UnitedHealth (UNH) 10-Q 8 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
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 Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		962,034,200

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 10,263	$ 11,981
Short-term investments	3,586	3,509
Accounts receivable, net	10,992	9,568
Other current receivables, net	7,270	6,262
Assets under management	2,936	3,101
Prepaid expenses and other current assets	3,707	2,663
Total current assets	38,754	37,084
Long-term investments	31,929	28,341
Property, equipment and capitalized software, net	8,042	7,013
Goodwill	58,703	54,556
Other intangible assets, net	9,498	8,489
Other assets	4,161	3,575
Total assets	151,087	139,058
Current liabilities:
Medical costs payable	19,850	17,871
Accounts payable and accrued liabilities	18,991	15,180
Commercial paper and current maturities of long-term debt	1,500	2,857
Unearned revenues	2,388	2,269
Other current liabilities	13,648	12,286
Total current liabilities	56,377	50,463
Long-term debt, less current maturities	32,053	28,835
Deferred income taxes	2,434	2,182
Other liabilities	5,858	5,556
Total liabilities	96,722	87,036
Commitments and contingencies (Note 7)
Redeemable noncontrolling interests	1,769	2,189
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; 962 and 969 issued and outstanding	10	10
Additional paid-in capital	0	1,703
Retained earnings	54,386	48,730
Accumulated other comprehensive loss	(4,386)	(2,667)
Nonredeemable noncontrolling interests	2,586	2,057
Total equity	52,596	49,833
Total liabilities, redeemable noncontrolling interests and equity	$ 151,087	$ 139,058

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheet (Parenthetical) - $ / shares shares in Millions	Sep. 30, 2018	Dec. 31, 2017
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	3,000	3,000
Common stock, shares issued	962	969
Common stock, shares outstanding	962	969
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, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Premiums	$ 44,613	$ 39,552	$ 133,155	$ 118,075
Products	7,344	6,665	21,050	19,209
Services	4,217	3,858	12,590	11,089
Investment and other income	382	247	1,035	725
Total revenues	56,556	50,322	167,830	149,098
Operating costs:
Medical costs	36,158	32,201	108,448	96,829
Operating costs	8,479	7,387	25,371	21,737
Cost of products sold	6,718	6,068	19,373	17,633
Depreciation and amortization	611	578	1,791	1,667
Total operating costs	51,966	46,234	154,983	137,866
Earnings from operations	4,590	4,088	12,847	11,232
Interest expense	(353)	(294)	(1,026)	(878)
Earnings before income taxes	4,237	3,794	11,821	10,354
Provision for income taxes	(953)	(1,233)	(2,603)	(3,252)
Net earnings	3,284	2,561	9,218	7,102
Earnings attributable to noncontrolling interests	(96)	(76)	(272)	(161)
Net earnings attributable to UnitedHealth Group common shareholders	$ 3,188	$ 2,485	$ 8,946	$ 6,941
Earnings per share attributable to UnitedHealth Group common shareholders:
Basic	$ 3.31	$ 2.57	$ 9.29	$ 7.22
Diluted	$ 3.24	$ 2.51	$ 9.09	$ 7.06
Basic weighted-average number of common shares outstanding	962	968	963	962
Dilutive effect of common share equivalents	21	21	21	21
Diluted weighted-average number of common shares outstanding	983	989	984	983
Anti-dilutive shares excluded from the calculation of dilutive effect of common share equivalents	7	1	7	6

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Net earnings	$ 3,284	$ 2,561	$ 9,218	$ 7,102
Other comprehensive (loss) income:
Gross unrealized (losses) gains on investment securities during the period	(91)	44	(512)	313
Income tax effect	21	(17)	117	(111)
Total unrealized (losses) gains, net of tax	(70)	27	(395)	202
Gross reclassification adjustment for net realized gains included in net earnings	(3)	(10)	(58)	(51)
Income tax effect	0	4	13	19
Total reclassification adjustment, net of tax	(3)	(6)	(45)	(32)
Total foreign currency translation (losses) gains	(233)	217	(1,303)	158
Other comprehensive (loss) income	(306)	238	(1,743)	328
Comprehensive income	2,978	2,799	7,475	7,430
Comprehensive income attributable to noncontrolling interests	(96)	(76)	(272)	(161)
Comprehensive income attributable to UnitedHealth Group common shareholders	$ 2,882	$ 2,723	$ 7,203	$ 7,269

Condensed Consolidated Statem_3

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 (Losses) Gains on Investments [Member]	Foreign Currency Translation [Member]	Nonredeemable Noncontrolling Interests [Member]
Balance at Dec. 31, 2016	$ 38,177	$ 10	$ 0	$ 40,945	$ (97)	$ (2,584)	$ (97)
Balance (in shares) at Dec. 31, 2016		952
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 ($2.55 per share, and $2.125 per share for nine months ended September 30, 2018 and September 30, 2017, respectively)	(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 at Sep. 30, 2017	47,310	$ 10	1,801	45,840	73	(2,426)	2,012
Balance (in shares) at Sep. 30, 2017		969
Balance at Dec. 31, 2017	$ 49,833	$ 10	1,703	48,730	(13)	(2,654)	2,057
Balance (in shares) at Dec. 31, 2017	969	969
Adjustment to adopt ASU 2016-01 at Dec. 31, 2017	$ 0			(24)	24
Net earnings attributable to UnitedHealth Group common shareholders	8,946			8,946
Net earnings attributable to nonredeemable noncontrolling interest							183
Net Earnings, Including Portion Attributable to Nonredeemable Noncontrolling Interest	9,129
Other comprehensive income (loss)	(1,743)				(440)	(1,303)
Issuances of common stock, and related tax effects (in shares)		9
Issuances of common stock, and related tax effects	761	$ 0	761
Share-based compensation	$ 493		493
Common share repurchases (in shares)	(16)	(16)
Common share repurchases	$ (3,650)	$ 0	(2,838)	(812)
Cash dividends paid on common shares ($2.55 per share, and $2.125 per share for nine months ended September 30, 2018 and September 30, 2017, respectively)	(2,454)			(2,454)
Redeemable noncontrolling interests fair value and other adjustments	(119)		(119)
Acquisition of nonredeemable noncontrolling interests	518						518
Distribution to nonredeemable noncontrolling interest	(172)						(172)
Balance at Sep. 30, 2018	$ 52,596	$ 10	$ 0	$ 54,386	$ (429)	$ (3,957)	$ 2,586
Balance (in shares) at Sep. 30, 2018	962	962

Condensed Consolidated Statem_4

Condensed Consolidated Statement of Changes in Equity (Parenthetical) - $ / shares	Sep. 18, 2018	Jun. 26, 2018	Mar. 20, 2018	Sep. 30, 2018	Sep. 30, 2017
Statement of Stockholders' Equity [Abstract]
Common Stock, Dividends, Per Share, Cash Paid	$ 0.90	$ 0.90	$ 0.75	$ 2.55	$ 2.125

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating activities
Net earnings	$ 9,218	$ 7,102
Noncash items:
Depreciation and amortization	1,791	1,667
Deferred income taxes	9	(459)
Share-based compensation	512	456
Other, net	(136)	168
Net change in other operating items, net of effects from acquisitions and changes in AARP balances:
Accounts receivable	(984)	(244)
Other assets	(1,641)	(763)
Medical costs payable	1,745	1,305
Accounts payable and other liabilities	2,783	2,283
Unearned revenues	20	4,658
Cash flows from operating activities	13,317	16,173
Investing activities
Purchases of investments	(11,316)	(10,626)
Sales of investments	2,872	2,809
Maturities of investments	4,715	4,251
Cash paid for acquisitions, net of cash assumed	(5,824)	(908)
Purchases of property, equipment and capitalized software	(1,505)	(1,391)
Other, net	(187)	(30)
Cash flows used for investing activities	(11,245)	(5,895)
Financing activities
Common share repurchases	(3,650)	(1,173)
Cash dividends paid	(2,454)	(2,046)
Proceeds from common stock issuances	745	604
Repayments of long-term debt	(2,600)	(2,867)
Repayments of commercial paper, net	(164)	(3,352)
Proceeds from issuance of long-term debt	3,964	1,342
Customer funds administered	1,552	3,659
Other, net	(1,086)	(624)
Cash flows used for financing activities	(3,693)	(4,457)
Effect of exchange rate changes on cash and cash equivalents	(97)	18
(Decrease) increase in cash and cash equivalents	(1,718)	5,839
Cash and cash equivalents, beginning of period	11,981	10,430
Cash and cash equivalents, end of period	10,263	16,269
Supplemental schedule of noncash investing activities
Common stock issued for acquisition	$ 0	$ 2,164

Basis of Presentation (Notes)

Basis of Presentation (Notes)	9 Months Ended
	Sep. 30, 2018
Basis of Presentation and Significant Accounting Policies [Text Block]	Basis of Presentation UnitedHealth Group Incorporated (individually and together with its subsidiaries, “UnitedHealth Group” and the “Company”) is a diversified health care 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 data and health information; advanced technology; and clinical expertise to help meet the demands of the health system. These core competencies are deployed within 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, 2017 as filed with the SEC ( 2017 10-K). The accompanying Condensed Consolidated Financial Statements include all normal recurring adjustments necessary to present the interim financial statements fairly. Use of Estimates These Condensed Consolidated Financial Statements include certain amounts based on the Company’s best estimates and judgments. The Company’s most significant estimates relate to medical costs payable, revenues, and goodwill and other intangible assets. 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. Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) No. 2016-02, “Leases (Topic 842)”, as modified by ASUs 2018-01, 2018-10 and 2018-11 (collectively, 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 may adopt the new standard using a modified retrospective approach or a cumulative effect upon adoption approach for the annual and interim periods beginning after December 15, 2018. Early adoption of ASU 2016-02 is permitted. When adopted, ASU 2016-02 will not have a material impact on the Company’s balance sheet, results of operations, equity or cash flows. Recently Adopted Accounting Standards 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). Most notably, the new guidance 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 Company adopted ASU 2016-01 on a prospective basis effective January 1, 2018, as required, and reclassified $24 million from accumulated other comprehensive income to retained earnings. 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, 2018
Investments [Abstract]
Investments [Text Block]	Investments A summary of debt securities by major security type is as follows: (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value September 30, 2018 Debt securities - available-for-sale: U.S. government and agency obligations $ 3,291 $ — $ (76 ) $ 3,215 State and municipal obligations 6,962 30 (112 ) 6,880 Corporate obligations 15,561 10 (208 ) 15,363 U.S. agency mortgage-backed securities 4,846 1 (171 ) 4,676 Non-U.S. agency mortgage-backed securities 1,329 — (30 ) 1,299 Total debt securities - available-for-sale 31,989 41 (597 ) 31,433 Debt securities - held-to-maturity: U.S. government and agency obligations 246 1 (3 ) 244 State and municipal obligations 11 — — 11 Corporate obligations 342 — — 342 Total debt securities - held-to-maturity 599 1 (3 ) 597 Total debt securities $ 32,588 $ 42 $ (600 ) $ 32,030 December 31, 2017 Debt securities - available-for-sale: U.S. government and agency obligations $ 2,673 $ 1 $ (30 ) $ 2,644 State and municipal obligations 7,596 99 (35 ) 7,660 Corporate obligations 13,181 57 (44 ) 13,194 U.S. agency mortgage-backed securities 3,942 7 (38 ) 3,911 Non-U.S. agency mortgage-backed securities 1,018 3 (6 ) 1,015 Total debt securities - available-for-sale 28,410 167 (153 ) 28,424 Debt securities - held-to-maturity: U.S. government and agency obligations 254 1 (1 ) 254 State and municipal obligations 2 — — 2 Corporate obligations 280 — — 280 Total debt securities - held-to-maturity 536 1 (1 ) 536 Total debt securities $ 28,946 $ 168 $ (154 ) $ 28,960 The Company held $2.0 billion of equity securities as of September 30, 2018 and December 31, 2017. The Company’s investments in equity securities primarily consist of investments in Brazilian real denominated fixed-income funds, employee savings plan related investments and dividend paying stocks, with readily determinable fair values. Additionally, the Company’s investments included $ 1.5 billion and $0.9 billion of equity method investments in operating businesses in the health care sector as of September 30, 2018 and December 31, 2017, respectively. The amortized cost and fair value of debt securities as of September 30, 2018 , 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 $ 3,683 $ 3,675 $ 145 $ 145 Due after one year through five years 12,362 12,197 180 178 Due after five years through ten years 7,194 7,041 102 101 Due after ten years 2,575 2,545 172 173 U.S. agency mortgage-backed securities 4,846 4,676 — — Non-U.S. agency mortgage-backed securities 1,329 1,299 — — Total debt securities $ 31,989 $ 31,433 $ 599 $ 597 The fair value of available-for-sale debt securities with gross unrealized losses by 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, 2018 Debt securities - available-for-sale: U.S. government and agency obligations $ 2,025 $ (33 ) $ 1,068 $ (43 ) $ 3,093 $ (76 ) State and municipal obligations 3,471 (54 ) 1,596 (58 ) 5,067 (112 ) Corporate obligations 9,933 (136 ) 2,334 (72 ) 12,267 (208 ) U.S. agency mortgage-backed securities 2,762 (74 ) 1,811 (97 ) 4,573 (171 ) Non-U.S. agency mortgage-backed securities 956 (19 ) 265 (11 ) 1,221 (30 ) Total debt securities - available-for-sale $ 19,147 $ (316 ) $ 7,074 $ (281 ) $ 26,221 $ (597 ) December 31, 2017 Debt securities - available-for-sale: U.S. government and agency obligations $ 1,249 $ (8 ) $ 1,027 $ (22 ) $ 2,276 $ (30 ) State and municipal obligations 2,599 (21 ) 866 (14 ) 3,465 (35 ) Corporate obligations 5,901 (23 ) 1,242 (21 ) 7,143 (44 ) U.S. agency mortgage-backed securities 1,657 (12 ) 1,162 (26 ) 2,819 (38 ) Non-U.S. agency mortgage-backed securities 411 (3 ) 144 (3 ) 555 (6 ) Total debt securities - available-for-sale $ 11,817 $ (67 ) $ 4,441 $ (86 ) $ 16,258 $ (153 ) The Company’s unrealized losses from debt securities as of September 30, 2018 were generated from 20,000 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, 2018 , 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.

Fair Value (Notes)

Fair Value (Notes)	9 Months Ended
	Sep. 30, 2018
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 2017 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, 2018 Cash and cash equivalents $ 10,220 $ 43 $ — $ 10,263 Debt securities - available-for-sale: U.S. government and agency obligations 2,928 287 — 3,215 State and municipal obligations — 6,880 — 6,880 Corporate obligations 41 15,163 159 15,363 U.S. agency mortgage-backed securities — 4,676 — 4,676 Non-U.S. agency mortgage-backed securities — 1,299 — 1,299 Total debt securities - available-for-sale 2,969 28,305 159 31,433 Equity securities 1,885 13 100 1,998 Assets under management 993 1,939 4 2,936 Total assets at fair value $ 16,067 $ 30,300 $ 263 $ 46,630 Percentage of total assets at fair value 34 % 65 % 1 % 100 % December 31, 2017 Cash and cash equivalents $ 11,718 $ 263 $ — $ 11,981 Debt securities - available-for-sale: U.S. government and agency obligations 2,428 216 — 2,644 State and municipal obligations — 7,660 — 7,660 Corporate obligations 65 12,989 140 13,194 U.S. agency mortgage-backed securities — 3,911 — 3,911 Non-U.S. agency mortgage-backed securities — 1,015 — 1,015 Total debt securities - available-for-sale 2,493 25,791 140 28,424 Equity securities 1,784 14 194 1,992 Assets under management 1,117 1,984 — 3,101 Total assets at fair value $ 17,112 $ 28,052 $ 334 $ 45,498 Percentage of total assets at fair value 38 % 61 % 1 % 100 % 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 during the nine months ended September 30, 2018 or 2017 . 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, 2018 Debt securities - held-to-maturity $ 257 $ 71 $ 269 $ 597 $ 599 Long-term debt and other financing obligations $ — $ 34,908 $ — $ 34,908 $ 33,533 December 31, 2017 Debt securities - held-to-maturity $ 267 $ 4 $ 265 $ 536 $ 536 Long-term debt and other financing obligations $ — $ 34,504 $ — $ 34,504 $ 31,542 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, 2018 or 2017 .

Medical Costs Payable (Notes)

Medical Costs Payable (Notes)	9 Months Ended
	Sep. 30, 2018
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) 2018 2017 Medical costs payable, beginning of period $ 17,871 $ 16,391 Acquisitions 333 76 Reported medical costs: Current year 108,658 97,519 Prior years (210 ) (690 ) Total reported medical costs 108,448 96,829 Medical payments: Payments for current year (90,348 ) (81,237 ) Payments for prior years (16,454 ) (14,096 ) Total medical payments (106,802 ) (95,333 ) Medical costs payable, end of period $ 19,850 $ 17,963 For the nine months ended September 30, 2018 , the medical cost reserve development included no individual factors that were significant. For the nine months ended September 30, 2017, the medical cost reserve development was primarily driven by lower than expected health system utilization levels. Medical costs payable included reserves for claims incurred by insured customers but not yet reported to the Company of $13.8 billion and $12.3 billion at September 30, 2018 and December 31, 2017, respectively.

Commercial Paper and Long-Term

Commercial Paper and Long-Term Debt (Notes)	9 Months Ended
	Sep. 30, 2018
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, 2018 December 31, 2017 (in millions, except percentages) Par Carrying Fair Par Carrying Fair Commercial paper $ 20 $ 20 $ 20 $ 150 $ 150 $ 150 6.000% notes due February 2018 — — — 1,100 1,101 1,106 1.900% notes due July 2018 — — — 1,500 1,499 1,501 1.700% notes due February 2019 750 750 747 750 749 747 1.625% notes due March 2019 500 500 498 500 501 497 2.300% notes due December 2019 500 492 496 500 495 501 2.700% notes due July 2020 1,500 1,497 1,491 1,500 1,496 1,517 Floating rate notes due October 2020 300 299 300 300 299 300 3.875% notes due October 2020 450 439 456 450 446 467 1.950% notes due October 2020 900 897 881 900 895 892 4.700% notes due February 2021 400 395 412 400 403 425 2.125% notes due March 2021 750 747 732 750 746 744 Floating rate notes due June 2021 350 349 350 — — — 3.150% notes due June 2021 400 398 399 — — — 3.375% notes due November 2021 500 481 502 500 493 516 2.875% notes due December 2021 750 724 741 750 741 760 2.875% notes due March 2022 1,100 1,031 1,083 1,100 1,054 1,114 3.350% notes due July 2022 1,000 997 999 1,000 996 1,033 2.375% notes due October 2022 900 894 863 900 893 891 0.000% notes due November 2022 15 12 12 15 12 12 2.750% notes due February 2023 625 588 606 625 606 626 2.875% notes due March 2023 750 734 731 750 762 759 3.500% notes due June 2023 750 746 752 — — — 3.750% notes due July 2025 2,000 1,989 2,010 2,000 1,987 2,108 3.100% notes due March 2026 1,000 995 961 1,000 995 1,007 3.450% notes due January 2027 750 745 734 750 745 776 3.375% notes due April 2027 625 619 607 625 618 642 2.950% notes due October 2027 950 938 890 950 937 947 3.850% notes due June 2028 1,150 1,142 1,153 — — — 4.625% notes due July 2035 1,000 991 1,064 1,000 991 1,165 5.800% notes due March 2036 850 838 1,013 850 837 1,105 6.500% notes due June 2037 500 492 640 500 491 698 6.625% notes due November 2037 650 641 844 650 641 923 6.875% notes due February 2038 1,100 1,076 1,467 1,100 1,075 1,596 5.700% notes due October 2040 300 296 358 300 296 389 5.950% notes due February 2041 350 345 428 350 345 466 4.625% notes due November 2041 600 588 630 600 588 685 4.375% notes due March 2042 502 484 510 502 483 555 3.950% notes due October 2042 625 607 596 625 607 650 4.250% notes due March 2043 750 734 749 750 734 822 4.750% notes due July 2045 2,000 1,972 2,140 2,000 1,972 2,362 4.200% notes due January 2047 750 738 743 750 738 808 4.250% notes due April 2047 725 717 728 725 717 798 3.750% notes due October 2047 950 933 883 950 933 969 4.250% notes due June 2048 1,350 1,329 1,355 — — — Total commercial paper and long-term debt $ 32,687 $ 32,199 $ 33,574 $ 31,417 $ 31,067 $ 34,029 The Company’s long-term debt obligations included $ 1.4 billion and $625 million of other financing obligations, of which $230 million and $107 million were classified as current as of September 30, 2018 and December 31, 2017 , respectively. 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, 2018 , the Company’s outstanding commercial paper had a weighted average annual interest rate of 2.1% . The Company has $3.0 billion five-year, $3.0 billion three-year and $4.0 billion 364-day revolving bank credit facilities with 26 banks, which mature in December 2022 , December 2020 and December 2018, respectively. These facilities provide liquidity support for the Company’s commercial paper program and are available for general corporate purposes. As of September 30, 2018 , 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, 2018 , annual interest rates would have ranged from 3.1% to 3.4% . 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, 2018 .

Shareholders' Equity (Notes)

Shareholders' Equity (Notes)	9 Months Ended
	Sep. 30, 2018
Shareholders' Equity [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	Shareholders' Equity Share Repurchase Program In June 2018, the Company’s Board of Directors renewed the Company’s share repurchase program with an authorization to repurchase up to 100 million shares of the Company’s common stock. The following table provides details of the Company’s share repurchase activity for the nine months ended September 30, 2018 : (in millions, except per share data) Common share repurchases, shares 16 Common share repurchases, average price per share $ 232.61 Common share repurchases, aggregate cost $ 3,650 Board authorized shares remaining 98 Dividends In June 2018, the Company’s Board of Directors increased the Company’s quarterly cash dividend to shareholders to an annual dividend rate of $ 3.60 per share from $ 3.00 per share, which the Company had paid since June 2017. 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 2018 dividend payments: Payment Date Amount per Share Total Amount Paid (in millions) March 20 $ 0.75 $ 722 June 26 0.90 866 September 18 0.90 866

Commitments and Contingencies (

Commitments and Contingencies (Notes)	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies Legal Matters Because of the nature of its businesses, the Company is frequently made party to a variety of legal actions and regulatory inquiries, including class actions and suits brought by members, care providers, consumer advocacy organizations, customers and regulators, relating to the Company’s businesses, including management and administration of health benefit plans and other services. These matters include medical malpractice, employment, intellectual property, antitrust, privacy and contract claims and claims related to health care benefits coverage and other business practices. The Company records liabilities for its estimates of probable costs resulting from these matters where appropriate. Estimates of costs resulting from legal and regulatory matters involving the Company are inherently difficult to predict, particularly where the matters: involve indeterminate claims for monetary damages or may involve fines, penalties or punitive damages; present novel legal theories or represent a shift in regulatory policy; involve a large number of claimants or regulatory bodies; are in the early stages of the proceedings; or could result in a change in business practices. Accordingly, the Company is often unable to estimate the losses or ranges of losses for those matters where there is a reasonable possibility or it is probable that a loss may be incurred. 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 Centers for Medicare and Medicaid Services (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 made improper risk adjustment submissions and violated the False Claims Act. On February 12, 2018, the court granted in part and denied in part the Company’s motion to dismiss. In May 2018, DOJ moved to dismiss the Company’s counterclaims, which were filed in March 2018, and moved for partial summary judgment. Those motions were argued in September 2018. The Company cannot reasonably estimate the outcome that may result from this matter given its procedural status.

Segment Financial Information (

Segment Financial Information (Notes)	9 Months Ended
	Sep. 30, 2018
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 2017 10-K. 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, 2018 Revenues - unaffiliated customers: Premiums $ 43,628 $ 985 $ — $ — $ — $ 985 $ — $ 44,613 Products — 13 29 7,302 — 7,344 — 7,344 Services 2,067 1,196 790 164 — 2,150 — 4,217 Total revenues - unaffiliated customers 45,695 2,194 819 7,466 — 10,479 — 56,174 Total revenues - affiliated customers — 3,733 1,431 9,960 (352 ) 14,772 (14,772 ) — Investment and other income 242 125 4 11 — 140 — 382 Total revenues $ 45,937 $ 6,052 $ 2,254 $ 17,437 $ (352 ) $ 25,391 $ (14,772 ) $ 56,556 Earnings from operations $ 2,559 $ 622 $ 534 $ 875 $ — $ 2,031 $ — $ 4,590 Interest expense — — — — — — (353 ) (353 ) Earnings before income taxes $ 2,559 $ 622 $ 534 $ 875 $ — $ 2,031 $ (353 ) $ 4,237 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 Optum (in millions) UnitedHealthcare OptumHealth OptumInsight OptumRx Optum Eliminations Optum Corporate and Eliminations Consolidated Nine Months Ended September 30, 2018 Revenues - unaffiliated customers: Premiums $ 130,361 $ 2,794 $ — $ — $ — $ 2,794 $ — $ 133,155 Products — 37 72 20,941 — 21,050 — 21,050 Services 6,248 3,587 2,306 449 — 6,342 — 12,590 Total revenues - unaffiliated customers 136,609 6,418 2,378 21,390 — 30,186 — 166,795 Total revenues - affiliated customers — 10,979 4,115 29,062 (1,026 ) 43,130 (43,130 ) — Investment and other income 633 355 15 32 — 402 — 1,035 Total revenues $ 137,242 $ 17,752 $ 6,508 $ 50,484 $ (1,026 ) $ 73,718 $ (43,130 ) $ 167,830 Earnings from operations $ 7,316 $ 1,680 $ 1,382 $ 2,469 $ — $ 5,531 $ — $ 12,847 Interest expense — — — — — — (1,026 ) (1,026 ) Earnings before income taxes $ 7,316 $ 1,680 $ 1,382 $ 2,469 $ — $ 5,531 $ (1,026 ) $ 11,821 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

Basis of Presentation Basis of

Basis of Presentation Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2018
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, 2017 as filed with the SEC ( 2017 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 medical costs payable, revenues, and goodwill and other intangible assets. 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.
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)”, as modified by ASUs 2018-01, 2018-10 and 2018-11 (collectively, 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 may adopt the new standard using a modified retrospective approach or a cumulative effect upon adoption approach for the annual and interim periods beginning after December 15, 2018. Early adoption of ASU 2016-02 is permitted. When adopted, ASU 2016-02 will not have a material impact on the Company’s balance sheet, results of operations, equity or cash flows. Recently Adopted Accounting Standards 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). Most notably, the new guidance 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 Company adopted ASU 2016-01 on a prospective basis effective January 1, 2018, as required, and reclassified $24 million from accumulated other comprehensive income to retained earnings. 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, 2018
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, 2018 , 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, 2018
Short-Term and Long-Term Investments [Table Text Block]	A summary of debt securities by major security type is as follows: (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value September 30, 2018 Debt securities - available-for-sale: U.S. government and agency obligations $ 3,291 $ — $ (76 ) $ 3,215 State and municipal obligations 6,962 30 (112 ) 6,880 Corporate obligations 15,561 10 (208 ) 15,363 U.S. agency mortgage-backed securities 4,846 1 (171 ) 4,676 Non-U.S. agency mortgage-backed securities 1,329 — (30 ) 1,299 Total debt securities - available-for-sale 31,989 41 (597 ) 31,433 Debt securities - held-to-maturity: U.S. government and agency obligations 246 1 (3 ) 244 State and municipal obligations 11 — — 11 Corporate obligations 342 — — 342 Total debt securities - held-to-maturity 599 1 (3 ) 597 Total debt securities $ 32,588 $ 42 $ (600 ) $ 32,030 December 31, 2017 Debt securities - available-for-sale: U.S. government and agency obligations $ 2,673 $ 1 $ (30 ) $ 2,644 State and municipal obligations 7,596 99 (35 ) 7,660 Corporate obligations 13,181 57 (44 ) 13,194 U.S. agency mortgage-backed securities 3,942 7 (38 ) 3,911 Non-U.S. agency mortgage-backed securities 1,018 3 (6 ) 1,015 Total debt securities - available-for-sale 28,410 167 (153 ) 28,424 Debt securities - held-to-maturity: U.S. government and agency obligations 254 1 (1 ) 254 State and municipal obligations 2 — — 2 Corporate obligations 280 — — 280 Total debt securities - held-to-maturity 536 1 (1 ) 536 Total debt securities $ 28,946 $ 168 $ (154 ) $ 28,960
Investments by Contractual Maturity [Table Text Block]	The amortized cost and fair value of debt securities as of September 30, 2018 , 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 $ 3,683 $ 3,675 $ 145 $ 145 Due after one year through five years 12,362 12,197 180 178 Due after five years through ten years 7,194 7,041 102 101 Due after ten years 2,575 2,545 172 173 U.S. agency mortgage-backed securities 4,846 4,676 — — Non-U.S. agency mortgage-backed securities 1,329 1,299 — — Total debt securities $ 31,989 $ 31,433 $ 599 $ 597
Fair Value of Available-for-Sale Investments with Gross Unrealized Losses by Investment Type and Length of Time that Individual Securities have been in a Continuous Unrealized Loss Position [Table Text Block]	The fair value of available-for-sale debt securities with gross unrealized losses by 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, 2018 Debt securities - available-for-sale: U.S. government and agency obligations $ 2,025 $ (33 ) $ 1,068 $ (43 ) $ 3,093 $ (76 ) State and municipal obligations 3,471 (54 ) 1,596 (58 ) 5,067 (112 ) Corporate obligations 9,933 (136 ) 2,334 (72 ) 12,267 (208 ) U.S. agency mortgage-backed securities 2,762 (74 ) 1,811 (97 ) 4,573 (171 ) Non-U.S. agency mortgage-backed securities 956 (19 ) 265 (11 ) 1,221 (30 ) Total debt securities - available-for-sale $ 19,147 $ (316 ) $ 7,074 $ (281 ) $ 26,221 $ (597 ) December 31, 2017 Debt securities - available-for-sale: U.S. government and agency obligations $ 1,249 $ (8 ) $ 1,027 $ (22 ) $ 2,276 $ (30 ) State and municipal obligations 2,599 (21 ) 866 (14 ) 3,465 (35 ) Corporate obligations 5,901 (23 ) 1,242 (21 ) 7,143 (44 ) U.S. agency mortgage-backed securities 1,657 (12 ) 1,162 (26 ) 2,819 (38 ) Non-U.S. agency mortgage-backed securities 411 (3 ) 144 (3 ) 555 (6 ) Total debt securities - available-for-sale $ 11,817 $ (67 ) $ 4,441 $ (86 ) $ 16,258 $ (153 )

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2018
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, 2018 Cash and cash equivalents $ 10,220 $ 43 $ — $ 10,263 Debt securities - available-for-sale: U.S. government and agency obligations 2,928 287 — 3,215 State and municipal obligations — 6,880 — 6,880 Corporate obligations 41 15,163 159 15,363 U.S. agency mortgage-backed securities — 4,676 — 4,676 Non-U.S. agency mortgage-backed securities — 1,299 — 1,299 Total debt securities - available-for-sale 2,969 28,305 159 31,433 Equity securities 1,885 13 100 1,998 Assets under management 993 1,939 4 2,936 Total assets at fair value $ 16,067 $ 30,300 $ 263 $ 46,630 Percentage of total assets at fair value 34 % 65 % 1 % 100 % December 31, 2017 Cash and cash equivalents $ 11,718 $ 263 $ — $ 11,981 Debt securities - available-for-sale: U.S. government and agency obligations 2,428 216 — 2,644 State and municipal obligations — 7,660 — 7,660 Corporate obligations 65 12,989 140 13,194 U.S. agency mortgage-backed securities — 3,911 — 3,911 Non-U.S. agency mortgage-backed securities — 1,015 — 1,015 Total debt securities - available-for-sale 2,493 25,791 140 28,424 Equity securities 1,784 14 194 1,992 Assets under management 1,117 1,984 — 3,101 Total assets at fair value $ 17,112 $ 28,052 $ 334 $ 45,498 Percentage of total assets at fair value 38 % 61 % 1 % 100 %
Fair Value Measurements, Nonrecurring [Table Text Block]	The following table presents a summary of fair value measurements by level and carrying values for certain financial instruments not measured at fair value on a recurring basis in the 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, 2018 Debt securities - held-to-maturity $ 257 $ 71 $ 269 $ 597 $ 599 Long-term debt and other financing obligations $ — $ 34,908 $ — $ 34,908 $ 33,533 December 31, 2017 Debt securities - held-to-maturity $ 267 $ 4 $ 265 $ 536 $ 536 Long-term debt and other financing obligations $ — $ 34,504 $ — $ 34,504 $ 31,542

Medical Costs Payable (Tables)

Medical Costs Payable (Tables)	9 Months Ended
	Sep. 30, 2018
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) 2018 2017 Medical costs payable, beginning of period $ 17,871 $ 16,391 Acquisitions 333 76 Reported medical costs: Current year 108,658 97,519 Prior years (210 ) (690 ) Total reported medical costs 108,448 96,829 Medical payments: Payments for current year (90,348 ) (81,237 ) Payments for prior years (16,454 ) (14,096 ) Total medical payments (106,802 ) (95,333 ) Medical costs payable, end of period $ 19,850 $ 17,963

Commercial Paper and Long-Ter_2

Commercial Paper and Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2018
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, 2018 December 31, 2017 (in millions, except percentages) Par Carrying Fair Par Carrying Fair Commercial paper $ 20 $ 20 $ 20 $ 150 $ 150 $ 150 6.000% notes due February 2018 — — — 1,100 1,101 1,106 1.900% notes due July 2018 — — — 1,500 1,499 1,501 1.700% notes due February 2019 750 750 747 750 749 747 1.625% notes due March 2019 500 500 498 500 501 497 2.300% notes due December 2019 500 492 496 500 495 501 2.700% notes due July 2020 1,500 1,497 1,491 1,500 1,496 1,517 Floating rate notes due October 2020 300 299 300 300 299 300 3.875% notes due October 2020 450 439 456 450 446 467 1.950% notes due October 2020 900 897 881 900 895 892 4.700% notes due February 2021 400 395 412 400 403 425 2.125% notes due March 2021 750 747 732 750 746 744 Floating rate notes due June 2021 350 349 350 — — — 3.150% notes due June 2021 400 398 399 — — — 3.375% notes due November 2021 500 481 502 500 493 516 2.875% notes due December 2021 750 724 741 750 741 760 2.875% notes due March 2022 1,100 1,031 1,083 1,100 1,054 1,114 3.350% notes due July 2022 1,000 997 999 1,000 996 1,033 2.375% notes due October 2022 900 894 863 900 893 891 0.000% notes due November 2022 15 12 12 15 12 12 2.750% notes due February 2023 625 588 606 625 606 626 2.875% notes due March 2023 750 734 731 750 762 759 3.500% notes due June 2023 750 746 752 — — — 3.750% notes due July 2025 2,000 1,989 2,010 2,000 1,987 2,108 3.100% notes due March 2026 1,000 995 961 1,000 995 1,007 3.450% notes due January 2027 750 745 734 750 745 776 3.375% notes due April 2027 625 619 607 625 618 642 2.950% notes due October 2027 950 938 890 950 937 947 3.850% notes due June 2028 1,150 1,142 1,153 — — — 4.625% notes due July 2035 1,000 991 1,064 1,000 991 1,165 5.800% notes due March 2036 850 838 1,013 850 837 1,105 6.500% notes due June 2037 500 492 640 500 491 698 6.625% notes due November 2037 650 641 844 650 641 923 6.875% notes due February 2038 1,100 1,076 1,467 1,100 1,075 1,596 5.700% notes due October 2040 300 296 358 300 296 389 5.950% notes due February 2041 350 345 428 350 345 466 4.625% notes due November 2041 600 588 630 600 588 685 4.375% notes due March 2042 502 484 510 502 483 555 3.950% notes due October 2042 625 607 596 625 607 650 4.250% notes due March 2043 750 734 749 750 734 822 4.750% notes due July 2045 2,000 1,972 2,140 2,000 1,972 2,362 4.200% notes due January 2047 750 738 743 750 738 808 4.250% notes due April 2047 725 717 728 725 717 798 3.750% notes due October 2047 950 933 883 950 933 969 4.250% notes due June 2048 1,350 1,329 1,355 — — — Total commercial paper and long-term debt $ 32,687 $ 32,199 $ 33,574 $ 31,417 $ 31,067 $ 34,029

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Equity, Class of Treasury Stock [Line Items]
Share Repurchase Activity	The following table provides details of the Company’s share repurchase activity for the nine months ended September 30, 2018 : (in millions, except per share data) Common share repurchases, shares 16 Common share repurchases, average price per share $ 232.61 Common share repurchases, aggregate cost $ 3,650 Board authorized shares remaining 98
Dividends Declared [Table Text Block]	The following table provides details of the Company’s 2018 dividend payments: Payment Date Amount per Share Total Amount Paid (in millions) March 20 $ 0.75 $ 722 June 26 0.90 866 September 18 0.90 866

Segment Financial Information_2

Segment Financial Information (Tables)	9 Months Ended
	Sep. 30, 2018
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, 2018 Revenues - unaffiliated customers: Premiums $ 43,628 $ 985 $ — $ — $ — $ 985 $ — $ 44,613 Products — 13 29 7,302 — 7,344 — 7,344 Services 2,067 1,196 790 164 — 2,150 — 4,217 Total revenues - unaffiliated customers 45,695 2,194 819 7,466 — 10,479 — 56,174 Total revenues - affiliated customers — 3,733 1,431 9,960 (352 ) 14,772 (14,772 ) — Investment and other income 242 125 4 11 — 140 — 382 Total revenues $ 45,937 $ 6,052 $ 2,254 $ 17,437 $ (352 ) $ 25,391 $ (14,772 ) $ 56,556 Earnings from operations $ 2,559 $ 622 $ 534 $ 875 $ — $ 2,031 $ — $ 4,590 Interest expense — — — — — — (353 ) (353 ) Earnings before income taxes $ 2,559 $ 622 $ 534 $ 875 $ — $ 2,031 $ (353 ) $ 4,237 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 Optum (in millions) UnitedHealthcare OptumHealth OptumInsight OptumRx Optum Eliminations Optum Corporate and Eliminations Consolidated Nine Months Ended September 30, 2018 Revenues - unaffiliated customers: Premiums $ 130,361 $ 2,794 $ — $ — $ — $ 2,794 $ — $ 133,155 Products — 37 72 20,941 — 21,050 — 21,050 Services 6,248 3,587 2,306 449 — 6,342 — 12,590 Total revenues - unaffiliated customers 136,609 6,418 2,378 21,390 — 30,186 — 166,795 Total revenues - affiliated customers — 10,979 4,115 29,062 (1,026 ) 43,130 (43,130 ) — Investment and other income 633 355 15 32 — 402 — 1,035 Total revenues $ 137,242 $ 17,752 $ 6,508 $ 50,484 $ (1,026 ) $ 73,718 $ (43,130 ) $ 167,830 Earnings from operations $ 7,316 $ 1,680 $ 1,382 $ 2,469 $ — $ 5,531 $ — $ 12,847 Interest expense — — — — — — (1,026 ) (1,026 ) Earnings before income taxes $ 7,316 $ 1,680 $ 1,382 $ 2,469 $ — $ 5,531 $ (1,026 ) $ 11,821 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

Basis of Presentation Basis o_2

Basis of Presentation Basis of Presentation, Uses of Estimates and Significant Accounting Policies (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ 24	$ 0
Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncement or Change in Accounting Principle, Description of Transition Method	Prospective
New Accounting Pronouncement, Transition Guidance Not Significant or Not Practical	Impact is not material
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncement or Change in Accounting Principle, Description of Transition Method	Modified retrospective or cumulative effect upon adoption approach
New Accounting Pronouncement, Transition Guidance Not Significant or Not Practical	Impact is not material

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Millions	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Investment [Line Items]
Equity Securities	$ 1,998	$ 1,992
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions	20,000
Total number of security positions	29,000
Equity Method Investments	$ 1,500	$ 900

Investments (Short-Term and Lon

Investments (Short-Term and Long-Term Investments) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	$ 31,989	$ 28,410
Securities, Available for sale Debt Securities, Gross Unrealized Gains	41	167
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(597)	(153)
Debt Securities, Available-for-sale	31,433	28,424
Held-to-maturity securities, Amortized Cost	599	536
Securities, Held to maturity, Unrecognized Holding Gain	1	1
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(3)	(1)
Debt Securities, Held-to-maturity, Fair Value	597	536
Total debt securities, Amortized Cost	32,588	28,946
Total debt securities, Gross Unrealized Gains	42	168
Total debt securities, Gross Unrealized Losses	(600)	(154)
Debt securities, Fair Value Disclosure	32,030	28,960
Debt Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale	31,433	28,424
U.S. Government and Agency Obligations [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	3,291	2,673
Securities, Available for sale Debt Securities, Gross Unrealized Gains	0	1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(76)	(30)
Debt Securities, Available-for-sale	3,215	2,644
Held-to-maturity securities, Amortized Cost	246	254
Securities, Held to maturity, Unrecognized Holding Gain	1	1
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(3)	(1)
Debt Securities, Held-to-maturity, Fair Value	244	254
State and Municipal Obligations [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	6,962	7,596
Securities, Available for sale Debt Securities, Gross Unrealized Gains	30	99
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(112)	(35)
Debt Securities, Available-for-sale	6,880	7,660
Held-to-maturity securities, Amortized Cost	11	2
Securities, Held to maturity, Unrecognized Holding Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Debt Securities, Held-to-maturity, Fair Value	11	2
Corporate Obligations [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	15,561	13,181
Securities, Available for sale Debt Securities, Gross Unrealized Gains	10	57
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(208)	(44)
Debt Securities, Available-for-sale	15,363	13,194
Held-to-maturity securities, Amortized Cost	342	280
Securities, Held to maturity, Unrecognized Holding Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Debt Securities, Held-to-maturity, Fair Value	342	280
U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	4,846	3,942
Securities, Available for sale Debt Securities, Gross Unrealized Gains	1	7
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(171)	(38)
Debt Securities, Available-for-sale	4,676	3,911
Non-U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	1,329	1,018
Securities, Available for sale Debt Securities, Gross Unrealized Gains	0	3
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(30)	(6)
Debt Securities, Available-for-sale	$ 1,299	$ 1,015

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, 2018	Dec. 31, 2017
Schedule of Investments [Line Items]
Due in one year or less, Amortized Cost	$ 3,683
Due after one year through five years, Amortized Cost	12,362
Due after five years through ten years, Amortized Cost	7,194
Due after ten years, Amortized Cost	2,575
Total debt securities - available-for-sale, Amortized Cost	31,989	$ 28,410
Due in one year or less, Fair Value	3,675
Due after one year through five years, Fair Value	12,197
Due after five years through ten years, Fair Value	7,041
Due after ten years, Fair Value	2,545
Debt Securities, Available-for-sale	31,433	28,424
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost	145
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	180
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	102
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Amortized Cost	172
Held-to-maturity securities, Amortized Cost	599	536
Held-to-maturity Securities, Debt Maturities, within One Year, Fair Value	145
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	178
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	101
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	173
Debt Securities, Held-to-maturity, Fair Value	597	536
U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Mortgage-backed securities, Amortized Cost	4,846
Total debt securities - available-for-sale, Amortized Cost	4,846	3,942
Mortgage-backed securities, Fair Value	4,676
Debt Securities, Available-for-sale	4,676	3,911
Non-U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Mortgage-backed securities, Amortized Cost	1,329
Total debt securities - available-for-sale, Amortized Cost	1,329	1,018
Mortgage-backed securities, Fair Value	1,299
Debt Securities, Available-for-sale	$ 1,299	$ 1,015

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, 2018	Dec. 31, 2017
Debt Securities [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	$ 19,147	$ 11,817
Less Than 12 Months, Gross Unrealized Losses	(316)	(67)
Greater Than 12 Months, Fair Value	7,074	4,441
Greater Than 12 Months, Gross Unrealized Losses	(281)	(86)
Total, Fair Value	26,221	16,258
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(597)	(153)
U.S. Government and Agency Obligations [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	2,025	1,249
Less Than 12 Months, Gross Unrealized Losses	(33)	(8)
Greater Than 12 Months, Fair Value	1,068	1,027
Greater Than 12 Months, Gross Unrealized Losses	(43)	(22)
Total, Fair Value	3,093	2,276
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(76)	(30)
State and Municipal Obligations [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	3,471	2,599
Less Than 12 Months, Gross Unrealized Losses	(54)	(21)
Greater Than 12 Months, Fair Value	1,596	866
Greater Than 12 Months, Gross Unrealized Losses	(58)	(14)
Total, Fair Value	5,067	3,465
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(112)	(35)
Corporate Obligations [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	9,933	5,901
Less Than 12 Months, Gross Unrealized Losses	(136)	(23)
Greater Than 12 Months, Fair Value	2,334	1,242
Greater Than 12 Months, Gross Unrealized Losses	(72)	(21)
Total, Fair Value	12,267	7,143
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(208)	(44)
U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	2,762	1,657
Less Than 12 Months, Gross Unrealized Losses	(74)	(12)
Greater Than 12 Months, Fair Value	1,811	1,162
Greater Than 12 Months, Gross Unrealized Losses	(97)	(26)
Total, Fair Value	4,573	2,819
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	(171)	(38)
Non-U.S. Agency Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Less Than 12 Months, Fair Value	956	411
Less Than 12 Months, Gross Unrealized Losses	(19)	(3)
Greater Than 12 Months, Fair Value	265	144
Greater Than 12 Months, Gross Unrealized Losses	(11)	(3)
Total, Fair Value	1,221	555
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (30)	$ (6)

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
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, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 10,263	$ 11,981
Debt Securities, Available-for-sale	31,433	28,424
Equity Securities, Fair Value	1,998	1,992
Assets under management	2,936	3,101
Assets, Fair Value Disclosure	46,630	45,498
Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	31,433	28,424
U.S. Government and Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	3,215	2,644
State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	6,880	7,660
Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	15,363	13,194
U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	4,676	3,911
Non-U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	1,299	1,015
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	10,220	11,718
Equity Securities, Fair Value	1,885	1,784
Assets under management	993	1,117
Assets, Fair Value Disclosure	16,067	17,112
Quoted Prices in Active Markets (Level 1) [Member] | Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	2,969	2,493
Quoted Prices in Active Markets (Level 1) [Member] | U.S. Government and Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	2,928	2,428
Quoted Prices in Active Markets (Level 1) [Member] | State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Quoted Prices in Active Markets (Level 1) [Member] | Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	41	65
Quoted Prices in Active Markets (Level 1) [Member] | U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Quoted Prices in Active Markets (Level 1) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	43	263
Equity Securities, Fair Value	13	14
Assets under management	1,939	1,984
Assets, Fair Value Disclosure	30,300	28,052
Other Observable Inputs (Level 2) [Member] | Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	28,305	25,791
Other Observable Inputs (Level 2) [Member] | U.S. Government and Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	287	216
Other Observable Inputs (Level 2) [Member] | State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	6,880	7,660
Other Observable Inputs (Level 2) [Member] | Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	15,163	12,989
Other Observable Inputs (Level 2) [Member] | U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	4,676	3,911
Other Observable Inputs (Level 2) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	1,299	1,015
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	100	194
Assets under management	4	0
Assets, Fair Value Disclosure	263	334
Unobservable Inputs (Level 3) [Member] | Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	159	140
Unobservable Inputs (Level 3) [Member] | U.S. Government and Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Unobservable Inputs (Level 3) [Member] | State and Municipal Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Unobservable Inputs (Level 3) [Member] | Corporate Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	159	140
Unobservable Inputs (Level 3) [Member] | U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	0	0
Unobservable Inputs (Level 3) [Member] | Non-U.S. Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Available-for-sale	$ 0	$ 0

Fair Value (Financial Assets _2

Fair Value (Financial Assets and Liabilities, Not Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	$ 597	$ 536
Debt Securities, Held-to-maturity	599	536
Debt and other financing obligations, carrying value	32,199	31,067
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	597	536
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 Securities, Held-to-maturity, Fair Value	257	267
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 Securities, Held-to-maturity, Fair Value	71	4
Fair Value, Measurements, Nonrecurring [Member] | Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value	269	265
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	33,533	31,542
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	34,908	34,504
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	34,908	34,504
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

Medical Costs Payable (Narrativ

Medical Costs Payable (Narrative) (Details) - USD ($) $ in Billions	Sep. 30, 2018	Dec. 31, 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred but Not Reported (IBNR) Claims, Amount	$ 13.8	$ 12.3

Medical Costs Payable Rollforwa

Medical Costs Payable Rollforward (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Medical costs payable, beginning of period	$ 17,871	$ 16,391
Acquisitions	333	76
Reported medical costs:
Current year	108,658	97,519
Prior years	(210)	(690)
Total reported medical costs	108,448	96,829
Medical payments:
Payments for current year	(90,348)	(81,237)
Payments for prior years	(16,454)	(14,096)
Total medical payments	(106,802)	(95,333)
Medical costs payable, end of period	$ 19,850	$ 17,963

Commercial Paper and Long-Ter_3

Commercial Paper and Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Minimum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period	3.10%
Maximum [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate During Period	3.40%
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
Three 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	3 years
364 Day $4.0 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	$ 4,000
Line of Credit Facility, Expiration Period	364 days
Subsidiaries [Member]
Debt Instrument [Line Items]
Other Long-term Debt	$ 1,400	$ 625
Other Long-term Debt, Current	$ 230	$ 107
Commercial Paper [Member]
Debt Instrument [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time	2.10%

Commercial Paper and Long-Ter_4

Commercial Paper and Long-Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Par Value	$ 32,687	$ 31,417
Carrying Value	32,199	31,067
Fair Value	33,574	34,029
Commercial Paper [Member]
Debt Instrument [Line Items]
Par Value	20	150
Carrying Value	20	150
Fair Value	$ 20	150
6.000% notes due February 2018 [Member]
Debt Instrument [Line Items]
Interest Rate	6.00%
Par Value	$ 0	1,100
Unsecured Debt, Current	0	1,101
Fair Value	$ 0	1,106
1.900% notes due July 2018 [Member]
Debt Instrument [Line Items]
Interest Rate	1.90%
Par Value	$ 0	1,500
Unsecured Debt, Current	0	1,499
Fair Value	$ 0	1,501
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
Unsecured Debt, Current	750
Fair Value	$ 747	747
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
Unsecured Debt, Current	500
Fair Value	$ 498	497
2.300% notes due December 2019 [Member]
Debt Instrument [Line Items]
Interest Rate	2.30%
Par Value	$ 500	500
Unsecured Long-term Debt, Noncurrent	492	495
Fair Value	$ 496	501
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	1,497	1,496
Fair Value	1,491	1,517
Floating rate notes due October 2020 [Member]
Debt Instrument [Line Items]
Par Value	300	300
Unsecured Long-term Debt, Noncurrent	299	299
Fair Value	$ 300	300
3.875% notes due October 2020 [Member]
Debt Instrument [Line Items]
Interest Rate	3.875%
Par Value	$ 450	450
Unsecured Long-term Debt, Noncurrent	439	446
Fair Value	$ 456	467
1.950% notes due October 2020 [Member]
Debt Instrument [Line Items]
Interest Rate	1.95%
Par Value	$ 900	900
Unsecured Long-term Debt, Noncurrent	897	895
Fair Value	$ 881	892
4.700% notes due February 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	4.70%
Par Value	$ 400	400
Unsecured Long-term Debt, Noncurrent	395	403
Fair Value	$ 412	425
2.125% notes due March 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	2.125%
Par Value	$ 750	750
Unsecured Long-term Debt, Noncurrent	747	746
Fair Value	732	744
Floating rate notes due June 2021 [Member]
Debt Instrument [Line Items]
Par Value	350	0
Unsecured Long-term Debt, Noncurrent	349	0
Fair Value	$ 350	0
3.150% notes due June 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	3.15%
Par Value	$ 400	0
Unsecured Long-term Debt, Noncurrent	398	0
Fair Value	$ 399	0
3.375% notes due November 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	3.375%
Par Value	$ 500	500
Unsecured Long-term Debt, Noncurrent	481	493
Fair Value	$ 502	516
2.875% notes due December 2021 [Member]
Debt Instrument [Line Items]
Interest Rate	2.875%
Par Value	$ 750	750
Unsecured Long-term Debt, Noncurrent	724	741
Fair Value	$ 741	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	1,031	1,054
Fair Value	$ 1,083	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	997	996
Fair Value	$ 999	1,033
2.375% notes due October 2022 [Member]
Debt Instrument [Line Items]
Interest Rate	2.375%
Par Value	$ 900	900
Unsecured Long-term Debt, Noncurrent	894	893
Fair Value	$ 863	891
0.000% notes due November 2022 [Member]
Debt Instrument [Line Items]
Interest Rate	0.00%
Par Value	$ 15	15
Unsecured Long-term Debt, Noncurrent	12	12
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	588	606
Fair Value	$ 606	626
2.875% notes due March 2023 [Member]
Debt Instrument [Line Items]
Interest Rate	2.875%
Par Value	$ 750	750
Unsecured Long-term Debt, Noncurrent	734	762
Fair Value	$ 731	759
3.500% notes due June 2023 [Member]
Debt Instrument [Line Items]
Interest Rate	3.50%
Par Value	$ 750	0
Unsecured Long-term Debt, Noncurrent	746	0
Fair Value	$ 752	0
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	1,989	1,987
Fair Value	$ 2,010	2,108
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	995
Fair Value	$ 961	1,007
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	$ 734	776
3.375% notes due April 2027 [Member]
Debt Instrument [Line Items]
Interest Rate	3.375%
Par Value	$ 625	625
Unsecured Long-term Debt, Noncurrent	619	618
Fair Value	$ 607	642
2.950% notes due October 2027 [Member]
Debt Instrument [Line Items]
Interest Rate	2.95%
Par Value	$ 950	950
Unsecured Long-term Debt, Noncurrent	938	937
Fair Value	$ 890	947
3.850% notes due June 2028 [Member]
Debt Instrument [Line Items]
Interest Rate	3.85%
Par Value	$ 1,150	0
Unsecured Long-term Debt, Noncurrent	1,142	0
Fair Value	$ 1,153	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	$ 1,064	1,165
5.800% notes due March 2036 [Member]
Debt Instrument [Line Items]
Interest Rate	5.80%
Par Value	$ 850	850
Unsecured Long-term Debt, Noncurrent	838	837
Fair Value	$ 1,013	1,105
6.500% notes due June 2037 [Member]
Debt Instrument [Line Items]
Interest Rate	6.50%
Par Value	$ 500	500
Unsecured Long-term Debt, Noncurrent	492	491
Fair Value	$ 640	698
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	641
Fair Value	$ 844	923
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	1,076	1,075
Fair Value	$ 1,467	1,596
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	$ 358	389
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	$ 428	466
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	$ 630	685
4.375% notes due March 2042 [Member]
Debt Instrument [Line Items]
Interest Rate	4.375%
Par Value	$ 502	502
Unsecured Long-term Debt, Noncurrent	484	483
Fair Value	$ 510	555
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	607
Fair Value	$ 596	650
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	$ 749	822
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	$ 2,140	2,362
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	738
Fair Value	$ 743	808
4.250% notes due April 2047 [Member]
Debt Instrument [Line Items]
Interest Rate	4.25%
Par Value	$ 725	725
Unsecured Long-term Debt, Noncurrent	717	717
Fair Value	$ 728	798
3.750% notes due October 2047 [Member]
Debt Instrument [Line Items]
Interest Rate	3.75%
Par Value	$ 950	950
Unsecured Long-term Debt, Noncurrent	933	933
Fair Value	$ 883	969
4.250% notes due June 2048 [Member]
Debt Instrument [Line Items]
Interest Rate	4.25%
Par Value	$ 1,350	0
Unsecured Long-term Debt, Noncurrent	1,329	0
Fair Value	$ 1,355	$ 0

Shareholders' Equity (Details)

Shareholders' Equity (Details) shares in Millions	Jun. 01, 2018shares
Class of Stock [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	100

Shareholders' Equity Share Repu

Shareholders' Equity Share Repurchases (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Class of Stock [Line Items]
Common share repurchases, shares	16
Common share repurchases, average price per share	$ 232.61
Common share repurchases, aggregate cost	$ 3,650	$ 1,173
Board authorized shares remaining	98

Shareholders' Equity Dividends

Shareholders' Equity Dividends (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 18, 2018	Jun. 26, 2018	Mar. 20, 2018	Sep. 30, 2018	Sep. 30, 2017
Class of Stock [Line Items]
Common Stock, Dividends, Per Share, Cash Paid	$ 0.90	$ 0.90	$ 0.75	$ 2.55	$ 2.125
Payments of Ordinary Dividends, Common Stock	$ 866	$ 866	$ 722	$ 2,454	$ 2,046

Segment Financial Information_3

Segment Financial Information (Narrative) (Details)	9 Months Ended
	Sep. 30, 2018
Statement [Line Items]
Number of Reportable Segments	4

Segment Financial Information_4

Segment Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement [Line Items]
Premiums, revenues - unaffiliated customers	$ 44,613	$ 39,552	$ 133,155	$ 118,075
Products, revenues - unaffiliated customers	7,344	6,665	21,050	19,209
Services, revenues - unaffiliated customers	4,217	3,858	12,590	11,089
Investment and other income	382	247	1,035	725
Total revenues	56,556	50,322	167,830	149,098
Earnings from operations	4,590	4,088	12,847	11,232
Interest expense	(353)	(294)	(1,026)	(878)
Earnings before income taxes	4,237	3,794	11,821	10,354
Optum
Statement [Line Items]
Investment and other income	140	94	402	247
Total revenues	25,391	22,885	73,718	66,793
Earnings from operations	2,031	1,697	5,531	4,496
Interest expense	0	0	0	0
Earnings before income taxes	2,031	1,697	5,531	4,496
Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	44,613	39,552	133,155	118,075
Products, revenues - unaffiliated customers	7,344	6,665	21,050	19,209
Services, revenues - unaffiliated customers	4,217	3,858	12,590	11,089
Total revenues	56,174	50,075	166,795	148,373
Unaffiliated Customers | Optum
Statement [Line Items]
Premiums, revenues - unaffiliated customers	985	976	2,794	2,780
Products, revenues - unaffiliated customers	7,344	6,665	21,050	19,209
Services, revenues - unaffiliated customers	2,150	1,853	6,342	5,204
Total revenues	10,479	9,494	30,186	27,193
Affiliated Customers
Statement [Line Items]
Total revenues	0	0	0	0
Affiliated Customers | Optum
Statement [Line Items]
Total revenues	14,772	13,297	43,130	39,353
Operating Segments | UnitedHealthcare
Statement [Line Items]
Investment and other income	242	153	633	478
Total revenues	45,937	40,734	137,242	121,658
Earnings from operations	2,559	2,391	7,316	6,736
Interest expense	0	0	0	0
Earnings before income taxes	2,559	2,391	7,316	6,736
Operating Segments | OptumHealth
Statement [Line Items]
Investment and other income	125	88	355	231
Total revenues	6,052	5,252	17,752	15,107
Earnings from operations	622	513	1,680	1,267
Interest expense	0	0	0	0
Earnings before income taxes	622	513	1,680	1,267
Operating Segments | OptumInsight
Statement [Line Items]
Investment and other income	4	1	15	3
Total revenues	2,254	2,004	6,508	5,840
Earnings from operations	534	414	1,382	1,080
Interest expense	0	0	0	0
Earnings before income taxes	534	414	1,382	1,080
Operating Segments | OptumRx
Statement [Line Items]
Investment and other income	11	5	32	13
Total revenues	17,437	15,953	50,484	46,740
Earnings from operations	875	770	2,469	2,149
Interest expense	0	0	0	0
Earnings before income taxes	875	770	2,469	2,149
Operating Segments | Unaffiliated Customers | UnitedHealthcare
Statement [Line Items]
Premiums, revenues - unaffiliated customers	43,628	38,576	130,361	115,295
Products, revenues - unaffiliated customers	0	0	0	0
Services, revenues - unaffiliated customers	2,067	2,005	6,248	5,885
Total revenues	45,695	40,581	136,609	121,180
Operating Segments | Unaffiliated Customers | OptumHealth
Statement [Line Items]
Premiums, revenues - unaffiliated customers	985	976	2,794	2,780
Products, revenues - unaffiliated customers	13	10	37	33
Services, revenues - unaffiliated customers	1,196	1,040	3,587	2,769
Total revenues	2,194	2,026	6,418	5,582
Operating Segments | Unaffiliated Customers | OptumInsight
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0	0
Products, revenues - unaffiliated customers	29	29	72	69
Services, revenues - unaffiliated customers	790	677	2,306	2,011
Total revenues	819	706	2,378	2,080
Operating Segments | Unaffiliated Customers | OptumRx
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0	0
Products, revenues - unaffiliated customers	7,302	6,626	20,941	19,107
Services, revenues - unaffiliated customers	164	136	449	424
Total revenues	7,466	6,762	21,390	19,531
Operating Segments | Affiliated Customers | UnitedHealthcare
Statement [Line Items]
Total revenues	0	0	0	0
Operating Segments | Affiliated Customers | OptumHealth
Statement [Line Items]
Total revenues	3,733	3,138	10,979	9,294
Operating Segments | Affiliated Customers | OptumInsight
Statement [Line Items]
Total revenues	1,431	1,297	4,115	3,757
Operating Segments | Affiliated Customers | OptumRx
Statement [Line Items]
Total revenues	9,960	9,186	29,062	27,196
Optum Eliminations
Statement [Line Items]
Investment and other income	0	0	0	0
Total revenues	(352)	(324)	(1,026)	(894)
Earnings from operations	0	0	0	0
Interest expense	0	0	0	0
Earnings before income taxes	0	0	0	0
Optum Eliminations | Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0	0
Products, revenues - unaffiliated customers	0	0	0	0
Services, revenues - unaffiliated customers	0	0	0	0
Total revenues	0	0	0	0
Optum Eliminations | Affiliated Customers
Statement [Line Items]
Total revenues	(352)	(324)	(1,026)	(894)
Corporate and Eliminations
Statement [Line Items]
Investment and other income	0	0	0	0
Total revenues	(14,772)	(13,297)	(43,130)	(39,353)
Earnings from operations	0	0	0	0
Interest expense	(353)	(294)	(1,026)	(878)
Earnings before income taxes	(353)	(294)	(1,026)	(878)
Corporate and Eliminations | Unaffiliated Customers
Statement [Line Items]
Premiums, revenues - unaffiliated customers	0	0	0	0
Products, revenues - unaffiliated customers	0	0	0	0
Services, revenues - unaffiliated customers	0	0	0	0
Total revenues	0	0	0	0
Corporate and Eliminations | Affiliated Customers
Statement [Line Items]
Total revenues	$ (14,772)	$ (13,297)	$ (43,130)	$ (39,353)