3.875% notes due December 2028 850 844 1,019 850 843 941 2.875% notes due August 2029 1,000 1,086 1,137 1,000 993 1,029 2.000% notes due May 2030 1,250 1,234 1,326 — — — 4.625% notes due July 2035 1,000 992 1,340 1,000 992 1,215 5.800% notes due March 2036 850 839 1,271 850 838 1,129 6.500% notes due June 2037 500 492 800 500 492 712 6.625% notes due November 2037 650 641 1,044 650 641 940 6.875% notes due February 2038 1,100 1,077 1,802 1,100 1,076 1,631 3.500% notes due August 2039 1,250 1,241 1,487 1,250 1,241 1,313 2.750% notes due May 2040 1,000 964 1,085 — — — 5.700% notes due October 2040 300 296 451 300 296 396 5.950% notes due February 2041 350 346 540 350 345 475 4.625% notes due November 2041 600 589 820 600 589 716 4.375% notes due March 2042 502 485 661 502 484 580 3.950% notes due October 2042 625 608 790 625 607 688 4.250% notes due March 2043 750 735 982 750 735 856 4.750% notes due July 2045 2,000 1,974 2,814 2,000 1,973 2,463 4.200% notes due January 2047 750 738 991 750 738 861 4.250% notes due April 2047 725 717 963 725 717 839 3.750% notes due October 2047 950 934 1,180 950 934 1,023 4.250% notes due June 2048 1,350 1,330 1,803 1,350 1,330 1,569 4.450% notes due December 2048 1,100 1,086 1,517 1,100 1,086 1,316 3.700% notes due August 2049 1,250 1,235 1,567 1,250 1,235 1,344 2.900% notes due May 2050 1,250 1,208 1,384 — — — 3.875% notes due August 2059 1,250 1,228 1,618 1,250 1,228 1,350 3.125% notes due May 2060 1,000 965 1,161 — — — Total short-term borrowings and long-term debt $ 42,563 $ 42,280 $ 51,301 $ 39,817 $ 39,474 $ 44,234
Schedule of Maturities of Long-term Debt [Table Text Block]	Maturities of short-term borrowings and long-term debt for the years ending December 31 are as follows: (in millions) 2021 $ 4,800 2022 3,180 2023 2,290 2024 1,665 2025 2,465 Thereafter 29,349

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Contingency [Line Items]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The components of the provision for income taxes for the years ended December 31 are as follows: (in millions) 2020 2019 2018 Current Provision: Federal $ 4,098 $ 2,629 $ 2,897 State and local 392 319 219 Foreign 491 564 404 Total current provision 4,981 3,512 3,520 Deferred (benefit) provision (8) 230 42 Total provision for income taxes $ 4,973 $ 3,742 $ 3,562
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	The reconciliation of the tax provision at the U.S. federal statutory rate to the provision for income taxes and the effective tax rate for the years ended December 31 is as follows: (in millions, except percentages) 2020 2019 2018 Tax provision at the U.S. federal statutory rate $ 4,356 21.0 % $ 3,776 21.0 % $ 3,348 21.0 % State income taxes, net of federal benefit 315 1.5 271 1.5 168 1.0 Share-based awards - excess tax benefit (130) (0.6) (132) (0.7) (161) (1.0) Non-deductible compensation 134 0.7 119 0.7 117 0.7 Health insurance tax 626 3.0 — — 552 3.5 Foreign rate differential (164) (0.8) (214) (1.2) (203) (1.3) Other, net (164) (0.8) (78) (0.5) (259) (1.6) Provision for income taxes $ 4,973 24.0 % $ 3,742 20.8 % $ 3,562 22.3 %
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	The components of deferred income tax assets and liabilities as of December 31 are as follows: (in millions) 2020 2019 Deferred income tax assets: Accrued expenses and allowances $ 815 $ 654 U.S. federal and state net operating loss carryforwards 276 260 Share-based compensation 98 97 Nondeductible liabilities 252 184 Non-U.S. tax loss carryforwards 340 420 Lease liability 1,200 892 Other-domestic 126 179 Other-non-U.S. 454 329 Subtotal 3,561 3,015 Less: valuation allowances (170) (147) Total deferred income tax assets 3,391 2,868 Deferred income tax liabilities: U.S. federal and state intangible assets (2,588) (2,370) Non-U.S. goodwill and intangible assets (606) (735) Capitalized software (731) (683) Depreciation and amortization (346) (301) Prepaid expenses (216) (172) Outside basis in partnerships (342) (317) Lease right-of-use asset (1,179) (887) Net unrealized gains on investments (400) (177) Other-non-U.S. (350) (219) Total deferred income tax liabilities (6,758) (5,861) Net deferred income tax liabilities $ (3,367) $ (2,993)
Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table Text Block]	A reconciliation of the beginning and ending amount of unrecognized tax benefits as of December 31 is as follows: (in millions) 2020 2019 2018 Gross unrecognized tax benefits, beginning of period $ 1,423 $ 1,056 $ 598 Gross increases: Current year tax positions 416 512 487 Prior year tax positions 120 2 87 Gross decreases: Prior year tax positions (130) (96) (84) Settlements — (46) (20) Statute of limitations lapses — (5) (12) Gross unrecognized tax benefits, end of period $ 1,829 $ 1,423 $ 1,056

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Shareholders' Equity [Abstract]
Share Repurchase Activity	A summary of common share repurchases for the years ended December 31, 2020 and 2019 is as follows: Years Ended December 31, (in millions, except per share data) 2020 2019 Common share repurchases, shares 14 22 Common share repurchases, average price per share $ 300.58 $ 245.97 Common share repurchases, aggregate cost $ 4,250 $ 5,500 Board authorized shares remaining 58 72
Dividends Declared	The following table provides details of the Company’s 2020 dividend payments: Payment Date Amount per Share Total Amount Paid (in millions) March 24 $ 1.08 $ 1,024 June 30 1.25 1,188 September 22 1.25 1,188 December 15 1.25 1,184

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock Option Activity [Table Text Block]	Stock option activity for the year ended December 31, 2020 is summarized in the table below: Shares Weighted- Weighted- Aggregate (in millions) (in years) (in millions) Outstanding at beginning of period 32 $ 166 Granted 7 311 Exercised (10) 126 Forfeited (1) 255 Outstanding at end of period 28 211 6.6 $ 3,937 Exercisable at end of period 13 150 5.0 2,579 Vested and expected to vest, end of period 27 210 6.5 3,892
Restricted Share Activity [Table Text Block]	Restricted share activity for the year ended December 31, 2020 is summarized in the table below: (shares in millions) Shares Weighted-Average Nonvested at beginning of period 5 $ 207 Granted 1 303 Vested (2) 187 Nonvested at end of period 4 256
Other Share-Based Compensation Data [Table Text Block]	Other Share-Based Compensation Data (in millions, except per share amounts) For the Years Ended December 31, 2020 2019 2018 Stock Options Weighted-average grant date fair value of shares granted, per share $ 54 $ 46 $ 43 Total intrinsic value of stock options exercised 1,736 1,398 1,431 Restricted Shares Weighted-average grant date fair value of shares granted, per share 303 259 229 Total fair value of restricted shares vested $ 574 $ 545 $ 521 Employee Stock Purchase Plan Number of shares purchased 1 1 2 Share-Based Compensation Items Share-based compensation expense, before tax $ 679 $ 697 $ 638 Share-based compensation expense, net of tax effects 619 641 587 Income tax benefit realized from share-based award exercises 208 201 239 (in millions, except years) December 31, 2020 Unrecognized compensation expense related to share awards $ 805 Weighted-average years to recognize compensation expense 1.4
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 were as follows: For the Years Ended December 31, 2020 2019 2018 Risk-free interest rate 0.2% - 1.4% 1.5% - 2.5% 2.6% - 3.1% Expected volatility 22.2% - 29.5% 19.4% - 21.6% 18.7% - 19.3% Expected dividend yield 1.4% - 1.7% 1.4% - 1.8% 1.3% - 1.5% Forfeiture rate 5.0% 5.0% 5.0% Expected life in years 5.1 5.3 5.6

Commitments and Contingencies_2

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Lessee, Operating Lease, Disclosure [Table Text Block]	As of December 31, 2020, future minimum annual lease payments under all non-cancelable operating leases were as follows: (in millions) Future Minimum Lease Payments 2021 $ 865 2022 775 2023 646 2024 538 2025 441 Thereafter 1,781 Total future minimum lease payments 5,046 Less imputed interest (599) Total $ 4,447

Business Combinations Busines_2

Business Combinations Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	Acquired tangible assets (liabilities) at acquisition date were: (in millions) Cash and cash equivalents $ 715 Accounts receivable and other current assets 735 Property, equipment and other long-term assets 816 Medical costs payable (316) Accounts payable and other current liabilities (861) Other long-term liabilities (817) Total net tangible assets $ 272

Segment Financial Information_2

Segment Financial Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment Financial Information [Table Text Block]	The following table presents the reportable segment financial information: Optum (in millions) UnitedHealthcare OptumHealth OptumInsight OptumRx Optum Eliminations Optum Corporate and Consolidated 2020 Revenues - unaffiliated customers: Premiums $ 191,679 $ 9,799 $ — $ — $ — $ 9,799 $ — $ 201,478 Products — 33 135 33,977 — 34,145 — 34,145 Services 8,464 6,815 3,687 1,050 — 11,552 — 20,016 Total revenues - unaffiliated customers 200,143 16,647 3,822 35,027 — 55,496 — 255,639 Total revenues - affiliated customers — 22,481 6,941 52,420 (1,800) 80,042 (80,042) — Investment and other income 732 680 39 51 — 770 — 1,502 Total revenues $ 200,875 $ 39,808 $ 10,802 $ 87,498 $ (1,800) $ 136,308 $ (80,042) $ 257,141 Earnings from operations $ 12,359 $ 3,434 $ 2,725 $ 3,887 $ — $ 10,046 $ — $ 22,405 Interest expense — — — — — — (1,663) (1,663) Earnings before income taxes $ 12,359 $ 3,434 $ 2,725 $ 3,887 $ — $ 10,046 $ (1,663) $ 20,742 Total assets $ 98,229 $ 52,073 $ 15,425 $ 39,280 $ — $ 106,778 $ (7,718) $ 197,289 Purchases of property, equipment and capitalized software 687 715 461 188 — 1,364 — 2,051 Depreciation and amortization 920 703 670 598 — 1,971 — 2,891 2019 Revenues - unaffiliated customers: Premiums $ 183,783 $ 5,916 $ — $ — $ — $ 5,916 $ — $ 189,699 Products — 31 116 31,450 — 31,597 — 31,597 Services 8,922 5,732 3,630 689 — 10,051 — 18,973 Total revenues - unaffiliated customers 192,705 11,679 3,746 32,139 — 47,564 — 240,269 Total revenues - affiliated customers — 17,966 6,239 42,093 (1,661) 64,637 (64,637) — Investment and other income 1,137 672 21 56 — 749 — 1,886 Total revenues $ 193,842 $ 30,317 $ 10,006 $ 74,288 $ (1,661) $ 112,950 $ (64,637) $ 242,155 Earnings from operations $ 10,326 $ 2,963 $ 2,494 $ 3,902 $ — $ 9,359 $ — $ 19,685 Interest expense — — — — — — (1,704) (1,704) Earnings before income taxes $ 10,326 $ 2,963 $ 2,494 $ 3,902 $ — $ 9,359 $ (1,704) $ 17,981 Total assets $ 88,250 $ 40,444 $ 15,181 $ 36,346 $ — $ 91,971 $ (6,332) $ 173,889 Purchases of property, equipment and capitalized software 841 573 495 162 — 1,230 — 2,071 Depreciation and amortization 926 565 672 557 — 1,794 — 2,720 2018 Revenues - unaffiliated customers: Premiums $ 174,282 $ 3,805 $ — $ — $ — $ 3,805 $ — $ 178,087 Products — 52 111 29,438 — 29,601 — 29,601 Services 8,366 4,925 3,280 612 — 8,817 — 17,183 Total revenues - unaffiliated customers 182,648 8,782 3,391 30,050 — 42,223 — 224,871 Total revenues - affiliated customers — 14,882 5,596 39,440 (1,409) 58,509 (58,509) — Investment and other income 828 481 21 46 — 548 — 1,376 Total revenues $ 183,476 $ 24,145 $ 9,008 $ 69,536 $ (1,409) $ 101,280 $ (58,509) $ 226,247 Earnings from operations $ 9,113 $ 2,430 $ 2,243 $ 3,558 $ — $ 8,231 $ — $ 17,344 Interest expense — — — — — — (1,400) (1,400) Earnings before income taxes $ 9,113 $ 2,430 $ 2,243 $ 3,558 $ — $ 8,231 $ (1,400) $ 15,944 Total assets $ 82,938 $ 29,837 $ 11,039 $ 33,912 $ — $ 74,788 $ (5,505) $ 152,221 Purchases of property, equipment and capitalized software 761 593 517 192 — 1,302 — 2,063 Depreciation and amortization 845 439 654 490 — 1,583 — 2,428

Schedule I (Tables)

Schedule I (Tables)	12 Months Ended
	Dec. 31, 2020
Condensed Financial Statements, Captions [Line Items]
Schedule of Maturities of Long-term Debt [Table Text Block]	Maturities of short-term borrowings and long-term debt for the years ending December 31 are as follows: (in millions) 2021 $ 4,800 2022 3,180 2023 2,290 2024 1,665 2025 2,465 Thereafter 29,349
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Condensed Balance Sheet [Table Text Block]	Condensed Financial Information of Registrant (Parent Company Only) UnitedHealth Group Condensed Balance Sheets (in millions, except per share data) December 31, December 31, Assets Current assets: Cash and cash equivalents $ 258 $ 46 Other current assets 562 787 Total current assets 820 833 Equity in net assets of subsidiaries 107,714 93,467 Long-term notes receivable from subsidiaries 5,021 5,079 Other assets 342 794 Total assets $ 113,897 $ 100,173 Liabilities and shareholders’ equity Current liabilities: Accounts payable and accrued liabilities $ 589 $ 688 Current portion of notes payable to subsidiaries 4,882 750 Short-term borrowings and current maturities of long-term debt 4,465 3,548 Total current liabilities 9,936 4,986 Long-term debt, less current maturities 37,815 35,926 Long-term notes payable to subsidiaries — 1,314 Other liabilities 655 331 Total liabilities 48,406 42,557 Commitments and contingencies (Note 4) Shareholders’ equity: Preferred stock, $0.001 par value -10 shares authorized; no shares issued or outstanding — — Common stock, $0.01 par value - 3,000 shares authorized; 946 and 948 issued and outstanding 10 9 Additional paid-in capital — 7 Retained earnings 69,295 61,178 Accumulated other comprehensive loss (3,814) (3,578) Total UnitedHealth Group shareholders’ equity 65,491 57,616 Total liabilities and shareholders’ equity $ 113,897 $ 100,173
Condensed Statement of Comprehensive Income [Table Text Block]	Condensed Financial Information of Registrant (Parent Company Only) UnitedHealth Group Condensed Statements of Comprehensive Income For the Years Ended December 31, (in millions) 2020 2019 2018 Revenues: Investment and other income $ 194 $ 209 $ 194 Total revenues 194 209 194 Operating costs: Operating costs 27 38 35 Interest expense 1,594 1,580 1,285 Total operating costs 1,621 1,618 1,320 Loss before income taxes (1,427) (1,409) (1,126) Benefit for income taxes 300 293 251 Loss of parent company (1,127) (1,116) (875) Equity in undistributed income of subsidiaries 16,530 14,955 12,861 Net earnings 15,403 13,839 11,986 Other comprehensive (loss) income (236) 582 (1,517) Comprehensive income $ 15,167 $ 14,421 $ 10,469
Condensed Cash Flow Statement [Table Text Block]	Condensed Financial Information of Registrant (Parent Company Only) UnitedHealth Group Condensed Statements of Cash Flows For the Years Ended December 31, (in millions) 2020 2019 2018 Operating activities Cash flows from operating activities $ 8,842 $ 9,275 $ 6,099 Investing activities Issuances of notes to subsidiaries (628) (2,722) (1,420) Repayments of notes to subsidiaries 1,089 2,249 1,419 Cash paid for acquisitions (7,706) (9,645) (4,066) Return of capital to parent company 943 4,497 4,196 Capital contributions to subsidiaries (43) (803) (1,259) Other, net 143 490 4 Cash flows used for investing activities (6,202) (5,934) (1,126) Financing activities Common stock repurchases (4,250) (5,500) (4,500) Proceeds from common stock issuances 1,440 1,037 838 Cash dividends paid (4,584) (3,932) (3,320) Proceeds from (repayments of) short-term borrowings, net 872 300 (201) Proceeds from issuance of long-term debt 4,864 5,444 6,935 Repayments of long-term debt (3,150) (1,750) (2,600) Proceeds (repayments) of notes from subsidiaries 2,818 1,207 (1,127) Other, net (438) (535) (923) Cash flows used for financing activities (2,428) (3,729) (4,898) Increase (decrease) in cash and cash equivalents 212 (388) 75 Cash and cash equivalents, beginning of period 46 434 359 Cash and cash equivalents, end of period $ 258 $ 46 $ 434 Supplemental cash flow disclosures Cash paid for interest $ 1,633 $ 1,506 $ 1,294 Cash paid for income taxes 4,185 2,590 2,379
Schedule of Maturities of Long-term Debt [Table Text Block]	Maturities of short-term borrowings and long-term debt for the years ending December 31 are as follows: (in millions) 2021 $ 4,446 2022 3,015 2023 2,125 2024 1,500 2025 2,300 Thereafter 29,177

Basis of Presentation, Uses o_4

Basis of Presentation, Uses of Estimates and Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Jan. 01, 2020	Dec. 31, 2019USD ($)
Accounts Receivable, after Allowance for Credit Loss, Current	$ 12,870		$ 11,822
Other current receivables	12,534		9,640
Goodwill, Impairment Loss	0
Impairment of Intangible Assets (Excluding Goodwill)	0
Other Liabilities, Current	$ 20,392		14,595
Number Of Days Notice Required To Cancel Health Insurance Contract	30
Healthcare Sector [Member]
Health Insurance Industry Tax	$ 3,000
Other Current Liabilities [Member]
Health savings account deposits	$ 10,200		8,300
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Share-based Compensation Arrangement by Share-based Payment Plan Award, Options, Award Exercisable Period	10 years
Employee Stock Purchase Plan (ESPP) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date	10.00%
Accounting Standards Update 2016-13
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]		true
Health Insurance Product Line [Member]
Short-duration Insurance Contracts, Historical Claims Duration, First 90 Days	0.90
Products and services [Member]
Accounts Receivable, after Allowance for Credit Loss, Current	$ 5,300		4,300
Pharmaceutical Manufacturer Rebates Receivable [Member]
Other current receivables	6,300		4,700
Medicare Part D Receivables [Member]
Other current receivables	$ 2,900		$ 2,300

Basis of Presentation, Uses o_5

Basis of Presentation, Uses of Estimates and Significant Accounting Policies Useful lives for property, equipment and capitalized software (Details)	12 Months Ended
	Dec. 31, 2020
Furniture, Fixtures and equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	3 years
Furniture, Fixtures and equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	10 years
Buildings [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	35 years
Buildings [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	40 years
Capitalized software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	3 years
Capitalized software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life	5 years

Basis of Presentation, Uses o_6

Basis of Presentation, Uses of Estimates and Significant Accounting Policies Redeemable Noncontrolling Interests (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Noncontrolling Interest [Line Items]
Redeemable noncontrolling interest, beginning of period	$ 1,726
Acquisitions	40	$ 87	$ 521
Distributions	(277)	(279)	(228)
Fair value and other adjustments	197	316	163
Redeemable Noncontrolling Interest, end of period	2,211	1,726
Redeemable Noncontrolling Interests [Member]
Noncontrolling Interest [Line Items]
Redeemable noncontrolling interest, beginning of period	1,726	1,908
Net earnings	112	115
Acquisitions	321	90
Redemptions	0	(618)
Distributions	(149)	(69)
Fair value and other adjustments	201	300
Redeemable Noncontrolling Interest, end of period	$ 2,211	$ 1,726	$ 1,908

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Millions	Dec. 31, 2020USD ($)positions	Dec. 31, 2019USD ($)
Investment [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | positions	2,000
Total number of security positions	36,000
Equity Securities, FV-NI and without Readily Determinable Fair Value	$ 2,300	$ 2,000
Equity Method Investments	$ 1,300	$ 1,400

Investments (Short-Term and Lon

Investments (Short-Term and Long-Term Investments) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 38,079	$ 35,328
Securities, Available for sale Debt Securities, Gross Unrealized Gains	1,771	795
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(22)	(29)
Debt Securities, Available-for-sale	39,828	36,094
Held-to-maturity securities, Amortized Cost	638	972
Securities, Held to maturity, Unrecognized Holding Gain	9	4
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(1)
Debt Securities, Held-to-maturity, Fair Value	647	975
Total investments, Amortized Cost	38,717	36,300
Total investments, Gross Unrealized Gains	1,780	799
Total investments, Gross Unrealized Losses	(22)	(30)
Investments, Fair Value Disclosure	40,475	37,069
Debt Securities - available-for-sale
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale	39,828	36,094
U.S. Government and Agency Obligations [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	3,335	3,502
Securities, Available for sale Debt Securities, Gross Unrealized Gains	133	55
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(3)	(4)
Debt Securities, Available-for-sale	3,465	3,553
Held-to-maturity securities, Amortized Cost	420	402
Securities, Held to maturity, Unrecognized Holding Gain	6	2
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Debt Securities, Held-to-maturity, Fair Value	426	404
State and Municipal Obligations [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	6,893	5,680
Securities, Available for sale Debt Securities, Gross Unrealized Gains	435	251
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	(5)
Debt Securities, Available-for-sale	7,328	5,926
Held-to-maturity securities, Amortized Cost	31	32
Securities, Held to maturity, Unrecognized Holding Gain	2	2
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Debt Securities, Held-to-maturity, Fair Value	33	34
Corporate Obligations [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	18,886	17,910
Securities, Available for sale Debt Securities, Gross Unrealized Gains	863	343
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(12)	(11)
Debt Securities, Available-for-sale	19,737	18,242
Held-to-maturity securities, Amortized Cost	187	538
Securities, Held to maturity, Unrecognized Holding Gain	1	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(1)
Debt Securities, Held-to-maturity, Fair Value	188	537
U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	6,849	6,425
Securities, Available for sale Debt Securities, Gross Unrealized Gains	245	109
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(3)	(6)
Debt Securities, Available-for-sale	7,091	6,528
Non-U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	2,116	1,811
Securities, Available for sale Debt Securities, Gross Unrealized Gains	95	37
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(4)	(3)
Debt Securities, Available-for-sale	$ 2,207	$ 1,845

Investments (Amortized Cost and

Investments (Amortized Cost and Fair Value of Available-for-Sale Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Schedule of Investments [Line Items]
Due in one year or less, Amortized Cost	$ 2,951
Due after one year through five years, Amortized Cost	11,638
Due after five years through ten years, Amortized Cost	10,212
Due after ten years, Amortized Cost	4,313
Total debt securities - available-for-sale, Amortized Cost	38,079	$ 35,328
Due in one year or less, Fair Value	2,966
Due after one year through five years, Fair Value	12,088
Due after five years through ten years, Fair Value	10,931
Due after ten years, Fair Value	4,545
Debt Securities, Available-for-sale	39,828	36,094
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost	348
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value	349
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	241
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	245
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	27
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	29
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Amortized Cost	22
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	24
Debt Securities, Held-to-maturity	638	972
Debt Securities, Held-to-maturity, Fair Value	647	975
U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Mortgage-backed securities, Amortized Cost	6,849
Total debt securities - available-for-sale, Amortized Cost	6,849	6,425
Debt Securities, Available-for-sale	7,091	6,528
Mortgage-backed securities, Fair Value	7,091
Non-U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Mortgage-backed securities, Amortized Cost	2,116
Total debt securities - available-for-sale, Amortized Cost	2,116	1,811
Debt Securities, Available-for-sale	2,207	$ 1,845
Mortgage-backed securities, Fair Value	$ 2,207

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 ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Securities - available-for-sale
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	$ 2,415	$ 4,022
Less Than 12 Months, Gross Unrealized Losses	(16)	(22)
Greater Than 12 Months, Fair Value	549	1,073
Greater Than 12 Months, Gross Unrealized Losses	(6)	(7)
Total, Fair Value	2,964	5,095
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(22)	(29)
U.S. Government and Agency Obligations [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	346	616
Less Than 12 Months, Gross Unrealized Losses	(3)	(4)
Greater Than 12 Months, Fair Value	0	0
Greater Than 12 Months, Gross Unrealized Losses	0	0
Total, Fair Value	346	616
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(3)	(4)
State and Municipal Obligations [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value		440
Less Than 12 Months, Gross Unrealized Losses		(5)
Greater Than 12 Months, Fair Value		0
Greater Than 12 Months, Gross Unrealized Losses		0
Total, Fair Value		440
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		(5)
Corporate Obligations [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	1,273	1,903
Less Than 12 Months, Gross Unrealized Losses	(9)	(7)
Greater Than 12 Months, Fair Value	456	740
Greater Than 12 Months, Gross Unrealized Losses	(3)	(4)
Total, Fair Value	1,729	2,643
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(12)	(11)
U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	601	657
Less Than 12 Months, Gross Unrealized Losses	(3)	(3)
Greater Than 12 Months, Fair Value	0	333
Greater Than 12 Months, Gross Unrealized Losses	0	(3)
Total, Fair Value	601	990
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(3)	(6)
Non-U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	195	406
Less Than 12 Months, Gross Unrealized Losses	(1)	(3)
Greater Than 12 Months, Fair Value	93	0
Greater Than 12 Months, Gross Unrealized Losses	(3)	0
Total, Fair Value	288	406
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (4)	$ (3)

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value [Line Items]
Transfers Into Level 3	$ 0	$ 0
Transfers out of Level 3	0	0
Fair Value, Nonrecurring [Member]
Fair Value [Line Items]
Significant fair value adjustments for assets and liabilities measured on a nonrecurring basis	$ 0	$ 0

Fair Value (Financial Assets an

Fair Value (Financial Assets and Liabilities, Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 16,921	$ 10,985
Debt Securities, Available-for-sale	39,828	36,094
Equity Securities, FV-NI	1,828	1,756
Assets under management	4,076	3,076
Assets, Fair Value Disclosure	62,653	51,911
Debt Securities - available-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	39,828	36,094
U.S. Government and Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	3,465	3,553
State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	7,328	5,926
Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	19,737	18,242
U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	7,091	6,528
Non-U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	2,207	1,845
Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	16,841	10,837
Equity Securities, FV-NI	1,795	1,734
Assets under management	1,774	1,123
Assets, Fair Value Disclosure	23,676	17,133
Quoted Prices in Active Markets (Level 1) [Member] | Debt Securities - available-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	3,266	3,439
Quoted Prices in Active Markets (Level 1) [Member] | U.S. Government and Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	3,241	3,369
Quoted Prices in Active Markets (Level 1) [Member] | State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Quoted Prices in Active Markets (Level 1) [Member] | Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	25	70
Quoted Prices in Active Markets (Level 1) [Member] | U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Quoted Prices in Active Markets (Level 1) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	80	148
Equity Securities, FV-NI	33	22
Assets under management	2,250	1,918
Assets, Fair Value Disclosure	38,637	34,494
Other Observable Inputs (Level 2) [Member] | Debt Securities - available-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	36,274	32,406
Other Observable Inputs (Level 2) [Member] | U.S. Government and Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	224	184
Other Observable Inputs (Level 2) [Member] | State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	7,328	5,926
Other Observable Inputs (Level 2) [Member] | Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	19,424	17,923
Other Observable Inputs (Level 2) [Member] | U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	7,091	6,528
Other Observable Inputs (Level 2) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	2,207	1,845
Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Equity Securities, FV-NI	0	0
Assets under management	52	35
Assets, Fair Value Disclosure	340	284
Unobservable Inputs (Level 3) [Member] | Debt Securities - available-for-sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	288	249
Unobservable Inputs (Level 3) [Member] | U.S. Government and Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Unobservable Inputs (Level 3) [Member] | State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Unobservable Inputs (Level 3) [Member] | Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	288	249
Unobservable Inputs (Level 3) [Member] | U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Unobservable Inputs (Level 3) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	$ 0	$ 0

Fair Value (Financial Assets _2

Fair Value (Financial Assets and Liabilities, Not Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	$ 647	$ 975
Debt Securities, Held-to-maturity	638	972
Debt and other financing obligations, carrying value	42,280	39,474
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	647	975
Fair Value, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	466	541
Fair Value, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	108	181
Fair Value, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	73	253
Long-term debt and other financing obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations, carrying value	42,171	40,278
Long-term debt and other financing obligations [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations	51,254	45,078
Long-term debt and other financing obligations [Member] | Fair Value, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations	0	0
Long-term debt and other financing obligations [Member] | Fair Value, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations	51,254	45,078
Long-term debt and other financing obligations [Member] | Fair Value, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations	$ 0	$ 0

Property, Plant, and Capitali_3

Property, Plant, and Capitalized Software (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Depreciation	$ 997	$ 995	$ 924
Capitalized Computer Software, Amortization	$ 814	$ 721	$ 606

Property, Plant, and Capitali_4

Property, Plant, and Capitalized Software Property Plant and Equipment Table (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Land and improvements	$ 533	$ 589
Buildings and improvements	4,759	4,705
Computer equipment	1,767	2,015
Furniture and fixtures	1,787	1,752
Less accumulated depreciation	(3,364)	(3,328)
Property and equipment, net	5,482	5,733
Capitalized software	5,010	4,638
Less accumulated amortization	(1,866)	(1,667)
Capitalized software, net	3,144	2,971
Total property, equipment and capitalized software, net	$ 8,626	$ 8,704

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 1,100	$ 1,000	$ 898

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets Changes in the Carrying Amount of Goodwill by Reporting Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 65,659	$ 58,910
Acquisitions	6,379	6,944
Foreign currency effects and adjustments, net	(701)	(195)
Goodwill, Ending Balance	71,337	65,659
UnitedHealthcare
Goodwill [Line Items]
Goodwill, Beginning Balance	27,228	26,400
Acquisitions	1,180	1,022
Foreign currency effects and adjustments, net	(623)	(194)
Goodwill, Ending Balance	27,785	27,228
OptumHealth
Goodwill [Line Items]
Goodwill, Beginning Balance	15,342	11,947
Acquisitions	4,500	3,395
Foreign currency effects and adjustments, net	2	0
Goodwill, Ending Balance	19,844	15,342
OptumInsight
Goodwill [Line Items]
Goodwill, Beginning Balance	8,292	5,772
Acquisitions	0	2,521
Foreign currency effects and adjustments, net	(119)	(1)
Goodwill, Ending Balance	8,173	8,292
OptumRx
Goodwill [Line Items]
Goodwill, Beginning Balance	14,797	14,791
Acquisitions	699	6
Foreign currency effects and adjustments, net	39	0
Goodwill, Ending Balance	$ 15,535	$ 14,797

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets Gross carrying value, accumulated amortization and net carrying value of intangible assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 16,311	$ 15,421
Finite-Lived Intangible Assets, Accumulated Amortization	(5,455)	(5,072)
Intangible Assets, Net (Excluding Goodwill)	10,856	10,349
Customer-Related Intangible Assets [Member]
Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	13,428	12,968
Finite-Lived Intangible Assets, Accumulated Amortization	(4,575)	(4,319)
Intangible Assets, Net (Excluding Goodwill)	8,853	8,649
Trademarks and Technology [Member]
Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	1,597	1,186
Finite-Lived Intangible Assets, Accumulated Amortization	(624)	(525)
Intangible Assets, Net (Excluding Goodwill)	973	661
Trademarks and Trade Names [Member]
Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	680	726
Finite-Lived Intangible Assets, Accumulated Amortization	0	0
Intangible Assets, Net (Excluding Goodwill)	680	726
Other Intangible Assets [Member]
Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	606	541
Finite-Lived Intangible Assets, Accumulated Amortization	(256)	(228)
Intangible Assets, Net (Excluding Goodwill)	$ 350	$ 313

Goodwill and Intangible Asset_6

Goodwill and Intangible Assets Weighted-average useful lives assigned to finite-lived intangible assets acquired in business combinations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 1,722	$ 2,032
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	11 years	13 years
Customer-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 1,113	$ 1,750
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	11 years	13 years
Trademarks and Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 514	$ 163
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years	5 years
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets Acquired	$ 95	$ 119
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years	11 years

Goodwill and Intangible Asset_7

Goodwill and Intangible Assets Amortization Expense relating to Intangible Assets (Details) $ in Millions	Dec. 31, 2020USD ($)
Finite-Lived Intangible Assets [Line Items]
2021	$ 1,105
2022	998
2023	933
2024	887
2025	$ 850

Medical Costs Payable (Narrativ

Medical Costs Payable (Narrative) (Details) - USD ($) $ in Billions	Dec. 31, 2020	Dec. 31, 2019
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred but Not Reported (IBNR) Claims, Amount	$ 14.8	$ 13.8

Medical Costs Payable Rollforwa

Medical Costs Payable Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Medical costs payable, beginning of period	$ 21,690	$ 19,891	$ 17,871
Acquisitions	316	679	339
Reported medical costs:
Current year	160,276	157,020	145,723
Prior years	(880)	(580)	(320)
Total reported medical costs	159,396	156,440	145,403
Medical payments:
Payments for current year	(139,974)	(137,155)	(127,155)
Payments for prior years	(19,556)	(18,165)	(16,567)
Total medical payments	(159,530)	(155,320)	(143,722)
Medical costs payable, end of period	$ 21,872	$ 21,690	$ 19,891

Medical Costs Payable, Incurred

Medical Costs Payable, Incurred and Paid Medical Cost Development (Details) - Health Insurance Product Line [Member] - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Net Incurred Medical Costs	$ 316,493
Net Cumulative Medical Payments	(295,124)
Net remaining outstanding liabilities prior to 2019	503
Total Medical costs payable	21,872
Short-duration Insurance Contracts, Accident Year 2019 [Member]
Net Incurred Medical Costs	156,217	$ 157,020
Net Cumulative Medical Payments	(155,150)	$ (137,155)
Short-duration Insurance Contracts, Accident Year 2020 [Member]
Net Incurred Medical Costs	160,276
Net Cumulative Medical Payments	$ (139,974)

Short-Term Borrowings and Lon_3

Short-Term Borrowings and Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commercial Paper [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	0.20%
Minimum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period	0.80%
Maximum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period	1.00%
Five Year $4.4 Billion Credit Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	$ 0
Line of Credit, Credit Facility, Maximum Borrowing Capacity	$ 4,400
Maturity Period, Line of Credit	5 years
Three Year $4.4 Billion Credit Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	$ 0
Line of Credit, Credit Facility, Maximum Borrowing Capacity	$ 4,400
Maturity Period, Line of Credit	3 years
364 Day $3.8 Billion Credit Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	$ 0
Line of Credit, Credit Facility, Maximum Borrowing Capacity	$ 3,800
Maturity Period, Line of Credit	364 days
Subsidiaries [Member]
Debt Instrument [Line Items]
Other Long-term Debt	$ 1,200	$ 1,200
Other Long-term Debt, Current	$ 354	$ 322

Short-Term Borrowings and Lon_4

Short-Term Borrowings and Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Par Value	$ 42,563	$ 39,817
Carrying Value, Combined Amount	42,280	39,474
Fair Value	51,301	44,234
Commercial Paper [Member]
Debt Instrument [Line Items]
Par Value	1,296	400
Commercial Paper	1,296	400
Fair Value	$ 1,296	400
2.700% notes Due July 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.70%
Par Value	$ 0	1,500
Carrying Value, Current	0	1,499
Fair Value	0	1,506
Floating rate notes due October 2020 [Member]
Debt Instrument [Line Items]
Par Value	0	300
Carrying Value, Current	0	300
Fair Value	$ 0	300
3.875% notes Due October 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.875%
Par Value	$ 0	450
Carrying Value, Current	0	450
Fair Value	$ 0	455
1.950% notes due October 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.95%
Par Value	$ 0	900
Carrying Value, Current	0	899
Fair Value	$ 0	900
4.700% Notes Due February 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.70%
Par Value	$ 400	400
Carrying Value, Noncurrent		403
Carrying Value, Current	400
Fair Value	$ 401	410
2.125% notes due March 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.125%
Par Value	$ 750	750
Carrying Value, Noncurrent		749
Carrying Value, Current	750
Fair Value	753	753
Floating rate notes due June 2021 [Member]
Debt Instrument [Line Items]
Par Value	350	350
Carrying Value, Noncurrent		349
Carrying Value, Current	350
Fair Value	$ 350	350
3.150% notes due June 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.15%
Par Value	$ 400	400
Carrying Value, Noncurrent		399
Carrying Value, Current	400
Fair Value	$ 405	407
3.375% Notes Due November 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.375%
Par Value	$ 500	500
Carrying Value, Noncurrent		501
Carrying Value, Current	507
Fair Value	$ 509	512
2.875% Notes Due December 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.875%
Par Value	$ 750	750
Carrying Value, Noncurrent		753
Carrying Value, Current	762
Fair Value	$ 768	765
2.875% Notes Due March 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.875%
Par Value	$ 1,100	1,100
Carrying Value, Noncurrent	1,113	1,087
Fair Value	$ 1,127	1,121
3.350% Notes Due July 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.35%
Par Value	$ 1,000	1,000
Carrying Value, Noncurrent	999	998
Fair Value	$ 1,048	1,036
2.375% notes due October 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.375%
Par Value	$ 900	900
Carrying Value, Noncurrent	897	896
Fair Value	$ 935	911
0.000% Notes Due November 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.00%
Par Value	$ 15	15
Carrying Value, Noncurrent	14	13
Fair Value	$ 14	14
2.750% Notes Due February 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.75%
Par Value	$ 625	625
Carrying Value, Noncurrent	644	624
Fair Value	$ 654	638
2.875% Notes Due March 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.875%
Par Value	$ 750	750
Carrying Value, Noncurrent	789	770
Fair Value	$ 793	770
3.500% notes due June 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.50%
Par Value	$ 750	750
Carrying Value, Noncurrent	748	747
Fair Value	$ 809	786
3.500% notes due February 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.50%
Par Value	$ 750	750
Carrying Value, Noncurrent	747	746
Fair Value	$ 821	792
2.375% notes due August 2024 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.375%
Par Value	$ 750	750
Carrying Value, Noncurrent	747	747
Fair Value	$ 799	760
3.750% Notes Due July 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.75%
Par Value	$ 2,000	2,000
Carrying Value, Noncurrent	1,992	1,990
Fair Value	$ 2,279	2,161
3.700% notes due December 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.70%
Par Value	$ 300	300
Carrying Value, Noncurrent	298	298
Fair Value	$ 344	325
1.250% notes due January 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.25%
Par Value	$ 500	0
Carrying Value, Noncurrent	496	0
Fair Value	$ 515	0
3.100% notes due March 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.10%
Par Value	$ 1,000	1,000
Carrying Value, Noncurrent	997	996
Fair Value	$ 1,121	1,048
3.450% notes due January 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.45%
Par Value	$ 750	750
Carrying Value, Noncurrent	747	746
Fair Value	$ 859	804
3.375% notes due April 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.375%
Par Value	$ 625	625
Carrying Value, Noncurrent	620	620
Fair Value	$ 714	667
2.950% notes due October 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.95%
Par Value	$ 950	950
Carrying Value, Noncurrent	940	939
Fair Value	$ 1,067	988
3.850% notes due June 2028 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.85%
Par Value	$ 1,150	1,150
Carrying Value, Noncurrent	1,143	1,142
Fair Value	$ 1,367	1,269
3.875% notes due December 2028 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.875%
Par Value	$ 850	850
Carrying Value, Noncurrent	844	843
Fair Value	$ 1,019	941
2.875% notes due August 2029 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.875%
Par Value	$ 1,000	1,000
Carrying Value, Noncurrent	1,086	993
Fair Value	$ 1,137	1,029
2.000% notes due May 2030 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.00%
Par Value	$ 1,250	0
Carrying Value, Noncurrent	1,234	0
Fair Value	$ 1,326	0
4.625% notes Due July 2035 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.625%
Par Value	$ 1,000	1,000
Carrying Value, Noncurrent	992	992
Fair Value	$ 1,340	1,215
5.800% notes Due March 2036 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.80%
Par Value	$ 850	850
Carrying Value, Noncurrent	839	838
Fair Value	$ 1,271	1,129
6.500% notes Due June 2037 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.50%
Par Value	$ 500	500
Carrying Value, Noncurrent	492	492
Fair Value	$ 800	712
6.625% notes due November 2037 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.625%
Par Value	$ 650	650
Carrying Value, Noncurrent	641	641
Fair Value	$ 1,044	940
6.875% notes Due February 2038 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	6.875%
Par Value	$ 1,100	1,100
Carrying Value, Noncurrent	1,077	1,076
Fair Value	$ 1,802	1,631
3.500% notes due August 2039 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.50%
Par Value	$ 1,250	1,250
Carrying Value, Noncurrent	1,241	1,241
Fair Value	$ 1,487	1,313
2.750% notes due May 2040 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.75%
Par Value	$ 1,000	0
Carrying Value, Noncurrent	964	0
Fair Value	$ 1,085	0
5.700% notes Due October 2040 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.70%
Par Value	$ 300	300
Carrying Value, Noncurrent	296	296
Fair Value	$ 451	396
5.950% notes Due Februrary 2041 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.95%
Par Value	$ 350	350
Carrying Value, Noncurrent	346	345
Fair Value	$ 540	475
4.625% notes Due November 2041 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.625%
Par Value	$ 600	600
Carrying Value, Noncurrent	589	589
Fair Value	$ 820	716
4.375% notes Due March 2042 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.375%
Par Value	$ 502	502
Carrying Value, Noncurrent	485	484
Fair Value	$ 661	580
3.950% notes Due October 2042 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.95%
Par Value	$ 625	625
Carrying Value, Noncurrent	608	607
Fair Value	$ 790	688
4.250% notes Due March 2043 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.25%
Par Value	$ 750	750
Carrying Value, Noncurrent	735	735
Fair Value	$ 982	856
4.750% notes Due July 2045 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.75%
Par Value	$ 2,000	2,000
Carrying Value, Noncurrent	1,974	1,973
Fair Value	$ 2,814	2,463
4.200% notes due January 2047 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.20%
Par Value	$ 750	750
Carrying Value, Noncurrent	738	738
Fair Value	$ 991	861
4.250% notes due April 2047 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.25%
Par Value	$ 725	725
Carrying Value, Noncurrent	717	717
Fair Value	$ 963	839
3.750% notes due October 2047 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.75%
Par Value	$ 950	950
Carrying Value, Noncurrent	934	934
Fair Value	$ 1,180	1,023
4.250% notes due June 2048 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.25%
Par Value	$ 1,350	1,350
Carrying Value, Noncurrent	1,330	1,330
Fair Value	$ 1,803	1,569
4.450% notes due December 2048 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.45%
Par Value	$ 1,100	1,100
Carrying Value, Noncurrent	1,086	1,086
Fair Value	$ 1,517	1,316
3.700% notes due August 2049 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.70%
Par Value	$ 1,250	1,250
Carrying Value, Noncurrent	1,235	1,235
Fair Value	$ 1,567	1,344
2.900% notes due May 2050 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.90%
Par Value	$ 1,250	0
Carrying Value, Noncurrent	1,208	0
Fair Value	$ 1,384	0
3.875% notes due August 2059 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.875%
Par Value	$ 1,250	1,250
Carrying Value, Noncurrent	1,228	1,228
Fair Value	$ 1,618	1,350
3.125% notes due May 2060 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.125%
Par Value	$ 1,000	0
Carrying Value, Noncurrent	965	0
Fair Value	$ 1,161	$ 0

Short-Term Borrowings and Lon_5

Short-Term Borrowings and Long-Term Debt Maturities of commercial paper and long-term debt (Details) $ in Millions	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
2021	$ 4,800
2022	3,180
2023	2,290
2024	1,665
2025	2,465
Thereafter	$ 29,349

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	$ 52	$ 19	$ 6
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	128	$ 76
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	39
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 1,000
Federal [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Expiration Date	Jan. 1, 2023
Open Tax Year	2017
Federal [Member] | Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2037
Open Tax Year	2020
State [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Expiration Date	Jan. 1, 2021
Open Tax Year	2013
State [Member] | Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Expiration Date	Dec. 31, 2040
Open Tax Year	2020
Non-U.S [Member] | Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Open Tax Year	2015
Non-U.S [Member] | Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Open Tax Year	2020
Finite-lived NOL carryforwards [Member] | Federal [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards	$ 100
Indefinite NOL carryforwards [Member] | Federal [Member]
Income Tax Contingency [Line Items]
Operating Loss Carryforwards	$ 309

Income Taxes Reconciliation of

Income Taxes Reconciliation of Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current Provision:
Federal	$ 4,098	$ 2,629	$ 2,897
State and local	392	319	219
Foreign	491	564	404
Total current provision	4,981	3,512	3,520
Deferred (benefit) provision	(8)	230	42
Total provision for income taxes	$ 4,973	$ 3,742	$ 3,562

Income Tax Reconciliation of th

Income Tax Reconciliation of the tax provision at the U.S. Federal Statutory Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Tax provision at the U.S. federal statutory rate, Amount	$ 4,356	$ 3,776	$ 3,348
Tax provision at the U.S. federal statutory rate, Percent	21.00%	21.00%	21.00%
State income taxes, net of federal benefit, Amount	$ 315	$ 271	$ 168
State income taxes, net of federal benefit, Percent	1.50%	1.50%	1.00%
Share-based awards - excess tax benefit, Amount	$ (130)	$ (132)	$ (161)
Share-based awards - excess tax benefit, Percent	(0.60%)	(0.70%)	(1.00%)
Non-deductible compensation, Amount	$ 134	$ 119	$ 117
Non-deductible compensation, Percent	0.70%	0.70%	0.70%
Health insurance tax, Amount	$ 626	$ 0	$ 552
Health insurance tax, Percent	3.00%	0.00%	3.50%
Foreign rate differential, Amount	$ (164)	$ (214)	$ (203)
Foreign rate differential, Percent	(0.80%)	(1.20%)	(1.30%)
Other, net, Amount	$ (164)	$ (78)	$ (259)
Other, net, Percent	(0.80%)	(0.50%)	(1.60%)
Total provision for income taxes	$ 4,973	$ 3,742	$ 3,562
Provision for income taxes, Percent	24.00%	20.80%	22.30%

Income Taxes Components of Defe

Income Taxes Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax assets:
Accrued expenses and allowances	$ 815	$ 654
U.S. federal and state net operating loss carryforwards	276	260
Share-based compensation	98	97
Nondeductible liabilities	252	184
Non-U.S. tax loss carryforwards	340	420
Lease liability	1,200	892
Other-domestic	126	179
Other-non-U.S.	454	329
Subtotal	3,561	3,015
Less: valuation allowances	(170)	(147)
Total deferred income tax assets	3,391	2,868
Deferred income tax liabilities:
U.S. federal and state intangible assets	(2,588)	(2,370)
Non-U.S. goodwill and intangible assets	(606)	(735)
Capitalized software	(731)	(683)
Depreciation and amortization	(346)	(301)
Prepaid expenses	(216)	(172)
Outside basis in partnerships	(342)	(317)
Lease right-of-use asset	(1,179)	(887)
Net unrealized gains on investments	(400)	(177)
Other-non-U.S.	(350)	(219)
Total deferred income tax liabilities	(6,758)	(5,861)
Net deferred income tax liabilities	$ (3,367)	$ (2,993)

Income Taxes Reconciliation o_2

Income Taxes Reconciliation of the beginning and ending amount of unrecognized tax benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
Gross unrecognized tax benefits, beginning of period	$ 1,423	$ 1,056	$ 598
Current year tax positions	416	512	487
Prior year tax positions, gross increases	120	2	87
Prior year tax positions, gross decreases	(130)	(96)	(84)
Settlements	0	(46)	(20)
Statute of limitations lapses	0	(5)	(12)
Gross unrecognized tax benefits, end of period	$ 1,829	$ 1,423	$ 1,056

Shareholders' Equity (Narrative

Shareholders' Equity (Narrative) (Details) - USD ($) shares in Millions, $ in Billions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jun. 01, 2018
Shareholders' Equity Disclosure [Line Items]
Cash Dividends Paid to Parent, Consolidated Subsidiaries	$ 8.3	$ 5.6
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	29.6
Statutory Accounting Practices, Statutory Capital and Surplus Required	11.9
Stock Repurchase Program, Number of Shares Authorized to be Repurchased			100
Extraordinary Dividends [Member]
Shareholders' Equity Disclosure [Line Items]
Cash Dividends Paid to Parent, Consolidated Subsidiaries	$ 4.2	$ 1.3

Shareholders' Equity Share Repu

Shareholders' Equity Share Repurchases (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Common shares repurchases, shares	14,000,000	22,000,000
Common share repurchases, average price per share	$ 300.58	$ 245.97
Common share repurchases	$ 4,250	$ 5,500	$ 4,500
Board authorized shares remaining	58,000,000	72,000,000

Shareholders' Equity Dividends

Shareholders' Equity Dividends (Details) - USD ($) $ / shares in Units, $ in Millions	Dec. 15, 2020	Sep. 22, 2020	Jun. 30, 2020	Mar. 24, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Cash dividends per common share	$ 1.25	$ 1.25	$ 1.25	$ 1.08	$ 4.83	$ 4.14	$ 3.45
Payments of Ordinary Dividends, Common Stock	$ 1,184	$ 1,188	$ 1,188	$ 1,024	$ 4,584	$ 3,932	$ 3,320

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended
	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		71
Deferred Compensation, Recorded Liability		$ 1,600	$ 1,400
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	48
Employee Stock Purchase Plan (ESPP) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		4

Share-Based Compensation (Stock

Share-Based Compensation (Stock Option Activity) (Details) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at the beginning of the period | shares	32
Granted | shares	7
Exercised | shares	(10)
Forfeitures | shares	(1)
Outstanding at the end of the period | shares	28
Exercisable at end of period | shares	13
Vested and expected to vest, end of period | shares	27
Outstanding at beginning of period, Weighted-Average Exercise Price | $ / shares	$ 166
Granted, Weighted-Average Exercise Price | $ / shares	311
Exercised, Weighted-Average Exercise Price | $ / shares	126
Forfeitures, Weighted Average Exercise Price | $ / shares	255
Outstanding at end of period, Weighted-Average Exercise Price | $ / shares	211
Exercisable at end of period, Weighted-Average Exercise Price | $ / shares	150
Vested and expected to vest end of period, Weighted-Average Exercise Price | $ / shares	$ 210
Outstanding at end of period, Weighted Average Remaining Contractual Term (in years)	6 years 6 months 30 days
Exercisable at end of period, Weighted Average Remaining Contractual Term (in years)	5 years
Vested and expected to vest end of period, Weighted Average Remaining Contractual Term (in years)	6 years 6 months
Outstanding at end of period, Aggregate Intrinsic Value | $	$ 3,937
Exercisable at end of period, Aggregate Intrinsic Value | $	2,579
Vested and expected to vest end of period, Aggregate Intrinsic Value | $	$ 3,892

Share-Based Compensation (Restr

Share-Based Compensation (Restricted Share Activity) (Details) - Restricted Stock [Member] shares in Millions	12 Months Ended
	Dec. 31, 2020$ / sharesshares
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	5
Granted | shares	1
Vested | shares	(2)
Nonvested at end of period | shares	4
Nonvested at beginning of period, Weighted-Average Grant Date Fair Value per Share | $ / shares	$ 207
Weighted-average grant date fair value per share | $ / shares	303
Vested, Weighted Average Grant Date Fair Value per share | $ / shares	187
Nonvested at end of period, Weighted-Average Grant Date Fair Value per Share | $ / shares	$ 256

Share-Based Compensation Other

Share-Based Compensation Other Share-Based Compensation Data (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before tax	$ 679	$ 697	$ 638
Share-based compensation expense, net of tax effects	619	641	587
Income tax benefit realized from share-based award exercises	208	$ 201	$ 239
Unrecognized compensation expense related to share awards	$ 805
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 4 months 25 days
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of shares granted, per share	$ 54	$ 46	$ 43
Total intrinsic value of stock options exercised	$ 1,736	$ 1,398	$ 1,431
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value per share	$ 303	$ 259	$ 229
Total fair value of restricted shares vested	$ 574	$ 545	$ 521
Employee Stock Purchase Plan (ESPP) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares purchased	1	1	2

Share-Based Compensation (Share

Share-Based Compensation (Share-Based Compensation Principal Fair Value Assumptions) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeiture rate	5.00%	5.00%	5.00%
Expected Life in years	5 years 1 month 7 days	5 years 3 months 18 days	5 years 7 months 9 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	6 years 6 months 30 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	6 years 6 months
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	0.20%	1.50%	2.60%
Expected Volatility	22.20%	19.40%	18.70%
Expected dividend yield	1.40%	1.40%	1.30%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.40%	2.50%	3.10%
Expected Volatility	29.50%	21.60%	19.30%
Expected dividend yield	1.70%	1.80%	1.50%

Commitments and Contingencies_3

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Operating Lease, Cost				$ 1,100	$ 1,000	$ 751
Operating Lease, Payments				$ 865	$ 746
Operating Lease, Weighted Average Remaining Lease Term		8 years 8 months 12 days		8 years 8 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent		3.00%		3.00%
Undrawn Letters Of Credit		$ 134		$ 134
Surety Bonds Outstanding		$ 1,200		$ 1,200
Other Commitments, Description		In the fourth quarter of 2020, the Company entered into agreements to acquire multiple companies in the health care sector, which are expected to close in the first half of 2021, subject to regulatory approval and other customary closing conditions.
Subsequent Event [Member]
Loss Contingencies [Line Items]
Subsequent Event, Description	Additionally, in January 2021, the Company entered into agreements to purchase multiple companies in the health care sector, most notably, Change Healthcare (NASDAQ: CHNG). This acquisition is expected to close in the second half of 2021, subject to Change Healthcare shareholders’ approval, regulatory approvals and other customary closing conditions.
Payments to be made to Acquire Businesses Net			$ 13,000

Commitments and Contingencies F

Commitments and Contingencies Future Lease Payments (Details) $ in Millions	Dec. 31, 2020USD ($)
Operating Leased Assets [Line Items]
2021	$ 865
2022	775
2023	646
2024	538
2025	441
Thereafter	1,781
Total future minimum lease payments	5,046
Less imputed interest	(599)
Commitments
Operating Leased Assets [Line Items]
Total	$ 4,447

Business Combinations Acquired

Business Combinations Acquired Assets and Liabilities (Details) $ in Millions	Dec. 31, 2020USD ($)
Business Acquisition [Line Items]
Cash and cash equivalents	$ 715
Accounts receivable and other current assets	735
Property, equipment and other long-term assets	816
Medical costs payable	(316)
Accounts payable and other current liabilities	(861)
Other long-term liabilities	(817)
Total net tangible assets	$ 272

Business Combinations (Narrativ

Business Combinations (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Business Combinations [Abstract]
Payments to Acquire Businesses, Gross	$ 7,900
Acquired Finite-Lived Intangibles and Goodwill	8,100
Finite-lived Intangible Assets Acquired	1,722	$ 2,032
Goodwill, Acquired During Period	$ 6,379	$ 6,944

Segment Financial Information_3

Segment Financial Information (Narrative) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement [Line Items]
Number of Reportable Segments	4
UNITED STATES
Statement [Line Items]
Disclosure on Geographic Areas Percentage of Revenue from External Customers	97.00%	96.00%	96.00%
Disclosure on Geographic Areas Percentage of Long Lived Assets	75.00%	72.00%
Revenues [Member] | CMS [Member]
Statement [Line Items]
Concentration Risk, Percentage	36.00%	33.00%	30.00%

Segment Financial Information_4

Segment Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement [Line Items]
Premiums, revenues - unaffiliated customers	$ 201,478	$ 189,699	$ 178,087
Products, revenues - unaffiliated customers	34,145	31,597	29,601
Services, revenues - unaffiliated customers	20,016	18,973	17,183
Investment and other income	1,502	1,886	1,376
Total revenues	257,141	242,155	226,247
Earnings from operations	22,405	19,685	17,344
Interest expense	(1,663)	(1,704)	(1,400)
Earnings before income taxes	20,742	17,981	15,944
Total assets	197,289	173,889	152,221
Purchases of property, equipment and capitalized software	2,051	2,071	2,063
Depreciation and amortization	2,891	2,720	2,428
Optum
Statement [Line Items]
Investment and other income	770	749	548
Total revenues	136,308	112,950	101,280
Earnings from operations	10,046	9,359	8,231
Interest expense	0	0	0
Earnings before income taxes	10,046	9,359	8,231
Total assets	106,778	91,971	74,788
Purchases of property, equipment and capitalized software	1,364	1,230	1,302
Depreciation and amortization	1,971	1,794	1,583
Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	201,478	189,699	178,087
Products, revenues - unaffiliated customers	34,145	31,597	29,601
Services, revenues - unaffiliated customers	20,016	18,973	17,183
Total revenues	255,639	240,269	224,871
Unaffiliated Customers | Optum
Statement [Line Items]
Premiums, revenues - unaffiliated customers	9,799	5,916	3,805
Products, revenues - unaffiliated customers	34,145	31,597	29,601
Services, revenues - unaffiliated customers	11,552	10,051	8,817
Total revenues	55,496	47,564	42,223
Affiliated Customers
Statement [Line Items]
Total revenues	0	0	0
Affiliated Customers | Optum
Statement [Line Items]
Total revenues	80,042	64,637	58,509
Operating Segments | UnitedHealthcare
Statement [Line Items]
Investment and other income	732	1,137	828
Total revenues	200,875	193,842	183,476
Earnings from operations	12,359	10,326	9,113
Interest expense	0	0	0
Earnings before income taxes	12,359	10,326	9,113
Total assets	98,229	88,250	82,938
Purchases of property, equipment and capitalized software	687	841	761
Depreciation and amortization	920	926	845
Operating Segments | OptumHealth
Statement [Line Items]
Investment and other income	680	672	481
Total revenues	39,808	30,317	24,145
Earnings from operations	3,434	2,963	2,430
Interest expense	0	0	0
Earnings before income taxes	3,434	2,963	2,430
Total assets	52,073	40,444	29,837
Purchases of property, equipment and capitalized software	715	573	593
Depreciation and amortization	703	565	439
Operating Segments | OptumInsight
Statement [Line Items]
Investment and other income	39	21	21
Total revenues	10,802	10,006	9,008
Earnings from operations	2,725	2,494	2,243
Interest expense	0	0	0
Earnings before income taxes	2,725	2,494	2,243
Total assets	15,425	15,181	11,039
Purchases of property, equipment and capitalized software	461	495	517
Depreciation and amortization	670	672	654
Operating Segments | OptumRx
Statement [Line Items]
Investment and other income	51	56	46
Total revenues	87,498	74,288	69,536
Earnings from operations	3,887	3,902	3,558
Interest expense	0	0	0
Earnings before income taxes	3,887	3,902	3,558
Total assets	39,280	36,346	33,912
Purchases of property, equipment and capitalized software	188	162	192
Depreciation and amortization	598	557	490
Operating Segments | Unaffiliated Customers | UnitedHealthcare
Statement [Line Items]
Premiums, revenues - unaffiliated customers	191,679	183,783	174,282
Products, revenues - unaffiliated customers	0	0	0
Services, revenues - unaffiliated customers	8,464	8,922	8,366
Total revenues	200,143	192,705	182,648
Operating Segments | Unaffiliated Customers | OptumHealth
Statement [Line Items]
Premiums, revenues - unaffiliated customers	9,799	5,916	3,805
Products, revenues - unaffiliated customers	33	31	52
Services, revenues - unaffiliated customers	6,815	5,732	4,925
Total revenues	16,647	11,679	8,782
Operating Segments | Unaffiliated Customers | OptumInsight
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0
Products, revenues - unaffiliated customers	135	116	111
Services, revenues - unaffiliated customers	3,687	3,630	3,280
Total revenues	3,822	3,746	3,391
Operating Segments | Unaffiliated Customers | OptumRx
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0
Products, revenues - unaffiliated customers	33,977	31,450	29,438
Services, revenues - unaffiliated customers	1,050	689	612
Total revenues	35,027	32,139	30,050
Operating Segments | Affiliated Customers | UnitedHealthcare
Statement [Line Items]
Total revenues	0	0	0
Operating Segments | Affiliated Customers | OptumHealth
Statement [Line Items]
Total revenues	22,481	17,966	14,882
Operating Segments | Affiliated Customers | OptumInsight
Statement [Line Items]
Total revenues	6,941	6,239	5,596
Operating Segments | Affiliated Customers | OptumRx
Statement [Line Items]
Total revenues	52,420	42,093	39,440
Optum Eliminations
Statement [Line Items]
Investment and other income	0	0	0
Total revenues	(1,800)	(1,661)	(1,409)
Earnings from operations	0	0	0
Interest expense	0	0	0
Earnings before income taxes	0	0	0
Total assets	0	0	0
Purchases of property, equipment and capitalized software	0	0	0
Depreciation and amortization	0	0	0
Optum Eliminations | Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0
Products, revenues - unaffiliated customers	0	0	0
Services, revenues - unaffiliated customers	0	0	0
Total revenues	0	0	0
Optum Eliminations | Affiliated Customers
Statement [Line Items]
Total revenues	(1,800)	(1,661)	(1,409)
Corporate and Eliminations
Statement [Line Items]
Investment and other income	0	0	0
Total revenues	(80,042)	(64,637)	(58,509)
Earnings from operations	0	0	0
Interest expense	(1,663)	(1,704)	(1,400)
Earnings before income taxes	(1,663)	(1,704)	(1,400)
Total assets	(7,718)	(6,332)	(5,505)
Purchases of property, equipment and capitalized software	0	0	0
Depreciation and amortization	0	0	0
Corporate and Eliminations | Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0
Products, revenues - unaffiliated customers	0	0	0
Services, revenues - unaffiliated customers	0	0	0
Total revenues	0	0	0
Corporate and Eliminations | Affiliated Customers
Statement [Line Items]
Total revenues	$ (80,042)	$ (64,637)	$ (58,509)

Schedule I (Details)

Schedule I (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Cash Dividends Paid to Parent, Consolidated Subsidiaries	$ 8,300	$ 5,600
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Cash Dividends Paid to Parent, Consolidated Subsidiaries	10,000	5,600	$ 5,600
Return of capital to parent company	943	4,497	$ 4,196
Notes Payable	4,900
Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Other Long-term Debt	$ 1,200	$ 1,200

Schedule I Condensed Balance Sh

Schedule I Condensed Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 16,921	$ 10,985	$ 10,866	$ 11,981
Total current assets	53,718	42,634
Other assets	11,510	9,334
Total assets	197,289	173,889	152,221
Current liabilities:
Accounts payable and accrued liabilities	22,495	19,005
Short-term borrowings and current maturities of long-term debt	4,819	3,870
Total current liabilities	72,420	61,782
Long-term debt, less current maturities	38,648	36,808
Other liabilities	12,315	10,144
Total liabilities	126,750	111,727
Commitments and contingencies (Note 4)
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; 946 and 948 issued and outstanding	10	9
Additional paid-in capital	0	7
Retained earnings	69,295	61,178
Accumulated other comprehensive loss	(3,814)	(3,578)
Total liabilities and shareholders’ equity	197,289	173,889
Parent Company [Member]
Current assets:
Cash and cash equivalents	258	46	$ 434	$ 359
Other current assets	562	787
Total current assets	820	833
Equity in net assets of subsidiaries	107,714	93,467
Long-term notes receivable from subsidiaries	5,021	5,079
Other assets	342	794
Total assets	113,897	100,173
Current liabilities:
Accounts payable and accrued liabilities	589	688
Current portion of notes payable to subsidiaries	4,882	750
Short-term borrowings and current maturities of long-term debt	4,465	3,548
Total current liabilities	9,936	4,986
Long-term debt, less current maturities	37,815	35,926
Long-term notes payable to subsidiaries	0	1,314
Other liabilities	655	331
Total liabilities	48,406	42,557
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; 946 and 948 issued and outstanding	10	9
Additional paid-in capital	0	7
Retained earnings	69,295	61,178
Accumulated other comprehensive loss	(3,814)	(3,578)
Total UnitedHealth Group shareholders’ equity	65,491	57,616
Total liabilities and shareholders’ equity	$ 113,897	$ 100,173

Schedule I Balance Sheet Docume

Schedule I Balance Sheet Document (Details) - $ / shares shares in Millions	Dec. 31, 2020	Dec. 31, 2019
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	3,000	3,000
Common stock, shares issued	946	948
Common Stock, shares outstanding	946	948
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10	10
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Parent Company [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	3,000	3,000
Common stock, shares issued	946	948
Common Stock, shares outstanding	946	948
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10	10
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0

Schedule I Condensed Statement

Schedule I Condensed Statement of Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues:
Investment and other income	$ 1,502	$ 1,886	$ 1,376
Total revenues	257,141	242,155	226,247
Operating costs:
Interest expense	1,663	1,704	1,400
Total operating costs	234,736	222,470	208,903
Loss before income taxes	20,742	17,981	15,944
Benefit for income taxes	4,973	3,742	3,562
Net earnings	15,403	13,839	11,986
Other comprehensive (loss) income	(236)	582	(1,517)
Comprehensive income	15,167	14,421	10,469
Parent Company [Member]
Revenues:
Investment and other income	194	209	194
Total revenues	194	209	194
Operating costs:
Operating costs	27	38	35
Interest expense	1,594	1,580	1,285
Total operating costs	1,621	1,618	1,320
Loss before income taxes	(1,427)	(1,409)	(1,126)
Benefit for income taxes	300	293	251
Loss of parent company	(1,127)	(1,116)	(875)
Equity in undistributed income of subsidiaries	16,530	14,955	12,861
Net earnings	15,403	13,839	11,986
Other comprehensive (loss) income	(236)	582	(1,517)
Comprehensive income	$ 15,167	$ 14,421	$ 10,469

Schedule I Statement of Cash Fl

Schedule I Statement of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating activities
Cash flows from operating activities	$ 22,174	$ 18,463	$ 15,713
Investing activities
Cash paid for acquisitions	(7,139)	(8,343)	(5,997)
Other, net	506	(219)	226
Cash flows used for investing activities	(12,532)	(12,699)	(12,385)
Financing activities
Common stock repurchases	(4,250)	(5,500)	(4,500)
Proceeds from common stock issuances	1,440	1,037	838
Proceeds from (repayments of) short-term borrowings, net	872	300	(201)
Proceeds from issuance of long-term debt	4,864	5,444	6,935
Repayments of long-term debt	(3,150)	(1,750)	(2,600)
Other, net	(459)	(1,237)	(1,386)
Cash flows used for financing activities	(3,590)	(5,625)	(4,365)
Cash and cash equivalents, beginning of period	10,985	10,866	11,981
Cash and cash equivalents, end of period	16,921	10,985	10,866
Supplemental cash flow disclosures
Cash paid for interest	1,704	1,627	1,410
Cash paid for income taxes	4,935	3,542	3,257
Parent Company [Member]
Operating activities
Cash flows from operating activities	8,842	9,275	6,099
Investing activities
Issuances of notes to subsidiaries	(628)	(2,722)	(1,420)
Repayments of notes to subsidiaries	1,089	2,249	1,419
Cash paid for acquisitions	(7,706)	(9,645)	(4,066)
Return of capital to parent company	943	4,497	4,196
Capital contributions to subsidiaries	(43)	(803)	(1,259)
Other, net	143	490	4
Cash flows used for investing activities	(6,202)	(5,934)	(1,126)
Financing activities
Common stock repurchases	(4,250)	(5,500)	(4,500)
Proceeds from common stock issuances	1,440	1,037	838
Cash dividends paid	(4,584)	(3,932)	(3,320)
Proceeds from (repayments of) short-term borrowings, net	872	300	(201)
Proceeds from issuance of long-term debt	4,864	5,444	6,935
Repayments of long-term debt	(3,150)	(1,750)	(2,600)
Proceeds (repayments) of notes from subsidiary	2,818	1,207	(1,127)
Other, net	(438)	(535)	(923)
Cash flows used for financing activities	(2,428)	(3,729)	(4,898)
Increase (decrease) in cash and cash equivalents	212	(388)	75
Cash and cash equivalents, beginning of period	46	434	359
Cash and cash equivalents, end of period	258	46	434
Supplemental cash flow disclosures
Cash paid for interest	1,633	1,506	1,294
Cash paid for income taxes	$ 4,185	$ 2,590	$ 2,379

Schedule I Maturities of Short-

Schedule I Maturities of Short-Term Borrowings and Long-Term Debt (Details) $ in Millions	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
2021	$ 4,800
2022	3,180
2023	2,290
2024	1,665
2025	2,465
Thereafter	29,349
Parent Company [Member]
Debt Instrument [Line Items]
2021	4,446
2022	3,015
2023	2,125
2024	1,500
2025	2,300
Thereafter	$ 29,177