Centene (CNC) 10-Q 28 Apr 20 2020 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2020	Apr. 17, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2020
Document Transition Report	false
Entity File Number	001-31826
Entity Registrant Name	CENTENE CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	42-1406317
Entity Address, Address Line One	7700 Forsyth Boulevard
Entity Address, City or Town	St. Louis,
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	63105
City Area Code	314
Local Phone Number	725-4477
Title of 12(b) Security	Common Stock $0.001 Par Value
Trading Symbol	CNC
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		579,129,418
Entity Central Index Key	0001071739
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 9,308	$ 12,123
Premium and trade receivables	11,304	6,247
Short-term investments	1,386	863
Other current assets	2,698	1,090
Total current assets	24,696	20,323
Long-term investments	10,521	7,717
Restricted deposits	1,014	658
Property, software and equipment, net	2,439	2,121
Goodwill	17,417	6,863
Intangible assets, net	8,898	2,063
Other long-term assets	1,446	1,249
Total assets	66,431	40,994
Current liabilities:
Medical claims liability	11,413	7,473
Accounts payable and accrued expenses	8,531	4,164
Return of premium payable	1,052	824
Unearned revenue	526	383
Current portion of long-term debt	129	88
Total current liabilities	21,651	12,932
Long-term debt	17,150	13,638
Other long-term liabilities	3,938	1,732
Total liabilities	42,739	28,302
Commitments and contingencies
Redeemable noncontrolling interests	36	33
Stockholders’ equity:
Preferred stock, $0.001 par value; authorized 10,000 shares; no shares issued or outstanding at March 31, 2020 and December 31, 2019	0	0
Common stock, $0.001 par value; authorized 800,000 shares; 594,890 issued and 579,122 outstanding at March 31, 2020, and 421,508 issued and 415,048 outstanding at December 31, 2019	0	0
Additional paid-in capital	19,279	7,647
Accumulated other comprehensive earnings (loss)	(5)	134
Retained earnings	5,030	4,984
Treasury stock, at cost (15,768 and 6,460 shares, respectively)	(755)	(214)
Total Centene stockholders’ equity	23,549	12,551
Nonredeemable Noncontrolling interest	107	108
Total stockholders’ equity	23,656	12,659
Total liabilities, redeemable noncontrolling interests and stockholders’ equity	$ 66,431	$ 40,994

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2020	Dec. 31, 2019
Stockholders' equity
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	800,000,000	800,000,000
Common stock, shares issued (in shares)	594,890,000	421,508,000
Common stock, shares outstanding (in shares)	579,122,000	415,048,000
Treasury stock (in shares)	15,768,000	6,460,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues:
Premium and service revenues	$ 24,172	$ 16,838
Premium tax and health insurer fee	1,853	1,606
Total revenues	26,025	18,444
Expenses:
Medical costs	20,420	13,882
Cost of services	825	544
Selling, general and administrative expenses	2,384	1,609
Amortization of acquired intangible assets	166	65
Premium tax expense	1,625	1,659
Health insurer fee expense	345	0
Impairment	72	0
Total operating expenses	25,837	17,759
Earnings from operations	188	685
Other income (expense):
Investment and other income	167	99
Debt extinguishment costs	(44)	0
Interest expense	(180)	(99)
Earnings from operations, before income tax expense	131	685
Income tax expense	85	166
Net earnings	46	519
Loss attributable to noncontrolling interests	0	3
Net earnings attributable to Centene Corporation	$ 46	$ 522
Net earnings per common share attributable to Centene Corporation:
Basic earnings per common share (in dollars per share)	$ 0.08	$ 1.26
Diluted earnings per common share (in dollars per share)	$ 0.08	$ 1.24
Weighted average number of common shares outstanding:
Basic (in shares)	544,436	412,924
Diluted (in shares)	552,062	419,752
Premium
Revenues:
Premium and service revenues	$ 23,214	$ 16,203
Service
Revenues:
Premium and service revenues	$ 958	$ 635

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE EARNINGS (LOSS) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net earnings	$ 46	$ 519
Change in unrealized gain on investments, net of tax	(134)	94
Defined benefit pension plan net gain, net of tax	2	0
Foreign currency translation adjustments	(7)	0
Other comprehensive earnings (loss)	(139)	94
Comprehensive earnings (loss)	(93)	613
Comprehensive (earnings) loss attributable to noncontrolling interests	0	3
Comprehensive earnings (loss) attributable to Centene Corporation	$ (93)	$ 616

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock	Non-redeemable Non- controlling Interest
Balance (in shares) at Dec. 31, 2018		417,695
Balance at Dec. 31, 2018	$ 11,013	$ 0	$ 7,449	$ (56)	$ 3,663	$ (139)	$ 96
Treasury stock (in shares) at Dec. 31, 2018						5,217
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	520				522		(2)
Other comprehensive earnings (loss), net of tax	94			94
Common stock issued for employee benefit plans (in shares)		1,363
Common stock issued for employee benefit plans	4		4
Common stock repurchases (in shares)						536
Common stock repurchases	(35)					$ (35)
Stock compensation expense	38		38
Balance (in shares) at Mar. 31, 2019		419,058
Balance at Mar. 31, 2019	$ 11,634	$ 0	7,491	38	4,185	$ (174)	94
Treasury stock (in shares) at Mar. 31, 2019						5,753
Balance (in shares) at Dec. 31, 2019	415,048	421,508
Balance at Dec. 31, 2019	$ 12,659	$ 0	7,647	134	4,984	$ (214)	108
Treasury stock (in shares) at Dec. 31, 2019	6,460					6,460
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	$ 43				46		(3)
Other comprehensive earnings (loss), net of tax	(139)			(139)
Common stock issued for acquisitions (in shares)		171,225
Common stock issued for acquisitions	11,526	$ 0	11,526
Common stock issued for employee benefit plans (in shares)		2,448
Common stock issued for employee benefit plans	5		5
Common stock repurchases (in shares)		291				9,308
Common stock repurchases	(558)		(17)			$ (541)
Stock compensation expense	117		117
Contribution from noncontrolling interest	2						2
Other	$ 1		1				0
Balance (in shares) at Mar. 31, 2020	579,122	594,890
Balance at Mar. 31, 2020	$ 23,656	$ 0	$ 19,279	$ (5)	$ 5,030	$ (755)	$ 107
Treasury stock (in shares) at Mar. 31, 2020	15,768					15,768

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Par value (in dollars per share)	$ 0.001		$ 0.001
Other comprehensive earning (loss), tax (benefit)	$ 40	$ 30
Common Stock
Par value (in dollars per share)	$ 0.001	$ 0.001	0.001	$ 0.001
Treasury Stock
Par value (in dollars per share)	$ 0.001	$ 0.001	$ 0.001	$ 0.001

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net earnings	$ 46	$ 519
Adjustments to reconcile net earnings to net cash provided by operating activities
Depreciation and amortization	288	155
Stock compensation expense	117	38
Impairment	72	0
Loss on debt extinguishment	44	0
Deferred income taxes	112	23
Gain on divestiture	(93)	0
Other adjustments, net	24	(11)
Changes in assets and liabilities
Premium and trade receivables	(2,182)	(662)
Other assets	97	20
Medical claims liabilities	252	548
Unearned revenue	(88)	(22)
Accounts payable and accrued expenses	704	357
Other long-term liabilities	361	347
Other operating activities, net	6	4
Net cash (used in) provided by operating activities	(240)	1,316
Cash flows from investing activities:
Capital expenditures	(177)	(176)
Purchases of investments	(1,400)	(580)
Sales and maturities of investments	902	383
Acquisitions, net of cash acquired	(3,048)	0
Divestiture proceeds, net of divested cash	456	0
Other investing activities, net	(5)	0
Net cash used in investing activities	(3,272)	(373)
Cash flows from financing activities:
Proceeds from long-term debt	2,542	1,018
Payments of long-term debt	(1,039)	(927)
Common stock repurchases	(558)	(35)
Payments for debt extinguishment	(21)	0
Debt issuance costs	(92)	0
Other financing activities, net	7	2
Net cash provided by financing activities	839	58
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(1)	0
Net increase (decrease)	(2,674)	1,001
Cash, cash equivalents, and restricted cash and cash equivalents, beginning of period	12,131	5,350
Cash, cash equivalents, and restricted cash and cash equivalents, end of period	9,457	6,351
Supplemental disclosures of cash flow information:
Interest paid	104	87
Income taxes paid	3	6
Equity issued in connection with acquisitions	11,526	0
The following table provides a reconciliation of cash, cash equivalents, and restricted cash and cash equivalents reported within the Consolidated Balance Sheets to the totals above:
Cash and cash equivalents	9,308	6,345
Restricted cash and cash equivalents, included in restricted deposits	149	6
Total cash, cash equivalents, and restricted cash and cash equivalents	$ 9,457	$ 6,351

Organization and Operations

Organization and Operations	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Operations	Organization and Operations Basis of Presentation The accompanying interim financial statements have been prepared under the presumption that users of the interim financial information have either read or have access to the audited financial statements included in the Form 10-K for the fiscal year ended December 31, 2019 . The unaudited interim financial statements herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Accordingly, footnote disclosures that would substantially duplicate the disclosures contained in the December 31, 2019 audited financial statements have been omitted from these interim financial statements, where appropriate. In the opinion of management, these financial statements reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair presentation of the results of the interim periods presented. Certain 2019 amounts in the consolidated financial statements and notes to the consolidated financial statements have been reclassified to conform to the 2020 presentation. These reclassifications have no effect on net earnings or stockholders' equity as previously reported. On January 23, 2020 , the Company acquired all of the issued and outstanding shares of WellCare Health Plans, Inc. (WellCare) (the WellCare Acquisition). The acquisition was accounted for as a business combination. See Note 2. Acquisitions for further details. Recently Adopted Accounting Guidance In June 2016, the Financial Accounting Standards Board (FASB) issued an Accounting Standards Update (ASU) which changes how entities measure credit losses for most financial assets and certain other investments that are not measured at fair value through net income. The ASU is intended to improve financial reporting by requiring timelier recording of credit losses on loans and other financial instruments held by financial institutions and other organizations. The amended guidance requires the measurement of all expected credit losses for financial assets (or groups of financial assets) and available for sale debt securities held at the reporting date over the remaining life based on historical experience, current conditions, and reasonable and supportable forecasts. The guidance is effective for annual and interim periods beginning after December 15, 2019. The Company adopted the new guidance in the first quarter of 2020. The majority of the Company’s receivables and other financial instruments are with government entities and, therefore, the adoption did not have a material impact on its receivables and other financial instruments. The Company evaluated its investment portfolio under the new available-for-sale debt securities impairment model guidance. The vast majority of the Company’s investment portfolio are low risk, investment grade securities. The impact of our evaluation of the investment portfolio resulted in an immaterial decrease to retained earnings at January 1, 2020. The Company evaluates available-for-sale debt securities on a regular basis and records an allowance for credit losses, if necessary. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. The new guidance did not have a material impact on the Company’s consolidated financial position, results of operations or cash flows. In August 2018, the FASB issued an ASU which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by the amendments in this update. The amendments in this ASU require an entity that is the customer in a hosting arrangement to follow the guidance on internal-use software to determine which implementation costs to capitalize and which costs to expense. The standard also requires an entity that is the customer to expense the capitalized implementation costs of a hosting arrangement over the term of the hosting arrangement. The new guidance requires an entity to present the expense related to the capitalized implementation costs in the same line item in the statement of income as the fees associated with the hosting element of the arrangement and classify payments for capitalized implementation costs in the statement of cash flows in the same manner as payments made for fees associated with the hosting element. The entity is also required to present the capitalized implementation costs in the statement of financial position in the same line item that a prepayment for the fees of the associated hosting arrangement would be presented. The guidance is effective for annual and interim periods beginning after December 15, 2019. The Company adopted the new guidance in the first quarter of 2020. The new guidance did not have a material impact on the Company's consolidated financial position, results of operations or cash flows. Recent Accounting Guidance Not Yet Adopted In December 2019, the FASB issued an ASU which simplifies the accounting for income taxes by removing certain exceptions to the general principles in ASC Topic 740. The ASU also clarifies and amends certain areas of ASC Topic 740 to improve consistent application of and simplify the generally accepted accounting principles within Topic 740. The guidance is effective for annual and interim periods beginning after December 15, 2020. The Company is currently evaluating the potential impact of the ASU on the Company's consolidated financial position, results of operations and cash flows.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2020
Business Combinations [Abstract]
Acquisitions	Acquisitions WellCare Acquisition On January 23, 2020 , the Company acquired all of the issued and outstanding shares of WellCare. The transaction was valued at $19,555 million , including the assumption of debt. The WellCare Acquisition brings a high-quality Medicare platform and further extends our robust Medicaid offerings. The WellCare Acquisition also enables us to provide access to more comprehensive and differentiated solutions across more markets with a continued focus on affordable, high-quality, culturally-sensitive healthcare services. With the WellCare Acquisition, we further broadened our product offerings by adding a Medicare prescription drug plan to our existing business lines. Total consideration paid for the acquisition was $17,605 million , consisting of Centene common shares valued at $11,431 million (based on Centene's stock price of $66.76 ), $6,079 million in cash, and $95 million related to the fair value of replacement equity awards associated with pre-combination service. Each WellCare share was converted into 3.38 of validly issued, fully paid, non-assessable shares of Centene common stock and $120.00 in cash. In total, 171 million shares of Centene common stock were issued to the WellCare stockholders. The cash portion of the acquisition was funded through the issuance of long-term debt as further discussed in Note 7. Debt . The Company also recognized $313 million of acquisition related costs, primarily related to WellCare, that were in the consolidated statement of operations for the three months ended March 31, 2020 . The acquisition of WellCare was accounted for as a business combination using the acquisition method of accounting that requires assets acquired and liabilities assumed to be recognized at fair value as of the acquisition date. Due to the timing of the acquisition, the valuation of the assets acquired and liabilities assumed has not yet been finalized, and as a result, the preliminary estimates have been recorded and are subject to change. Any necessary adjustments from our preliminary estimates will be finalized within one year from the date of acquisition. Measurement period adjustments will be recorded in the period in which they are determined, as if they had been completed at the acquisition date. The Company's preliminary allocation of the fair value of assets acquired and liabilities assumed as of the acquisition date of January 23, 2020 is as follows ($ in millions): Assets acquired and liabilities assumed Cash and cash equivalents $ 2,899 Premium and related receivables 3,414 Short-term investments 403 Other current assets 1,158 Long-term investments 2,699 Restricted deposits 319 Property, software and equipment 270 Intangible assets (a) 7,000 Other long-term assets 261 Total assets acquired 18,423 Medical claims liability 3,962 Accounts payable and accrued expenses 3,142 Return of premium payable 238 Unearned revenue 223 Long-term debt (b) 2,055 Deferred tax liabilities (c) 1,537 Other long-term liabilities 281 Total liabilities assumed 11,438 Total identifiable net assets 6,985 Goodwill (d) 10,620 Total assets acquired and liabilities assumed $ 17,605 The Company has made the following preliminary fair value adjustments based on information reviewed through March 31, 2020. Significant fair value adjustments are noted as follows: (a) The identifiable intangible assets acquired are to be measured at fair value as of the completion of the acquisition. The fair value of intangible assets will be determined primarily using variations of the income approach, which is based on the present value of the future after tax cash flows attributable to each identified intangible asset. Other valuation methods, including the market approach and cost approach, will be considered in estimating the fair value. The identifiable intangible assets include purchased contract rights, trade names, provider contracts and developed technologies. The Company has estimated the preliminary fair value of intangible assets to be $7,000 million with a weighted average life of 13 years. The preliminary fair values and weighted average useful lives for identifiable intangible assets acquired are as follows: Fair Value Weighted Average Useful Life (in years) Purchased contract rights $ 5,200 Trade names 800 Provider contracts 700 Developed technologies 300 Total intangible assets acquired $ 7,000 13 (b) Debt is required to be measured at fair value under the acquisition method of accounting. The fair value of WellCare's aggregate principle of $1,950 million Senior Notes assumed in the acquisition was $2,055 million . The $105 million increase will be amortized as a reduction to interest expense over the remaining life of the debt. (c) The preliminary deferred tax liabilities are presented net of $408 million of deferred tax assets. (d) The acquisition resulted in $10.6 billion of goodwill related primarily to synergies expected from the acquisition and the assembled workforce of WellCare. The assignment of goodwill to the Company's respective segments has not been completed at this time, but the majority of goodwill is expected to be allocated to the Managed Care segment. The majority of the goodwill is not deductible for income tax purposes. Divestitures Immediately prior to the closing of the WellCare Acquisition , Anthem, Inc. acquired WellCare's Missouri Medicaid health plan, a WellCare Missouri Medicare Advantage health plan, and WellCare's Nebraska Medicaid health plan. CVS Health Corporation acquired portions of Centene's Illinois Medicaid and Medicare Advantage health plans as part of previously announced divestiture agreements. The Company recorded a $93 million pre-tax gain as a result of the Illinois divestiture, which is included in investment and other income on the Consolidated Statements of Operations. Unaudited Pro Forma Financial Information The following table presents supplemental pro forma information for the three months ended March 31, 2019 ($ in millions, except per share data): Three Months Ended Total revenues $ 25,169 Net earnings attributable to common stockholders $ 552 Diluted earnings per share $ 0.93 The unaudited pro forma total revenues for the three months ended March 31, 2020 were $27,815 million . It is impracticable for the Company to determine the pro forma earnings information for the three months ended March 31, 2020 due to the nature of obtaining that information as the Company immediately began integrating WellCare into its ongoing operations. The unaudited pro forma financial information reflects the historical results of Centene and WellCare adjusted as if the acquisition had occurred on January 1, 2019, primarily for the following: • Interest expense associated with debt incurred to finance the transaction. • Elimination of historical WellCare intangible asset amortization expense and addition of amortization expense based on the preliminary estimated values of identifiable intangible assets of approximately $7.0 billion . • Issuance of 171 million shares of Centene common stock in connection with the per share common stock consideration. • Elimination of acquisition related costs. • Adjustments to income tax expense related to pro forma adjustments and increased income tax expense related to IRS Regulation 162(m)(6).

Short-term and Long-term Invest

Short-term and Long-term Investments, Restricted Deposits	3 Months Ended
	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Short-term and Long-term Investments, Restricted Deposits	Short-term and Long-term Investments, Restricted Deposits Short-term and long-term investments and restricted deposits by investment type consist of the following ($ in millions): March 31, 2020 December 31, 2019 Amortized Cost Gross Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Fair Value Debt securities: U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 771 $ 7 $ — $ 778 $ 211 $ 1 $ — $ 212 Corporate securities 5,036 76 (134 ) 4,978 3,629 108 (4 ) 3,733 Restricted certificates of deposit 153 — — 153 482 — — 482 Restricted cash equivalents 149 — — 149 8 — — 8 Short-term time deposits 84 — — 84 — — — — Municipal securities 2,511 77 (4 ) 2,584 2,320 69 (1 ) 2,388 Asset-backed securities 1,050 4 (36 ) 1,018 741 5 (2 ) 744 Residential mortgage-backed securities 997 32 (2 ) 1,027 464 8 (1 ) 471 Commercial mortgage-backed securities 590 10 (13 ) 587 380 9 (1 ) 388 Equity securities (1) 685 — — 685 — — — — Private equity investments 748 — — 748 664 — — 664 Life insurance contracts 130 — — 130 148 — — 148 Total $ 12,904 $ 206 $ (189 ) $ 12,921 $ 9,047 $ 200 $ (9 ) $ 9,238 (1) Investments in equity securities primarily consists of exchange traded funds in fixed income securities. The Company’s investments are debt securities classified as available-for-sale with the exception of equity securities, life insurance contracts and certain private equity investments . The Company’s investment policies are designed to provide liquidity, preserve capital and maximize total return on invested assets with the focus on high credit quality securities. The Company limits the size of investment in any single issuer other than U.S. treasury securities and obligations of U.S. government corporations and agencies. As of March 31, 2020 , 97% of the Company’s investments in rated securities carry an investment grade rating by nationally recognized statistical rating organizations. At March 31, 2020 , the Company held certificates of deposit, equity securities, life insurance contracts and private equity investments which did not carry a credit rating. Accrued interest income on available for sale debt securities was $78 million at March 31, 2020, and is included in other current assets on the consolidated balance sheet. The Company's residential mortgage-backed securities are primarily issued by the Federal National Mortgage Association, Government National Mortgage Association or Federal Home Loan Mortgage Corporation, which carry implicit or explicit guarantees of the U.S. government. The Company's commercial mortgage-backed securities are primarily senior tranches with a weighted average rating of AA+ and a weighted average duration of 4 years at March 31, 2020 . The fair value of available-for-sale debt securities with gross unrealized losses by investment type and length of time that individual securities have been in a continuous unrealized loss position were as follows ($ in millions): March 31, 2020 December 31, 2019 Less Than 12 Months 12 Months or More Less Than 12 Months 12 Months or More Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value U.S. Treasury securities and obligations of U.S. government corporations and agencies $ — $ 374 $ — $ — $ — $ 11 $ — $ 31 Corporate securities (130 ) 2,461 (4 ) 16 (2 ) 192 (2 ) 48 Municipal securities (4 ) 275 — 1 (1 ) 185 — 11 Asset-backed securities (30 ) 628 (6 ) 102 (1 ) 153 (1 ) 151 Residential mortgage-backed securities (2 ) 68 — 6 — 44 (1 ) 81 Commercial mortgage-backed securities (13 ) 280 — 3 (1 ) 118 — 21 Short-term time deposits — — — 2 — — — — Total $ (179 ) $ 4,086 $ (10 ) $ 130 $ (5 ) $ 703 $ (4 ) $ 343 As of March 31, 2020 , the gross unrealized losses were generated from 2,636 positions out of a total of 5,998 positions. The change in fair value of fixed income securities is primarily a result of movement in interest rates subsequent to the purchase of the security. For each security in an unrealized loss position, the Company assesses whether it intends to sell the security or if it is more likely than not the Company will be required to sell the security before recovery of the amortized cost basis for reasons such as liquidity, contractual or regulatory purposes. If the security meets this criterion, the decline in fair value is recorded in earnings. The Company does not intend to sell these securities prior to maturity and it is not likely that the Company will be required to sell these securities prior to maturity; therefore, the Company did not record impairment for these securities. In addition, the Company continuously monitors investments for credit losses. Certain investments have experienced a decline in fair value due to changes in credit quality, market interest rates and/or general economic conditions. The Company recognizes an allowance when evidence demonstrates that it is credit related. Evidence of a credit related loss may include rating agency actions, adverse conditions specifically related to the security, or failure of the issuer of the security to make scheduled payments. The contractual maturities of short-term and long-term debt securities and restricted deposits are as follows ($ in millions): March 31, 2020 December 31, 2019 Investments Restricted Deposits Investments Restricted Deposits Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value One year or less $ 1,239 $ 1,237 $ 841 $ 842 $ 750 $ 752 $ 550 $ 550 One year through five years 3,954 3,935 169 172 3,034 3,106 106 108 Five years through ten years 2,430 2,465 — — 2,162 2,257 — — Greater than ten years 72 74 — — 48 50 — — Asset-backed securities 2,636 2,633 — — 1,585 1,603 — — Total $ 10,331 $ 10,344 $ 1,010 $ 1,014 $ 7,579 $ 7,768 $ 656 $ 658 Actual maturities may differ from contractual maturities due to call or prepayment options. Equity securities, private equity investments and life insurance contracts are excluded from the table above because they do not have a contractual maturity. The Company has an option to redeem at amortized cost substantially all of the securities included in the greater than ten years category listed above.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Assets and liabilities recorded at fair value in the Consolidated Balance Sheets are categorized based upon observable or unobservable inputs used to estimate fair value. Level inputs are as follows: Level Input: Input Definition: Level I Inputs are unadjusted, quoted prices for identical assets or liabilities in active markets at the measurement date. Level II Inputs other than quoted prices included in Level I that are observable for the asset or liability through corroboration with market data at the measurement date. Level III Unobservable inputs that reflect management’s best estimate of what market participants would use in pricing the asset or liability at the measurement date. The following table summarizes fair value measurements by level at March 31, 2020 , for assets and liabilities measured at fair value on a recurring basis ($ in millions): Level I Level II Level III Total Assets Cash and cash equivalents $ 9,308 $ — $ — $ 9,308 Investments: U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 114 $ — $ — $ 114 Corporate securities — 4,960 — 4,960 Municipal securities — 2,554 — 2,554 Short-term time deposits — 84 — 84 Asset-backed securities — 1,018 — 1,018 Residential mortgage-backed securities — 1,027 — 1,027 Commercial mortgage-backed securities — 587 — 587 Equity securities 683 2 — 685 Total investments $ 797 $ 10,232 $ — $ 11,029 Restricted deposits: Cash and cash equivalents $ 149 $ — $ — $ 149 Certificates of deposit — 153 — 153 Corporate securities — 18 — $ 18 Municipal securities — 30 — 30 U.S. Treasury securities and obligations of U.S. government corporations and agencies 664 — — 664 Total restricted deposits $ 813 $ 201 $ — $ 1,014 Total assets at fair value $ 10,918 $ 10,433 $ — $ 21,351 The following table summarizes fair value measurements by level at December 31, 2019 , for assets and liabilities measured at fair value on a recurring basis ($ in millions): Level I Level II Level III Total Assets Cash and cash equivalents $ 12,123 $ — $ — $ 12,123 Investments: U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 73 $ — $ — $ 73 Corporate securities — 3,713 — 3,713 Municipal securities — 2,379 — 2,379 Asset-backed securities — 744 — 744 Residential mortgage-backed securities — 471 — 471 Commercial mortgage-backed securities — 388 — 388 Total investments $ 73 $ 7,695 $ — $ 7,768 Restricted deposits: Cash and cash equivalents $ 8 $ — $ — $ 8 Certificates of deposit — 482 — 482 Corporate securities — 20 — 20 Municipal securities — 9 — 9 U.S. Treasury securities and obligations of U.S. government corporations and agencies 139 — — 139 Total restricted deposits $ 147 $ 511 $ — $ 658 Other long-term assets: Interest rate swap agreements $ — $ 10 $ — $ 10 Total assets at fair value $ 12,343 $ 8,216 $ — $ 20,559 Liabilities Other long-term liabilities: Interest rate swap agreements $ — $ 11 $ — $ 11 Total liabilities at fair value $ — $ 11 $ — $ 11 The Company utilizes matrix-pricing services to estimate fair value for securities which are not actively traded on the measurement date. The Company designates these securities as Level II fair value measurements. In addition, the aggregate carrying amount of the Company’s life insurance contracts and other private equity investments , which approximates fair value, was $878 million and $812 million as of March 31, 2020 and December 31, 2019 , respectively.

Medical Claims Liability

Medical Claims Liability	3 Months Ended
	Mar. 31, 2020
Insurance [Abstract]
Medical Claims Liability	Medical Claims Liability The following table summarizes the change in medical claims liability ($ in millions): Three Months Ended March 31, 2020 2019 Balance, January 1 $ 7,473 $ 6,831 Less: Reinsurance recoverable 20 27 Balance, January 1, net 7,453 6,804 Acquisitions and divestitures 3,697 6 Incurred related to: Current year 20,866 14,376 Prior years (446 ) (494 ) Total incurred 20,420 13,882 Paid related to: Current year 15,147 8,771 Prior years 5,031 4,560 Total paid 20,178 13,331 Balance at March 31, net 11,392 7,361 Plus: Reinsurance recoverable 21 20 Balance, March 31 $ 11,413 $ 7,381 Reinsurance recoverables related to medical claims are included in premium and trade receivables. Changes in estimates of incurred claims for prior years are primarily attributable to reserving under moderately adverse conditions. Additionally, as a result of minimum health benefits ratio (HBR) and other return of premium programs, we recorded $31 million as a reduction to premium revenue and $8 million as an increase to premium revenues in the three months ended March 31, 2020 and 2019 , respectively. Incurred but not reported (IBNR) plus expected development on reported claims as of March 31, 2020 was $7,527 million . Total IBNR plus expected development on reported claims represents estimates for claims incurred but not reported, development on reported claims, and estimates for the costs necessary to process unpaid claims at the end of each period. We estimate our liability using actuarial methods that are commonly used by health insurance actuaries and meet Actuarial Standards of Practice. These actuarial methods consider factors such as historical data for payment patterns, cost trends, product mix, seasonality, utilization of healthcare services and other relevant factors.

Affordable Care Act

Affordable Care Act	3 Months Ended
	Mar. 31, 2020
Affordable Care Act [Abstract]
Affordable Care Act	Affordable Care Act The Affordable Care Act established risk spreading premium stabilization programs as well as minimum annual medical loss ratio and cost sharing reductions. The Company's net receivables (payables) for each of the programs are as follows ($ in millions): March 31, 2020 December 31, 2019 Risk adjustment receivable $ 326 $ 245 Risk adjustment payable (1,569 ) (1,239 ) Minimum medical loss ratio (466 ) (367 ) Cost sharing reduction receivable 96 73 Cost sharing reduction payable (1 ) (1 )

Debt

Debt	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Debt	Debt Debt consists of the following ($ in millions): March 31, 2020 December 31, 2019 $1,000 million 4.75% Senior Notes, due May 15, 2022 $ 1,007 $ 1,004 $1,000 million 6.125% Senior Notes, due February 15, 2024 — 1,000 $2,200 million 4.75% Senior Notes, due January 15, 2025 2,236 2,228 $1,200 million 5.250% Senior Notes due April 1, 2025 1,250 — $1,800 million 5.375% Senior Notes, due June 1, 2026 1,800 1,800 $750 million 5.375% Senior Notes due August 15, 2026 800 — $2,500 million 4.25% Senior Notes due December 15, 2027 2,480 2,479 $3,500 million 4.625% Senior Notes due December 15, 2029 3,500 3,500 $2,000 million 3.375% Senior Notes due February 15, 2030 2,000 — Fair value of interest rate swap agreements — (1 ) Total senior notes 15,073 12,010 Term loan credit facility 1,450 1,450 Revolving credit agreement 588 93 Mortgage notes payable 53 54 Construction loan payable 149 140 Finance leases and other 119 122 Debt issuance costs (153 ) (143 ) Total debt 17,279 13,726 Less current portion (129 ) (88 ) Long-term debt $ 17,150 $ 13,638 Senior Notes In February 2020, the Company issued $2,000 million 3.375% Senior Notes due February 15, 2030 (the 2030 Notes). The Company used the net proceeds from the 2030 Notes to redeem all of its outstanding $1,000 million 6.125% Senior Notes, due February 15, 2024 (the 2024 Notes). The Company recognized a pre-tax loss on extinguishment of approximately $44 million , including the call premium, the write-off of unamortized debt issuance costs and the loss on the termination of the $1,000 million interest rate swap associated with the 2024 Notes. The Company also intended to use remaining proceeds to redeem its $1,000 million 4.75% Senior Notes due May 15, 2022 (the 2022 Notes). However, as a result of the spread of COVID-19 and the resulting disruption and volatility in the global capital markets, the Company has deferred the redemption of the 2022 Notes at this time. In connection with the WellCare Acquisition, in January 2020, the Company completed an exchange offer for up to $1,200 million of 5.25% Senior Notes due April 1, 2025 and $750 million of 5.375% Senior Notes due August 15, 2026 (collectively, the WellCare Notes) issued by WellCare and issued $1,146 million aggregate principal amount of 5.25% Senior Notes due April 1, 2025 and $747 million aggregate principal amount of 5.375% Senior Notes due August 15, 2026. Additionally, the Company's wholly owned subsidiary, WellCare Health Plans, Inc., assumed the remaining unexchanged WellCare Notes. The WellCare Notes were recorded at the acquisition date fair value of $2,055 million . Interest Rate Swaps During the three months ended March 31, 2020, the Company terminated the interest rate swap agreements associated with the 2022 Notes and $2,200 million 4.75% Senior Notes, due January 15, 2025, (the 2025 Notes). The interest rate swap associated with the 2024 Notes were also terminated in connection with the redemption of those notes as discussed above. In total, the Company terminated three interest rate swap contracts with a notional amount of $2,100 million . The swaps effectively converted $2,100 million of fixed rate notes to floating rates. As a result of the interest rate swap terminations, the Company received $9 million in cash. The corresponding net gain on the 2022 Notes and 2025 Notes is being amortized as a reduction to interest expense over the remaining term of the respective notes.

Leases

Leases	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
Leases	Leases The Company records right of use (ROU) assets and liabilities for non-cancelable operating leases primarily for real estate and equipment. Leases with an initial term of 12 months or less are not recorded on the balance sheet. Expense related to leases is recorded on a straight-line basis over the lease term, including rent holidays. During the three months ended March 31, 2020 , the Company recognized operating lease expense of $62 million . The following table sets forth the ROU assets and liabilities as of March 31, 2020 ($ in millions): March 31, 2020 Assets ROU assets (recorded within other long-term assets) $ 852 Liabilities Short-term (recorded within accounts payable and accrued expenses) $ 198 Long-term (recorded within other long-term liabilities) 794 Total ROU liabilities $ 992 During the three months ended March 31, 2020 , the Company reduced its ROU liabilities by $63 million , for cash paid. The Company did not have any new operating leases commence during the three months ended March 31, 2020 , that resulted in the recognition of ROU assets and liabilities. As of March 31, 2020 , the Company had additional operating leases that have not yet commenced of $421 million , which included four significant leases executed during the first quarter . These operating leases will commence in 2020 with lease terms of 2 years to 16 years. In connection with the WellCare Acquisition, we acquired approximately $240 million and $260 million of ROU assets and liabilities, respectively. As of March 31, 2020 , the weighted average remaining lease term of the Company's operating leases was 6.8 years. The ROU liabilities as of March 31, 2020 reflect a weighted average discount rate of 4.7% . Lease payments over the next five years and thereafter are as follows ($ in millions): March 31, 2020 2020 $ 177 2021 223 2022 174 2023 140 2024 117 2025 82 Thereafter 258 Total lease payments 1,171 Less: imputed interest (179 ) Total ROU liabilities $ 992

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2020
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity In January 2020, the Company issued 171 million shares of Centene common stock with a fair value of $11,431 million and paid $6,079 million in cash in exchange for all the outstanding shares of WellCare common stock. In addition, the Company recorded $95 million related to the fair value of replacement equity awards associated with pre-combination service. During the three months ended March 31, 2020 , the Company used proceeds from divestitures to repurchase 8,672 thousand shares of Centene common stock for $500 million through the Company's stock repurchase program. As of March 31, 2020 , the Company has a remaining amount of 5,488 thousand shares available under the program. The remaining common stock repurchases during the quarter relate to the purchase of shares to satisfy tax withholding requirements in connection with employee equity awards.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table sets forth the calculation of basic and diluted net earnings per common share ($ in millions, except per share data in dollars and shares in thousands): Three Months Ended March 31, 2020 2019 Earnings attributable to Centene Corporation $ 46 $ 522 Shares used in computing per share amounts: Weighted average number of common shares outstanding 544,436 412,924 Common stock equivalents (as determined by applying the treasury stock method) 7,626 6,828 Weighted average number of common shares and potential dilutive common shares outstanding 552,062 419,752 Net earnings per common share attributable to Centene Corporation: Basic earnings per common share $ 0.08 $ 1.26 Diluted earnings per common share $ 0.08 $ 1.24 The calculation of diluted earnings per common share for the three months ended March 31, 2020 and March 31, 2019 excludes the impact of 400 thousand and 1,400 thousand shares, respectively, related to anti-dilutive stock options, restricted stock and restricted stock units.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Segment Information	Segment Information Centene operates in two segments: Managed Care and Specialty Services. The Managed Care segment consists of Centene’s health plans, including all of the functions needed to operate them. Subsequent to the closing of the WellCare Acquisition, the Managed Care segment also includes WellCare's legacy Medicaid Health Plans, Medicare Health Plans and Medicare Prescription Drug Plan (PDP) segments. The Specialty Services segment consists of Centene’s specialty companies offering auxiliary healthcare services and products. Factors used in determining the reportable business segments include the nature of operating activities, the existence of separate senior management teams, and the type of information presented to the Company's chief operating decision-maker to evaluate all results of operations. Segment information for the three months ended March 31, 2020 , follows ($ in millions): Managed Care Specialty Services Eliminations Consolidated Total Total revenues from external customers $ 24,936 $ 1,089 $ — $ 26,025 Total revenues from internal customers 100 2,814 (2,914 ) — Total revenues $ 25,036 $ 3,903 $ (2,914 ) $ 26,025 Earnings from operations $ 217 $ (29 ) $ — $ 188 Segment information for the three months ended March 31, 2019 , follows ($ in millions): Managed Care Specialty Services Eliminations Consolidated Total Total revenues from external customers $ 17,687 $ 757 $ — $ 18,444 Total revenues from internal customers 35 2,449 (2,484 ) — Total revenues $ 17,722 $ 3,206 $ (2,484 ) $ 18,444 Earnings from operations $ 615 $ 70 $ — $ 685

Contingencies

Contingencies	3 Months Ended
	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Contingencies	Contingencies Overview The Company is routinely subjected to legal and regulatory proceedings in the normal course of business. These matters can include, without limitation: • periodic compliance and other reviews and investigations by various federal and state regulatory agencies with respect to requirements applicable to the Company's business, including, without limitation, those related to payment of out-of-network claims, submissions to CMS for risk adjustment payments or the False Claims Act, submissions to state agencies related to payments or state false claims acts, pre-authorization penalties, timely review of grievances and appeals, timely and accurate payment of claims, and the Health Insurance Portability and Accountability Act of 1996 and other federal and state fraud, waste and abuse laws; • litigation arising out of general business activities, such as tax matters, disputes related to healthcare benefits coverage or reimbursement, putative securities class actions and medical malpractice, privacy, real estate, intellectual property and employment-related claims; • disputes regarding reinsurance arrangements, claims arising out of the acquisition or divestiture of various assets, class actions and claims relating to the performance of contractual and non-contractual obligations to providers, members, employer groups and others, including, but not limited to, the alleged failure to properly pay claims and challenges to the manner in which the Company processes claims and claims alleging that the Company has engaged in unfair business practices. Among other things, these matters may result in awards of damages, fines or penalties, which could be substantial, and/or could require changes to the Company's business. The Company intends to vigorously defend itself against legal and regulatory proceedings to which it is currently a party; however, these proceedings are subject to many uncertainties. In some of the cases pending against the Company, substantial non-economic or punitive damages are being sought. The Company records reserves and accrues costs for certain legal proceedings and regulatory matters to the extent that it determines an unfavorable outcome is probable and the amount of the loss can be reasonably estimated. While such reserves and accrued costs reflect the Company's best estimate of the probable loss for such matters, the recorded amounts may differ materially from the actual amount of any such losses. In some cases, no estimate of the possible loss or range of loss in excess of amounts accrued, if any, can be made because of the inherently unpredictable nature of legal and regulatory proceedings, which may be exacerbated by various factors, including but not limited to, they may involve indeterminate claims for monetary damages or may involve fines, penalties or punitive damages; present novel legal theories or legal uncertainties; involve disputed facts; represent a shift in regulatory policy; involve a large number of parties, claimants or regulatory bodies; are in the early stages of the proceedings; involve a number of separate proceedings and/or a wide range of potential outcomes; or result in a change of business practices. As of the date of this report, amounts accrued for legal proceedings and regulatory matters were not material. However, it is possible that in a particular quarter or annual period the Company's financial condition, results of operations, cash flow and/or liquidity could be materially adversely affected by an ultimate unfavorable resolution of, or development in, legal and/or regulatory proceedings, including as described below. Except for the proceedings discussed below, the Company believes that the ultimate outcome of any of the regulatory and legal proceedings that are currently pending against it should not have a material adverse effect on financial condition, results of operations, cash flow or liquidity. California On October 20, 2015, the Company's California subsidiary, Health Net of California, Inc. (Health Net California), was named as a defendant in a California taxpayer action filed in Los Angeles County Superior Court, captioned as Michael D. Myers v. State Board of Equalization, Dave Jones, Insurance Commissioner of the State of California, Betty T. Yee, Controller of the State of California, et al., Los Angeles Superior Court Case No. BS158655. This action is brought under a California statute that permits an individual taxpayer to sue a governmental agency when the taxpayer believes the agency has failed to enforce governing law. Plaintiff contends that Health Net California, a California licensed Health Care Service Plan (HCSP), is an "insurer" for purposes of taxation despite acknowledging it is not an "insurer" under regulatory law. Under California law, "insurers" must pay a gross premiums tax (GPT), calculated as 2.35% on gross premiums. As a licensed HCSP, Health Net California has paid the California Corporate Franchise Tax (CFT), the tax generally paid by California businesses. Plaintiff contends that Health Net California must pay the GPT rather than the CFT. Plaintiff seeks a writ of mandate directing the California taxing agencies to collect the GPT, and seeks an order requiring Health Net California to pay GPT, interest and penalties for a period dating to eight years prior to the October 2015 filing of the complaint. This lawsuit is being coordinated with similar lawsuits filed against other entities (collectively, "Related Actions"). In March 2018, the Court overruled the Company's demurrer seeking to dismiss the complaint and denied the Company's motion to strike allegations seeking retroactive relief. In August 2018, the trial court stayed all the Related Actions pending determination of a writ of mandate by the California Court of Appeals in two of the Related Actions. In March 2019, the California Court of Appeals denied the writ of mandate. The defendants in those Related Actions sought review by the California Supreme Court, which declined to review the matter. Upon the return of the matter to the Los Angeles County Superior Court, motions for summary judgment were scheduled. Health Net California's motion for summary judgment was heard by the Court on March 4, 2020. On March 29, 2020, the Court granted Health Net California's motion for summary judgment. The plaintiff may or may not appeal the Court's decision. The Company intends to continue its vigorous defense against these claims; however, this matter is subject to many uncertainties, and an adverse outcome in this matter could potentially have a materially adverse impact on the Company's financial position, results of operations and cash flows. Veterans Administration Matter In October 2017, a Civil Investigative Demand (CID) was issued to Health Net Federal Services, LLC (HNFS) by the United States Department of Justice. The CID seeks documents and interrogatory responses concerning whether HNFS submitted, or caused to be submitted, excessive, duplicative or otherwise improper claims to the U.S. Department of Veterans Affairs (VA) under a contract to provide healthcare coordination services for veterans. The contract began in late 2014 and ended September 30, 2018. In 2016, modifications to the contract were made to allow for possible duplicate billings with a reconciliation period at the end of the contract term. The Company is complying with the CID and believes it has met its contractual obligations. At this point, it is not possible to determine what level of liability, if any, the Company may face as a result of this matter. Ambetter Class Action On January 11, 2018, a putative class action lawsuit was filed by Cynthia Harvey and Steven A. Milman against the Company and certain subsidiaries in the U.S. District Court for the Eastern District of Washington. The complaint alleges that the Company failed to meet federal and state requirements for provider networks and directories with regard to its Ambetter policies, denied coverage and/or refused to pay for covered benefits, and failed to address grievances adequately, causing some members to incur unexpected costs. In March 2018, the Company filed separate motions to dismiss each defendant. In July 2018, the plaintiff voluntarily filed a First Amended Complaint that removed Steven Milman as a plaintiff, dropped Centene Corporation and Superior Health Plan as defendants, abandoned certain claims, narrowed the putative class to Washington State only, and added Centene Management Company as a defendant. In August 2018, the Company moved to dismiss the First Amended Complaint. In response, the plaintiff voluntarily filed a Second Amended Complaint. In September 2018, the Company filed a motion to dismiss the Second Amended Complaint. On November 21, 2018, the Court granted in part and denied in part the Company's motion to dismiss. Plaintiff Cynthia Harvey filed a Third Amended Complaint, on November 28, 2018, against Centene Management Company and Coordinated Care Corporation (Defendants), both subsidiaries of the Company. Defendants filed an answer on December 12, 2018. The plaintiffs filed a motion for class certification on January 8, 2020. The hearing on that motion is scheduled for May 12, 2020. The Company intends to vigorously defend itself against these claims. Nevertheless, this matter is subject to many uncertainties and the Company cannot predict how long this litigation will last or what the ultimate outcome will be, and an adverse outcome in this matter could potentially have a materially adverse impact on the Company's financial position and results of operations.

Organization and Operations (Po

Organization and Operations (Policies)	3 Months Ended
	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim financial statements have been prepared under the presumption that users of the interim financial information have either read or have access to the audited financial statements included in the Form 10-K for the fiscal year ended December 31, 2019 . The unaudited interim financial statements herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission. Accordingly, footnote disclosures that would substantially duplicate the disclosures contained in the December 31, 2019 audited financial statements have been omitted from these interim financial statements, where appropriate. In the opinion of management, these financial statements reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for a fair presentation of the results of the interim periods presented. Certain 2019 amounts in the consolidated financial statements and notes to the consolidated financial statements have been reclassified to conform to the 2020 presentation. These reclassifications have no effect on net earnings or stockholders' equity as previously reported. On January 23, 2020 , the Company acquired all of the issued and outstanding shares of WellCare Health Plans, Inc. (WellCare) (the WellCare Acquisition). The acquisition was accounted for as a business combination. See Note 2. Acquisitions for further details.
Recently Adopted Accounting Guidance and Accounting Guidance Not Yet Adopted	Recently Adopted Accounting Guidance In June 2016, the Financial Accounting Standards Board (FASB) issued an Accounting Standards Update (ASU) which changes how entities measure credit losses for most financial assets and certain other investments that are not measured at fair value through net income. The ASU is intended to improve financial reporting by requiring timelier recording of credit losses on loans and other financial instruments held by financial institutions and other organizations. The amended guidance requires the measurement of all expected credit losses for financial assets (or groups of financial assets) and available for sale debt securities held at the reporting date over the remaining life based on historical experience, current conditions, and reasonable and supportable forecasts. The guidance is effective for annual and interim periods beginning after December 15, 2019. The Company adopted the new guidance in the first quarter of 2020. The majority of the Company’s receivables and other financial instruments are with government entities and, therefore, the adoption did not have a material impact on its receivables and other financial instruments. The Company evaluated its investment portfolio under the new available-for-sale debt securities impairment model guidance. The vast majority of the Company’s investment portfolio are low risk, investment grade securities. The impact of our evaluation of the investment portfolio resulted in an immaterial decrease to retained earnings at January 1, 2020. The Company evaluates available-for-sale debt securities on a regular basis and records an allowance for credit losses, if necessary. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. The new guidance did not have a material impact on the Company’s consolidated financial position, results of operations or cash flows. In August 2018, the FASB issued an ASU which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The accounting for the service element of a hosting arrangement that is a service contract is not affected by the amendments in this update. The amendments in this ASU require an entity that is the customer in a hosting arrangement to follow the guidance on internal-use software to determine which implementation costs to capitalize and which costs to expense. The standard also requires an entity that is the customer to expense the capitalized implementation costs of a hosting arrangement over the term of the hosting arrangement. The new guidance requires an entity to present the expense related to the capitalized implementation costs in the same line item in the statement of income as the fees associated with the hosting element of the arrangement and classify payments for capitalized implementation costs in the statement of cash flows in the same manner as payments made for fees associated with the hosting element. The entity is also required to present the capitalized implementation costs in the statement of financial position in the same line item that a prepayment for the fees of the associated hosting arrangement would be presented. The guidance is effective for annual and interim periods beginning after December 15, 2019. The Company adopted the new guidance in the first quarter of 2020. The new guidance did not have a material impact on the Company's consolidated financial position, results of operations or cash flows. Recent Accounting Guidance Not Yet Adopted In December 2019, the FASB issued an ASU which simplifies the accounting for income taxes by removing certain exceptions to the general principles in ASC Topic 740. The ASU also clarifies and amends certain areas of ASC Topic 740 to improve consistent application of and simplify the generally accepted accounting principles within Topic 740. The guidance is effective for annual and interim periods beginning after December 15, 2020. The Company is currently evaluating the potential impact of the ASU on the Company's consolidated financial position, results of operations and cash flows.

Acquisitions (Tables)

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2020
Business Combinations [Abstract]
Schedule of Allocation of the Fair Value of Assets Acquired and Liabilities Assumed	The Company's preliminary allocation of the fair value of assets acquired and liabilities assumed as of the acquisition date of January 23, 2020 is as follows ($ in millions): Assets acquired and liabilities assumed Cash and cash equivalents $ 2,899 Premium and related receivables 3,414 Short-term investments 403 Other current assets 1,158 Long-term investments 2,699 Restricted deposits 319 Property, software and equipment 270 Intangible assets (a) 7,000 Other long-term assets 261 Total assets acquired 18,423 Medical claims liability 3,962 Accounts payable and accrued expenses 3,142 Return of premium payable 238 Unearned revenue 223 Long-term debt (b) 2,055 Deferred tax liabilities (c) 1,537 Other long-term liabilities 281 Total liabilities assumed 11,438 Total identifiable net assets 6,985 Goodwill (d) 10,620 Total assets acquired and liabilities assumed $ 17,605
Schedule of Fair Values and Weighted Average Useful Lives for Intangible Assets Acquired	The preliminary fair values and weighted average useful lives for identifiable intangible assets acquired are as follows: Fair Value Weighted Average Useful Life (in years) Purchased contract rights $ 5,200 Trade names 800 Provider contracts 700 Developed technologies 300 Total intangible assets acquired $ 7,000 13
Supplement Pro Forma Information	The following table presents supplemental pro forma information for the three months ended March 31, 2019 ($ in millions, except per share data): Three Months Ended Total revenues $ 25,169 Net earnings attributable to common stockholders $ 552 Diluted earnings per share $ 0.93

Short-term and Long-term Inve_2

Short-term and Long-term Investments, Restricted Deposits (Tables)	3 Months Ended
	Mar. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Short-term and long-term investments and restricted deposits by investment type	Short-term and long-term investments and restricted deposits by investment type consist of the following ($ in millions): March 31, 2020 December 31, 2019 Amortized Cost Gross Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Fair Value Debt securities: U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 771 $ 7 $ — $ 778 $ 211 $ 1 $ — $ 212 Corporate securities 5,036 76 (134 ) 4,978 3,629 108 (4 ) 3,733 Restricted certificates of deposit 153 — — 153 482 — — 482 Restricted cash equivalents 149 — — 149 8 — — 8 Short-term time deposits 84 — — 84 — — — — Municipal securities 2,511 77 (4 ) 2,584 2,320 69 (1 ) 2,388 Asset-backed securities 1,050 4 (36 ) 1,018 741 5 (2 ) 744 Residential mortgage-backed securities 997 32 (2 ) 1,027 464 8 (1 ) 471 Commercial mortgage-backed securities 590 10 (13 ) 587 380 9 (1 ) 388 Equity securities (1) 685 — — 685 — — — — Private equity investments 748 — — 748 664 — — 664 Life insurance contracts 130 — — 130 148 — — 148 Total $ 12,904 $ 206 $ (189 ) $ 12,921 $ 9,047 $ 200 $ (9 ) $ 9,238 (1) Investments in equity securities primarily consists of exchange traded funds in fixed income securities.
Fair value of available-for-sale investments with gross unrealized losses by investment type and length of time	The fair value of available-for-sale debt securities with gross unrealized losses by investment type and length of time that individual securities have been in a continuous unrealized loss position were as follows ($ in millions): March 31, 2020 December 31, 2019 Less Than 12 Months 12 Months or More Less Than 12 Months 12 Months or More Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value U.S. Treasury securities and obligations of U.S. government corporations and agencies $ — $ 374 $ — $ — $ — $ 11 $ — $ 31 Corporate securities (130 ) 2,461 (4 ) 16 (2 ) 192 (2 ) 48 Municipal securities (4 ) 275 — 1 (1 ) 185 — 11 Asset-backed securities (30 ) 628 (6 ) 102 (1 ) 153 (1 ) 151 Residential mortgage-backed securities (2 ) 68 — 6 — 44 (1 ) 81 Commercial mortgage-backed securities (13 ) 280 — 3 (1 ) 118 — 21 Short-term time deposits — — — 2 — — — — Total $ (179 ) $ 4,086 $ (10 ) $ 130 $ (5 ) $ 703 $ (4 ) $ 343
Contractual maturities of short-term and long-term investments and restricted deposits	The contractual maturities of short-term and long-term debt securities and restricted deposits are as follows ($ in millions): March 31, 2020 December 31, 2019 Investments Restricted Deposits Investments Restricted Deposits Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value Amortized Cost Fair Value One year or less $ 1,239 $ 1,237 $ 841 $ 842 $ 750 $ 752 $ 550 $ 550 One year through five years 3,954 3,935 169 172 3,034 3,106 106 108 Five years through ten years 2,430 2,465 — — 2,162 2,257 — — Greater than ten years 72 74 — — 48 50 — — Asset-backed securities 2,636 2,633 — — 1,585 1,603 — — Total $ 10,331 $ 10,344 $ 1,010 $ 1,014 $ 7,579 $ 7,768 $ 656 $ 658

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements by Level for Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table summarizes fair value measurements by level at March 31, 2020 , for assets and liabilities measured at fair value on a recurring basis ($ in millions): Level I Level II Level III Total Assets Cash and cash equivalents $ 9,308 $ — $ — $ 9,308 Investments: U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 114 $ — $ — $ 114 Corporate securities — 4,960 — 4,960 Municipal securities — 2,554 — 2,554 Short-term time deposits — 84 — 84 Asset-backed securities — 1,018 — 1,018 Residential mortgage-backed securities — 1,027 — 1,027 Commercial mortgage-backed securities — 587 — 587 Equity securities 683 2 — 685 Total investments $ 797 $ 10,232 $ — $ 11,029 Restricted deposits: Cash and cash equivalents $ 149 $ — $ — $ 149 Certificates of deposit — 153 — 153 Corporate securities — 18 — $ 18 Municipal securities — 30 — 30 U.S. Treasury securities and obligations of U.S. government corporations and agencies 664 — — 664 Total restricted deposits $ 813 $ 201 $ — $ 1,014 Total assets at fair value $ 10,918 $ 10,433 $ — $ 21,351 The following table summarizes fair value measurements by level at December 31, 2019 , for assets and liabilities measured at fair value on a recurring basis ($ in millions): Level I Level II Level III Total Assets Cash and cash equivalents $ 12,123 $ — $ — $ 12,123 Investments: U.S. Treasury securities and obligations of U.S. government corporations and agencies $ 73 $ — $ — $ 73 Corporate securities — 3,713 — 3,713 Municipal securities — 2,379 — 2,379 Asset-backed securities — 744 — 744 Residential mortgage-backed securities — 471 — 471 Commercial mortgage-backed securities — 388 — 388 Total investments $ 73 $ 7,695 $ — $ 7,768 Restricted deposits: Cash and cash equivalents $ 8 $ — $ — $ 8 Certificates of deposit — 482 — 482 Corporate securities — 20 — 20 Municipal securities — 9 — 9 U.S. Treasury securities and obligations of U.S. government corporations and agencies 139 — — 139 Total restricted deposits $ 147 $ 511 $ — $ 658 Other long-term assets: Interest rate swap agreements $ — $ 10 $ — $ 10 Total assets at fair value $ 12,343 $ 8,216 $ — $ 20,559 Liabilities Other long-term liabilities: Interest rate swap agreements $ — $ 11 $ — $ 11 Total liabilities at fair value $ — $ 11 $ — $ 11

Medical Claims Liability (Table

Medical Claims Liability (Tables)	3 Months Ended
	Mar. 31, 2020
Insurance [Abstract]
Schedule of change in medical claims liability	The following table summarizes the change in medical claims liability ($ in millions): Three Months Ended March 31, 2020 2019 Balance, January 1 $ 7,473 $ 6,831 Less: Reinsurance recoverable 20 27 Balance, January 1, net 7,453 6,804 Acquisitions and divestitures 3,697 6 Incurred related to: Current year 20,866 14,376 Prior years (446 ) (494 ) Total incurred 20,420 13,882 Paid related to: Current year 15,147 8,771 Prior years 5,031 4,560 Total paid 20,178 13,331 Balance at March 31, net 11,392 7,361 Plus: Reinsurance recoverable 21 20 Balance, March 31 $ 11,413 $ 7,381

Affordable Care Act (Tables)

Affordable Care Act (Tables)	3 Months Ended
	Mar. 31, 2020
Affordable Care Act [Abstract]
Schedule of net receivables (payables) related to the Affordable Care Act Programs	The Company's net receivables (payables) for each of the programs are as follows ($ in millions): March 31, 2020 December 31, 2019 Risk adjustment receivable $ 326 $ 245 Risk adjustment payable (1,569 ) (1,239 ) Minimum medical loss ratio (466 ) (367 ) Cost sharing reduction receivable 96 73 Cost sharing reduction payable (1 ) (1 )

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2020
Debt Disclosure [Abstract]
Schedule of Debt	Debt consists of the following ($ in millions): March 31, 2020 December 31, 2019 $1,000 million 4.75% Senior Notes, due May 15, 2022 $ 1,007 $ 1,004 $1,000 million 6.125% Senior Notes, due February 15, 2024 — 1,000 $2,200 million 4.75% Senior Notes, due January 15, 2025 2,236 2,228 $1,200 million 5.250% Senior Notes due April 1, 2025 1,250 — $1,800 million 5.375% Senior Notes, due June 1, 2026 1,800 1,800 $750 million 5.375% Senior Notes due August 15, 2026 800 — $2,500 million 4.25% Senior Notes due December 15, 2027 2,480 2,479 $3,500 million 4.625% Senior Notes due December 15, 2029 3,500 3,500 $2,000 million 3.375% Senior Notes due February 15, 2030 2,000 — Fair value of interest rate swap agreements — (1 ) Total senior notes 15,073 12,010 Term loan credit facility 1,450 1,450 Revolving credit agreement 588 93 Mortgage notes payable 53 54 Construction loan payable 149 140 Finance leases and other 119 122 Debt issuance costs (153 ) (143 ) Total debt 17,279 13,726 Less current portion (129 ) (88 ) Long-term debt $ 17,150 $ 13,638

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2020
Leases [Abstract]
ROU Assets and Liabilities	The following table sets forth the ROU assets and liabilities as of March 31, 2020 ($ in millions): March 31, 2020 Assets ROU assets (recorded within other long-term assets) $ 852 Liabilities Short-term (recorded within accounts payable and accrued expenses) $ 198 Long-term (recorded within other long-term liabilities) 794 Total ROU liabilities $ 992
Maturity of Operating Lease Liabilities	Lease payments over the next five years and thereafter are as follows ($ in millions): March 31, 2020 2020 $ 177 2021 223 2022 174 2023 140 2024 117 2025 82 Thereafter 258 Total lease payments 1,171 Less: imputed interest (179 ) Total ROU liabilities $ 992

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2020
Earnings Per Share [Abstract]
Calculation of Basic and Diluted Net Earnings Per Common Share	The following table sets forth the calculation of basic and diluted net earnings per common share ($ in millions, except per share data in dollars and shares in thousands): Three Months Ended March 31, 2020 2019 Earnings attributable to Centene Corporation $ 46 $ 522 Shares used in computing per share amounts: Weighted average number of common shares outstanding 544,436 412,924 Common stock equivalents (as determined by applying the treasury stock method) 7,626 6,828 Weighted average number of common shares and potential dilutive common shares outstanding 552,062 419,752 Net earnings per common share attributable to Centene Corporation: Basic earnings per common share $ 0.08 $ 1.26 Diluted earnings per common share $ 0.08 $ 1.24

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2020
Segment Reporting [Abstract]
Segment Information	Segment information for the three months ended March 31, 2020 , follows ($ in millions): Managed Care Specialty Services Eliminations Consolidated Total Total revenues from external customers $ 24,936 $ 1,089 $ — $ 26,025 Total revenues from internal customers 100 2,814 (2,914 ) — Total revenues $ 25,036 $ 3,903 $ (2,914 ) $ 26,025 Earnings from operations $ 217 $ (29 ) $ — $ 188 Segment information for the three months ended March 31, 2019 , follows ($ in millions): Managed Care Specialty Services Eliminations Consolidated Total Total revenues from external customers $ 17,687 $ 757 $ — $ 18,444 Total revenues from internal customers 35 2,449 (2,484 ) — Total revenues $ 17,722 $ 3,206 $ (2,484 ) $ 18,444 Earnings from operations $ 615 $ 70 $ — $ 685

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) $ / shares in Units, shares in Millions, $ in Millions	Jan. 23, 2020USD ($)$ / sharesshares	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)
Business Acquisition [Line Items]
Centene stock price (in usd per share) | $ / shares	$ 66.76
Acquisition related costs		$ 313
Gain on divestiture		(93)	$ 0
Centene Illinois Medicaid and Medicare Advantage Health Plans
Business Acquisition [Line Items]
Gain on divestiture	$ (93)
WellCare Health Plans, Inc.
Business Acquisition [Line Items]
Transaction value	19,555
Consideration transferred	17,605
Consideration transferred, shares valued	11,431
Cash paid	6,079
Consideration transferred related to fair value of replacement equity awards associated with pre-combination service	$ 95
Common stock cancelled and converted into right to Centene common stock	3.38
Cash paid per acquiree share, without interest (in usd per share) | $ / shares	$ 120
Shares issued (in shares) | shares	171
Pro forma revenue (unaudited)		$ 27,815	$ 25,169

Acquisitions - Schedule of Fair

Acquisitions - Schedule of Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Jan. 23, 2020	Mar. 31, 2020	Dec. 31, 2019
Assets acquired and liabilities assumed
Goodwill		$ 17,417	$ 6,863
WellCare Health Plans, Inc.
Assets acquired and liabilities assumed
Cash and cash equivalents	$ 2,899
Premium and related receivables	3,414
Short-term investments	403
Other current assets	1,158
Long-term investments	2,699
Restricted deposits	319
Property, software and equipment	270
Intangible assets	7,000
Other long-term assets	261
Total assets acquired	18,423
Medical claims liability	3,962
Accounts payable and accrued expenses	3,142
Return of premium payable	238
Unearned revenue	223
Long-term debt	2,055
Deferred tax liabilities	1,537
Other long-term liabilities	281
Total liabilities assumed	11,438
Total identifiable net assets	6,985
Goodwill	10,620
Total assets acquired and liabilities assumed	$ 17,605
Acquired intangibles, weighted average useful life years	13 years
Debt assumed, aggregate principle	$ 1,950
Debt assumed, excess of principle	105
Deferred tax assets	408
WellCare Health Plans, Inc. | Customer relationships
Assets acquired and liabilities assumed
Intangible assets	5,200
WellCare Health Plans, Inc. | Provider contracts
Assets acquired and liabilities assumed
Intangible assets	700
WellCare Health Plans, Inc. | Trade names
Assets acquired and liabilities assumed
Intangible assets	800
WellCare Health Plans, Inc. | Developed technologies
Assets acquired and liabilities assumed
Intangible assets	$ 300

Acquisitions - Supplemental Pro

Acquisitions - Supplemental Proforma Information (Details) - WellCare Health Plans, Inc. - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Business Acquisition [Line Items]
Total revenues	$ 27,815	$ 25,169
Net earnings attributable to common stockholders		$ 552
Diluted earnings per share (in usd per share)		$ 0.93

Short-term and Long-term Inve_3

Short-term and Long-term Investments, Restricted Deposits - By Investment Type (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Debt Securities
Gross Unrealized Gains	$ 206	$ 200
Gross Unrealized Losses	(189)	(9)
Equity securities	685	0
Private equity investments	748	664
Life insurance contracts	130	148
Total, Amortized Cost	12,904	9,047
Total, Fair Value	12,921	9,238
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Debt Securities
Amortized Cost	771	211
Gross Unrealized Gains	7	1
Gross Unrealized Losses	0	0
Fair Value	778	212
Corporate securities
Debt Securities
Amortized Cost	5,036	3,629
Gross Unrealized Gains	76	108
Gross Unrealized Losses	(134)	(4)
Fair Value	4,978	3,733
Restricted certificates of deposit
Debt Securities
Amortized Cost	153	482
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	153	482
Restricted cash equivalents
Debt Securities
Amortized Cost	149	8
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	149	8
Short-term time deposits
Debt Securities
Amortized Cost	84	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	84	0
Municipal securities
Debt Securities
Amortized Cost	2,511	2,320
Gross Unrealized Gains	77	69
Gross Unrealized Losses	(4)	(1)
Fair Value	2,584	2,388
Asset-backed securities
Debt Securities
Amortized Cost	1,050	741
Gross Unrealized Gains	4	5
Gross Unrealized Losses	(36)	(2)
Fair Value	1,018	744
Residential mortgage-backed securities
Debt Securities
Amortized Cost	997	464
Gross Unrealized Gains	32	8
Gross Unrealized Losses	(2)	(1)
Fair Value	1,027	471
Commercial mortgage-backed securities
Debt Securities
Amortized Cost	590	380
Gross Unrealized Gains	10	9
Gross Unrealized Losses	(13)	(1)
Fair Value	$ 587	$ 388

Short-term and Long-term Inve_4

Short-term and Long-term Investments, Restricted Deposits - Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020USD ($)position	Dec. 31, 2019
Schedule Of Investments And Restricted Deposits By Type [Line Items]
Accrued interest income | $	$ 78
Positions from which gross unrealized losses were generated	2,636
Total unrealized investment positions	5,998
Commercial mortgage-backed securities
Schedule Of Investments And Restricted Deposits By Type [Line Items]
Investments recorded at fair value that carry rating of AA Plus, weighted average (in years)		4 years
Rated Securities | External Credit Rating, Investment Grade
Schedule Of Investments And Restricted Deposits By Type [Line Items]
Percentage of investments in rated securities carry an investment grade rating by nationally recognized statistical rating organizations	97.00%

Short-term and Long-term Inve_5

Short-term and Long-term Investments, Restricted Deposits - Fair Value of Available-For-Sale Investments with Gross Unrealized Losses by Investment Type and Length of Time (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Unrealized Losses
Less Than 12 Months	$ (179)	$ (5)
12 Months or More	(10)	(4)
Fair Value
Fair Value, Less Than 12 Months	4,086	703
Fair Value, 12 Months or More	130	343
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Unrealized Losses
Less Than 12 Months	0	0
12 Months or More	0	0
Fair Value
Fair Value, Less Than 12 Months	374	11
Fair Value, 12 Months or More	0	31
Corporate securities
Unrealized Losses
Less Than 12 Months	(130)	(2)
12 Months or More	(4)	(2)
Fair Value
Fair Value, Less Than 12 Months	2,461	192
Fair Value, 12 Months or More	16	48
Municipal securities
Unrealized Losses
Less Than 12 Months	(4)	(1)
12 Months or More	0	0
Fair Value
Fair Value, Less Than 12 Months	275	185
Fair Value, 12 Months or More	1	11
Asset-backed securities
Unrealized Losses
Less Than 12 Months	(30)	(1)
12 Months or More	(6)	(1)
Fair Value
Fair Value, Less Than 12 Months	628	153
Fair Value, 12 Months or More	102	151
Residential mortgage-backed securities
Unrealized Losses
Less Than 12 Months	(2)	0
12 Months or More	0	(1)
Fair Value
Fair Value, Less Than 12 Months	68	44
Fair Value, 12 Months or More	6	81
Commercial mortgage-backed securities
Unrealized Losses
Less Than 12 Months	(13)	(1)
12 Months or More	0	0
Fair Value
Fair Value, Less Than 12 Months	280	118
Fair Value, 12 Months or More	3	21
Short-term time deposits
Unrealized Losses
Less Than 12 Months	0	0
12 Months or More	0	0
Fair Value
Fair Value, Less Than 12 Months	0	0
Fair Value, 12 Months or More	$ 2	$ 0

Short-term and Long-term Inve_6

Short-term and Long-term Investments, Restricted Deposits - Contractual Maturities of Short-Term and Long-Term Investments and Restricted Deposits (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Investments
Amortized Cost
One year or less	$ 1,239	$ 750
One year through five years	3,954	3,034
Five years through ten years	2,430	2,162
Greater than ten years	72	48
Asset-backed securities	2,636	1,585
Amortized Cost	10,331	7,579
Fair Value
One year or less	1,237	752
One year through five years	3,935	3,106
Five years through ten years	2,465	2,257
Greater than ten years	74	50
Asset-backed securities	2,633	1,603
Fair Value	10,344	7,768
Restricted Deposits
Amortized Cost
One year or less	841	550
One year through five years	169	106
Five years through ten years	0	0
Greater than ten years	0	0
Asset-backed securities	0	0
Amortized Cost	1,010	656
Fair Value
One year or less	842	550
One year through five years	172	108
Five years through ten years	0	0
Greater than ten years	0	0
Asset-backed securities	0	0
Fair Value	$ 1,014	$ 658

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Measurements by Level for Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Assets
Cash and cash equivalents	$ 9,308	$ 12,123
Investments:
Equity securities	685	0
Other long-term assets:
Total assets at fair value	21,351	20,559
Other long-term liabilities:
Total liabilities at fair value		11
U.S. Treasury securities and obligations of U.S. government corporations and agencies
Investments:
Fair Value	778	212
Corporate securities
Investments:
Fair Value	4,978	3,733
Municipal securities
Investments:
Fair Value	2,584	2,388
Short-term time deposits
Investments:
Fair Value	84	0
Asset-backed securities
Investments:
Fair Value	1,018	744
Residential mortgage-backed securities
Investments:
Fair Value	1,027	471
Commercial mortgage-backed securities
Investments:
Fair Value	587	388
Interest rate swap agreements
Other long-term liabilities:
Interest rate swap agreements		11
Available-for-sale Securities
Investments:
Fair Value	11,029	7,768
Available-for-sale Securities | U.S. Treasury securities and obligations of U.S. government corporations and agencies
Investments:
Fair Value	114	73
Available-for-sale Securities | Corporate securities
Investments:
Fair Value	4,960	3,713
Available-for-sale Securities | Municipal securities
Investments:
Fair Value	2,554	2,379
Available-for-sale Securities | Short-term time deposits
Investments:
Fair Value	84
Available-for-sale Securities | Asset-backed securities
Investments:
Fair Value	1,018	744
Available-for-sale Securities | Residential mortgage-backed securities
Investments:
Fair Value	1,027	471
Available-for-sale Securities | Commercial mortgage-backed securities
Investments:
Fair Value	587	388
Restricted Deposits
Investments:
Fair Value	1,014	658
Restricted Deposits | U.S. Treasury securities and obligations of U.S. government corporations and agencies
Investments:
Fair Value	664	139
Restricted Deposits | Corporate securities
Investments:
Fair Value	18	20
Restricted Deposits | Municipal securities
Investments:
Fair Value	30	9
Restricted Deposits | Cash and cash equivalents
Investments:
Fair Value	149	8
Restricted Deposits | Certificates of deposit
Investments:
Fair Value	153	482
Other long-term assets | Interest rate swap agreements
Other long-term assets:
Derivative asset		10
Level I
Assets
Cash and cash equivalents	9,308	12,123
Investments:
Equity securities	683
Other long-term assets:
Total assets at fair value	10,918	12,343
Other long-term liabilities:
Total liabilities at fair value		0
Level I | Interest rate swap agreements
Other long-term liabilities:
Interest rate swap agreements		0
Level I | Available-for-sale Securities
Investments:
Fair Value	797	73
Level I | Available-for-sale Securities | U.S. Treasury securities and obligations of U.S. government corporations and agencies
Investments:
Fair Value	114	73
Level I | Available-for-sale Securities | Corporate securities
Investments:
Fair Value	0	0
Level I | Available-for-sale Securities | Municipal securities
Investments:
Fair Value	0	0
Level I | Available-for-sale Securities | Short-term time deposits
Investments:
Fair Value	0
Level I | Available-for-sale Securities | Asset-backed securities
Investments:
Fair Value	0	0
Level I | Available-for-sale Securities | Residential mortgage-backed securities
Investments:
Fair Value	0	0
Level I | Available-for-sale Securities | Commercial mortgage-backed securities
Investments:
Fair Value	0	0
Level I | Restricted Deposits
Investments:
Fair Value	813	147
Level I | Restricted Deposits | U.S. Treasury securities and obligations of U.S. government corporations and agencies
Investments:
Fair Value	664	139
Level I | Restricted Deposits | Corporate securities
Investments:
Fair Value	0	0
Level I | Restricted Deposits | Municipal securities
Investments:
Fair Value	0	0
Level I | Restricted Deposits | Cash and cash equivalents
Investments:
Fair Value	149	8
Level I | Restricted Deposits | Certificates of deposit
Investments:
Fair Value	0	0
Level I | Other long-term assets | Interest rate swap agreements
Other long-term assets:
Derivative asset		0
Level II
Assets
Cash and cash equivalents	0	0
Investments:
Equity securities	2
Other long-term assets:
Total assets at fair value	10,433	8,216
Other long-term liabilities:
Total liabilities at fair value		11
Level II | Interest rate swap agreements
Other long-term liabilities:
Interest rate swap agreements		11
Level II | Available-for-sale Securities
Investments:
Fair Value	10,232	7,695
Level II | Available-for-sale Securities | U.S. Treasury securities and obligations of U.S. government corporations and agencies
Investments:
Fair Value	0	0
Level II | Available-for-sale Securities | Corporate securities
Investments:
Fair Value	4,960	3,713
Level II | Available-for-sale Securities | Municipal securities
Investments:
Fair Value	2,554	2,379
Level II | Available-for-sale Securities | Short-term time deposits
Investments:
Fair Value	84
Level II | Available-for-sale Securities | Asset-backed securities
Investments:
Fair Value	1,018	744
Level II | Available-for-sale Securities | Residential mortgage-backed securities
Investments:
Fair Value	1,027	471
Level II | Available-for-sale Securities | Commercial mortgage-backed securities
Investments:
Fair Value	587	388
Level II | Restricted Deposits
Investments:
Fair Value	201	511
Level II | Restricted Deposits | U.S. Treasury securities and obligations of U.S. government corporations and agencies
Investments:
Fair Value	0	0
Level II | Restricted Deposits | Corporate securities
Investments:
Fair Value	18	20
Level II | Restricted Deposits | Municipal securities
Investments:
Fair Value	30	9
Level II | Restricted Deposits | Cash and cash equivalents
Investments:
Fair Value	0	0
Level II | Restricted Deposits | Certificates of deposit
Investments:
Fair Value	153	482
Level II | Other long-term assets | Interest rate swap agreements
Other long-term assets:
Derivative asset		10
Level III
Assets
Cash and cash equivalents	0	0
Investments:
Equity securities	0
Other long-term assets:
Total assets at fair value	0	0
Other long-term liabilities:
Total liabilities at fair value		0
Level III | Interest rate swap agreements
Other long-term liabilities:
Interest rate swap agreements		0
Level III | Available-for-sale Securities
Investments:
Fair Value	0	0
Level III | Available-for-sale Securities | U.S. Treasury securities and obligations of U.S. government corporations and agencies
Investments:
Fair Value	0	0
Level III | Available-for-sale Securities | Corporate securities
Investments:
Fair Value	0	0
Level III | Available-for-sale Securities | Municipal securities
Investments:
Fair Value	0	0
Level III | Available-for-sale Securities | Short-term time deposits
Investments:
Fair Value	0
Level III | Available-for-sale Securities | Asset-backed securities
Investments:
Fair Value	0	0
Level III | Available-for-sale Securities | Residential mortgage-backed securities
Investments:
Fair Value	0	0
Level III | Available-for-sale Securities | Commercial mortgage-backed securities
Investments:
Fair Value	0	0
Level III | Restricted Deposits
Investments:
Fair Value	0	0
Level III | Restricted Deposits | U.S. Treasury securities and obligations of U.S. government corporations and agencies
Investments:
Fair Value	0	0
Level III | Restricted Deposits | Corporate securities
Investments:
Fair Value	0	0
Level III | Restricted Deposits | Municipal securities
Investments:
Fair Value	0	0
Level III | Restricted Deposits | Cash and cash equivalents
Investments:
Fair Value	0	0
Level III | Restricted Deposits | Certificates of deposit
Investments:
Fair Value	$ 0	0
Level III | Other long-term assets | Interest rate swap agreements
Other long-term assets:
Derivative asset		$ 0

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Aggregate carrying amount of life insurance contracts and equity investments, fair value	$ 878	$ 812

Medical Claims Liability - Sche

Medical Claims Liability - Schedule of Change in Medical Claims Liability (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance, January 1	$ 7,473	$ 6,831
Less: Reinsurance recoverable	20	27
Balance, January 1, net	7,453	6,804
Acquisitions and divestitures	3,697	6
Incurred related to:
Current year	20,866	14,376
Prior years	(446)	(494)
Total incurred	20,420	13,882
Paid related to:
Current year	15,147	8,771
Prior years	5,031	4,560
Total paid	20,178	13,331
Balance at March 31, net	11,392	7,361
Plus: Reinsurance recoverable	21	20
Balance, March 31	$ 11,413	$ 7,381

Medical Claims Liability - Narr

Medical Claims Liability - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Insurance [Abstract]
Amounts recorded as an adjustment to premium revenues related to minimum HBR and return of premium programs	$ (31)	$ 8
Short-duration insurance contracts, Incurred but not reported and expected development on reported claims	$ 7,527

Affordable Care Act - Net Recei

Affordable Care Act - Net Receivables (Payables) for Each of the Ongoing Programs (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Affordable Care Act [Abstract]
Risk adjustment receivable	$ 326	$ 245
Risk adjustment payable	(1,569)	(1,239)
Minimum medical loss ratio	(466)	(367)
Cost sharing reduction receivable	96	73
Cost sharing reduction payable	$ (1)	$ (1)

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($)	Mar. 31, 2020	Feb. 29, 2020	Jan. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Fair value of interest rate swap agreements	$ 0			$ (1,000,000)
Total senior notes	15,073,000,000			12,010,000,000
Mortgage notes payable	53,000,000			54,000,000
Construction loan payable	149,000,000			140,000,000
Finance leases and other	119,000,000			122,000,000
Debt issuance costs	(153,000,000)			(143,000,000)
Total debt	17,279,000,000			13,726,000,000
Less current portion	(129,000,000)			(88,000,000)
Long-term debt	17,150,000,000			13,638,000,000
Revolving credit agreement
Debt Instrument [Line Items]
Revolving credit agreement	588,000,000			93,000,000
Senior Notes
Debt Instrument [Line Items]
Debt, face amount	2,100,000,000
Term loan credit facility
Debt Instrument [Line Items]
Revolving credit agreement	1,450,000,000			1,450,000,000
$1,000 million 4.75% Senior Notes, due May 15, 2022 | Senior Notes
Debt Instrument [Line Items]
Debt, face amount	$ 1,000,000,000
Interest rate	4.75%		4.75%
Senior notes	$ 1,007,000,000			1,004,000,000
$1,000 million 6.125% Senior Notes, due February 15, 2024 | Senior Notes
Debt Instrument [Line Items]
Debt, face amount		$ 1,000,000,000
Interest rate		6.125%
Senior notes	0			1,000,000,000
$2,200 million 4.75% Senior Notes, due January 15, 2025 | Senior Notes
Debt Instrument [Line Items]
Debt, face amount	$ 2,200,000,000
Interest rate	4.75%
Senior notes	$ 2,236,000,000			2,228,000,000
$1,200 million 5.250% Senior Notes due April 1, 2025 | Senior Notes
Debt Instrument [Line Items]
Senior notes	1,250,000,000			0
$1,800 million 5.375% Senior Notes, due June 1, 2026 | Senior Notes
Debt Instrument [Line Items]
Debt, face amount	$ 1,800,000,000
Interest rate	5.375%
Senior notes	$ 1,800,000,000			1,800,000,000
$2,500 million 4.25% Senior Notes due December 15, 2027 | Senior Notes
Debt Instrument [Line Items]
Debt, face amount	$ 2,500,000
Interest rate	4.25%
Senior notes	$ 2,480,000,000			2,479,000,000
$3,500 million 4.625% Senior Notes due December 15, 2029 | Senior Notes
Debt Instrument [Line Items]
Debt, face amount	$ 3,500,000
Interest rate	4.625%
Senior notes	$ 3,500,000,000			3,500,000,000
$2,000 million 3.375% Senior Notes due February 15, 2030 | Senior Notes
Debt Instrument [Line Items]
Debt, face amount	$ 2,000,000	$ 2,000,000,000
Interest rate	3.375%	3.375%
Senior notes	$ 2,000,000,000			0
WellCare Health Plans, Inc. | $1,200 million 5.250% Senior Notes due April 1, 2025 | Senior Notes
Debt Instrument [Line Items]
Debt, face amount			$ 1,200,000,000
Interest rate			5.25%
WellCare Health Plans, Inc. | $750 million 5.375% Senior Notes due August 15, 2026 | Senior Notes
Debt Instrument [Line Items]
Debt, face amount	$ 750,000		$ 750,000,000
Interest rate	5.375%		5.375%
Senior notes	$ 800,000,000			$ 0

Debt - Narrative (Details)

Debt - Narrative (Details)	1 Months Ended	3 Months Ended
	Feb. 29, 2020USD ($)	Mar. 31, 2020USD ($)derivative	Mar. 31, 2019USD ($)	Jan. 31, 2020USD ($)	Jan. 23, 2020USD ($)
Debt Instrument [Line Items]
Loss on extinguishment of debt	$ 44,000,000	$ 44,000,000	$ 0
Number of Interest rate swap contracts terminated | derivative		3
Proceeds from termination of interest rate swaps		$ 9,000,000
WellCare Health Plans, Inc.
Debt Instrument [Line Items]
Acquisition of WellCare Notes					$ 2,055,000,000
Interest Rate Swap
Debt Instrument [Line Items]
Derivative notional amount	1,000,000,000	2,100,000,000
Senior Notes
Debt Instrument [Line Items]
Debt, face amount		2,100,000,000
Senior Notes | 3.375% Senior Notes Due 2030
Debt Instrument [Line Items]
Debt, face amount	$ 2,000,000,000	$ 2,000,000
Interest rate	3.375%	3.375%
Senior Notes | $1,000 million 6.125% Senior Notes, due February 15, 2024
Debt Instrument [Line Items]
Debt, face amount	$ 1,000,000,000
Interest rate	6.125%
Senior Notes | $1,000 million 4.75% Senior Notes, due May 15, 2022
Debt Instrument [Line Items]
Debt, face amount		$ 1,000,000,000
Interest rate		4.75%		4.75%
Debt redemption amount				$ 1,000,000,000
Senior Notes | $1,200 Million Senior Notes Due April 2025 | WellCare Health Plans, Inc.
Debt Instrument [Line Items]
Debt, face amount				$ 1,200,000,000
Interest rate				5.25%
Senior Notes | $750 million 5.375% Senior Notes due August 15, 2026 | WellCare Health Plans, Inc.
Debt Instrument [Line Items]
Debt, face amount		$ 750,000		$ 750,000,000
Interest rate		5.375%		5.375%
Senior Notes | $1,146 Million 5.25% Senior Notes Due 2025 | WellCare Health Plans, Inc.
Debt Instrument [Line Items]
Debt, face amount				$ 1,146,000,000
Interest rate				5.25%
Senior Notes | 5.375% Senior Notes Due 2026 | WellCare Health Plans, Inc.
Debt Instrument [Line Items]
Debt, face amount				$ 747,000,000
Interest rate				5.375%
Senior Notes | $2,200 million 4.75% Senior Notes, due January 15, 2025
Debt Instrument [Line Items]
Debt, face amount		$ 2,200,000,000
Interest rate		4.75%

Leases - Additional (Details)

Leases - Additional (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020USD ($)lease	Jan. 23, 2020USD ($)
Lessee, Lease, Description [Line Items]
Lease terms	12 months
Operating lease expense	$ 62
ROU assets acquired	852
ROU liability acquired	992
Lease liabilities reduced by cash paid	63
Operating leases not yet commenced	$ 421
Operating leases not yet commenced, number of significant leases executed | lease	4
Weighted average remaining lease term	6 years 9 months 18 days
Weighted-average discount rate for operating leases	4.70%
Minimum
Lessee, Lease, Description [Line Items]
Lease terms	2 years
Maximum
Lessee, Lease, Description [Line Items]
Lease terms	16 years
WellCare Health Plans, Inc.
Lessee, Lease, Description [Line Items]
ROU assets acquired		$ 240
ROU liability acquired		$ 260

Leases - ROU Assets and Liabili

Leases - ROU Assets and Liabilities (Details) $ in Millions	Mar. 31, 2020USD ($)
Assets
ROU assets (recorded within other long-term assets)	$ 852
Liabilities
Short-term (recorded within accounts payable and accrued expenses)	198
Long-term (recorded within other long-term liabilities)	794
Total ROU liabilities	$ 992

Leases - Operating Lease Paymen

Leases - Operating Lease Payments Over Next Five Years (Details) $ in Millions	Mar. 31, 2020USD ($)
Leases [Abstract]
2020	$ 177
2021	223
2022	174
2023	140
2024	117
2025	82
Thereafter	258
Total lease payments	1,171
Less: imputed interest	(179)
Total ROU liabilities	$ 992

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) shares in Thousands, $ in Millions	Jan. 23, 2020	Mar. 31, 2020	Mar. 31, 2019
Business Acquisition [Line Items]
Common stock repurchases		$ 558	$ 35
Remaining number of shares available under the program (in shares)		5,488
WellCare Health Plans, Inc.
Business Acquisition [Line Items]
Shares issued (in shares)	171,000
Consideration transferred, shares valued	$ 11,431
Cash paid	6,079
Consideration transferred related to fair value of replacement equity awards associated with pre-combination service	$ 95
Stock Repurchase Program
Business Acquisition [Line Items]
Common stock repurchases (in shares)		8,672
Common stock repurchases		$ 500

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings attributable to Centene Corporation
Earnings attributable to Centene Corporation	$ 46	$ 522
Shares used in computing per share amounts:
Weighted average number of common shares outstanding (in shares)	544,436	412,924
Common stock equivalents (as determined by applying the treasury stock method) (in shares)	7,626	6,828
Weighted average number of common shares and potential dilutive common shares outstanding (in shares)	552,062	419,752
Net earnings per common share attributable to Centene Corporation:
Basic earnings per common share (in dollars per share)	$ 0.08	$ 1.26
Diluted earnings per common share (in dollars per share)	$ 0.08	$ 1.24
Anti-dilutive restricted stock and restricted stock units excluded from the calculation of diluted earnings per common share (in shares)	400	1,400

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2020USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2019segment
Segment Reporting [Abstract]
Number of operating segments | segment			2
Segment Reporting Information [Line Items]
Total revenues	$ 26,025	$ 18,444
Earnings from operations	188	685
Eliminations
Segment Reporting Information [Line Items]
Total revenues	(2,914)	(2,484)
Earnings from operations	0
Managed Care
Segment Reporting Information [Line Items]
Total revenues	25,036	17,722
Earnings from operations	217	615
Managed Care | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	24,936	17,687
Managed Care | Eliminations
Segment Reporting Information [Line Items]
Total revenues	100	35
Specialty Services
Segment Reporting Information [Line Items]
Total revenues	3,903	3,206
Earnings from operations	(29)	70
Specialty Services | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	1,089	757
Specialty Services | Eliminations
Segment Reporting Information [Line Items]
Total revenues	$ 2,814	$ 2,449