WellCare Health Plans 10-Q 30 Oct 19 2019 Q3 Quarterly report Financial data

Cover page

Cover page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 28, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	001-32209
Entity Registrant Name	WELLCARE HEALTH PLANS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-0937650
Entity Address, Address Line One	8735 Henderson Road, Renaissance One
Entity Address, City or Town	Tampa
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33634
City Area Code	813
Local Phone Number	290-6200
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	WCG
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		50,327,612
Entity Central Index Key	0001279363
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues:
Premium	$ 6,965.6	$ 4,988.8	$ 20,417.2	$ 14,227.7
Products and services	132.1	34.6	374.6	34.6
Investment and other income	42.5	34.7	120.7	81
Total revenues	7,140.2	5,058.1	20,912.5	14,343.3
Expenses:
Medical benefits	6,025.7	4,195	17,884.5	12,023
Costs of products and services	128.9	33.5	363.9	33.5
Selling, general and administrative	567.4	433.2	1,558	1,167
ACA industry fee	0	86.5	0	247
Medicaid premium taxes	35.6	31.5	99	94.2
Depreciation and amortization	59.9	46.2	197.6	117.1
Interest	29.4	23.6	90	57.8
Total expenses	6,846.9	4,849.5	20,193	13,739.6
Income before income taxes and equity in losses of unconsolidated subsidiaries	293.3	208.6	719.5	603.7
Equity in earnings (losses) of unconsolidated subsidiaries	20.4	6.6	22.9	(0.1)
Income before income taxes	313.7	215.2	742.4	603.6
Income tax expense	72.7	84.6	167.2	219.7
Net income	241	130.6	575.2	383.9
Other comprehensive income (loss):
Change in net unrealized gains and losses on available-for-sale securities, before tax	(3.5)	(1.1)	29.2	(11.4)
Income tax expense (benefit) related to other comprehensive income	(0.9)	(0.3)	7.3	(2.7)
Other comprehensive income (loss), net of tax	(2.6)	(0.8)	21.9	(8.7)
Comprehensive income	$ 238.4	$ 129.8	$ 597.1	$ 375.2
Earnings per common share:
Basic (in USD per share)	$ 4.79	$ 2.74	$ 11.45	$ 8.40
Diluted (in USD per share)	$ 4.74	$ 2.70	$ 11.32	$ 8.29
Weighted average common shares outstanding:
Basic (in shares)	50,313,901	47,712,712	50,240,480	45,692,804
Diluted (in shares)	50,846,402	48,384,427	50,833,504	46,287,616

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents	$ 2,567.1	$ 3,653.9
Short-term investments	1,082	830.1
Premiums receivable, net	1,447.5	1,223.4
Pharmacy rebates receivable, net	434.7	460.6
Funds receivable for the benefit of members	297.8	187.3
Prepaid expenses and other current assets, net	1,571.4	477.1
Total current assets	7,400.5	6,832.4
Property, equipment and capitalized software, net	477.3	428.2
Goodwill	2,265.2	2,227.7
Other intangible assets, net	856.9	996.2
Long-term investments	2,060.3	813.2
Restricted cash, cash equivalents and investments	317.9	234.7
Other assets	266.3	18.7
Assets of discontinued operations	217.3	213.6
Total Assets	13,861.7	11,764.7
Current Liabilities:
Medical benefits payable	3,363.9	2,897.4
Unearned premiums	48.7	1.4
Accounts payable and accrued expenses	1,923.4	964.6
Funds payable for the benefit of members	800	693.3
Other payables to government partners	268	458.9
Total current liabilities	6,404	5,015.6
Deferred income tax liability, net	105.8	134.2
Long-term debt, net	2,029.1	2,126.4
Other liabilities	249.1	34.9
Liabilities of discontinued operations	217.3	213.6
Total Liabilities	9,005.3	7,524.7
Commitments and contingencies (see Note 14)
Stockholders' Equity:
Preferred stock, $0.01 par value (20,000,000 authorized, no shares issued or outstanding)	0	0
Common stock, $0.01 par value (100,000,000 authorized, 50,316,099 and 49,993,219 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively)	0.5	0.5
Paid-in capital	2,000.4	1,981.1
Retained earnings	2,842.5	2,267.3
Accumulated other comprehensive income (loss)	13	(8.9)
Total Stockholders' Equity	4,856.4	4,240
Total Liabilities and Stockholders' Equity	$ 13,861.7	$ 11,764.7

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
Stockholders' Equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	20,000,000	20,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	100,000,000	100,000,000
Common stock, issued (in shares)	50,316,099	49,993,219
Common stock, outstanding (in shares)	50,316,099	49,993,219

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2017		44,522,988
Beginning balance at Dec. 31, 2017	$ 2,416.7	$ 0.4	$ 591.5	$ 1,827.5	$ (2.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of issuance costs (in shares)		5,207,547
Issuance of common stock, net of issuance costs	1,342.3	$ 0.1	1,342.2
Common stock issued for vested equity-compensation awards (in shares)		356,491
Repurchase and retirement of shares to satisfy tax withholding requirements (in shares)		(107,360)
Repurchase and retirement of shares to satisfy tax withholding requirements	(23.3)		(23.3)
Stock-based compensation expense, net of forfeitures	51.5		51.5
Comprehensive income	375.2			383.9	(8.7)
Ending balance (in shares) at Sep. 30, 2018		49,979,666
Ending balance at Sep. 30, 2018	4,162.4	$ 0.5	1,961.9	2,211.4	(11.4)
Beginning balance (in shares) at Jun. 30, 2018		44,767,277
Beginning balance at Jun. 30, 2018	2,671.9	$ 0.4	601.3	2,080.8	(10.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of issuance costs (in shares)		5,207,547
Issuance of common stock, net of issuance costs	1,342.3	$ 0.1	1,342.2
Common stock issued for vested equity-compensation awards (in shares)		7,266
Repurchase and retirement of shares to satisfy tax withholding requirements (in shares)		(2,424)
Repurchase and retirement of shares to satisfy tax withholding requirements	(3)		(3)
Stock-based compensation expense, net of forfeitures	21.4		21.4
Comprehensive income	129.8			130.6	(0.8)
Ending balance (in shares) at Sep. 30, 2018		49,979,666
Ending balance at Sep. 30, 2018	$ 4,162.4	$ 0.5	1,961.9	2,211.4	(11.4)
Beginning balance (in shares) at Dec. 31, 2018	49,993,219	49,993,219
Beginning balance at Dec. 31, 2018	$ 4,240	$ 0.5	1,981.1	2,267.3	(8.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued for vested equity-compensation awards (in shares)		468,246
Common stock issued for vested equity-compensation awards	0
Repurchase and retirement of shares to satisfy tax withholding requirements (in shares)		(145,366)
Repurchase and retirement of shares to satisfy tax withholding requirements	(39.6)		(39.6)
Stock-based compensation expense, net of forfeitures	58.9		58.9
Comprehensive income	$ 597.1			575.2	21.9
Ending balance (in shares) at Sep. 30, 2019	50,316,099	50,316,099
Ending balance at Sep. 30, 2019	$ 4,856.4	$ 0.5	2,000.4	2,842.5	13
Beginning balance (in shares) at Jun. 30, 2019		50,311,933
Beginning balance at Jun. 30, 2019	4,603.3	$ 0.5	1,985.7	2,601.5	15.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued for vested equity-compensation awards (in shares)		6,163
Common stock issued for vested equity-compensation awards	0
Repurchase and retirement of shares to satisfy tax withholding requirements (in shares)		(1,997)
Repurchase and retirement of shares to satisfy tax withholding requirements	(2.4)		(2.4)
Stock-based compensation expense, net of forfeitures	17.1		17.1
Comprehensive income	$ 238.4			241	(2.6)
Ending balance (in shares) at Sep. 30, 2019	50,316,099	50,316,099
Ending balance at Sep. 30, 2019	$ 4,856.4	$ 0.5	$ 2,000.4	$ 2,842.5	$ 13

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net income	$ 575.2	$ 383.9
Adjustments to reconcile net income to cash flows from operating activities:
Depreciation and amortization	197.6	117.1
Stock-based compensation expense	58.9	51.5
Deferred taxes, net	(25)	(9.8)
Other, net	11.1	13.1
Changes in operating accounts, net of effects from acquisitions:
Premiums receivable, net	(232.3)	(144.1)
Pharmacy rebates receivable, net	25.9	(138.7)
Medical benefits payable	466.5	227.1
Unearned premiums	47.3	(74.7)
Other receivables/payables to government partners	(276.2)	64.8
Prepaid and other current assets	(145.5)	(190.3)
Accrued liabilities and other, net	204.1	(101.9)
Net cash provided by operating activities	907.6	198
Cash flows from investing activities:
Purchases of investments	(4,949.8)	(1,322.6)
Proceeds from sales and maturities of investments	3,287.4	822.8
Acquisitions and acquisition-related settlements	(8.6)	(2,035.7)
Additions to property, equipment and capitalized software, net	(157.7)	(87.5)
Net cash used in investing activities	(1,828.7)	(2,623)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance fees paid	0	1,342.3
Proceeds from issuance of debt, net of financing costs paid	0	739
Borrowings on Revolving Credit Facility, net of financing costs paid	140	221.3
Repayments of Long-term Debt	(240)	(25)
Repurchase and retirement of shares to satisfy employee tax withholding requirements	(39.6)	(23.3)
Funds received for the benefit of members, net	25.9	250.8
Other, net	11.6	29.5
Net cash (used in) provided by financing activities	(102.1)	2,534.6
(Decrease) increase in cash, cash equivalents and restricted cash and cash equivalents	(1,023.2)	109.6
Balance at beginning of period	3,716.6	4,263
Balance at end of period	2,693.4	4,372.6
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for taxes, net of refunds	101.4	174.6
Cash paid for interest	112.5	65.5
SUPPLEMENTAL DISCLOSURES OF NON-CASH TRANSACTIONS:
Non-cash additions to property, equipment, and capitalized software	$ 4	$ 3.7

ORGANIZATION, BASIS OF PRESENTA

ORGANIZATION, BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION, BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES	ORGANIZATION, BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES WellCare Health Plans, Inc. (the "Company," "we," "us," or "our") focuses primarily on providing government-sponsored managed care services to families, children, seniors and individuals with complex medical needs primarily through Medicaid, Medicare Advantage ("MA") and Medicare Prescription Drug Plans ("PDP"), as well as individuals in the Health Insurance Marketplace. As of September 30, 2019 , we served approximately 6.4 million members nationwide. As of September 30, 2019 , we operated Medicaid health plans, including states where we receive Medicaid premium revenues associated with dually eligible special needs plans, in Arizona, Florida, Georgia, Hawaii, Illinois, Kentucky, Michigan, Missouri, Nebraska, New Jersey, New York, South Carolina and Texas. In addition, as of September 30, 2019 , we also operated MA coordinated care plans ("CCPs") in Alabama, Arizona, Arkansas, California, Connecticut, Florida, Georgia, Hawaii, Illinois, Indiana, Kentucky, Louisiana, Maine, Michigan, Mississippi, New Jersey, New York, North Carolina, Ohio, South Carolina, Tennessee and Texas. We also offered stand-alone Medicare PDPs nationwide. In September 2018, we completed the acquisition of Meridian Health Plan of Michigan, Inc., Meridian Health Plan of Illinois, Inc., and MeridianRx, LLC, a pharmacy benefit manager ("PBM") (collectively, "Meridian"). As a result of the acquisition, we expanded our Medicaid portfolio through the addition of Michigan; expanded our Medicaid presence in Illinois; and acquired an integrated PBM platform. Meridian also serves MA members in Illinois, Indiana, Michigan, and Ohio, as well as Health Insurance Marketplace members in Michigan. Basis of Presentation The accompanying unaudited condensed consolidated balance sheets and statements of comprehensive income, changes in stockholders' equity, and cash flows include our accounts and the accounts of our subsidiaries over which we have control or are the primary beneficiary. We eliminated all intercompany accounts and transactions. The accompanying unaudited condensed consolidated interim financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP"). Accordingly, certain financial information and footnote disclosures normally included in financial statements prepared in accordance with GAAP, but that are not required for interim reporting purposes, have been condensed or omitted. The accompanying unaudited condensed consolidated interim financial statements should be read in conjunction with the consolidated financial statements and notes thereto, for the fiscal year ended December 31, 2018 , included in our Annual Report on Form 10-K ("2018 Form 10-K"), which was filed with the U.S. Securities and Exchange Commission ("SEC") in February 2019. Results for the interim periods presented are not necessarily indicative of results that may be expected for the entire year or any other interim period. In the opinion of management, the unaudited condensed consolidated interim financial statements reflect all normal recurring adjustments that we consider necessary for the fair presentation of our financial position, results of operations and cash flows for the interim periods presented. In accordance with GAAP, we make certain estimates and assumptions that affect the amounts reported in the condensed consolidated interim financial statements and accompanying notes. We base these estimates, including assumptions as to the annualized tax rate, on our knowledge of current events and anticipated future events and evaluate and update our assumptions and estimates on an ongoing basis; however, actual results may differ from our estimates. We evaluated all material events subsequent to the date of these unaudited condensed consolidated interim financial statements. Certain reclassifications were made to 2018 financial information to conform to the 2019 presentation. Pharmacy Benefit Manager The external revenues and costs for our PBM business are reported within "Products and Services" and "Cost of Products and Services", respectively, on the condensed consolidated statements of comprehensive income. Products and services revenues from our PBM consist of the prescription price (ingredient cost plus dispensing fee) negotiated with the retail pharmacies with which we have contracted, plus any associated administrative fees. This revenue is recognized when the claim is processed. We have the contractual obligation to pay network pharmacies for benefits provided to participating members and, therefore, act as principal in the arrangement and reflect the total prescription price as revenue, on a gross basis, in accordance with applicable accounting guidance. Costs of products and services is recognized at the time prescriptions are dispensed by pharmacies in the PBM's network to eligible members and consists primarily of ingredient costs and dispensing fees paid to retail pharmacies with which we have contracted. The overall results of our PBM business are immaterial. Aetna Part D Membership Reinsurance In November 2018, we completed the purchase of Aetna Inc.'s ("Aetna") entire standalone Medicare Part D prescription drug plan membership ("Aetna Part D membership"). In connection with the purchase, we also entered into an administrative services agreement and a reinsurance agreement pursuant to which Aetna provides administrative services to, and retains financial risk of, the Aetna Part D membership, effective for plan year 2019. We remain primarily liable to policyholders under this ceded insurance contract and are contingently liable for amounts recoverable from Aetna in the event that they do not meet their contractual obligations. In the normal course, we evaluate the financial condition of our reinsurers and monitor concentrations of credit risk to minimize our exposure to significant losses from reinsurer insolvencies. As of September 30, 2019 , related to the Aetna Part D membership, our condensed consolidated balance sheet included reinsured receivables of $167.2 million , primarily related to premiums receivable, and reinsured payables of $549.4 million , primarily related to pharmacy claims payables. These reinsured receivables and payables were included in prepaid expenses and other current assets, net, and accounts payable and accrued liabilities, respectively. The resulting net reinsurance recoverables of $382.2 million was included in prepaid expenses and other current assets, net on the condensed consolidated balance sheet. There were no reinsurance recoverables or reinsurance liabilities relating to the Aetna Part D membership recorded as of December 31, 2018 . In our condensed consolidated statement of comprehensive income, premium revenue and medical benefits were reported net of amounts ceded under this Aetna reinsurance arrangement. Premium revenue ceded relating to the Aetna Part D membership were $364.4 million and $1.3 billion for the three and nine months ended September 30, 2019 , respectively. Additionally, member benefits expense ceded relating to the Aetna Part D membership were $224.2 million and $999.2 million for the three and nine months ended September 30, 2019 , respectively. Unconsolidated Subsidiaries We work with physicians and other health care professionals to operate Accountable Care Organizations ("ACOs") under the Medicare Shared Saving Program ("MSSP") and Next Generation ACO Models. ACOs were established by the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010 (collectively, the "ACA") to reward integrated, efficient care and allow providers to share in any savings they achieve as a result of improved quality and operational efficiency. These ACOs are generally formed as limited liability companies. The ACOs are considered variable interest entities ("VIEs") under GAAP as these entities do not have sufficient equity to finance their own operations without additional financial support. We own a majority interest in our ACOs; however, we share the power to direct the activities that most significantly affect the ACOs with health care providers that are minority owners in the ACOs. This power is shared pursuant to the structure of the management committee of each of the ACOs. Accordingly, we have determined that we are not the primary beneficiary of the ACOs; therefore, we cannot consolidate their results. We perform an ongoing qualitative assessment of our variable interests in VIEs to determine whether we have a controlling financial interest and would therefore be considered the primary beneficiary of the VIE. We account for our participation in the ACOs using the equity method. Gains and losses are immaterial and are reported on the face of our condensed consolidated statements of comprehensive income as equity in earnings (losses) of unconsolidated subsidiaries. Significant Accounting Policies Below is a discussion of our significant accounting policies, which affected the comparability of our consolidated results of operations, financial condition or cash flows for the periods presented. Refer to Note 2 - Summary of Significant Accounting Policies to the consolidated financial statements included in our 2018 Form 10-K for a complete discussion of all of our significant accounting policies. Premium Receivables and Unearned Premiums We record premiums earned but not received as premiums receivable and record premiums received in advance of the period of service as unearned premiums in our condensed consolidated balance sheets. A complete discussion of premiums receivable and unearned premiums is included in Note 2 - Summary of Significant Accounting Policies to the consolidated financial statements included in our 2018 Form 10-K. The premium receivable balance at September 30, 2019 is primarily related to Medicaid contracts with our state partners of approximately $1.2 billion , as well as net risk-adjusted premiums receivable under our MA and PDP contracts of approximately $186.7 million . Medicaid Risk-Adjusted Premiums and Retroactive Rate Changes As discussed further in Note 2 - Summary of Significant Accounting Policies to the consolidated financial statements included in our 2018 Form 10-K, Medicaid premium rate changes are recognized in the period the change becomes effective, when the effect of the change in the rate is reasonably estimable and collection is assured. In some instances, our Medicaid premiums are subject to risk score adjustments based on the health profile of our membership. Generally, the risk score is determined by the state agency's analysis of encounter submissions of processed claims data to determine the acuity of our membership relative to the entire state's Medicaid membership. The frequency of when states adjust premiums varies, but is usually done quarterly or semi-annually on a retrospective basis. We recognize periodic changes to risk-adjusted premiums as revenue when the amounts are determinable and collection is reasonably assured. Premiums receivable in our condensed consolidated balance sheets include net risk-adjusted premiums receivable from our Medicaid state partners related to retroactive rate changes and risk score adjustments of $277.9 million and $54.4 million as of September 30, 2019 and December 31, 2018 , respectively. Medicare Part D Settlements We receive certain Part D prospective subsidy payments from the Centers for Medicare & Medicaid Services ("CMS") for our MA and PDP members as a fixed monthly per member amount, based on the estimated costs of providing prescription drug benefits over the plan year, as reflected in our bids. A discussion of the subsidy components under Part D is included in Note 2 - Summary of Significant Accounting Policies to the consolidated financial statements included in our 2018 Form 10-K. CMS will fully reimburse these subsidies, or recoup overpaid subsidies made during the plan year, as part of its annual settlement process that typically occurs in the fourth quarter of the subsequent year and, accordingly, there is no insurance risk to us. Therefore, amounts received for these subsidies are not considered premium revenue, and are reported, net of the subsidy benefits paid, as funds receivable (payable) for the benefit of members in the condensed consolidated balance sheets. As of December 31, 2018 , our condensed consolidated balance sheet primarily includes CMS Part D payables for the 2018 plan year. Our condensed consolidated balance sheet as of September 30, 2019 primarily includes a payable for the 2019 and 2018 plan years. We expect to settle a majority of the 2018 net payable during the remainder of 2019. ACA Industry Fee The ACA imposed certain new taxes and fees, including an annual premium-based health insurance industry assessment (the "ACA industry fee") on health insurers, which began in 2014. In January 2018, Congress approved a one-year moratorium of the ACA industry fee for 2019, which also eliminated the Medicaid ACA industry fee reimbursement from our state government partners for 2019. Accordingly, we did not incur ACA industry fee expense nor recognize any Medicaid ACA industry fee reimbursement revenue for the three and nine months ended September 30, 2019 . We incurred $86.5 million and $247.0 million for the ACA industry fee for the three and nine months ended September 30, 2018 , respectively. Additionally, we recognized $71.5 million and $199.0 million of Medicaid ACA industry fee reimbursement revenue as premium revenue for the three and nine months ended September 30, 2018 , respectively. During September 2018, we remitted a total of $388.5 million to the Internal Revenue Service ("IRS") for our portion of the ACA Industry fee assessed for 2018, including $66.5 million remitted for the recently acquired Meridian business. Recently Adopted Accounting Standards In June 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standard Update ("ASU") 2018-07, “ Compensation-Stock Compensation (Topic 718) - Improvements to Nonemployee Share-Based Payment Accounting .” This update expands the scope of Topic 718, which currently only includes share-based payments issued to employees, to include share-based payments issued to non-employees for goods and services. This guidance was effective for interim and annual periods beginning after December 15, 2018. We adopted this guidance on January 1, 2019. The adoption of this guidance did not have a material effect on our consolidated results of operations, financial condition or cash flows. In February 2018, the FASB issued ASU 2018-02 " Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income ", which allows entities to reclassify stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 from accumulated other comprehensive income to retained earnings. The guidance is effective for interim and annual periods beginning after December 15, 2018. We adopted this guidance prospectively on January 1, 2019. The adoption of this guidance did not have a material effect on our consolidated results of operations, financial condition or cash flows. In March 2017, the FASB issued ASU No. 2017-08, " Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities ". This update shortens the amortization period for the premium on certain purchased callable debt securities to the earliest call date. Previously, entities generally amortize the premium as a yield adjustment over the contractual life of the security. The new guidance does not change the accounting for purchased callable debt securities held at a discount. This guidance is effective for interim and annual periods beginning after December 15, 2018. We adopted this guidance on January 1, 2019 on a modified retrospective basis. The adoption of this guidance did not have a material effect on our consolidated results of operations, financial condition or cash flows. In February 2016, the FASB issued ASU 2016-02, “ Leases (Topic 842) ”, which for operating leases, requires a lessee to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments in its balance sheet. This standard also requires a lessee to recognize a single lease cost, calculated so that the cost of the lease is allocated over the lease term, on a generally straight-line basis. Subsequently, in July 2018, the FASB issued ASU 2018-11, “ Leases (Topic 842), Targeted Improvements ” which, among other things, allows companies to elect an optional transition method to apply the new lease standard through a cumulative-effect adjustment, if any, in the period of adoption, rather than in the earliest period presented. We adopted the standard on January 1, 2019 using the optional transition method. We elected the practical expedients permitted under the transition guidance, which allows us to carryforward our historical lease classifications for existing leases. Additionally, we elected the practical expedient to not separate non-lease components from the associated lease component. As part of the adoption process, we implemented a new lease accounting system. The adoption of this guidance resulted in the initial recognition of operating lease right-of-use assets of approximately $259.5 million , operating lease liabilities of approximately $277.3 million and the elimination of $17.8 million of straight-line lease liabilities, as of January 1, 2019. This guidance did not have a material effect on our consolidated results of operations or cash flows. Accounting Standards Pending Adoption In August 2018, the FASB issued ASU 2018-15, " Intangibles-Goodwill and Other-Internal-Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract", which requires implementation costs incurred by customers in cloud computing arrangements (i.e., hosting arrangements) to be capitalized under the same premises of authoritative guidance for internal-use software, and deferred over the noncancellable term of the cloud computing arrangements plus any option renewal periods that are reasonably certain to be exercised by the customer or for which the exercise is controlled by the service provider. The guidance is effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted. We are currently assessing the effect this guidance will have on our consolidated results of operations, financial condition or cash flows. In June 2016, the FASB issued ASU 2016-13, " Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, " which requires entities to use a current expected credit loss model, which is a new impairment model based on expected losses rather than incurred losses. Under this model, an entity would recognize an impairment allowance equal to its current estimate of all contractual cash flows that the entity does not expect to collect from financial assets measured at amortized cost. The entity's estimate would consider relevant information about past events, current conditions, and reasonable and supportable forecasts, which will result in recognition of lifetime expected credit losses upon loan origination. ASU 2016-13 is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted for annual reporting periods beginning after December 15, 2018. We are currently assessing the effect this guidance will have on our consolidated results of operations, financial condition or cash flows.

CENTENE PLAN OF MERGER, PROPOSE

CENTENE PLAN OF MERGER, PROPOSED DIVESTITURES AND COMPLETED ACQUISITIONS	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
CENTENE PLAN OF MERGER, PROPOSED DIVESTITURES AND COMPLETED ACQUISITIONS	CENTENE PLAN OF MERGER, PROPOSED DIVESTITURES AND COMPLETED ACQUISITIONS Centene Plan of Merger On March 26, 2019, we entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Centene Corporation ("Centene") under which Centene will acquire us for a combination of cash and stock (the "Centene Transaction"). Under the terms of the Merger Agreement, our shareholders will receive $120.00 in cash and 3.38 shares of Centene common stock for each share of our common stock. On June 24, 2019, stockholders of both companies approved all proposals regarding the Centene Transaction. Completion of the Centene Transaction remains subject to the receipt of U.S. federal antitrust clearance and certain other required regulatory approvals. The Centene Transaction is expected to close in the first half of 2020. The Merger Agreement includes restrictions on the conduct of our business prior to completion of the Centene Transaction or termination of the Merger Agreement, generally requiring us to conduct our business in the ordinary course. However, we are subject to various specified restrictions unless we obtain Centene’s prior written consent, which may not be unreasonably withheld, delayed or conditioned, or expressly contemplated or permitted by the Merger Agreement or as required by applicable law. Among other things and in each case subject to certain exceptions, we may not: • incur additional indebtedness (excluding borrowings under our Revolving Credit Facility (as defined below) that are used to manage our ordinary course cash flow needs); • issue additional shares of our common stock, repurchase our common stock, or pay dividends; • acquire assets, securities or property, dispose of businesses or assets; or • authorize any payment of, accrual or commitment for capital expenditures in any calendar year that would exceed by more than 110% the aggregate amount of capital expenditures budgeted for such year. Proposed Divestitures On September 26, 2019, in connection with the previously announced Centene Transaction, we entered into a definitive agreement with Anthem, Inc. ("Anthem") under which Anthem will acquire our Missouri and Nebraska health plans. The closing of the transaction with Anthem is subject to U.S. federal antitrust clearance, receipt of state regulatory approvals and certain other customary closing conditions, as well as the closing of the Centene Transaction. The sale price is not material and the transaction is not expected to have a material effect on our consolidated results of operations, financial condition or cash flows. Aetna Medicare Part D Asset Acquisition As discussed in Note 1 - Organization, Basis of Presentation and Significant Accounting Policies of this 2019 Form 10-Q, we completed the purchase of Aetna's Part D membership for total cash consideration of $115.8 million , including subsequent purchase price adjustments. These membership assets are recorded within other intangible assets, net in the condensed consolidated balance sheets as of September 30, 2019 and December 31, 2018 , and have a weighted-average useful life of eight years beginning in 2020. Per the terms of the agreement, Aetna provides administrative services to, and retains financial risk of, the Aetna Part D membership through 2019. Therefore, the Aetna Part D membership is excluded from our membership and has had, or is expected to have, an immaterial effect on our results of operations until January 1, 2020. Meridian Business Acquisition On September 1, 2018 (the "Effective Date"), we acquired Meridian for an estimated purchase price of approximately $2.5 billion in cash, subject to certain purchase price adjustments, as described in the purchase agreement. The Meridian acquisition was funded through a combination of cash on hand, our Revolving Credit Facility, net proceeds from the August 2018 issuance of our 5.375% of Senior Notes due 2026 ("2026 Notes") and net proceeds from an issuance of shares of our common stock. We included the results of Meridian's operations since the Effective Date in our condensed consolidated financial statements. The following table summarizes the final fair values of major classes of assets acquired and liabilities assumed at the Effective Date, based on our valuation assumptions, reconciled to the total consideration transferred. Assets (in millions) Cash, cash equivalents and restricted cash $ 484.4 Investments, including restricted investments 180.4 Premiums receivable, net 379.6 Other current assets 139.2 Property, equipment and capitalized software, net 49.3 Goodwill 1,598.2 Other intangible assets, net 543.5 Fair value of total assets acquired $ 3,374.6 Liabilities Medical benefits payable $ 534.3 ACA Fee liability 66.5 Other liabilities 253.7 Fair value of liabilities assumed 854.5 Fair value of net assets acquired $ 2,520.1 The fair value results from judgments about future events, which reflect certain uncertainties and rely on estimates and assumptions. The judgments used to determine the fair value assigned to each class of assets acquired and liabilities assumed, as well as intangible asset lives, can materially affect our operating results. As of the Effective Date, the expected fair value of all current assets and liabilities approximated their historical cost. For certain noncurrent assets and liabilities, we have made fair value adjustments based on information reviewed through the end of the measurement period. Identifiable intangible assets acquired As disclosed at December 31, 2018, under the Hart-Scott-Rodino Antitrust Improvements Act and other relevant laws and regulations, there were significant limitations on our ability to obtain specific information about Meridian's intangible assets prior to completion of the acquisition in September 2018. As a result, certain assumptions inherent in the development of intangible asset fair values were preliminary as of December 31, 2018. During the nine months ended September 30, 2019, we received updated information regarding facts and circumstances which existed as of the Effective Date that affected certain assumptions utilized in the preliminary purchase price valuation. As a result, we recorded measurement period adjustments, which reduced total identifiable intangible assets and deferred tax liabilities by $50.5 million and $22.9 million , respectively, during the nine months ended September 30, 2019. These two items and certain working capital adjustments as of the Effective Date, resulted in a net increase to goodwill. The effect to our statement of operations was immaterial for all periods presented. As of September 30, 2019, our final allocation of the Meridian purchase price to identifiable intangible assets acquired reflects our final assumptions of membership attrition rates, discount rates selected to measure the risks inherent in the future cash flows and working capital adjustments. The following table summarizes the final fair values and weighted average useful lives for identifiable intangible assets acquired in the Meridian acquisition as of the Effective Date of the acquisition. Gross Fair Value (in millions) Weighted Average Useful Life (in years) Membership $ 326.8 8.2 Tradenames 113.8 4.9 Provider network 8.3 15.0 Technology and other 94.6 5.8 Total $ 543.5 7.2 Goodwill We recorded $1.6 billion for the valuation of goodwill for the excess of the purchase price over the estimated fair value of the net assets acquired and primarily represents synergies expected from the acquisition and the assembled workforce. The recorded goodwill related to the acquisition is deductible for tax purposes. Deferred taxes The Meridian acquisition included taxable and nontaxable components resulting in differences in amounts recognized for GAAP and tax purposes. In both taxable and nontaxable business combinations, the amounts assigned to the individual assets acquired and liabilities assumed for financial statement purposes are often different from the amounts assigned or carried forward for tax purposes. We recorded a $23.6 million deferred tax liability based on the estimated bases differences. Goodwill A summary of changes in our goodwill, including the allocation of Meridian goodwill, by reportable segment is as follows for the nine months ended September 30, 2019 : Medicaid Health Plans Medicare Health Plans Corporate and Other Not Assigned Total Balance as of December 31, 2018 $ 274.7 $ 392.3 $ — $ 1,560.7 $ 2,227.7 Acquisition related adjustments 1,416.3 119.0 62.9 (1,560.7 ) 37.5 Balance as of September 30, 2019 $ 1,691.0 $ 511.3 $ 62.9 $ — $ 2,265.2 Unaudited Pro Forma Financial Information The results of operations and financial condition for the Meridian acquisition have been included in our condensed consolidated financial statements since the Effective Date. The unaudited pro forma financial information presented below reflects our 2018 acquisition of Meridian, assuming the acquisition occurred as of January 1, 2018. Pro forma results are not provided for the three and nine months ended September 30, 2019 , as Meridian's operations were included in our results of operations for this time period. These pro forma results are based on estimates and assumptions and do not reflect any anticipated synergies, efficiencies or other cost savings that we expect to realize from the acquisition. The following unaudited pro forma results have been prepared for comparative purposes only and do not purport to be indicative of the results of operations that would have occurred had the acquisition actually consummated at January 1, 2018, or project the future results of the combined company. Pro Forma - Unaudited (in millions, except per share data) Three Months Ended Nine Months Ended Total revenues $ 5,869.8 $ 17,337.8 Net income $ 106.9 $ 355.2 Earnings per common share: Basic $ 2.14 $ 7.12 Diluted $ 2.11 $ 7.03 Weighted average common shares outstanding: Basic 49,976,863 49,949,219 Diluted 50,648,578 50,514,031 The pro forma results presented in the schedule above include adjustments related to the following purchase accounting and other acquisition-related costs: • Elimination of historical intangible asset amortization expense and addition of amortization expense based on the current preliminary values of identified intangible assets; • Elimination of interest expense associated with retired obligations and addition of interest expense based on debt incurred to finance the Meridian transaction; • Elimination of results for Meridian operations not acquired; • Elimination of transaction and integration-related costs; • Include 5,207,547 shares of our common stock issued to finance the Meridian transaction; • Adjustments to align the acquisition to our accounting policies; and • Tax effects of the adjustments noted above.

SEGMENT REPORTING

SEGMENT REPORTING	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
SEGMENT REPORTING	SEGMENT REPORTING On a regular basis, we evaluate discrete financial information and assess the performance of our three reportable segments Medicaid Health Plans, Medicare Health Plans and Medicare PDPs, to determine the most appropriate use and allocation of Company resources. We allocate premium revenue, medical benefits expense, Medicaid premium taxes, the 2018 ACA industry fee and goodwill to our reportable segments. We do not allocate to our reportable segments any other assets and liabilities, investment and other income, selling, general and administrative expenses ("SG&A"), depreciation and amortization, or interest expense. The Company's decision-makers primarily use premium revenue, medical benefits expense and gross margin to evaluate the performance of our reportable segments. Our Corporate and Other category includes net investment and other income, SG&A expenses, depreciation, amortization and interest. Also included in this category are results for operating segments that are not individually reportable because they do not meet the quantitative thresholds required by generally accepted accounting principles. Medicaid Health Plans Our Medicaid Health Plans segment includes plans for beneficiaries of Temporary Assistance for Needy Families ("TANF"), Supplemental Security Income ("SSI"), Aged Blind and Disabled ("ABD"), Children's Health Insurance Program ("CHIP") and Long-Term Services and Supports ("LTSS") programs, among others. TANF generally provides assistance to low-income families with children. ABD and SSI generally provide assistance to low-income aged, blind or disabled individuals. CHIP provides assistance to qualifying families who are not eligible for Medicaid because their income exceeds the applicable income thresholds. The LTSS program is designed to help people with chronic illnesses or who have disabilities and need health and long-term care services, such as home care or adult day care, to enable them to stay in their homes and communities as long as possible. Our Medicaid operations in Florida, Illinois and Kentucky individually account for 10% or more of our consolidated premium revenue for the three and nine months ended September 30, 2019 . These states and the respective Medicaid premium revenue as a percentage of total consolidated premium revenue are as follows: For the Three Months Ended For the Nine Months Ended 2019 2018 2019 2018 Florida 20% 13% 19% 13% Illinois 13% * 13% * Kentucky 10% 13% 10% 14% *Our Illinois Medicaid health plan accounted for less than 10% of our consolidated premium revenue for the three and nine months ended September 30, 2018. On February 1, 2019, we began providing statewide-managed care services to children with medically complex conditions through the Children's Medical Services Managed Care Plan ("CMS Plan") contract from the Florida Department of Health. On December 1, 2018, we began providing managed care services to Medicaid-eligible beneficiaries, including Managed Medical Assistance and Long-Term Care beneficiaries in 10 of 11 regions in Florida through a new five-year contract. As part of the Medicaid Managed Care program, we are one of two managed care plans providing statewide-managed care services to beneficiaries in the Serious Mental Illness Specialty Plan. Medicare Health Plans Medicare is a federal program that provides eligible persons age 65 and over and some disabled persons with a variety of hospital, medical and prescription drug benefits. MA is Medicare's managed care alternative to the original Medicare program, which provides individuals standard Medicare benefits directly through CMS. Our MA CCPs generally require members to seek health care services and select a primary care physician from a network of health care providers. In addition, we offer coverage of prescription drug benefits under the Medicare Part D program as a component of most of our MA plans. Medicare PDPs We offer stand-alone Medicare Part D coverage to Medicare-eligible beneficiaries in our Medicare PDPs segment. The Medicare Part D prescription drug benefit is supported by risk sharing with the federal government through risk corridors designed to limit the losses and gains of the participating drug plans and by reinsurance for catastrophic drug costs. The government subsidy is based on the national weighted average monthly bid for this coverage, adjusted for risk factor payments. Additional subsidies are provided for dually-eligible beneficiaries and specified low-income beneficiaries. The Part D program offers national in-network prescription drug coverage that is subject to limitations in certain circumstances. Summary of Financial Information Reportable operating segments are defined as components of an enterprise for which discrete financial information is available and evaluated on a regular basis by the enterprise's decision-makers to determine how resources should be allocated to an individual segment and to assess performance of those segments. Accordingly, we have three reportable segments: Medicaid Health Plans, Medicare Health Plans and Medicare PDPs. A summary of financial information for our reportable segments through the gross margin level and reconciliation to income from operations is presented in the table below. Medicaid Health Plan Medicare Health Plan Medicare PDP Corporate & Other Consolidated For the Three Months Ended September 30, 2019 (in millions) Premium $ 4,877.5 $ 1,841.4 $ 241.2 $ 5.5 $ 6,965.6 Products and services — — — 132.1 132.1 Total premium and products and services revenues 4,877.5 1,841.4 241.2 137.6 7,097.7 Medical benefits 4,308.7 1,533.5 182.7 0.8 6,025.7 Costs of products and services — — — 128.9 128.9 ACA industry fee — — — — — Medicaid premium taxes 35.6 — — — 35.6 Total gross margin expenses 4,344.3 1,533.5 182.7 129.7 6,190.2 Gross margin 533.2 307.9 58.5 7.9 907.5 Investment and other income — — — 42.5 42.5 Other expenses — — — (656.7 ) (656.7 ) Income from operations $ 533.2 $ 307.9 $ 58.5 $ (606.3 ) $ 293.3 For the Three Months Ended September 30, 2018 Premium $ 3,223.3 $ 1,582.0 $ 182.3 $ 1.2 $ 4,988.8 Products and services — — — 34.6 34.6 Total premium and products and services revenues 3,223.3 1,582.0 182.3 35.8 5,023.4 Medical benefits 2,738.1 1,340.8 115.1 1.0 4,195.0 Costs of products and services — — — 33.5 33.5 ACA industry fee 54.4 27.5 4.6 — 86.5 Medicaid premium taxes 31.5 — — — 31.5 Total gross margin expenses 2,824.0 1,368.3 119.7 34.5 4,346.5 Gross margin 399.3 213.7 62.6 1.3 676.9 Investment and other income — — — 34.7 34.7 Other expenses — — — (503.0 ) (503.0 ) Income from operations $ 399.3 $ 213.7 $ 62.6 $ (467.0 ) $ 208.6 Medicaid Health Plan Medicare Health Plan Medicare PDP Corporate & Other Consolidated For the Nine Months Ended September 30, 2019 (in millions) Premium $ 14,055.8 $ 5,557.3 $ 789.3 $ 14.8 $ 20,417.2 Products and services — — — 374.6 374.6 Total premium and products and services revenues 14,055.8 5,557.3 789.3 389.4 20,791.8 Medical benefits 12,599.5 4,627.2 651.7 6.1 17,884.5 Costs of products and services — — — 363.9 363.9 ACA industry fee — — — — — Medicaid premium taxes 99.0 — — — 99.0 Total gross margin expenses 12,698.5 4,627.2 651.7 370.0 18,347.4 Gross margin 1,357.3 930.1 137.6 19.4 2,444.4 Investment and other income — — — 120.7 120.7 Other expenses — — — (1,845.6 ) (1,845.6 ) Income from operations $ 1,357.3 $ 930.1 $ 137.6 $ (1,705.5 ) $ 719.5 For the Nine Months Ended September 30, 2018 Premium $ 8,899.4 $ 4,684.9 $ 642.2 $ 1.2 $ 14,227.7 Products and services — — — 34.6 34.6 Total premium and products and services revenues 8,899.4 4,684.9 642.2 35.8 14,262.3 Medical benefits 7,601.1 3,929.8 491.1 1.0 12,023.0 Costs of products and services — — — 33.5 33.5 ACA industry fee 151.5 81.8 13.7 — 247.0 Medicaid premium taxes 94.2 — — — 94.2 Total gross margin expenses 7,846.8 4,011.6 504.8 34.5 12,397.7 Gross margin 1,052.6 673.3 137.4 1.3 1,864.6 Investment and other income — — — 81.0 81.0 Other expenses — — — (1,341.9 ) (1,341.9 ) Income from operations $ 1,052.6 $ 673.3 $ 137.4 $ (1,259.6 ) $ 603.7

EQUITY AND EARNINGS PER SHARE

EQUITY AND EARNINGS PER SHARE	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
EQUITY AND EARNINGS PER SHARE	EQUITY AND EARNINGS PER SHARE Issuance of Common Stock In August 2018, we completed a public offering of our common stock and issued 5,207,547 shares of our common stock, at an offering price of $265.00 per share. The net proceeds from the offering were approximately $1.3 billion , after deducting underwriting discounts and offering costs of approximately $37.7 million . We used the net proceeds to fund a portion of the acquisition of Meridian. Earnings per Common Share We compute basic earnings per common share on the basis of the weighted-average number of unrestricted common shares outstanding. We compute diluted earnings per common share on the basis of the weighted-average number of unrestricted common shares outstanding plus the dilutive effect of our stock-based compensation awards using the treasury stock method. The calculation of the weighted-average common shares outstanding — diluted is as follows: For the Three Months Ended For the Nine Months Ended 2019 2018 2019 2018 Weighted-average common shares outstanding — basic 50,313,901 47,712,712 50,240,480 45,692,804 Dilutive effect of outstanding stock-based compensation awards 532,501 671,715 593,024 594,812 Weighted-average common shares outstanding — diluted 50,846,402 48,384,427 50,833,504 46,287,616 Anti-dilutive stock-based compensation awards excluded from computation 121,960 136,428 104,439 184,964

INVESTMENTS

INVESTMENTS	9 Months Ended
	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
INVESTMENTS	INVESTMENTS The Company considers all of its investments as available-for-sale securities. Excluding restricted cash, cash equivalents and investments, the amortized cost, gross unrealized gains or losses and estimated fair value of short-term and long-term investments by security type are summarized in the following tables. Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value September 30, 2019 Debt securities: Asset-backed securities $ 367.5 $ 1.3 $ (0.1 ) $ 368.7 Corporate debt securities 1,516.1 11.5 (1.3 ) 1,526.3 Municipal securities 154.6 3.2 (0.1 ) 157.7 Residential mortgage-backed securities 307.2 1.0 (0.4 ) 307.8 Short-term time deposits 137.2 — — 137.2 Government and agency obligations 26.4 — — 26.4 Other securities 149.2 0.8 (0.3 ) 149.7 Total debt securities 2,658.2 17.8 (2.2 ) 2,673.8 Equity securities (1) 468.5 — — 468.5 Total $ 3,126.7 $ 17.8 $ (2.2 ) $ 3,142.3 December 31, 2018 Asset-backed securities $ 144.7 $ — $ (0.5 ) $ 144.2 Corporate debt securities 943.0 0.5 (10.1 ) 933.4 Municipal securities 199.6 0.6 (0.9 ) 199.3 Residential mortgage-backed securities 7.2 — (0.2 ) 7.0 Short-term time deposits 242.2 — — 242.2 Government and agency obligations 44.9 — (0.1 ) 44.8 Other securities 72.5 — (0.1 ) 72.4 Total (1) $ 1,654.1 $ 1.1 $ (11.9 ) $ 1,643.3 (1) Investments in equity securities primarily consists of exchange traded funds in fixed income and preferred and hybrid securities. Equity securities were not material as of December 31, 2018. As of September 30, 2019, approximately 97% of our investments consist of investment-grade debt securities. These investment-grade securities have a weighted average credit rating of A+ as designated by a nationally recognized statistical rating organization. The below investment-grade debt securities have a weighted average credit rating of BB (the higher end of the below investment-grade rating scale). Contractual maturities of debt securities at September 30, 2019 are as follows: Amortized Cost Fair Value Due in one year or less $ 952.4 $ 953.2 Due after one year through five years 676.7 682.6 Due after five years through ten years 221.4 227.8 Due after ten years 26.6 26.8 Asset-backed and mortgage-backed securities 781.1 783.4 Total $ 2,658.2 $ 2,673.8 Actual maturities may differ from contractual maturities due to the exercise of pre-payment options. We sold available-for-sale investments totaling $ 1.4 billion and $252.4 million during the three months ended September 30, 2019 and 2018 , respectively, and $2.8 billion and $471.2 million during the nine months ended September 30, 2019 and 2018 , respectively. Realized gains and losses resulting from sales and redemptions of our available-for-sale investments were immaterial for all periods presented. Additionally, we did not realize any other-than-temporary impairment during any of these periods.

RESTRICTED CASH, CASH EQUIVALEN

RESTRICTED CASH, CASH EQUIVALENTS AND INVESTMENTS	9 Months Ended
	Sep. 30, 2019
Restricted Investments Note [Abstract]
RESTRICTED CASH, CASH EQUIVALENTS AND INVESTMENTS	RESTRICTED CASH, CASH EQUIVALENTS AND INVESTMENTS As a condition for licensure, we are required to maintain certain funds on deposit or pledged to various state agencies. Certain of our state contracts require the issuance of surety bonds. We classify restricted cash, cash equivalents and investments as long-term regardless of the contractual maturity date of the securities held, due to the nature of the states' requirements. The amortized cost, gross unrealized gains, gross unrealized losses and fair value of our restricted cash, cash equivalents and investment securities are as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value September 30, 2019 Cash $ 4.7 $ — $ — $ 4.7 Money market funds 121.6 — — 121.6 U.S. government securities and other 191.6 — — 191.6 Total $ 317.9 $ — $ — $ 317.9 December 31, 2018 Cash $ 11.3 $ — $ — $ 11.3 Money market funds 51.4 — — 51.4 U.S. government securities and other 172.5 — (0.5 ) 172.0 Total $ 235.2 $ — $ (0.5 ) $ 234.7 Realized gains and losses on sales and redemptions of our restricted cash, cash equivalents and investments were not material for the three and nine months ended September 30, 2019

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION Certain of our employees, including executive officers, are eligible for long-term incentive awards ("LTI Program"), consisting of equity awards granted pursuant to the WellCare Health Plans, Inc. 2013 Incentive Compensation Plan (the "2013 Plan") and the WellCare Health Plans, Inc. 2019 Incentive Compensation Plan (the "2019 Plan"). During the second quarter of 2019, our stockholders approved the 2019 Plan. Upon approval of the 2019 Plan, approximately 1,600,000 shares of our common stock were available for issuance pursuant to the 2019 Plan. In addition, shares subject to awards forfeited, terminated or expired under the 2013 Plan will become available for issuance under the 2019 Plan. No further awards are permitted to be granted under our 2013 Plan. We designed the LTI Program to motivate and promote the achievement of our long-term financial and operating goals and improve retention. Under the LTI Program, we grant multi-year performance period awards and time-based awards. The award amounts and allocation amongst the different types of awards are based on job level. The Compensation Committee of our board of directors (the "Compensation Committee") evaluates our results with respect to the pre-established performance criteria and determines the ultimate payout amount of the performance stock units. Our Compensation Committee awards certain equity-based compensation under our stock plans, including restricted stock units ("RSUs") and performance stock units ("PSUs"). Compensation expense related to our stock-based compensation awards was $17.1 million and $21.4 million for the three months ended September 30, 2019 and 2018 , respectively, and $58.9 million and $51.5 million for the nine months ended September 30, 2019 and 2018 , respectively. As of September 30, 2019 , there was $89.4 million of unrecognized compensation cost related to unvested stock-based compensation arrangements that is expected to be recognized over a weighted-average period of 1.7 years . The unrecognized compensation cost for certain of our PSUs, which are subject to variable accounting, was determined based on our closing common stock price of $259.17 as of September 30, 2019 and amounted to approximately $23.7 million of the total unrecognized compensation cost. Due to the nature of the accounting for these awards, future compensation cost will fluctuate based on changes in our common stock price. We estimate stock-based compensation expense based on awards ultimately expected to vest over the related service period (generally the vesting period) of the award, or to an employee’s eligible retirement date under the award agreement, if earlier. We make assumptions of forfeiture rates at the time of grant and continuously reassess our assumptions based on actual forfeiture experience. A summary of RSU and PSU award activity, at target, for the nine months ended September 30, 2019 , is presented in the table below. For our PSUs, shares attained over target upon vesting are reflected as awards granted during the period, while shares canceled due to vesting below target are reflected as awards forfeited during the period. RSUs PSUs Total Outstanding as of January 1, 2019 253,235 606,708 859,943 Granted 113,276 352,683 465,959 Vested (126,103 ) (360,344 ) (486,447 ) Forfeited (13,959 ) (32,096 ) (46,055 ) Outstanding as of September 30, 2019 226,449 566,951 793,400 The weighted-average grant-date fair value of all equity awards granted during the nine months ended September 30, 2019 was $308.55 . Refer to Note 2 - Summary of Significant Accounting Policies and Note 15 - Stock-based Compensation to the consolidated financial statements included in our 2018 Form 10-K for additional information regarding our equity-compensation awards and related compensation cost measurement.

DEBT

DEBT	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
DEBT	DEBT The following table summarizes our outstanding debt obligations and their classification in the accompanying condensed consolidated balance sheets (in millions): September 30, 2019 December 31, 2018 Long-term debt, net: 5.25% Senior Notes, due April 1, 2025 $ 1,200.0 $ 1,200.0 5.375% Senior Notes, due August 15, 2026 750.0 750.0 Revolving Credit Facility 100.0 200.0 Debt issuance costs (20.9 ) (23.6 ) Total long-term debt, net $ 2,029.1 $ 2,126.4 Senior Notes In August 2018, we completed the offering and sale of 5.375% unsecured senior notes due 2026 in the aggregate principal amount of $ 750.0 million (the “2026 Notes”). The aggregate net proceeds from the issuance of the 2026 Notes were used to fund a portion of the cash consideration for our acquisition of Meridian. In March 2017, we completed the offering and sale of 5.25% unsecured senior notes due 2025 in the aggregate principal amount of $1,200.0 million (the “2025 Notes”). The aggregate net proceeds from the issuance of the 2025 Notes were primarily used to redeem the full $900.0 million aggregate principal amount of our 5.75% unsecured senior notes (the "2020 Notes") on April 7, 2017, and for general corporate purposes, including organic growth and working capital. The 2026 Notes and 2025 Notes are classified as long-term debt in our condensed consolidated balance sheet at September 30, 2019 , based on their maturity date. Refer to Note 10 - Debt to the consolidated financial statements included in our 2018 Form 10-K for additional information regarding these 2026 Notes and 2025 Notes, including applicable covenants. Revolving Credit Facility In January 2016, we entered into a credit agreement, which provided for a senior unsecured revolving loan facility (the "Revolving Credit Facility"). In July 2018, this credit agreement was amended and restated (“Amended and Restated Credit Agreement”) to increase the aggregate principle amount available under our Revolving Credit Facility from $1.0 billion to $1.3 billion , extend the maturity date for borrowings under the Revolving Credit Facility from January 2021 to July 2023 and decrease the applicable margins for borrowings under the Revolving Credit Facility, as calculated in accordance with the Amended and Restated Credit Agreement. The Amended and Restated Credit Agreement also includes an accordion feature which allows the Company to increase the total commitments under the Revolving Credit Facility by up to an additional $500 million , subject to certain conditions. Unutilized commitments under the Amended and Restated Credit Agreement are subject to a fee of 0.20% to 0.30% depending upon our ratio of total debt to consolidated EBITDA, as calculated in accordance with the Amended and Restated Credit Agreement. During the nine months ended September 30, 2019 , we made net repayments of $100.0 million on the outstanding balance under our Revolving Credit Facility, and as a result, there was $100.0 million outstanding as of September 30, 2019 . These borrowings are classified as long-term debt in accordance with the contractual terms of the Amended and Restated Credit Agreement. As of September 30, 2019

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Our condensed consolidated balance sheets include the following financial instruments: cash and cash equivalents, investments, receivables, accounts payable, medical benefits payable, long-term debt, including any current portion of long-term debt, and other liabilities. We consider the carrying amounts of cash and cash equivalents, receivables, other current assets and current liabilities to approximate their fair value due to the short period of time between the origination of these instruments and the expected realization or payment. Certain assets and liabilities are measured at fair value on a recurring basis and are disclosed below. These assets and liabilities are classified into one of three levels of a hierarchy defined by GAAP. For a description of the methods and assumptions that are used to estimate the fair value and determine the fair value hierarchy classification of each class of financial instrument, see the consolidated financial statements and notes thereto included in our 2018 Form 10-K. Recurring Fair Value Measurements Assets and liabilities measured at fair value on a recurring basis at September 30, 2019 are as follows: Fair Value Measurements Using Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investments: Debt securities: Asset-backed securities $ 368.7 $ — $ 368.7 $ — Corporate debt securities 1,526.3 — 1,526.3 — Municipal securities 157.7 — 157.7 — Residential mortgage-backed securities 307.8 — 307.8 — Short-term time deposits 137.2 — 137.2 — Government and agency obligations 26.4 26.4 — — Other securities 149.7 42.9 106.8 — Total debt securities 2,673.8 69.3 2,604.5 — Equity securities (1) 468.5 466.4 2.1 — Total investments $ 3,142.3 $ 535.7 $ 2,606.6 $ — Restricted cash, cash equivalents and investments: Cash $ 4.7 $ 4.7 $ — $ — Money market funds 121.6 121.6 — — U.S. government securities and other 191.6 191.4 0.2 — Total restricted cash, cash equivalents and investments $ 317.9 $ 317.7 $ 0.2 $ — (1) Investments in equity securities primarily consists of exchange traded funds in fixed-income and preferred and hybrid securities. Assets and liabilities measured at fair value on a recurring basis at December 31, 2018 are as follows: Fair Value Measurements Using Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investments: Asset-backed securities $ 144.2 $ — $ 144.2 $ — Corporate debt securities 933.4 — 933.4 — Municipal securities 199.3 — 199.3 — Residential mortgage-backed securities 7.0 — 7.0 — Short-term time deposits 242.2 — 242.2 — Government and agency obligations 44.8 44.8 — — Other securities 72.4 49.8 22.6 — Total Investments (1) $ 1,643.3 $ 94.6 $ 1,548.7 $ — Restricted cash, cash equivalents and investments: Cash $ 11.3 $ 11.3 $ — $ — Money market funds 51.4 51.4 — — U.S. government securities and other 172.0 171.8 0.2 — Total restricted cash, cash equivalents and investments $ 234.7 $ 234.5 $ 0.2 $ — (1) Equity securities were not material as of December 31, 2018. The following table presents the carrying value and fair value of our long-term debt outstanding as of September 30, 2019 and December 31, 2018 : Fair Value Measurements Using Carrying Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Long-term debt - September 30, 2019 2,029.1 2,054.4 100.0 — Long-term debt - December 31, 2018 2,126.4 1,885.2 200.0 — The fair value of our 2026 Notes and 2025 Notes were determined based on quoted market prices; therefore, would be classified within Level 1 of the fair value hierarchy. The fair value of obligations outstanding under our Revolving Credit Facility, as of September 30, 2019 and December 31, 2018

MEDICAL BENEFITS PAYABLE

MEDICAL BENEFITS PAYABLE	9 Months Ended
	Sep. 30, 2019
MEDICAL BENEFITS PAYABLE [Abstract]
MEDICAL BENEFITS PAYABLE	MEDICAL BENEFITS PAYABLE A reconciliation of the beginning and ending balances of medical benefits payable, by segment, is as follows: For the Nine Months Ended September 30, 2019 Medicaid Health Plans Medicare Health Plans Medicare PDPs Corporate and Other (2) Consolidated Beginning balance (1) $ 2,012.8 $ 823.5 $ 59.1 $ 2.0 $ 2,897.4 Acquisitions — — — — — Medical benefits incurred related to: Current year 12,885.1 4,732.1 700.2 7.2 18,324.6 Prior years (285.6 ) (104.9 ) (48.5 ) (1.1 ) (440.1 ) Total 12,599.5 4,627.2 651.7 6.1 17,884.5 Medical benefits paid related to: Current year (10,936.0 ) (3,858.4 ) (628.4 ) (5.5 ) (15,428.3 ) Prior years (1,384.3 ) (600.7 ) (3.8 ) (0.9 ) (1,989.7 ) Total (12,320.3 ) (4,459.1 ) (632.2 ) (6.4 ) (17,418.0 ) Ending balance (1) $ 2,292.0 $ 991.6 $ 78.6 $ 1.7 $ 3,363.9 (1) The Medicaid Health Plans and Consolidated beginning balance for 2019 include a premium deficiency reserve for our Illinois Medicaid programs ("Illinois PDR"), which amounted to $16.1 million at December 31, 2018 . There was no Illinois PDR at September 30, 2019. See Note 2 - Summary of Significant Accounting Policies in our 2018 Form 10-K for further discussion. (2) The Corporate and Other category includes operating segments that are not individually reportable because they do not meet the quantitative thresholds required by generally accepted accounting principles. For the Nine Months Ended September 30, 2018 Medicaid Health Plans Medicare Health Plans Medicare PDPs Corporate and Other Consolidated Beginning balance (1) $ 1,373.2 $ 722.5 $ 50.6 $ — $ 2,146.3 Acquisitions 478.2 47.1 — 2.7 528.0 Medical benefits incurred related to: Current year 7,803.2 4,051.6 560.4 1.0 12,416.2 Prior years (202.1 ) (121.8 ) (69.3 ) — (393.2 ) Total 7,601.1 3,929.8 491.1 1.0 12,023.0 — Medical benefits paid related to: Current year (6,562.2 ) (3,382.3 ) (502.9 ) (0.8 ) (10,448.2 ) Prior years (889.3 ) (488.3 ) 30.0 (0.1 ) (1,347.7 ) Total (7,451.5 ) (3,870.6 ) (472.9 ) (0.9 ) (11,795.9 ) Ending balance (1) $ 2,001.0 $ 828.8 $ 68.8 $ 2.8 $ 2,901.4 (1) The Medicaid Health Plans and Consolidated beginning and ending balances for 2018 include a premium deficiency reserve for our Illinois Medicaid program ("Illinois PDR"), which amounted to $20.6 million and $45.6 million at September 30, 2018 and December 31, 2017, respectively. We recognize the cost of medical benefits in the period in which services are provided, including an estimate of the cost of medical benefits incurred but not reported ("IBNR"). Medical benefits expense includes direct medical expenses and certain medically-related administrative costs. We evaluate our estimates of medical benefits payable as we obtain more complete claims information and medical expense trend data over time. We record differences between actual experience and estimates used to establish the liability, which we refer to as favorable and unfavorable prior year reserve developments, as increases or decreases to medical benefits expense in the period we identify the differences. Medical benefits payable developed favorably by approximately $440.1 million and $393.2 million for the nine months ended September 30, 2019 and 2018 , respectively. The release of the provision for moderately adverse conditions included in our prior year estimates was substantially offset by the provision for moderately adverse conditions established for claims incurred in the current year. Accordingly, the favorable development in our estimate of medical benefits payable related to claims incurred in prior years does not directly correspond to a decrease in medical benefits expense recognized during the period in which the favorable development is recognized. Excluding the prior year development related to the release of the provision for moderately adverse conditions, our estimates of consolidated medical benefits payable developed favorably by approximately $247.0 million and $215.2 million for the nine months ended September 30, 2019 and 2018 , respectively. Such amounts are net of the development relating to refunds due to government customers with minimum loss ratio provisions. The net favorable development recognized in both 2019 and 2018 resulted primarily due to a number of operational and clinical initiatives planned and executed, that contributed to lower than expected pharmacy and medical trends, and actual claim submission time being faster than we originally assumed (i.e., our completion factors were higher than we originally assumed) in establishing our medical benefits payable in the prior years. This development does not directly correspond to an increase in our current year operating results as these reductions were offset by estimated current period medical benefits expense when we established our estimate of the current year medical benefits payable. Both completion factor and medical trend assumptions are influenced by utilization levels, unit costs, mix of business, provider reimbursement levels, processing system conversions and changes, claim inventory levels, claim processing patterns, our ability and practices to manage medical and pharmaceutical costs, claim submission patterns and operational changes resulting from business combinations, among others. Our actual costs were ultimately less than expected. Our Meridian acquisition in September 2018 resulted in an increase to medical benefits payable as of the acquisition date. See Note 2 - Centene Plan of Merger, Proposed Divestitures and Completed Acquisitions , for additional information on the Meridian acquisitions.

LEASES

LEASES	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
LEASES	LEASES In determining whether a contract contains a lease, we assess whether the arrangement meets all three of the following criteria: 1) there is an identified asset; 2) we have the right to obtain substantially all the economic benefits from use of the identified asset; and 3) we have the right to direct the use of the identified asset. This involves evaluating whether we have the right to operate the asset or to direct others to operate the asset in a manner that it determines without the supplier having the right to change those operating instructions, as well as evaluating our involvement in the design of the asset. We have right-of-use assets and liabilities for non-cancelable operating leases primarily for office space, data centers and other equipment. Our leases have remaining lease terms up to approximately 14 years. The depreciable life of assets and leasehold improvements are limited by the expected lease term. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. For the three and nine months ended September 30, 2019 operating lease expense of $19.0 million and $53.7 million , respectively, was recorded as SG&A expense in our condensed consolidated statement of comprehensive income. Balance sheet information related to our operating leases was as follows (in millions): Classification September 30, 2019 Assets: Right of use assets Other assets $ 247.0 Liabilities: Current Accounts payable and accrued expenses $ 37.3 Noncurrent Other liabilities 231.2 Total liabilities $ 268.5 As of September 30, 2019 the weighted-average remaining lease term was 7.9 years. Our lease agreements do not provide a readily determinable implicit rate nor is it available to us from our lessors. Instead, we estimate our incremental borrowing rate based on information available at lease commencement in order to discount lease payments to present value. The weighted-average discount rate of our operating leases was 5.9% , as of September 30, 2019 . Supplemental cash flow information related to our operating leases is as follows (in millions): Nine Months Ended September 30, 2019 Cash paid for operating leases $ 36.0 Leased assets obtained in exchange for new operating lease liabilities 22.9 Maturities of our operating lease liabilities are as follows (in millions): September 30, 2019 2019 (remaining) $ 13.2 2020 50.0 2021 49.3 2022 42.5 2023 37.9 2024 35.7 Thereafter 115.2 Total lease payments $ 343.8 Less: imputed interest $ 75.3 Present value of lease liabilities $ 268.5 The Company adopted ASU 2016-02 on January 1, 2019 as noted in Note 1 - Organization, Basis of Presentation and Significant Accounting Policies , and as required, the following disclosure is provided for periods prior to adoption. Annual non-cancellable minimum lease payments over the next five years and thereafter under ASC Topic 840 for the year ended December 31, 2018 were as follows (in millions): December 31, 2018 2019 $ 42.4 2020 44.4 2021 45.5 2022 41.9 2023 38.7 2024 and Thereafter 151.4 Total $ 364.3

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Our effective income tax rate on pre-tax income was 23.2% and 22.5% for the three and nine months ended September 30, 2019 , respectively, compared with 39.3% and 36.4% fo r the three and nine months ended September 30, 2018 , respectively. The year-over-year decrease was primarily driven by the one-year moratorium on the non-deductible ACA industry fee for 2019 and higher excess tax benefits resulting from the settlement of stock-compensation awards in 2019. There were no significant changes to unrecognized tax benefits for the three and nine months ended September 30, 2019 . Our unrecognized tax benefits are not expected to change significantly during the next 12 months.

DISCONTINUED OPERATIONS

DISCONTINUED OPERATIONS	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
DISCONTINUED OPERATIONS	DISCONTINUED OPERATIONS On August 3, 2016, our subsidiary, Universal American, completed the sale of its Traditional Insurance business prior to our acquisition of Universal American. This was accomplished by selling two life insurance subsidiaries, while retaining ownership of a third life insurance subsidiary, American Progressive Life & Health Insurance of New York ("Progressive"). The sale of the Traditional Insurance business underwritten by Progressive was accomplished through a 100% quota-share reinsurance treaty with a wholly-owned subsidiary of Nassau Re, that, when considered in combination with other reinsurance transactions previously entered into, resulted in the reinsurance of all of the Traditional Insurance policies that were underwritten by Progressive. Accordingly, the discontinued Traditional Insurance business did not materially affect our condensed consolidated statements of comprehensive income for any of the periods presented. In accordance with ASC 360-10, Property, Plant and Equipment and ASC 205-20, Presentation of Financial Statements—Discontinued Operations , the Traditional Insurance business has been reported in discontinued operations in this 2019 Form 10-Q. The following table summarizes the total assets and liabilities of our discontinued operations: September 30, 2019 December 31, 2018 (in millions) Assets Cash and cash equivalents $ 0.5 $ 0.1 Investments 49.9 42.8 Reinsurance recoverables 166.4 170.2 Other assets 0.5 0.5 Total Assets $ 217.3 $ 213.6 Liabilities Reserves and other policy liabilities $ 164.1 $ 166.9 Other liabilities 53.2 46.7 Total liabilities $ 217.3 $ 213.6 Progressive's traditional insurance products are reinsured under quota share coinsurance treaties with unaffiliated insurers, while the life insurance risks are reinsured under either quota share coinsurance or yearly-renewable term treaties with unaffiliated insurers. Under quota share coinsurance treaties, we pay the reinsurer an agreed upon percentage of all premiums and the reinsurer reimburses us that same percentage of any losses. In addition, the reinsurer pays us certain allowances to cover commissions, the cost of administering the policies and premium taxes. Under yearly-renewable term treaties, the reinsurer receives premiums at an agreed upon rate for its share of the risk on a yearly-renewable term basis. We also use excess of loss reinsurance agreements for certain policies whereby we limit our loss in excess of specified thresholds.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Indemnification Obligations Under Delaware law, our charter and bylaws and certain indemnification agreements to which we are a party, we are obligated to indemnify, or we have otherwise agreed to indemnify, certain of our current and former directors, officers and associates with respect to current and future investigations and litigation, including the matters discussed in this note. The indemnification agreements for our directors and executive officers with respect to events occurring prior to May 2009 require us to indemnify an indemnitee to the fullest extent permitted by law if the indemnitee was or is or becomes a party to or a witness or other participant in any proceeding by reason of any event or occurrence related to the indemnitee's status as a director, officer, associate, agent or fiduciary of the Company or any of our subsidiaries. The indemnification agreements require us to indemnify an indemnitee against all expenses, including attorney's fees, judgments, fines, settlement amounts and interest and other charges, and any taxes as a result of the receipt of payments under the indemnification agreement. We will not indemnify the indemnitee if not permitted under applicable law. We are required to advance all expenses incurred by the indemnitee. We are entitled to reimbursement by an indemnitee of expenses advanced if the indemnitee is not permitted to be reimbursed under applicable law after a final judicial determination is made and all rights of appeal have been exhausted or lapsed. We amended and restated our indemnification agreements in May 2009. The revised agreements apply to our officers and directors with respect to events occurring after that time. Pursuant to the 2009 indemnification agreements, we will indemnify the indemnitee against all expenses, including attorney's fees, judgments, penalties, fines, settlement amounts and any taxes imposed as a result of payments made under the indemnification agreement incurred in connection with any proceedings that relate to the indemnitee's status as a director, officer or associate of the Company or any of our subsidiaries or any other enterprise that the indemnitee was serving at our request. We will also indemnify for expenses incurred by an indemnitee if the indemnitee, by reason of his or her corporate status, is a witness in any proceeding. Further, we are required to indemnify for expenses incurred by an indemnitee in defense of a proceeding to the extent the indemnitee has been successful on the merits or otherwise. Finally, if the indemnitee is involved in certain proceedings as a result of the indemnitee's corporate status, we are required to advance the indemnitee's reasonable expenses incurred in connection with such proceeding, subject to the requirement that the indemnitee repay the expenses if it is ultimately determined that the indemnitee is not entitled to be indemnified. We are not obligated to indemnify an indemnitee for losses incurred in connection with any proceeding if a determination has not been made by the Board of Directors, a committee of disinterested directors or independent legal counsel in the specific case that the indemnitee has satisfied any standards of conduct required as a condition to indemnification under Section 145 of the Delaware General Corporation Law. Pursuant to our obligations, we have advanced legal fees and related expenses to three former officers and two additional associates who were criminally indicted in connection with the government investigations of the Company that commenced in 2007 related to federal criminal health care fraud charges including conspiracy to defraud the United States, false statements relating to health care matters, and health care fraud in connection with their defense of criminal charges. In June 2013, the jury in the federal criminal trial reached guilty verdicts on multiple charges for the four individuals that were tried in 2013. In May 2014, the individuals were sentenced and our request for restitution was denied. All four individuals filed notices of appeal and the government filed notices of cross appeal on three of the four individuals, which the government has subsequently voluntarily dismissed. The appellate court affirmed the convictions in August 2016. Mr. Farha filed a petition for a writ of certiorari to the United States Supreme Court in January 2017. In April 2017, the United States Supreme Court declined to hear the appeal by Mr. Farha. The fifth individual, Mr. Bereday, entered a guilty plea in June 2017 in connection with the federal criminal charges, which was accepted by the court in July 2017. Mr. Bereday was sentenced in November 2017. We have also previously advanced legal fees and related expenses to these five individuals regarding: a dispute in Delaware Chancery Court related to whether we were legally obligated to advance fees or indemnify certain of these individuals; the class actions titled Eastwood Enterprises, L.L.C. v. Farha, et al . and Hutton v. WellCare Health Plans, Inc. et al . filed in federal court; six stockholder derivative actions filed in federal and state courts between October 2007 and January 2008; an investigation by the United States Securities & Exchange Commission (the "Commission"); an action by the Commission filed in January 2012 against three of the five individuals, Messrs. Farha, Behrens and Bereday, and a qui tam action against Messrs. Farha, Behrens and Bereday in federal court. We settled the class actions in May 2011. In 2010, we settled the stockholder derivative actions and we were realigned as the plaintiff to pursue our claims against Messrs. Farha, Behrens and Bereday. Pursuant to the settlement agreements described below, Messrs. Farha, Behrens and Bereday were dismissed from the federal court and state derivative actions. Pursuant to the settlement agreement with Mr. Bereday described below, Mr. Bereday was dismissed from the fee advancement case in Delaware Chancery Court. The Commission action was closed in May 2018. The qui tam action is currently stayed and the stay is subject to being lifted at any time. In April 2017, the Commission and Mr. Farha entered into a consent judgment to pay $12.5 million to the Commission and $7.5 million to us. In April 2017, the Commission and Mr. Behrens also entered into a consent judgment to pay $4.5 million to the Commission and $1.5 million to us. In May 2018, the Commission and Mr. Bereday entered into a consent judgment to pay $4.5 million to the Commission and the case was closed. In addition, we have advanced a portion of the legal fees and related expenses to Mr. Farha in connection with lawsuits he filed in Delaware and Florida state court to have certain restrictions lifted on WellCare stock purportedly awarded to him during his employment with us. The Delaware and Florida state court matters have been dismissed. In September 2016, we entered into a settlement agreement with Mr. Farha pursuant to which he paid us $7.5 million , as referenced in the April 2017 consent judgment with the Commission, and we agreed that we would not seek to recover additional legal fees previously advanced related to these matters, and that our obligation to continue advancing fees would be limited to no more than an additional $7.5 million . We also have advanced a portion of the legal fees and related expenses to Mr. Behrens in connection with his lawsuit in Delaware state court to have certain restrictions lifted on WellCare stock purportedly awarded to him during his employment with WellCare, which the court dismissed. In October 2016, we also entered into a settlement agreement with Mr. Behrens pursuant to which he paid us $1.5 million , as referenced in the April 2017 consent judgment with the Commission, and we agreed that we would not seek to recover additional legal fees previously advanced in connection with these matters, and that our obligation to continue advancing fees would be limited to no more than an additional $1.5 million . In June 2017, we entered into a settlement agreement with Mr. Bereday that became effective in July 2017, pursuant to which we agreed that we would not seek to recover legal fees previously advanced in connection with these matters, and that our obligation to continue advancing fees would be limited to no more than an additional $2.5 million . In connection with these matters, we have advanced to the five individuals legal fees and related expenses from the inception of the investigations through September 30, 2019 , the cumulative amounts of which has not changed materially from December 31, 2018. We expense these costs as incurred and classify the costs as SG&A expense incurred in connection with the investigations and related matters. We have exhausted our insurance policies related to reimbursement of our advancement of fees related to these matters. We are unable to estimate the total amount of these costs or a range of possible loss. Accordingly, we continue to expense these costs as incurred. Proceedings Related to the Centene Transaction Between May 7 and May 9, 2019, three putative class action lawsuits were filed by purported stockholders of WellCare against WellCare and members of the WellCare Board in the United States District Court for the District of Delaware (Stein v. WellCare Health Plans, Inc., et al., Case No. 1:19-cv-00855-LPS (“Stein v. WellCare”); Kent v. WellCare Health Plans, Inc., et al., Case No. 1:19-cv-00865-LPS (“Kent v. WellCare”); and Clarke v. WellCare Health Plans, Inc., et al., Case No. 1:19-cv-00873-LPS “Clark v. WellCare”). The complaint in Kent v. WellCare also names Centene, Merger Sub I and Merger Sub II as defendants. The complaints in Stein v. WellCare, Kent v. WellCare and Clark v. WellCare purport to assert claims under Sections 14(a) and 20(a) of the Securities Exchange Act of 1934 and allege that the Joint Proxy Statement filed with the SEC on May 23, 2019 contained certain material omissions. In addition, on May 10, 2019, a putative class action lawsuit was filed by a purported stockholder of WellCare against WellCare, members of the WellCare Board, Centene, Merger Sub 1 and Merger Sub 2 in the Circuit Court of the 13th Judicial Circuit in and for Hillsborough County, Florida (Seabaugh v. WellCare Health Plans, Inc., et al., Case No. 2019CA004942 (“Seabaugh v. WellCare” and, together with Stein v. WellCare, Kent v. WellCare and Clark v. WellCare, the “Lawsuits”). The complaint in Seabaugh v. WellCare alleges that members of the WellCare Board breached their fiduciary duties by, among other things, agreeing to an allegedly unfair and inadequate price, agreeing to deal protection devices that allegedly impede their ability to investigate or obtain higher offers, allegedly failing to protect against certain purported conflicts of interest, and allegedly failing to disclose material information in the Joint Proxy Statement. The complaint further alleges that WellCare, Centene, Merger Sub 1 and Merger Sub 2 aided and abetted these alleged breaches of fiduciary duties. The complaint seeks to enjoin or rescind the mergers and requests an award of attorneys’ fees and damages in an unspecified amount. On July 1, 2019, the plaintiffs in Stein v. WellCare and Kent v. WellCare filed notices of voluntary dismissal. On September 24, 2019, the plaintiff in Clark v. WellCare filed a notice of voluntary dismissal. On October 8, 2019, the plaintiff in Seabaugh v. WellCare filed a notice of voluntary dismissal. Additional lawsuits arising out of or relating to the Merger Agreement, the Proxy Statement and/or the Centene Transaction may be filed in the future. WellCare intends to vigorously defend against any lawsuits challenging the merger. However, there can be no assurance that defendants will be successful in the outcome of any potential future lawsuits. One of the conditions to completion of the Centene Transaction is the absence of any applicable injunction or other order being in effect that prohibits completion of the Centene Transaction. Accordingly, if a plaintiff is successful in obtaining an injunction prohibiting completion of the Centene Transaction, then that injunction may delay or prevent the Centene Transaction from being completed, or from being completed within the expected timeframe. Other Lawsuits and Claims Based on the nature of our business, we are subject to regulatory reviews or other investigations by various state insurance and health care regulatory authorities and other state and federal regulatory authorities. These authorities regularly scrutinize the business practices of health insurance and benefits companies and their reviews focus on numerous facets of our business, including claims payment practices, provider contracting, competitive practices, commission payments, privacy issues and utilization management practices, among others. Some of these reviews have historically resulted in fines imposed on us and some have required changes to our business practices. We continue to be subject to such reviews, which may result in additional fines and/or sanctions being imposed, premium refunds or additional changes in our business practices. Separate and apart from the legal matters described above, we are also involved in other legal actions in the normal course of our business, including, without limitation, protests and appeals related to Medicaid procurement awards, wage and hour claims and other employment claims, claims for indemnification under purchase agreements, vendor disputes and provider disputes regarding payment of claims. Some of these actions seek monetary damages including claims for liquidated or punitive damages, which are not covered by insurance. We review relevant information with respect to these litigation matters and we update our estimates of reasonably possible losses and related disclosures. We accrue an estimate for contingent liabilities, including attorney's fees related to these matters, if a loss is probable and estimable. Currently, we do not expect that the resolution of any of these currently pending actions, either individually or in the aggregate, will differ materially from our current estimates or have a material adverse effect on our results of operations, financial condition and cash flows. However, the outcome of any legal actions cannot be predicted, and therefore actual results may differ from those estimates.

ORGANIZATION, BASIS OF PRESEN_2

ORGANIZATION, BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Use of Estimates	In the opinion of management, the unaudited condensed consolidated interim financial statements reflect all normal recurring adjustments that we consider necessary for the fair presentation of our financial position, results of operations and cash flows for the interim periods presented. In accordance with GAAP, we make certain estimates and assumptions that affect the amounts reported in the condensed consolidated interim financial statements and accompanying notes. We base these estimates, including assumptions as to the annualized tax rate, on our knowledge of current events and anticipated future events and evaluate and update our assumptions and estimates on an ongoing basis; however, actual results may differ from our estimates. We evaluated all material events subsequent to the date of these unaudited condensed consolidated interim financial statements.
Reclassifications	Certain reclassifications were made to 2018 financial information to conform to the 2019 presentation.
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated balance sheets and statements of comprehensive income, changes in stockholders' equity, and cash flows include our accounts and the accounts of our subsidiaries over which we have control or are the primary beneficiary. We eliminated all intercompany accounts and transactions. The accompanying unaudited condensed consolidated interim financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America ("GAAP"). Accordingly, certain financial information and footnote disclosures normally included in financial statements prepared in accordance with GAAP, but that are not required for interim reporting purposes, have been condensed or omitted. The accompanying unaudited condensed consolidated interim financial statements should be read in conjunction with the consolidated financial statements and notes thereto, for the fiscal year ended December 31, 2018 , included in our Annual Report on Form 10-K ("2018 Form 10-K"), which was filed with the U.S. Securities and Exchange Commission ("SEC") in February 2019. Results for the interim periods presented are not necessarily indicative of results that may be expected for the entire year or any other interim period. In the opinion of management, the unaudited condensed consolidated interim financial statements reflect all normal recurring adjustments that we consider necessary for the fair presentation of our financial position, results of operations and cash flows for the interim periods presented. In accordance with GAAP, we make certain estimates and assumptions that affect the amounts reported in the condensed consolidated interim financial statements and accompanying notes. We base these estimates, including assumptions as to the annualized tax rate, on our knowledge of current events and anticipated future events and evaluate and update our assumptions and estimates on an ongoing basis; however, actual results may differ from our estimates. We evaluated all material events subsequent to the date of these unaudited condensed consolidated interim financial statements. Certain reclassifications were made to 2018 financial information to conform to the 2019 presentation. Pharmacy Benefit Manager
Aetna Part D Membership Reinsurance	Aetna Part D Membership Reinsurance
Unconsolidated Subsidiaries	Unconsolidated Subsidiaries We work with physicians and other health care professionals to operate Accountable Care Organizations ("ACOs") under the Medicare Shared Saving Program ("MSSP") and Next Generation ACO Models. ACOs were established by the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010 (collectively, the "ACA") to reward integrated, efficient care and allow providers to share in any savings they achieve as a result of improved quality and operational efficiency. These ACOs are generally formed as limited liability companies. The ACOs are considered variable interest entities ("VIEs") under GAAP as these entities do not have sufficient equity to finance their own operations without additional financial support. We own a majority interest in our ACOs; however, we share the power to direct the activities that most significantly affect the ACOs with health care providers that are minority owners in the ACOs. This power is shared pursuant to the structure of the management committee of each of the ACOs. Accordingly, we have determined that we are not the primary beneficiary of the ACOs; therefore, we cannot consolidate their results. We perform an ongoing qualitative assessment of our variable interests in VIEs to determine whether we have a controlling financial interest and would therefore be considered the primary beneficiary of the VIE. We account for our participation in the ACOs using the equity method. Gains and losses are immaterial and are reported on the face of our condensed consolidated statements of comprehensive income as equity in earnings (losses) of unconsolidated subsidiaries.
Premium Receivable and Unearned Premiums	Premium Receivables and Unearned Premiums We record premiums earned but not received as premiums receivable and record premiums received in advance of the period of service as unearned premiums in our condensed consolidated balance sheets. A complete discussion of premiums receivable and unearned premiums is included in Note 2 - Summary of Significant Accounting Policies to the consolidated financial statements included in our 2018 Form 10-K. The premium receivable balance at September 30, 2019 is primarily related to Medicaid contracts with our state partners of approximately $1.2 billion , as well as net risk-adjusted premiums receivable under our MA and PDP contracts of approximately $186.7 million . Medicaid Risk-Adjusted Premiums and Retroactive Rate Changes As discussed further in Note 2 - Summary of Significant Accounting Policies
Medicare Part D Settlements	Medicare Part D Settlements We receive certain Part D prospective subsidy payments from the Centers for Medicare & Medicaid Services ("CMS") for our MA and PDP members as a fixed monthly per member amount, based on the estimated costs of providing prescription drug benefits over the plan year, as reflected in our bids. A discussion of the subsidy components under Part D is included in Note 2 - Summary of Significant Accounting Policies to the consolidated financial statements included in our 2018 Form 10-K. CMS will fully reimburse these subsidies, or recoup overpaid subsidies made during the plan year, as part of its annual settlement process that typically occurs in the fourth quarter of the subsequent year and, accordingly, there is no insurance risk to us. Therefore, amounts received for these subsidies are not considered premium revenue, and are reported, net of the subsidy benefits paid, as funds receivable (payable) for the benefit of members in the condensed consolidated balance sheets. As of December 31, 2018 , our condensed consolidated balance sheet primarily includes CMS Part D payables for the 2018 plan year. Our condensed consolidated balance sheet as of September 30, 2019 primarily includes a payable for the 2019 and 2018 plan years. We expect to settle a majority of the 2018 net payable during the remainder of 2019.
ACA Industry Fee	ACA Industry Fee
Accounting Standards Recently Adopted and Pending Adoption	Recently Adopted Accounting Standards In June 2018, the Financial Accounting Standards Board ("FASB") issued Accounting Standard Update ("ASU") 2018-07, “ Compensation-Stock Compensation (Topic 718) - Improvements to Nonemployee Share-Based Payment Accounting .” This update expands the scope of Topic 718, which currently only includes share-based payments issued to employees, to include share-based payments issued to non-employees for goods and services. This guidance was effective for interim and annual periods beginning after December 15, 2018. We adopted this guidance on January 1, 2019. The adoption of this guidance did not have a material effect on our consolidated results of operations, financial condition or cash flows. In February 2018, the FASB issued ASU 2018-02 " Income Statement – Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income ", which allows entities to reclassify stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 from accumulated other comprehensive income to retained earnings. The guidance is effective for interim and annual periods beginning after December 15, 2018. We adopted this guidance prospectively on January 1, 2019. The adoption of this guidance did not have a material effect on our consolidated results of operations, financial condition or cash flows. In March 2017, the FASB issued ASU No. 2017-08, " Receivables—Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities ". This update shortens the amortization period for the premium on certain purchased callable debt securities to the earliest call date. Previously, entities generally amortize the premium as a yield adjustment over the contractual life of the security. The new guidance does not change the accounting for purchased callable debt securities held at a discount. This guidance is effective for interim and annual periods beginning after December 15, 2018. We adopted this guidance on January 1, 2019 on a modified retrospective basis. The adoption of this guidance did not have a material effect on our consolidated results of operations, financial condition or cash flows. In February 2016, the FASB issued ASU 2016-02, “ Leases (Topic 842) ”, which for operating leases, requires a lessee to recognize a right-of-use asset and a lease liability, initially measured at the present value of the lease payments in its balance sheet. This standard also requires a lessee to recognize a single lease cost, calculated so that the cost of the lease is allocated over the lease term, on a generally straight-line basis. Subsequently, in July 2018, the FASB issued ASU 2018-11, “ Leases (Topic 842), Targeted Improvements ” which, among other things, allows companies to elect an optional transition method to apply the new lease standard through a cumulative-effect adjustment, if any, in the period of adoption, rather than in the earliest period presented. We adopted the standard on January 1, 2019 using the optional transition method. We elected the practical expedients permitted under the transition guidance, which allows us to carryforward our historical lease classifications for existing leases. Additionally, we elected the practical expedient to not separate non-lease components from the associated lease component. As part of the adoption process, we implemented a new lease accounting system. The adoption of this guidance resulted in the initial recognition of operating lease right-of-use assets of approximately $259.5 million , operating lease liabilities of approximately $277.3 million and the elimination of $17.8 million of straight-line lease liabilities, as of January 1, 2019. This guidance did not have a material effect on our consolidated results of operations or cash flows. Accounting Standards Pending Adoption In August 2018, the FASB issued ASU 2018-15, " Intangibles-Goodwill and Other-Internal-Use Software: Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract", which requires implementation costs incurred by customers in cloud computing arrangements (i.e., hosting arrangements) to be capitalized under the same premises of authoritative guidance for internal-use software, and deferred over the noncancellable term of the cloud computing arrangements plus any option renewal periods that are reasonably certain to be exercised by the customer or for which the exercise is controlled by the service provider. The guidance is effective for interim and annual periods beginning after December 15, 2019, with early adoption permitted. We are currently assessing the effect this guidance will have on our consolidated results of operations, financial condition or cash flows. In June 2016, the FASB issued ASU 2016-13, " Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, " which requires entities to use a current expected credit loss model, which is a new impairment model based on expected losses rather than incurred losses. Under this model, an entity would recognize an impairment allowance equal to its current estimate of all contractual cash flows that the entity does not expect to collect from financial assets measured at amortized cost. The entity's estimate would consider relevant information about past events, current conditions, and reasonable and supportable forecasts, which will result in recognition of lifetime expected credit losses upon loan origination. ASU 2016-13 is effective for interim and annual reporting periods beginning after December 15, 2019, with early adoption permitted for annual reporting periods beginning after December 15, 2018. We are currently assessing the effect this guidance will have on our consolidated results of operations, financial condition or cash flows.

CENTENE PLAN OF MERGER AND ACQU

CENTENE PLAN OF MERGER AND ACQUISITIONS (Tables)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Fair Values of Assets Acquired and Liabilities Assumed	The following table summarizes the final fair values of major classes of assets acquired and liabilities assumed at the Effective Date, based on our valuation assumptions, reconciled to the total consideration transferred. Assets (in millions) Cash, cash equivalents and restricted cash $ 484.4 Investments, including restricted investments 180.4 Premiums receivable, net 379.6 Other current assets 139.2 Property, equipment and capitalized software, net 49.3 Goodwill 1,598.2 Other intangible assets, net 543.5 Fair value of total assets acquired $ 3,374.6 Liabilities Medical benefits payable $ 534.3 ACA Fee liability 66.5 Other liabilities 253.7 Fair value of liabilities assumed 854.5 Fair value of net assets acquired $ 2,520.1
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination	The following table summarizes the final fair values and weighted average useful lives for identifiable intangible assets acquired in the Meridian acquisition as of the Effective Date of the acquisition. Gross Fair Value (in millions) Weighted Average Useful Life (in years) Membership $ 326.8 8.2 Tradenames 113.8 4.9 Provider network 8.3 15.0 Technology and other 94.6 5.8 Total $ 543.5 7.2
Final Fair Values and Weighted Average Useful Lives for Identifiable Intangible Assets Acquired	A summary of changes in our goodwill, including the allocation of Meridian goodwill, by reportable segment is as follows for the nine months ended September 30, 2019 : Medicaid Health Plans Medicare Health Plans Corporate and Other Not Assigned Total Balance as of December 31, 2018 $ 274.7 $ 392.3 $ — $ 1,560.7 $ 2,227.7 Acquisition related adjustments 1,416.3 119.0 62.9 (1,560.7 ) 37.5 Balance as of September 30, 2019 $ 1,691.0 $ 511.3 $ 62.9 $ — $ 2,265.2
Unaudited Pro Forma Results	The following unaudited pro forma results have been prepared for comparative purposes only and do not purport to be indicative of the results of operations that would have occurred had the acquisition actually consummated at January 1, 2018, or project the future results of the combined company. Pro Forma - Unaudited (in millions, except per share data) Three Months Ended Nine Months Ended Total revenues $ 5,869.8 $ 17,337.8 Net income $ 106.9 $ 355.2 Earnings per common share: Basic $ 2.14 $ 7.12 Diluted $ 2.11 $ 7.03 Weighted average common shares outstanding: Basic 49,976,863 49,949,219 Diluted 50,648,578 50,514,031

SEGMENT REPORTING (Tables)

SEGMENT REPORTING (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Revenue by Geographic Location	These states and the respective Medicaid premium revenue as a percentage of total consolidated premium revenue are as follows: For the Three Months Ended For the Nine Months Ended 2019 2018 2019 2018 Florida 20% 13% 19% 13% Illinois 13% * 13% * Kentucky 10% 13% 10% 14% *Our Illinois Medicaid health plan accounted for less than 10% of our consolidated premium revenue for the three and nine months ended September 30, 2018.
Segment Results	A summary of financial information for our reportable segments through the gross margin level and reconciliation to income from operations is presented in the table below. Medicaid Health Plan Medicare Health Plan Medicare PDP Corporate & Other Consolidated For the Three Months Ended September 30, 2019 (in millions) Premium $ 4,877.5 $ 1,841.4 $ 241.2 $ 5.5 $ 6,965.6 Products and services — — — 132.1 132.1 Total premium and products and services revenues 4,877.5 1,841.4 241.2 137.6 7,097.7 Medical benefits 4,308.7 1,533.5 182.7 0.8 6,025.7 Costs of products and services — — — 128.9 128.9 ACA industry fee — — — — — Medicaid premium taxes 35.6 — — — 35.6 Total gross margin expenses 4,344.3 1,533.5 182.7 129.7 6,190.2 Gross margin 533.2 307.9 58.5 7.9 907.5 Investment and other income — — — 42.5 42.5 Other expenses — — — (656.7 ) (656.7 ) Income from operations $ 533.2 $ 307.9 $ 58.5 $ (606.3 ) $ 293.3 For the Three Months Ended September 30, 2018 Premium $ 3,223.3 $ 1,582.0 $ 182.3 $ 1.2 $ 4,988.8 Products and services — — — 34.6 34.6 Total premium and products and services revenues 3,223.3 1,582.0 182.3 35.8 5,023.4 Medical benefits 2,738.1 1,340.8 115.1 1.0 4,195.0 Costs of products and services — — — 33.5 33.5 ACA industry fee 54.4 27.5 4.6 — 86.5 Medicaid premium taxes 31.5 — — — 31.5 Total gross margin expenses 2,824.0 1,368.3 119.7 34.5 4,346.5 Gross margin 399.3 213.7 62.6 1.3 676.9 Investment and other income — — — 34.7 34.7 Other expenses — — — (503.0 ) (503.0 ) Income from operations $ 399.3 $ 213.7 $ 62.6 $ (467.0 ) $ 208.6 Medicaid Health Plan Medicare Health Plan Medicare PDP Corporate & Other Consolidated For the Nine Months Ended September 30, 2019 (in millions) Premium $ 14,055.8 $ 5,557.3 $ 789.3 $ 14.8 $ 20,417.2 Products and services — — — 374.6 374.6 Total premium and products and services revenues 14,055.8 5,557.3 789.3 389.4 20,791.8 Medical benefits 12,599.5 4,627.2 651.7 6.1 17,884.5 Costs of products and services — — — 363.9 363.9 ACA industry fee — — — — — Medicaid premium taxes 99.0 — — — 99.0 Total gross margin expenses 12,698.5 4,627.2 651.7 370.0 18,347.4 Gross margin 1,357.3 930.1 137.6 19.4 2,444.4 Investment and other income — — — 120.7 120.7 Other expenses — — — (1,845.6 ) (1,845.6 ) Income from operations $ 1,357.3 $ 930.1 $ 137.6 $ (1,705.5 ) $ 719.5 For the Nine Months Ended September 30, 2018 Premium $ 8,899.4 $ 4,684.9 $ 642.2 $ 1.2 $ 14,227.7 Products and services — — — 34.6 34.6 Total premium and products and services revenues 8,899.4 4,684.9 642.2 35.8 14,262.3 Medical benefits 7,601.1 3,929.8 491.1 1.0 12,023.0 Costs of products and services — — — 33.5 33.5 ACA industry fee 151.5 81.8 13.7 — 247.0 Medicaid premium taxes 94.2 — — — 94.2 Total gross margin expenses 7,846.8 4,011.6 504.8 34.5 12,397.7 Gross margin 1,052.6 673.3 137.4 1.3 1,864.6 Investment and other income — — — 81.0 81.0 Other expenses — — — (1,341.9 ) (1,341.9 ) Income from operations $ 1,052.6 $ 673.3 $ 137.4 $ (1,259.6 ) $ 603.7

EQUITY AND EARNINGS PER SHARE (

EQUITY AND EARNINGS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Calculation of the Weighted-Average Common Shares Outstanding - Diluted	The calculation of the weighted-average common shares outstanding — diluted is as follows: For the Three Months Ended For the Nine Months Ended 2019 2018 2019 2018 Weighted-average common shares outstanding — basic 50,313,901 47,712,712 50,240,480 45,692,804 Dilutive effect of outstanding stock-based compensation awards 532,501 671,715 593,024 594,812 Weighted-average common shares outstanding — diluted 50,846,402 48,384,427 50,833,504 46,287,616 Anti-dilutive stock-based compensation awards excluded from computation 121,960 136,428 104,439 184,964

INVESTMENTS (Tables)

INVESTMENTS (Tables)	9 Months Ended
	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Short-term and Long-term Investments by Security Type	Excluding restricted cash, cash equivalents and investments, the amortized cost, gross unrealized gains or losses and estimated fair value of short-term and long-term investments by security type are summarized in the following tables. Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value September 30, 2019 Debt securities: Asset-backed securities $ 367.5 $ 1.3 $ (0.1 ) $ 368.7 Corporate debt securities 1,516.1 11.5 (1.3 ) 1,526.3 Municipal securities 154.6 3.2 (0.1 ) 157.7 Residential mortgage-backed securities 307.2 1.0 (0.4 ) 307.8 Short-term time deposits 137.2 — — 137.2 Government and agency obligations 26.4 — — 26.4 Other securities 149.2 0.8 (0.3 ) 149.7 Total debt securities 2,658.2 17.8 (2.2 ) 2,673.8 Equity securities (1) 468.5 — — 468.5 Total $ 3,126.7 $ 17.8 $ (2.2 ) $ 3,142.3 December 31, 2018 Asset-backed securities $ 144.7 $ — $ (0.5 ) $ 144.2 Corporate debt securities 943.0 0.5 (10.1 ) 933.4 Municipal securities 199.6 0.6 (0.9 ) 199.3 Residential mortgage-backed securities 7.2 — (0.2 ) 7.0 Short-term time deposits 242.2 — — 242.2 Government and agency obligations 44.9 — (0.1 ) 44.8 Other securities 72.5 — (0.1 ) 72.4 Total (1) $ 1,654.1 $ 1.1 $ (11.9 ) $ 1,643.3 (1) Investments in equity securities primarily consists of exchange traded funds in fixed income and preferred and hybrid securities. Equity securities were not material as of December 31, 2018.
Contractual Maturities of Available-for-sale Securities	Contractual maturities of debt securities at September 30, 2019 are as follows: Amortized Cost Fair Value Due in one year or less $ 952.4 $ 953.2 Due after one year through five years 676.7 682.6 Due after five years through ten years 221.4 227.8 Due after ten years 26.6 26.8 Asset-backed and mortgage-backed securities 781.1 783.4 Total $ 2,658.2 $ 2,673.8

RESTRICTED CASH, CASH EQUIVAL_2

RESTRICTED CASH, CASH EQUIVALENTS AND INVESTMENTS (Tables)	9 Months Ended
	Sep. 30, 2019
Restricted Investments Note [Abstract]
Schedule of Restricted Investments	The amortized cost, gross unrealized gains, gross unrealized losses and fair value of our restricted cash, cash equivalents and investment securities are as follows: Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value September 30, 2019 Cash $ 4.7 $ — $ — $ 4.7 Money market funds 121.6 — — 121.6 U.S. government securities and other 191.6 — — 191.6 Total $ 317.9 $ — $ — $ 317.9 December 31, 2018 Cash $ 11.3 $ — $ — $ 11.3 Money market funds 51.4 — — 51.4 U.S. government securities and other 172.5 — (0.5 ) 172.0 Total $ 235.2 $ — $ (0.5 ) $ 234.7

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Sep. 30, 2019
Share-based Payment Arrangement [Abstract]
Summary of Stock Unit Award Activity	A summary of RSU and PSU award activity, at target, for the nine months ended September 30, 2019 , is presented in the table below. For our PSUs, shares attained over target upon vesting are reflected as awards granted during the period, while shares canceled due to vesting below target are reflected as awards forfeited during the period. RSUs PSUs Total Outstanding as of January 1, 2019 253,235 606,708 859,943 Granted 113,276 352,683 465,959 Vested (126,103 ) (360,344 ) (486,447 ) Forfeited (13,959 ) (32,096 ) (46,055 ) Outstanding as of September 30, 2019 226,449 566,951 793,400

DEBT (Tables)

DEBT (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Outstanding Debt Obligations	The following table summarizes our outstanding debt obligations and their classification in the accompanying condensed consolidated balance sheets (in millions): September 30, 2019 December 31, 2018 Long-term debt, net: 5.25% Senior Notes, due April 1, 2025 $ 1,200.0 $ 1,200.0 5.375% Senior Notes, due August 15, 2026 750.0 750.0 Revolving Credit Facility 100.0 200.0 Debt issuance costs (20.9 ) (23.6 ) Total long-term debt, net $ 2,029.1 $ 2,126.4

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	Assets and liabilities measured at fair value on a recurring basis at September 30, 2019 are as follows: Fair Value Measurements Using Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investments: Debt securities: Asset-backed securities $ 368.7 $ — $ 368.7 $ — Corporate debt securities 1,526.3 — 1,526.3 — Municipal securities 157.7 — 157.7 — Residential mortgage-backed securities 307.8 — 307.8 — Short-term time deposits 137.2 — 137.2 — Government and agency obligations 26.4 26.4 — — Other securities 149.7 42.9 106.8 — Total debt securities 2,673.8 69.3 2,604.5 — Equity securities (1) 468.5 466.4 2.1 — Total investments $ 3,142.3 $ 535.7 $ 2,606.6 $ — Restricted cash, cash equivalents and investments: Cash $ 4.7 $ 4.7 $ — $ — Money market funds 121.6 121.6 — — U.S. government securities and other 191.6 191.4 0.2 — Total restricted cash, cash equivalents and investments $ 317.9 $ 317.7 $ 0.2 $ — (1) Investments in equity securities primarily consists of exchange traded funds in fixed-income and preferred and hybrid securities.
Assets and Liabilities Measured at Fair Value on a Recurring Basis	Assets and liabilities measured at fair value on a recurring basis at December 31, 2018 are as follows: Fair Value Measurements Using Carrying Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Investments: Asset-backed securities $ 144.2 $ — $ 144.2 $ — Corporate debt securities 933.4 — 933.4 — Municipal securities 199.3 — 199.3 — Residential mortgage-backed securities 7.0 — 7.0 — Short-term time deposits 242.2 — 242.2 — Government and agency obligations 44.8 44.8 — — Other securities 72.4 49.8 22.6 — Total Investments (1) $ 1,643.3 $ 94.6 $ 1,548.7 $ — Restricted cash, cash equivalents and investments: Cash $ 11.3 $ 11.3 $ — $ — Money market funds 51.4 51.4 — — U.S. government securities and other 172.0 171.8 0.2 — Total restricted cash, cash equivalents and investments $ 234.7 $ 234.5 $ 0.2 $ — (1) Equity securities were not material as of December 31, 2018.
Carrying Value and Fair Value of Long-term Debt	The following table presents the carrying value and fair value of our long-term debt outstanding as of September 30, 2019 and December 31, 2018 : Fair Value Measurements Using Carrying Value Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Long-term debt - September 30, 2019 2,029.1 2,054.4 100.0 — Long-term debt - December 31, 2018 2,126.4 1,885.2 200.0 —

MEDICAL BENEFITS PAYABLE (Table

MEDICAL BENEFITS PAYABLE (Tables)	9 Months Ended
	Sep. 30, 2019
MEDICAL BENEFITS PAYABLE [Abstract]
Reconciliation of the Beginning and Ending Balances of Medical Benefits Payable, by Segment	A reconciliation of the beginning and ending balances of medical benefits payable, by segment, is as follows: For the Nine Months Ended September 30, 2019 Medicaid Health Plans Medicare Health Plans Medicare PDPs Corporate and Other (2) Consolidated Beginning balance (1) $ 2,012.8 $ 823.5 $ 59.1 $ 2.0 $ 2,897.4 Acquisitions — — — — — Medical benefits incurred related to: Current year 12,885.1 4,732.1 700.2 7.2 18,324.6 Prior years (285.6 ) (104.9 ) (48.5 ) (1.1 ) (440.1 ) Total 12,599.5 4,627.2 651.7 6.1 17,884.5 Medical benefits paid related to: Current year (10,936.0 ) (3,858.4 ) (628.4 ) (5.5 ) (15,428.3 ) Prior years (1,384.3 ) (600.7 ) (3.8 ) (0.9 ) (1,989.7 ) Total (12,320.3 ) (4,459.1 ) (632.2 ) (6.4 ) (17,418.0 ) Ending balance (1) $ 2,292.0 $ 991.6 $ 78.6 $ 1.7 $ 3,363.9 (1) The Medicaid Health Plans and Consolidated beginning balance for 2019 include a premium deficiency reserve for our Illinois Medicaid programs ("Illinois PDR"), which amounted to $16.1 million at December 31, 2018 . There was no Illinois PDR at September 30, 2019. See Note 2 - Summary of Significant Accounting Policies in our 2018 Form 10-K for further discussion. (2) The Corporate and Other category includes operating segments that are not individually reportable because they do not meet the quantitative thresholds required by generally accepted accounting principles. For the Nine Months Ended September 30, 2018 Medicaid Health Plans Medicare Health Plans Medicare PDPs Corporate and Other Consolidated Beginning balance (1) $ 1,373.2 $ 722.5 $ 50.6 $ — $ 2,146.3 Acquisitions 478.2 47.1 — 2.7 528.0 Medical benefits incurred related to: Current year 7,803.2 4,051.6 560.4 1.0 12,416.2 Prior years (202.1 ) (121.8 ) (69.3 ) — (393.2 ) Total 7,601.1 3,929.8 491.1 1.0 12,023.0 — Medical benefits paid related to: Current year (6,562.2 ) (3,382.3 ) (502.9 ) (0.8 ) (10,448.2 ) Prior years (889.3 ) (488.3 ) 30.0 (0.1 ) (1,347.7 ) Total (7,451.5 ) (3,870.6 ) (472.9 ) (0.9 ) (11,795.9 ) Ending balance (1) $ 2,001.0 $ 828.8 $ 68.8 $ 2.8 $ 2,901.4 (1) The Medicaid Health Plans and Consolidated beginning and ending balances for 2018 include a premium deficiency reserve for our Illinois Medicaid program ("Illinois PDR"), which amounted to $20.6 million and $45.6 million at September 30, 2018 and December 31, 2017, respectively.

LEASES (Tables)

LEASES (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Balance sheet information related to operating leases	Balance sheet information related to our operating leases was as follows (in millions): Classification September 30, 2019 Assets: Right of use assets Other assets $ 247.0 Liabilities: Current Accounts payable and accrued expenses $ 37.3 Noncurrent Other liabilities 231.2 Total liabilities $ 268.5
Supplemental cash flow information related to leases	Supplemental cash flow information related to our operating leases is as follows (in millions): Nine Months Ended September 30, 2019 Cash paid for operating leases $ 36.0 Leased assets obtained in exchange for new operating lease liabilities 22.9
Maturities of operating leases	Maturities of our operating lease liabilities are as follows (in millions): September 30, 2019 2019 (remaining) $ 13.2 2020 50.0 2021 49.3 2022 42.5 2023 37.9 2024 35.7 Thereafter 115.2 Total lease payments $ 343.8 Less: imputed interest $ 75.3 Present value of lease liabilities $ 268.5
Schedule of noncancelable minimum lease payments under ASC Topic 840	Annual non-cancellable minimum lease payments over the next five years and thereafter under ASC Topic 840 for the year ended December 31, 2018 were as follows (in millions): December 31, 2018 2019 $ 42.4 2020 44.4 2021 45.5 2022 41.9 2023 38.7 2024 and Thereafter 151.4 Total $ 364.3

DISCONTINUED OPERATIONS (Tables

DISCONTINUED OPERATIONS (Tables)	9 Months Ended
	Sep. 30, 2019
Discontinued Operations and Disposal Groups [Abstract]
Total Assets and Liabilities of Discontinued Operations	The following table summarizes the total assets and liabilities of our discontinued operations: September 30, 2019 December 31, 2018 (in millions) Assets Cash and cash equivalents $ 0.5 $ 0.1 Investments 49.9 42.8 Reinsurance recoverables 166.4 170.2 Other assets 0.5 0.5 Total Assets $ 217.3 $ 213.6 Liabilities Reserves and other policy liabilities $ 164.1 $ 166.9 Other liabilities 53.2 46.7 Total liabilities $ 217.3 $ 213.6

ORGANIZATION, BASIS OF PRESEN_3

ORGANIZATION, BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Details) member in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)member	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)member	Sep. 30, 2018USD ($)	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)
Funds Receivable/Payable for the Benefit of Members [Line Items]
Membership | member	6.4		6.4
Premiums revenue related to Aetna Part D Membership	$ 6,965,600,000	$ 4,988,800,000	$ 20,417,200,000	$ 14,227,700,000
Premiums receivable, net	1,447,500,000		1,447,500,000			$ 1,223,400,000
ACA industry fee	0	86,500,000	0	247,000,000
Medicaid ACA industry fee reimbursement revenue	0	71,500,000	0	199,000,000
ACA industry fee remitted		388,500,000		388,500,000
Right of use assets	247,000,000		247,000,000		$ 259,500,000
Present value of lease liabilities	268,500,000		268,500,000		277,300,000
Premiums receivable, net
Funds Receivable/Payable for the Benefit of Members [Line Items]
Medicaid retroactive rate change and risk score adjustments	277,900,000		277,900,000			54,400,000
Medicaid Health Plan | State Partners
Funds Receivable/Payable for the Benefit of Members [Line Items]
Premiums receivable, net	1,200,000,000		1,200,000,000
Medicare Advantage | Medicare Advantage and PDP
Funds Receivable/Payable for the Benefit of Members [Line Items]
Premiums receivable, net	186,700,000		186,700,000
Aetna Part D Business
Funds Receivable/Payable for the Benefit of Members [Line Items]
Reinsurance receivables related to premiums receivable	167,200,000		167,200,000
Reinsurance payable	549,400,000		549,400,000			0
Reinsurance recoverables	382,200,000		382,200,000			$ 0
Premiums revenue related to Aetna Part D Membership	364,400,000		1,300,000,000
Medical benefits ceded related to Aetna Part D membership	$ 224,200,000		$ 999,200,000
Accounting Standards Update 2016-02
Funds Receivable/Payable for the Benefit of Members [Line Items]
Elimination of straight-line lease liabilities					$ 17,800,000
Meridian
Funds Receivable/Payable for the Benefit of Members [Line Items]
ACA industry fee remitted		$ 66,500,000		$ 66,500,000

CENTENE PLAN OF MERGER, PROPO_2

CENTENE PLAN OF MERGER, PROPOSED DIVESTITURES AND COMPLETED ACQUISITIONS - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 01, 2018	Nov. 30, 2018	Aug. 31, 2018	Jun. 30, 2020	Sep. 30, 2019	Dec. 31, 2020	Dec. 31, 2018
Business Acquisition [Line Items]
Aggregate amount of capital expenses budgeted, percentage (more than)					110.00%
Goodwill					$ 2,265.2		$ 2,227.7
Senior Notes | 5.375% Senior Notes, due August 15, 2026
Business Acquisition [Line Items]
Interest rate			5.375%		5.375%
Aetna Part D Business
Business Acquisition [Line Items]
Acquisition consideration transferred		$ 115.8
Meridian
Business Acquisition [Line Items]
Acquisition consideration transferred	$ 2,500
Estimated weighted average useful live of identifiable intangible assets	7 years 2 months 12 days
Sale of stock, number of shares issued in transaction			5,207,547
Adjustment to intangible assets					$ 50.5
Adjustment to deferred tax liabilities					$ 22.9
Goodwill	$ 1,598.2
Net deferred tax liabilities acquired	$ 23.6
Meridian | Senior Notes | 5.375% Senior Notes, due August 15, 2026
Business Acquisition [Line Items]
Interest rate			5.375%
Forecast | Aetna Part D Business
Business Acquisition [Line Items]
Estimated weighted average useful live of identifiable intangible assets						8 years
Forecast | Centene
Business Acquisition [Line Items]
Cash received per share				$ 120
Shares received for each common share (in shares)				3.38

CENTENE PLAN OF MERGER, PROPO_3

CENTENE PLAN OF MERGER, PROPOSED DIVESTITURES AND COMPLETED ACQUISITIONS - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018	Sep. 01, 2018
Assets
Goodwill	$ 2,265.2	$ 2,227.7
Meridian
Assets
Cash, cash equivalents and restricted cash			$ 484.4
Investments, including restricted investments			180.4
Premiums receivable, net			379.6
Other current assets			139.2
Property, equipment and capitalized software, net			49.3
Goodwill			1,598.2
Other intangible assets, net			543.5
Fair value of total assets acquired			3,374.6
Liabilities
Medical benefits payable			534.3
ACA Fee liability			66.5
Other liabilities			253.7
Fair value of liabilities assumed			854.5
Fair value of net assets acquired			$ 2,520.1

CENTENE PLAN OF MERGER, PROPO_4

CENTENE PLAN OF MERGER, PROPOSED DIVESTITURES AND COMPLETED ACQUISITIONS - Identifiable Intangible Assets Acquired (Details) - Meridian $ in Millions	Sep. 01, 2018USD ($)
Business Acquisition [Line Items]
Gross Fair Value (in millions)	$ 543.5
Weighted Average Useful Life (in years)	7 years 2 months 12 days
Membership
Business Acquisition [Line Items]
Gross Fair Value (in millions)	$ 326.8
Weighted Average Useful Life (in years)	8 years 2 months 12 days
Tradenames
Business Acquisition [Line Items]
Gross Fair Value (in millions)	$ 113.8
Weighted Average Useful Life (in years)	4 years 10 months 24 days
Provider network
Business Acquisition [Line Items]
Gross Fair Value (in millions)	$ 8.3
Weighted Average Useful Life (in years)	15 years
Technology and other
Business Acquisition [Line Items]
Gross Fair Value (in millions)	$ 94.6
Weighted Average Useful Life (in years)	5 years 9 months 18 days

CENTENE PLAN OF MERGER, PROPO_5

CENTENE PLAN OF MERGER, PROPOSED DIVESTITURES AND COMPLETED ACQUISITIONS - Goodwill Acquired (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Changes in Goodwill
Beginning Balance	$ 2,227.7
Acquisition related adjustments	37.5
Ending Balance	2,265.2
Medicaid Health Plan
Changes in Goodwill
Beginning Balance	274.7
Acquisition related adjustments	1,416.3
Ending Balance	1,691
Medicare Health Plan
Changes in Goodwill
Beginning Balance	392.3
Acquisition related adjustments	119
Ending Balance	511.3
Not Assigned
Changes in Goodwill
Beginning Balance	1,560.7
Acquisition related adjustments	(1,560.7)
Ending Balance	0
Corporate, non-segment
Changes in Goodwill
Beginning Balance	0
Acquisition related adjustments	62.9
Ending Balance	$ 62.9

CENTENE PLAN OF MERGER, PROPO_6

CENTENE PLAN OF MERGER, PROPOSED DIVESTITURES AND COMPLETED ACQUISITIONS - Pro Forma Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Business Combinations [Abstract]
Total revenues	$ 5,869.8	$ 17,337.8
Net income	$ 106.9	$ 355.2
Earnings per common share:
Basic (in dollars per share)	$ 2.14	$ 7.12
Diluted (in dollars per share)	$ 2.11	$ 7.03
Weighted average common shares outstanding:
Basic (in shares)	49,976,863	49,949,219
Diluted (in shares)	50,648,578	50,514,031

SEGMENT REPORTING - Narrative (

SEGMENT REPORTING - Narrative (Details)	Dec. 01, 2018region	Sep. 30, 2019segment
Segment Reporting Information [Line Items]
Number of reportable segments | segment		3
Serious Mental Illness Specialty Plan | Florida | Medicaid Health Plan
Segment Reporting Information [Line Items]
Number of regions	10
Term Of agreement	5 years
Medical Services Managed Care Plan | Florida | Medicaid Health Plan
Segment Reporting Information [Line Items]
Number of regions	11

SEGMENT REPORTING - Revenue by

SEGMENT REPORTING - Revenue by Geographic Location (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Florida
Revenues from External Customers and Long-Lived Assets [Line Items]
Premium revenue as a percentage of total consolidated premium revenue	20.00%	13.00%	19.00%	13.00%
Illinois
Revenues from External Customers and Long-Lived Assets [Line Items]
Premium revenue as a percentage of total consolidated premium revenue	13.00%		13.00%
Kentucky
Revenues from External Customers and Long-Lived Assets [Line Items]
Premium revenue as a percentage of total consolidated premium revenue	10.00%	13.00%	10.00%	14.00%

SEGMENT REPORTING - Segment Res

SEGMENT REPORTING - Segment Results (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Premium	$ 6,965.6	$ 4,988.8	$ 20,417.2	$ 14,227.7
Products and services	132.1	34.6	374.6	34.6
Medical benefits	6,025.7	4,195	17,884.5	12,023
Costs of products and services	128.9	33.5	363.9	33.5
ACA industry fee	0	86.5	0	247
Investment and other income	42.5	34.7	120.7	81
Operating segments
Segment Reporting Information [Line Items]
Premium	6,965.6	4,988.8	20,417.2	14,227.7
Products and services	132.1	34.6	374.6	34.6
Total premium and products and services revenues	7,097.7	5,023.4	20,791.8	14,262.3
Medical benefits	6,025.7	4,195	17,884.5	12,023
Costs of products and services	128.9	33.5	363.9	33.5
ACA industry fee	0	86.5	0	247
Medicaid premium taxes	35.6	31.5	99	94.2
Total gross margin expenses	6,190.2	4,346.5	18,347.4	12,397.7
Gross margin	907.5	676.9	2,444.4	1,864.6
Investment and other income	42.5	34.7	120.7	81
Other expenses	(656.7)	(503)	(1,845.6)	(1,341.9)
Income from operations	293.3	208.6	719.5	603.7
Corporate, non-segment
Segment Reporting Information [Line Items]
Premium	5.5	1.2	14.8	1.2
Products and services	132.1	34.6	374.6	34.6
Total premium and products and services revenues	137.6	35.8	389.4	35.8
Medical benefits	0.8	1	6.1	1
Costs of products and services	128.9	33.5	363.9	33.5
ACA industry fee	0	0	0	0
Medicaid premium taxes	0	0	0	0
Total gross margin expenses	129.7	34.5	370	34.5
Gross margin	7.9	1.3	19.4	1.3
Investment and other income	42.5	34.7	120.7	81
Other expenses	(656.7)	(503)	(1,845.6)	(1,341.9)
Income from operations	(606.3)	(467)	(1,705.5)	(1,259.6)
Medicaid Health Plan | Operating segments
Segment Reporting Information [Line Items]
Premium	4,877.5	3,223.3	14,055.8	8,899.4
Products and services	0	0	0	0
Total premium and products and services revenues	4,877.5	3,223.3	14,055.8	8,899.4
Medical benefits	4,308.7	2,738.1	12,599.5	7,601.1
Costs of products and services	0	0	0	0
ACA industry fee	0	54.4	0	151.5
Medicaid premium taxes	35.6	31.5	99	94.2
Total gross margin expenses	4,344.3	2,824	12,698.5	7,846.8
Gross margin	533.2	399.3	1,357.3	1,052.6
Investment and other income	0	0	0	0
Other expenses	0	0	0	0
Income from operations	533.2	399.3	1,357.3	1,052.6
Medicare Health Plan | Operating segments
Segment Reporting Information [Line Items]
Premium	1,841.4	1,582	5,557.3	4,684.9
Products and services	0	0	0	0
Total premium and products and services revenues	1,841.4	1,582	5,557.3	4,684.9
Medical benefits	1,533.5	1,340.8	4,627.2	3,929.8
Costs of products and services	0	0	0	0
ACA industry fee	0	27.5	0	81.8
Medicaid premium taxes	0	0	0	0
Total gross margin expenses	1,533.5	1,368.3	4,627.2	4,011.6
Gross margin	307.9	213.7	930.1	673.3
Investment and other income	0	0	0	0
Other expenses	0	0	0	0
Income from operations	307.9	213.7	930.1	673.3
Medicare PDP | Operating segments
Segment Reporting Information [Line Items]
Premium	241.2	182.3	789.3	642.2
Products and services	0	0	0	0
Total premium and products and services revenues	241.2	182.3	789.3	642.2
Medical benefits	182.7	115.1	651.7	491.1
Costs of products and services	0	0	0	0
ACA industry fee	0	4.6	0	13.7
Medicaid premium taxes	0	0	0	0
Total gross margin expenses	182.7	119.7	651.7	504.8
Gross margin	58.5	62.6	137.6	137.4
Investment and other income	0	0	0	0
Other expenses	0	0	0	0
Income from operations	$ 58.5	$ 62.6	$ 137.6	$ 137.4

EQUITY AND EARNINGS PER SHARE-

EQUITY AND EARNINGS PER SHARE- Calculation of Weighted-Average Common Shares Outstanding (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Offering price per share	$ 265
Issuance of common stock, net of issuance costs	$ 1,300			$ 0	$ 1,342.3
Investment banking, advisory, brokerage, and underwriting fees and commissions	$ 37.7
Weighted-average common shares outstanding — basic (in shares)		50,313,901	47,712,712	50,240,480	45,692,804
Dilutive effect of outstanding stock-based compensation awards (in shares)		532,501	671,715	593,024	594,812
Weighted-average common shares outstanding — diluted (in shares)		50,846,402	48,384,427	50,833,504	46,287,616
Anti-dilutive stock-based compensation awards excluded from computation (in shares)		121,960	136,428	104,439	184,964
Meridian
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Sale of stock, number of shares issued in transaction	5,207,547

INVESTMENTS - Short-term and Lo

INVESTMENTS - Short-term and Long-term Investments by Security Type (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Debt securities:
Amortized Cost	$ 2,658.2	$ 1,654.1
Gross Unrealized Gains	17.8	1.1
Gross Unrealized Losses	(2.2)	(11.9)
Estimated Fair Value	2,673.8	1,643.3
Equity securities
Amortized Cost	468.5
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Estimated Fair Value	468.5
Total
Amortized Cost	3,126.7
Gross Unrealized Gains	17.8
Gross Unrealized Losses	(2.2)
Estimated Fair Value	3,142.3
Asset-backed securities
Debt securities:
Amortized Cost	367.5	144.7
Gross Unrealized Gains	1.3	0
Gross Unrealized Losses	(0.1)	(0.5)
Estimated Fair Value	368.7	144.2
Corporate debt securities
Debt securities:
Amortized Cost	1,516.1	943
Gross Unrealized Gains	11.5	0.5
Gross Unrealized Losses	(1.3)	(10.1)
Estimated Fair Value	1,526.3	933.4
Municipal securities
Debt securities:
Amortized Cost	154.6	199.6
Gross Unrealized Gains	3.2	0.6
Gross Unrealized Losses	(0.1)	(0.9)
Estimated Fair Value	157.7	199.3
Residential mortgage-backed securities
Debt securities:
Amortized Cost	307.2	7.2
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(0.4)	(0.2)
Estimated Fair Value	307.8	7
Short-term time deposits
Debt securities:
Amortized Cost	137.2	242.2
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	137.2	242.2
Government and agency obligations
Debt securities:
Amortized Cost	26.4	44.9
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(0.1)
Estimated Fair Value	26.4	44.8
Other securities
Debt securities:
Amortized Cost	149.2	72.5
Gross Unrealized Gains	0.8	0
Gross Unrealized Losses	(0.3)	(0.1)
Estimated Fair Value	$ 149.7	$ 72.4

INVESTMENTS - Contractual Matur

INVESTMENTS - Contractual Maturities of Available-for-sale Securities (Details) $ in Millions	Sep. 30, 2019USD ($)
Amortized Cost
Due in one year or less	$ 952.4
Due after one year through five years	676.7
Due after five years through ten years	221.4
Due after ten years	26.6
Asset-backed and mortgage-backed securities	781.1
Total	2,658.2
Fair Value
Due in one year or less	953.2
Due after one year through five years	682.6
Due after five years through ten years	227.8
Due after ten years	26.8
Asset-backed and mortgage-backed securities	783.4
Total	$ 2,673.8

INVESTMENTS - Narrative (Detail

INVESTMENTS - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Debt securities, available-for-sale, percent investment grade securities	97.00%		97.00%
Proceeds from sale of available-for-sale investments	$ 1,400,000,000	$ 252,400,000	$ 2,800,000,000	$ 471,200,000
Realized gains and losses on sales and redemptions of investments	0	0	0	0
Other than temporary impairment losses	$ 0	$ 0	$ 0	$ 0

RESTRICTED CASH, CASH EQUIVAL_3

RESTRICTED CASH, CASH EQUIVALENTS AND INVESTMENTS - Schedule of Restricted Investments (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Restricted Cash and Cash Equivalents Items [Line Items]
Amortized Cost	$ 317.9	$ 235.2
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(0.5)
Estimated Fair Value	317.9	234.7
Cash
Restricted Cash and Cash Equivalents Items [Line Items]
Amortized Cost	4.7	11.3
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	4.7	11.3
Money market funds
Restricted Cash and Cash Equivalents Items [Line Items]
Amortized Cost	121.6	51.4
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	121.6	51.4
U.S. government securities and other
Restricted Cash and Cash Equivalents Items [Line Items]
Amortized Cost	191.6	172.5
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(0.5)
Estimated Fair Value	$ 191.6	$ 172

RESTRICTED CASH, CASH EQUIVAL_4

RESTRICTED CASH, CASH EQUIVALENTS AND INVESTMENTS - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restricted Investments Note [Abstract]
Realized gains (losses) on restricted investments	$ 0	$ 0	$ 0	$ 0

STOCK-BASED COMPENSATION - Narr

STOCK-BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense	$ 17.1	$ 21.4	$ 58.9	$ 51.5
Unrecognized compensation cost	$ 89.4		$ 89.4
Weighted-average period over which compensation costs are expected to be recognized			1 year 8 months 12 days
Closing common stock price (in USD per share)	$ 259.17		$ 259.17
Grants in period, weighted average grant date fair value (in USD per share)			$ 308.55
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 23.7		$ 23.7
The 2019 Incentive Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common shares available for issuance (in shares)	1.6		1.6

STOCK-BASED COMPENSATION - Summ

STOCK-BASED COMPENSATION - Summary of Stock Unit Award Activity (Details)	9 Months Ended
	Sep. 30, 2019shares
Equity Instruments Other than Options [Roll Forward]
Outstanding as of beginning of period (in shares)	859,943
Granted (in shares)	465,959
Vested (in shares)	(486,447)
Forfeited (in shares)	(46,055)
Outstanding at end of period (in shares)	793,400
RSUs
Equity Instruments Other than Options [Roll Forward]
Outstanding as of beginning of period (in shares)	253,235
Granted (in shares)	113,276
Vested (in shares)	(126,103)
Forfeited (in shares)	(13,959)
Outstanding at end of period (in shares)	226,449
PSUs
Equity Instruments Other than Options [Roll Forward]
Outstanding as of beginning of period (in shares)	606,708
Granted (in shares)	352,683
Vested (in shares)	(360,344)
Forfeited (in shares)	(32,096)
Outstanding at end of period (in shares)	566,951

DEBT - Schedule of Outstanding

DEBT - Schedule of Outstanding Debt Obligations (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018	Aug. 31, 2018	Mar. 31, 2017
Long-term debt, net
Debt issuance costs	$ (20.9)	$ (23.6)
Total long-term debt, net	2,029.1	2,126.4
Revolving Credit Facility
Long-term debt, net
Revolving Credit Facility	100	200
Senior Notes | 5.25% Senior Notes, due April 1, 2025
Long-term debt, net
Senior notes	$ 1,200	1,200
Interest rate	5.25%			5.25%
Senior Notes | 5.375% Senior Notes, due August 15, 2026
Long-term debt, net
Senior notes	$ 750	$ 750
Interest rate	5.375%		5.375%

DEBT - Narrative (Details)

DEBT - Narrative (Details) - USD ($)	1 Months Ended	9 Months Ended
	Jul. 31, 2018	Sep. 30, 2019	Dec. 31, 2018	Aug. 31, 2018	Apr. 07, 2017	Mar. 31, 2017	Jan. 31, 2016
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 1,300,000,000						$ 1,000,000,000
Credit facility increase subject to certain conditions	$ 500,000,000
Net payments on revolving credit facility		$ 100,000,000
Borrowings outstanding		$ 100,000,000	$ 200,000,000
Senior Notes | 5.375% Senior Notes, due August 15, 2026
Debt Instrument [Line Items]
Interest rate		5.375%		5.375%
Aggregate principal amount				$ 750,000,000
Senior Notes | 5.25% Senior Notes, due April 1, 2025
Debt Instrument [Line Items]
Interest rate		5.25%				5.25%
Aggregate principal amount						$ 1,200,000,000
Senior Notes | 5.75% Senior Notes, due November 15, 2020
Debt Instrument [Line Items]
Interest rate					5.75%
Debt repurchase amount					$ 900,000,000
Minimum | Revolving Credit Facility
Debt Instrument [Line Items]
Commitment fee percentage on unused amount	0.20%
Maximum | Revolving Credit Facility
Debt Instrument [Line Items]
Commitment fee percentage on unused amount	0.30%

FAIR VALUE MEASUREMENTS - Asset

FAIR VALUE MEASUREMENTS - Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	$ 468.5
Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	317.9	$ 234.7
Fair value, measurements, recurring | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	368.7	144.2
Fair value, measurements, recurring | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	1,526.3	933.4
Fair value, measurements, recurring | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	157.7	199.3
Fair value, measurements, recurring | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	307.8	7
Fair value, measurements, recurring | Short-term time deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	137.2	242.2
Fair value, measurements, recurring | Government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	26.4	44.8
Fair value, measurements, recurring | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	149.7	72.4
Fair value, measurements, recurring | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	4.7	11.3
Fair value, measurements, recurring | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	121.6	51.4
Fair value, measurements, recurring | U.S. government securities and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	191.6	172
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	535.7	94.6
Equity securities	466.4
Restricted cash, cash equivalents and investments	317.7	234.5
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term time deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	26.4	44.8
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	42.9	49.8
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	4.7	11.3
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	121.6	51.4
Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government securities and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	191.4	171.8
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,606.6	1,548.7
Equity securities	2.1
Restricted cash, cash equivalents and investments	0.2	0.2
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	368.7	144.2
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	1,526.3	933.4
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	157.7	199.3
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	307.8	7
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | Short-term time deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	137.2	242.2
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | Government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	106.8	22.6
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	0	0
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	0	0
Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2) | U.S. government securities and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	0.2	0.2
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Equity securities	0
Restricted cash, cash equivalents and investments	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | Corporate debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | Residential mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | Short-term time deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | Government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | Other securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	0	0
Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3) | U.S. government securities and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Restricted cash, cash equivalents and investments	0	0
Carrying Value | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	3,142.3	$ 1,643.3
Debt Securities | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,673.8
Debt Securities | Fair value, measurements, recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	69.3
Debt Securities | Fair value, measurements, recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	2,604.5
Debt Securities | Fair value, measurements, recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	$ 0

FAIR VALUE MEASUREMENTS - Carry

FAIR VALUE MEASUREMENTS - Carrying Value and Fair Value of Long-term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Quoted Prices in Active Markets for Identical Assets (Level 1)
Debt Instrument [Line Items]
Long-term debt, fair value	$ 2,054.4	$ 1,885.2
Significant Other Observable Inputs (Level 2)
Debt Instrument [Line Items]
Long-term debt, fair value	100	200
Significant Unobservable Inputs (Level 3)
Debt Instrument [Line Items]
Long-term debt, fair value	0	0
Carrying Value
Debt Instrument [Line Items]
Long-term debt, fair value	$ 2,029.1	$ 2,126.4

MEDICAL BENEFITS PAYABLE - Reco

MEDICAL BENEFITS PAYABLE - Reconciliation of Beginning and Ending Balances, by Segment (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of the beginning and ending balance of medical benefits payable [Roll Forward]
Beginning balance	$ 2,897.4	$ 2,146.3
Acquisitions	0	528
Medical benefits incurred related to
Current year	18,324.6	12,416.2
Prior years	(440.1)	(393.2)
Total	17,884.5	12,023
Medical benefits paid related to
Current year	(15,428.3)	(10,448.2)
Prior years	(1,989.7)	(1,347.7)
Total	(17,418)	(11,795.9)
Ending balance	3,363.9	2,901.4
Premium deficiency reserve	0	20.6	$ 16.1	$ 45.6
Medicaid Health Plans
Reconciliation of the beginning and ending balance of medical benefits payable [Roll Forward]
Beginning balance	2,012.8	1,373.2
Acquisitions	0	478.2
Medical benefits incurred related to
Current year	12,885.1	7,803.2
Prior years	(285.6)	(202.1)
Total	12,599.5	7,601.1
Medical benefits paid related to
Current year	(10,936)	(6,562.2)
Prior years	(1,384.3)	(889.3)
Total	(12,320.3)	(7,451.5)
Ending balance	2,292	2,001
Medicare Health Plans
Reconciliation of the beginning and ending balance of medical benefits payable [Roll Forward]
Beginning balance	823.5	722.5
Acquisitions	0	47.1
Medical benefits incurred related to
Current year	4,732.1	4,051.6
Prior years	(104.9)	(121.8)
Total	4,627.2	3,929.8
Medical benefits paid related to
Current year	(3,858.4)	(3,382.3)
Prior years	(600.7)	(488.3)
Total	(4,459.1)	(3,870.6)
Ending balance	991.6	828.8
Medicare PDPs
Reconciliation of the beginning and ending balance of medical benefits payable [Roll Forward]
Beginning balance	59.1	50.6
Acquisitions	0	0
Medical benefits incurred related to
Current year	700.2	560.4
Prior years	(48.5)	(69.3)
Total	651.7	491.1
Medical benefits paid related to
Current year	(628.4)	(502.9)
Prior years	(3.8)	30
Total	(632.2)	(472.9)
Ending balance	78.6	68.8
Corporate and other
Reconciliation of the beginning and ending balance of medical benefits payable [Roll Forward]
Beginning balance	2	0
Acquisitions	0	2.7
Medical benefits incurred related to
Current year	7.2	1
Prior years	(1.1)	0
Total	6.1	1
Medical benefits paid related to
Current year	(5.5)	(0.8)
Prior years	(0.9)	(0.1)
Total	(6.4)	(0.9)
Ending balance	$ 1.7	$ 2.8

MEDICAL BENEFITS PAYABLE - Narr

MEDICAL BENEFITS PAYABLE - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
MEDICAL BENEFITS PAYABLE [Abstract]
Favorable development of medical benefits payable	$ 440.1	$ 393.2
Favorable development of medical benefits payable excluding the release of the provision for moderately adverse conditions	$ 247	$ 215.2

LEASES (Details)

LEASES (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)
Lessee, Lease, Description [Line Items]
Operating lease expense	$ 19	$ 53.7
Weighted-average remaining lease term	7 years 10 months 24 days	7 years 10 months 24 days
Weighted-average discount rate	5.90%	5.90%
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease terms		14 years

LEASES - Balance Sheet items re

LEASES - Balance Sheet items related to operating leases (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019
Assets:
Right of use assets	$ 247	$ 259.5
Liabilities:
Current	37.3
Noncurrent	231.2
Total liabilities	$ 268.5	$ 277.3

LEASES - Maturity of Operating

LEASES - Maturity of Operating Lease Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019
Leases [Abstract]
2019	$ 13.2
2020	50
2021	49.3
2022	42.5
2023	37.9
2024	35.7
Thereafter	115.2
Total lease payments	343.8
Less: imputed interest	75.3
Present value of lease liabilities	$ 268.5	$ 277.3

LEASES - Supplemental cash flow

LEASES - Supplemental cash flow information related to leases (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Leases [Abstract]
Cash paid for operating leases	$ 36
Leased assets obtained in exchange for new operating lease liabilities	$ 22.9

LEASES - Schedule of non-cancel

LEASES - Schedule of non-cancelable lease payments under ASC Topic 840 (Details) $ in Millions	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 42.4
2020	44.4
2021	45.5
2022	41.9
2023	38.7
2024 and Thereafter	151.4
Total	$ 364.3

INCOME TAXES (Details)

INCOME TAXES (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Effective income tax rate	23.20%	39.30%	22.50%	36.40%

DISCONTINUED OPERATIONS (Detail

DISCONTINUED OPERATIONS (Details) $ in Millions	Aug. 03, 2016subsidiary	Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number Of Subsidiaries Sold | subsidiary	2
Liabilities
Total liabilities		$ 217.3	$ 213.6
Traditional Insurance Business | Discontinued operations, held-for-sale
Assets
Cash and cash equivalents		0.5	0.1
Investments		49.9	42.8
Reinsurance recoverables		166.4	170.2
Other assets		0.5	0.5
Total Assets		217.3	213.6
Liabilities
Reserves and other policy liabilities		164.1	166.9
Other liabilities		53.2	46.7
Total liabilities		$ 217.3	$ 213.6

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) $ in Millions	1 Months Ended					9 Months Ended
	May 31, 2018USD ($)	Jun. 30, 2017USD ($)	Apr. 30, 2017USD ($)	Oct. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Sep. 30, 2019associateformer_officeremployeeLawsuit	Jun. 30, 2013officeremployee	Jan. 31, 2012former_officeremployee	Jan. 31, 2008action
Loss Contingencies [Line Items]
Number of former officers receiving notices of cross appeal | officer							3
Number of former employees found guilty and appealing | employee							4
Number of putative class action lawsuits | Lawsuit						3
Derivative Lawsuits
Loss Contingencies [Line Items]
Number of former officers receiving notices of cross appeal | former_officer						3
Number of former associates being pursued in action filed by entity | associate						2
Number of former employees found guilty and appealing | employee							4
Number of former employees being pursued in action filed by entity						5		5
Number of actions filed in the federal and state courts between October 2007 and January 2008 | action									6
Number of former executives being pursued in action filed by entity | employee								3
Derivative Lawsuits | Mr. Farha Case
Loss Contingencies [Line Items]
Settlement agreement, amount awarded			$ 7.5		$ 7.5
Maximum legal fee obligation					$ 7.5
Derivative Lawsuits | Mr. Farha Case | Securities and Exchange Commission (SEC)
Loss Contingencies [Line Items]
Settlement agreement, amount awarded			12.5
Derivative Lawsuits | Mr. Behrens Case
Loss Contingencies [Line Items]
Settlement agreement, amount awarded			1.5	$ 1.5
Maximum legal fee obligation				$ 1.5
Derivative Lawsuits | Mr. Behrens Case | Securities and Exchange Commission (SEC)
Loss Contingencies [Line Items]
Settlement agreement, amount awarded	$ 4.5		$ 4.5
Derivative Lawsuits | Mr. Bereday Case
Loss Contingencies [Line Items]
Maximum legal fee obligation		$ 2.5