UnitedHealth (UNH) 10-Q 7 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	9 Months Ended
	Sep. 30, 2017	Oct. 31, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Entitiy Registrant Name	UNITEDHEALTH GROUP INC
Entitiy Central Index Key	731,766
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		969,067,449

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 16,269	$ 10,430
Short-term investments	3,525	2,845
Accounts receivable, net	8,638	8,152
Other current receivables, net	6,826	7,499
Assets under management	3,082	3,105
Prepaid expenses and other current assets	2,581	1,848
Total current assets	40,921	33,879
Long-term investments	27,703	23,868
Property, equipment and capitalized software, net	6,562	5,901
Goodwill	53,402	47,584
Other intangible assets, net	8,457	8,541
Other assets	3,387	3,037
Total assets	140,432	122,810
Current liabilities:
Medical costs payable	17,963	16,391
Accounts payable and accrued liabilities	15,878	13,361
Commercial paper and current maturities of long-term debt	4,539	7,193
Unearned revenues	6,635	1,968
Other current liabilities	13,073	10,339
Total current liabilities	58,088	49,252
Long-term debt, less current maturities	24,723	25,777
Future policy benefits	2,535	2,524
Deferred income taxes	2,697	2,761
Other liabilities	2,909	2,307
Total liabilities	90,952	82,621
Commitments and contingencies (Note 8)
Redeemable noncontrolling interests	2,170	2,012
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; 969 and 952 issued and outstanding	10	10
Additional paid-in capital	1,801	0
Retained earnings	45,840	40,945
Accumulated other comprehensive loss	(2,353)	(2,681)
Nonredeemable noncontrolling interest	2,012	(97)
Total equity	47,310	38,177
Total liabilities, redeemable noncontrolling interests and equity	$ 140,432	$ 122,810

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheet (Parenthetical) - $ / shares shares in Millions	Sep. 30, 2017	Dec. 31, 2016
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	3,000	3,000
Common stock, shares issued	969	952
Common stock, shares outstanding	969	952
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

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Premiums	$ 39,552	$ 36,142	$ 118,075	$ 107,366
Products	6,665	6,696	19,209	19,699
Services	3,858	3,264	11,089	9,673
Investment and other income	247	191	725	567
Total revenues	50,322	46,293	149,098	137,305
Operating costs:
Medical costs	32,201	29,040	96,829	87,342
Operating costs	7,387	7,033	21,737	20,584
Cost of products sold	6,068	6,125	17,633	18,108
Depreciation and amortization	578	515	1,667	1,528
Total operating costs	46,234	42,713	137,866	127,562
Earnings from operations	4,088	3,580	11,232	9,743
Interest expense	(294)	(269)	(878)	(799)
Earnings before income taxes	3,794	3,311	10,354	8,944
Provision for income taxes	(1,233)	(1,333)	(3,252)	(3,579)
Net earnings	2,561	1,978	7,102	5,365
Earnings attributable to noncontrolling interests	(76)	(10)	(161)	(32)
Net earnings attributable to UnitedHealth Group common shareholders	$ 2,485	$ 1,968	$ 6,941	$ 5,333
Earnings per share attributable to UnitedHealth Group common shareholders:
Basic	$ 2.57	$ 2.07	$ 7.22	$ 5.60
Diluted	$ 2.51	$ 2.03	$ 7.06	$ 5.51
Basic weighted-average number of common shares outstanding	968	952	962	952
Dilutive effect of common share equivalents	21	17	21	16
Diluted weighted-average number of common shares outstanding	989	969	983	968
Anti-dilutive shares excluded from the calculation of dilutive effect of common share equivalents	1	1	6	3
Cash dividends declared per common share	$ 0.750	$ 0.625	$ 2.125	$ 1.750

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net earnings	$ 2,561	$ 1,978	$ 7,102	$ 5,365
Other comprehensive income (loss):
Gross unrealized gains (losses) on investment securities during the period	44	(21)	313	473
Income tax effect	(17)	7	(111)	(173)
Total unrealized gains (losses), net of tax	27	(14)	202	300
Gross reclassification adjustment for net realized gains included in net earnings	(10)	(26)	(51)	(97)
Income tax effect	4	9	19	35
Total reclassification adjustment, net of tax	(6)	(17)	(32)	(62)
Total foreign currency translation gains (losses)	217	(69)	158	793
Other comprehensive income (loss)	238	(100)	328	1,031
Comprehensive income	2,799	1,878	7,430	6,396
Comprehensive income attributable to noncontrolling interests	(76)	(10)	(161)	(32)
Comprehensive income attributable to UnitedHealth Group common shareholders	$ 2,723	$ 1,868	$ 7,269	$ 6,364

Condensed Consolidated Stateme6

Condensed 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 Gains (Losses) on Investments [Member]	Foreign Currency Translation (Losses) Gains [Member]	Nonredeemable Noncontrolling Interest [Member]
Balance (in shares) at Dec. 31, 2015		953
Balance at Dec. 31, 2015	$ 33,725	$ 10	$ 29	$ 37,125	$ 56	$ (3,390)	$ (105)
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets at Dec. 31, 2015	28			28
Net earnings attributable to UnitedHealth Group common shareholders	5,333			5,333
Net earnings attributable to nonredeemable noncontrolling interest							31
Net Earnings, Including Portion Attributable to Nonredeemable Noncontrolling Interest	5,364
Other comprehensive income (loss)	1,031				238	793
Issuances of common stock, and related tax effects (in shares)		8
Issuances of common stock, and related tax effects	187	$ 0	187
Share-based compensation	350		350
Common share repurchases (in shares)		(9)
Common share repurchases	(1,117)	$ 0	(242)	(875)
Cash dividends paid on common shares	(1,666)			(1,666)
Acquisition of redeemable noncontrolling interest shares	(143)		(143)
Redeemable noncontrolling interests fair value and other adjustments	(181)		(181)
Distribution to nonredeemable noncontrolling interest	(24)						(24)
Balance (in shares) at Sep. 30, 2016		952
Balance at Sep. 30, 2016	$ 37,554	$ 10	0	39,945	294	(2,597)	(98)
Balance (in shares) at Dec. 31, 2016	952	952
Balance at Dec. 31, 2016	$ 38,177	$ 10	0	40,945	(97)	(2,584)	(97)
Net earnings attributable to UnitedHealth Group common shareholders	6,941			6,941
Net earnings attributable to nonredeemable noncontrolling interest							120
Net Earnings, Including Portion Attributable to Nonredeemable Noncontrolling Interest	7,061
Other comprehensive income (loss)	328				170	158
Issuances of common stock, and related tax effects (in shares)		24
Issuances of common stock, and related tax effects	2,156	$ 0	2,156
Share-based compensation	447		447
Common share repurchases (in shares)		(7)
Common share repurchases	(1,173)	$ 0	(1,173)
Cash dividends paid on common shares	(2,046)			(2,046)
Redeemable noncontrolling interests fair value and other adjustments	371		371
Acquisition of nonredeemable noncontrolling interests	2,111						2,111
Distribution to nonredeemable noncontrolling interest	$ (122)						(122)
Balance (in shares) at Sep. 30, 2017	969	969
Balance at Sep. 30, 2017	$ 47,310	$ 10	$ 1,801	$ 45,840	$ 73	$ (2,426)	$ 2,012

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating activities
Net earnings	$ 7,102	$ 5,365
Noncash items:
Depreciation and amortization	1,667	1,528
Deferred income taxes	(459)	(405)
Share-based compensation	456	369
Other, net	168	(68)
Net change in other operating items, net of effects from acquisitions and changes in AARP balances:
Accounts receivable	(244)	(580)
Other assets	(763)	(1,835)
Medical costs payable	1,305	1,984
Accounts payable and other liabilities	2,283	1,280
Unearned revenues	4,658	3,566
Cash flows from operating activities	16,173	11,204
Investing activities
Purchases of investments	(10,626)	(12,231)
Sales of investments	2,809	4,422
Maturities of investments	4,251	3,040
Cash paid for acquisitions, net of cash assumed	(908)	(2,727)
Purchases of property, equipment and capitalized software	(1,391)	(1,220)
Other, net	(30)	(25)
Cash flows used for investing activities	(5,895)	(8,741)
Financing activities
Common share repurchases	(1,173)	(1,117)
Cash dividends paid	(2,046)	(1,666)
Proceeds from common stock issuances	604	387
Proceeds from issuance of long-term debt	1,342	2,485
Repayments of long-term debt	(2,867)	(2,101)
(Repayments of) proceeds from commercial paper, net	(3,352)	693
Customer funds administered	3,659	1,249
Other, net	(624)	(590)
Cash flows used for financing activities	(4,457)	(660)
Effect of exchange rate changes on cash and cash equivalents	18	70
Increase in cash and cash equivalents	5,839	1,873
Cash and cash equivalents, beginning of period	10,430	10,923
Cash and Cash Equivalents, end of period	16,269	12,796
Supplemental Schedule of Noncash Investing Activities
Common stock issued for acquisition	$ 2,164	$ 0

Basis of Presentation (Notes)

Basis of Presentation (Notes)	9 Months Ended
	Sep. 30, 2017
Basis of Presentation and Significant Accounting Policies [Text Block]	Basis of Presentation and Significant Accounting Policies UnitedHealth Group Incorporated (individually and together with its subsidiaries, “UnitedHealth Group” and “the Company”) is a diversified health and well-being company dedicated to helping people live healthier lives and helping make the health system work better for everyone. Through its diversified family of businesses, the Company leverages core competencies in advanced, enabling technology; health care data, information and intelligence; and clinical care management and coordination to help meet the demands of the health system. These core competencies are deployed within the Company’s two distinct, but strategically aligned, business platforms: health benefits operating under UnitedHealthcare and health services operating under Optum. The Company has prepared the Condensed Consolidated Financial Statements according to U.S. Generally Accepted Accounting Principles (GAAP) and has included the accounts of UnitedHealth Group and its subsidiaries. The year-end condensed consolidated balance sheet was derived from audited financial statements, but does not include all disclosures required by GAAP. In accordance with the rules and regulations of the U.S. Securities and Exchange Commission (SEC), the Company has omitted certain footnote disclosures that would substantially duplicate the disclosures contained in its annual audited Consolidated Financial Statements. Therefore, these Condensed Consolidated Financial Statements should be read together with the Consolidated Financial Statements and the Notes included in Part II, Item 8, “Financial Statements” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 as filed with the SEC ( 2016 10-K). The accompanying Condensed Consolidated Financial Statements include all normal recurring adjustments necessary to present the interim financial statements fairly. Use of Estimates These Condensed Consolidated Financial Statements include certain amounts based on the Company’s best estimates and judgments. The Company’s most significant estimates relate to estimates and judgments for medical costs payable and revenues, valuation and impairment analysis of goodwill and other intangible assets and valuations of certain investments. Certain of these estimates require the application of complex assumptions and judgments, often because they involve matters that are inherently uncertain and will likely change in subsequent periods. The impact of any change in estimates is included in earnings in the period in which the estimate is adjusted. Revenues The Company’s revenues include premium, product, and service revenues. Service revenues include net patient service revenues that are recorded based upon established billing rates, less allowances for contractual adjustments, and are recognized as services are provided. For more information about the Company’s revenues, see Notes 2 and 13 of Notes to the Consolidated Financial Statements in Part II, Item 8, “Financial Statements” in the 2016 10-K. See Note 9 for disaggregation of revenue by segment and type. As of September 30, 2017 , accounts receivables related to products and services were $3.5 billion . For the three and nine months ended September 30, 2017 , the Company had no material bad-debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the Condensed Consolidated Balance Sheet as of September 30, 2017 . For the three and nine months ended September 30, 2017 , 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 that have 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. Health Insurance Industry Tax The Patient Protection and Affordable Care Act (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. A provision in the 2016 Federal Budget imposed a one year moratorium for 2017 on the collection of the Health Insurance Industry Tax. The Company has experienced a lower effective income tax rate in 2017 as compared to 2016 primarily due to the moratorium. The remainder of the accounting policies disclosed in Note 2 of Notes to the Consolidated Financial Statements in Part II, Item 8, “Financial Statements” in the 2016 10-K remain unchanged. Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) No. 2016-02, “Leases (Topic 842)” (ASU 2016-02). Under ASU 2016-02, an entity will be required to recognize assets and liabilities for the rights and obligations created by leases on the entity’s balance sheet for both finance and operating leases. For leases with a term of 12 months or less, an entity can elect to not recognize lease assets and lease liabilities and expense the lease over a straight-line basis for the term of the lease. ASU 2016-02 will require new disclosures that depict the amount, timing and uncertainty of cash flows pertaining to an entity’s leases. Companies are required to adopt the new standard using a modified retrospective approach for annual and interim periods beginning after December 15, 2018. Early adoption of ASU 2016-02 is permitted. When adopted, the Company does not expect ASU 2016-02 to have a material impact on its results of operations, equity or cash flows. The impact of ASU 2016-02 on the Company’s consolidated financial position will be based on leases outstanding at the time of adoption. In January 2016, the FASB issued ASU 2016-01, “Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities” (ASU 2016-01). The new guidance changes the current accounting related to (i) the classification and measurement of certain equity investments, (ii) the presentation of changes in the fair value of financial liabilities measured under the fair value option that are due to instrument-specific credit risk, and (iii) certain disclosures associated with the fair value of financial instruments. Most notably, ASU 2016-01 requires that equity investments, with certain exemptions, be measured at fair value with changes in fair value recognized in net income as opposed to other comprehensive income. The new guidance is effective for annual and interim reporting periods beginning after December 15, 2017. As of September 30, 2017 , based on equity securities held, the Company does not expect ASU 2016-01 to have a material impact on its consolidated financial position, results of operations, equity or cash flows. The Company will continue to evaluate any changes in its mix of investments or market conditions and the related impact of ASU 2016-01. Recently Adopted Accounting Standards In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” as modified by subsequently issued ASUs 2015-14, 2016-08, 2016-10, 2016-12 and 2016-20 (collectively ASU 2014-09). ASU 2014-09 superseded existing revenue recognition standards with a single model unless those contracts are within the scope of other standards (e.g., an insurance entity’s insurance contracts). The revenue recognition principle in ASU 2014-09 is that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company early adopted the new standard effective January 1, 2017, as allowed, using the modified retrospective approach. A significant majority of the Company’s revenues are not subject to the new guidance. The adoption of ASU 2014-09 did not have a material impact on the Company’s consolidated financial position, results of operations, equity or cash flows as of the adoption date or for the nine months ended September 30, 2017 . The Company has included the disclosures required by ASU 2014-09 above. The Company has determined that there have been no other recently adopted or issued accounting standards that had, or will have, a material impact on its Condensed Consolidated Financial Statements.

Investments (Notes)

Investments (Notes)	9 Months Ended
	Sep. 30, 2017
Investments [Abstract]
Investments [Text Block]	Investments A summary of short-term and long-term investments by major security type is as follows: (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value September 30, 2017 Debt securities - available-for-sale: U.S. government and agency obligations $ 2,708 $ 3 $ (24 ) $ 2,687 State and municipal obligations 6,997 117 (20 ) 7,094 Corporate obligations 13,092 88 (26 ) 13,154 U.S. agency mortgage-backed securities 3,946 13 (28 ) 3,931 Non-U.S. agency mortgage-backed securities 1,018 5 (4 ) 1,019 Total debt securities - available-for-sale 27,761 226 (102 ) 27,885 Equity securities 1,949 30 (38 ) 1,941 Debt securities - held-to-maturity: U.S. government and agency obligations 259 — — 259 State and municipal obligations 4 — — 4 Corporate obligations 285 — — 285 Total debt securities - held-to-maturity 548 — — 548 Total investments $ 30,258 $ 256 $ (140 ) $ 30,374 December 31, 2016 Debt securities - available-for-sale: U.S. government and agency obligations $ 2,294 $ 1 $ (31 ) $ 2,264 State and municipal obligations 7,120 40 (101 ) 7,059 Corporate obligations 10,944 41 (58 ) 10,927 U.S. agency mortgage-backed securities 2,963 7 (43 ) 2,927 Non-U.S. agency mortgage-backed securities 1,009 3 (10 ) 1,002 Total debt securities - available-for-sale 24,330 92 (243 ) 24,179 Equity securities 2,036 52 (47 ) 2,041 Debt securities - held-to-maturity: U.S. government and agency obligations 250 1 — 251 State and municipal obligations 5 — — 5 Corporate obligations 238 — — 238 Total debt securities - held-to-maturity 493 1 — 494 Total investments $ 26,859 $ 145 $ (290 ) $ 26,714 The amortized cost and fair value of debt securities as of September 30, 2017 , by contractual maturity, were as follows: Available-for-Sale Held-to-Maturity (in millions) Amortized Cost Fair Value Amortized Fair Due in one year or less $ 3,650 $ 3,651 $ 165 $ 165 Due after one year through five years 10,607 10,645 125 125 Due after five years through ten years 6,476 6,540 113 113 Due after ten years 2,064 2,099 145 145 U.S. agency mortgage-backed securities 3,946 3,931 — — Non-U.S. agency mortgage-backed securities 1,018 1,019 — — Total debt securities $ 27,761 $ 27,885 $ 548 $ 548 The fair value of available-for-sale investments with gross unrealized losses by major security type and length of time that individual securities have been in a continuous unrealized loss position were as follows: Less Than 12 Months 12 Months or Greater Total (in millions) Fair Value Gross Unrealized Losses Fair Value Gross Fair Value Gross September 30, 2017 Debt securities - available-for-sale: U.S. government and agency obligations $ 1,635 $ (11 ) $ 532 $ (13 ) $ 2,167 $ (24 ) State and municipal obligations 1,910 (15 ) 429 (5 ) 2,339 (20 ) Corporate obligations 3,958 (17 ) 496 (9 ) 4,454 (26 ) U.S. agency mortgage-backed securities 2,233 (24 ) 146 (4 ) 2,379 (28 ) Non-U.S. agency mortgage-backed securities 351 (3 ) 49 (1 ) 400 (4 ) Total debt securities - available-for-sale $ 10,087 $ (70 ) $ 1,652 $ (32 ) $ 11,739 $ (102 ) Equity securities $ 59 $ (4 ) $ 97 $ (34 ) $ 156 $ (38 ) December 31, 2016 Debt securities - available-for-sale: U.S. government and agency obligations $ 1,794 $ (31 ) $ — $ — $ 1,794 $ (31 ) State and municipal obligations 4,376 (101 ) — — 4,376 (101 ) Corporate obligations 5,128 (56 ) 137 (2 ) 5,265 (58 ) U.S. agency mortgage-backed securities 2,247 (40 ) 79 (3 ) 2,326 (43 ) Non-U.S. agency mortgage-backed securities 544 (7 ) 97 (3 ) 641 (10 ) Total debt securities - available-for-sale $ 14,089 $ (235 ) $ 313 $ (8 ) $ 14,402 $ (243 ) Equity securities $ 93 $ (5 ) $ 91 $ (42 ) $ 184 $ (47 ) The Company’s unrealized losses from all securities as of September 30, 2017 were generated from 9,000 positions out of a total of 29,000 positions. The Company believes that it will collect the principal and interest due on its debt securities that have an amortized cost in excess of fair value. The unrealized losses were primarily caused by interest rate increases and not by unfavorable changes in the credit quality associated with these securities. At each reporting period, the Company evaluates securities for impairment when the fair value of the investment is less than its amortized cost. The Company evaluated the underlying credit quality and credit ratings of the issuers, noting no significant deterioration since purchase. As of September 30, 2017 , 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 Company’s investments in equity securities consist of investments in Brazilian real denominated fixed-income funds, employee savings plan related investments, venture capital funds, and dividend paying stocks. The Company evaluated its investments in equity securities for severity and duration of unrealized loss, overall market volatility and other market factors. Additionally, as of September 30, 2017 , the Company’s investments included $854 million of equity method investments in operating businesses in the health care sector.

Fair Value (Notes)

Fair Value (Notes)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value [Text Block]	Fair Value Certain assets and liabilities are measured at fair value in the Condensed Consolidated Financial Statements or have fair values disclosed in the Notes to the Condensed Consolidated Financial Statements. These assets and liabilities are classified into one of three levels of a hierarchy defined by GAAP. For a description of the methods and assumptions that are used to estimate the fair value and determine the fair value hierarchy classification of each class of financial instrument, see Note 4 of Notes to the Consolidated Financial Statements in Part II, Item 8, “Financial Statements” in the 2016 10-K. The following table presents a summary of fair value measurements by level and carrying values for items measured at fair value on a recurring basis in the Condensed Consolidated Balance Sheets: (in millions) Quoted Prices in Active Markets (Level 1) Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Total Fair and Carrying Value September 30, 2017 Cash and cash equivalents $ 13,462 $ 2,807 $ — $ 16,269 Debt securities - available-for-sale: U.S. government and agency obligations 2,405 282 — 2,687 State and municipal obligations — 7,094 — 7,094 Corporate obligations 73 12,947 134 13,154 U.S. agency mortgage-backed securities — 3,931 — 3,931 Non-U.S. agency mortgage-backed securities — 1,019 — 1,019 Total debt securities - available-for-sale 2,478 25,273 134 27,885 Equity securities 1,804 14 123 1,941 Assets under management 763 2,319 — 3,082 Interest rate swap assets — 50 — 50 Total assets at fair value $ 18,507 $ 30,463 $ 257 $ 49,227 Percentage of total assets at fair value 37 % 62 % 1 % 100 % Interest rate swap liabilities $ — $ 12 $ — $ 12 December 31, 2016 Cash and cash equivalents $ 10,386 $ 44 $ — $ 10,430 Debt securities - available-for-sale: U.S. government and agency obligations 2,017 247 — 2,264 State and municipal obligations — 7,059 — 7,059 Corporate obligations 21 10,804 102 10,927 U.S. agency mortgage-backed securities — 2,927 — 2,927 Non-U.S. agency mortgage-backed securities — 1,002 — 1,002 Total debt securities - available-for-sale 2,038 22,039 102 24,179 Equity securities 1,591 13 437 2,041 Assets under management 1,064 2,041 — 3,105 Interest rate swap assets — 55 — 55 Total assets at fair value $ 15,079 $ 24,192 $ 539 $ 39,810 Percentage of total assets at fair value 38 % 61 % 1 % 100 % Interest rate swap liabilities $ — $ 14 $ — $ 14 Transfers between levels, if any, are recorded as of the beginning of the reporting period in which the transfer occurs; there were no transfers between Levels 1, 2 or 3 of any financial assets or liabilities during the nine months ended September 30, 2017 or 2016 . The following table presents a summary of fair value measurements by level and carrying values for certain financial instruments not measured at fair value on a recurring basis in the Condensed Consolidated Balance Sheets: (in millions) Quoted Prices in Active Markets (Level 1) Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Total Fair Value Total Carrying Value September 30, 2017 Debt securities - held-to-maturity: U.S. government and agency obligations $ 256 $ 3 $ — $ 259 $ 259 State and municipal obligations — — 4 4 4 Corporate obligations 17 1 267 285 285 Total debt securities - held-to-maturity $ 273 $ 4 $ 271 $ 548 $ 548 Other assets $ — $ 477 $ — $ 477 $ 475 Long-term debt and other financing obligations $ — $ 31,686 $ — $ 31,686 $ 28,959 December 31, 2016 Debt securities - held-to-maturity: U.S. government and agency obligations $ 251 $ — $ — $ 251 $ 250 State and municipal obligations — — 5 5 5 Corporate obligations 20 8 210 238 238 Total debt securities - held-to-maturity $ 271 $ 8 $ 215 $ 494 $ 493 Other assets $ — $ 476 $ — $ 476 $ 471 Long-term debt and other financing obligations $ — $ 31,295 $ — $ 31,295 $ 29,337 Nonfinancial assets and liabilities or financial assets and liabilities that are measured at fair value on a nonrecurring basis are subject to fair value adjustments only in certain circumstances, such as when the Company records an impairment. There were no significant fair value adjustments for these assets and liabilities recorded during the nine months ended September 30, 2017 or 2016 .

Other Current Receivables (Note

Other Current Receivables (Notes)	9 Months Ended
	Sep. 30, 2017
Other Current Receivables [Line Items]
Other Current Receivables [Text Block]	Other Current Receivables The Company’s pharmacy care services businesses contract with pharmaceutical manufacturers, some of which provide rebates based on use of the manufacturers’ products by the Company’s clients. As of September 30, 2017 and December 31, 2016 , total pharmaceutical manufacturer rebates receivable included in other receivables in the Condensed Consolidated Balance Sheets amounted to $4.0 billion and $3.3 billion , respectively. See Note 2 of Notes to the Consolidated Financial Statements in Part II, Item 8, “Financial Statements” in the 2016 10-K for more information on the Company’s pharmaceutical manufacturer rebates.

Medical Costs Payable (Notes)

Medical Costs Payable (Notes)	9 Months Ended
	Sep. 30, 2017
Medical Costs Payable Text Block	Medical Costs Payable The following table shows the components of the change in medical costs payable for the nine months ended September 30: (in millions) 2017 2016 Medical costs payable, beginning of period $ 16,391 $ 14,330 Acquisitions 76 — Reported medical costs: Current year 97,519 87,532 Prior years (690 ) (190 ) Total reported medical costs 96,829 87,342 Medical payments: Payments for current year (81,237 ) (72,092 ) Payments for prior years (14,096 ) (13,080 ) Total medical payments (95,333 ) (85,172 ) Medical costs payable, end of period $ 17,963 $ 16,500 For the nine months ended September 30, 2017 , the medical cost reserve development was primarily driven by lower than expected health system utilization levels. For the nine months ended September 30, 2016 , no individual factors were significant. Medical costs payable included reserves for claims incurred by insured customers but not yet reported to the Company of $12.4 billion and $11.6 billion at September 30, 2017 and December 31, 2016, respectively.

Commercial Paper and Long-Term

Commercial Paper and Long-Term Debt (Notes)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Commercial Paper and Long-Term Debt [Text Block]	Commercial Paper and Long-Term Debt Commercial paper and senior unsecured long-term debt consisted of the following: September 30, 2017 December 31, 2016 (in millions, except percentages) Par Carrying Value Fair Value Par Value Carrying Fair Value Commercial paper $ 304 $ 303 $ 303 $ 3,633 $ 3,633 $ 3,633 Floating rate notes due January 2017 — — — 750 750 750 6.000% notes due June 2017 — — — 441 446 450 1.450% notes due July 2017 — — — 750 750 751 1.400% notes due October 2017 625 625 625 625 624 626 6.000% notes due November 2017 156 157 157 156 159 163 1.400% notes due December 2017 750 750 750 750 751 750 6.000% notes due February 2018 1,100 1,102 1,118 1,100 1,107 1,153 1.900% notes due July 2018 1,500 1,498 1,504 1,500 1,496 1,507 1.700% notes due February 2019 750 749 750 750 748 748 1.625% notes due March 2019 500 501 499 500 501 498 2.300% notes due December 2019 500 497 504 500 498 504 2.700% notes due July 2020 1,500 1,496 1,530 1,500 1,495 1,523 3.875% notes due October 2020 450 449 473 450 450 474 4.700% notes due February 2021 400 407 431 400 409 433 2.125% notes due March 2021 750 746 750 750 745 741 3.375% notes due November 2021 500 497 520 500 497 519 2.875% notes due December 2021 750 748 769 750 748 760 2.875% notes due March 2022 1,100 1,063 1,125 1,100 1,057 1,114 3.350% notes due July 2022 1,000 996 1,044 1,000 995 1,030 0.000% notes due November 2022 15 11 12 15 11 12 2.750% notes due February 2023 625 612 632 625 609 622 2.875% notes due March 2023 750 771 765 750 771 753 3.750% notes due July 2025 2,000 1,987 2,122 2,000 1,986 2,070 3.100% notes due March 2026 1,000 995 1,012 1,000 994 986 3.450% notes due January 2027 750 745 776 750 745 762 3.375% notes due April 2027 625 618 643 — — — 4.625% notes due July 2035 1,000 991 1,146 1,000 991 1,090 5.800% notes due March 2036 850 837 1,071 850 837 1,034 6.500% notes due June 2037 500 491 683 500 491 643 6.625% notes due November 2037 650 641 903 650 640 850 6.875% notes due February 2038 1,100 1,075 1,561 1,100 1,075 1,497 5.700% notes due October 2040 300 296 383 300 296 366 5.950% notes due February 2041 350 345 460 350 345 437 4.625% notes due November 2041 600 588 673 600 588 634 4.375% notes due March 2042 502 483 543 502 483 509 3.950% notes due October 2042 625 607 641 625 606 609 4.250% notes due March 2043 750 734 801 750 734 765 4.750% notes due July 2045 2,000 1,972 2,310 2,000 1,972 2,203 4.200% notes due January 2047 750 738 799 750 737 759 4.250% notes due April 2047 725 717 777 — — — Total commercial paper and long-term debt $ 29,102 $ 28,838 $ 31,565 $ 33,022 $ 32,770 $ 34,728 In 2017, the Company repaid $926 million in debt assumed in the first quarter in connection with an acquisition. The Company’s long-term debt obligations also included $424 million and $200 million of other financing obligations, of which $104 million and $80 million were classified as current as of September 30, 2017 and December 31, 2016 , respectively. Long-term Debt In October 2017, the Company issued $4.0 billion of senior unsecured notes consisting of the following: (in millions, except percentages) Par Floating rate notes due October 2020 $ 300 1.950% notes due October 2020 900 2.375% notes due October 2022 900 2.950% notes due October 2027 950 3.750% notes due October 2047 950 Commercial Paper and Bank Credit Facilities Commercial paper consists of short-duration, senior unsecured debt privately placed on a discount basis through broker-dealers. As of September 30, 2017 , the Company’s outstanding commercial paper had a weighted-average annual interest rate of 1.4% . The Company has $3.0 billion five-year, $2.0 billion three-year and $1.0 billion 364-day revolving bank credit facilities with 23 banks, which mature in December 2021 , December 2019 and December 2017, respectively. These facilities provide liquidity support for the Company’s commercial paper program and are available for general corporate purposes. As of September 30, 2017 , 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 September 30, 2017 , annual interest rates would have ranged from 2.0% to 2.3% . Debt Covenants The Company’s bank credit facilities contain various covenants, including covenants requiring the Company to maintain a defined debt to debt-plus-shareholders’ equity ratio of not more than 55% . The Company was in compliance with its debt covenants as of September 30, 2017 .

Shareholders' Equity (Notes)

Shareholders' Equity (Notes)	9 Months Ended
	Sep. 30, 2017
Class of Stock [Line Items]
Stockholders' Equity Note Disclosure [Text Block]	Shareholders' Equity Dividends In June 2017, the Company’s Board of Directors increased the Company’s quarterly cash dividend to shareholders to an annual dividend rate of $3.00 per share from $2.50 per share, which the Company had paid since June 2016. 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 2017 dividend payments: Payment Date Amount per Share Total Amount Paid (in millions) March 10, 2017 $ 0.625 $ 596 June 27, 2017 0.750 724 September 19, 2017 0.750 726

Commitments and Contingencies (

Commitments and Contingencies (Notes)	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies Legal Matters Because of the nature of its businesses, the Company is frequently made party to a variety of legal actions and regulatory inquiries, including demands, audits, class actions and suits brought by members, care providers, consumer advocacy organizations, customers, shareholders and regulators, relating to the Company’s businesses, including management and administration of health benefit plans and other services. These matters include medical malpractice, employment, intellectual property, antitrust, privacy and contract claims and claims related to health care benefits coverage and other business practices. The Company records liabilities for its estimates of probable costs resulting from these matters where appropriate. Estimates of costs resulting from legal and regulatory matters involving the Company are inherently difficult to predict, particularly where the matters: involve indeterminate claims for monetary damages or may involve fines, penalties or punitive damages; present novel legal theories or represent a shift in regulatory policy; involve a large number of claimants or regulatory bodies; are in the early stages of the proceedings; or could result in a change in business practices. Accordingly, the Company is often unable to estimate the losses or ranges of losses for those matters where there is a reasonable possibility or it is probable that a loss may be incurred. Litigation Matters California Claims Processing Matter. On January 25, 2008, the California Department of Insurance (CDI) issued an Order to Show Cause to PacifiCare Life and Health Insurance Company, a subsidiary of the Company, alleging violations of certain insurance statutes and regulations related to an alleged failure to include certain language in standard claims correspondence, timeliness and accuracy of claims processing, interest payments, care provider contract implementation, care provider dispute resolution and other related matters. Although the Company believes that CDI had never before issued a fine in excess of $8 million , CDI advocated a fine of approximately $325 million in this matter. The matter was the subject of an administrative hearing before a California administrative law judge beginning in December 2009, and in August 2013, the administrative law judge issued a nonbinding proposed decision recommending a fine of $11.5 million . The California Insurance Commissioner (Commissioner) rejected the administrative law judge’s recommendation and on June 9, 2014, issued his own decision imposing a fine of approximately $174 million . On July 10, 2014, the Company filed a lawsuit in California state court challenging the Commissioner’s decision. On September 8, 2015, in the first phase of that lawsuit, the California state court issued an order invalidating certain of the regulations the Commissioner had relied upon in issuing his decision and penalty. On September 21, 2017, the court entered a final ruling reversing all of the penalties imposed and remanding certain issues to the Commissioner. The Company cannot reasonably estimate the range of loss, if any, that may result from this matter given the procedural status of the dispute, the wide range of possible outcomes, the legal issues presented (including the legal basis for the majority of the alleged violations), the inherent difficulty in predicting a regulatory fine in the event of a remand, and the various remedies and levels of judicial review that remain available to the Company. 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 the CMS, state insurance and health and welfare departments, the Brazilian national regulatory agency for private health insurance and plans (the Agência Nacional de Saúde Suplementar), 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, the SEC, the Internal Revenue Service, the U.S. Drug Enforcement Administration, the Brazilian federal revenue service (the Secretaria da Receita Federal), the U.S. Department of Labor, the Federal Deposit Insurance Corporation, the Defense Contract Audit Agency and other 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 Department of Justice (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 that the Company, along with a number of other Medicare Advantage plans, made improper risk adjustment submissions and violated the False Claims Act. On March 24, 2017, DOJ intervened in a separate lawsuit initially asserted against the Company and filed by a whistleblower in 2009 concerning risk adjustment submissions by Medicare Advantage plans. On October 5, 2017, in one of the cases, the district court dismissed certain of DOJ’s claims with prejudice, and dismissed all of DOJ’s remaining claims with leave to file a further amended complaint; on October 12, the DOJ filed a notice of dismissal without prejudice of the case. The other case is now pending in the U.S. District Court for the Central District of California. The Company cannot reasonably estimate the outcome that may result from these matters given their current posture.

Segment Financial Information (

Segment Financial Information (Notes)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segment Financial Information [Text Block]	Segment Financial Information The Company’s four reportable segments are UnitedHealthcare, OptumHealth, OptumInsight and OptumRx . For more information on the Company’s segments see Part I, Item I, “Business” and Note 13 of Notes to the Consolidated Financial Statements in Part II, Item 8, “Financial Statements” in the 2016 10-K. As of September 30, 2017 , OptumHealth’s total assets were $26.1 billion as compared to $18.7 billion as of December 31, 2016. The increase was due to acquisitions, which increased goodwill by $5.1 billion during the nine months ended September 30, 2017 . The following tables present reportable segment financial information: Optum (in millions) UnitedHealthcare OptumHealth OptumInsight OptumRx Optum Eliminations Optum Corporate and Eliminations Consolidated Three Months Ended September 30, 2017 Revenues - unaffiliated customers: Premiums $ 38,576 $ 976 $ — $ — $ — $ 976 $ — $ 39,552 Products — 10 29 6,626 — 6,665 — 6,665 Services 2,005 1,040 677 136 — 1,853 — 3,858 Total revenues - unaffiliated customers 40,581 2,026 706 6,762 — 9,494 — 50,075 Total revenues - affiliated customers — 3,138 1,297 9,186 (324 ) 13,297 (13,297 ) — Investment and other income 153 88 1 5 — 94 — 247 Total revenues $ 40,734 $ 5,252 $ 2,004 $ 15,953 $ (324 ) $ 22,885 $ (13,297 ) $ 50,322 Earnings from operations $ 2,391 $ 513 $ 414 $ 770 $ — $ 1,697 $ — $ 4,088 Interest expense — — — — — — (294 ) (294 ) Earnings before income taxes $ 2,391 $ 513 $ 414 $ 770 $ — $ 1,697 $ (294 ) $ 3,794 Three Months Ended September 30, 2016 Revenues - unaffiliated customers: Premiums $ 35,137 $ 1,005 $ — $ — $ — $ 1,005 $ — $ 36,142 Products — 12 30 6,654 — 6,696 — 6,696 Services 1,907 604 617 136 — 1,357 — 3,264 Total revenues - unaffiliated customers 37,044 1,621 647 6,790 — 9,058 — 46,102 Total revenues - affiliated customers — 2,656 1,177 8,445 (275 ) 12,003 (12,003 ) — Investment and other income 133 55 1 2 — 58 — 191 Total revenues $ 37,177 $ 4,332 $ 1,825 $ 15,237 $ (275 ) $ 21,119 $ (12,003 ) $ 46,293 Earnings from operations $ 2,113 $ 404 $ 371 $ 692 $ — $ 1,467 $ — $ 3,580 Interest expense — — — — — — (269 ) (269 ) Earnings before income taxes $ 2,113 $ 404 $ 371 $ 692 $ — $ 1,467 $ (269 ) $ 3,311 Optum (in millions) UnitedHealthcare OptumHealth OptumInsight OptumRx Optum Eliminations Optum Corporate and Eliminations Consolidated Nine Months Ended September 30, 2017 Revenues - unaffiliated customers: Premiums $ 115,295 $ 2,780 $ — $ — $ — $ 2,780 $ — $ 118,075 Products — 33 69 19,107 — 19,209 — 19,209 Services 5,885 2,769 2,011 424 — 5,204 — 11,089 Total revenues - unaffiliated customers 121,180 5,582 2,080 19,531 — 27,193 — 148,373 Total revenues - affiliated customers — 9,294 3,757 27,196 (894 ) 39,353 (39,353 ) — Investment and other income 478 231 3 13 — 247 — 725 Total revenues $ 121,658 $ 15,107 $ 5,840 $ 46,740 $ (894 ) $ 66,793 $ (39,353 ) $ 149,098 Earnings from operations $ 6,736 $ 1,267 $ 1,080 $ 2,149 $ — $ 4,496 $ — $ 11,232 Interest expense — — — — — — (878 ) (878 ) Earnings before income taxes $ 6,736 $ 1,267 $ 1,080 $ 2,149 $ — $ 4,496 $ (878 ) $ 10,354 Nine Months Ended September 30, 2016 Revenues - unaffiliated customers: Premiums $ 104,641 $ 2,725 $ — $ — $ — $ 2,725 $ — $ 107,366 Products 1 36 67 19,595 — 19,698 — 19,699 Services 5,569 1,813 1,862 429 — 4,104 — 9,673 Total revenues - unaffiliated customers 110,211 4,574 1,929 20,024 — 26,527 — 136,738 Total revenues - affiliated customers — 7,682 3,324 24,554 (806 ) 34,754 (34,754 ) — Investment and other income 422 139 1 5 — 145 — 567 Total revenues $ 110,633 $ 12,395 $ 5,254 $ 44,583 $ (806 ) $ 61,426 $ (34,754 ) $ 137,305 Earnings from operations $ 5,909 $ 1,008 $ 950 $ 1,876 $ — $ 3,834 $ — $ 9,743 Interest expense — — — — — — (799 ) (799 ) Earnings before income taxes $ 5,909 $ 1,008 $ 950 $ 1,876 $ — $ 3,834 $ (799 ) $ 8,944

Basis of Presentation Basis of

Basis of Presentation Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2017
Basis of presentation [Abstract]
Basis of Accounting, Policy [Policy Text Block]	The Company has prepared the Condensed Consolidated Financial Statements according to U.S. Generally Accepted Accounting Principles (GAAP) and has included the accounts of UnitedHealth Group and its subsidiaries. The year-end condensed consolidated balance sheet was derived from audited financial statements, but does not include all disclosures required by GAAP. In accordance with the rules and regulations of the U.S. Securities and Exchange Commission (SEC), the Company has omitted certain footnote disclosures that would substantially duplicate the disclosures contained in its annual audited Consolidated Financial Statements. Therefore, these Condensed Consolidated Financial Statements should be read together with the Consolidated Financial Statements and the Notes included in Part II, Item 8, “Financial Statements” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 as filed with the SEC ( 2016 10-K). The accompanying Condensed Consolidated Financial Statements include all normal recurring adjustments necessary to present the interim financial statements fairly.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates These Condensed Consolidated Financial Statements include certain amounts based on the Company’s best estimates and judgments. The Company’s most significant estimates relate to estimates and judgments for medical costs payable and revenues, valuation and impairment analysis of goodwill and other intangible assets and valuations of certain investments. Certain of these estimates require the application of complex assumptions and judgments, often because they involve matters that are inherently uncertain and will likely change in subsequent periods. The impact of any change in estimates is included in earnings in the period in which the estimate is adjusted.
Revenue Recognition, Policy [Policy Text Block]	Revenues The Company’s revenues include premium, product, and service revenues. Service revenues include net patient service revenues that are recorded based upon established billing rates, less allowances for contractual adjustments, and are recognized as services are provided. For more information about the Company’s revenues, see Notes 2 and 13 of Notes to the Consolidated Financial Statements in Part II, Item 8, “Financial Statements” in the 2016 10-K. See Note 9 for disaggregation of revenue by segment and type. As of September 30, 2017 , accounts receivables related to products and services were $3.5 billion . For the three and nine months ended September 30, 2017 , the Company had no material bad-debt expense and there were no material contract assets, contract liabilities or deferred contract costs recorded on the Condensed Consolidated Balance Sheet as of September 30, 2017 . For the three and nine months ended September 30, 2017 , 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 that have 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.
Health Insurance Industry Tax, Accounting Policy [Policy Text Block]	Health Insurance Industry Tax The Patient Protection and Affordable Care Act (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. A provision in the 2016 Federal Budget imposed a one year moratorium for 2017 on the collection of the Health Insurance Industry Tax. The Company has experienced a lower effective income tax rate in 2017 as compared to 2016 primarily due to the moratorium.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) No. 2016-02, “Leases (Topic 842)” (ASU 2016-02). Under ASU 2016-02, an entity will be required to recognize assets and liabilities for the rights and obligations created by leases on the entity’s balance sheet for both finance and operating leases. For leases with a term of 12 months or less, an entity can elect to not recognize lease assets and lease liabilities and expense the lease over a straight-line basis for the term of the lease. ASU 2016-02 will require new disclosures that depict the amount, timing and uncertainty of cash flows pertaining to an entity’s leases. Companies are required to adopt the new standard using a modified retrospective approach for annual and interim periods beginning after December 15, 2018. Early adoption of ASU 2016-02 is permitted. When adopted, the Company does not expect ASU 2016-02 to have a material impact on its results of operations, equity or cash flows. The impact of ASU 2016-02 on the Company’s consolidated financial position will be based on leases outstanding at the time of adoption. In January 2016, the FASB issued ASU 2016-01, “Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities” (ASU 2016-01). The new guidance changes the current accounting related to (i) the classification and measurement of certain equity investments, (ii) the presentation of changes in the fair value of financial liabilities measured under the fair value option that are due to instrument-specific credit risk, and (iii) certain disclosures associated with the fair value of financial instruments. Most notably, ASU 2016-01 requires that equity investments, with certain exemptions, be measured at fair value with changes in fair value recognized in net income as opposed to other comprehensive income. The new guidance is effective for annual and interim reporting periods beginning after December 15, 2017. As of September 30, 2017 , based on equity securities held, the Company does not expect ASU 2016-01 to have a material impact on its consolidated financial position, results of operations, equity or cash flows. The Company will continue to evaluate any changes in its mix of investments or market conditions and the related impact of ASU 2016-01. Recently Adopted Accounting Standards In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” as modified by subsequently issued ASUs 2015-14, 2016-08, 2016-10, 2016-12 and 2016-20 (collectively ASU 2014-09). ASU 2014-09 superseded existing revenue recognition standards with a single model unless those contracts are within the scope of other standards (e.g., an insurance entity’s insurance contracts). The revenue recognition principle in ASU 2014-09 is that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The Company early adopted the new standard effective January 1, 2017, as allowed, using the modified retrospective approach. A significant majority of the Company’s revenues are not subject to the new guidance. The adoption of ASU 2014-09 did not have a material impact on the Company’s consolidated financial position, results of operations, equity or cash flows as of the adoption date or for the nine months ended September 30, 2017 . The Company has included the disclosures required by ASU 2014-09 above. The Company has determined that there have been no other recently adopted or issued accounting standards that had, or will have, a material impact on its Condensed Consolidated Financial Statements.

Investments Investments (Polici

Investments Investments (Policies)	9 Months Ended
	Sep. 30, 2017
Investment [Line Items]
Investment, Policy [Policy Text Block]	At each reporting period, the Company evaluates securities for impairment when the fair value of the investment is less than its amortized cost. The Company evaluated the underlying credit quality and credit ratings of the issuers, noting no significant deterioration since purchase. As of September 30, 2017 , 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.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Short-Term and Long-Term Investments [Table Text Block]	A summary of short-term and long-term investments by major security type is as follows: (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value September 30, 2017 Debt securities - available-for-sale: U.S. government and agency obligations $ 2,708 $ 3 $ (24 ) $ 2,687 State and municipal obligations 6,997 117 (20 ) 7,094 Corporate obligations 13,092 88 (26 ) 13,154 U.S. agency mortgage-backed securities 3,946 13 (28 ) 3,931 Non-U.S. agency mortgage-backed securities 1,018 5 (4 ) 1,019 Total debt securities - available-for-sale 27,761 226 (102 ) 27,885 Equity securities 1,949 30 (38 ) 1,941 Debt securities - held-to-maturity: U.S. government and agency obligations 259 — — 259 State and municipal obligations 4 — — 4 Corporate obligations 285 — — 285 Total debt securities - held-to-maturity 548 — — 548 Total investments $ 30,258 $ 256 $ (140 ) $ 30,374 December 31, 2016 Debt securities - available-for-sale: U.S. government and agency obligations $ 2,294 $ 1 $ (31 ) $ 2,264 State and municipal obligations 7,120 40 (101 ) 7,059 Corporate obligations 10,944 41 (58 ) 10,927 U.S. agency mortgage-backed securities 2,963 7 (43 ) 2,927 Non-U.S. agency mortgage-backed securities 1,009 3 (10 ) 1,002 Total debt securities - available-for-sale 24,330 92 (243 ) 24,179 Equity securities 2,036 52 (47 ) 2,041 Debt securities - held-to-maturity: U.S. government and agency obligations 250 1 — 251 State and municipal obligations 5 — — 5 Corporate obligations 238 — — 238 Total debt securities - held-to-maturity 493 1 — 494 Total investments $ 26,859 $ 145 $ (290 ) $ 26,714
Investments by Contractual Maturity [Table Text Block]	The amortized cost and fair value of debt securities as of September 30, 2017 , by contractual maturity, were as follows: Available-for-Sale Held-to-Maturity (in millions) Amortized Cost Fair Value Amortized Fair Due in one year or less $ 3,650 $ 3,651 $ 165 $ 165 Due after one year through five years 10,607 10,645 125 125 Due after five years through ten years 6,476 6,540 113 113 Due after ten years 2,064 2,099 145 145 U.S. agency mortgage-backed securities 3,946 3,931 — — Non-U.S. agency mortgage-backed securities 1,018 1,019 — — Total debt securities $ 27,761 $ 27,885 $ 548 $ 548
Fair Value of Available-for-Sale Investments with Gross Unrealized Losses by Investment Type and Length of Time that Individual Securities have been in a Continuous Unrealized Loss Position [Table Text Block]	The fair value of available-for-sale investments with gross unrealized losses by major security type and length of time that individual securities have been in a continuous unrealized loss position were as follows: Less Than 12 Months 12 Months or Greater Total (in millions) Fair Value Gross Unrealized Losses Fair Value Gross Fair Value Gross September 30, 2017 Debt securities - available-for-sale: U.S. government and agency obligations $ 1,635 $ (11 ) $ 532 $ (13 ) $ 2,167 $ (24 ) State and municipal obligations 1,910 (15 ) 429 (5 ) 2,339 (20 ) Corporate obligations 3,958 (17 ) 496 (9 ) 4,454 (26 ) U.S. agency mortgage-backed securities 2,233 (24 ) 146 (4 ) 2,379 (28 ) Non-U.S. agency mortgage-backed securities 351 (3 ) 49 (1 ) 400 (4 ) Total debt securities - available-for-sale $ 10,087 $ (70 ) $ 1,652 $ (32 ) $ 11,739 $ (102 ) Equity securities $ 59 $ (4 ) $ 97 $ (34 ) $ 156 $ (38 ) December 31, 2016 Debt securities - available-for-sale: U.S. government and agency obligations $ 1,794 $ (31 ) $ — $ — $ 1,794 $ (31 ) State and municipal obligations 4,376 (101 ) — — 4,376 (101 ) Corporate obligations 5,128 (56 ) 137 (2 ) 5,265 (58 ) U.S. agency mortgage-backed securities 2,247 (40 ) 79 (3 ) 2,326 (43 ) Non-U.S. agency mortgage-backed securities 544 (7 ) 97 (3 ) 641 (10 ) Total debt securities - available-for-sale $ 14,089 $ (235 ) $ 313 $ (8 ) $ 14,402 $ (243 ) Equity securities $ 93 $ (5 ) $ 91 $ (42 ) $ 184 $ (47 )

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table presents a summary of fair value measurements by level and carrying values for items measured at fair value on a recurring basis in the Condensed Consolidated Balance Sheets: (in millions) Quoted Prices in Active Markets (Level 1) Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Total Fair and Carrying Value September 30, 2017 Cash and cash equivalents $ 13,462 $ 2,807 $ — $ 16,269 Debt securities - available-for-sale: U.S. government and agency obligations 2,405 282 — 2,687 State and municipal obligations — 7,094 — 7,094 Corporate obligations 73 12,947 134 13,154 U.S. agency mortgage-backed securities — 3,931 — 3,931 Non-U.S. agency mortgage-backed securities — 1,019 — 1,019 Total debt securities - available-for-sale 2,478 25,273 134 27,885 Equity securities 1,804 14 123 1,941 Assets under management 763 2,319 — 3,082 Interest rate swap assets — 50 — 50 Total assets at fair value $ 18,507 $ 30,463 $ 257 $ 49,227 Percentage of total assets at fair value 37 % 62 % 1 % 100 % Interest rate swap liabilities $ — $ 12 $ — $ 12 December 31, 2016 Cash and cash equivalents $ 10,386 $ 44 $ — $ 10,430 Debt securities - available-for-sale: U.S. government and agency obligations 2,017 247 — 2,264 State and municipal obligations — 7,059 — 7,059 Corporate obligations 21 10,804 102 10,927 U.S. agency mortgage-backed securities — 2,927 — 2,927 Non-U.S. agency mortgage-backed securities — 1,002 — 1,002 Total debt securities - available-for-sale 2,038 22,039 102 24,179 Equity securities 1,591 13 437 2,041 Assets under management 1,064 2,041 — 3,105 Interest rate swap assets — 55 — 55 Total assets at fair value $ 15,079 $ 24,192 $ 539 $ 39,810 Percentage of total assets at fair value 38 % 61 % 1 % 100 % Interest rate swap liabilities $ — $ 14 $ — $ 14
Fair Value Measurements, Nonrecurring [Table Text Block]	The following table presents a summary of fair value measurements by level and carrying values for certain financial instruments not measured at fair value on a recurring basis in the Condensed Consolidated Balance Sheets: (in millions) Quoted Prices in Active Markets (Level 1) Other Observable Inputs (Level 2) Unobservable Inputs (Level 3) Total Fair Value Total Carrying Value September 30, 2017 Debt securities - held-to-maturity: U.S. government and agency obligations $ 256 $ 3 $ — $ 259 $ 259 State and municipal obligations — — 4 4 4 Corporate obligations 17 1 267 285 285 Total debt securities - held-to-maturity $ 273 $ 4 $ 271 $ 548 $ 548 Other assets $ — $ 477 $ — $ 477 $ 475 Long-term debt and other financing obligations $ — $ 31,686 $ — $ 31,686 $ 28,959 December 31, 2016 Debt securities - held-to-maturity: U.S. government and agency obligations $ 251 $ — $ — $ 251 $ 250 State and municipal obligations — — 5 5 5 Corporate obligations 20 8 210 238 238 Total debt securities - held-to-maturity $ 271 $ 8 $ 215 $ 494 $ 493 Other assets $ — $ 476 $ — $ 476 $ 471 Long-term debt and other financing obligations $ — $ 31,295 $ — $ 31,295 $ 29,337

Medical Costs Payable (Tables)

Medical Costs Payable (Tables)	9 Months Ended
	Sep. 30, 2016
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 nine months ended September 30: (in millions) 2017 2016 Medical costs payable, beginning of period $ 16,391 $ 14,330 Acquisitions 76 — Reported medical costs: Current year 97,519 87,532 Prior years (690 ) (190 ) Total reported medical costs 96,829 87,342 Medical payments: Payments for current year (81,237 ) (72,092 ) Payments for prior years (14,096 ) (13,080 ) Total medical payments (95,333 ) (85,172 ) Medical costs payable, end of period $ 17,963 $ 16,500

Commercial Paper and Long-Ter22

Commercial Paper and Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Instrument [Line Items]
Commercial Paper and Long-Term Debt [Table Text Block]	Commercial paper and senior unsecured long-term debt consisted of the following: September 30, 2017 December 31, 2016 (in millions, except percentages) Par Carrying Value Fair Value Par Value Carrying Fair Value Commercial paper $ 304 $ 303 $ 303 $ 3,633 $ 3,633 $ 3,633 Floating rate notes due January 2017 — — — 750 750 750 6.000% notes due June 2017 — — — 441 446 450 1.450% notes due July 2017 — — — 750 750 751 1.400% notes due October 2017 625 625 625 625 624 626 6.000% notes due November 2017 156 157 157 156 159 163 1.400% notes due December 2017 750 750 750 750 751 750 6.000% notes due February 2018 1,100 1,102 1,118 1,100 1,107 1,153 1.900% notes due July 2018 1,500 1,498 1,504 1,500 1,496 1,507 1.700% notes due February 2019 750 749 750 750 748 748 1.625% notes due March 2019 500 501 499 500 501 498 2.300% notes due December 2019 500 497 504 500 498 504 2.700% notes due July 2020 1,500 1,496 1,530 1,500 1,495 1,523 3.875% notes due October 2020 450 449 473 450 450 474 4.700% notes due February 2021 400 407 431 400 409 433 2.125% notes due March 2021 750 746 750 750 745 741 3.375% notes due November 2021 500 497 520 500 497 519 2.875% notes due December 2021 750 748 769 750 748 760 2.875% notes due March 2022 1,100 1,063 1,125 1,100 1,057 1,114 3.350% notes due July 2022 1,000 996 1,044 1,000 995 1,030 0.000% notes due November 2022 15 11 12 15 11 12 2.750% notes due February 2023 625 612 632 625 609 622 2.875% notes due March 2023 750 771 765 750 771 753 3.750% notes due July 2025 2,000 1,987 2,122 2,000 1,986 2,070 3.100% notes due March 2026 1,000 995 1,012 1,000 994 986 3.450% notes due January 2027 750 745 776 750 745 762 3.375% notes due April 2027 625 618 643 — — — 4.625% notes due July 2035 1,000 991 1,146 1,000 991 1,090 5.800% notes due March 2036 850 837 1,071 850 837 1,034 6.500% notes due June 2037 500 491 683 500 491 643 6.625% notes due November 2037 650 641 903 650 640 850 6.875% notes due February 2038 1,100 1,075 1,561 1,100 1,075 1,497 5.700% notes due October 2040 300 296 383 300 296 366 5.950% notes due February 2041 350 345 460 350 345 437 4.625% notes due November 2041 600 588 673 600 588 634 4.375% notes due March 2042 502 483 543 502 483 509 3.950% notes due October 2042 625 607 641 625 606 609 4.250% notes due March 2043 750 734 801 750 734 765 4.750% notes due July 2045 2,000 1,972 2,310 2,000 1,972 2,203 4.200% notes due January 2047 750 738 799 750 737 759 4.250% notes due April 2047 725 717 777 — — — Total commercial paper and long-term debt $ 29,102 $ 28,838 $ 31,565 $ 33,022 $ 32,770 $ 34,728
Schedule of Subsequent Events [Table Text Block]	In October 2017, the Company issued $4.0 billion of senior unsecured notes consisting of the following: (in millions, except percentages) Par Floating rate notes due October 2020 $ 300 1.950% notes due October 2020 900 2.375% notes due October 2022 900 2.950% notes due October 2027 950 3.750% notes due October 2047 950

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Class of Stock [Line Items]
Dividends Declared [Table Text Block]	The following table provides details of the Company’s 2017 dividend payments: Payment Date Amount per Share Total Amount Paid (in millions) March 10, 2017 $ 0.625 $ 596 June 27, 2017 0.750 724 September 19, 2017 0.750 726

Segment Financial Information24

Segment Financial Information (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segment Financial Information [Table Text Block]	The following tables present reportable segment financial information: Optum (in millions) UnitedHealthcare OptumHealth OptumInsight OptumRx Optum Eliminations Optum Corporate and Eliminations Consolidated Three Months Ended September 30, 2017 Revenues - unaffiliated customers: Premiums $ 38,576 $ 976 $ — $ — $ — $ 976 $ — $ 39,552 Products — 10 29 6,626 — 6,665 — 6,665 Services 2,005 1,040 677 136 — 1,853 — 3,858 Total revenues - unaffiliated customers 40,581 2,026 706 6,762 — 9,494 — 50,075 Total revenues - affiliated customers — 3,138 1,297 9,186 (324 ) 13,297 (13,297 ) — Investment and other income 153 88 1 5 — 94 — 247 Total revenues $ 40,734 $ 5,252 $ 2,004 $ 15,953 $ (324 ) $ 22,885 $ (13,297 ) $ 50,322 Earnings from operations $ 2,391 $ 513 $ 414 $ 770 $ — $ 1,697 $ — $ 4,088 Interest expense — — — — — — (294 ) (294 ) Earnings before income taxes $ 2,391 $ 513 $ 414 $ 770 $ — $ 1,697 $ (294 ) $ 3,794 Three Months Ended September 30, 2016 Revenues - unaffiliated customers: Premiums $ 35,137 $ 1,005 $ — $ — $ — $ 1,005 $ — $ 36,142 Products — 12 30 6,654 — 6,696 — 6,696 Services 1,907 604 617 136 — 1,357 — 3,264 Total revenues - unaffiliated customers 37,044 1,621 647 6,790 — 9,058 — 46,102 Total revenues - affiliated customers — 2,656 1,177 8,445 (275 ) 12,003 (12,003 ) — Investment and other income 133 55 1 2 — 58 — 191 Total revenues $ 37,177 $ 4,332 $ 1,825 $ 15,237 $ (275 ) $ 21,119 $ (12,003 ) $ 46,293 Earnings from operations $ 2,113 $ 404 $ 371 $ 692 $ — $ 1,467 $ — $ 3,580 Interest expense — — — — — — (269 ) (269 ) Earnings before income taxes $ 2,113 $ 404 $ 371 $ 692 $ — $ 1,467 $ (269 ) $ 3,311 Optum (in millions) UnitedHealthcare OptumHealth OptumInsight OptumRx Optum Eliminations Optum Corporate and Eliminations Consolidated Nine Months Ended September 30, 2017 Revenues - unaffiliated customers: Premiums $ 115,295 $ 2,780 $ — $ — $ — $ 2,780 $ — $ 118,075 Products — 33 69 19,107 — 19,209 — 19,209 Services 5,885 2,769 2,011 424 — 5,204 — 11,089 Total revenues - unaffiliated customers 121,180 5,582 2,080 19,531 — 27,193 — 148,373 Total revenues - affiliated customers — 9,294 3,757 27,196 (894 ) 39,353 (39,353 ) — Investment and other income 478 231 3 13 — 247 — 725 Total revenues $ 121,658 $ 15,107 $ 5,840 $ 46,740 $ (894 ) $ 66,793 $ (39,353 ) $ 149,098 Earnings from operations $ 6,736 $ 1,267 $ 1,080 $ 2,149 $ — $ 4,496 $ — $ 11,232 Interest expense — — — — — — (878 ) (878 ) Earnings before income taxes $ 6,736 $ 1,267 $ 1,080 $ 2,149 $ — $ 4,496 $ (878 ) $ 10,354 Nine Months Ended September 30, 2016 Revenues - unaffiliated customers: Premiums $ 104,641 $ 2,725 $ — $ — $ — $ 2,725 $ — $ 107,366 Products 1 36 67 19,595 — 19,698 — 19,699 Services 5,569 1,813 1,862 429 — 4,104 — 9,673 Total revenues - unaffiliated customers 110,211 4,574 1,929 20,024 — 26,527 — 136,738 Total revenues - affiliated customers — 7,682 3,324 24,554 (806 ) 34,754 (34,754 ) — Investment and other income 422 139 1 5 — 145 — 567 Total revenues $ 110,633 $ 12,395 $ 5,254 $ 44,583 $ (806 ) $ 61,426 $ (34,754 ) $ 137,305 Earnings from operations $ 5,909 $ 1,008 $ 950 $ 1,876 $ — $ 3,834 $ — $ 9,743 Interest expense — — — — — — (799 ) (799 ) Earnings before income taxes $ 5,909 $ 1,008 $ 950 $ 1,876 $ — $ 3,834 $ (799 ) $ 8,944

Basis of Presentation Basis o25

Basis of Presentation Basis of Presentation, Uses of Estimates and Significant Accounting Policies (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Accounts Receivable, Net	$ 8,638	$ 8,152
Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncement or Change in Accounting Principle, Description of Transition Method	Modified Retrospective
New Accounting Pronouncement, Transition Guidance Not Significant or Not Practical	Impact is not material
Products and Services [Domain]
Accounts Receivable, Net	$ 3,500

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Millions	Sep. 30, 2017USD ($)positions
Investment [Line Items]
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | positions	9,000
Total number of security positions	29,000
Equity Method Investments | $	$ 854

Investments (Short-Term and Lon

Investments (Short-Term and Long-Term Investments) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	$ 27,761	$ 24,330
Securities, Available for sale Debt Securities, Gross Unrealized Gains	226	92
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(102)	(243)
Available-for-sale Securities, Debt Securities	27,885	24,179
Equity Securities, Amortized Cost Basis	1,949	2,036
Equity Securities, Gross Unrealized Gains	30	52
Equity Securities, Gross Unrealized Losses	(38)	(47)
Equity Securities, Fair Value	1,941	2,041
Held-to-maturity securities, Amortized Cost	548	493
Securities, Held to maturity, Unrecognized Holding Gain	0	1
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held-to-maturity Securities, Fair Value	548	494
Total investments, Amortized Cost	30,258	26,859
Total investments, Gross Unrealized Gains	256	145
Total investments, Gross Unrealized Losses	(140)	(290)
Investments, Fair Value Disclosure	30,374	26,714
Debt Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale Securities, Debt Securities	27,885	24,179
U.S. Government and Agency Obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	2,708	2,294
Securities, Available for sale Debt Securities, Gross Unrealized Gains	3	1
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(24)	(31)
Available-for-sale Securities, Debt Securities	2,687	2,264
Held-to-maturity securities, Amortized Cost	259	250
Securities, Held to maturity, Unrecognized Holding Gain	0	1
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held-to-maturity Securities, Fair Value	259	251
State and Municipal Obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	6,997	7,120
Securities, Available for sale Debt Securities, Gross Unrealized Gains	117	40
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(20)	(101)
Available-for-sale Securities, Debt Securities	7,094	7,059
Held-to-maturity securities, Amortized Cost	4	5
Securities, Held to maturity, Unrecognized Holding Gain	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held-to-maturity Securities, Fair Value	4	5
Corporate Obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	13,092	10,944
Securities, Available for sale Debt Securities, Gross Unrealized Gains	88	41
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(26)	(58)
Available-for-sale Securities, Debt Securities	13,154	10,927
Held-to-maturity securities, Amortized Cost	285	238
Securities, Held to maturity, Unrecognized Holding Gain	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held-to-maturity Securities, Fair Value	285	238
U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	3,946	2,963
Securities, Available for sale Debt Securities, Gross Unrealized Gains	13	7
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(28)	(43)
Available-for-sale Securities, Debt Securities	3,931	2,927
Non-U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	1,018	1,009
Securities, Available for sale Debt Securities, Gross Unrealized Gains	5	3
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(4)	(10)
Available-for-sale Securities, Debt Securities	$ 1,019	$ 1,002

Investments (Amortized Cost and

Investments (Amortized Cost and Fair Value of Available-for-Sale Debt Securities by Contractual Maturity) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Due in one year or less, Amortized Cost	$ 3,650
Due after one year through five years, Amortized Cost	10,607
Due after five years through ten years, Amortized Cost	6,476
Due after ten years, Amortized Cost	2,064
Total debt securities - available-for-sale, Amortized Cost	27,761	$ 24,330
Due in one year or less, Fair Value	3,651
Due after one year through five years, Fair Value	10,645
Due after five years through ten years, Fair Value	6,540
Due after ten years, Fair Value	2,099
Available-for-sale Securities, Debt Securities	27,885	24,179
Held-to-maturity Securities, Debt Maturities, within One Year, Net Carrying Amount	165
Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount	125
Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount	113
Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount	145
Held-to-maturity securities, Amortized Cost	548	493
Held-to-maturity Securities, Debt Maturities, within One Year, Fair Value	165
Held-to-maturity Securities, Debt Maturities, Year Two Through Five, Fair Value	125
Held-to-maturity Securities, Debt Maturities, Year Six Through Ten, Fair Value	113
Held-to-maturity Securities, Debt Maturities, after Ten Years, Fair Value	145
Held-to-maturity Securities, Fair Value	548	494
U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Mortgage-backed securities, Amortized Cost	3,946
Total debt securities - available-for-sale, Amortized Cost	3,946	2,963
Mortgage-backed securities, Fair Value	3,931
Available-for-sale Securities, Debt Securities	3,931	2,927
Non-U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Mortgage-backed securities, Amortized Cost	1,018
Total debt securities - available-for-sale, Amortized Cost	1,018	1,009
Mortgage-backed securities, Fair Value	1,019
Available-for-sale Securities, Debt Securities	$ 1,019	$ 1,002

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	Sep. 30, 2017	Dec. 31, 2016
Debt Securities [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	$ 10,087	$ 14,089
Less Than 12 Months, Gross Unrealized Losses	(70)	(235)
Greater Than 12 Months, Fair Value	1,652	313
Greater Than 12 Months, Gross Unrealized Losses	(32)	(8)
Total, Fair Value	11,739	14,402
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(102)	(243)
U.S. Government and Agency Obligations [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	1,635	1,794
Less Than 12 Months, Gross Unrealized Losses	(11)	(31)
Greater Than 12 Months, Fair Value	532
Greater Than 12 Months, Gross Unrealized Losses	(13)
Total, Fair Value	2,167	1,794
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(24)	(31)
State and Municipal Obligations [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	1,910	4,376
Less Than 12 Months, Gross Unrealized Losses	(15)	(101)
Greater Than 12 Months, Fair Value	429
Greater Than 12 Months, Gross Unrealized Losses	(5)
Total, Fair Value	2,339	4,376
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(20)	(101)
Corporate Obligations [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	3,958	5,128
Less Than 12 Months, Gross Unrealized Losses	(17)	(56)
Greater Than 12 Months, Fair Value	496	137
Greater Than 12 Months, Gross Unrealized Losses	(9)	(2)
Total, Fair Value	4,454	5,265
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(26)	(58)
U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	2,233	2,247
Less Than 12 Months, Gross Unrealized Losses	(24)	(40)
Greater Than 12 Months, Fair Value	146	79
Greater Than 12 Months, Gross Unrealized Losses	(4)	(3)
Total, Fair Value	2,379	2,326
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(28)	(43)
Non-U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	351	544
Less Than 12 Months, Gross Unrealized Losses	(3)	(7)
Greater Than 12 Months, Fair Value	49	97
Greater Than 12 Months, Gross Unrealized Losses	(1)	(3)
Total, Fair Value	400	641
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(4)	(10)
Equity Securities [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	59	93
Less Than 12 Months, Gross Unrealized Losses	(4)	(5)
Greater Than 12 Months, Fair Value	97	91
Greater Than 12 Months, Gross Unrealized Losses	(34)	(42)
Total, Fair Value	156	184
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (38)	$ (47)

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Fair Value [Line Items]
Transfers from level 1 to level 2-Assets	$ 0	$ 0
Transfers from level 1 to level 2-Liabilities	0	0
Transfer from level 2 to level 1-Assets	0	0
Transfer from level 2 to level 1-Liabilities	0	0
Transfers Into Level 3	0	0
Transfers out of Level 3	0	0
Fair Value, Measurements, Nonrecurring [Member]
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	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 16,269	$ 10,430
Available-for-sale Securities, Debt Securities	27,885	24,179
Equity Securities, Fair Value	1,941	2,041
AARP Assets Under Management	3,082	3,105
Interest rate swap assets	50	55
Total assets at fair value	49,227	39,810
Interest rate swap liabilities	12	14
Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	27,885	24,179
U.S. Government and Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	2,687	2,264
State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	7,094	7,059
Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	13,154	10,927
U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	3,931	2,927
Non-U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	1,019	1,002
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	13,462	10,386
Equity Securities, Fair Value	1,804	1,591
AARP Assets Under Management	763	1,064
Interest rate swap assets	0	0
Total assets at fair value	18,507	15,079
Interest rate swap liabilities	0	0
Quoted Prices in Active Markets (Level 1) [Member] | Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	2,478	2,038
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]
Available-for-sale Securities, Debt Securities	2,405	2,017
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]
Available-for-sale Securities, Debt Securities	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]
Available-for-sale Securities, Debt Securities	73	21
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]
Available-for-sale Securities, Debt Securities	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]
Available-for-sale Securities, Debt Securities	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	2,807	44
Equity Securities, Fair Value	14	13
AARP Assets Under Management	2,319	2,041
Interest rate swap assets	50	55
Total assets at fair value	30,463	24,192
Interest rate swap liabilities	12	14
Other Observable Inputs (Level 2) [Member] | Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	25,273	22,039
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]
Available-for-sale Securities, Debt Securities	282	247
Other Observable Inputs (Level 2) [Member] | State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	7,094	7,059
Other Observable Inputs (Level 2) [Member] | Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	12,947	10,804
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]
Available-for-sale Securities, Debt Securities	3,931	2,927
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]
Available-for-sale Securities, Debt Securities	1,019	1,002
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, Fair Value	123	437
AARP Assets Under Management	0	0
Interest rate swap assets	0	0
Total assets at fair value	257	539
Interest rate swap liabilities	0	0
Unobservable Inputs (Level 3) [Member] | Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	134	102
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]
Available-for-sale Securities, Debt Securities	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]
Available-for-sale Securities, Debt Securities	0	0
Unobservable Inputs (Level 3) [Member] | Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Debt Securities	134	102
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]
Available-for-sale Securities, Debt Securities	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]
Available-for-sale Securities, Debt Securities	$ 0	$ 0

Fair Value (Financial Assets 32

Fair Value (Financial Assets and Liabilities, Not Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	$ 548	$ 494
Held-to-maturity Securities	548	493
Debt and other financing obligations	31,565	34,728
Debt and other financing obligations, carrying value	28,838	32,770
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	548	494
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	273	271
Fair Value, Measurements, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	4	8
Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	271	215
U.S. Government and Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities	259	250
U.S. Government and Agency Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	259	251
U.S. Government and Agency Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	256	251
U.S. Government and Agency Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	3	0
U.S. Government and Agency Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	0	0
State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities	4	5
State and Municipal Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	4	5
State and Municipal Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	0	0
State and Municipal Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	0	0
State and Municipal Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	4	5
Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities	285	238
Corporate Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	285	238
Corporate Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	17	20
Corporate Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	1	8
Corporate Obligations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Held-to-maturity Securities, Fair Value	267	210
Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Assets	475	471
Other Assets [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Assets, Fair Value Disclosure	477	476
Other Assets [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Assets, Fair Value Disclosure	0	0
Other Assets [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Assets, Fair Value Disclosure	477	476
Other Assets [Member] | Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other Assets, Fair Value Disclosure	0	0
Long-term debt and other financing obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations, carrying value	28,959	29,337
Long-term debt and other financing obligations | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt and other financing obligations	31,686	31,295
Long-term debt and other financing obligations | Fair Value, Measurements, 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 | Fair Value, Measurements, 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	31,686	31,295
Long-term debt and other financing obligations | Fair Value, Measurements, 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

Other Current Receivables (Deta

Other Current Receivables (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other current receivables	$ 6,826	$ 7,499
Pharmaceutical manufacturer rebates receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other current receivables	$ 4,000	$ 3,300

Medical Costs Payable (Narrativ

Medical Costs Payable (Narrative) (Details) - USD ($) $ in Billions	Sep. 30, 2017	Dec. 31, 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred but Not Reported (IBNR) Claims, Amount	$ 12.4	$ 11.6

Medical Costs Payable Rollforwa

Medical Costs Payable Rollforward (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Medical costs payable, beginning of period	$ 16,391	$ 14,330
Acquisitions	76	0
Reported medical costs:
Current year	97,519	87,532
Prior years	(690)	(190)
Total reported medical costs	96,829	87,342
Medical payments:
Payments for current year	(81,237)	(72,092)
Payments for prior years	(14,096)	(13,080)
Total medical payments	(95,333)	(85,172)
Medical costs payable, end of period	$ 17,963	$ 16,500

Commercial Paper and Long-Ter36

Commercial Paper and Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Oct. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 29,102		$ 33,022
Repayments of Assumed Debt	$ 926
Commercial Paper [Member]
Debt Instrument [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time	1.40%
Five Year $3.0 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	$ 3,000
Line of Credit Facility, Expiration Period	5 years
Five Year $3.0 Billion Credit Facility [Member] | Minimum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period	2.00%
Five Year $3.0 Billion Credit Facility [Member] | Maximum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period	2.30%
Three Year 2.0 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	$ 2,000
Line of Credit Facility, Expiration Period	3 years
Three Year 2.0 Billion Credit Facility [Member] | Minimum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period	2.00%
Three Year 2.0 Billion Credit Facility [Member] | Maximum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period	2.30%
364 Day $1.0 Billion Credit Facility [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit, Current	$ 0
Line of Credit, Credit Facility, Maximum Borrowing Capacity	$ 1,000
Line of Credit Facility, Expiration Period	364 days
364 Day $1.0 Billion Credit Facility [Member] | Minimum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period	2.00%
364 Day $1.0 Billion Credit Facility [Member] | Maximum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period	2.30%
Subsidiaries [Member]
Debt Instrument [Line Items]
Other Long-term Debt	$ 424		200
Other Long-term Debt, Current	$ 104		$ 80
Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 4,000

Commercial Paper and Long-Ter37

Commercial Paper and Long-Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Par Value	$ 29,102	$ 33,022
Carrying Value	28,838	32,770
Fair Value	31,565	34,728
Commercial Paper [Member]
Debt Instrument [Line Items]
Par Value	304	3,633
Carrying Value	303	3,633
Fair Value	303	3,633
Floating rate notes due January 2017 [Member]
Debt Instrument [Line Items]
Par Value	0	750
Unsecured Debt, Current	0	750
Fair Value	$ 0	750
6.000% notes due June 2017 [Member]
Debt Instrument [Line Items]
Interest Rate	6.00%
Par Value	$ 0	441
Unsecured Debt, Current	0	446
Fair Value	$ 0	450
1.450% notes due July 2017 [Member]
Debt Instrument [Line Items]
Interest Rate	1.45%
Par Value	$ 0	750
Unsecured Debt, Current	0	750
Fair Value	$ 0	751
1.400% notes due October 2017 [Member]
Debt Instrument [Line Items]
Interest Rate	1.40%
Par Value	$ 625	625
Unsecured Debt, Current	625	624
Fair Value	$ 625	626
6.000% notes due November 2017 [Member]
Debt Instrument [Line Items]
Interest Rate	6.00%
Par Value	$ 156	156
Unsecured Debt, Current	157	159
Fair Value	$ 157	163
1.400% notes due December 2017 [Member]
Debt Instrument [Line Items]
Interest Rate	1.40%
Par Value	$ 750	750
Unsecured Debt, Current	750	751
Fair Value	$ 750	750
6.000% notes due February 2018 [Member]
Debt Instrument [Line Items]
Interest Rate	6.00%
Par Value	$ 1,100	1,100
Unsecured Long-term Debt, Noncurrent		1,107
Unsecured Debt, Current	1,102
Fair Value	$ 1,118	1,153
1.900% notes due July 2018 [Member]
Debt Instrument [Line Items]
Interest Rate	1.90%
Par Value	$ 1,500	1,500
Unsecured Long-term Debt, Noncurrent		1,496
Unsecured Debt, Current	1,498
Fair Value	$ 1,504	1,507
1.700% Notes due February 2019 [Member]
Debt Instrument [Line Items]
Interest Rate	1.70%
Par Value	$ 750	750
Unsecured Long-term Debt, Noncurrent	749	748
Fair Value	$ 750	748
1.625% notes due March 2019 [Member]
Debt Instrument [Line Items]
Interest Rate	1.625%
Par Value	$ 500	500
Unsecured Long-term Debt, Noncurrent	501	501
Fair Value	$ 499	498
2.300% notes due December 2019 [Member]
Debt Instrument [Line Items]
Interest Rate	2.30%
Par Value	$ 500	500
Unsecured Long-term Debt, Noncurrent	497	498
Fair Value	$ 504	504
2.700% notes due July 2020 [Member]
Debt Instrument [Line Items]
Interest Rate	2.70%
Par Value	$ 1,500	1,500
Unsecured Long-term Debt, Noncurrent	1,496	1,495
Fair Value	$ 1,530	1,523
3.875% notes due October 2020 [Member]
Debt Instrument [Line Items]
Interest Rate	3.875%
Par Value	$ 450	450
Unsecured Long-term Debt, Noncurrent	449	450
Fair Value	$ 473	474
4.700% notes due February 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	4.70%
Par Value	$ 400	400
Unsecured Long-term Debt, Noncurrent	407	409
Fair Value	$ 431	433
2.125% notes due March 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	2.125%
Par Value	$ 750	750
Unsecured Long-term Debt, Noncurrent	746	745
Fair Value	$ 750	741
3.375% notes due November 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	3.375%
Par Value	$ 500	500
Unsecured Long-term Debt, Noncurrent	497	497
Fair Value	$ 520	519
2.875% notes due December 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	2.875%
Par Value	$ 750	750
Unsecured Long-term Debt, Noncurrent	748	748
Fair Value	$ 769	760
2.875% notes due March 2022 [Member]
Debt Instrument [Line Items]
Interest Rate	2.875%
Par Value	$ 1,100	1,100
Unsecured Long-term Debt, Noncurrent	1,063	1,057
Fair Value	$ 1,125	1,114
3.350% notes due July 2022 [Member]
Debt Instrument [Line Items]
Interest Rate	3.35%
Par Value	$ 1,000	1,000
Unsecured Long-term Debt, Noncurrent	996	995
Fair Value	$ 1,044	1,030
0.000% notes due November 2022 [Member]
Debt Instrument [Line Items]
Interest Rate	0.00%
Par Value	$ 15	15
Unsecured Long-term Debt, Noncurrent	11	11
Fair Value	$ 12	12
2.750% notes due February 2023 [Member]
Debt Instrument [Line Items]
Interest Rate	2.75%
Par Value	$ 625	625
Unsecured Long-term Debt, Noncurrent	612	609
Fair Value	$ 632	622
2.875% notes due March 2023 [Member]
Debt Instrument [Line Items]
Interest Rate	2.875%
Par Value	$ 750	750
Unsecured Long-term Debt, Noncurrent	771	771
Fair Value	$ 765	753
3.750% notes due July 2025 [Member]
Debt Instrument [Line Items]
Interest Rate	3.75%
Par Value	$ 2,000	2,000
Unsecured Long-term Debt, Noncurrent	1,987	1,986
Fair Value	$ 2,122	2,070
3.100% notes due March 2026 [Member]
Debt Instrument [Line Items]
Interest Rate	3.10%
Par Value	$ 1,000	1,000
Unsecured Long-term Debt, Noncurrent	995	994
Fair Value	$ 1,012	986
3.450% notes due January 2027 [Member]
Debt Instrument [Line Items]
Interest Rate	3.45%
Par Value	$ 750	750
Unsecured Long-term Debt, Noncurrent	745	745
Fair Value	$ 776	762
3.375% notes due April 2027 [Member]
Debt Instrument [Line Items]
Interest Rate	3.75%
Par Value	$ 625	0
Unsecured Long-term Debt, Noncurrent	618	0
Fair Value	$ 643	0
4.625% notes due July 2035 [Member]
Debt Instrument [Line Items]
Interest Rate	4.625%
Par Value	$ 1,000	1,000
Unsecured Long-term Debt, Noncurrent	991	991
Fair Value	$ 1,146	1,090
5.800% notes due March 2036 [Member]
Debt Instrument [Line Items]
Interest Rate	5.80%
Par Value	$ 850	850
Unsecured Long-term Debt, Noncurrent	837	837
Fair Value	$ 1,071	1,034
6.500% notes due June 2037 [Member]
Debt Instrument [Line Items]
Interest Rate	6.50%
Par Value	$ 500	500
Unsecured Long-term Debt, Noncurrent	491	491
Fair Value	$ 683	643
6.625% notes due November 2037 [Member]
Debt Instrument [Line Items]
Interest Rate	6.625%
Par Value	$ 650	650
Unsecured Long-term Debt, Noncurrent	641	640
Fair Value	$ 903	850
6.875% notes due February 2038 [Member]
Debt Instrument [Line Items]
Interest Rate	6.875%
Par Value	$ 1,100	1,100
Unsecured Long-term Debt, Noncurrent	1,075	1,075
Fair Value	$ 1,561	1,497
5.700% notes due October 2040 [Member]
Debt Instrument [Line Items]
Interest Rate	5.70%
Par Value	$ 300	300
Unsecured Long-term Debt, Noncurrent	296	296
Fair Value	$ 383	366
5.950% notes due February 2041 [Member]
Debt Instrument [Line Items]
Interest Rate	5.95%
Par Value	$ 350	350
Unsecured Long-term Debt, Noncurrent	345	345
Fair Value	$ 460	437
4.625% notes due November 2041 [Member]
Debt Instrument [Line Items]
Interest Rate	4.625%
Par Value	$ 600	600
Unsecured Long-term Debt, Noncurrent	588	588
Fair Value	$ 673	634
4.375% notes due March 2042 [Member]
Debt Instrument [Line Items]
Interest Rate	4.375%
Par Value	$ 502	502
Unsecured Long-term Debt, Noncurrent	483	483
Fair Value	$ 543	509
3.950% notes due October 2042 [Member]
Debt Instrument [Line Items]
Interest Rate	3.95%
Par Value	$ 625	625
Unsecured Long-term Debt, Noncurrent	607	606
Fair Value	$ 641	609
4.250% notes due March 2043 [Member]
Debt Instrument [Line Items]
Interest Rate	4.25%
Par Value	$ 750	750
Unsecured Long-term Debt, Noncurrent	734	734
Fair Value	$ 801	765
4.750% notes due July 2045 [Member]
Debt Instrument [Line Items]
Interest Rate	4.75%
Par Value	$ 2,000	2,000
Unsecured Long-term Debt, Noncurrent	1,972	1,972
Fair Value	$ 2,310	2,203
4.200% notes due January 2047 [Member]
Debt Instrument [Line Items]
Interest Rate	4.20%
Par Value	$ 750	750
Unsecured Long-term Debt, Noncurrent	738	737
Fair Value	$ 799	759
4.250% notes due April 2047 [Member]
Debt Instrument [Line Items]
Interest Rate	4.25%
Par Value	$ 725	0
Unsecured Long-term Debt, Noncurrent	717	0
Fair Value	$ 777	$ 0

Commercial Paper and Long-Ter38

Commercial Paper and Long-Term Debt Subsequent Events (Details) - USD ($) $ in Millions	Oct. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Debt Instrument, Face Amount		$ 29,102	$ 33,022
Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 4,000
Floating rate notes due October 2020 [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Face Amount	$ 300
1.950% notes due October 2020 [Member] [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.95%
Debt Instrument, Face Amount	$ 900
2.375% notes due October 2022 [Member] [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.375%
Debt Instrument, Face Amount	$ 900
2.950% notes due October 2027 [Member] [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.95%
Debt Instrument, Face Amount	$ 950
3.750% notes due October 2047 [Member] [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.75%
Debt Instrument, Face Amount	$ 950

Shareholders' Equity (Details)

Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 19, 2017	Jun. 27, 2017	Mar. 10, 2017	Sep. 30, 2017	Sep. 30, 2016
Class of Stock [Line Items]
Common Stock, Dividends, Per Share, Cash Paid	$ 0.750	$ 0.750	$ 0.625
Payments of Ordinary Dividends, Common Stock	$ 726	$ 724	$ 596	$ 2,046	$ 1,666

Commitments and Contingencies40

Commitments and Contingencies (Details) - California Claims Processing Matter [Member] - USD ($) $ in Millions	Jun. 09, 2014	Jan. 25, 2008	Aug. 31, 2013	Sep. 30, 2017
Loss Contingency [Line Items]
Estimated Largest Penalty Ever Issued By CDI				$ 8
CDI aggregate penalty		$ 325
California Administrative Law Judge [Member] | Judicial Ruling [Member]
Loss Contingency [Line Items]
Loss Contingency, Damages Awarded, Value			$ 11.5
California Insurance Commissioner [Member] | Judicial Ruling [Member]
Loss Contingency [Line Items]
Loss Contingency, Damages Awarded, Value	$ 174

Segment Financial Information41

Segment Financial Information (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Statement [Line Items]
Number of Reportable Segments	4
Assets	$ 140,432	$ 122,810
OptumHealth [Member]
Statement [Line Items]
Assets	26,100	$ 18,700
Goodwill, Period Increase (Decrease)	$ 5,100

Segment Financial Information42

Segment Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement [Line Items]
Premiums, revenues - external customers	$ 39,552	$ 36,142	$ 118,075	$ 107,366
Products, revenues - external customers	6,665	6,696	19,209	19,699
Services, revenues - external customers	3,858	3,264	11,089	9,673
Total revenues	50,322	46,293	149,098	137,305
Investment and other income	247	191	725	567
Earnings from operations	4,088	3,580	11,232	9,743
Interest expense	(294)	(269)	(878)	(799)
Earnings before income taxes	3,794	3,311	10,354	8,944
Optum [Member]
Statement [Line Items]
Total revenues	22,885	21,119	66,793	61,426
Investment and other income	94	58	247	145
Earnings from operations	1,697	1,467	4,496	3,834
Interest expense	0	0	0	0
Earnings before income taxes	1,697	1,467	4,496	3,834
External Customers [Member]
Statement [Line Items]
Premiums, revenues - external customers	39,552	36,142	118,075	107,366
Products, revenues - external customers	6,665	6,696	19,209	19,699
Services, revenues - external customers	3,858	3,264	11,089	9,673
Total revenues	50,075	46,102	148,373	136,738
External Customers [Member] | Optum [Member]
Statement [Line Items]
Premiums, revenues - external customers	976	1,005	2,780	2,725
Products, revenues - external customers	6,665	6,696	19,209	19,698
Services, revenues - external customers	1,853	1,357	5,204	4,104
Total revenues	9,494	9,058	27,193	26,527
Intersegment [Member]
Statement [Line Items]
Total revenues	0	0	0	0
Intersegment [Member] | Optum [Member]
Statement [Line Items]
Total revenues	13,297	12,003	39,353	34,754
Operating Segments [Member] | UnitedHealthcare [Member]
Statement [Line Items]
Total revenues	40,734	37,177	121,658	110,633
Investment and other income	153	133	478	422
Earnings from operations	2,391	2,113	6,736	5,909
Interest expense	0	0	0	0
Earnings before income taxes	2,391	2,113	6,736	5,909
Operating Segments [Member] | OptumHealth [Member]
Statement [Line Items]
Total revenues	5,252	4,332	15,107	12,395
Investment and other income	88	55	231	139
Earnings from operations	513	404	1,267	1,008
Interest expense	0	0	0	0
Earnings before income taxes	513	404	1,267	1,008
Operating Segments [Member] | OptumInsight [Member]
Statement [Line Items]
Total revenues	2,004	1,825	5,840	5,254
Investment and other income	1	1	3	1
Earnings from operations	414	371	1,080	950
Interest expense	0	0	0	0
Earnings before income taxes	414	371	1,080	950
Operating Segments [Member] | OptumRx [Member]
Statement [Line Items]
Total revenues	15,953	15,237	46,740	44,583
Investment and other income	5	2	13	5
Earnings from operations	770	692	2,149	1,876
Interest expense	0	0	0	0
Earnings before income taxes	770	692	2,149	1,876
Operating Segments [Member] | External Customers [Member] | UnitedHealthcare [Member]
Statement [Line Items]
Premiums, revenues - external customers	38,576	35,137	115,295	104,641
Products, revenues - external customers	0	0	0	1
Services, revenues - external customers	2,005	1,907	5,885	5,569
Total revenues	40,581	37,044	121,180	110,211
Operating Segments [Member] | External Customers [Member] | OptumHealth [Member]
Statement [Line Items]
Premiums, revenues - external customers	976	1,005	2,780	2,725
Products, revenues - external customers	10	12	33	36
Services, revenues - external customers	1,040	604	2,769	1,813
Total revenues	2,026	1,621	5,582	4,574
Operating Segments [Member] | External Customers [Member] | OptumInsight [Member]
Statement [Line Items]
Premiums, revenues - external customers	0	0	0	0
Products, revenues - external customers	29	30	69	67
Services, revenues - external customers	677	617	2,011	1,862
Total revenues	706	647	2,080	1,929
Operating Segments [Member] | External Customers [Member] | OptumRx [Member]
Statement [Line Items]
Premiums, revenues - external customers	0	0	0	0
Products, revenues - external customers	6,626	6,654	19,107	19,595
Services, revenues - external customers	136	136	424	429
Total revenues	6,762	6,790	19,531	20,024
Operating Segments [Member] | Intersegment [Member] | UnitedHealthcare [Member]
Statement [Line Items]
Total revenues	0	0	0	0
Operating Segments [Member] | Intersegment [Member] | OptumHealth [Member]
Statement [Line Items]
Total revenues	3,138	2,656	9,294	7,682
Operating Segments [Member] | Intersegment [Member] | OptumInsight [Member]
Statement [Line Items]
Total revenues	1,297	1,177	3,757	3,324
Operating Segments [Member] | Intersegment [Member] | OptumRx [Member]
Statement [Line Items]
Total revenues	9,186	8,445	27,196	24,554
Optum Eliminations [Member]
Statement [Line Items]
Total revenues	(324)	(275)	(894)	(806)
Investment and other income	0	0	0	0
Earnings from operations	0	0	0	0
Interest expense	0	0	0	0
Earnings before income taxes	0	0	0	0
Optum Eliminations [Member] | External Customers [Member]
Statement [Line Items]
Premiums, revenues - external customers	0	0	0	0
Products, revenues - external customers	0	0	0	0
Services, revenues - external customers	0	0	0	0
Total revenues	0	0	0	0
Optum Eliminations [Member] | Intersegment [Member]
Statement [Line Items]
Total revenues	(324)	(275)	(894)	(806)
Corporate and Eliminations [Member]
Statement [Line Items]
Total revenues	(13,297)	(12,003)	(39,353)	(34,754)
Investment and other income	0	0	0	0
Earnings from operations	0	0	0	0
Interest expense	(294)	(269)	(878)	(799)
Earnings before income taxes	(294)	(269)	(878)	(799)
Corporate and Eliminations [Member] | External Customers [Member]
Statement [Line Items]
Premiums, revenues - external customers	0	0	0	0
Products, revenues - external customers	0	0	0	0
Services, revenues - external customers	0	0	0	0
Total revenues	0	0	0	0
Corporate and Eliminations [Member] | Intersegment [Member]
Statement [Line Items]
Total revenues	$ (13,297)	$ (12,003)	$ (39,353)	$ (34,754)