Magellan Health (MGLN) 10-K 28 Feb 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ / shares in Units, $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 21, 2020	Jun. 30, 2019
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	1-6639
Entity Registrant Name	MAGELLAN HEALTH, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	58-1076937
Entity Address, Address Line One	4801 E. Washington Street
Entity Address, City or Town	Phoenix
Entity Address, State or Province	AZ
Entity Address, Postal Zip Code	85034
City Area Code	800
Local Phone Number	642-1716
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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 Listing, Par Value Per Share	$ 0.01
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	MGLN
Security Exchange Name	NASDAQ
Entity Public Float			$ 1.8
Entity Common Stock, Shares Outstanding		24,698,387
Entity Central Index Key	0000019411
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current Assets:
Cash and cash equivalents ($160,967 and $146,455 restricted at December 31, 2018 and December 31, 2019, respectively)	$ 325,249	$ 272,308
Accounts receivable, net	890,065	756,059
Short-term investments ($363,840 and $318,464 restricted at December 31, 2018 and December 31, 2019, respectively)	334,489	382,582
Pharmaceutical inventory	44,962	40,818
Other current assets ($43,401 and $38,602 restricted at December 31, 2018 and December 31, 2019, respectively)	78,278	95,400
Total Current Assets	1,673,043	1,547,167
Property and equipment, net	138,422	150,748
Long-term investments ($2,854 and $10,111 restricted at December 31, 2018 and December 31, 2019, respectively)	10,668	3,161
Deferred income taxes	1,840	3,411
Other long-term assets	82,700	24,530
Goodwill	1,018,156	1,018,156
Other intangible assets, net	167,344	231,883
Total Assets	3,092,173	2,979,056
Current Liabilities:
Accounts payable	88,415	72,077
Accrued liabilities	284,024	231,356
Short-term contingent consideration		8,000
Medical claims payable	409,533	393,547
Other medical liabilities	124,684	169,639
Current debt, finance lease and deferred financing obligations	3,491	24,274
Total Current Liabilities	910,147	898,893
Long-term debt, finance lease and deferred financing obligations	679,125	728,608
Deferred income taxes	17,034	11,167
Tax contingencies	14,841	16,478
Long-term contingent consideration		2,124
Deferred credits and other long-term liabilities	73,243	36,483
Total Liabilities	1,694,390	1,693,753
STOCKHOLDERS' EQUITY
Preferred stock, par value $.01 per share: Authorized - 10,000 shares at December 31, 2018 and December 31, 2019-Issued and outstanding-none
Common stock, par value $.01 per share: Authorized - 100,000 shares at December 31, 2018 and December 31, 2019-Issued and outstanding-53,536 and 23,935 shares at December 31, 2018, respectively, and 54,285 and 24,623 shares at December 31, 2019, respectively	543	535
Other Stockholders' Equity:
Additional paid-in capital	1,386,616	1,326,645
Retained earnings	1,475,207	1,419,449
Accumulated other comprehensive (loss) income	144	(324)
Treasury stock, at cost, 29,601 and 29,662 shares at December 31, 2018 and December 31, 2019, respectively	(1,464,727)	(1,461,002)
Total Stockholders' Equity	1,397,783	1,285,303
Total Liabilities and Stockholders' Equity	$ 3,092,173	$ 2,979,056

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restricted cash and cash equivalents
Restricted cash and cash equivalents	$ 146,455	$ 160,967	$ 229,013
Restricted investments, short-term and long-term
Short-term restricted investments	318,464	363,840
Long term restricted investments	10,111	2,854
Other current restricted assets
Other current restricted assets	$ 38,602	$ 43,401
Preferred stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	10,000	10,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	100,000	100,000
Common stock, issued (in shares)	54,285	53,536
Common stock, outstanding (in shares)	24,623	23,935
Treasury stock
Treasury stock (in shares)	29,662	29,601

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net revenue:
Net revenue	$ 1,802,657	$ 1,828,941	$ 1,788,336	$ 1,739,489	$ 1,844,645	$ 1,853,506	$ 1,810,923	$ 1,805,077	$ 7,159,423	$ 7,314,151	$ 5,838,583
Costs and expenses:
Cost of care	983,678	1,013,006	1,001,886	941,961	959,906	938,031	935,814	928,661	3,940,531	3,762,412	2,413,770
Cost of goods sold	465,614	482,277	461,187	489,793	593,793	571,145	558,419	559,665	1,898,871	2,283,022	2,211,910
Direct service costs and other operating expenses	286,051	266,322	266,434	271,924	277,835	265,471	259,152	269,077	1,090,731	1,071,535	941,883
Depreciation and amortization	33,154	34,157	33,490	30,708	35,358	33,047	33,848	30,407	131,509	132,660	115,706
Interest expense	8,898	9,007	9,141	9,107	9,362	8,990	8,678	8,366	36,153	35,396	25,977
Interest and other income	(4,224)	(4,970)	(5,021)	(4,974)	(4,090)	(4,139)	(3,363)	(2,476)	(19,189)	(14,068)	(5,887)
Total costs and expenses	1,773,171	1,799,799	1,767,117	1,738,519	1,872,164	1,812,545	1,792,548	1,793,700	7,078,606	7,270,957	5,703,359
Income before income taxes	29,486	29,142	21,219	970	(27,519)	40,961	18,375	11,377	80,817	43,194	135,224
Provision for income taxes	8,902	7,868	7,606	539	448	13,816	4,824	(75)	24,915	19,013	25,083
Net income					$ (27,967)	$ 27,145	$ 13,551	$ 11,452	55,902	24,181	110,141
Less: net income (loss) attributable to non-controlling interest											(66)
Net income attributable to Magellan	$ 20,584	$ 21,274	$ 13,613	$ 431					$ 55,902	$ 24,181	$ 110,207
Net income per common share:
Basic (in dollars per share)	$ 0.84	$ 0.87	$ 0.56	$ 0.02	$ (1.16)	$ 1.11	$ 0.55	$ 0.47	$ 2.31	$ 0.99	$ 4.72
Diluted (in dollars per share)	$ 0.83	$ 0.86	$ 0.56	$ 0.02	$ (1.16)	$ 1.09	$ 0.53	$ 0.45	$ 2.28	$ 0.97	$ 4.51
Managed care and other
Net revenue:
Net revenue	$ 1,292,335	$ 1,303,936	$ 1,283,143	$ 1,223,979	$ 1,207,552	$ 1,235,787	$ 1,215,340	$ 1,219,763	$ 5,103,393	$ 4,878,442	$ 3,479,182
PBM
Net revenue:
Net revenue	$ 510,322	$ 525,005	$ 505,193	$ 515,510	$ 637,093	$ 617,719	$ 595,583	$ 585,314	$ 2,056,030	$ 2,435,709	$ 2,359,401

CONSOLIDATED STATEMENTS OF IN_2

CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED STATEMENTS OF INCOME
Stock compensation expense	$ 25.5	$ 29.5	$ 39.1
Changes in fair value of contingent consideration	$ (2.1)	$ 1.3	$ 0.7

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 55,902	$ 24,181	$ 110,141
Other comprehensive income:
Unrealized (loss) gain on available-for-sale securities	468	56	(205)
Comprehensive income	56,370	24,237	109,936
Less: comprehensive loss attributable to non-controlling interest			(66)
Comprehensive income attributable to Magellan	$ 56,370	$ 24,237	$ 110,002

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net of income tax provision	$ 150	$ 18	$ (8)

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Common Stock In Treasury	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss) Income	Total
Balance at Dec. 31, 2016	$ 520	$ (1,376,197)	$ 1,186,283	$ 1,289,288	$ (175)	$ 1,099,719
Balance (in shares) at Dec. 31, 2016	51,993,000	(28,476,000)
Increase (Decrease) in Stockholders' Equity
Stock compensation expense			39,116			39,116
Exercise of stock options	$ 8		44,347			$ 44,355
Exercise of stock options (in shares)	831,000					831,186
Issuance of equity	$ 2		361			$ 363
Issuance of equity (in shares)	149,000
Repurchase of stock		$ (21,765)				(21,765)
Repurchase of stock (in shares)		(295,000)
Adjustment to non-controlling interest			4,704			4,704
Net income				110,207		110,207
Other comprehensive income (loss)-other					(205)	(205)
Balance at Dec. 31, 2017	$ 530	$ (1,397,962)	1,274,811	1,399,495	(380)	1,276,494
Balance (in shares) at Dec. 31, 2017	52,973,000	(28,771,000)
Increase (Decrease) in Stockholders' Equity
Stock compensation expense			29,472			29,472
Exercise of stock options	$ 4		23,060			$ 23,064
Exercise of stock options (in shares)	409,000					409,208
Issuance of equity	$ 1		(698)			$ (697)
Issuance of equity (in shares)	154,000
Repurchase of stock		$ (63,040)				(63,040)
Repurchase of stock (in shares)		(830,000)
Net income				24,181		24,181
Other comprehensive income (loss)-other					56	56
Adoption of ASC				(4,227)		(4,227)
Balance at Dec. 31, 2018	$ 535	$ (1,461,002)	1,326,645	1,419,449	(324)	$ 1,285,303
Balance (in shares) at Dec. 31, 2018	53,536,000	(29,601,000)				23,935,000
Increase (Decrease) in Stockholders' Equity
Stock compensation expense			25,501			$ 25,501
Exercise of stock options	$ 7		32,708			$ 32,715
Exercise of stock options (in shares)	543,000					543,752
Issuance of equity	$ 1		1,762			$ 1,763
Issuance of equity (in shares)	206,000
Repurchase of stock		$ (3,725)				(3,725)
Repurchase of stock (in shares)		(61,000)
Net income				55,902		55,902
Other comprehensive income (loss)-other					468	468
Adoption of ASC				(144)		(144)
Balance at Dec. 31, 2019	$ 543	$ (1,464,727)	$ 1,386,616	$ 1,475,207	$ 144	$ 1,397,783
Balance (in shares) at Dec. 31, 2019	54,285,000	(29,662,000)				24,623,000

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 55,902	$ 24,181	$ 110,141
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	131,509	132,660	115,706
Non-cash interest expense	1,537	1,221	4,757
Non-cash stock compensation expense	25,501	29,472	39,116
Non-cash income tax provision	7,052	(1,725)	(30,981)
Non-cash amortization on investments	(433)	1,344	3,924
Changes in assets and liabilities, net of effects from acquisitions of businesses:
Accounts receivable, net	(133,999)	(99,295)	(40,910)
Pharmaceutical inventory	(4,144)	127	17,605
Other assets	19,492	(25,774)	(4,565)
Accounts payable and accrued liabilities	56,843	9,139	(84,445)
Medical claims payable and other medical liabilities	(28,969)	72,347	26,235
Contingent consideration	(3,877)	1,307	696
Tax contingencies	(1,352)	1,803	1,681
Deferred credits and other long-term liabilities	(10,668)	18,020	3,218
Other	1,452	17	95
Net cash provided by operating activities	115,846	164,844	162,273
Cash flows from investing activities:
Capital expenditures	(60,402)	(68,275)	(57,232)
Acquisitions and investments in businesses, net of cash acquired	(727)	(958)	(232,403)
Purchases of investments	(514,324)	(557,232)	(449,873)
Proceeds from maturities and sales of investments	555,960	498,032	423,118
Net cash used in investing activities	(19,493)	(128,433)	(316,390)
Cash flows from financing activities:
Proceeds from issuance of debt			1,041,736
Payments to acquire treasury stock	(4,125)	(62,640)	(21,765)
Proceeds from exercise of stock options	32,708	23,064	44,355
Payments on debt, finance lease and deferred financing obligations	(67,511)	(122,239)	(803,393)
Payments on contingent consideration	(6,247)		(3,032)
Other	1,763	(1,020)	(9,560)
Net cash used in financing activities	(43,412)	(162,835)	248,341
Net (decrease) increase in cash and cash equivalents	52,941	(126,424)	94,224
Cash and cash equivalents at beginning of period	272,308	398,732	304,508
Cash and cash equivalents at end of period	325,249	272,308	398,732
Non-cash investing activities:
Assets acquired under finance leases and deferred financing	$ 3,302	$ 20,576	$ 2,418

General

General	12 Months Ended
	Dec. 31, 2019
General
General	1. General Basis of Presentation The consolidated financial statements of Magellan Health, Inc., a Delaware corporation (“Magellan”), include Magellan and its subsidiaries (together with Magellan, the “Company”). All significant intercompany accounts and transactions have been eliminated in consolidation. Business Overview The Company provides managed care services for some of the most complex areas of healthcare. The Company offers innovative solutions that combine analytics, technology and clinical rigor to drive better decision making, positively impact members’ health outcomes and optimize the cost of care for the customers Magellan serves. The Company provides services to health plans and other managed care organizations (“MCOs”), employers, labor unions, various military and governmental agencies and third-party administrators (“TPAs”). Magellan operates three segments: Healthcare, Pharmacy Management and Corporate. Healthcare The Healthcare segment “Healthcare” consists of two reporting units – Behavioral & Specialty Health and Magellan Complete Care (“MCC”). The Behavioral & Specialty Health reporting unit’s customers include health plans, accountable care organizations (“ACOs”), employers, the United States military and various federal government agencies for whom Magellan provides carve-out management services for (i) behavioral health, (ii) employee assistance plans (“EAP”) and (iii) other areas of specialty healthcare including diagnostic imaging, musculoskeletal management, cardiac and physical medicine. These management services can be applied broadly across commercial, Medicaid and Medicare populations, or on a more targeted basis for our health plans and ACO customers. The Behavioral & Specialty Health unit also includes Magellan’s carve-out behavioral health contracts with various state Medicaid agencies. The MCC reporting unit contracts with state Medicaid agencies and the Centers for Medicare and Medicaid Services (“CMS”) to manage care for beneficiaries under various Medicaid and Medicare programs. MCC manages a wide range of services from total medical cost to carve out long-term support services. MCC largely focuses on managing care for more acute special populations including individuals with serious mental illness (“SMI”), dual eligibles, aged, blind and disabled (“ABD”) and other populations with unique and often complex healthcare needs. Magellan’s coordination and management of these healthcare and long-term support services are provided through its comprehensive network of medical and behavioral health professionals, clinics, hospitals, skilled nursing facilities, home care agencies and ancillary service providers. This network of credentialed providers is integrated with clinical and quality improvement programs to improve access to care and enhance the healthcare experience for individuals in need of care, while at the same time making the cost of these services more affordable for our customers. The Company generally does not directly provide or own any provider of treatment services, although it does employ licensed behavioral health counselors to deliver non-medical counseling under certain government contracts. The Company provides its Healthcare management services primarily through: (i) risk- based contractual arrangements, where the Company assumes all or a substantial portion of the responsibility for the cost of providing treatment services in exchange for a fixed PMPM fee, or (ii) administrative services only (“ASO”) contractual arrangements, where the Company provides services such as utilization review, claims administration and/or provider network management, but does not assume full responsibility for the cost of the treatment services, in exchange for an administrative fee and, in some instances, a gain share. Pharmacy Management The Pharmacy Management segment (“Pharmacy Management”) is comprised of services that provide clinical and financial management of pharmaceuticals paid under both the medical and the pharmacy benefit. Pharmacy Management’s customer solutions include: (i) pharmacy benefit management (“PBM”) services, including pharmaceutical dispensing operations; (ii) pharmacy benefit administration (“PBA”) for state Medicaid and other government sponsored programs; (iii) clinical and formulary management programs; (iv) medical pharmacy management programs; and (v) programs for the integrated management of specialty drugs across both the medical and pharmacy benefit that treat complex conditions, regardless of site of service, method of delivery, or benefit reimbursement. These services are available individually, in combination, or in a fully integrated manner. The Company markets its pharmacy management services to managed care organizations, employers, third party administrators, state governments, Medicare Part D, and other government agencies, exchanges, brokers and consultants. In addition, the Company will continue to upsell its pharmacy services to its existing customers and market its pharmacy solutions to the Healthcare customer base. Pharmacy Management contracts with its customers for services using risk-based, gain share or ASO arrangements. In addition, Pharmacy Management provides services to the Healthcare segment for most of the MCC business. Corporate This segment of the Company is comprised primarily of amounts not allocated to the Healthcare and Pharmacy Management segments that are largely associated with costs related to being a publicly traded company.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, “Leases” (“ASU 2016-02”). This ASU amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets. The FASB also issued various ASUs which subsequently amended ASU 2016-02. These amendments and ASU 2016-02, collectively known as Accounting Standard Codification 842 (“ASC 842”), are effective for annual and interim reporting periods of public entities beginning after December 15, 2018. The Company adopted ASC 842 on a modified retrospective ​ ​ The cumulative effect of the change to our consolidated January 1, 2019 balance sheet for the adoption of ASC 842 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at December 31, 2018 Adjustments Due to ASC 842 Balance at January 1, 2019 Assets ​ ​ ​ ​ ​ ​ ​ ​ Deferred income taxes $ 3,411 ​ $ 51 ​ $ 3,462 Other long-term assets ​ 24,530 ​ ​ 59,820 ​ ​ 84,350 Total Assets ​ 2,979,056 ​ ​ 59,871 ​ ​ 3,038,927 ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities and Stockholders' Equity ​ ​ ​ ​ ​ ​ ​ ​ Accrued liabilities ​ 231,356 ​ ​ 13,018 ​ ​ 244,374 Total Current Liabilities ​ 898,893 ​ ​ 13,018 ​ ​ 911,911 Deferred credits and other long-term liabilities ​ 36,483 ​ ​ 46,999 ​ ​ 83,482 Total Liabilities ​ 1,693,753 ​ ​ 60,017 ​ ​ 1,753,770 Retained earnings ​ 1,419,449 ​ ​ (144) ​ ​ 1,419,305 Total Stockholders' Equity ​ 1,285,303 ​ ​ (144) ​ ​ 1,285,159 Total Liabilities and Stockholders' Equity ​ 2,979,056 ​ ​ 59,871 ​ ​ 3,038,927 ​ In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (“ASU 2016-13”). This ASU amends the accounting on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities. This guidance is effective for annual and interim periods of public entities beginning after December 15, 2019, with early adoption permitted for fiscal years beginning after December 31, 2018. The Company does not anticipate the adoption of this ASU will have a material impact on the Company’s consolidated results of operation, financial position and cash flows. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment” (“ASU 2017-04”). The amendments in this ASU eliminate the requirement to calculate the implied fair value of goodwill to measure a goodwill impairment charge. This guidance is effective for annual and interim periods of public entities beginning after December 15, 2019, with early adoption permitted. The Company does not anticipate the adoption of this ASU will have a material impact on the Company’s consolidated results of operation, financial position and cash flows. In August 2018, the FASB issued ASU No. 2018-15, “Intangibles-Goodwill and Other–Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract” (“ASU 2018-15”). This ASU aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This guidance is effective for annual and interim periods of public entities beginning after December 15, 2019, with early adoption permitted. The Company does not anticipate the adoption of this ASU will have a material impact on the Company’s consolidated results of operation, financial position and cash flows. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant estimates of the Company can include, among other things, valuation of goodwill and intangible assets, medical claims payable, other medical liabilities, stock compensation assumptions, tax contingencies and legal liabilities. In addition, the Company also makes estimates in relation to revenue recognition under Accounting Standard Codification 606 (“ASC 606”) which are explained in more detail in “ Revenue Recognition ​ ​ Revenue Recognition ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2018 ​ Healthcare Pharmacy Management Elimination Total Major Service Lines ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Behavioral & Specialty Health ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP $ 1,511,532 ​ $ — ​ $ (263) ​ $ 1,511,269 EAP risk-based ​ 349,751 ​ ​ — ​ ​ — ​ ​ 349,751 ASO ​ 247,953 ​ ​ 34,130 ​ ​ (344) ​ ​ 281,739 Magellan Complete Care ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP ​ 2,473,570 ​ ​ — ​ ​ — ​ ​ 2,473,570 ASO ​ 55,816 ​ ​ — ​ ​ — ​ ​ 55,816 PBM, including dispensing ​ — ​ ​ 2,183,151 ​ ​ (189,708) ​ ​ 1,993,443 Medicare Part D ​ — ​ ​ 442,266 ​ ​ — ​ ​ 442,266 PBA ​ — ​ ​ 132,112 ​ ​ — ​ ​ 132,112 Formulary management ​ — ​ ​ 70,900 ​ ​ — ​ ​ 70,900 Other ​ — ​ ​ 3,285 ​ ​ — ​ ​ 3,285 Total net revenue $ 4,638,622 ​ $ 2,865,844 ​ $ (190,315) ​ $ 7,314,151 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Type of Customer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Government $ 3,432,901 ​ $ 946,606 ​ $ — ​ $ 4,379,507 Non-government ​ 1,205,721 ​ ​ 1,919,238 ​ ​ (190,315) ​ ​ 2,934,644 Total net revenue $ 4,638,622 ​ $ 2,865,844 ​ $ (190,315) ​ $ 7,314,151 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Timing of Revenue Recognition ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Transferred at a point in time $ — ​ $ 2,625,417 ​ $ (189,708) ​ $ 2,435,709 Transferred over time ​ 4,638,622 ​ ​ 240,427 ​ ​ (607) ​ ​ 4,878,442 Total net revenue $ 4,638,622 ​ $ 2,865,844 ​ $ (190,315) ​ $ 7,314,151 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2019 ​ Healthcare Pharmacy Management Elimination Total Major Service Lines ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Behavioral & Specialty Health ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP $ 1,504,472 ​ $ — ​ $ (290) ​ $ 1,504,182 EAP risk-based ​ 339,377 ​ ​ — ​ ​ — ​ ​ 339,377 ASO ​ 237,186 ​ ​ 40,348 ​ ​ (302) ​ ​ 277,232 Magellan Complete Care ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP ​ 2,695,132 ​ ​ — ​ ​ — ​ ​ 2,695,132 ASO ​ 62,379 ​ ​ — ​ ​ — ​ ​ 62,379 PBM, including dispensing ​ — ​ ​ 1,949,225 ​ ​ (180,799) ​ ​ 1,768,426 Medicare Part D ​ — ​ ​ 287,604 ​ ​ — ​ ​ 287,604 PBA ​ — ​ ​ 137,885 ​ ​ — ​ ​ 137,885 Formulary management ​ — ​ ​ 84,567 ​ ​ — ​ ​ 84,567 Other ​ — ​ ​ 2,639 ​ ​ — ​ ​ 2,639 Total net revenue $ 4,838,546 ​ $ 2,502,268 ​ $ (181,391) ​ $ 7,159,423 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Type of Customer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Government $ 3,674,152 ​ $ 831,673 ​ $ — ​ $ 4,505,825 Non-government ​ 1,164,394 ​ ​ 1,670,595 ​ ​ (181,391) ​ ​ 2,653,598 Total net revenue $ 4,838,546 ​ $ 2,502,268 ​ $ (181,391) ​ $ 7,159,423 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Timing of Revenue Recognition ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Transferred at a point in time $ — ​ $ 2,236,829 ​ $ (180,799) ​ $ 2,056,030 Transferred over time ​ 4,838,546 ​ ​ 265,439 ​ ​ (592) ​ ​ 5,103,393 Total net revenue $ 4,838,546 ​ $ 2,502,268 ​ $ (181,391) ​ $ 7,159,423 ​ Per Member Per Month (“PMPM”) Revenue. Under certain government contracts, our risk scores are compared with the overall average risk scores for the relevant state and market pool. Generally, if our risk score is below the average risk score we are required to make a risk adjustment payment into the risk pool, and if our risk score is above the average risk score we will receive a risk adjustment payment from the risk pool. Risk adjustments can have a positive or negative retroactive impact to rates. ​ Pharmacy Benefit Management Revenue. The Company’s customers for PBM business, including pharmaceutical dispensing operations, are generally comprised of MCOs, employer groups and health plans. PBM relationships generally have an expected term of one year or longer. A master services arrangement (“MSA”) is executed by the Company and the customer, which outlines the terms and conditions of the PBM services to be provided. When a member in the customer’s organization submits a prescription, a claim is created which is presented for approval. The acceptance of each individual claim creates enforceable rights and obligations for each party and represents a separate contract. For each individual claim, the performance obligations are limited to the processing and adjudication of the claim, or dispensing of the products purchased. Generally, the transaction price for PBM services is explicitly listed in each contract and does not represent variable consideration. The Company recognizes PBM revenue, which consists of a negotiated prescription price (ingredient cost plus dispensing fee), co-payments and any associated administrative fees, when claims are adjudicated or the drugs are shipped. The Company recognizes PBM revenue on a gross basis (i.e. including drug costs and co-payments) as it is acting as the principal in the arrangement, controls the underlying service, and is contractually obligated to its clients and network pharmacies, which is a primary indicator of gross reporting. In addition, the Company is solely responsible for the claims adjudication process, negotiating the prescription price for the pharmacy, collecting payments from the client for drugs dispensed by the pharmacy, and managing the total prescription drug relationship with the client’s members. If the Company enters into a contract where it is only an administrator, and does not assume any of the risks previously noted, revenue will be recognized on a net basis. For dispensing, at the time of shipment, the earnings process is complete; the obligation of the Company’s customer to pay for the specialty pharmaceutical drugs is fixed, and, due to the nature of the product, the member may neither return the specialty pharmaceutical drugs nor receive a refund. Medicare Part D. st Pharmacy Benefit Administration Revenue. Formulary Management Revenue. The Company administers formulary management programs for certain clients through which the Company coordinates the achievement, calculation and collection of rebates and administrative fees from pharmaceutical manufacturers on behalf of clients. Formulary management contracts generally have a term of one year or longer. All formulary management contracts have a single performance obligation that constitutes a series for the provision of rebate services for a drug, with utilization measured and settled on a quarterly basis, for the duration of the arrangement. The Company retains its administrative fee and/or a percentage of rebates that is included in its contract with the client from collecting the rebate from the manufacturer. While the administrative fee and/or the percentage of rebates retained is fixed, there is an unknown quantity of pharmaceutical purchases (utilization) during each quarter; therefore the transaction price itself is variable. The Company uses the expected value methodology to estimate the total rebates earned each quarter based on estimated volumes of pharmaceutical purchases by the Company’s clients during the quarter, as well as historical and/or anticipated retained rebate percentages. The Company does not record as rebate revenue any rebates that are passed through to its clients. ​ In relation to the Company’s PBM business, the Company administers rebate programs through which it receives rebates from pharmaceutical manufacturers that are shared with its customers. The Company recognizes rebates when the Company is entitled to them and when the amounts of the rebates are determinable. The amount recorded for rebates earned by the Company from the pharmaceutical manufacturers is recorded as a reduction of cost of goods sold. Government EAP Risk-Based Revenue. The Company has certain contracts with federal customers for the provision of various managed care services, which are classified as EAP risk-based business. These contracts are generally multi-year arrangements. The Company’s federal contracts are reimbursed on either a fixed fee basis or a cost reimbursement basis. The performance obligation on a fixed fee contract is to stand ready to provide the staffing required for the contracted period. For fixed fee contracts, the Company believes the invoiced amount corresponds directly with the value to the customer of the Company’s performance completed to date; therefore, the Company is utilizing the “right to invoice” practical expedient, with revenue recognition in the amount for which the Company has the right to invoice. The performance obligation on a cost reimbursement contract is to stand ready to provide the activity or services purchased by the customer, such as the operation of a counseling services group or call center. The performance obligation represents a series for the duration of the arrangement. The reimbursement rate is fixed per the contract; however, the level of activity (e.g., number of hours, number of counselors or number of units) is variable. A majority of the Company’s cost reimbursement transaction price relates specifically to its efforts to transfer the service for a distinct increment of the series (e.g. day or month) and is recognized as revenue when the portion of the series for which it relates has been provided (i.e. as the Company provides hours, counselors or units of service). In accordance with ASC 606-10-50-13, the Company is required to include disclosure on its remaining performance obligations as of the end of the current reporting period. Due to the nature of the contracts in the Company’s PBM and Part D business, these reporting requirements are not applicable. The majority of the Company’s remaining contracts meet certain exemptions as defined in ASC 606-10-50-14 through 606-10-50-14A, including (i) performance obligation is part of a contract that has an original expected duration of one year or less; (ii) the right to invoice practical expedient; and (iii) variable consideration related to unsatisfied performance obligations that is allocated entirely to a wholly unsatisfied promise to transfer a distinct service that forms part of a single performance obligation, and the terms of that variable consideration relate specifically to our efforts to transfer the distinct service, or to a specific outcome from transferring the distinct service. For the Company’s contracts that pertain to these exemptions: (i) the remaining performance obligations primarily relate to the provision of managed healthcare services to the customers’ membership; (ii) the estimated remaining duration of these performance obligations ranges from the remainder of the current calendar year to three years; and (iii) variable consideration for these contracts primarily includes net per member per month fees associated with unspecified membership that fluctuates throughout the contract. Accounts Receivable, Contract Assets and Contract Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ ​ 2018 ​ 2019 ​ $ Change ​ % Change ​ Accounts receivable $ 786,395 ​ $ 915,656 ​ $ 129,261 ​ ​ 16.4% ​ Contract assets ​ 4,647 ​ ​ 2,231 ​ ​ (2,416) ​ ​ (52.0%) ​ Contract liabilities - current ​ 16,853 ​ ​ 6,728 ​ ​ (10,125) ​ ​ (60.1%) ​ Contract liabilities - long-term ​ 13,441 ​ ​ 11,099 ​ ​ (2,342) ​ ​ (17.4%) ​ ​ 2020 2021 2022 2023 Significant Customers Customers exceeding ten percent of the consolidated Company’s net revenues The Company has contracts with the Commonwealth of Virginia (the “Virginia Contracts”). The Company began providing Medicaid managed long-term services and supports to enrollees in the Commonwealth Coordinated Care Plus (“CCC Plus”) program on August 1, 2017. The CCC Plus contract expires annually on December 31, and automatically renews annually on January 1 for a period of five The Company had a contract with the State of New York (the “New York Contract”) to provide integrated managed care services to Medicaid and Medicare enrollees in the State of New York. The Company’s New York Contract terminated on December 31, 2016; however, the Company, along with other participating managed care plans in the state, continues to provide services while a new contract is being finalized. The Company began recognizing revenue in relation to the New York Contract on January 1, 2014 as a result of the acquisition of AlphaCare Holdings, Inc. The Company’s revenues under the New York Contracts increased starting on November 1, 2017 as a result of the acquisition of SWH Holdings, Inc. The New York Contracts generated net revenues of $265.2 million, $691.6 million and $836.4 million for the years ended December 31, 2017, 2018 and 2019, respectively. The Company has contracts with the Commonwealth of Massachusetts and CMS (the “Massachusetts Contracts”) to provide integrated managed care services to Medicaid and Medicare enrollees in the Commonwealth of Massachusetts. Medicaid services are provided under a Senior Care Options contract (“SCO Contract”) which began on January 1, 2016 and extends through December 31, 2021, with the potential for up to five additional one year extensions. The Commonwealth of Massachusetts may terminate the contract with cause without prior notice and upon 180 days ’ notice without cause. Medicare services are provided under a one-year contract with CMS. The CMS contract currently extends through December 31, 2019. The Company began recognizing revenue in relation to the Massachusetts Contracts on November 1, 2017 as a result of the acquisition of SWH Holdings, Inc. The Massachusetts Contracts generated net revenues of $109.1 million, $682.1 million and $718.9 million for the years ended December 31, 2017, 2018 and 2019, respectively. ​ Customers exceeding ten percent of segment net revenues In addition to the Massachusetts Contracts, New York Contract and Virginia Contracts previously discussed, the following customers generated in excess of ten percent of net revenues for the respective segment for the respective segment for the years ended December 31, 2017, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Term Date 2017 2018 2019 Healthcare ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Customer A ​ December 31, 2023 ​ $ 605,917 ​ $ 618,227 ​ $ 211,106 * ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pharmacy Management ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Customer B ​ March 31, 2021 ​ ​ 346,405 ​ ​ 344,479 ​ ​ 335,682 ​ * Revenue amount did not exceed 10 percent of net revenues for the respective segment for the year presented. Amount is shown for comparative purposes only. Concentration of Business The Company also has a significant concentration of business with various counties in the State of Pennsylvania (the “Pennsylvania Counties”) which are part of the Pennsylvania Medicaid program, with members under its contract with CMS and with various agencies and departments of the United States federal government. Net revenues from the Pennsylvania Counties in the aggregate totaled $490.0 million, $544.6 million and $537.8 million for the years ended December 31, 2017, 2018 and 2019, respectively. Net revenues from members in relation to its contract with CMS in aggregate totaled $511.0 million, $442.3 million and $287.6 million for the years ended December 31, 2017, 2018 and 2019, respectively. Net revenues from contracts with various agencies and departments of the United States federal government in aggregate totaled $341.5 million, $308.7 million, and $299.2 million for the years ended December 31, 2017, 2018 and 2019, respectively. The Company’s contracts with customers typically have stated terms of one one Income Taxes The Company files a consolidated federal income tax return with its eighty-percent or more controlled subsidiaries. The Company previously filed separate consolidated federal income tax returns for AlphaCare of New York, Inc. (“AlphaCare”) and its parent, AlphaCare Holdings, Inc. (“AlphaCare Holdings”). During 2017, AlphaCare and AlphaCare Holdings became members of the Magellan federal consolidated group. The Company and its subsidiaries also file income tax returns in various state and local jurisdictions. The Company estimates income taxes for each of the jurisdictions in which it operates. This process involves determining both permanent and temporary differences resulting from differing treatment for tax and book purposes. Deferred tax assets and/or liabilities are determined by multiplying the temporary differences between the financial reporting and tax reporting bases for assets and liabilities by the enacted tax rates expected to be in effect when such differences are recovered or settled. The Company then assesses the likelihood that the deferred tax assets will be recovered from the reversal of temporary differences, the implementation of feasible and prudent tax planning strategies, and future taxable income. To the extent the Company cannot conclude that recovery is more likely than not, it establishes a valuation allowance. The effect of a change in tax rates on deferred taxes is recognized in income in the period that includes the enactment date. Reversals of both valuation allowances and unrecognized tax benefits are recorded in the period they occur, typically as reductions to income tax expense. The Company recognizes interim period income taxes by estimating an annual effective tax rate and applying it to year-to-date results. The estimated annual effective tax rate is periodically updated throughout the year based on actual results to date and an updated projection of full year income. Although the effective tax rate approach is generally used for interim periods, taxes on significant, unusual and infrequent items are recognized at the statutory tax rate entirely in the period the amounts are realized. Health Care Reform The Patient Protection and the Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010 (collectively, the “Health Reform Law”), imposes a mandatory annual fee on health insurers for each calendar year beginning on or after January 1, 2014. The Company has obtained rate adjustments from customers which the Company expects will cover the direct costs of these fees and the impact from non-deductibility of such fees for federal and state income tax purposes. To the extent the Company has such a customer that does not renew, there may be some impact due to taxes paid where the timing and amount of recoupment of these additional costs is uncertain. In the event the Company is unable to obtain rate adjustments to cover the financial impact of the annual fee, the fee may have a material impact on the Company. The Consolidated Appropriations Act of 2016 imposed a one-year moratorium on the Patient Protection and Affordable Care Act health insurer fee (“HIF”) fee, suspending its application for 2017. The HIF fee went back into effect for 2018, however, on January 23, 2018 the United States Congress passed the Continuing Resolution which imposed another one-year moratorium on the HIF fee, suspending its application for 2019. For 2018, the HIF fees were $29.9 million, which have been paid and are included in direct service costs and other operating expenses in the consolidated statements of income. Cash and Cash Equivalents Cash equivalents are short-term, highly liquid interest-bearing investments with maturity dates of three months or less when purchased, consisting primarily of money market instruments. Book overdrafts are reflected within accounts payable on the balance sheets. There were no book overdrafts at December 31, 2018. At December 31, 2019, the Company had $0.5 million in book overdrafts. At December 31, 2019, the Company’s excess capital and undistributed earnings for the Company’s regulated subsidiaries of $134.8 million are included in cash and cash equivalents. Restricted Assets The Company has certain assets which are considered restricted for: (i) the payment of claims under the terms of certain managed care contracts; (ii) regulatory purposes related to the payment of claims in certain jurisdictions; and (iii) the maintenance of minimum required tangible net equity levels for certain of the Company’s subsidiaries. Significant restricted assets of the Company as of December 31, 2018 and 2019 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 2019 Restricted cash and cash equivalents ​ $ 160,967 ​ $ 146,455 ​ Restricted short-term investments ​ 363,840 ​ 318,464 ​ Restricted deposits (included in other current assets) ​ 43,401 ​ 38,602 ​ Restricted long-term investments ​ 2,854 ​ 10,111 ​ Total ​ $ 571,062 ​ $ 513,632 ​ The Company’s equity in restricted net assets of consolidated subsidiaries represented approximately 28.1% of the Company’s consolidated stockholders’ equity as of December 31, 2019 and consisted of net assets of the Company which were restricted as to transfer to Magellan in the form of cash dividends, loans or advances under regulatory restrictions. Fair Value Measurements The Company has certain assets and liabilities that are required to be measured at fair value on a recurring basis. These assets and liabilities are to be measured using inputs from the three levels of the fair value hierarchy, which are as follows: Level 1—Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). Level 3—Unobservable inputs that reflect the Company’s assumptions about the assumptions that market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available, including the Company’s data. In accordance with the fair value hierarchy described above, the following table shows the fair value of the Company’s financial assets and liabilities that are required to be measured at fair value as of December 31, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 ​ ​ Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents (1) $ — $ 263,462 $ — $ 263,462 ​ Investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Government and agency securities ​ 67,815 ​ — ​ — ​ 67,815 ​ Obligations of government-sponsored enterprises (2) ​ — ​ 5,229 ​ — ​ 5,229 ​ Corporate debt securities ​ — ​ 292,049 ​ — ​ 292,049 ​ Certificates of deposit ​ — ​ 20,650 ​ — ​ 20,650 ​ Total assets held at fair value ​ $ 67,815 ​ $ 581,390 ​ $ — ​ $ 649,205 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ $ — ​ $ — ​ $ 10,124 ​ $ 10,124 ​ Total liabilities held at fair value ​ $ — ​ $ — ​ $ 10,124 ​ $ 10,124 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents (3) $ — $ 313,509 $ — $ 313,509 ​ Investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Government and agency securities ​ 104,159 ​ — ​ — ​ 104,159 ​ Corporate debt securities ​ — ​ 239,693 ​ — ​ 239,693 ​ Certificates of deposit ​ — ​ 1,305 ​ — ​ 1,305 ​ Total assets held at fair value ​ $ 104,159 ​ $ 554,507 ​ $ — ​ $ 658,666 ​ (1) Excludes $8.8 million of cash held in bank accounts by the Company. (2) Includes investments in notes issued by the Federal Home Loan Bank, Federal Farm Credit Banks and Federal National Mortgage Association. (3) Excludes $11.7 million of cash held in bank accounts by the Company. For the years ended December 31, 2018 2019 Company not The carrying values of financial instruments, including accounts receivable and accounts payable, approximate their fair values due to their short-term maturities. The fair value of the Notes (as defined below) of $403.4 million as of December 31, 2019 was determined based on quoted market prices and would be classified within Level 1 of the fair value hierarchy. The estimated fair value of the Company’s term loan of $280.6 million as of December 31, 2019 was based on current interest rates for similar types of borrowings and is in Level 2 of the fair value hierarchy. The estimated fair values may not represent actual values of the financial instruments that could be realized as of the balance sheet date or that will be realized in the future. All of the Company’s investments are classified as “available-for-sale” and are carried at fair value. As of the balance sheet date, the fair value of contingent consideration is determined based on probabilities of payment, projected payment dates, discount rates, projected operating income, member engagement and new contract execution. The Company used a probability weighted discounted cash flow method to arrive at the fair value of the contingent consideration. As the fair value measurement for the contingent consideration is based on inputs not observed in the market, these measurements are classified as Level 3 measurements as defined by fair value measurement guidance. The unobservable inputs used in the fair value measurement include the discount rate, probabilities of payment and projected payment dates. As of December 31, 2018, the Company estimated undiscounted future contingent payments of $10.6 million. As of December 31, 2018, the fair value of the short-term and long-term contingent consideration was $8.0 million and $2.1 million, respectively, and is included in short-term contingent consideration and long-term contingent consideration, respectively, in the consolidated balance sheets. As of December 31, 2019, the Company had no estimated future contingent payments. The change in the fair value of the contingent consideration was $0.7 million, $1.3 million and $(2.1) million for the years ended December 31, 2017, 2018 and 2019, respectively, which were recorded as direct service costs and other operating expenses in the consolidated statements of income. The decreases during 2019 were mainly a result of changes in the estimated undiscounted liability. The following table summarizes the Company’s liability for contingent consideration (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ 2018 2019 Balance as of beginning of period ​ $ 8,817 ​ $ 10,124 ​ Changes in fair value ​ 1,307 ​ (2,124) ​ Payments ​ ​ — ​ ​ (8,000) ​ Balance as of end of period ​ $ 10,124 ​ $ — ​ ​ Investments All of the Company’s investments are classified as “available-for-sale” and are carried at fair value. Securities which have been classified as Level 1 are measured using quoted market prices in active markets for identical assets or liabilities while those which have been classified as Level 2 are measured using quoted prices for identical assets and liabilities in markets that are not active. The Company’s policy is to classify all investments with contractual maturities within one year as current. Investment income is recognized when earned and reported net of investment expenses. Net unrealized holding gains or losses are excluded from earnings and are reported, net of tax, as “accumulated other comprehensive income (loss)” in the accompanying consolidated balance sheets and consolidated statements of comprehensive income until realized, unless the losses are deemed to be other-than-temporary. Realized gains or losses, including any provision for other-than-temporary declines in value, are included in the consolidated statements of income. If a debt security is in an unrealized loss position and the Company has the intent to sell the debt security, or it is more likely than not that the Company will have to sell the debt security before recovery of its amortized cost basis, the decline in value is deemed to be other-than-temporary and is recorded to other-than-temporary impairment losses recognized in income in the consolidated statements of income. For impaired debt securities that the Company does not intend to sell or it is more likely than not that the Company will not have to sell such securities, but the Company expects that it will not fully recover the amortized cost basis, the credit component of the other-than-temporary impairment is recognized in other-than-t

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2019
Acquisitions
Acquisitions	3. Acquisitions Acquisition of SWH Holdings, Inc. Pursuant to the July 13, 2017 Agreement and Plan of Merger (“the SWH Agreement”), on October 31, 2017 the Company acquired (the “SWH Acquisition”) all of the outstanding equity interests of SWH Holdings, Inc. (“SWH”). SWH is a healthcare company focused on serving complex, high-risk populations, providing Medicare and Medicaid dual-eligible benefits to members in Massachusetts and New York. ​

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2019
Benefit Plans
Benefit Plans	4. Benefit Plans The Company has a defined contribution retirement plan (the “401(k) Plan”). Employee participants can elect to contribute up to 75 percent of their compensation, subject to Internal Revenue Service (“IRS”) deferral limitations. The Company makes contributions to the 401(k) Plan based on employee compensation and contributions. The Company matches 50 percent of each employee’s contribution up to 6 percent of their annual compensation. The Company recognized $12.7 million, $14.9 million and $15.2 million of expense for the years ended December 31, 2017, 2018 and 2019, respectively, for matching contributions to the 401(k) Plan.

Long Term Debt, Capital Lease a

Long Term Debt, Capital Lease and Deferred Financing Obligations	12 Months Ended
	Dec. 31, 2019
Long Term Debt, Capital Lease and Deferred Financing Obligations
Long Term Debt, Capital Lease and Deferred Financing Obligations	5. Long-Term Debt, Finance Lease and Deferred Financing Obligations Senior Notes The Notes bear interest payable semiannually in cash in arrears on March 22 and September 22 of each year, commencing on March 22, 2018, which rate is subject to an interest rate adjustment upon the occurrence of certain credit rating events. The Notes mature on September 22, 2024. The Indenture provides that the Notes are redeemable at the Company’s option, in whole or in part, at any time on or after July 22, 2024, at a redemption price equal to 100% of the principal amount of the Notes being redeemed plus accrued and unpaid interest thereon to, but excluding, the redemption date. The Indenture also contains certain covenants which restrict the Company’s ability to, among other things, create liens on its and its subsidiaries’ assets; engage in sale and lease-back transactions; and engage in a consolidation, merger or sale of assets. Credit Agreement On September 22, 2017, the Company entered into a credit agreement with various lenders that provides for a $400.0 million senior unsecured revolving credit facility and a $350.0 million senior unsecured term loan facility to the Company, as the borrower (the “2017 Credit Agreement”). On August 13, 2018, the Company entered into an amendment to the 2017 Credit Agreement, which extended the maturity date by one year Under the 2017 Credit Agreement, the annual interest rate on the loan borrowing is equal to (i) in the case of base rate loans, the sum of an initial borrowing margin of 0.500 percent plus the higher of the prime rate, one As of December 31, 2019, the contractual maturities of the term loan under the 2017 Credit Agreement were as follows: 2020—$0.0 million; 2021—$5.0 million; 2022—$17.5 million; and 2023—$258.1 million. At December 31, 2018 and 2019, the Company had no revolving loan borrowings, resulting in a borrowing capacity of $400.0 million under the 2017 Credit Agreement. Included in long-term debt and finance lease and deferred financing obligations as of December 31, 2018 and 2019 are deferred loan issuance costs of $5.9 million and $5.7 million, respectively. The 2017 Credit Agreement contains covenants that limit management’s discretion in operating the Company’s business by restricting or limiting the Company’s ability, among other things, to: ● incur or guarantee additional indebtedness or issue preferred or redeemable stock; ● pay dividends and make other distributions; ● repurchase equity interests; ● make certain advances, investments and loans; ● enter into sale and leaseback transactions; ● create liens; ● sell and otherwise dispose of assets; ● acquire or merge or consolidate with another company; and ● enter into some types of transactions with affiliates. Letter of Credit Agreement Finance Lease and Deferred Financing Obligations There were $31.2 million and $18.1 million of finance lease and deferred financing obligations at December 31, 2018 and December 31, 2019, respectively. The Company’s finance lease and deferred financing obligations represent amounts due under leases for certain properties, computer software (acquired prior to the prospective adoption of ASU 2015-05 on January 1, 2016) and equipment. The recorded gross cost of finance leased assets was $51.9 million and $56.0 million at December 31, 2018 and 2019, respectively.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2019
Stockholders' Equity
Stockholders' Equity	6. Stockholders’ Equity Stock Compensation At December 31, 2018 and 2019, the Company had equity-based employee incentive plans. Prior to May 18, 2016, the Company utilized the 2011 Management Incentive Plan (the “2011 MIP”), 2008 Management Incentive Plan (the “2008 MIP”) and 2006 Directors’ Equity Compensation Plan (collectively the “Preexisting Plans”) for grants of stock options, RSAs, RSUs, and stock appreciation rights, to provide incentives to officers, employees and non-employee directors. On February 25, 2016, the board of directors of the Company approved the 2016 Management Incentive Plan (“2016 MIP”), and the 2016 MIP was approved by the Company’s shareholders at the 2016 Annual Meeting of Shareholders on May 18, 2016. The 2016 MIP provides for the delivery of up to a number of shares equal to (i) 4,000,000 shares of common stock, plus (ii) the number of shares subject to outstanding awards under the 2011 MIP and Preexisting Plans which become available after shareholder approval of the 2016 MIP as a result of forfeitures, expirations, and in other permitted ways under the share recapture provisions of the 2016 MIP. Delivery of shares under “full-value” awards (awards other than options or stock appreciation rights) will be counted for each share delivered as 1.60 shares against the total number of shares reserved under the 2016 MIP. The 2016 MIP provides for awards of stock options, RSAs, RSUs, performance-based restricted stock units (“PSUs”), stock appreciation rights, cash-denominated awards and any combination of the foregoing. A RSU is a notional account representing the right to receive a share of the Company’s Common Stock (or, at the Company’s option, cash in lieu thereof) at some future date. In general, stock options vest ratably on each anniversary over the three years subsequent to grant, and have a ten year life. With the exception of the shares received by the principal owners of Partners Rx, CDMI and AFSC, RSAs generally vest on the anniversary of the grant. In general, RSUs vest ratably on each anniversary over the three years subsequent to grant. The PSUs vest over three years and are subject to market-based conditions. At December 31, 2019, 2,599,420 shares of the Company’s common stock remain available for future grant under the Company’s 2016 MIP. On February 27, 2014 the board of directors of the Company approved the 2014 Employee Stock Purchase Plan (“2014 ESPP”), and the 2014 ESPP was approved by the Company’s shareholders at the 2014 Annual Meeting of Shareholders on May 21, 2014. The 2014 ESPP provides for up to 200,000 shares of the Company’s common stock, plus the number of shares remaining under the 2011 Employee Stock Purchase Plan, to be issued. On May 24, 2018, the Company’s shareholders approved an amendment to the 2014 ESPP to increase by 300,000 the number of shares available for issuance under the plan. During the years ended December 31, 2018 and 2019, 63,471 and 93,632 shares of the Company’s common stock were issued under the employee stock purchase plans, respectively. At December 31, 2019, 215,084 shares of the Company’s common stock remain available for future grant under the Company’s 2014 ESPP. Stock Options Summarized information related to the Company’s stock options for the years ended December 31, 2017, 2018 and 2019 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 ​ 2018 ​ ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ ​ Exercise ​ ​ ​ Exercise ​ Options Price Options Price Outstanding, beginning of period 2,843,177 $ 57.42 2,458,237 $ 61.50 ​ Granted 525,596 ​ 71.35 477,956 ​ 96.39 ​ Forfeited (79,350) ​ 61.39 (174,376) ​ 80.21 ​ Exercised (831,186) ​ 53.79 (409,208) ​ 56.36 ​ Outstanding, end of period 2,458,237 ​ ​ 61.50 2,352,609 ​ ​ 68.10 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ ​ Weighted ​ Remaining ​ Aggregate ​ ​ ​ ​ ​ Average ​ Contractual ​ Intrinsic ​ ​ ​ ​ ​ Exercise ​ Term ​ Value ​ Options Price (in years) (in thousands) Outstanding, beginning of period 2,352,609 ​ $ 68.10 ​ ​ Granted 429,124 ​ ​ 66.22 ​ ​ ​ ​ ​ ​ Forfeited (112,120) ​ 78.18 ​ ​ ​ ​ ​ ​ Exercised (543,752) ​ 60.16 ​ ​ ​ ​ ​ ​ Outstanding, end of period 2,125,861 ​ $ 69.22 5.13 ​ $ 26,773 ​ Vested and expected to vest at end of period 2,116,787 ​ $ 69.20 5.12 ​ $ 26,689 ​ Exercisable, end of period 1,607,321 ​ $ 67.18 3.99 ​ $ 22,470 ​ ​ The aggregate intrinsic value in the table above represents the total pre-tax intrinsic value (based upon the difference between the Company’s closing stock price on the last trading day of 2019 of $77.87 and the exercise price) for all in-the-money options as of December 31, 2019. This amount changes based on the fair market value of the Company’s common stock. The total pre-tax intrinsic value of options exercised during the years ended December 31, 2017, 2018 and 2019 was $23.8 million, $17.3 million and $5.6 million, respectively. The weighted average grant date fair value per share of substantially all stock options granted during the years ended December 31, 2017, 2018 and 2019 was $17.64, $25.34 and $20.64 respectively, as estimated using the Black-Scholes-Merton option pricing model based on the following weighted average assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Risk-free interest rate 1.79 % 2.54 % 2.50 % Expected life 4 years 4 years 4 years Expected volatility 27.75 % 28.20 % 35.56 % Expected dividend yield 0.00 % 0.00 % 0.00 % ​ For the years ended December 31, 2017, 2018 and 2019, expected volatility was based on the historical volatility of the Company’s stock price. In the year ended December 31, 2017, the net tax benefit from excess tax deductions was $5.6 million, which consists of $5.7 million of excess tax benefits offset by $0.1 million of tax deficiencies. In the year ended December 31, 2018, the net tax benefit from excess tax deductions was $5.1 million and tax deficiencies were insignificant. In the year ended December 31, 2019, the net tax expense from tax deficiencies was $1.5 million, which consists of $1.8 million of tax deficiencies offset by $0.3 million of excess tax deductions. Restricted Stock Awards Summarized information related to the Company’s nonvested RSAs for the years ended December 31, 2017, 2018 and 2019 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 ​ 2018 ​ 2019 ​ ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ Shares Fair Value Shares Fair Value Shares Fair Value Outstanding, beginning of period 615,472 $ 58.71 31,102 $ 68.00 11,795 ​ $ 89.05 ​ Awarded 14,959 ​ 70.20 11,795 ​ 89.05 41,905 ​ 65.60 ​ Vested (585,438) ​ 58.33 (31,102) ​ 68.00 (13,939) ​ 85.99 ​ Forfeited (13,891) ​ 65.97 — ​ — — ​ — ​ Outstanding, ending of period 31,102 ​ ​ 68.00 11,795 ​ ​ 89.05 39,761 ​ ​ 65.40 ​ ​ As of December 31, 2019, there was $1.5 million of unrecognized stock compensation expense related to nonvested restricted stock awards. This cost is expected to be recognized over a weighted average period of 0.59 years. ​ Restricted Stock Units Summarized information related to the Company’s nonvested RSUs for the years ended December 31, 2017, 2018 and 2019 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 ​ 2018 ​ 2019 ​ ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ Shares Fair Value Shares Fair Value Shares Fair Value Outstanding, beginning of period 200,178 $ 61.65 163,289 $ 66.46 156,750 ​ $ 86.68 ​ Awarded 107,417 ​ 68.53 111,033 ​ 99.29 212,065 ​ 67.92 ​ Vested (119,489) ​ 60.38 (84,627) ​ 65.20 (68,993) ​ 81.95 ​ Forfeited (24,817) ​ 65.87 (32,945) ​ 84.17 (43,392) ​ 76.71 ​ Outstanding, ending of period ​ 163,289 ​ ​ 66.46 156,750 ​ ​ 86.68 256,430 ​ ​ 74.12 ​ ​ As of December 31, 2019, there was $12.6 million of unrecognized stock compensation expense related to nonvested restricted stock units. This cost is expected to be recognized over a weighted average period of 2.01 years. Performance-Based Restricted Stock Units Summarized information related to the Company’s nonvested PSUs for the years ended December 31, 2017, 2018 and 2019 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Weighted ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ ​ Shares ​ Fair Value ​ Shares ​ Fair Value ​ Shares ​ Fair Value Outstanding, beginning of period ​ 102,977 ​ $ 93.03 ​ 202,315 ​ $ 84.63 ​ 209,019 ​ $ 103.38 ​ Awarded ​ 101,989 ​ 76.24 ​ 80,502 ​ 141.61 ​ 101,498 ​ 101.82 ​ Vested ​ — ​ — ​ (33,592) ​ 85.00 ​ (43,109) ​ 97.12 ​ Forfeited ​ (2,651) ​ 87.75 ​ (40,206) ​ 100.96 ​ (18,849) ​ 97.49 ​ Outstanding, end of period ​ 202,315 ​ 84.63 ​ 209,019 ​ 103.38 ​ 248,559 ​ 104.27 ​ ​ The PSUs will entitle the grantee to receive a number of shares of the Company’s Common Stock determined over a three-year performance period ending on December 31 of the year prior to the settlement date of the awards, provided the grantee remains in the service of the Company on the settlement date. The Company expenses the cost of PSU awards ratably over the requisite service period. The number of shares for which the PSUs will be settled will be a percentage of shares for which the award is targeted and will depend on the Company’s total shareholder return (as defined below), expressed as a percentile ranking of the Company’s total shareholder return as compared to the Company’s peer group (as defined below). The number of shares for which the PSUs will be settled vary from zero to 200 percent of the shares specified in the grant. Total shareholder return is determined by dividing the average share value of the Company’s Common Stock over the 30 trading days preceding January 1 of the year the awards are scheduled to vest by the average share value of the Company’s Common Stock over the 30 trading days beginning on January 1 of the year the awards were granted, with a deemed reinvestment of any dividends declared during the performance period. The Company’s peer group includes companies which comprise the S&P Health Care Services Industry Index, selected by the Compensation Committee of the Company’s Board of Directors and includes a range of healthcare companies operating in several business segments. The weighted average estimated fair value of the PSUs granted in the year ended December 31, 2017 was $76.24, which was derived from a Monte Carlo simulation. Significant assumptions utilized in estimating the value of the awards granted include an expected dividend yield of 0%, a risk-free rate of 1.54%, and expected volatility of 18% to 61% (average of 33%). The weighted average estimated fair value of the PSUs granted in the year ended December 31, 2018 was $141.61, which was derived from a Monte Carlo simulation. Significant assumptions utilized in estimating the value of the awards granted include an expected dividend yield of 0%, a risk-free rate of 2.37%, and expected volatility of 20% to 82% (average of 35%). The weighted average estimated fair value of the PSUs granted in the year ended December 31, 2019 was $101.82, which was derived from a Monte Carlo simulation. Significant assumptions utilized in estimating the value of the awards granted include an expected dividend yield of 0%, a risk-free rate of 2.35%, and expected volatility of 58% to 82% (average of 78%). As of December 31, 2019, there was Net Income per Common Share Attributable to Magellan The following table reconciles income (numerator) and shares (denominator) used in the Company’s computations of net income per share for the years ended December 31, 2017, 2018 and 2019 (in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 ​ Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income ​ $ 110,207 ​ $ 24,181 ​ $ 55,902 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of common shares outstanding—basic ​ 23,333 ​ 24,349 ​ 24,243 ​ Common stock equivalents—stock options ​ 530 ​ 493 ​ 142 ​ Common stock equivalents—RSAs ​ 376 ​ 15 ​ 8 ​ Common stock equivalents—RSUs ​ 64 ​ 37 ​ 35 ​ Common stock equivalents—PSUs ​ ​ 134 ​ ​ 137 ​ ​ 131 ​ Common stock equivalents—employee stock purchase plan ​ 3 ​ 4 ​ 4 ​ Weighted average number of common shares outstanding—diluted ​ 24,440 ​ 25,035 ​ 24,563 ​ Net income per common share—basic ​ $ 4.72 ​ $ 0.99 ​ $ 2.31 ​ Net income per common share—diluted ​ $ 4.51 ​ $ 0.97 ​ $ 2.28 ​ ​ The weighted average number of common shares outstanding for the years ended December 31, 2017, 2018 and 2019 was calculated using outstanding shares of the Company’s common stock. Common stock equivalents included in the calculation of diluted weighted average common shares outstanding for the years ended December 31, 2017, 2018 and 2019 represent stock options to purchase shares of the Company’s common stock, restricted stock awards, restricted stock units and stock purchased under the 2014 ESPP. For the years ended December 31, 2017, 2018 and 2019, the Company had additional potential dilutive securities outstanding representing 0.4 million, 0.5 million and 1.0 million options, respectively, that were not included in the computation of dilutive securities because they were anti-dilutive for such periods. Had these shares not been anti-dilutive, all of these shares would not have been included in the net income per common share calculation, as the Company uses the treasury stock method of calculating diluted shares. Stock Repurchases The Company’s board of directors has previously authorized a series of stock repurchase plans. Stock repurchases for each such plan could be executed through open market repurchases, privately negotiated transactions, accelerated share repurchases or other means. The board of directors authorized management to execute stock repurchase transactions from time to time and in such amounts and via such methods as management deemed appropriate. Each stock repurchase program could be limited or terminated at any time without prior notice. On October 26, 2015, the Company’s board of directors approved a stock repurchase plan which authorized the Company to purchase up to $200 million of its outstanding common stock through October 22, 2017. On July 26, 2017, the Company’s board of directors approved an extension of the 2015 Repurchase Program through October 22, 2018. On May 24, 2018, the Company’s board of directors approved an increase of $200 million to the current $200 million stock repurchase plan which now authorizes the Company to purchase up to $400 million of its outstanding common stock under the 2015 Repurchase Program. The board also extended the program from October 22, 2018 to October 22, 2020. As of December 31, 2019, the remaining capacity under the 2015 Repurchase Program was $186.3 million. Pursuant to this program, the Company made purchases as follows (aggregate cost excludes broker commissions and is reflected in millions): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Number ​ Average ​ ​ ​ ​ ​ ​ of Shares ​ Price Paid ​ Aggregate ​ Period Purchased per Share Cost October 26, 2015 - December 31, 2015 ​ 345,044 ​ $ 53.46 ​ $ 18.4 ​ January 1, 2016 - December 31, 2016 ​ 1,828,183 ​ ​ 58.40 ​ ​ 106.8 ​ January 1, 2017 - December 31, 2017 ​ 280,140 ​ ​ 77.67 ​ ​ 21.8 ​ January 1, 2018 - December 31, 2018 ​ 844,872 ​ ​ 74.59 ​ ​ 63.0 ​ January 1, 2019 - December 31, 2019 ​ 60,901 ​ ​ 61.15 ​ ​ 3.7 ​ ​ ​ 3,359,140 ​ ​ ​ ​ $ 213.7 ​

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Taxes
Income Taxes	7. Income Taxes Income Tax Expense The components of income tax expense (benefit) for the following years ended December 31 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Income taxes currently payable: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ $ 49,944 ​ $ 13,593 ​ $ 13,144 ​ State ​ 6,120 ​ 7,145 ​ 4,719 ​ ​ ​ 56,064 ​ 20,738 ​ 17,863 ​ Deferred income taxes (benefits): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ (31,941) ​ 307 ​ 6,061 ​ State ​ 960 ​ (2,032) ​ 991 ​ ​ ​ (30,981) ​ (1,725) ​ 7,052 ​ Total income tax expense ​ $ 25,083 ​ $ 19,013 ​ $ 24,915 ​ ​ ​ Total income tax expense for the years ended December 31 was different from the amount computed using the statutory federal income tax rate in effect for each respective year for the following reasons (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Income tax expense at federal statutory rate ​ $ 47,328 ​ $ 9,071 ​ $ 16,972 ​ State income taxes, net of federal income tax benefit ​ 4,993 ​ 2,968 ​ 4,761 ​ State contingencies added ​ ​ 2,161 ​ ​ 3,644 ​ ​ 1,178 ​ Tax contingencies reversed due to statute closings ​ (2,044) ​ (2,651) ​ (3,115) ​ Change in valuation allowances ​ ​ (14,973) ​ ​ (691) ​ ​ 584 ​ Adjustments for Tax Act ​ ​ (8,677) ​ ​ 335 ​ ​ — ​ Share-based compensation ​ ​ (4,724) ​ ​ (4,750) ​ ​ 1,737 ​ Qualified research credit ​ ​ (1,325) ​ ​ (1,781) ​ ​ (1,594) ​ Non-deductible executive compensation ​ ​ 104 ​ ​ 3,052 ​ ​ 3,153 ​ Non-deductible HIF fees ​ ​ — ​ ​ 8,246 ​ ​ — ​ Other-net ​ 2,240 ​ 1,570 ​ 1,239 ​ Total income tax expense ​ $ 25,083 ​ $ 19,013 ​ $ 24,915 ​ ​ Tax Cuts and Jobs Act (the “Tax Act”) enacted on December 22, 2017 included several changes to existing U.S. tax laws that impact the Company, including a reduction of the U.S. corporate income tax rate from 35 percent to 21 percent, effective January 1, 2018, and additional limitations on the deduction of executive compensation. Deferred Income Taxes The significant components of deferred tax assets and liabilities at December 31 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 2019 Deferred tax assets: ​ ​ ​ ​ ​ ​ ​ Net operating loss carryforwards ​ $ 11,159 ​ $ 8,417 ​ Share-based compensation ​ 10,299 ​ 9,167 ​ Other accrued compensation ​ 5,508 ​ 10,697 ​ Claims reserves ​ 7,053 ​ 5,355 ​ Deferred revenue ​ ​ 4,368 ​ ​ 4,122 ​ Other non-deductible accrued liabilities ​ 6,057 ​ 3,267 ​ Indirect tax benefits ​ ​ 3,296 ​ ​ 3,011 ​ Operating lease--right-of-use liabilities ​ ​ — ​ ​ 18,632 ​ Other deferred tax assets ​ 2,130 ​ 111 ​ Total deferred tax assets ​ 49,870 ​ 62,779 ​ Valuation allowances ​ (1,521) ​ (2,105) ​ Deferred tax assets after valuation allowances ​ 48,349 ​ 60,674 ​ Deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ Depreciation ​ (21,350) ​ (20,577) ​ Amortization of goodwill and intangible assets ​ ​ (30,463) ​ ​ (33,073) ​ Operating lease--right-of-use assets ​ ​ — ​ ​ (16,656) ​ Other deferred tax liabilities ​ (4,292) ​ (5,562) ​ Total deferred tax liabilities ​ (56,105) ​ (75,868) ​ Net deferred tax liabilities ​ $ (7,756) ​ $ (15,194) ​ ​ The Company has $16.2 million of federal net operating loss carryforwards (“NOLs”) available to reduce consolidated taxable income in 2020 and subsequent years. These NOLs were incurred by AlphaCare prior to its membership in the Magellan consolidated group and will expire in 2032 through 2035 if not used. Further, these NOLs are subject to examination and adjustment by the IRS. In addition, the Company’s utilization of these NOLs is subject to limitations under the Internal Revenue Code as to the timing and use. At this time, the Company does not believe these limitations will restrict the Company’s ability to use any federal NOLs before they expire. The Company and its subsidiaries also have $88.6 million of NOLs available to reduce state and local taxable income at certain subsidiaries in 2020 and subsequent years. These NOLs are subject to examination and adjustment by the respective tax authorities, and most will expire in 2020 through 2039 if not used. In addition, the Company’s utilization of certain of these NOLs is subject to limitations as to the timing and use. The Company’s valuation allowances against deferred tax assets were $1.5 million and $2.1 million as of December 31, 2018 and 2019, respectively. The change in valuation allowance of $0.6 million was reflected as an increase to income tax expense. These allowances primarily relate to uncertainties regarding the eventual realization of certain state NOLs. Uncertain Tax Positions A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Balance as of beginning of period ​ $ 13,604 ​ $ 13,580 ​ $ 15,683 ​ Additions for current year tax positions ​ 3,243 ​ 4,955 ​ 1,492 ​ Additions for tax positions of prior years ​ 342 ​ 512 ​ 699 ​ Reductions for tax positions of prior years ​ (114) ​ (398) ​ (472) ​ Reductions due to lapses of applicable statutes of limitations ​ (2,693) ​ (3,005) ​ (3,489) ​ Changes due to Tax Act ​ ​ (509) ​ ​ 339 ​ ​ — ​ Reductions due to settlements with taxing authorities ​ (293) ​ (300) ​ (43) ​ Balance as of end of period ​ $ 13,580 ​ $ 15,683 ​ $ 13,870 ​ ​ If these unrecognized tax benefits had been realized as of December 31, 2018 and 2019, $12.3 million and $10.9 million, respectively, would have reduced income tax expense. The Company continually performs a comprehensive review of its tax positions and accrues amounts for tax contingencies related to uncertain tax positions. Based upon these reviews, the status of ongoing tax audits and the expiration of applicable statutes of limitations, accruals are adjusted as necessary. The tax benefit from an uncertain tax position is recognized when it is more likely than not that, based on the technical merits, the position will be sustained upon examination, including resolution of any related appeals or litigation processes. The Company also adjusts these liabilities for unrecognized tax benefits when its judgment changes as a result of the evaluation of new information not previously available. However, the ultimate resolution of a disputed tax position following an examination by a taxing authority could result in a payment that is materially different from that accrued by the Company. These differences are typically reflected as increases or decreases to income tax expense in the period in which they are determined. The statutes of limitations regarding the assessment of federal and most state and local income taxes for 2015 expired during 2019. As a result, $3.5 million of tax contingency reserves recorded as of December 31, 2018 were reversed in 2019, of which $2.8 million was reflected as a reduction to income tax expense and $0.7 million as a decrease to deferred tax assets. Additionally, $0.3 million of accrued interest was reversed in 2019 and reflected as a reduction to income tax expense due to the closing of statutes of limitations on tax assessments. The statutes of limitations regarding the assessment of federal and most state and local income taxes for 2014 expired during 2018. As a result, $3.0 million of tax contingency reserves recorded as of December 31, 2017 were reversed in 2018, of which $2.4 million was reflected as a reduction to income tax expense and $0.6 million as a decrease to deferred tax assets. Additionally, $0.2 million of accrued interest was reversed in 2018 and reflected as a reduction to income tax expense due to the closing of statutes of limitations on tax assessments. The statutes of limitations regarding the assessment of federal and most state and local income taxes for 2013 expired during 2017. As a result, $3.0 million of tax contingency reserves recorded as of December 31, 2016 were reversed in 2017, of which $2.0 million was reflected as a reduction to income tax expense and $1.0 million as a decrease to deferred tax assets. Additionally, $0.2 million of accrued interest was reversed in 2017 and reflected as a reduction to income tax expense due to the closing of statutes of limitations on tax assessments. With few exceptions, the Company is no longer subject to income tax assessments by tax authorities for years ended prior to 2016. Further, it is reasonably possible the statutes of limitations regarding the assessment of federal and most state and local income taxes for 2016 could expire during 2020. Up to $3.4 million of unrecognized tax benefits recorded as of December 31, 2019 could be reversed during 2020 as a result of statute expirations, of which $2.7 million would be reflected as a reduction to income tax expense and $0.7 million as a decrease to deferred tax assets. All reversals from statute expirations would be reflected as discrete adjustments during the quarter in which the respective event occurs. As of December 31, 2018 and 2019, the Company had accrued approximately $0.6 million and $0.7 million, respectively, for the potential payment of interest and penalties. The Company accrues interest and penalties related to unrecognized tax benefits in its provision for income taxes. During the years ended December 31, 2017, 2018 and 2019, the Company recorded approximately $0.2 million, $0.1 million and $0.1 million, respectively, in interest and penalties.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Information
Supplemental Cash Flow Information	8. Supplemental Cash Flow Information Supplemental cash flow information for the years ended December 31, 2017, 2018 and 2019 is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Income taxes paid, net of refunds ​ $ 59,474 ​ $ 40,179 ​ $ 4,774 ​ Interest paid ​ $ 15,415 ​ $ 34,223 ​ $ 29,892 ​ Assets acquired through capital leases and deferred financing ​ $ 2,418 ​ $ 20,576 ​ $ 3,302 ​ ​

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies
Commitments and Contingencies	9. Commitments and Contingencies Insurance The Company maintains a program of insurance coverage for a broad range of risks in its business. The Company has renewed its general, professional and managed care liability insurance policies with unaffiliated insurers for a one-year The Company maintains a separate general and professional liability insurance policy with an unaffiliated insurer for its specialty pharmaceutical dispensing operations. The specialty pharmaceutical dispensing operations insurance policy has a one-year The Company is responsible for claims within its self-insured retentions, and for portions of claims reported after the expiration date of the policies if they are not renewed, or if policy limits are exceeded. The Company also purchases excess liability coverage in an amount that management believes to be reasonable for the size and profile of the organization. Regulatory Issues The managed healthcare industry is subject to numerous laws and regulations. The subjects of such laws and regulations cover, but are not limited to, matters such as licensure, accreditation, government healthcare program participation requirements, information privacy and security, reimbursement for patient services, and Medicare and Medicaid fraud and abuse. Over the past several years, government activity has increased with respect to investigations and/or allegations concerning possible violations of fraud and abuse and false claims statutes and/or regulations by healthcare organizations and insurers. Entities that are found to have violated these laws and regulations may be excluded from participating in government healthcare programs, subjected to fines or penalties or required to repay amounts received from the government for previously billed patient services. Compliance with such laws and regulations can be subject to future government review and interpretation, as well as regulatory actions unknown or unasserted at this time. In addition, regulators of certain of the Company’s subsidiaries may exercise certain discretionary rights under regulations including increasing their supervision of such entities, requiring additional restricted cash or other security or seizing or otherwise taking control of the assets and operations of such subsidiaries. The Company is subject to certain federal laws and regulations in connection with its contracts with the federal government. These laws and regulations affect how the Company conducts business with its federal agency customers and may impose added costs on its business. The Company’s failure to comply with federal procurement laws and regulations could cause it to lose business, incur additional costs and subject it to a variety of civil and criminal penalties and administrative sanctions, including termination of contracts, forfeiture of profits, harm to reputation, suspension of payments, fines, and suspension or debarment from doing business with federal government agencies. The Company’s wholly owned subsidiary, AFSC, conducts business with federal agency customers and federal contractors to such agencies. The Company is investigating, with the assistance of outside counsel, matters relating to compliance by AFSC with Small Business Administration ( “SBA”) regulations and other federal laws applicable to government contractors and has reported findings to the SBA and the Department of Defense, including facts indicating violations of SBA regulations and other federal laws, such as the Anti-Kickback Act, by former AFSC executives, none of which was disclosed to Magellan prior to its acquisition of AFSC. The Company is voluntarily responding to government requests for further information regarding the Company’s investigation. Contingencies, if any, arising from the results of this investigation and self-reporting could require us to record balance sheet liabilities or accrue expenses, the amount of which we are not able to currently estimate. While the Company believes that it has responded appropriately by self-reporting findings regarding matters that incepted prior to its acquisition of AFSC in order to mitigate the risk of adverse consequences, should the SBA, Department of Defense and/or other federal agencies seek to hold the Company or AFSC responsible for the reported conduct, we may be required to pay damages and/or penalties and AFSC could be suspended or debarred from government contracting. For 2018 and 2019 AFSC’s total revenue comprised approximately 2% of the total revenues of the Company. ​ Legal The Company’s operating activities entail significant risks of liability. From time to time, the Company is subject to various actions and claims arising from the acts or omissions of its employees, network providers or other parties. In the normal course of business, the Company receives reports relating to deaths and other serious incidents involving patients whose care is being managed by the Company. Such incidents occasionally give rise to malpractice, professional negligence and other related actions and claims against the Company or its network providers. Many of these actions and claims received by the Company seek substantial damages and therefore require the Company to incur significant fees and costs related to their defense. Leases The Company leases certain office space, distribution centers, land and equipment. These leases expire at various dates through August 2027. See Note 2—“Summary of Significant Accounting Policies—Leases” for a discussion of the Company’s leases.

Business Segment Information

Business Segment Information	12 Months Ended
	Dec. 31, 2019
Business Segment Information
Business Segment Information	10. Business Segment Information The accounting policies of the Company’s segments are the same as those described in Note 2—“Summary of Significant Accounting Policies.” The Company evaluates performance of its segments based on profit or loss from operations before stock compensation expense, depreciation and amortization, interest expense, interest and other income, changes in the fair value of contingent consideration recorded in relation to acquisitions, gain on sale of assets, special charges or benefits, and income taxes (“Segment Profit”). Management uses Segment Profit information for internal reporting and control purposes and considers it important in making decisions regarding the allocation of capital and other resources, risk assessment and employee compensation, among other matters. Healthcare subcontracts with Pharmacy Management to provide pharmacy benefits management services for certain of Healthcare’s customers. In addition, Pharmacy Management provides pharmacy benefits management for the Company’s employees covered under its medical plan. As such, revenue, cost of goods sold and direct service costs and other related to these arrangements are eliminated. The Company’s segments are defined in Note 1—“General.” The following tables summarize, for the periods indicated, operating results by business segment for the years ended December 31, 2017, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate ​ ​ ​ ​ ​ ​ ​ Pharmacy ​ and ​ ​ ​ ​ Healthcare Management Elimination Consolidated Year Ended December 31, 2017 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Managed care and other revenue ​ $ 3,206,277 ​ $ 273,489 ​ $ (584) ​ $ 3,479,182 ​ PBM and dispensing revenue ​ — ​ 2,491,044 ​ (131,643) ​ 2,359,401 ​ Cost of care ​ (2,413,770) ​ — ​ — ​ (2,413,770) ​ Cost of goods sold ​ — ​ (2,341,979) ​ 130,069 ​ (2,211,910) ​ Direct service costs and other ​ (601,201) ​ (302,525) ​ (38,157) ​ (941,883) ​ Stock compensation expense (1) ​ ​ 10,689 ​ ​ 19,881 ​ ​ 8,546 ​ ​ 39,116 ​ Changes in fair value of contingent consideration (1) ​ ​ 696 ​ ​ — ​ ​ — ​ ​ 696 ​ Less: non-controlling interest segment loss (2) ​ (56) ​ — ​ (3) ​ (59) ​ Segment profit (loss) ​ $ 202,747 ​ $ 139,910 ​ $ (31,766) ​ $ 310,891 ​ Identifiable assets by business segment (3) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Restricted cash ​ $ 220,786 ​ $ 8,059 ​ $ 168 ​ $ 229,013 ​ Net accounts receivable ​ 244,486 ​ 403,880 ​ 12,409 ​ 660,775 ​ Investments ​ 327,865 ​ — ​ — ​ 327,865 ​ Pharmaceutical inventory ​ — ​ 40,945 ​ — ​ 40,945 ​ Goodwill ​ 610,867 ​ 395,421 ​ — ​ 1,006,288 ​ Other intangible assets, net ​ 165,159 ​ 103,129 ​ — ​ 268,288 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate ​ ​ ​ ​ ​ ​ ​ Pharmacy ​ and ​ ​ ​ ​ Healthcare Management Elimination Consolidated Year Ended December 31, 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Managed care and other revenue ​ $ 4,638,622 ​ $ 240,427 ​ $ (607) ​ $ 4,878,442 ​ PBM revenue ​ — ​ 2,625,417 ​ (189,708) ​ 2,435,709 ​ Cost of care ​ (3,762,412) ​ — ​ — ​ (3,762,412) ​ Cost of goods sold ​ — ​ (2,468,170) ​ 185,148 ​ (2,283,022) ​ Direct service costs and other ​ (735,366) ​ (298,713) ​ (37,456) ​ (1,071,535) ​ Stock compensation expense (1) ​ 6,982 ​ 5,458 ​ 17,032 ​ 29,472 ​ Changes in fair value of contingent consideration (1) ​ ​ 1,307 ​ ​ — ​ ​ — ​ ​ 1,307 ​ Segment Profit (Loss) ​ $ 149,133 ​ $ 104,419 ​ $ (25,591) ​ $ 227,961 ​ Identifiable assets by business segment (3) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Restricted cash ​ $ 157,437 ​ $ 576 ​ $ 2,954 ​ $ 160,967 ​ Net accounts receivable ​ 290,564 ​ 465,345 ​ 150 ​ 756,059 ​ Investments ​ 378,706 ​ 7,037 ​ — ​ 385,743 ​ Pharmaceutical inventory ​ — ​ 40,818 ​ — ​ 40,818 ​ Goodwill ​ 622,604 ​ 395,552 ​ — ​ 1,018,156 ​ Other intangible assets, net ​ 136,644 ​ 82,072 ​ 13,167 ​ 231,883 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate ​ ​ ​ ​ ​ ​ ​ Pharmacy ​ and ​ ​ ​ ​ Healthcare Management Elimination Consolidated Year Ended December 31, 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Managed care and other revenue ​ $ 4,838,546 ​ $ 265,439 ​ $ (592) ​ $ 5,103,393 ​ PBM revenue ​ — ​ 2,236,829 ​ (180,799) ​ 2,056,030 ​ Cost of care ​ (3,940,531) ​ — ​ — ​ (3,940,531) ​ Cost of goods sold ​ — ​ (2,076,509) ​ 177,638 ​ (1,898,871) ​ Direct service costs and other ​ (726,937) ​ (323,162) ​ (40,632) ​ (1,090,731) ​ Stock compensation expense (1) ​ 8,467 ​ 7,834 ​ 9,200 ​ 25,501 ​ Changes in fair value of contingent consideration (1) ​ ​ (2,124) ​ ​ — ​ ​ — ​ ​ (2,124) ​ Segment Profit (Loss) ​ $ 177,421 ​ $ 110,431 ​ $ (35,185) ​ $ 252,667 ​ Identifiable assets by business segment (3) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Restricted cash ​ $ 144,229 ​ $ 2,226 ​ $ — ​ $ 146,455 ​ Net accounts receivable ​ 410,958 ​ 478,627 ​ 480 ​ 890,065 ​ Investments ​ 338,439 ​ 6,718 ​ — ​ 345,157 ​ Pharmaceutical inventory ​ — ​ 44,962 ​ — ​ 44,962 ​ Goodwill ​ 622,604 ​ 395,552 ​ — ​ 1,018,156 ​ Other intangible assets, net ​ 105,728 ​ 61,536 ​ 80 ​ 167,344 ​ (1) Stock compensation expense, changes in the fair value of contingent consideration recorded in relation to the acquisitions and impairment of intangible assets are included in direct service costs and other operating expenses; however, these amounts are excluded from the computation of Segment Profit. (2) The non-controlling interest portion of AlphaCare’s segment loss is excluded from the computation of Segment Profit in 2017. (3) Identifiable assets by business segment are those assets that are used in the operations of each segment. The remainder of the Company’s assets cannot be specifically identified by segment. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 ​ Income before income taxes $ 135,224 ​ $ 43,194 ​ $ 80,817 ​ Stock compensation expense 39,116 ​ 29,472 ​ 25,501 ​ Changes in fair value of contingent consideration ​ 696 ​ ​ 1,307 ​ ​ (2,124) ​ Non-controlling interest segment loss ​ 59 ​ ​ — ​ ​ — ​ Depreciation and amortization 115,706 ​ 132,660 ​ 131,509 ​ Interest expense 25,977 ​ 35,396 ​ 36,153 ​ Interest and other income (5,887) ​ (14,068) ​ (19,189) ​ Segment Profit $ 310,891 ​ $ 227,961 ​ $ 252,667 ​ ​

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2019
Selected Quarterly Financial Data (Unaudited)
Selected Quarterly Financial Data (Unaudited)	11. Selected Quarterly Financial Data (Unaudited) The following is a summary of the unaudited quarterly results of operations for the years ended December 31, 2018 and 2019 (in thousands, except per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Quarter Ended ​ ​ March 31, ​ June 30, ​ September 30, ​ December 31, ​ 2018 2018 2018 2018 Year Ended December 31, 2018 ​ ​ ​ ​ ​ Net revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Managed care and other ​ $ 1,219,763 ​ $ 1,215,340 ​ $ 1,235,787 ​ $ 1,207,552 ​ PBM and dispensing ​ 585,314 ​ 595,583 ​ 617,719 ​ 637,093 ​ Total net revenue ​ 1,805,077 ​ 1,810,923 ​ 1,853,506 ​ 1,844,645 ​ Costs and expenses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of care ​ 928,661 ​ 935,814 ​ 938,031 ​ 959,906 ​ Cost of goods sold ​ 559,665 ​ 558,419 ​ 571,145 ​ 593,793 ​ Direct service costs and other operating expenses (1) (2) ​ 269,077 ​ 259,152 ​ 265,471 ​ 277,835 ​ Depreciation and amortization ​ 30,407 ​ 33,848 ​ 33,047 ​ 35,358 ​ Interest expense ​ 8,366 ​ 8,678 ​ 8,990 ​ 9,362 ​ Interest and other income ​ (2,476) ​ (3,363) ​ (4,139) ​ (4,090) ​ Total costs and expenses ​ 1,793,700 ​ 1,792,548 ​ 1,812,545 ​ 1,872,164 ​ Income (loss) before income taxes ​ 11,377 ​ 18,375 ​ 40,961 ​ (27,519) ​ Provision (benefit) for income taxes ​ (75) ​ 4,824 ​ 13,816 ​ 448 ​ Net income (loss) attributable to Magellan ​ $ 11,452 ​ $ 13,551 ​ $ 27,145 ​ $ (27,967) ​ Weighted average number of common shares outstanding—basic ​ 24,349 ​ ​ 24,569 ​ ​ 24,433 ​ ​ 24,048 ​ Weighted average number of common shares outstanding—diluted ​ 25,612 ​ ​ 25,407 ​ ​ 24,928 ​ ​ 24,048 ​ Net income (loss) per common share attributable to Magellan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) per common share—basic: ​ $ 0.47 ​ $ 0.55 ​ $ 1.11 ​ $ (1.16) ​ Net income (loss) per common share—diluted: ​ $ 0.45 ​ $ 0.53 ​ $ 1.09 ​ $ (1.16) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Quarter Ended ​ ​ March 31, ​ June 30, ​ September 30, ​ December 31, ​ 2019 2019 2019 2019 Year Ended December 31, 2019 ​ ​ ​ ​ ​ Net revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Managed care and other ​ $ 1,223,979 ​ $ 1,283,143 ​ $ 1,303,936 ​ $ 1,292,335 ​ PBM and dispensing ​ 515,510 ​ 505,193 ​ 525,005 ​ 510,322 ​ Total net revenue ​ 1,739,489 ​ 1,788,336 ​ 1,828,941 ​ 1,802,657 ​ Costs and expenses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of care ​ 941,961 ​ 1,001,886 ​ 1,013,006 ​ 983,678 ​ Cost of goods sold ​ 489,793 ​ 461,187 ​ 482,277 ​ 465,614 ​ Direct service costs and other operating expenses (3)(4) ​ 271,924 ​ 266,434 ​ 266,322 ​ 286,051 ​ Depreciation and amortization ​ 30,708 ​ 33,490 ​ 34,157 ​ 33,154 ​ Interest expense ​ 9,107 ​ 9,141 ​ 9,007 ​ 8,898 ​ Interest and other income ​ (4,974) ​ (5,021) ​ (4,970) ​ (4,224) ​ Total costs and expenses ​ 1,738,519 ​ 1,767,117 ​ 1,799,799 ​ 1,773,171 ​ Income before income taxes ​ 970 ​ 21,219 ​ 29,142 ​ 29,486 ​ Provision for income taxes ​ 539 ​ 7,606 ​ 7,868 ​ 8,902 ​ Net income attributable to Magellan ​ ​ 431 ​ ​ 13,613 ​ ​ 21,274 ​ ​ 20,584 ​ Weighted average number of common shares outstanding—basic ​ ​ 23,946 ​ ​ 24,101 ​ ​ 24,426 ​ ​ 24,491 ​ Weighted average number of common shares outstanding—diluted ​ ​ 24,213 ​ ​ 24,416 ​ ​ 24,708 ​ ​ 24,905 ​ Net income per common share attributable to Magellan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income per common share—basic: ​ $ 0.02 ​ $ 0.56 ​ $ 0.87 ​ $ 0.84 ​ Net income per common share—diluted: ​ $ 0.02 ​ $ 0.56 ​ $ 0.86 ​ $ 0.83 ​ ​ (1) Includes stock compensation expense of $7,646, $10,439 , $9,320 and $2,067 for the quarters ended March 31, June 30, September 30 and December 31, 2018, respectively. (2) Includes changes in fair value of contingent consideration of $233, $70, $148 and $856 for the quarters ended March 31, June 30, September 30 and December 31, 2018, respectively. (3) Includes stock compensation expense of $9,607, $5,414 , $4,811 and $5,669 for the quarters ended March 31, June 30, September 30 and December 31, 2019, respectively. (4) Includes changes in fair value of contingent consideration of $144, $(2,149), $4 and $(123) for the quarters ended March 31, June 30, September 30 and December 31, 2019, respectively.

SCHEDULE I - CONDENSED FINANCIA

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT	12 Months Ended
	Dec. 31, 2019
SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT
SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT	SCHEDULE I – CONDENSED FINANCIAL INFORMATION OF REGISTRANT MAGELLAN HEALTH, INC. (Parent Company Only) CONDENSED BALANCE SHEETS AS OF DECEMBER 31, (in thousands) ​ ​ ​ ​ ​ ​ ​ 2018 2019 ASSETS ​ ​ ​ ​ ​ Current Assets: ​ ​ ​ ​ ​ Cash and cash equivalents $ 2 ​ $ 2 Accounts receivable — ​ 7 Due from affiliates, net ​ 179,360 ​ ​ 52,629 Other current assets 32 ​ 32 Total Current Assets 179,394 ​ 52,670 Other long-term assets ​ 3,255 ​ ​ 26,789 Investment in subsidiaries ​ 1,832,258 ​ ​ 2,016,039 Total Assets $ 2,014,907 ​ $ 2,095,498 LIABILITIES AND STOCKHOLDERS’ EQUITY ​ ​ ​ ​ ​ Accounts Payable $ 399 ​ $ 200 Accrued liabilities ​ 7,555 ​ ​ 8,197 Current debt 16,400 ​ — Total Current Liabilities 24,354 ​ 8,397 Long-term debt 705,250 ​ 664,707 Deferred credits and other long-term liabilities — ​ 24,611 Total Liabilities 729,604 ​ 697,715 Preferred stock, par value $.01 per share ​ ​ ​ ​ ​ Authorized— 10,000 shares at December 31, 2018 and December 31, 2019- Issued and outstanding -none — ​ — Ordinary common stock, par value $.01 per share ​ ​ ​ ​ ​ Authorized—100,000 shares at December 31, 2018 and December 31, 2019-Issued and outstanding-53,536 and 23,935 shares at December 31, 2018, respectively, and 54,285 and 24,623 shares at December 31, 2019, respectively 535 ​ 543 Other Stockholders’ Equity: ​ ​ ​ ​ ​ Additional paid-in capital 1,326,645 ​ 1,386,616 Retained earnings 1,419,449 ​ 1,475,207 Accumulated other comprehensive loss (324) ​ 144 Treasury stock, at cost, 29,601 and 29,662 shares at December 31, 2018 and December 31, 2019, respectively (1,461,002) ​ (1,464,727) Total Stockholders’ Equity 1,285,303 ​ 1,397,783 Total Liabilities, Redeemable Non-Controlling Interest and Stockholders’ Equity $ 2,014,907 ​ $ 2,095,498 ​ See accompanying notes to condensed financial statements. ​ SCHEDULE I – CONDENSED FINANCIAL INFORMATION OF REGISTRANT MAGELLAN HEALTH, INC. (Parent Company Only) CONDENSED STATEMENTS OF COMPREHENSIVE INCOME FOR THE YEARS ENDED DECEMBER 31, (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Costs and expenses: ​ ​ ​ ​ ​ ​ ​ ​ Direct service costs and other operating expenses $ 38,157 ​ $ 37,456 ​ $ 40,632 Interest expense 8,343 ​ 33,258 ​ 34,964 Interest and other income (157) ​ (98) ​ — Total costs and expenses 46,343 ​ 70,616 ​ 75,596 Loss before income taxes (46,343) ​ (70,616) ​ (75,596) Benefit for income taxes 17,918 ​ 18,288 ​ 19,437 Net loss before equity in subsidiaries ​ (28,425) ​ ​ (52,328) ​ ​ (56,159) Equity in earnings from subsidiaries ​ 138,632 ​ ​ 76,509 ​ ​ 112,061 Net income ​ 110,207 ​ ​ 24,181 ​ ​ 55,902 Other comprehensive income: ​ ​ ​ ​ ​ ​ ​ ​ Unrealized (loss) gain on available-for-sale securities ​ (205) ​ ​ 56 ​ ​ 468 Comprehensive income $ 110,002 ​ $ 24,237 ​ $ 56,370 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ See accompanying notes to condensed financial statements. ​ ​ SCHEDULE I – CONDENSED FINANCIAL INFORMATION OF REGISTRANT MAGELLAN HEALTH, INC. (Parent Company Only) CONDENSED STATEMENTS OF CASH FLOWS FOR THE YEARS ENDED DECEMBER 31, (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Cash flows from operating activities: ​ ​ ​ ​ ​ ​ ​ ​ Net cash used in operating activities $ (21,778) ​ $ (54,394) ​ $ (51,423) Cash flows from investing activities: ​ ​ ​ ​ ​ ​ ​ ​ Dividends (capital contributions to)/received from subsidiaries, net (836,396) ​ 205,466 ​ 80,511 Net cash (used in) provided by investing activities (836,396) ​ 205,466 ​ 80,511 Cash flows from financing activities: ​ ​ ​ ​ ​ ​ ​ ​ Proceeds from issuance of debt 841,736 ​ — ​ — Proceeds from exercise of stock options ​ 44,355 ​ ​ 23,064 ​ ​ 32,715 Payments to acquire treasury stock (21,765) ​ (63,040) ​ (3,725) Payments on debt ​ (4,375) ​ ​ (110,000) ​ ​ (58,567) Other (1,777) ​ (1,096) ​ 489 Net cash provided by (used in) financing activities 858,174 ​ (151,072) ​ (29,088) Net increase (decrease) in cash and cash equivalents — ​ — ​ — Cash and cash equivalents at beginning of period 2 ​ 2 ​ 2 Cash and cash equivalents at end of period $ 2 ​ $ 2 ​ $ 2 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ See accompanying notes to condensed financial statements. ​ SCHEDULE I – CONDENSED FINANCIAL INFORMATION OF REGISTRANT MAGELLAN HEALTH, INC. (Parent Company Only) NOTES TO CONDENSED FINANCIAL STATEMENTS December 31, 2019 1. Basis of Presentation Magellan’s parent company condensed financial statements should be read in conjunction with its consolidated financial statements, and the accompanying notes thereto, included in this Form 10-K. 3. Subsidiary Transactions Magellan’s investment in subsidiaries is stated at cost plus equity in undistributed earnings of subsidiaries. When Magellan receives dividends from its subsidiaries, such amounts are recorded as a reduction to the investments in the respective subsidiaries. Magellan made capital contributions to certain subsidiaries primarily to comply with minimum net worth requirements and to fund acquisitions. During 2017, 2018 and 2019, Magellan received cash dividends from its subsidiaries of $34.7 million, $68.0 million and $61.7 million, respectively. 4. Leases Certain of our leases are obligations of the parent company. At December 31, 2019, these leases had an aggregate right-of-use asset of $23.5 million, a lease liability balance of $28.4 million, operating lease expense of $8.5 million and future lease payments as follows: 2020, $3.8 million; 2021, $4.9 million; 2022, $5.2 million; 2023, $5.3 million; 2024, $5.1 million; and thereafter $4.1 million. All other information regarding leases is contained Note 2—“Summary of Significant Accounting Policies” to the consolidated financial statements for discussion of Magellan’s leases set forth elsewhere herein. 5. Long Term Debt See Note 5—“Long Term Debt and Capital Lease Obligations” to the consolidated financial statements for discussion of Magellan’s long-term debt obligations set forth elsewhere herein. As of December 31, 2019, the contractual maturities of the term loan under the 2019 Credit Agreement were as follows: 2020—$0.0 million; 2021—$5.0 million; 2022—$17.5 million; and 2023—$258.1 million. In 2024, Magellan’s 4.400% Senior Notes will mature.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Summary of Significant Accounting Policies
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-02, “Leases” (“ASU 2016-02”). This ASU amends the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets. The FASB also issued various ASUs which subsequently amended ASU 2016-02. These amendments and ASU 2016-02, collectively known as Accounting Standard Codification 842 (“ASC 842”), are effective for annual and interim reporting periods of public entities beginning after December 15, 2018. The Company adopted ASC 842 on a modified retrospective ​ ​ The cumulative effect of the change to our consolidated January 1, 2019 balance sheet for the adoption of ASC 842 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at December 31, 2018 Adjustments Due to ASC 842 Balance at January 1, 2019 Assets ​ ​ ​ ​ ​ ​ ​ ​ Deferred income taxes $ 3,411 ​ $ 51 ​ $ 3,462 Other long-term assets ​ 24,530 ​ ​ 59,820 ​ ​ 84,350 Total Assets ​ 2,979,056 ​ ​ 59,871 ​ ​ 3,038,927 ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities and Stockholders' Equity ​ ​ ​ ​ ​ ​ ​ ​ Accrued liabilities ​ 231,356 ​ ​ 13,018 ​ ​ 244,374 Total Current Liabilities ​ 898,893 ​ ​ 13,018 ​ ​ 911,911 Deferred credits and other long-term liabilities ​ 36,483 ​ ​ 46,999 ​ ​ 83,482 Total Liabilities ​ 1,693,753 ​ ​ 60,017 ​ ​ 1,753,770 Retained earnings ​ 1,419,449 ​ ​ (144) ​ ​ 1,419,305 Total Stockholders' Equity ​ 1,285,303 ​ ​ (144) ​ ​ 1,285,159 Total Liabilities and Stockholders' Equity ​ 2,979,056 ​ ​ 59,871 ​ ​ 3,038,927 ​ In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (“ASU 2016-13”). This ASU amends the accounting on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities. This guidance is effective for annual and interim periods of public entities beginning after December 15, 2019, with early adoption permitted for fiscal years beginning after December 31, 2018. The Company does not anticipate the adoption of this ASU will have a material impact on the Company’s consolidated results of operation, financial position and cash flows. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment” (“ASU 2017-04”). The amendments in this ASU eliminate the requirement to calculate the implied fair value of goodwill to measure a goodwill impairment charge. This guidance is effective for annual and interim periods of public entities beginning after December 15, 2019, with early adoption permitted. The Company does not anticipate the adoption of this ASU will have a material impact on the Company’s consolidated results of operation, financial position and cash flows. In August 2018, the FASB issued ASU No. 2018-15, “Intangibles-Goodwill and Other–Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract” (“ASU 2018-15”). This ASU aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This guidance is effective for annual and interim periods of public entities beginning after December 15, 2019, with early adoption permitted. The Company does not anticipate the adoption of this ASU will have a material impact on the Company’s consolidated results of operation, financial position and cash flows.
Use of Estimates	The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant estimates of the Company can include, among other things, valuation of goodwill and intangible assets, medical claims payable, other medical liabilities, stock compensation assumptions, tax contingencies and legal liabilities. In addition, the Company also makes estimates in relation to revenue recognition under Accounting Standard Codification 606 (“ASC 606”) which are explained in more detail in “ Revenue Recognition ​
Revenue Recognition	Revenue Recognition ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2018 ​ Healthcare Pharmacy Management Elimination Total Major Service Lines ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Behavioral & Specialty Health ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP $ 1,511,532 ​ $ — ​ $ (263) ​ $ 1,511,269 EAP risk-based ​ 349,751 ​ ​ — ​ ​ — ​ ​ 349,751 ASO ​ 247,953 ​ ​ 34,130 ​ ​ (344) ​ ​ 281,739 Magellan Complete Care ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP ​ 2,473,570 ​ ​ — ​ ​ — ​ ​ 2,473,570 ASO ​ 55,816 ​ ​ — ​ ​ — ​ ​ 55,816 PBM, including dispensing ​ — ​ ​ 2,183,151 ​ ​ (189,708) ​ ​ 1,993,443 Medicare Part D ​ — ​ ​ 442,266 ​ ​ — ​ ​ 442,266 PBA ​ — ​ ​ 132,112 ​ ​ — ​ ​ 132,112 Formulary management ​ — ​ ​ 70,900 ​ ​ — ​ ​ 70,900 Other ​ — ​ ​ 3,285 ​ ​ — ​ ​ 3,285 Total net revenue $ 4,638,622 ​ $ 2,865,844 ​ $ (190,315) ​ $ 7,314,151 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Type of Customer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Government $ 3,432,901 ​ $ 946,606 ​ $ — ​ $ 4,379,507 Non-government ​ 1,205,721 ​ ​ 1,919,238 ​ ​ (190,315) ​ ​ 2,934,644 Total net revenue $ 4,638,622 ​ $ 2,865,844 ​ $ (190,315) ​ $ 7,314,151 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Timing of Revenue Recognition ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Transferred at a point in time $ — ​ $ 2,625,417 ​ $ (189,708) ​ $ 2,435,709 Transferred over time ​ 4,638,622 ​ ​ 240,427 ​ ​ (607) ​ ​ 4,878,442 Total net revenue $ 4,638,622 ​ $ 2,865,844 ​ $ (190,315) ​ $ 7,314,151 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2019 ​ Healthcare Pharmacy Management Elimination Total Major Service Lines ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Behavioral & Specialty Health ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP $ 1,504,472 ​ $ — ​ $ (290) ​ $ 1,504,182 EAP risk-based ​ 339,377 ​ ​ — ​ ​ — ​ ​ 339,377 ASO ​ 237,186 ​ ​ 40,348 ​ ​ (302) ​ ​ 277,232 Magellan Complete Care ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP ​ 2,695,132 ​ ​ — ​ ​ — ​ ​ 2,695,132 ASO ​ 62,379 ​ ​ — ​ ​ — ​ ​ 62,379 PBM, including dispensing ​ — ​ ​ 1,949,225 ​ ​ (180,799) ​ ​ 1,768,426 Medicare Part D ​ — ​ ​ 287,604 ​ ​ — ​ ​ 287,604 PBA ​ — ​ ​ 137,885 ​ ​ — ​ ​ 137,885 Formulary management ​ — ​ ​ 84,567 ​ ​ — ​ ​ 84,567 Other ​ — ​ ​ 2,639 ​ ​ — ​ ​ 2,639 Total net revenue $ 4,838,546 ​ $ 2,502,268 ​ $ (181,391) ​ $ 7,159,423 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Type of Customer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Government $ 3,674,152 ​ $ 831,673 ​ $ — ​ $ 4,505,825 Non-government ​ 1,164,394 ​ ​ 1,670,595 ​ ​ (181,391) ​ ​ 2,653,598 Total net revenue $ 4,838,546 ​ $ 2,502,268 ​ $ (181,391) ​ $ 7,159,423 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Timing of Revenue Recognition ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Transferred at a point in time $ — ​ $ 2,236,829 ​ $ (180,799) ​ $ 2,056,030 Transferred over time ​ 4,838,546 ​ ​ 265,439 ​ ​ (592) ​ ​ 5,103,393 Total net revenue $ 4,838,546 ​ $ 2,502,268 ​ $ (181,391) ​ $ 7,159,423 ​ Per Member Per Month (“PMPM”) Revenue. Under certain government contracts, our risk scores are compared with the overall average risk scores for the relevant state and market pool. Generally, if our risk score is below the average risk score we are required to make a risk adjustment payment into the risk pool, and if our risk score is above the average risk score we will receive a risk adjustment payment from the risk pool. Risk adjustments can have a positive or negative retroactive impact to rates. ​ Pharmacy Benefit Management Revenue. The Company’s customers for PBM business, including pharmaceutical dispensing operations, are generally comprised of MCOs, employer groups and health plans. PBM relationships generally have an expected term of one year or longer. A master services arrangement (“MSA”) is executed by the Company and the customer, which outlines the terms and conditions of the PBM services to be provided. When a member in the customer’s organization submits a prescription, a claim is created which is presented for approval. The acceptance of each individual claim creates enforceable rights and obligations for each party and represents a separate contract. For each individual claim, the performance obligations are limited to the processing and adjudication of the claim, or dispensing of the products purchased. Generally, the transaction price for PBM services is explicitly listed in each contract and does not represent variable consideration. The Company recognizes PBM revenue, which consists of a negotiated prescription price (ingredient cost plus dispensing fee), co-payments and any associated administrative fees, when claims are adjudicated or the drugs are shipped. The Company recognizes PBM revenue on a gross basis (i.e. including drug costs and co-payments) as it is acting as the principal in the arrangement, controls the underlying service, and is contractually obligated to its clients and network pharmacies, which is a primary indicator of gross reporting. In addition, the Company is solely responsible for the claims adjudication process, negotiating the prescription price for the pharmacy, collecting payments from the client for drugs dispensed by the pharmacy, and managing the total prescription drug relationship with the client’s members. If the Company enters into a contract where it is only an administrator, and does not assume any of the risks previously noted, revenue will be recognized on a net basis. For dispensing, at the time of shipment, the earnings process is complete; the obligation of the Company’s customer to pay for the specialty pharmaceutical drugs is fixed, and, due to the nature of the product, the member may neither return the specialty pharmaceutical drugs nor receive a refund. Medicare Part D. st Pharmacy Benefit Administration Revenue. Formulary Management Revenue. The Company administers formulary management programs for certain clients through which the Company coordinates the achievement, calculation and collection of rebates and administrative fees from pharmaceutical manufacturers on behalf of clients. Formulary management contracts generally have a term of one year or longer. All formulary management contracts have a single performance obligation that constitutes a series for the provision of rebate services for a drug, with utilization measured and settled on a quarterly basis, for the duration of the arrangement. The Company retains its administrative fee and/or a percentage of rebates that is included in its contract with the client from collecting the rebate from the manufacturer. While the administrative fee and/or the percentage of rebates retained is fixed, there is an unknown quantity of pharmaceutical purchases (utilization) during each quarter; therefore the transaction price itself is variable. The Company uses the expected value methodology to estimate the total rebates earned each quarter based on estimated volumes of pharmaceutical purchases by the Company’s clients during the quarter, as well as historical and/or anticipated retained rebate percentages. The Company does not record as rebate revenue any rebates that are passed through to its clients. ​ In relation to the Company’s PBM business, the Company administers rebate programs through which it receives rebates from pharmaceutical manufacturers that are shared with its customers. The Company recognizes rebates when the Company is entitled to them and when the amounts of the rebates are determinable. The amount recorded for rebates earned by the Company from the pharmaceutical manufacturers is recorded as a reduction of cost of goods sold. Government EAP Risk-Based Revenue. The Company has certain contracts with federal customers for the provision of various managed care services, which are classified as EAP risk-based business. These contracts are generally multi-year arrangements. The Company’s federal contracts are reimbursed on either a fixed fee basis or a cost reimbursement basis. The performance obligation on a fixed fee contract is to stand ready to provide the staffing required for the contracted period. For fixed fee contracts, the Company believes the invoiced amount corresponds directly with the value to the customer of the Company’s performance completed to date; therefore, the Company is utilizing the “right to invoice” practical expedient, with revenue recognition in the amount for which the Company has the right to invoice. The performance obligation on a cost reimbursement contract is to stand ready to provide the activity or services purchased by the customer, such as the operation of a counseling services group or call center. The performance obligation represents a series for the duration of the arrangement. The reimbursement rate is fixed per the contract; however, the level of activity (e.g., number of hours, number of counselors or number of units) is variable. A majority of the Company’s cost reimbursement transaction price relates specifically to its efforts to transfer the service for a distinct increment of the series (e.g. day or month) and is recognized as revenue when the portion of the series for which it relates has been provided (i.e. as the Company provides hours, counselors or units of service). In accordance with ASC 606-10-50-13, the Company is required to include disclosure on its remaining performance obligations as of the end of the current reporting period. Due to the nature of the contracts in the Company’s PBM and Part D business, these reporting requirements are not applicable. The majority of the Company’s remaining contracts meet certain exemptions as defined in ASC 606-10-50-14 through 606-10-50-14A, including (i) performance obligation is part of a contract that has an original expected duration of one year or less; (ii) the right to invoice practical expedient; and (iii) variable consideration related to unsatisfied performance obligations that is allocated entirely to a wholly unsatisfied promise to transfer a distinct service that forms part of a single performance obligation, and the terms of that variable consideration relate specifically to our efforts to transfer the distinct service, or to a specific outcome from transferring the distinct service. For the Company’s contracts that pertain to these exemptions: (i) the remaining performance obligations primarily relate to the provision of managed healthcare services to the customers’ membership; (ii) the estimated remaining duration of these performance obligations ranges from the remainder of the current calendar year to three years; and (iii) variable consideration for these contracts primarily includes net per member per month fees associated with unspecified membership that fluctuates throughout the contract. Accounts Receivable, Contract Assets and Contract Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ ​ 2018 ​ 2019 ​ $ Change ​ % Change ​ Accounts receivable $ 786,395 ​ $ 915,656 ​ $ 129,261 ​ ​ 16.4% ​ Contract assets ​ 4,647 ​ ​ 2,231 ​ ​ (2,416) ​ ​ (52.0%) ​ Contract liabilities - current ​ 16,853 ​ ​ 6,728 ​ ​ (10,125) ​ ​ (60.1%) ​ Contract liabilities - long-term ​ 13,441 ​ ​ 11,099 ​ ​ (2,342) ​ ​ (17.4%) ​ ​ 2020 2021 2022 2023 Significant Customers Customers exceeding ten percent of the consolidated Company’s net revenues The Company has contracts with the Commonwealth of Virginia (the “Virginia Contracts”). The Company began providing Medicaid managed long-term services and supports to enrollees in the Commonwealth Coordinated Care Plus (“CCC Plus”) program on August 1, 2017. The CCC Plus contract expires annually on December 31, and automatically renews annually on January 1 for a period of five The Company had a contract with the State of New York (the “New York Contract”) to provide integrated managed care services to Medicaid and Medicare enrollees in the State of New York. The Company’s New York Contract terminated on December 31, 2016; however, the Company, along with other participating managed care plans in the state, continues to provide services while a new contract is being finalized. The Company began recognizing revenue in relation to the New York Contract on January 1, 2014 as a result of the acquisition of AlphaCare Holdings, Inc. The Company’s revenues under the New York Contracts increased starting on November 1, 2017 as a result of the acquisition of SWH Holdings, Inc. The New York Contracts generated net revenues of $265.2 million, $691.6 million and $836.4 million for the years ended December 31, 2017, 2018 and 2019, respectively. The Company has contracts with the Commonwealth of Massachusetts and CMS (the “Massachusetts Contracts”) to provide integrated managed care services to Medicaid and Medicare enrollees in the Commonwealth of Massachusetts. Medicaid services are provided under a Senior Care Options contract (“SCO Contract”) which began on January 1, 2016 and extends through December 31, 2021, with the potential for up to five additional one year extensions. The Commonwealth of Massachusetts may terminate the contract with cause without prior notice and upon 180 days ’ notice without cause. Medicare services are provided under a one-year contract with CMS. The CMS contract currently extends through December 31, 2019. The Company began recognizing revenue in relation to the Massachusetts Contracts on November 1, 2017 as a result of the acquisition of SWH Holdings, Inc. The Massachusetts Contracts generated net revenues of $109.1 million, $682.1 million and $718.9 million for the years ended December 31, 2017, 2018 and 2019, respectively. ​ Customers exceeding ten percent of segment net revenues In addition to the Massachusetts Contracts, New York Contract and Virginia Contracts previously discussed, the following customers generated in excess of ten percent of net revenues for the respective segment for the respective segment for the years ended December 31, 2017, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Term Date 2017 2018 2019 Healthcare ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Customer A ​ December 31, 2023 ​ $ 605,917 ​ $ 618,227 ​ $ 211,106 * ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pharmacy Management ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Customer B ​ March 31, 2021 ​ ​ 346,405 ​ ​ 344,479 ​ ​ 335,682 ​ * Revenue amount did not exceed 10 percent of net revenues for the respective segment for the year presented. Amount is shown for comparative purposes only. Concentration of Business The Company also has a significant concentration of business with various counties in the State of Pennsylvania (the “Pennsylvania Counties”) which are part of the Pennsylvania Medicaid program, with members under its contract with CMS and with various agencies and departments of the United States federal government. Net revenues from the Pennsylvania Counties in the aggregate totaled $490.0 million, $544.6 million and $537.8 million for the years ended December 31, 2017, 2018 and 2019, respectively. Net revenues from members in relation to its contract with CMS in aggregate totaled $511.0 million, $442.3 million and $287.6 million for the years ended December 31, 2017, 2018 and 2019, respectively. Net revenues from contracts with various agencies and departments of the United States federal government in aggregate totaled $341.5 million, $308.7 million, and $299.2 million for the years ended December 31, 2017, 2018 and 2019, respectively. The Company’s contracts with customers typically have stated terms of one one
Income Taxes	Income Taxes The Company files a consolidated federal income tax return with its eighty-percent or more controlled subsidiaries. The Company previously filed separate consolidated federal income tax returns for AlphaCare of New York, Inc. (“AlphaCare”) and its parent, AlphaCare Holdings, Inc. (“AlphaCare Holdings”). During 2017, AlphaCare and AlphaCare Holdings became members of the Magellan federal consolidated group. The Company and its subsidiaries also file income tax returns in various state and local jurisdictions. The Company estimates income taxes for each of the jurisdictions in which it operates. This process involves determining both permanent and temporary differences resulting from differing treatment for tax and book purposes. Deferred tax assets and/or liabilities are determined by multiplying the temporary differences between the financial reporting and tax reporting bases for assets and liabilities by the enacted tax rates expected to be in effect when such differences are recovered or settled. The Company then assesses the likelihood that the deferred tax assets will be recovered from the reversal of temporary differences, the implementation of feasible and prudent tax planning strategies, and future taxable income. To the extent the Company cannot conclude that recovery is more likely than not, it establishes a valuation allowance. The effect of a change in tax rates on deferred taxes is recognized in income in the period that includes the enactment date. Reversals of both valuation allowances and unrecognized tax benefits are recorded in the period they occur, typically as reductions to income tax expense. The Company recognizes interim period income taxes by estimating an annual effective tax rate and applying it to year-to-date results. The estimated annual effective tax rate is periodically updated throughout the year based on actual results to date and an updated projection of full year income. Although the effective tax rate approach is generally used for interim periods, taxes on significant, unusual and infrequent items are recognized at the statutory tax rate entirely in the period the amounts are realized.
Health Care Reform	Health Care Reform The Patient Protection and the Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010 (collectively, the “Health Reform Law”), imposes a mandatory annual fee on health insurers for each calendar year beginning on or after January 1, 2014. The Company has obtained rate adjustments from customers which the Company expects will cover the direct costs of these fees and the impact from non-deductibility of such fees for federal and state income tax purposes. To the extent the Company has such a customer that does not renew, there may be some impact due to taxes paid where the timing and amount of recoupment of these additional costs is uncertain. In the event the Company is unable to obtain rate adjustments to cover the financial impact of the annual fee, the fee may have a material impact on the Company. The Consolidated Appropriations Act of 2016 imposed a one-year moratorium on the Patient Protection and Affordable Care Act health insurer fee (“HIF”) fee, suspending its application for 2017. The HIF fee went back into effect for 2018, however, on January 23, 2018 the United States Congress passed the Continuing Resolution which imposed another one-year moratorium on the HIF fee, suspending its application for 2019. For 2018, the HIF fees were $29.9 million, which have been paid and are included in direct service costs and other operating expenses in the consolidated statements of income.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents are short-term, highly liquid interest-bearing investments with maturity dates of three months or less when purchased, consisting primarily of money market instruments. Book overdrafts are reflected within accounts payable on the balance sheets. There were no book overdrafts at December 31, 2018. At December 31, 2019, the Company had $0.5 million in book overdrafts. At December 31, 2019, the Company’s excess capital and undistributed earnings for the Company’s regulated subsidiaries of $134.8 million are included in cash and cash equivalents.
Restricted Assets	Restricted Assets The Company has certain assets which are considered restricted for: (i) the payment of claims under the terms of certain managed care contracts; (ii) regulatory purposes related to the payment of claims in certain jurisdictions; and (iii) the maintenance of minimum required tangible net equity levels for certain of the Company’s subsidiaries. Significant restricted assets of the Company as of December 31, 2018 and 2019 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 2019 Restricted cash and cash equivalents ​ $ 160,967 ​ $ 146,455 ​ Restricted short-term investments ​ 363,840 ​ 318,464 ​ Restricted deposits (included in other current assets) ​ 43,401 ​ 38,602 ​ Restricted long-term investments ​ 2,854 ​ 10,111 ​ Total ​ $ 571,062 ​ $ 513,632 ​ The Company’s equity in restricted net assets of consolidated subsidiaries represented approximately 28.1% of the Company’s consolidated stockholders’ equity as of December 31, 2019 and consisted of net assets of the Company which were restricted as to transfer to Magellan in the form of cash dividends, loans or advances under regulatory restrictions.
Fair Value Measurements	Fair Value Measurements The Company has certain assets and liabilities that are required to be measured at fair value on a recurring basis. These assets and liabilities are to be measured using inputs from the three levels of the fair value hierarchy, which are as follows: Level 1—Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. Level 2—Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.), and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). Level 3—Unobservable inputs that reflect the Company’s assumptions about the assumptions that market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available, including the Company’s data. In accordance with the fair value hierarchy described above, the following table shows the fair value of the Company’s financial assets and liabilities that are required to be measured at fair value as of December 31, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 ​ ​ Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents (1) $ — $ 263,462 $ — $ 263,462 ​ Investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Government and agency securities ​ 67,815 ​ — ​ — ​ 67,815 ​ Obligations of government-sponsored enterprises (2) ​ — ​ 5,229 ​ — ​ 5,229 ​ Corporate debt securities ​ — ​ 292,049 ​ — ​ 292,049 ​ Certificates of deposit ​ — ​ 20,650 ​ — ​ 20,650 ​ Total assets held at fair value ​ $ 67,815 ​ $ 581,390 ​ $ — ​ $ 649,205 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ $ — ​ $ — ​ $ 10,124 ​ $ 10,124 ​ Total liabilities held at fair value ​ $ — ​ $ — ​ $ 10,124 ​ $ 10,124 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents (3) $ — $ 313,509 $ — $ 313,509 ​ Investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Government and agency securities ​ 104,159 ​ — ​ — ​ 104,159 ​ Corporate debt securities ​ — ​ 239,693 ​ — ​ 239,693 ​ Certificates of deposit ​ — ​ 1,305 ​ — ​ 1,305 ​ Total assets held at fair value ​ $ 104,159 ​ $ 554,507 ​ $ — ​ $ 658,666 ​ (1) Excludes $8.8 million of cash held in bank accounts by the Company. (2) Includes investments in notes issued by the Federal Home Loan Bank, Federal Farm Credit Banks and Federal National Mortgage Association. (3) Excludes $11.7 million of cash held in bank accounts by the Company. For the years ended December 31, 2018 2019 Company not The carrying values of financial instruments, including accounts receivable and accounts payable, approximate their fair values due to their short-term maturities. The fair value of the Notes (as defined below) of $403.4 million as of December 31, 2019 was determined based on quoted market prices and would be classified within Level 1 of the fair value hierarchy. The estimated fair value of the Company’s term loan of $280.6 million as of December 31, 2019 was based on current interest rates for similar types of borrowings and is in Level 2 of the fair value hierarchy. The estimated fair values may not represent actual values of the financial instruments that could be realized as of the balance sheet date or that will be realized in the future. All of the Company’s investments are classified as “available-for-sale” and are carried at fair value. As of the balance sheet date, the fair value of contingent consideration is determined based on probabilities of payment, projected payment dates, discount rates, projected operating income, member engagement and new contract execution. The Company used a probability weighted discounted cash flow method to arrive at the fair value of the contingent consideration. As the fair value measurement for the contingent consideration is based on inputs not observed in the market, these measurements are classified as Level 3 measurements as defined by fair value measurement guidance. The unobservable inputs used in the fair value measurement include the discount rate, probabilities of payment and projected payment dates. As of December 31, 2018, the Company estimated undiscounted future contingent payments of $10.6 million. As of December 31, 2018, the fair value of the short-term and long-term contingent consideration was $8.0 million and $2.1 million, respectively, and is included in short-term contingent consideration and long-term contingent consideration, respectively, in the consolidated balance sheets. As of December 31, 2019, the Company had no estimated future contingent payments. The change in the fair value of the contingent consideration was $0.7 million, $1.3 million and $(2.1) million for the years ended December 31, 2017, 2018 and 2019, respectively, which were recorded as direct service costs and other operating expenses in the consolidated statements of income. The decreases during 2019 were mainly a result of changes in the estimated undiscounted liability. The following table summarizes the Company’s liability for contingent consideration (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ 2018 2019 Balance as of beginning of period ​ $ 8,817 ​ $ 10,124 ​ Changes in fair value ​ 1,307 ​ (2,124) ​ Payments ​ ​ — ​ ​ (8,000) ​ Balance as of end of period ​ $ 10,124 ​ $ — ​ ​
Investments	Investments All of the Company’s investments are classified as “available-for-sale” and are carried at fair value. Securities which have been classified as Level 1 are measured using quoted market prices in active markets for identical assets or liabilities while those which have been classified as Level 2 are measured using quoted prices for identical assets and liabilities in markets that are not active. The Company’s policy is to classify all investments with contractual maturities within one year as current. Investment income is recognized when earned and reported net of investment expenses. Net unrealized holding gains or losses are excluded from earnings and are reported, net of tax, as “accumulated other comprehensive income (loss)” in the accompanying consolidated balance sheets and consolidated statements of comprehensive income until realized, unless the losses are deemed to be other-than-temporary. Realized gains or losses, including any provision for other-than-temporary declines in value, are included in the consolidated statements of income. If a debt security is in an unrealized loss position and the Company has the intent to sell the debt security, or it is more likely than not that the Company will have to sell the debt security before recovery of its amortized cost basis, the decline in value is deemed to be other-than-temporary and is recorded to other-than-temporary impairment losses recognized in income in the consolidated statements of income. For impaired debt securities that the Company does not intend to sell or it is more likely than not that the Company will not have to sell such securities, but the Company expects that it will not fully recover the amortized cost basis, the credit component of the other-than-temporary impairment is recognized in other-than-temporary impairment losses recognized in income in the consolidated statements of income and the non-credit component of the other-than-temporary impairment is recognized in other comprehensive income. The credit component of an other-than-temporary impairment is determined by comparing the net present value of projected future cash flows with the amortized cost basis of the debt security. The net present value is calculated by discounting the best estimate of projected future cash flows at the effective interest rate implicit in the debt security at the date of acquisition. Cash flow estimates are driven by assumptions regarding probability of default, including changes in credit ratings, and estimates regarding timing and amount of recoveries associated with a default. Furthermore, unrealized losses entirely caused by non-credit related factors related to debt securities for which the Company expects to fully recover the amortized cost basis continue to be recognized in accumulated other comprehensive income. As of December 31, 2018 and 2019, there were no material unrealized losses that the Company believed to be other-than-temporary. No realized gains or losses were recorded for the years ended December 31, 2017, 2018, or 2019. The following is a summary of short-term and long-term investments at December 31, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Estimated ​ Cost Gains Losses Fair Value U.S. Government and agency securities $ 67,870 $ 17 $ (72) $ 67,815 ​ Obligations of government-sponsored enterprises (1) ​ 5,257 ​ — ​ (28) ​ 5,229 ​ Corporate debt securities ​ 292,392 ​ 6 ​ (349) ​ 292,049 ​ Certificates of deposit ​ 20,650 ​ — ​ — ​ 20,650 ​ Total investments at December 31, 2018 ​ $ 386,169 ​ $ 23 ​ $ (449) ​ $ 385,743 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Estimated ​ Cost Gains Losses Fair Value U.S. Government and agency securities $ 104,096 $ 75 $ (12) $ 104,159 ​ Corporate debt securities ​ 239,564 ​ 175 ​ (46) ​ 239,693 ​ Certificates of deposit ​ ​ 1,305 ​ — ​ — ​ 1,305 ​ Total investments at December 31, 2019 ​ $ 344,965 ​ $ 250 ​ $ (58) ​ $ 345,157 ​ (1) Includes investments in notes issued by the Federal Home Loan Bank, Federal National Mortgage Association and Federal Farm Credit Banks. The maturity dates of the Company’s investments as of December 31, 2019 are summarized below (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized Estimated ​ Cost Fair Value 2020 ​ $ 334,304 ​ $ 334,489 ​ 2021 ​ ​ 10,661 ​ ​ 10,668 ​ Total investments at December 31, 2019 $ 344,965 $ 345,157 ​ ​
Concentration of Credit Risk	Concentration of Credit Risk Accounts receivable subjects the Company to a concentration of credit risk with third party payors that include health insurance companies, managed healthcare organizations, healthcare providers and governmental entities. The Company maintains cash and cash equivalents balances at financial institutions which are insured by the Federal Deposit Insurance Corporation (“FDIC”). At times, balances in certain bank accounts may exceed the FDIC insured limits.
Pharmaceutical Inventory	Pharmaceutical Inventory Pharmaceutical inventory consists solely of finished goods (primarily prescription drugs) and is stated at the lower of first-in first-out, cost, or market.
Long-lived Assets	Long-lived Assets Long-lived assets, including property and equipment and intangible assets to be held and used, are currently reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. We group and evaluate these long-lived assets for impairment at the lowest level at which individual cash flows can be identified. Impairment is determined by comparing the carrying value of these long-lived assets to management’s best estimate of the future undiscounted cash flows expected to result from the use of the assets and their eventual disposition. The cash flow projections used to make this assessment are consistent with the cash flow projections that management uses internally in making key decisions. In the event an impairment exists, a loss is recognized based on the amount by which the carrying value exceeds the fair value of the asset, which is generally determined by using quoted market prices or the discounted present value of expected future cash flows. In the evaluation of indefinite-lived intangible assets for impairment, the Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of the indefinite-lived intangible asset is less than its carrying value. If the Company determines that it is not more likely than not for the indefinite-lived intangible asset’s fair value to be less than its carrying value, a calculation of the fair value is not performed. If the Company determines that it is more likely than not that the indefinite-lived intangible asset’s fair value is less than its carrying value, a calculation is performed and compared to the carrying value of the asset. If the carrying amount of the indefinite-lived intangible asset exceeds its fair value, an impairment loss is recognized in an amount equal to that excess. The Company measures the fair value of its indefinite-lived intangible assets using the “relief from royalty” method. Significant estimates in this approach include projected revenues and royalty and discount rates for each trade name evaluated.
Property and Equipment	Property and Equipment Property and equipment is stated at cost, except for assets that have been impaired, for which the carrying amount has been reduced to estimated fair value. Expenditures for renewals and improvements are capitalized to the property accounts. Replacements and maintenance and repairs that do not improve or extend the life of the respective assets are expensed as incurred. The Company capitalizes costs incurred to develop internal-use software during the application development stage. Capitalization of software development costs occurs after the preliminary project stage is complete, management authorizes the project, and it is probable that the project will be completed and the software will be used for the function intended. Amortization of capital lease assets is included in depreciation expense and is included in accumulated depreciation as reflected in the table below. Depreciation is provided on a straight-line basis over the estimated useful lives of the assets, which is generally two three three Property and equipment, net, consisted of the following at December 31, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 2019 Building improvements ​ $ 18,954 ​ $ 18,546 ​ Equipment ​ 201,343 ​ 200,238 ​ Finance leases - property ​ 26,945 ​ 26,945 ​ Finance leases - equipment ​ 24,932 ​ 29,088 ​ Capitalized internal-use software ​ 527,129 ​ 570,989 ​ ​ ​ 799,303 ​ 845,806 ​ Accumulated depreciation ​ (648,555) ​ (707,384) ​ Property and equipment, net ​ $ 150,748 ​ $ 138,422 ​ ​
Goodwill	Goodwill The Company is required to test its goodwill for impairment on at least an annual basis. The Company has selected October 1 as the date of its annual impairment test. The goodwill impairment test is a two-step process that requires management to make judgments in determining what assumptions to use in the calculation. The first step of the process consists of estimating the fair value of each reporting unit with goodwill based on various valuation techniques, with the primary technique being a discounted cash flow analysis, which requires the input of various assumptions with respect to revenues, operating margins, growth rates and discount rates. The estimated fair value for each reporting unit is compared to the carrying value of the reporting unit, which includes goodwill. If the estimated fair value is less than the carrying value, a second step is performed to compute the amount of the impairment by determining an “implied fair value” of goodwill. The determination of a reporting unit’s “implied fair value” of goodwill requires the Company to allocate the estimated fair value of the reporting unit to the assets and liabilities of the reporting unit. Any unallocated fair value represents the “implied fair value” of goodwill, which is compared to its corresponding carrying value. December 31, 2019 Behavioral & Specialty Health, MCC Pharmacy Management The fair values of the Behavioral & Specialty Health (a component of the Healthcare segment), MCC (a component of the Healthcare segment) and Pharmacy Management reporting units were determined using a discounted cash flow method. This method involves estimating the present value of estimated future cash flows utilizing a risk adjusted discount rate. Key assumptions for this method include cash flow projections, terminal growth rates and discount rates. The 2018 annual goodwill impairment testing as of October 1, 2018, determined that the fair value of the MCC reporting unit had declined, largely due to continued economic challenges in certain markets, and was in excess of its carrying value by a margin of approximately 5%, designating it as a reporting unit that was at-risk for impairment. After performing the 2019 annual goodwill impairment test, improvements were noted in the actual and expected results for such MCC markets which increased the estimated fair value of the MCC reporting unit. As of October 1, 2019, the excess of its fair value over the carrying value increased to an extent that it is no longer considered at-risk. While no units were determined to be impaired at this time, reporting unit goodwill is at risk of future impairment in the event of significant unfavorable changes in the Company’s forecasted future results and cash flows. In addition, market factors utilized in the impairment analysis, including long-term growth rates or discount rates, could negatively impact the fair value of our reporting units. For testing purposes, management's best estimates of the expected future results are the primary driver in determining the fair value. Fair value determinations require considerable judgment and are sensitive to changes in underlying assumptions and factors. As a result, there can be no assurance that the estimates and assumptions made for purposes of the annual goodwill test will prove to be an accurate prediction of the future. Examples of events or circumstances that could reasonably be expected to negatively affect the underlying key assumptions and ultimately impact the estimated fair value of our reporting units may include such items as: (i) a decrease in expected future cash flows, specifically, a decrease in membership or rates or customer attrition and increase in costs that could significantly impact our immediate and long-range results, unfavorable working capital changes and an inability to successfully achieve our cost savings targets, (ii) adverse changes in macroeconomic conditions or an economic recovery that significantly differs from our assumptions in timing and/or degree (such as a recession); and (iii) volatility in the equity and debt markets or other country specific factors which could result in a higher weighted average cost of capital. Based on known facts and circumstances, we evaluate and consider recent events and uncertain items, as well as related potential implications, as part of our annual assessment and incorporate into the analyses as appropriate. These facts and circumstances are subject to change and may impact future analyses. While historical performance and current expectations have resulted in fair values of our reporting units and indefinite-lived intangible assets in excess of carrying values, if our assumptions are not realized, it is possible that an impairment charge may need to be recorded in the future. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 ​ 2019 ​ Behavioral & Specialty Health ​ $ 410,869 ​ $ 410,869 ​ Magellan Complete Care ​ 211,735 ​ 211,735 ​ Pharmacy Management ​ 395,552 ​ 395,552 ​ Total ​ $ 1,018,156 ​ $ 1,018,156 ​ ​ ​ The changes in the carrying amount of goodwill for the years ended December 31, 2018 and 2019 are reflected in the table below (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 ​ 2019 ​ Balance as of beginning of period ​ $ 1,006,288 ​ $ 1,018,156 ​ Other acquisitions and measurement period adjustments ​ 11,868 ​ — ​ Balance as of end of period ​ $ 1,018,156 ​ $ 1,018,156 ​ ​
Intangible Assets	Intangible Assets The Company reviews other intangible assets for impairment when events or changes in circumstances occur which may potentially impact the estimated useful life of the intangible assets. The following is a summary of intangible assets at December 31, 2018 and 2019, and the estimated useful lives for such assets (in thousands, except useful lives): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 ​ ​ ​ ​ ​ ​ ​ ​ Weighted Avg ​ Gross ​ ​ ​ ​ Net ​ ​ Original ​ Remaining ​ Carrying ​ Accumulated ​ Carrying Asset Useful Life ​ Useful Life ​ Amount Amortization Amount Customer agreements and lists 2.5 ​ to 18 ​ years ​ 4.5 years ​ $ 441,346 $ (262,729) $ 178,617 ​ Provider networks and other 1 ​ to 16 ​ years ​ 2.3 years ​ 44,635 ​ (21,789) ​ 22,846 ​ Trade names and licenses ​ indefinite ​ indefinite ​ ​ 30,420 ​ ​ — ​ ​ 30,420 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 516,401 ​ $ (284,518) ​ $ 231,883 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ ​ ​ ​ ​ ​ ​ Weighted Avg ​ Gross ​ ​ ​ ​ Net ​ ​ Original ​ Remaining ​ Carrying ​ Accumulated ​ Carrying Asset Useful Life ​ Useful Life ​ Amount Amortization Amount Customer agreements and lists 2.5 ​ to 18 ​ years ​ 3.4 years ​ $ 441,346 $ (309,296) $ 132,050 ​ Provider networks and other 1 ​ to 16 ​ years ​ 1.6 years ​ 29,752 ​ (24,878) ​ 4,874 ​ Trade names and licenses ​ indefinite ​ indefinite ​ ​ 30,420 ​ ​ — ​ ​ 30,420 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 501,518 ​ $ (334,174) ​ $ 167,344 ​ ​ Amortization expense was $39.2 million, $51.8 million and $57.0 million for the years ended December 31, 2017, 2018 and 2019, respectively. The Company estimates amortization expense will be $56.2 million, $35.5 million, $23.8 million, $17.1 million and $4.0 million for the years ending December 31, 2020, 2021, 2022, 2023 and 2024, respectively.
Cost of Care, Medical Claims Payable and Other Medical Liabilities	Cost of Care, Medical Claims Payable and Other Medical Liabilities Cost of care is recognized in the period in which members receive managed healthcare services. In addition to actual benefits paid, cost of care in a period also includes the impact of accruals for estimates of medical claims payable. Medical claims payable represents the liability for healthcare claims reported but not yet paid and claims incurred but not yet reported (“IBNR”) related to the Company’s managed healthcare businesses. Such liabilities are determined by employing actuarial methods that are commonly used by health insurance actuaries and that meet actuarial standards of practice. Cost of care for the Company’s EAP contracts, which are mainly with the United States federal government, pertain to the costs to employ licensed behavioral health counselors to deliver non-medical counseling for these contracts. The IBNR portion of medical claims payable is estimated based on past claims payment experience for member groups, enrollment data, utilization statistics, authorized healthcare services and other factors. This data is incorporated into contract-specific actuarial reserve models and is further analyzed to create “completion factors” that represent the average percentage of total incurred claims that have been paid through a given date after being incurred. Factors that affect estimated completion factors include benefit changes, enrollment changes, shifts in product mix, seasonality influences, provider reimbursement changes, changes in claims inventory levels, the speed of claims processing and changes in paid claim levels. Completion factors are applied to claims paid through the financial statement date to estimate the ultimate claim expense incurred for the current period. Actuarial estimates of claim liabilities are then determined by subtracting the actual paid claims from the estimate of the ultimate incurred claims. For the most recent incurred months (generally the most recent two months), the percentage of claims paid for claims incurred in those months is generally low. This makes the completion factor methodology less reliable for such months. Therefore, incurred claims for any month with a completion factor that is less than 70 percent are generally not projected from historical completion and payment patterns; rather they are projected by estimating claims expense based on recent monthly estimated cost incurred per member per month times membership, taking into account seasonality influences, benefit changes and healthcare trend levels, collectively considered to be “trend factors.” For new contracts, the Company estimates IBNR based on underwriting data until it has sufficient data to utilize these methodologies. Medical claims payable balances are continually monitored and reviewed. If it is determined that the Company’s assumptions in estimating such liabilities are significantly different than actual results, the Company’s results of operations and financial position could be impacted in future periods. Adjustments of prior period estimates may result in additional cost of care or a reduction of cost of care in the period an adjustment is made. Further, due to the considerable variability of healthcare costs, adjustments to claim liabilities occur each period and are sometimes significant as compared to the net income recorded in that period. Prior period development is recognized immediately upon the actuary’s judgment that a portion of the prior period liability is no longer needed or that additional liability should have been accrued. The following table presents the components of the change in medical claims payable for the years ended December 31, 2017, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Claims payable and IBNR, beginning of period ​ $ 188,618 ​ $ 326,642 ​ $ 394,140 ​ Cost of care: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current year ​ 2,421,270 ​ 3,772,112 ​ 3,962,831 ​ Prior years(3) ​ (7,500) ​ (9,700) ​ (22,300) ​ Total cost of care ​ 2,413,770 ​ 3,762,412 ​ 3,940,531 ​ Claim payments and transfers to other medical liabilities(1): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current year ​ 2,210,346 ​ 3,402,010 ​ 3,594,018 ​ Prior years ​ 161,798 ​ 292,904 ​ 332,650 ​ Total claim payments and transfers to other medical liabilities ​ 2,372,144 ​ 3,694,914 ​ 3,926,668 ​ Acquisition of SWH ​ ​ 96,398 ​ ​ — ​ ​ — ​ Claims payable and IBNR, end of period ​ 326,642 ​ 394,140 ​ 408,003 ​ Withhold (receivables) payable, end of period(2) ​ 983 ​ (593) ​ 1,530 ​ Medical claims payable, end of period ​ $ 327,625 ​ $ 393,547 ​ $ 409,533 ​ (1) For any given period, a portion of unpaid medical claims payable could be covered by risk share or reinvestment liabilities (discussed below) and may not impact the Company’s results of operations for such periods. (2) Medical claims payable is offset by customer withholds from capitation payments in situations in which the customer has the contractual requirement to pay providers for care incurred. (3) Favorable development in 2017, 2018 and 2019 was $7.5 million, $9.7 million and $22.3 million, respectively, and was mainly related to lower medical trends and faster claims completion than originally assumed. Actuarial standards of practice require that claim liabilities be adequate under moderately adverse circumstances. Adverse circumstances are situations in which the actual claims experience could be higher than the otherwise estimated value of such claims. In many situations, the claims paid amount experienced will be less than the estimate that satisfies the actuarial standards of practice. Any prior period favorable cost of care development related to a lack of moderately adverse conditions is excluded from “Cost of Care – Prior Years” adjustments, as a similar provision for moderately adverse conditions is established for current year cost of care liabilities and therefore does not generally impact net income. Due to the existence of risk sharing and reinvestment provisions in certain customer contracts, principally in the Government contracts, a change in the estimate for medical claims payable does not necessarily result in an equivalent impact on segment profit. The Company believes that the amount of medical claims payable is adequate to cover its ultimate liability for unpaid claims as of December 31, 2019; however, actual claims payments may differ from established estimates. Other medical liabilities consist primarily of amounts payable to pharmacies for claims that have been adjudicated by the Company but not yet paid and “profit share” payables under certain risk-based contracts. Under a contract with profit share provisions, if the cost of care is below certain specified levels, the Company will “share” the cost savings with the customer at the percentages set forth in the contract. In addition, certain contracts include provisions to provide the Company additional funding if the cost of care is above the specified levels. Other medical liabilities also include “reinvestment” payables under certain managed healthcare contracts with Medicaid customers. Under a contract with reinvestment features, if the cost of care is less than certain minimum amounts specified in the contract (usually as a percentage of revenue), the Company is required to “reinvest” such difference in behavioral healthcare programs when and as specified by the customer or to pay the difference to the customer for their use in funding such programs.
Leases	Leases The Company leases certain office space, distribution centers, land and equipment. We assess our contracts to determine if it contains a lease. This assessment is based on (i) the right to control the use of an identified asset; (ii) the right to obtain substantially all of the economic benefits from the use of the identified asset; and (iii) the right to use the identified asset. The Company elected the short-term lease practical expedient; thus, leases with an initial term of twelve months or less are not capitalized and the expense is recognized on a straight-line basis. Most leases include one or more options to renew, with renewal terms that can extend the lease from one Operating leases are included in other long-term assets, accrued liabilities and deferred credits and other long-term liabilities in the consolidated balance sheets. Finance leases are included in property and equipment, current debt, capital lease deferred financing obligations and long-term debt, capital lease and deferred financing obligations in the consolidated balance sheets. ROU assets represent our right to use an underlying asset for the lease term and lease liabilities represent our obligation to make lease payments per the lease. Operating lease ROU assets and liabilities are recognized at lease commencement date based on the present value of lease payments over the lease term. As the rate implicit in most of our leases is not readily determinable, the Company used its incremental borrowing rate to determine the present value of lease payments. The following table shows the components of lease expenses for the year ended December 31, 2019 (in thousands): ​ ​ ​ ​ ​ ​ Year Ended December 31, 2019 Operating lease cost $ 16,781 ​ Finance lease cost: ​ ​ ​ Amortization of right-of-use asset ​ 4,038 ​ Interest on lease liabilities ​ 2,045 ​ Total finance lease cost ​ 6,083 ​ Short-term lease cost ​ 1,227 ​ Variable lease cost ​ 3,243 ​ Total lease cost ​ 27,334 ​ Sublease income ​ (450) ​ Net lease cost $ 26,884 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 Operating leases: ​ ​ Other long-term assets $ 50,460 ​ ​ ​ Accrued liabilities $ 13,211 Deferred credits and other long-term liabilities ​ 45,417 Total operating lease liabilities $ 58,628 ​ ​ ​ Finance leases: ​ ​ Property and equipment, net $ 13,064 ​ ​ ​ Current debt, finance lease and deferred financing obligations $ 4,198 Long-term debt, finance lease and deferred financing obligations ​ 13,878 Total finance lease liabilities $ 18,076 ​ ​ ​ ​ The maturity dates of the Company’s leases as of December 31, 2019 are summarized below (in thousands): ​ ​ ​ ​ ​ December 31, 2019 2020 $ 17,892 2021 ​ 17,319 2022 ​ 16,298 2023 ​ 12,139 2024 ​ 10,302 2025 and beyond ​ 4,658 Total lease payments ​ 78,608 Less interest ​ (1,904) Present value of lease liabilities $ 76,704 ​ ​ ​ ​ The following table shows the weighted average remaining lease term and discount rate as of December 31, 2019: ​ ​ ​ ​ ​ December 31, 2019 Weighted average remaining lease term ​ ​ Operating leases ​ 4.44 Finance leases ​ 4.75 Weighted average discount rate ​ ​ Operating leases ​ 4.79% Finance leases ​ 4.52% ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases $ 17,422 Operating cash flows from finance leases ​ 4,197 Financing cash flows from finance leases ​ 812 Right-of-use asset obtained in exchange for new lease obligation ​ ​ Operating leases ​ 5,831 Finance leases ​ — ​ ​ ​ ​
Accrued Liabilities	Accrued Liabilities As of December 31, 2018, the only individual current liability that exceeded five percent of total current liabilities related to accrued customer settlement liabilities of $93.8 million. As of December 31, 2019, the individual current liabilities that exceeded five percent of total current liabilities related to accrued customer settlement liabilities of $87.5 million and accounts payable rebates of $51.0 million.
Net Income per Common Share attributable to Magellan	Net Income per Common Share attributable to Magellan Net income per common share attributable to Magellan is computed based on the weighted average number of shares of common stock and common stock equivalents outstanding during the period (see Note 6—“Stockholders’ Equity”).
Stock Compensation	Stock Compensation At December 31, 2018 and 2019, the Company had equity-based employee incentive plans, which are described more fully in Note 6—“Stockholders’ Equity”. In addition, the Company issued restricted stock awards (“RSAs”) associated with the Armed Forces Services Corporation (“AFSC”) acquisition, which are also described more fully in Note 6—“Stockholders’ Equity”. The Company recorded stock compensation expense of $39.1 million, $29.5 million and $25.5 million for the years ended December 31, 2017, 2018 and 2019, respectively. As stock compensation expense recognized in the consolidated statements of income for the years ended December 31, 2017, 2018 and 2019 is based on awards ultimately expected to vest, it has been reduced for annual estimated forfeitures of zero to four percent. If the actual number of forfeitures differs from those estimated, additional adjustments to compensation expense may be required in future periods. The Company uses the Black-Scholes-Merton formula to estimate the fair value of substantially all stock options granted to employees. The Company uses the Monte Carlo simulation to derive the fair value of performance-based restricted stock units (“PSUs”) granted to employees. If vesting of an award is conditioned upon the achievement of performance goals, compensation expense during the performance period is estimated using the most probable outcome of the performance goals, and adjusted as the expected outcome changes. The Company recognizes compensation costs for awards that do not contain performance conditions on a straight-line basis over the requisite service period, which is generally the vesting term of three years .

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Summary of Significant Accounting Policies
Summary of impacts of adoption of ASC 842	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at December 31, 2018 Adjustments Due to ASC 842 Balance at January 1, 2019 Assets ​ ​ ​ ​ ​ ​ ​ ​ Deferred income taxes $ 3,411 ​ $ 51 ​ $ 3,462 Other long-term assets ​ 24,530 ​ ​ 59,820 ​ ​ 84,350 Total Assets ​ 2,979,056 ​ ​ 59,871 ​ ​ 3,038,927 ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities and Stockholders' Equity ​ ​ ​ ​ ​ ​ ​ ​ Accrued liabilities ​ 231,356 ​ ​ 13,018 ​ ​ 244,374 Total Current Liabilities ​ 898,893 ​ ​ 13,018 ​ ​ 911,911 Deferred credits and other long-term liabilities ​ 36,483 ​ ​ 46,999 ​ ​ 83,482 Total Liabilities ​ 1,693,753 ​ ​ 60,017 ​ ​ 1,753,770 Retained earnings ​ 1,419,449 ​ ​ (144) ​ ​ 1,419,305 Total Stockholders' Equity ​ 1,285,303 ​ ​ (144) ​ ​ 1,285,159 Total Liabilities and Stockholders' Equity ​ 2,979,056 ​ ​ 59,871 ​ ​ 3,038,927
Schedule of disaggregation of revenue by major service line, type of customer and timing of revenue recognition	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2018 ​ Healthcare Pharmacy Management Elimination Total Major Service Lines ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Behavioral & Specialty Health ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP $ 1,511,532 ​ $ — ​ $ (263) ​ $ 1,511,269 EAP risk-based ​ 349,751 ​ ​ — ​ ​ — ​ ​ 349,751 ASO ​ 247,953 ​ ​ 34,130 ​ ​ (344) ​ ​ 281,739 Magellan Complete Care ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP ​ 2,473,570 ​ ​ — ​ ​ — ​ ​ 2,473,570 ASO ​ 55,816 ​ ​ — ​ ​ — ​ ​ 55,816 PBM, including dispensing ​ — ​ ​ 2,183,151 ​ ​ (189,708) ​ ​ 1,993,443 Medicare Part D ​ — ​ ​ 442,266 ​ ​ — ​ ​ 442,266 PBA ​ — ​ ​ 132,112 ​ ​ — ​ ​ 132,112 Formulary management ​ — ​ ​ 70,900 ​ ​ — ​ ​ 70,900 Other ​ — ​ ​ 3,285 ​ ​ — ​ ​ 3,285 Total net revenue $ 4,638,622 ​ $ 2,865,844 ​ $ (190,315) ​ $ 7,314,151 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Type of Customer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Government $ 3,432,901 ​ $ 946,606 ​ $ — ​ $ 4,379,507 Non-government ​ 1,205,721 ​ ​ 1,919,238 ​ ​ (190,315) ​ ​ 2,934,644 Total net revenue $ 4,638,622 ​ $ 2,865,844 ​ $ (190,315) ​ $ 7,314,151 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Timing of Revenue Recognition ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Transferred at a point in time $ — ​ $ 2,625,417 ​ $ (189,708) ​ $ 2,435,709 Transferred over time ​ 4,638,622 ​ ​ 240,427 ​ ​ (607) ​ ​ 4,878,442 Total net revenue $ 4,638,622 ​ $ 2,865,844 ​ $ (190,315) ​ $ 7,314,151 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2019 ​ Healthcare Pharmacy Management Elimination Total Major Service Lines ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Behavioral & Specialty Health ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP $ 1,504,472 ​ $ — ​ $ (290) ​ $ 1,504,182 EAP risk-based ​ 339,377 ​ ​ — ​ ​ — ​ ​ 339,377 ASO ​ 237,186 ​ ​ 40,348 ​ ​ (302) ​ ​ 277,232 Magellan Complete Care ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Risk-based, non-EAP ​ 2,695,132 ​ ​ — ​ ​ — ​ ​ 2,695,132 ASO ​ 62,379 ​ ​ — ​ ​ — ​ ​ 62,379 PBM, including dispensing ​ — ​ ​ 1,949,225 ​ ​ (180,799) ​ ​ 1,768,426 Medicare Part D ​ — ​ ​ 287,604 ​ ​ — ​ ​ 287,604 PBA ​ — ​ ​ 137,885 ​ ​ — ​ ​ 137,885 Formulary management ​ — ​ ​ 84,567 ​ ​ — ​ ​ 84,567 Other ​ — ​ ​ 2,639 ​ ​ — ​ ​ 2,639 Total net revenue $ 4,838,546 ​ $ 2,502,268 ​ $ (181,391) ​ $ 7,159,423 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Type of Customer ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Government $ 3,674,152 ​ $ 831,673 ​ $ — ​ $ 4,505,825 Non-government ​ 1,164,394 ​ ​ 1,670,595 ​ ​ (181,391) ​ ​ 2,653,598 Total net revenue $ 4,838,546 ​ $ 2,502,268 ​ $ (181,391) ​ $ 7,159,423 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Timing of Revenue Recognition ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Transferred at a point in time $ — ​ $ 2,236,829 ​ $ (180,799) ​ $ 2,056,030 Transferred over time ​ 4,838,546 ​ ​ 265,439 ​ ​ (592) ​ ​ 5,103,393 Total net revenue $ 4,838,546 ​ $ 2,502,268 ​ $ (181,391) ​ $ 7,159,423
Schedule of accounts receivable, contract assets and contract liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ ​ 2018 ​ 2019 ​ $ Change ​ % Change ​ Accounts receivable $ 786,395 ​ $ 915,656 ​ $ 129,261 ​ ​ 16.4% ​ Contract assets ​ 4,647 ​ ​ 2,231 ​ ​ (2,416) ​ ​ (52.0%) ​ Contract liabilities - current ​ 16,853 ​ ​ 6,728 ​ ​ (10,125) ​ ​ (60.1%) ​ Contract liabilities - long-term ​ 13,441 ​ ​ 11,099 ​ ​ (2,342) ​ ​ (17.4%) ​
Schedule of customers generating in excess of ten percent of net revenues for respective segment	In addition to the Massachusetts Contracts, New York Contract and Virginia Contracts previously discussed, the following customers generated in excess of ten percent of net revenues for the respective segment for the respective segment for the years ended December 31, 2017, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Term Date 2017 2018 2019 Healthcare ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Customer A ​ December 31, 2023 ​ $ 605,917 ​ $ 618,227 ​ $ 211,106 * ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Pharmacy Management ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Customer B ​ March 31, 2021 ​ ​ 346,405 ​ ​ 344,479 ​ ​ 335,682 ​ * Revenue amount did not exceed 10 percent of net revenues for the respective segment for the year presented. Amount is shown for comparative purposes only.
Schedule of significant restricted assets	​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 2019 Restricted cash and cash equivalents ​ $ 160,967 ​ $ 146,455 ​ Restricted short-term investments ​ 363,840 ​ 318,464 ​ Restricted deposits (included in other current assets) ​ 43,401 ​ 38,602 ​ Restricted long-term investments ​ 2,854 ​ 10,111 ​ Total ​ $ 571,062 ​ $ 513,632 ​
Schedule of fair value of financial assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 ​ ​ Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents (1) $ — $ 263,462 $ — $ 263,462 ​ Investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Government and agency securities ​ 67,815 ​ — ​ — ​ 67,815 ​ Obligations of government-sponsored enterprises (2) ​ — ​ 5,229 ​ — ​ 5,229 ​ Corporate debt securities ​ — ​ 292,049 ​ — ​ 292,049 ​ Certificates of deposit ​ — ​ 20,650 ​ — ​ 20,650 ​ Total assets held at fair value ​ $ 67,815 ​ $ 581,390 ​ $ — ​ $ 649,205 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ $ — ​ $ — ​ $ 10,124 ​ $ 10,124 ​ Total liabilities held at fair value ​ $ — ​ $ — ​ $ 10,124 ​ $ 10,124 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ Level 1 Level 2 Level 3 Total Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents (3) $ — $ 313,509 $ — $ 313,509 ​ Investments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ U.S. Government and agency securities ​ 104,159 ​ — ​ — ​ 104,159 ​ Corporate debt securities ​ — ​ 239,693 ​ — ​ 239,693 ​ Certificates of deposit ​ — ​ 1,305 ​ — ​ 1,305 ​ Total assets held at fair value ​ $ 104,159 ​ $ 554,507 ​ $ — ​ $ 658,666 ​ (1) Excludes $8.8 million of cash held in bank accounts by the Company. (2) Includes investments in notes issued by the Federal Home Loan Bank, Federal Farm Credit Banks and Federal National Mortgage Association. (3) Excludes $11.7 million of cash held in bank accounts by the Company.
Summary of the liability for contingent consideration	The following table summarizes the Company’s liability for contingent consideration (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ 2018 2019 Balance as of beginning of period ​ $ 8,817 ​ $ 10,124 ​ Changes in fair value ​ 1,307 ​ (2,124) ​ Payments ​ ​ — ​ ​ (8,000) ​ Balance as of end of period ​ $ 10,124 ​ $ — ​
Summary of short-term and long-term investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Estimated ​ Cost Gains Losses Fair Value U.S. Government and agency securities $ 67,870 $ 17 $ (72) $ 67,815 ​ Obligations of government-sponsored enterprises (1) ​ 5,257 ​ — ​ (28) ​ 5,229 ​ Corporate debt securities ​ 292,392 ​ 6 ​ (349) ​ 292,049 ​ Certificates of deposit ​ 20,650 ​ — ​ — ​ 20,650 ​ Total investments at December 31, 2018 ​ $ 386,169 ​ $ 23 ​ $ (449) ​ $ 385,743 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ ​ ​ ​ Gross ​ Gross ​ ​ ​ ​ Amortized ​ Unrealized ​ Unrealized ​ Estimated ​ Cost Gains Losses Fair Value U.S. Government and agency securities $ 104,096 $ 75 $ (12) $ 104,159 ​ Corporate debt securities ​ 239,564 ​ 175 ​ (46) ​ 239,693 ​ Certificates of deposit ​ ​ 1,305 ​ — ​ — ​ 1,305 ​ Total investments at December 31, 2019 ​ $ 344,965 ​ $ 250 ​ $ (58) ​ $ 345,157 ​ (1) Includes investments in notes issued by the Federal Home Loan Bank, Federal National Mortgage Association and Federal Farm Credit Banks.
Summary of maturity dates of investments	The maturity dates of the Company’s investments as of December 31, 2019 are summarized below (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortized Estimated ​ Cost Fair Value 2020 ​ $ 334,304 ​ $ 334,489 ​ 2021 ​ ​ 10,661 ​ ​ 10,668 ​ Total investments at December 31, 2019 $ 344,965 $ 345,157 ​
Schedule of net property and equipment	Property and equipment, net, consisted of the following at December 31, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 2019 Building improvements ​ $ 18,954 ​ $ 18,546 ​ Equipment ​ 201,343 ​ 200,238 ​ Finance leases - property ​ 26,945 ​ 26,945 ​ Finance leases - equipment ​ 24,932 ​ 29,088 ​ Capitalized internal-use software ​ 527,129 ​ 570,989 ​ ​ ​ 799,303 ​ 845,806 ​ Accumulated depreciation ​ (648,555) ​ (707,384) ​ Property and equipment, net ​ $ 150,748 ​ $ 138,422 ​
Schedule of goodwill	2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 ​ 2019 ​ Balance as of beginning of period ​ $ 1,006,288 ​ $ 1,018,156 ​ Other acquisitions and measurement period adjustments ​ 11,868 ​ — ​ Balance as of end of period ​ $ 1,018,156 ​ $ 1,018,156 ​
Schedule of intangible assets	The following is a summary of intangible assets at December 31, 2018 and 2019, and the estimated useful lives for such assets (in thousands, except useful lives): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 ​ ​ ​ ​ ​ ​ ​ ​ Weighted Avg ​ Gross ​ ​ ​ ​ Net ​ ​ Original ​ Remaining ​ Carrying ​ Accumulated ​ Carrying Asset Useful Life ​ Useful Life ​ Amount Amortization Amount Customer agreements and lists 2.5 ​ to 18 ​ years ​ 4.5 years ​ $ 441,346 $ (262,729) $ 178,617 ​ Provider networks and other 1 ​ to 16 ​ years ​ 2.3 years ​ 44,635 ​ (21,789) ​ 22,846 ​ Trade names and licenses ​ indefinite ​ indefinite ​ ​ 30,420 ​ ​ — ​ ​ 30,420 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 516,401 ​ $ (284,518) ​ $ 231,883 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 ​ ​ ​ ​ ​ ​ ​ ​ Weighted Avg ​ Gross ​ ​ ​ ​ Net ​ ​ Original ​ Remaining ​ Carrying ​ Accumulated ​ Carrying Asset Useful Life ​ Useful Life ​ Amount Amortization Amount Customer agreements and lists 2.5 ​ to 18 ​ years ​ 3.4 years ​ $ 441,346 $ (309,296) $ 132,050 ​ Provider networks and other 1 ​ to 16 ​ years ​ 1.6 years ​ 29,752 ​ (24,878) ​ 4,874 ​ Trade names and licenses ​ indefinite ​ indefinite ​ ​ 30,420 ​ ​ — ​ ​ 30,420 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 501,518 ​ $ (334,174) ​ $ 167,344 ​
Schedule of changes in medical claims payable	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Claims payable and IBNR, beginning of period ​ $ 188,618 ​ $ 326,642 ​ $ 394,140 ​ Cost of care: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current year ​ 2,421,270 ​ 3,772,112 ​ 3,962,831 ​ Prior years(3) ​ (7,500) ​ (9,700) ​ (22,300) ​ Total cost of care ​ 2,413,770 ​ 3,762,412 ​ 3,940,531 ​ Claim payments and transfers to other medical liabilities(1): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current year ​ 2,210,346 ​ 3,402,010 ​ 3,594,018 ​ Prior years ​ 161,798 ​ 292,904 ​ 332,650 ​ Total claim payments and transfers to other medical liabilities ​ 2,372,144 ​ 3,694,914 ​ 3,926,668 ​ Acquisition of SWH ​ ​ 96,398 ​ ​ — ​ ​ — ​ Claims payable and IBNR, end of period ​ 326,642 ​ 394,140 ​ 408,003 ​ Withhold (receivables) payable, end of period(2) ​ 983 ​ (593) ​ 1,530 ​ Medical claims payable, end of period ​ $ 327,625 ​ $ 393,547 ​ $ 409,533 ​ (1) For any given period, a portion of unpaid medical claims payable could be covered by risk share or reinvestment liabilities (discussed below) and may not impact the Company’s results of operations for such periods. (2) Medical claims payable is offset by customer withholds from capitation payments in situations in which the customer has the contractual requirement to pay providers for care incurred. (3) Favorable development in 2017, 2018 and 2019 was $7.5 million, $9.7 million and $22.3 million, respectively, and was mainly related to lower medical trends and faster claims completion than originally assumed.
Schedule of leases	​ ​ ​ ​ ​ ​ Year Ended December 31, 2019 Operating lease cost $ 16,781 ​ Finance lease cost: ​ ​ ​ Amortization of right-of-use asset ​ 4,038 ​ Interest on lease liabilities ​ 2,045 ​ Total finance lease cost ​ 6,083 ​ Short-term lease cost ​ 1,227 ​ Variable lease cost ​ 3,243 ​ Total lease cost ​ 27,334 ​ Sublease income ​ (450) ​ Net lease cost $ 26,884 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 Operating leases: ​ ​ Other long-term assets $ 50,460 ​ ​ ​ Accrued liabilities $ 13,211 Deferred credits and other long-term liabilities ​ 45,417 Total operating lease liabilities $ 58,628 ​ ​ ​ Finance leases: ​ ​ Property and equipment, net $ 13,064 ​ ​ ​ Current debt, finance lease and deferred financing obligations $ 4,198 Long-term debt, finance lease and deferred financing obligations ​ 13,878 Total finance lease liabilities $ 18,076 ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2019 Weighted average remaining lease term ​ ​ Operating leases ​ 4.44 Finance leases ​ 4.75 Weighted average discount rate ​ ​ Operating leases ​ 4.79% Finance leases ​ 4.52% ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2019 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ Operating cash flows from operating leases $ 17,422 Operating cash flows from finance leases ​ 4,197 Financing cash flows from finance leases ​ 812 Right-of-use asset obtained in exchange for new lease obligation ​ ​ Operating leases ​ 5,831 Finance leases ​ — ​ ​ ​
Schedule of maturity dates of leases	​ ​ ​ ​ ​ December 31, 2019 2020 $ 17,892 2021 ​ 17,319 2022 ​ 16,298 2023 ​ 12,139 2024 ​ 10,302 2025 and beyond ​ 4,658 Total lease payments ​ 78,608 Less interest ​ (1,904) Present value of lease liabilities $ 76,704 ​ ​ ​

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2019
Stockholders' Equity
Schedule of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 ​ 2018 ​ ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ ​ Exercise ​ ​ ​ Exercise ​ Options Price Options Price Outstanding, beginning of period 2,843,177 $ 57.42 2,458,237 $ 61.50 ​ Granted 525,596 ​ 71.35 477,956 ​ 96.39 ​ Forfeited (79,350) ​ 61.39 (174,376) ​ 80.21 ​ Exercised (831,186) ​ 53.79 (409,208) ​ 56.36 ​ Outstanding, end of period 2,458,237 ​ ​ 61.50 2,352,609 ​ ​ 68.10 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2019 ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ Average ​ ​ ​ ​ ​ ​ Weighted ​ Remaining ​ Aggregate ​ ​ ​ ​ ​ Average ​ Contractual ​ Intrinsic ​ ​ ​ ​ ​ Exercise ​ Term ​ Value ​ Options Price (in years) (in thousands) Outstanding, beginning of period 2,352,609 ​ $ 68.10 ​ ​ Granted 429,124 ​ ​ 66.22 ​ ​ ​ ​ ​ ​ Forfeited (112,120) ​ 78.18 ​ ​ ​ ​ ​ ​ Exercised (543,752) ​ 60.16 ​ ​ ​ ​ ​ ​ Outstanding, end of period 2,125,861 ​ $ 69.22 5.13 ​ $ 26,773 ​ Vested and expected to vest at end of period 2,116,787 ​ $ 69.20 5.12 ​ $ 26,689 ​ Exercisable, end of period 1,607,321 ​ $ 67.18 3.99 ​ $ 22,470 ​
Schedule of weighted average assumptions used to determine weighted average grant date fair value	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Risk-free interest rate 1.79 % 2.54 % 2.50 % Expected life 4 years 4 years 4 years Expected volatility 27.75 % 28.20 % 35.56 % Expected dividend yield 0.00 % 0.00 % 0.00 %
Schedule of nonvested restricted stock award activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 ​ 2018 ​ 2019 ​ ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ Shares Fair Value Shares Fair Value Shares Fair Value Outstanding, beginning of period 615,472 $ 58.71 31,102 $ 68.00 11,795 ​ $ 89.05 ​ Awarded 14,959 ​ 70.20 11,795 ​ 89.05 41,905 ​ 65.60 ​ Vested (585,438) ​ 58.33 (31,102) ​ 68.00 (13,939) ​ 85.99 ​ Forfeited (13,891) ​ 65.97 — ​ — — ​ — ​ Outstanding, ending of period 31,102 ​ ​ 68.00 11,795 ​ ​ 89.05 39,761 ​ ​ 65.40 ​
Schedule of nonvested restricted stock units	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 ​ 2018 ​ 2019 ​ ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ Shares Fair Value Shares Fair Value Shares Fair Value Outstanding, beginning of period 200,178 $ 61.65 163,289 $ 66.46 156,750 ​ $ 86.68 ​ Awarded 107,417 ​ 68.53 111,033 ​ 99.29 212,065 ​ 67.92 ​ Vested (119,489) ​ 60.38 (84,627) ​ 65.20 (68,993) ​ 81.95 ​ Forfeited (24,817) ​ 65.87 (32,945) ​ 84.17 (43,392) ​ 76.71 ​ Outstanding, ending of period ​ 163,289 ​ ​ 66.46 156,750 ​ ​ 86.68 256,430 ​ ​ 74.12 ​
Summary of nonvested performance-based restricted stock units	Summarized information related to the Company’s nonvested PSUs for the years ended December 31, 2017, 2018 and 2019 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ Weighted ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ ​ Shares ​ Fair Value ​ Shares ​ Fair Value ​ Shares ​ Fair Value Outstanding, beginning of period ​ 102,977 ​ $ 93.03 ​ 202,315 ​ $ 84.63 ​ 209,019 ​ $ 103.38 ​ Awarded ​ 101,989 ​ 76.24 ​ 80,502 ​ 141.61 ​ 101,498 ​ 101.82 ​ Vested ​ — ​ — ​ (33,592) ​ 85.00 ​ (43,109) ​ 97.12 ​ Forfeited ​ (2,651) ​ 87.75 ​ (40,206) ​ 100.96 ​ (18,849) ​ 97.49 ​ Outstanding, end of period ​ 202,315 ​ 84.63 ​ 209,019 ​ 103.38 ​ 248,559 ​ 104.27 ​
Schedule of computation of basic and diluted earnings per share	The following table reconciles income (numerator) and shares (denominator) used in the Company’s computations of net income per share for the years ended December 31, 2017, 2018 and 2019 (in thousands, except per share data): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 ​ Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income ​ $ 110,207 ​ $ 24,181 ​ $ 55,902 ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of common shares outstanding—basic ​ 23,333 ​ 24,349 ​ 24,243 ​ Common stock equivalents—stock options ​ 530 ​ 493 ​ 142 ​ Common stock equivalents—RSAs ​ 376 ​ 15 ​ 8 ​ Common stock equivalents—RSUs ​ 64 ​ 37 ​ 35 ​ Common stock equivalents—PSUs ​ ​ 134 ​ ​ 137 ​ ​ 131 ​ Common stock equivalents—employee stock purchase plan ​ 3 ​ 4 ​ 4 ​ Weighted average number of common shares outstanding—diluted ​ 24,440 ​ 25,035 ​ 24,563 ​ Net income per common share—basic ​ $ 4.72 ​ $ 0.99 ​ $ 2.31 ​ Net income per common share—diluted ​ $ 4.51 ​ $ 0.97 ​ $ 2.28 ​
Schedule of stock repurchases made	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Number ​ Average ​ ​ ​ ​ ​ ​ of Shares ​ Price Paid ​ Aggregate ​ Period Purchased per Share Cost October 26, 2015 - December 31, 2015 ​ 345,044 ​ $ 53.46 ​ $ 18.4 ​ January 1, 2016 - December 31, 2016 ​ 1,828,183 ​ ​ 58.40 ​ ​ 106.8 ​ January 1, 2017 - December 31, 2017 ​ 280,140 ​ ​ 77.67 ​ ​ 21.8 ​ January 1, 2018 - December 31, 2018 ​ 844,872 ​ ​ 74.59 ​ ​ 63.0 ​ January 1, 2019 - December 31, 2019 ​ 60,901 ​ ​ 61.15 ​ ​ 3.7 ​ ​ ​ 3,359,140 ​ ​ ​ ​ $ 213.7 ​

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Taxes
Schedule of components of income tax expense (benefit)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Income taxes currently payable: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ $ 49,944 ​ $ 13,593 ​ $ 13,144 ​ State ​ 6,120 ​ 7,145 ​ 4,719 ​ ​ ​ 56,064 ​ 20,738 ​ 17,863 ​ Deferred income taxes (benefits): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ (31,941) ​ 307 ​ 6,061 ​ State ​ 960 ​ (2,032) ​ 991 ​ ​ ​ (30,981) ​ (1,725) ​ 7,052 ​ Total income tax expense ​ $ 25,083 ​ $ 19,013 ​ $ 24,915 ​
Schedule of differences between total income tax expense and amount computed using the statutory federal income tax rate	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Income tax expense at federal statutory rate ​ $ 47,328 ​ $ 9,071 ​ $ 16,972 ​ State income taxes, net of federal income tax benefit ​ 4,993 ​ 2,968 ​ 4,761 ​ State contingencies added ​ ​ 2,161 ​ ​ 3,644 ​ ​ 1,178 ​ Tax contingencies reversed due to statute closings ​ (2,044) ​ (2,651) ​ (3,115) ​ Change in valuation allowances ​ ​ (14,973) ​ ​ (691) ​ ​ 584 ​ Adjustments for Tax Act ​ ​ (8,677) ​ ​ 335 ​ ​ — ​ Share-based compensation ​ ​ (4,724) ​ ​ (4,750) ​ ​ 1,737 ​ Qualified research credit ​ ​ (1,325) ​ ​ (1,781) ​ ​ (1,594) ​ Non-deductible executive compensation ​ ​ 104 ​ ​ 3,052 ​ ​ 3,153 ​ Non-deductible HIF fees ​ ​ — ​ ​ 8,246 ​ ​ — ​ Other-net ​ 2,240 ​ 1,570 ​ 1,239 ​ Total income tax expense ​ $ 25,083 ​ $ 19,013 ​ $ 24,915 ​
Schedule of components of deferred tax assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2018 2019 Deferred tax assets: ​ ​ ​ ​ ​ ​ ​ Net operating loss carryforwards ​ $ 11,159 ​ $ 8,417 ​ Share-based compensation ​ 10,299 ​ 9,167 ​ Other accrued compensation ​ 5,508 ​ 10,697 ​ Claims reserves ​ 7,053 ​ 5,355 ​ Deferred revenue ​ ​ 4,368 ​ ​ 4,122 ​ Other non-deductible accrued liabilities ​ 6,057 ​ 3,267 ​ Indirect tax benefits ​ ​ 3,296 ​ ​ 3,011 ​ Operating lease--right-of-use liabilities ​ ​ — ​ ​ 18,632 ​ Other deferred tax assets ​ 2,130 ​ 111 ​ Total deferred tax assets ​ 49,870 ​ 62,779 ​ Valuation allowances ​ (1,521) ​ (2,105) ​ Deferred tax assets after valuation allowances ​ 48,349 ​ 60,674 ​ Deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ Depreciation ​ (21,350) ​ (20,577) ​ Amortization of goodwill and intangible assets ​ ​ (30,463) ​ ​ (33,073) ​ Operating lease--right-of-use assets ​ ​ — ​ ​ (16,656) ​ Other deferred tax liabilities ​ (4,292) ​ (5,562) ​ Total deferred tax liabilities ​ (56,105) ​ (75,868) ​ Net deferred tax liabilities ​ $ (7,756) ​ $ (15,194) ​
Schedule of reconciliation of the beginning and ending amount of gross unrecognized tax benefits	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Balance as of beginning of period ​ $ 13,604 ​ $ 13,580 ​ $ 15,683 ​ Additions for current year tax positions ​ 3,243 ​ 4,955 ​ 1,492 ​ Additions for tax positions of prior years ​ 342 ​ 512 ​ 699 ​ Reductions for tax positions of prior years ​ (114) ​ (398) ​ (472) ​ Reductions due to lapses of applicable statutes of limitations ​ (2,693) ​ (3,005) ​ (3,489) ​ Changes due to Tax Act ​ ​ (509) ​ ​ 339 ​ ​ — ​ Reductions due to settlements with taxing authorities ​ (293) ​ (300) ​ (43) ​ Balance as of end of period ​ $ 13,580 ​ $ 15,683 ​ $ 13,870 ​

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Information
Schedule of supplemental cash flow information	Supplemental cash flow information for the years ended December 31, 2017, 2018 and 2019 is as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 Income taxes paid, net of refunds ​ $ 59,474 ​ $ 40,179 ​ $ 4,774 ​ Interest paid ​ $ 15,415 ​ $ 34,223 ​ $ 29,892 ​ Assets acquired through capital leases and deferred financing ​ $ 2,418 ​ $ 20,576 ​ $ 3,302 ​

Business Segment Information (T

Business Segment Information (Tables)	12 Months Ended
	Dec. 31, 2019
Business Segment Information
Schedule of operating results by business segment	The following tables summarize, for the periods indicated, operating results by business segment for the years ended December 31, 2017, 2018 and 2019 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate ​ ​ ​ ​ ​ ​ ​ Pharmacy ​ and ​ ​ ​ ​ Healthcare Management Elimination Consolidated Year Ended December 31, 2017 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Managed care and other revenue ​ $ 3,206,277 ​ $ 273,489 ​ $ (584) ​ $ 3,479,182 ​ PBM and dispensing revenue ​ — ​ 2,491,044 ​ (131,643) ​ 2,359,401 ​ Cost of care ​ (2,413,770) ​ — ​ — ​ (2,413,770) ​ Cost of goods sold ​ — ​ (2,341,979) ​ 130,069 ​ (2,211,910) ​ Direct service costs and other ​ (601,201) ​ (302,525) ​ (38,157) ​ (941,883) ​ Stock compensation expense (1) ​ ​ 10,689 ​ ​ 19,881 ​ ​ 8,546 ​ ​ 39,116 ​ Changes in fair value of contingent consideration (1) ​ ​ 696 ​ ​ — ​ ​ — ​ ​ 696 ​ Less: non-controlling interest segment loss (2) ​ (56) ​ — ​ (3) ​ (59) ​ Segment profit (loss) ​ $ 202,747 ​ $ 139,910 ​ $ (31,766) ​ $ 310,891 ​ Identifiable assets by business segment (3) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Restricted cash ​ $ 220,786 ​ $ 8,059 ​ $ 168 ​ $ 229,013 ​ Net accounts receivable ​ 244,486 ​ 403,880 ​ 12,409 ​ 660,775 ​ Investments ​ 327,865 ​ — ​ — ​ 327,865 ​ Pharmaceutical inventory ​ — ​ 40,945 ​ — ​ 40,945 ​ Goodwill ​ 610,867 ​ 395,421 ​ — ​ 1,006,288 ​ Other intangible assets, net ​ 165,159 ​ 103,129 ​ — ​ 268,288 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate ​ ​ ​ ​ ​ ​ ​ Pharmacy ​ and ​ ​ ​ ​ Healthcare Management Elimination Consolidated Year Ended December 31, 2018 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Managed care and other revenue ​ $ 4,638,622 ​ $ 240,427 ​ $ (607) ​ $ 4,878,442 ​ PBM revenue ​ — ​ 2,625,417 ​ (189,708) ​ 2,435,709 ​ Cost of care ​ (3,762,412) ​ — ​ — ​ (3,762,412) ​ Cost of goods sold ​ — ​ (2,468,170) ​ 185,148 ​ (2,283,022) ​ Direct service costs and other ​ (735,366) ​ (298,713) ​ (37,456) ​ (1,071,535) ​ Stock compensation expense (1) ​ 6,982 ​ 5,458 ​ 17,032 ​ 29,472 ​ Changes in fair value of contingent consideration (1) ​ ​ 1,307 ​ ​ — ​ ​ — ​ ​ 1,307 ​ Segment Profit (Loss) ​ $ 149,133 ​ $ 104,419 ​ $ (25,591) ​ $ 227,961 ​ Identifiable assets by business segment (3) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Restricted cash ​ $ 157,437 ​ $ 576 ​ $ 2,954 ​ $ 160,967 ​ Net accounts receivable ​ 290,564 ​ 465,345 ​ 150 ​ 756,059 ​ Investments ​ 378,706 ​ 7,037 ​ — ​ 385,743 ​ Pharmaceutical inventory ​ — ​ 40,818 ​ — ​ 40,818 ​ Goodwill ​ 622,604 ​ 395,552 ​ — ​ 1,018,156 ​ Other intangible assets, net ​ 136,644 ​ 82,072 ​ 13,167 ​ 231,883 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Corporate ​ ​ ​ ​ ​ ​ ​ Pharmacy ​ and ​ ​ ​ ​ Healthcare Management Elimination Consolidated Year Ended December 31, 2019 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Managed care and other revenue ​ $ 4,838,546 ​ $ 265,439 ​ $ (592) ​ $ 5,103,393 ​ PBM revenue ​ — ​ 2,236,829 ​ (180,799) ​ 2,056,030 ​ Cost of care ​ (3,940,531) ​ — ​ — ​ (3,940,531) ​ Cost of goods sold ​ — ​ (2,076,509) ​ 177,638 ​ (1,898,871) ​ Direct service costs and other ​ (726,937) ​ (323,162) ​ (40,632) ​ (1,090,731) ​ Stock compensation expense (1) ​ 8,467 ​ 7,834 ​ 9,200 ​ 25,501 ​ Changes in fair value of contingent consideration (1) ​ ​ (2,124) ​ ​ — ​ ​ — ​ ​ (2,124) ​ Segment Profit (Loss) ​ $ 177,421 ​ $ 110,431 ​ $ (35,185) ​ $ 252,667 ​ Identifiable assets by business segment (3) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Restricted cash ​ $ 144,229 ​ $ 2,226 ​ $ — ​ $ 146,455 ​ Net accounts receivable ​ 410,958 ​ 478,627 ​ 480 ​ 890,065 ​ Investments ​ 338,439 ​ 6,718 ​ — ​ 345,157 ​ Pharmaceutical inventory ​ — ​ 44,962 ​ — ​ 44,962 ​ Goodwill ​ 622,604 ​ 395,552 ​ — ​ 1,018,156 ​ Other intangible assets, net ​ 105,728 ​ 61,536 ​ 80 ​ 167,344 ​ (1) Stock compensation expense, changes in the fair value of contingent consideration recorded in relation to the acquisitions and impairment of intangible assets are included in direct service costs and other operating expenses; however, these amounts are excluded from the computation of Segment Profit. (2) The non-controlling interest portion of AlphaCare’s segment loss is excluded from the computation of Segment Profit in 2017. (3) Identifiable assets by business segment are those assets that are used in the operations of each segment. The remainder of the Company’s assets cannot be specifically identified by segment.
Schedule of reconciliation of Segment Profit to income before income taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2017 2018 2019 ​ Income before income taxes $ 135,224 ​ $ 43,194 ​ $ 80,817 ​ Stock compensation expense 39,116 ​ 29,472 ​ 25,501 ​ Changes in fair value of contingent consideration ​ 696 ​ ​ 1,307 ​ ​ (2,124) ​ Non-controlling interest segment loss ​ 59 ​ ​ — ​ ​ — ​ Depreciation and amortization 115,706 ​ 132,660 ​ 131,509 ​ Interest expense 25,977 ​ 35,396 ​ 36,153 ​ Interest and other income (5,887) ​ (14,068) ​ (19,189) ​ Segment Profit $ 310,891 ​ $ 227,961 ​ $ 252,667 ​

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Selected Quarterly Financial Data (Unaudited)
Summary of unaudited quarterly results of operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Quarter Ended ​ ​ March 31, ​ June 30, ​ September 30, ​ December 31, ​ 2018 2018 2018 2018 Year Ended December 31, 2018 ​ ​ ​ ​ ​ Net revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Managed care and other ​ $ 1,219,763 ​ $ 1,215,340 ​ $ 1,235,787 ​ $ 1,207,552 ​ PBM and dispensing ​ 585,314 ​ 595,583 ​ 617,719 ​ 637,093 ​ Total net revenue ​ 1,805,077 ​ 1,810,923 ​ 1,853,506 ​ 1,844,645 ​ Costs and expenses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of care ​ 928,661 ​ 935,814 ​ 938,031 ​ 959,906 ​ Cost of goods sold ​ 559,665 ​ 558,419 ​ 571,145 ​ 593,793 ​ Direct service costs and other operating expenses (1) (2) ​ 269,077 ​ 259,152 ​ 265,471 ​ 277,835 ​ Depreciation and amortization ​ 30,407 ​ 33,848 ​ 33,047 ​ 35,358 ​ Interest expense ​ 8,366 ​ 8,678 ​ 8,990 ​ 9,362 ​ Interest and other income ​ (2,476) ​ (3,363) ​ (4,139) ​ (4,090) ​ Total costs and expenses ​ 1,793,700 ​ 1,792,548 ​ 1,812,545 ​ 1,872,164 ​ Income (loss) before income taxes ​ 11,377 ​ 18,375 ​ 40,961 ​ (27,519) ​ Provision (benefit) for income taxes ​ (75) ​ 4,824 ​ 13,816 ​ 448 ​ Net income (loss) attributable to Magellan ​ $ 11,452 ​ $ 13,551 ​ $ 27,145 ​ $ (27,967) ​ Weighted average number of common shares outstanding—basic ​ 24,349 ​ ​ 24,569 ​ ​ 24,433 ​ ​ 24,048 ​ Weighted average number of common shares outstanding—diluted ​ 25,612 ​ ​ 25,407 ​ ​ 24,928 ​ ​ 24,048 ​ Net income (loss) per common share attributable to Magellan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) per common share—basic: ​ $ 0.47 ​ $ 0.55 ​ $ 1.11 ​ $ (1.16) ​ Net income (loss) per common share—diluted: ​ $ 0.45 ​ $ 0.53 ​ $ 1.09 ​ $ (1.16) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Quarter Ended ​ ​ March 31, ​ June 30, ​ September 30, ​ December 31, ​ 2019 2019 2019 2019 Year Ended December 31, 2019 ​ ​ ​ ​ ​ Net revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Managed care and other ​ $ 1,223,979 ​ $ 1,283,143 ​ $ 1,303,936 ​ $ 1,292,335 ​ PBM and dispensing ​ 515,510 ​ 505,193 ​ 525,005 ​ 510,322 ​ Total net revenue ​ 1,739,489 ​ 1,788,336 ​ 1,828,941 ​ 1,802,657 ​ Costs and expenses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost of care ​ 941,961 ​ 1,001,886 ​ 1,013,006 ​ 983,678 ​ Cost of goods sold ​ 489,793 ​ 461,187 ​ 482,277 ​ 465,614 ​ Direct service costs and other operating expenses (3)(4) ​ 271,924 ​ 266,434 ​ 266,322 ​ 286,051 ​ Depreciation and amortization ​ 30,708 ​ 33,490 ​ 34,157 ​ 33,154 ​ Interest expense ​ 9,107 ​ 9,141 ​ 9,007 ​ 8,898 ​ Interest and other income ​ (4,974) ​ (5,021) ​ (4,970) ​ (4,224) ​ Total costs and expenses ​ 1,738,519 ​ 1,767,117 ​ 1,799,799 ​ 1,773,171 ​ Income before income taxes ​ 970 ​ 21,219 ​ 29,142 ​ 29,486 ​ Provision for income taxes ​ 539 ​ 7,606 ​ 7,868 ​ 8,902 ​ Net income attributable to Magellan ​ ​ 431 ​ ​ 13,613 ​ ​ 21,274 ​ ​ 20,584 ​ Weighted average number of common shares outstanding—basic ​ ​ 23,946 ​ ​ 24,101 ​ ​ 24,426 ​ ​ 24,491 ​ Weighted average number of common shares outstanding—diluted ​ ​ 24,213 ​ ​ 24,416 ​ ​ 24,708 ​ ​ 24,905 ​ Net income per common share attributable to Magellan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income per common share—basic: ​ $ 0.02 ​ $ 0.56 ​ $ 0.87 ​ $ 0.84 ​ Net income per common share—diluted: ​ $ 0.02 ​ $ 0.56 ​ $ 0.86 ​ $ 0.83 ​ ​ (1) Includes stock compensation expense of $7,646, $10,439 , $9,320 and $2,067 for the quarters ended March 31, June 30, September 30 and December 31, 2018, respectively. (2) Includes changes in fair value of contingent consideration of $233, $70, $148 and $856 for the quarters ended March 31, June 30, September 30 and December 31, 2018, respectively. (3) Includes stock compensation expense of $9,607, $5,414 , $4,811 and $5,669 for the quarters ended March 31, June 30, September 30 and December 31, 2019, respectively. (4) Includes changes in fair value of contingent consideration of $144, $(2,149), $4 and $(123) for the quarters ended March 31, June 30, September 30 and December 31, 2019, respectively.

General (Details)

General (Details) - segment	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
General
Number of segments	3	3	3
Number of reporting units	3	3	3
Healthcare
General
Number of reporting units	2	2	2

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Recent Accounting Pronouncements - General Information (Details)	12 Months Ended
	Dec. 31, 2019
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	true
Change in Accounting Principle, Accounting Standards Update, Early Adoption	false
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 1, 2019
Change in Accounting Principle, Accounting Standards Update, Transition Option Elected	Modified Retrospective
New Accounting Pronouncement or Change in Accounting Principle, Prior Period Not Restated	true
Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	false
Change in Accounting Principle, Accounting Standards Update, Early Adoption	false
Accounting Standards Update 2017-04
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	false
Change in Accounting Principle, Accounting Standards Update, Early Adoption	false
Accounting Standards Update 2018-15
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted	false
Change in Accounting Principle, Accounting Standards Update, Early Adoption	false

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Recent Accounting Pronouncements - Leases - Practical Expedients (Details)	12 Months Ended
	Dec. 31, 2019
Summary of Significant Accounting Policies
Election of package of practical expedients	true

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Recent Accounting Pronouncements - Leases - Adoption of ASC 842 (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Leases
Operating lease right-of-use assets	$ 50,460	$ 59,800
Lease liabilities	$ 76,704	$ 67,900

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Cumulative Effect of Changes (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets
Deferred income taxes	$ 1,840	$ 3,462	$ 3,411
Other long-term assets	82,700	84,350	24,530
Total Assets	3,092,173	3,038,927	2,979,056
Liabilities and Stockholders' Equity
Accrued liabilities	284,024	244,374	231,356
Total Current Liabilities	910,147	911,911	898,893
Deferred credits and other long-term liabilities	73,243	83,482	36,483
Total Liabilities	1,694,390	1,753,770	1,693,753
Retained earnings	1,475,207	1,419,305	1,419,449
Total Stockholders' Equity	1,397,783	1,285,159	1,285,303
Total Liabilities and Stockholders' Equity	$ 3,092,173	3,038,927	$ 2,979,056
Accounting Standards Update 2016-02 | Restatement Adjustment
Assets
Deferred income taxes		51
Other long-term assets		59,820
Total Assets		59,871
Liabilities and Stockholders' Equity
Accrued liabilities		13,018
Total Current Liabilities		13,018
Deferred credits and other long-term liabilities		46,999
Total Liabilities		60,017
Retained earnings		(144)
Total Stockholders' Equity		(144)
Total Liabilities and Stockholders' Equity		$ 59,871

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating results by business segment
Net revenue	$ 1,802,657	$ 1,828,941	$ 1,788,336	$ 1,739,489	$ 1,844,645	$ 1,853,506	$ 1,810,923	$ 1,805,077	$ 7,159,423	$ 7,314,151	$ 5,838,583
Transferred at a point in time
Operating results by business segment
Net revenue									2,056,030	2,435,709
Transferred over time
Operating results by business segment
Net revenue									5,103,393	4,878,442
Government
Operating results by business segment
Net revenue									4,505,825	4,379,507
Non-government
Operating results by business segment
Net revenue									2,653,598	2,934,644
Behavioral & Specialty Health, risk-based, non-EAP
Operating results by business segment
Net revenue									1,504,182	1,511,269
Behavioral & Specialty Health, EAP risk-based
Operating results by business segment
Net revenue									339,377	349,751
Behavioral & Specialty Health, ASO
Operating results by business segment
Net revenue									277,232	281,739
Magellan Complete Care, risk-based, non-EAP
Operating results by business segment
Net revenue									2,695,132	2,473,570
Magellan Complete Care, ASO
Operating results by business segment
Net revenue									62,379	55,816
PBM, including dispensing
Operating results by business segment
Net revenue									1,768,426	1,993,443
Medicare Part D
Operating results by business segment
Net revenue									287,604	442,266
PBA
Operating results by business segment
Net revenue									137,885	132,112
Formulary management
Operating results by business segment
Net revenue									84,567	70,900
Other service lines
Operating results by business segment
Net revenue									2,639	3,285
Healthcare
Operating results by business segment
Net revenue									4,838,546	4,638,622
Healthcare | Transferred over time
Operating results by business segment
Net revenue									4,838,546	4,638,622
Healthcare | Government
Operating results by business segment
Net revenue									3,674,152	3,432,901
Healthcare | Non-government
Operating results by business segment
Net revenue									1,164,394	1,205,721
Healthcare | Behavioral & Specialty Health, risk-based, non-EAP
Operating results by business segment
Net revenue									1,504,472	1,511,532
Healthcare | Behavioral & Specialty Health, EAP risk-based
Operating results by business segment
Net revenue									339,377	349,751
Healthcare | Behavioral & Specialty Health, ASO
Operating results by business segment
Net revenue									237,186	247,953
Healthcare | Magellan Complete Care, risk-based, non-EAP
Operating results by business segment
Net revenue									2,695,132	2,473,570
Healthcare | Magellan Complete Care, ASO
Operating results by business segment
Net revenue									62,379	55,816
Pharmacy Management
Operating results by business segment
Net revenue									2,502,268	2,865,844
Pharmacy Management | Transferred at a point in time
Operating results by business segment
Net revenue									2,236,829	2,625,417
Pharmacy Management | Transferred over time
Operating results by business segment
Net revenue									265,439	240,427
Pharmacy Management | Government
Operating results by business segment
Net revenue									831,673	946,606
Pharmacy Management | Non-government
Operating results by business segment
Net revenue									1,670,595	1,919,238
Pharmacy Management | Behavioral & Specialty Health, ASO
Operating results by business segment
Net revenue									40,348	34,130
Pharmacy Management | PBM, including dispensing
Operating results by business segment
Net revenue									1,949,225	2,183,151
Pharmacy Management | Medicare Part D
Operating results by business segment
Net revenue									287,604	442,266
Pharmacy Management | PBA
Operating results by business segment
Net revenue									137,885	132,112
Pharmacy Management | Formulary management
Operating results by business segment
Net revenue									84,567	70,900
Pharmacy Management | Other service lines
Operating results by business segment
Net revenue									2,639	3,285
Elimination
Operating results by business segment
Net revenue									(181,391)	(190,315)
Elimination | Transferred at a point in time
Operating results by business segment
Net revenue									(180,799)	(189,708)
Elimination | Transferred over time
Operating results by business segment
Net revenue									(592)	(607)
Elimination | Non-government
Operating results by business segment
Net revenue									(181,391)	(190,315)
Elimination | Behavioral & Specialty Health, risk-based, non-EAP
Operating results by business segment
Net revenue									(290)	(263)
Elimination | Behavioral & Specialty Health, ASO
Operating results by business segment
Net revenue									(302)	(344)
Elimination | PBM, including dispensing
Operating results by business segment
Net revenue									$ (180,799)	$ (189,708)

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Per Member Per Month Revenue (Details)	12 Months Ended
	Dec. 31, 2019
Operating results by business segment
Required notice to terminate PMPM contract	30 days
Minimum
Operating results by business segment
Term of PMPM contract	1 year

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Pharmacy Benefit Management Revenue (Details)	12 Months Ended
	Dec. 31, 2019
Minimum
Operating results by business segment
Expected term of PBM relationship	1 year

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Pharmacy Benefit Administration Revenue (Details)	12 Months Ended
	Dec. 31, 2019
Minimum
Operating results by business segment
Anticipated period of benefit of the material right	2 years
Maximum
Operating results by business segment
Anticipated period of benefit of the material right	10 years

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Formulary Management Revenue (Details)	12 Months Ended
	Dec. 31, 2019
Minimum
Operating results by business segment
Term of formulary management contract	1 year

Summary of Significant Accou_13

Summary of Significant Accounting Policies - Accounts Receivable, Contract Assets and Contract Liabilities - Tabular Disclosure (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Summary of Significant Accounting Policies
Accounts receivable	$ 915,656	$ 786,395
Change in accounts receivable	$ 129,261
Change in accounts receivable (as a percent)	16.40%
Contract assets	$ 2,231	4,647
Change in contract assets	$ 2,416
Change in contract assets (as a percent)	(52.00%)
Contract liabilities - current	$ 6,728	16,853
Change in contract liabilities - current	$ (10,125)
Change in contract liabilities - current (as a percent)	(60.10%)
Contract liabilities - long-term	$ 11,099	$ 13,441
Change in contract liabilities - long-term	$ (2,342)
Change in contract liabilities - long-term (as a percent)	(17.40%)

Summary of Significant Accou_14

Summary of Significant Accounting Policies - Accounts Receivable, Contract Assets and Contract Liabilities - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Contract liabilities
Revenue recognized previously included in current contract liabilities	$ 16.7

Summary of Significant Accou_15

Summary of Significant Accounting Policies - Accounts Receivable, Contract Assets and Contract Liabilities - Performance Obligation (Details) $ in Millions	Dec. 31, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Performance obligation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Estimated revenue to be recognized	$ 6.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Performance obligation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Estimated revenue to be recognized	$ 3.2
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Performance obligation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Estimated revenue to be recognized	$ 2.8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Performance obligation
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	0 months
Estimated revenue to be recognized	$ 5.1

Summary of Significant Accou_16

Summary of Significant Accounting Policies - Customers Exceeding Ten Percent of Consolidated Net Revenues (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019USD ($)item	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)item	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Significant customers
Revenues	$ 1,802,657	$ 1,828,941	$ 1,788,336	$ 1,739,489	$ 1,844,645	$ 1,853,506	$ 1,810,923	$ 1,805,077	$ 7,159,423	$ 7,314,151	$ 5,838,583
Maximum
Significant customers
Term of contracts with customers									3 years
Number of contract extensions or renewals | item	5								5
Term of contract extensions or renewals									2 years
Virginia Contracts
Significant customers
Revenues									$ 847,800	476,700	73,800
CCC Plus Contract
Significant customers
Term of contracts with customers									5 years
Term of contract extensions or renewals									12 months
Termination notice									90 days
CCC Plus Contract | Maximum
Significant customers
Number of contract extensions or renewals | item	5								5
Medallion Contract
Significant customers
Term of contract extensions or renewals									12 months
Termination notice									180 days
Medallion Contract | Maximum
Significant customers
Number of contract extensions or renewals | item	6								6
New York Contract
Significant customers
Revenues									$ 836,400	691,600	265,200
Massachusetts Contracts
Significant customers
Revenues									$ 718,900	$ 682,100	$ 109,100
SCO Contract
Significant customers
Term of contract extensions or renewals									1 year
Termination notice									180 days
CMS Contract
Significant customers
Term of contracts with customers									1 year

Summary of Significant Accou_17

Summary of Significant Accounting Policies - Customers Exceeding Ten Percent of Segment Revenues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Significant customers
Revenues	$ 1,802,657	$ 1,828,941	$ 1,788,336	$ 1,739,489	$ 1,844,645	$ 1,853,506	$ 1,810,923	$ 1,805,077	$ 7,159,423	$ 7,314,151	$ 5,838,583
Healthcare
Significant customers
Revenues									4,838,546	4,638,622
Healthcare | Customer A
Significant customers
Revenues									211,106	618,227	605,917
Pharmacy Management
Significant customers
Revenues									2,502,268	2,865,844
Pharmacy Management | Customer B
Significant customers
Revenues									$ 335,682	$ 344,479	$ 346,405

Summary of Significant Accou_18

Summary of Significant Accounting Policies - Concentration of Business (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Significant customers
Net revenue	$ 1,802,657	$ 1,828,941	$ 1,788,336	$ 1,739,489	$ 1,844,645	$ 1,853,506	$ 1,810,923	$ 1,805,077	$ 7,159,423	$ 7,314,151	$ 5,838,583
Minimum
Significant customers
Term of contracts with customers									1 year
Term of contract extensions or renewals									1 year
Notice period for termination of contract									30 days
Maximum
Significant customers
Term of contracts with customers									3 years
Term of contract extensions or renewals									2 years
Notice period for termination of contract									180 days
Pennsylvania Counties
Significant customers
Net revenue									$ 537,800	544,600	490,000
CMS
Significant customers
Net revenue									287,600	442,300	511,000
United States federal government
Significant customers
Net revenue									$ 299,200	$ 308,700	$ 341,500

Summary of Significant Accou_19

Summary of Significant Accounting Policies - Health Care Reform (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Summary of Significant Accounting Policies
HIF fees	$ 29.9

Summary of Significant Accou_20

Summary of Significant Accounting Policies - Cash And Cash Equivalents (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Cash and Cash Equivalents
Book overdrafts	$ 0.5	$ 0
Excess capital and undistributed earnings for regulated subsidiaries included in cash and cash equivalents	$ 134.8

Summary of Significant Accou_21

Summary of Significant Accounting Policies - Restricted Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restricted Assets
Restricted cash and cash equivalents	$ 146,455	$ 160,967	$ 229,013
Restricted short-term investments	318,464	363,840
Restricted deposits (included in other current assets)	38,602	43,401
Restricted long-term investments	10,111	2,854
Total	$ 513,632	$ 571,062
Equity in restricted net assets of consolidated subsidiaries as a percentage of consolidated stockholders' equity (as a percent)	28.10%

Summary of Significant Accou_22

Summary of Significant Accounting Policies - Fair Value Measurements - Assets and Liabilities - Tabular Disclosure (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Investments	$ 345,157	$ 385,743	$ 327,865
U.S. Government and agency securities
Assets
Investments	104,159	67,815
Obligations of government-sponsored enterprises
Assets
Investments		5,229
Corporate debt securities
Assets
Investments	239,693	292,049
Certificates of deposit
Assets
Investments	1,305	20,650
Fair Value, Recurring
Assets
Cash and cash equivalents	313,509	263,462
Total assets held at fair value	658,666	649,205
Liabilities
Contingent consideration		10,124
Total liabilities held at fair value		10,124
Fair Value, Recurring | U.S. Government and agency securities
Assets
Investments	104,159	67,815
Fair Value, Recurring | Obligations of government-sponsored enterprises
Assets
Investments		5,229
Fair Value, Recurring | Corporate debt securities
Assets
Investments	239,693	292,049
Fair Value, Recurring | Certificates of deposit
Assets
Investments	1,305	20,650
Fair Value, Recurring | Level 1
Assets
Total assets held at fair value	104,159	67,815
Fair Value, Recurring | Level 1 | U.S. Government and agency securities
Assets
Investments	104,159	67,815
Fair Value, Recurring | Level 2
Assets
Cash and cash equivalents	313,509	263,462
Total assets held at fair value	554,507	581,390
Fair Value, Recurring | Level 2 | Obligations of government-sponsored enterprises
Assets
Investments		5,229
Fair Value, Recurring | Level 2 | Corporate debt securities
Assets
Investments	239,693	292,049
Fair Value, Recurring | Level 2 | Certificates of deposit
Assets
Investments	$ 1,305	20,650
Fair Value, Recurring | Level 3
Liabilities
Contingent consideration		10,124
Total liabilities held at fair value		$ 10,124

Summary of Significant Accou_23

Summary of Significant Accounting Policies - Fair Value Measurements - Assets and Liabilities - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Summary of Significant Accounting Policies
Cash held in bank accounts	$ 11.7	$ 8.8

Summary of Significant Accou_24

Summary of Significant Accounting Policies - Fair Value Measurements - Transfers (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair value transfers
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$ 0	$ 0
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	$ 0	$ 0

Summary of Significant Accou_25

Summary of Significant Accounting Policies - Fair Value Measurements - Debt (Details) $ in Millions	Dec. 31, 2019USD ($)
Level 1 | Senior Notes | 4.400% Senior Notes due 2024
Debt
Fair value of debt	$ 403.4
Level 2 | Unsecured Debt | 2017 Credit Agreement, senior unsecured term loan facility
Debt
Fair value of debt	$ 280.6

Summary of Significant Accou_26

Summary of Significant Accounting Policies - Contingent Consideration - General Information (Details) $ in Thousands	Dec. 31, 2018USD ($)
Contingent consideration
Estimated undiscounted future contingent payments	$ 10,600
Fair value of short-term contingent consideration	8,000
Fair value of long-term contingent consideration	$ 2,124

Summary of Significant Accou_27

Summary of Significant Accounting Policies - Contingent Consideration - Change in Fair Value (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Contingent consideration
Changes in fair value of contingent consideration	$ (2.1)	$ 1.3	$ 0.7

Summary of Significant Accou_28

Summary of Significant Accounting Policies - Contingent Consideration - Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of beginning of period	$ 10,124	$ 8,817
Changes in fair value	$ (2,124)	$ 1,307
Fair Value, Recurring Basis, Unobservable Input Reconciliation, Liability, Gain (Loss), Statement of Income	mgln:DirectServiceCostsAndOtherOperatingExpenses	mgln:DirectServiceCostsAndOtherOperatingExpenses
Payments	$ (8,000)
Balance as of end of period	$ 0	$ 10,124

Summary of Significant Accou_29

Summary of Significant Accounting Policies - Investments - Realized Gains or Losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Realized gains or losses
Realized gains or losses	$ 0	$ 0	$ 0

Summary of Significant Accou_30

Summary of Significant Accounting Policies - Investments - Amortized Cost (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amortized cost
Amortized Cost	$ 344,965	$ 386,169
Gross Unrealized Gains	250	23
Gross Unrealized Losses	(58)	(449)
Estimated Fair Value	345,157	385,743	$ 327,865
U.S. Government and agency securities
Amortized cost
Amortized Cost	104,096	67,870
Gross Unrealized Gains	75	17
Gross Unrealized Losses	(12)	(72)
Estimated Fair Value	104,159	67,815
Obligations of government-sponsored enterprises
Amortized cost
Amortized Cost		5,257
Gross Unrealized Losses		(28)
Estimated Fair Value		5,229
Corporate debt securities
Amortized cost
Amortized Cost	239,564	292,392
Gross Unrealized Gains	175	6
Gross Unrealized Losses	(46)	(349)
Estimated Fair Value	239,693	292,049
Certificates of deposit
Amortized cost
Amortized Cost	1,305	20,650
Estimated Fair Value	$ 1,305	$ 20,650

Summary of Significant Accou_31

Summary of Significant Accounting Policies - Investments by Maturity Date (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amortized Cost
Investments amortized cost maturity dates 2020	$ 334,304
Investments amortized cost maturity dates 2021	10,661
Amortized Cost	344,965	$ 386,169
Estimated Fair Value
Investments fair value maturity dates 2020	334,489
Investments fair value maturity dates 2020	10,668
Estimated Fair Value	$ 345,157	$ 385,743	$ 327,865

Summary of Significant Accou_32

Summary of Significant Accounting Policies - Property and Equipment - Useful Lives (Details)	12 Months Ended
	Dec. 31, 2019
Building improvements | Minimum
Property and Equipment
Estimated useful lives of assets	2 years
Building improvements | Maximum
Property and Equipment
Estimated useful lives of assets	10 years
Equipment | Minimum
Property and Equipment
Estimated useful lives of assets	3 years
Equipment | Maximum
Property and Equipment
Estimated useful lives of assets	15 years
Capitalized internal-use software | Minimum
Property and Equipment
Estimated useful lives of assets	3 years
Capitalized internal-use software | Maximum
Property and Equipment
Estimated useful lives of assets	5 years

Summary of Significant Accou_33

Summary of Significant Accounting Policies - Property and Equipment - Capitalized Internal-use Software (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property and Equipment
Property and equipment, net	$ 138,422	$ 150,748
Capitalized internal-use software
Property and Equipment
Property and equipment, net	$ 69,200	$ 71,700

Summary of Significant Accou_34

Summary of Significant Accounting Policies - Property and Equipment - Depreciation expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Depreciation expense
Depreciation expense	$ 74.5	$ 80.9	$ 76.5
Capitalized internal-use software
Depreciation expense
Depreciation expense	$ 46.7	$ 50	$ 49.5

Summary of Significant Accou_35

Summary of Significant Accounting Policies - Property and Equipment - Tabular Disclosure (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property and Equipment
Property and equipment, gross	$ 845,806	$ 799,303
Accumulated depreciation	(707,384)	(648,555)
Property and equipment, net	138,422	150,748
Building improvements
Property and Equipment
Property and equipment, gross	18,546	18,954
Equipment
Property and Equipment
Property and equipment, gross	200,238	201,343
Capital leases - property
Property and Equipment
Property and equipment, gross	26,945	26,945
Capital leases - equipment
Property and Equipment
Property and equipment, gross	29,088	24,932
Capitalized internal-use software
Property and Equipment
Property and equipment, gross	570,989	527,129
Property and equipment, net	$ 69,200	$ 71,700

Summary of Significant Accou_36

Summary of Significant Accounting Policies - Goodwill - General Information (Details) - segment	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill
Number of reporting units	3	3	3
Healthcare
Goodwill
Number of reporting units	2	2	2
Pharmacy Management
Goodwill
Number of reporting units	1	1	1

Summary of Significant Accou_37

Summary of Significant Accounting Policies - Goodwill - Reporting Units (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill
Goodwill	$ 1,018,156	$ 1,018,156	$ 1,006,288
Behavioral & Specialty Health
Goodwill
Goodwill	$ 410,869	$ 410,869
Reporting Unit, Name of Segment	mgln:HealthcareSegmentMember	mgln:HealthcareSegmentMember
Magellan Complete Care
Goodwill
Goodwill	$ 211,735	$ 211,735
Reporting Unit, Name of Segment	mgln:HealthcareSegmentMember	mgln:HealthcareSegmentMember
Pharmacy Management
Goodwill
Goodwill	$ 395,552	$ 395,552
Reporting Unit, Name of Segment	mgln:PharmacyManagementMember	mgln:PharmacyManagementMember

Summary of Significant Accou_38

Summary of Significant Accounting Policies - Goodwill - Roll Forward (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Goodwill
Balance as of beginning of period	$ 1,006,288
Other acquisitions and measurement period adjustments	11,868
Balance as of end of period	$ 1,018,156

Summary of Significant Accou_39

Summary of Significant Accounting Policies - Intangible Assets - Useful Lives (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Customer agreements and lists | Minimum
Finite-Lived Intangible Assets [Line Items]
Period of amortization of intangible assets acquired	2 years 6 months	2 years 6 months
Customer agreements and lists | Maximum
Finite-Lived Intangible Assets [Line Items]
Period of amortization of intangible assets acquired	18 years	18 years
Customer agreements and lists | Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Avg, Remaining Useful Life	3 years 4 months 24 days	4 years 6 months
Provider networks and other | Minimum
Finite-Lived Intangible Assets [Line Items]
Period of amortization of intangible assets acquired	1 year	1 year
Provider networks and other | Maximum
Finite-Lived Intangible Assets [Line Items]
Period of amortization of intangible assets acquired	16 years	16 years
Provider networks and other | Weighted Average
Finite-Lived Intangible Assets [Line Items]
Weighted Avg, Remaining Useful Life	1 year 7 months 6 days	2 years 3 months 18 days

Summary of Significant Accou_40

Summary of Significant Accounting Policies - Intangible Assets - Finite-lived (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite-lived intangible assets
Accumulated Amortization	$ (334,174)	$ (284,518)
Customer agreements and lists
Finite-lived intangible assets
Gross Carrying Amount	441,346	441,346
Accumulated Amortization	(309,296)	(262,729)
Net Carrying Amount	132,050	178,617
Provider networks and other
Finite-lived intangible assets
Gross Carrying Amount	29,752	44,635
Accumulated Amortization	(24,878)	(21,789)
Net Carrying Amount	$ 4,874	$ 22,846

Summary of Significant Accou_41

Summary of Significant Accounting Policies - Intangible Assets - Indefinite-lived (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Indefinite-lived intangible assets
Trade names and licenses	$ 30,420	$ 30,420

Summary of Significant Accou_42

Summary of Significant Accounting Policies - Intangible Assets - Total (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Intangible assets
Gross Carrying Amount	$ 501,518	$ 516,401
Accumulated Amortization	(334,174)	(284,518)
Intangible Assets, Net (Excluding Goodwill), Total	$ 167,344	$ 231,883	$ 268,288

Summary of Significant Accou_43

Summary of Significant Accounting Policies - Intangible Assets - Amortization Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary of Significant Accounting Policies
Amortization expense	$ 57	$ 51.8	$ 39.2

Summary of Significant Accou_44

Summary of Significant Accounting Policies - Intangible Assets - Estimated Future Amortization Expense (Details) $ in Millions	Dec. 31, 2019USD ($)
Estimated amortization expense in future
2020	$ 56.2
2021	35.5
2022	23.8
2023	17.1
2024	$ 4

Summary of Significant Accou_45

Summary of Significant Accounting Policies - Medical Claims Payable (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cost of Care, Medical Claims Payable and Other Medical Liabilities
Period considered for comparing medical claims trend									2 months
Minimum completion factor of insured claims to make projection from historical completion and payment patterns (as a percent)									70.00%
Changes in medical claims payable
Claims payable and IBNR, beginning of period				$ 394,140				$ 326,642	$ 394,140	$ 326,642	$ 188,618
Cost of care:
Current year									3,962,831	3,772,112	2,421,270
Prior years									(22,300)	(9,700)	(7,500)
Total cost of care	$ 983,678	$ 1,013,006	$ 1,001,886	$ 941,961	$ 959,906	$ 938,031	$ 935,814	$ 928,661	3,940,531	3,762,412	2,413,770
Claim payments and transfers to other medical liabilities:
Current year									3,594,018	3,402,010	2,210,346
Prior years									332,650	292,904	161,798
Total claim payments and transfers to other medical liabilities									3,926,668	3,694,914	2,372,144
Acquisition of SWH											96,398
Claims payable and IBNR, end of period	408,003				394,140				408,003	394,140	326,642
Withhold (receivables), end of period											983
Withhold payable, end of period	1,530				(593)				1,530	(593)
Medical claims payable, end of period	$ 409,533				$ 393,547				$ 409,533	$ 393,547	$ 327,625

Summary of Significant Accou_46

Summary of Significant Accounting Policies - Leases - General Information (Details)	12 Months Ended
	Dec. 31, 2019item
Leases
Renewal terms	true
Minimum
Leases
Options to renew	1
Options to extend the lease renewal terms	1 year
Maximum
Leases
Options to extend the lease renewal terms	10 years

Summary of Significant Accou_47

Summary of Significant Accounting Policies - Leases - Lease Expenses (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Components of leases expenses:
Operating lease cost	$ 16,781
Amortization of right-of-use asset	4,038
Interest on lease liabilities	2,045
Total finance lease cost	6,083
Short-term lease cost	1,227
Variable lease cost	3,243
Total lease cost	27,334
Sublease income	(450)
Net lease cost	$ 26,884

Summary of Significant Accou_48

Summary of Significant Accounting Policies - Leases - Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Components of lease assets and liabilities
Operating lease right-of-use assets	$ 50,460	$ 59,800
Operating Lease, Right-of-Use Asset, Statement of Financial Position	us-gaap:OtherAssetsNoncurrent
Current operating lease liabilities	$ 13,211
Operating Lease, Liability, Current, Statement of Financial Position	us-gaap:AccruedLiabilitiesCurrent
Long-term operating lease liabilities	$ 45,417
Operating Lease, Liability, Noncurrent, Statement of Financial Position	us-gaap:DeferredCreditsAndOtherLiabilitiesNoncurrent
Total operating lease liabilities	$ 58,628
Operating Lease, Liability, Statement of Financial Position	us-gaap:AccruedLiabilitiesCurrent us-gaap:DeferredCreditsAndOtherLiabilitiesNoncurrent
Finance lease assets	$ 13,064
Finance Lease, Right-of-Use Asset, Statement of Financial Position	us-gaap:PropertyPlantAndEquipmentNet
Current finance lease liabilities	$ 4,198
Finance Lease, Liability, Current, Statement of Financial Position	us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent
Long-term finance lease liabilities	$ 13,878
Finance Lease, Liability, Noncurrent, Statement of Financial Position	us-gaap:LongTermDebtAndCapitalLeaseObligations
Total finance lease liabilities	$ 18,076
Total lease liabilities	$ 76,704	$ 67,900

Summary of Significant Accou_49

Summary of Significant Accounting Policies - Leases - Maturity Dates (Details) $ in Thousands	Dec. 31, 2019USD ($)
Leases
2020	$ 17,892
2021	17,319
2022	16,298
2023	12,139
2024	10,302
2025 and beyond	4,658
Total lease payments	$ 78,608

Summary of Significant Accou_50

Summary of Significant Accounting Policies - Leases - Gross Difference (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Leases
Total lease payments	$ 78,608
Less interest	(1,904)
Present value of lease liabilities	$ 76,704	$ 67,900

Summary of Significant Accou_51

Summary of Significant Accounting Policies - Leases - Weighted Average Remaining Lease Term and Discount Rate (Details)	Dec. 31, 2019
Leases
Weighted average remaining lease term, operating leases	4 years 5 months 8 days
Weighted average remaining lease term, finance leases	4 years 9 months
Weighted average discount rate, operating leases	4.79%
Weighted average discount rate, finance leases	4.52%

Summary of Significant Accou_52

Summary of Significant Accounting Policies - Leases - Supplemental Cash Flow Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Leases
Operating cash flows from operating leases	$ 17,422
Operating cash flows from finance leases	4,197
Financing cash flows from finance leases	812
Right-of-use asset obtained in exchange for new lease obligation, operating leases	$ 5,831

Summary of Significant Accou_53

Summary of Significant Accounting Policies - Accrued Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accrued Liabilities
Accrued customer settlement liabilities	$ 87.5	$ 93.8
Accounts payable rebates	$ 51

Summary of Significant Accou_54

Summary of Significant Accounting Policies - Stock Compensation - Stock Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Compensation
Stock compensation expense	$ 25.5	$ 29.5	$ 39.1
Minimum
Stock Compensation
Estimated forfeitures (as a percent)	0.00%	0.00%	0.00%
Maximum
Stock Compensation
Estimated forfeitures (as a percent)	4.00%	4.00%	4.00%

Summary of Significant Accou_55

Summary of Significant Accounting Policies - Stock Compensation - Vesting Periods (Details)	12 Months Ended
	Dec. 31, 2019
Stock options
Stock Compensation
Vesting period	3 years
Restricted Stock Units (RSUs)
Stock Compensation
Vesting period	3 years
Performance Based Restricted Stock Units ("PSUs")
Stock Compensation
Vesting period	3 years

Acquisitions (Details)

Acquisitions (Details) - SWH $ in Millions	Oct. 31, 2017USD ($)
Acquisitions
Base purchase price	$ 400.4
Working capital adjustments	0.4
Contingent payment included in purchase consideration	$ 10

Benefit Plans (Details)

Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
401(k) Plan
Maximum contribution to defined contribution retirement plan by employee, as a percentage of compensation	75.00%
Employer's matching contribution as a percentage of employee's contribution	50.00%
Maximum employer matching contribution to defined contribution retirement plan, as a percentage of compensation	6.00%
Expense recognized	$ 15.2	$ 14.9	$ 12.7

Long-Term Debt, Finance Lease a

Long-Term Debt, Finance Lease and Deferred Financing Obligations - Senior Notes (Details) - Senior Notes - 4.400% Senior Notes due 2024 - USD ($) $ in Millions	Sep. 22, 2017	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Debt
Debt instrument, face amount	$ 400
Stated interest rate (as a percent)	4.40%
Debt instrument, repurchased face amount		$ 11.1	$ 11.1
Gain (loss) on repurchase of debt instrument		(0.3)
Long-term debt		$ 388.4	$ 388.4	$ 399.4
Debt instrument, maturity date			Sep. 22, 2024
Redemption price of the principal amount redeemed (as a percent)	100.00%

Long-Term Debt, Finance Lease_2

Long-Term Debt, Finance Lease and Deferred Financing Obligations - Credit Agreement - General Information (Details) - Unsecured Debt - USD ($) $ in Millions	Aug. 13, 2018	Aug. 12, 2018	Sep. 22, 2017	Dec. 31, 2019
2017 Credit Agreement
Debt
Debt instrument, maturity date	Sep. 22, 2023	Sep. 22, 2022	Sep. 22, 2022	Sep. 22, 2023
2017 Credit Agreement | Federal Funds Rate
Debt
Basis spread on variable rate (as a percent)			0.50%
2017 Credit Agreement, senior unsecured revolving credit facility
Debt
Maximum borrowing capacity			$ 400
Commitment commission (as a percent)				0.20%
Weighted average interest rate (as a percent)				4.1261%
2017 Credit Agreement, senior unsecured revolving credit facility | Prime rate
Debt
Basis spread on variable rate (as a percent)			0.50%
2017 Credit Agreement, senior unsecured revolving credit facility | Eurodollar rate for one month
Debt
Basis spread on variable rate (as a percent)			1.00%
2017 Credit Agreement, senior unsecured revolving credit facility | Eurodollar rate for selected interest period
Debt
Basis spread on variable rate (as a percent)			1.50%
2017 Credit Agreement, senior unsecured term loan facility
Debt
Maximum borrowing capacity			$ 350

Long-Term Debt, Finance Lease_3

Long-Term Debt, Finance Lease and Deferred Financing Obligations - Credit Agreement - Contractual Maturities (Details) - Unsecured Debt - 2017 Credit Agreement, senior unsecured term loan facility $ in Millions	Dec. 31, 2019USD ($)
Long-term Debt, Fiscal Year Maturity
2020	$ 0
2021	5
2022	17.5
2023	$ 258.1

Long-Term Debt, Finance Lease_4

Long-Term Debt, Finance Lease and Deferred Financing Obligations - Credit Agreement - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt
Deferred loan issuance cost	$ 5.7	$ 5.9
Unsecured Debt | 2017 Credit Agreement, senior unsecured revolving credit facility
Debt
Revolving borrowings outstanding	0
Available borrowing capacity	$ 400

Long-Term Debt, Finance Lease_5

Long-Term Debt, Finance Lease and Deferred Financing Obligations - Letter of Credit Agreement (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Long Term Debt, Capital Lease and Deferred Financing Obligations
Letters of credit outstanding	$ 66.4	$ 66.1

Long-Term Debt, Finance Lease_6

Long-Term Debt, Finance Lease and Deferred Financing Obligations - Finance Lease (Details) $ in Thousands	Dec. 31, 2019USD ($)
Leases
Finance lease liability	$ 18,076
Gross cost of finance leased assets	$ 56,000

Long-Term Debt, Finance Lease_7

Long-Term Debt, Finance Lease and Deferred Financing Obligations - Deferred Financing Obligations (Details) $ in Millions	Dec. 31, 2018USD ($)
Capital Lease Obligations
Capital lease obligations	$ 31.2
Gross Cost of Finance Lease Assets
Gross cost of finance leased assets	$ 51.9

Stockholders' Equity - Stock Co

Stockholders' Equity - Stock Compensation - Management Incentive Plan (Details)	May 18, 2016multipliershares	Dec. 31, 2019shares
Stock options
Stock Compensation
Vesting period		3 years
Life of options (expiration period)		10 years
Restricted Stock Units (RSUs)
Stock Compensation
Vesting period		3 years
Performance Based Restricted Stock Units ("PSUs")
Stock Compensation
Vesting period		3 years
2016 Management Incentive Plan
Stock Compensation
Maximum number of shares available (in shares)	4,000,000
Multiplier for delivery of shares under full-value awards | multiplier	1.60
Number of shares available for grant		2,599,420

Stockholders' Equity - Stock _2

Stockholders' Equity - Stock Compensation - Employee Stock Purchase Plan (Details) - shares	May 24, 2018	Dec. 31, 2019	Dec. 31, 2018	May 21, 2014
Stock Compensation
Number of shares of common stock issued under purchase plans		93,632	63,471
Employee Stock
Stock Compensation
Maximum number of shares available (in shares)				200,000
Number of additional shares issued	300,000
Number of shares available for grant		215,084

Stockholders' Equity - Stock _3

Stockholders' Equity - Stock Compensation - Options - Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Options
Outstanding, beginning of period (in shares)	2,352,609	2,458,237	2,843,177
Granted (in shares)	429,124	477,956	525,596
Forfeited (in shares)	(112,120)	(174,376)	(79,350)
Exercised (in shares)	(543,752)	(409,208)	(831,186)
Outstanding, end of period (in shares)	2,125,861	2,352,609	2,458,237
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 68.10	$ 61.50	$ 57.42
Granted (in dollars per share)	66.22	96.39	71.35
Forfeited (in dollars per share)	78.18	80.21	61.39
Exercised (in dollars per share)	60.16	56.36	53.79
Outstanding, end of period (in dollars per share)	$ 69.22	$ 68.10	$ 61.50
Vested and Expected to Vest
Vested and expected to vest end of period (in shares)	2,116,787
Vested and expected to vest end of period (in dollars per share)	$ 69.20
Exercisable, end of period (in shares)	1,607,321
Exercisable, end of period (in dollars per share)	$ 67.18
Weighted average remaining contractual term
Outstanding	5 years 1 month 17 days
Vested and expected to vest	5 years 1 month 13 days
Exercisable	3 years 11 months 26 days
Aggregate intrinsic value
Outstanding	$ 26,773
Vested and expected to vest end of period	26,689
Exercisable, end of period	$ 22,470

Stockholders' Equity - Stock _4

Stockholders' Equity - Stock Compensation - Options - General Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Compensation
Share price (in dollars per share)	$ 77.87
Total pre-tax intrinsic value of options exercised	$ 5.6	$ 17.3	$ 23.8

Stockholders' Equity - Stock _5

Stockholders' Equity - Stock Compensation - Options - Fair Value Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Assumptions
Grants in period, weighted average grant date fair value (in dollars per share)	$ 20.64	$ 25.34	$ 17.64
Stock options
Fair Value Assumptions
Risk-free interest rate (as a percent)	2.50%	2.54%	1.79%
Expected life	4 years	4 years	4 years
Expected volatility (as a percent)	35.56%	28.20%	27.75%
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%

Stockholders' Equity - Stock _6

Stockholders' Equity - Stock Compensation - Options - Unrecognized Stock Compensation Expense (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Stock Compensation
Unrecognized compensation expense, options	$ 6.8
Aggregate fair value of options vested	$ 12.8
Stock options
Stock Compensation
Unrecognized compensation expense, period of recognition	1 year 9 months 18 days

Stockholders' Equity - Stock _7

Stockholders' Equity - Stock Compensation - Options - Net Tax Benefits (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock Compensation
Provision (benefit) for income taxes	$ 8,902	$ 7,868	$ 7,606	$ 539	$ 448	$ 13,816	$ 4,824	$ (75)	$ 24,915	$ 19,013	$ 25,083
Stock options
Stock Compensation
Provision (benefit) for income taxes									1,500	$ (5,100)	(5,600)
Excess tax benefits of tax deductions in recognized stock compensation expenses									(1,800)		5,700
Deficiency of tax deductions in recognized stock compensation expenses									$ (300)		$ 100

Stockholders' Equity - Stock _8

Stockholders' Equity - Stock Compensation - Nonvested - Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restricted Stock Awards
Shares
Outstanding, beginning of period (in shares)	11,795	31,102	615,472
Awarded (in shares)	41,905	11,795	14,959
Vested (in shares)	(13,939)	(31,102)	(585,438)
Forfeited (in shares)			(13,891)
Outstanding, end of period (in shares)	39,761	11,795	31,102
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share)	$ 89.05	$ 68	$ 58.71
Awarded (in dollars per share)	65.60	89.05	70.20
Vested (in dollars per share)	85.99	68	58.33
Forfeited (in dollars per share)			65.97
Outstanding, end of period (in dollars per share)	$ 65.40	$ 89.05	$ 68
Restricted Stock Units (RSUs)
Shares
Outstanding, beginning of period (in shares)	156,750	163,289	200,178
Awarded (in shares)	212,065	111,033	107,417
Vested (in shares)	(68,993)	(84,627)	(119,489)
Forfeited (in shares)	(43,392)	(32,945)	(24,817)
Outstanding, end of period (in shares)	256,430	156,750	163,289
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share)	$ 86.68	$ 66.46	$ 61.65
Awarded (in dollars per share)	67.92	99.29	68.53
Vested (in dollars per share)	81.95	65.20	60.38
Forfeited (in dollars per share)	76.71	84.17	65.87
Outstanding, end of period (in dollars per share)	$ 74.12	$ 86.68	$ 66.46
Performance Based Restricted Stock Units ("PSUs")
Shares
Outstanding, beginning of period (in shares)	209,019	202,315	102,977
Awarded (in shares)	101,498	80,502	101,989
Vested (in shares)	(43,109)	(33,592)
Forfeited (in shares)	(18,849)	(40,206)	(2,651)
Outstanding, end of period (in shares)	248,559	209,019	202,315
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share)	$ 103.38	$ 84.63	$ 93.03
Awarded (in dollars per share)	101.82	141.61	76.24
Vested (in dollars per share)	97.12	85
Forfeited (in dollars per share)	97.49	100.96	87.75
Outstanding, end of period (in dollars per share)	$ 104.27	$ 103.38	$ 84.63

Stockholders' Equity - Stock _9

Stockholders' Equity - Stock Compensation - Nonvested - Unrecognized Stock Compensation Expense (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Restricted Stock Awards
Stock Compensation
Unrecognized compensation expense, nonvested	$ 1.5
Unrecognized compensation expense, period of recognition	7 months 2 days
Restricted Stock Units (RSUs)
Stock Compensation
Unrecognized compensation expense, nonvested	$ 12.6
Unrecognized compensation expense, period of recognition	2 years 3 days
Performance Based Restricted Stock Units ("PSUs")
Stock Compensation
Unrecognized compensation expense, nonvested	$ 7.1
Unrecognized compensation expense, period of recognition	2 years 25 days

Stockholders' Equity - Stock_10

Stockholders' Equity - Stock Compensation - Performance-Based Restricted Stock Units - General Information (Details) - Performance Based Restricted Stock Units ("PSUs")	12 Months Ended
	Dec. 31, 2019D
Stock options, Non vested restricted stock awards and nonvested restricted stock units
Term of performance period	3 years
Number of trading days considered for average share value	30
Minimum
Stock options, Non vested restricted stock awards and nonvested restricted stock units
Shares to be settled (as a percent)	0.00%
Maximum
Stock options, Non vested restricted stock awards and nonvested restricted stock units
Shares to be settled (as a percent)	200.00%

Stockholders' Equity - Stock_11

Stockholders' Equity - Stock Compensation - Performance-Based Restricted Stock Units - Fair Value Assumptions (Details) - Performance Based Restricted Stock Units ("PSUs") - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Assumptions
Weighted average estimated fair value of the PSUs granted (in dollars per share)	$ 101.82	$ 141.61	$ 76.24
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%
Risk-free interest rate (as a percent)	2.35%	2.37%	1.54%
Expected volatility, minimum (as a percent)	58.00%	20.00%	18.00%
Expected volatility, maximum (as a percent)	82.00%	82.00%	61.00%
Arithmetic Average
Fair Value Assumptions
Expected volatility (as a percent)	78.00%	35.00%	33.00%

Stockholders' Equity - Net Inco

Stockholders' Equity - Net Income Per Common Share Attributable to Magellan - Tabular Disclosure (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net income	$ 20,584	$ 21,274	$ 13,613	$ 431					$ 55,902	$ 24,181	$ 110,207
Denominator:
Weighted average number of common shares outstanding-basic	24,491	24,426	24,101	23,946	24,048	24,433	24,569	24,349	24,243	24,349	23,333
Common stock equivalents-stock options (in shares)									142	493	530
Common stock equivalents-RSAs (in shares)									8	15	376
Common stock equivalents-RSUs (in shares)									35	37	64
Common stock equivalents-PSUs (in shares)									131	137	134
Common stock equivalents-employee stock purchase plan (in shares)									4	4	3
Weighted average number of common shares outstanding-diluted (in shares)	24,905	24,708	24,416	24,213	24,048	24,928	25,407	25,612	24,563	25,035	24,440
Net income per common share-basic (in dollars per share)	$ 0.84	$ 0.87	$ 0.56	$ 0.02	$ (1.16)	$ 1.11	$ 0.55	$ 0.47	$ 2.31	$ 0.99	$ 4.72
Net income per common share-diluted (in dollars per share)	$ 0.83	$ 0.86	$ 0.56	$ 0.02	$ (1.16)	$ 1.09	$ 0.53	$ 0.45	$ 2.28	$ 0.97	$ 4.51

Stockholders' Equity - Net In_2

Stockholders' Equity - Net Income Per Common Share Attributable to Magellan - Antidilutive Securities (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stockholders' Equity
Potential dilutive securities excluded from computation of dilutive securities (in shares)	1	0.5	0.4

Stockholders' Equity - Stock Re

Stockholders' Equity - Stock Repurchases - General Information (Details) - USD ($) $ in Millions	May 24, 2018	Dec. 31, 2019	Oct. 26, 2015
Stockholders' Equity
Amount authorized under stock repurchase plan	$ 400		$ 200
Increase in amount authorized under stock repurchase plan	$ 200
Remaining authorized repurchase amount		$ 186.3

Stockholders' Equity - Stock_12

Stockholders' Equity - Stock Repurchases - Tabular Disclosure (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended				51 Months Ended
	Dec. 31, 2015	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2019
Stockholders' Equity
Share repurchases made in open market (in shares)	345,044	60,901	844,872	280,140	1,828,183	3,359,140
Average Price Paid per Share (in dollars per share)	$ 53.46	$ 61.15	$ 74.59	$ 77.67	$ 58.40
Aggregate Cost	$ 18.4	$ 3.7	$ 63	$ 21.8	$ 106.8	$ 213.7

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income taxes currently payable:
Federal									$ 13,144	$ 13,593	$ 49,944
State									4,719	7,145	6,120
Aggregate income taxes currently payable									17,863	20,738	56,064
Deferred income taxes (benefits):
Federal									6,061	307	(31,941)
State									991	(2,032)	960
Aggregate deferred income taxes									7,052	(1,725)	(30,981)
Total income tax expense	$ 8,902	$ 7,868	$ 7,606	$ 539	$ 448	$ 13,816	$ 4,824	$ (75)	$ 24,915	$ 19,013	$ 25,083

Income Taxes - Reconciliation (

Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Differences between total income tax expense and amount computed using the statutory federal income tax rate
Income tax expense at federal statutory rate									$ 16,972	$ 9,071	$ 47,328
State income taxes, net of federal income tax benefit									4,761	2,968	4,993
State contingencies added									1,178	3,644	2,161
Tax contingencies reversed due to statute closings									(3,115)	(2,651)	(2,044)
Change in valuation allowances									584	(691)	(14,973)
Adjustments for Tax Act										335	(8,677)
Share-based compensation									1,737	(4,750)	(4,724)
Qualified research credit									(1,594)	(1,781)	(1,325)
Non-deductible executive compensation									3,153	3,052	104
Non-deductible HIF fees										8,246
Other-net									1,239	1,570	2,240
Total income tax expense	$ 8,902	$ 7,868	$ 7,606	$ 539	$ 448	$ 13,816	$ 4,824	$ (75)	$ 24,915	$ 19,013	$ 25,083

Income Taxes - Statutory Rate (

Income Taxes - Statutory Rate (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes
Statutory federal income tax rate (as a percent)	21.00%	21.00%	35.00%

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carryforwards	$ 8,417	$ 11,159
Share-based compensation	9,167	10,299
Other accrued compensation	10,697	5,508
Claims reserves	5,355	7,053
Deferred revenue	4,122	4,368
Other non-deductible accrued liabilities	3,267	6,057
Indirect tax benefits	3,011	3,296
Operating lease - right-of-use liabilities	18,632
Other deferred tax assets	111	2,130
Total deferred tax assets	62,779	49,870
Valuation allowances	(2,105)	(1,521)
Deferred tax assets after valuation allowances	60,674	48,349
Deferred tax liabilities:
Depreciation	(20,577)	(21,350)
Amortization of goodwill and intangible assets	(33,073)	(30,463)
Operating lease - right-of-use assets	(16,656)
Other deferred tax liabilities	(5,562)	(4,292)
Total deferred tax liabilities	(75,868)	(56,105)
Net deferred tax liabilities	$ (15,194)	$ (7,756)

Income Taxes - Net Operating Lo

Income Taxes - Net Operating Loss Carryforwards (Details) $ in Millions	Dec. 31, 2019USD ($)
Federal
Operating loss carryforwards
Operating Loss Carryforwards	$ 16.2
State
Operating loss carryforwards
Operating Loss Carryforwards	$ 88.6

Income Taxes - Valuation Allowa

Income Taxes - Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Deferred Tax Assets, Valuation Allowance	$ 2,105	$ 1,521
Increase (decrease) in valuation allowance	$ 600

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of the beginning and ending amount of gross unrecognized tax benefits
Balance as of beginning of period	$ 15,683	$ 13,580	$ 13,604
Additions for current year tax positions	1,492	4,955	3,243
Additions for tax positions of prior years	699	512	342
Reductions for tax positions of prior years	(472)	(398)	(114)
Reductions due to lapses of applicable statutes of limitations	(3,489)	(3,005)	(2,693)
Changes due to Tax Act		339	(509)
Reductions due to settlements with taxing authorities	(43)	(300)	(293)
Balance as of end of period	$ 13,870	$ 15,683	$ 13,580

Income Taxes - Unrecognized T_2

Income Taxes - Unrecognized Tax Benefits - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Income Taxes
Unrecognized tax benefits realized that would have reduced income tax expense	$ 10.9	$ 12.3

Income Taxes - Income Tax Conti

Income Taxes - Income Tax Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income tax contingency disclosures
Unrecognized tax benefits: Changes due to lapses of statutes of limitations	$ 3,489	$ 3,005	$ 2,693
Accrued interest and penalties related to unrecognized tax benefits	700	600
Interest and penalties recorded	100	100	200
Unrecognized tax benefits, could be reversed in following year	3,400
Deferred tax assets
Income tax contingency disclosures
Unrecognized tax benefits, could be reversed in following year	700
Income Tax Expense
Income tax contingency disclosures
Unrecognized tax benefits, could be reversed in following year	2,700
Tax Year 2015
Income tax contingency disclosures
Unrecognized tax benefits: Changes due to lapses of statutes of limitations	3,500
Accrued interest reversed	300
Tax Year 2015 | Deferred tax assets
Income tax contingency disclosures
Unrecognized tax benefits: Changes due to lapses of statutes of limitations	700
Tax Year 2015 | Income Tax Expense
Income tax contingency disclosures
Unrecognized tax benefits: Changes due to lapses of statutes of limitations	$ 2,800
Tax Year 2014
Income tax contingency disclosures
Unrecognized tax benefits: Changes due to lapses of statutes of limitations		3,000
Accrued interest reversed		200
Tax Year 2014 | Deferred tax assets
Income tax contingency disclosures
Unrecognized tax benefits: Changes due to lapses of statutes of limitations		600
Tax Year 2014 | Income Tax Expense
Income tax contingency disclosures
Unrecognized tax benefits: Changes due to lapses of statutes of limitations		$ 2,400
Tax Year 2013
Income tax contingency disclosures
Unrecognized tax benefits: Changes due to lapses of statutes of limitations			3,000
Accrued interest reversed			200
Tax Year 2013 | Deferred tax assets
Income tax contingency disclosures
Unrecognized tax benefits: Changes due to lapses of statutes of limitations			1,000
Tax Year 2013 | Income Tax Expense
Income tax contingency disclosures
Unrecognized tax benefits: Changes due to lapses of statutes of limitations			$ 2,000

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Information
Income taxes paid, net of refunds	$ 4,774	$ 40,179	$ 59,474
Interest paid	29,892	34,223	15,415
Assets acquired through capital leases and deferred financing	$ 3,302	$ 20,576	$ 2,418

Commitments and Contingencies -

Commitments and Contingencies - Insurance (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Insurance
Period for which insurance policies have been renewed	1 year
Specialty pharmaceutical dispensing operations
Insurance
Period for which insurance policies have been renewed	1 year
Per claim self-insured retention	$ 50
Aggregated self-insured retention	250
General liability
Insurance
Per claim un-aggregated self-insured retention	250
Managed care liability
Insurance
Per claim un-aggregated self-insured retention	1,000
Per class action claim un-aggregated self-insured retention	10,000
Professional liability
Insurance
Per claim un-aggregated self-insured retention	$ 250

Commitments and Contingencies_2

Commitments and Contingencies - Regulatory Issues (Details)	12 Months Ended
	Dec. 31, 2018
AFSC
Acquisitions
Percentage of total revenues attributable to subsidiary	2.00%

Business Segment Information -

Business Segment Information - Operating Results by Business Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating results by business segment
Net revenue	$ 1,802,657	$ 1,828,941	$ 1,788,336	$ 1,739,489	$ 1,844,645	$ 1,853,506	$ 1,810,923	$ 1,805,077	$ 7,159,423	$ 7,314,151	$ 5,838,583
Cost of care	(983,678)	(1,013,006)	(1,001,886)	(941,961)	(959,906)	(938,031)	(935,814)	(928,661)	(3,940,531)	(3,762,412)	(2,413,770)
Cost of goods sold	(465,614)	(482,277)	(461,187)	(489,793)	(593,793)	(571,145)	(558,419)	(559,665)	(1,898,871)	(2,283,022)	(2,211,910)
Direct service costs and other	(286,051)	(266,322)	(266,434)	(271,924)	(277,835)	(265,471)	(259,152)	(269,077)	(1,090,731)	(1,071,535)	(941,883)
Stock compensation expense									25,501	29,472	39,116
Changes in fair value of contingent consideration									(2,124)	1,307	696
Less: non-controlling interest segment profit (loss)											(59)
Segment profit (loss)									252,667	227,961	310,891
Managed care and other
Operating results by business segment
Net revenue	1,292,335	1,303,936	1,283,143	1,223,979	1,207,552	1,235,787	1,215,340	1,219,763	5,103,393	4,878,442	3,479,182
PBM
Operating results by business segment
Net revenue	$ 510,322	$ 525,005	$ 505,193	$ 515,510	$ 637,093	$ 617,719	$ 595,583	$ 585,314	2,056,030	2,435,709	2,359,401
Healthcare
Operating results by business segment
Net revenue									4,838,546	4,638,622
Pharmacy Management
Operating results by business segment
Net revenue									2,502,268	2,865,844
Operating Segments | Healthcare
Operating results by business segment
Cost of care									(3,940,531)	(3,762,412)	(2,413,770)
Direct service costs and other									(726,937)	(735,366)	(601,201)
Stock compensation expense									8,467	6,982	10,689
Changes in fair value of contingent consideration									(2,124)	1,307	696
Less: non-controlling interest segment profit (loss)											(56)
Segment profit (loss)									177,421	149,133	202,747
Operating Segments | Healthcare | Managed care and other
Operating results by business segment
Net revenue									4,838,546	4,638,622	3,206,277
Operating Segments | Pharmacy Management
Operating results by business segment
Cost of goods sold									(2,076,509)	(2,468,170)	(2,341,979)
Direct service costs and other									(323,162)	(298,713)	(302,525)
Stock compensation expense									7,834	5,458	19,881
Segment profit (loss)									110,431	104,419	139,910
Operating Segments | Pharmacy Management | Managed care and other
Operating results by business segment
Net revenue									265,439	240,427	273,489
Operating Segments | Pharmacy Management | PBM
Operating results by business segment
Net revenue									2,236,829	2,625,417	2,491,044
Corporate and Eliminations
Operating results by business segment
Cost of goods sold									177,638	185,148	130,069
Direct service costs and other									(40,632)	(37,456)	(38,157)
Stock compensation expense									9,200	17,032	8,546
Less: non-controlling interest segment profit (loss)											(3)
Segment profit (loss)									(35,185)	(25,591)	(31,766)
Corporate and Eliminations | Managed care and other
Operating results by business segment
Net revenue									(592)	(607)	(584)
Corporate and Eliminations | PBM
Operating results by business segment
Net revenue									$ (180,799)	$ (189,708)	$ (131,643)

Business Segment Information _2

Business Segment Information - Identifiable Assets by Business Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment reporting information
Restricted cash	$ 146,455	$ 160,967	$ 229,013
Accounts receivable, net	890,065	756,059	660,775
Investments	345,157	385,743	327,865
Pharmaceutical inventory	44,962	40,818	40,945
Goodwill	1,018,156	1,018,156	1,006,288
Other intangible assets, net	167,344	231,883	268,288
Operating Segments | Healthcare
Segment reporting information
Restricted cash	144,229	157,437	220,786
Accounts receivable, net	410,958	290,564	244,486
Investments	338,439	378,706	327,865
Goodwill	622,604	622,604	610,867
Other intangible assets, net	105,728	136,644	165,159
Operating Segments | Pharmacy Management
Segment reporting information
Restricted cash	2,226	576	8,059
Accounts receivable, net	478,627	465,345	403,880
Investments	6,718	7,037
Pharmaceutical inventory	44,962	40,818	40,945
Goodwill	395,552	395,552	395,421
Other intangible assets, net	61,536	82,072	103,129
Corporate and Eliminations
Segment reporting information
Restricted cash		2,954	168
Accounts receivable, net	480	150	$ 12,409
Other intangible assets, net	$ 80	$ 13,167

Business Segment Information _3

Business Segment Information - Reconciliation of Segment Profit to Income Before Taxes (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of segment profit to income before income taxes
Income before income taxes	$ 29,486	$ 29,142	$ 21,219	$ 970	$ (27,519)	$ 40,961	$ 18,375	$ 11,377	$ 80,817	$ 43,194	$ 135,224
Stock compensation expense	5,669	4,811	5,414	9,607	2,067	9,320	10,439	7,646	25,501	29,472	39,116
Changes in fair value of contingent consideration	(123)	4	(2,149)	144	856	148	70	233	(2,124)	1,307	696
Non-controlling interest segment (profit) loss											59
Depreciation and amortization	33,154	34,157	33,490	30,708	35,358	33,047	33,848	30,407	131,509	132,660	115,706
Interest expense	8,898	9,007	9,141	9,107	9,362	8,990	8,678	8,366	36,153	35,396	25,977
Interest and other income	$ (4,224)	$ (4,970)	$ (5,021)	$ (4,974)	$ (4,090)	$ (4,139)	$ (3,363)	$ (2,476)	(19,189)	(14,068)	(5,887)
Segment profit (loss)									$ 252,667	$ 227,961	$ 310,891

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net revenue:
Net revenue	$ 1,802,657	$ 1,828,941	$ 1,788,336	$ 1,739,489	$ 1,844,645	$ 1,853,506	$ 1,810,923	$ 1,805,077	$ 7,159,423	$ 7,314,151	$ 5,838,583
Costs and expenses:
Cost of care	983,678	1,013,006	1,001,886	941,961	959,906	938,031	935,814	928,661	3,940,531	3,762,412	2,413,770
Cost of goods sold	465,614	482,277	461,187	489,793	593,793	571,145	558,419	559,665	1,898,871	2,283,022	2,211,910
Direct service costs and other operating expenses	286,051	266,322	266,434	271,924	277,835	265,471	259,152	269,077	1,090,731	1,071,535	941,883
Depreciation and amortization	33,154	34,157	33,490	30,708	35,358	33,047	33,848	30,407	131,509	132,660	115,706
Interest expense	8,898	9,007	9,141	9,107	9,362	8,990	8,678	8,366	36,153	35,396	25,977
Interest and other income	(4,224)	(4,970)	(5,021)	(4,974)	(4,090)	(4,139)	(3,363)	(2,476)	(19,189)	(14,068)	(5,887)
Total costs and expenses	1,773,171	1,799,799	1,767,117	1,738,519	1,872,164	1,812,545	1,792,548	1,793,700	7,078,606	7,270,957	5,703,359
Income before income taxes	29,486	29,142	21,219	970	(27,519)	40,961	18,375	11,377	80,817	43,194	135,224
Provision (benefit) for income taxes	8,902	7,868	7,606	539	448	13,816	4,824	(75)	24,915	19,013	25,083
Net income					$ (27,967)	$ 27,145	$ 13,551	$ 11,452	55,902	24,181	110,141
Less: net income (loss) attributable to non-controlling interest											(66)
Net income attributable to Magellan	$ 20,584	$ 21,274	$ 13,613	$ 431					$ 55,902	$ 24,181	$ 110,207
Weighted average number of common shares outstanding-basic	24,491	24,426	24,101	23,946	24,048	24,433	24,569	24,349	24,243	24,349	23,333
Weighted average number of common shares outstanding-diluted	24,905	24,708	24,416	24,213	24,048	24,928	25,407	25,612	24,563	25,035	24,440
Net income per common share-basic (in dollars per share)	$ 0.84	$ 0.87	$ 0.56	$ 0.02	$ (1.16)	$ 1.11	$ 0.55	$ 0.47	$ 2.31	$ 0.99	$ 4.72
Net income per common share-diluted (in dollars per share)	$ 0.83	$ 0.86	$ 0.56	$ 0.02	$ (1.16)	$ 1.09	$ 0.53	$ 0.45	$ 2.28	$ 0.97	$ 4.51
Stock compensation expense	$ 5,669	$ 4,811	$ 5,414	$ 9,607	$ 2,067	$ 9,320	$ 10,439	$ 7,646	$ 25,501	$ 29,472	$ 39,116
Changes in fair value of contingent consideration	(123)	4	(2,149)	144	856	148	70	233	(2,124)	1,307	696
Managed care and other
Net revenue:
Net revenue	1,292,335	1,303,936	1,283,143	1,223,979	1,207,552	1,235,787	1,215,340	1,219,763	5,103,393	4,878,442	3,479,182
PBM
Net revenue:
Net revenue	$ 510,322	$ 525,005	$ 505,193	$ 515,510	$ 637,093	$ 617,719	$ 595,583	$ 585,314	$ 2,056,030	$ 2,435,709	$ 2,359,401

SCHEDULE I - CONDENSED FINANC_2

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Condendsed Balance Sheets - Tabular Disclosure (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017
Current Assets:
Accounts receivable, net	$ 890,065		$ 756,059	$ 660,775
Other current assets	78,278		95,400
Total Current Assets	1,673,043		1,547,167
Other long-term assets	82,700	$ 84,350	24,530
Total Assets	3,092,173	3,038,927	2,979,056
Current Liabilities:
Accounts payable	88,415		72,077
Accrued liabilities	284,024	244,374	231,356
Total Current Liabilities	910,147	911,911	898,893
Deferred credits and other long-term liabilities	73,243	83,482	36,483
Total Liabilities	1,694,390	1,753,770	1,693,753
STOCKHOLDERS' EQUITY
Preferred stock, par value $.01 per share: Authorized - 10,000 shares at December 31, 2018 and December 31, 2019-Issued and outstanding-none
Common stock, par value $.01 per share: Authorized - 100,000 shares at December 31, 2018 and December 31, 2019-Issued and outstanding-53,536 and 23,935 shares at December 31, 2018, respectively, and 54,285 and 24,623 shares at December 31, 2019, respectively	543		535
Other Stockholders' Equity:
Additional paid-in capital	1,386,616		1,326,645
Retained earnings	1,475,207	1,419,305	1,419,449
Accumulated other comprehensive loss	144		(324)
Treasury stock, at cost, 29,601 and 29,662 shares at December 31, 2018 and December 31, 2019, respectively	(1,464,727)		(1,461,002)
Total Stockholders' Equity	1,397,783	1,285,159	1,285,303
Total Liabilities and Stockholders' Equity	3,092,173	$ 3,038,927	2,979,056
Parent Company
Current Assets:
Cash and cash equivalents	2		2
Accounts receivable, net	7
Due from affiliates, net	52,629		179,360
Other current assets	32		32
Total Current Assets	52,670		179,394
Other long-term assets	26,789		3,255
Investment in subsidiaries	2,016,039		1,832,258
Total Assets	2,095,498		2,014,907
Current Liabilities:
Accounts payable	200		399
Accrued liabilities	8,197		7,555
Current debt			16,400
Total Current Liabilities	8,397		24,354
Long-term debt	664,707		705,250
Deferred credits and other long-term liabilities	24,611
Total Liabilities	697,715		729,604
STOCKHOLDERS' EQUITY
Common stock, par value $.01 per share: Authorized - 100,000 shares at December 31, 2018 and December 31, 2019-Issued and outstanding-53,536 and 23,935 shares at December 31, 2018, respectively, and 54,285 and 24,623 shares at December 31, 2019, respectively	543		535
Other Stockholders' Equity:
Additional paid-in capital	1,386,616		1,326,645
Retained earnings	1,475,207		1,419,449
Accumulated other comprehensive loss	144		(324)
Treasury stock, at cost, 29,601 and 29,662 shares at December 31, 2018 and December 31, 2019, respectively	(1,464,727)		(1,461,002)
Total Stockholders' Equity	1,397,783		1,285,303
Total Liabilities and Stockholders' Equity	$ 2,095,498		$ 2,014,907

SCHEDULE I - CONDENSED FINANC_3

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Condendsed Balance Sheets - Additional Information (Details) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Preferred stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock
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)	54,285,000	53,536,000
Common stock, outstanding (in shares)	24,623,000	23,935,000
Treasury stock
Treasury stock (in shares)	29,662,000	29,601,000
Parent Company
Preferred stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	10,000	10,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	100,000	100,000
Common stock, issued (in shares)	54,285	53,536
Common stock, outstanding (in shares)	24,623	23,935
Treasury stock
Treasury stock (in shares)	29,662	29,601

SCHEDULE I - CONDENSED FINANC_4

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Condendsed Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Costs and expenses:
Direct service costs and other operating expenses	$ 286,051	$ 266,322	$ 266,434	$ 271,924	$ 277,835	$ 265,471	$ 259,152	$ 269,077	$ 1,090,731	$ 1,071,535	$ 941,883
Interest expense	8,898	9,007	9,141	9,107	9,362	8,990	8,678	8,366	36,153	35,396	25,977
Interest and other income	(4,224)	(4,970)	(5,021)	(4,974)	(4,090)	(4,139)	(3,363)	(2,476)	(19,189)	(14,068)	(5,887)
Total costs and expenses	1,773,171	1,799,799	1,767,117	1,738,519	1,872,164	1,812,545	1,792,548	1,793,700	7,078,606	7,270,957	5,703,359
Income before income taxes	29,486	29,142	21,219	970	(27,519)	40,961	18,375	11,377	80,817	43,194	135,224
Provision (benefit) for income taxes	8,902	7,868	7,606	539	$ 448	$ 13,816	$ 4,824	$ (75)	24,915	19,013	25,083
Net income attributable to Magellan	$ 20,584	$ 21,274	$ 13,613	$ 431					55,902	24,181	110,207
Other comprehensive income:
Unrealized (loss) gain on available-for-sale securities									468	56	(205)
Comprehensive income attributable to Magellan									56,370	24,237	110,002
Parent Company
Costs and expenses:
Direct service costs and other operating expenses									40,632	37,456	38,157
Interest expense									34,964	33,258	8,343
Interest and other income										(98)	(157)
Total costs and expenses									75,596	70,616	46,343
Income before income taxes									(75,596)	(70,616)	(46,343)
Provision (benefit) for income taxes									19,437	18,288	17,918
Net loss before equity in subsidiaries									(56,159)	(52,328)	(28,425)
Equity in earnings from subsidiaries									112,061	76,509	138,632
Net income attributable to Magellan									55,902	24,181	110,207
Other comprehensive income:
Unrealized (loss) gain on available-for-sale securities									468	56	(205)
Comprehensive income attributable to Magellan									$ 56,370	$ 24,237	$ 110,002

SCHEDULE I - CONDENSED FINANC_5

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Condendsed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net cash used in operating activities	$ 115,846	$ 164,844	$ 162,273
Cash flows from investing activities:
Net cash used in investing activities	(19,493)	(128,433)	(316,390)
Cash flows from financing activities:
Proceeds from issuance of debt			1,041,736
Proceeds from exercise of stock options	32,708	23,064	44,355
Payments to acquire treasury stock	(4,125)	(62,640)	(21,765)
Other	1,763	(1,020)	(9,560)
Net cash used in financing activities	(43,412)	(162,835)	248,341
Net cash provided by (used in) financing activities	52,941	(126,424)	94,224
Cash and cash equivalents at beginning of period	272,308	398,732	304,508
Cash and cash equivalents at end of period	325,249	272,308	398,732
Parent Company
Cash flows from operating activities:
Net cash used in operating activities	(51,423)	(54,394)	(21,778)
Cash flows from investing activities:
Dividends (capital contributions to)/received from subsidiaries, net	80,511	205,466	(836,396)
Net cash used in investing activities	80,511	205,466	(836,396)
Cash flows from financing activities:
Proceeds from issuance of debt			841,736
Proceeds from exercise of stock options	32,715	23,064	44,355
Payments to acquire treasury stock	(3,725)	(63,040)	(21,765)
Payments on debt	(58,567)	(110,000)	(4,375)
Other	489	(1,096)	(1,777)
Net cash used in financing activities	(29,088)	(151,072)	858,174
Cash and cash equivalents at beginning of period	2	2
Cash and cash equivalents at end of period	$ 2	$ 2	$ 2

SCHEDULE I - CONDENSED FINANC_6

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Subsidiary Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Parent Company
Subsidiary Transactions
Cash dividends	$ 61.7	$ 68	$ 34.7

SCHEDULE I - CONDENSED FINANC_7

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019
Components of lease assets and liabilities
Lease Liability	$ 76,704	$ 67,900
Leases
2020	17,892
2021	17,319
2022	16,298
2023	12,139
2024	10,302
2025 and beyond	4,658
Parent Company
Components of lease assets and liabilities
Right-of-use Asset	23,500
Lease Liability	28,400
Operating lease expense
Operating lease expense	8,500
Leases
2020	3,800
2021	4,900
2022	5,200
2023	5,300
2024	5,100
2025 and beyond	$ 4,100

SCHEDULE I - CONDENSED FINANC_8

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Long Term Debt - Maturities (Details) - Unsecured Debt - 2017 Credit Agreement, senior unsecured term loan facility $ in Millions	Dec. 31, 2019USD ($)
Long-term Debt, Fiscal Year Maturity
2020	$ 0
2021	5
2022	17.5
2023	258.1
Parent Company
Long-term Debt, Fiscal Year Maturity
2020	0
2021	5
2022	17.5
2023	$ 258.1

SCHEDULE I - CONDENSED FINANC_9

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Long Term Debt - Senior Notes (Details) - Senior Notes - 4.400% Senior Notes due 2024	Dec. 31, 2019	Sep. 22, 2017
Debt Instruments [Abstract]
Stated interest rate (as a percent)		4.40%
Parent Company
Debt Instruments [Abstract]
Stated interest rate (as a percent)	4.40%