Express Scripts Holding 10-Q 2 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Apr. 27, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Express Scripts Holding Co.
Entity Central Index Key	1,532,063
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	ESRX
Amendment Flag	false
Entity Common Stock, Shares Outstanding		561,721

Unaudited Consolidated Balance

Unaudited Consolidated Balance Sheet - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 2,317.6	$ 2,309.6
Receivables, net	6,793.6	7,056.3
Inventories	2,027.8	2,124.9
Prepaid expenses and other current assets	335.8	466.3
Total current assets	11,474.8	11,957.1
Property and equipment, net	552.9	551.3
Computer software, net	818.6	814.9
Goodwill	31,105.1	31,099.7
Other intangible assets, net	9,232.8	9,625.9
Other assets	221.4	206.9
Total assets	53,405.6	54,255.8
Current liabilities:
Claims and rebates payable	9,969.4	10,188.5
Accounts payable	3,957.4	3,755.7
Accrued expenses	2,710.7	2,869.3
Short-term debt and current maturities of long-term debt	85.6	1,032.9
Total current liabilities	16,723.1	17,846.4
Long-term debt	14,900.5	14,981.5
Deferred taxes	2,496.5	2,562.4
Other liabilities	837.4	740.2
Total liabilities	34,957.5	36,130.5
Commitments and contingencies (Note 12)
Stockholders’ equity:
Preferred stock, 15.0 shares authorized, $0.01 par value per share; no shares issued and outstanding	0	0
Common stock, 2,985.0 shares authorized, $0.01 par value; shares issued: 865.0 and 862.3, respectively; shares outstanding: 561.7 and 564.4, respectively	8.7	8.6
Additional paid-in capital	23,651.5	23,537.8
Accumulated other comprehensive loss	(5.7)	(2.9)
Retained earnings	16,941.8	16,318.6
Total Express Scripts stockholders' equity before treasury stock and non-controlling interest	40,596.3	39,862.1
Common stock in treasury at cost, 303.3 and 297.9 shares, respectively	(22,153.8)	(21,742.5)
Total Express Scripts stockholders' equity	18,442.5	18,119.6
Non-controlling interest	5.6	5.7
Total stockholders' equity	18,448.1	18,125.3
Total liabilities and stockholders' equity	$ 53,405.6	$ 54,255.8

Unaudited Consolidated Balance3

Unaudited Consolidated Balance Sheet (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred stock, shares authorized	15,000,000	15,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	2,985,000,000	2,985,000,000
Common stock, shares issued	865,000,000	862,300,000
Common stock, shares outstanding	561,700,000	564,400,000
Treasury stock, shares	303,300,000	297,900,000

Unaudited Consolidated Statemen

Unaudited Consolidated Statement of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Revenues	$ 24,769.4	$ 24,654.9
Cost of revenues	22,890	22,782.2
Gross profit	1,879.4	1,872.7
Selling, general and administrative	917.8	818.1
Operating income	961.6	1,054.6
Other (expense) income:
Interest income and other	12	6.3
Interest expense and other	(154)	(145.7)
Other (expense) income, net	(142)	(139.4)
Income before income taxes	819.6	915.2
Provision for income taxes	193.7	364.9
Net income	625.9	550.3
Less: Net income attributable to non-controlling interest	2.7	4
Net income attributable to Express Scripts	$ 623.2	$ 546.3
Weighted average number of common shares outstanding during the period:
Basic (shares)	562.8	601
Diluted (shares)	567.1	605.1
Basic earnings per share:
Earnings attributable to Express Scripts (usd per share)	$ 1.11	$ 0.91
Diluted earnings per share:
Earnings attributable to Express Scripts (usd per share)	$ 1.10	$ 0.90

Unaudited Consolidated Stateme5

Unaudited Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 625.9	$ 550.3
Other comprehensive (loss) income:
Foreign currency translation adjustment	(2.8)	1.2
Comprehensive income	623.1	551.5
Less: Comprehensive income attributable to non-controlling interests	2.7	4
Comprehensive income attributable to Express Scripts	$ 620.4	$ 547.5

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders Equity - 3 months ended Mar. 31, 2018 - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Treasury Stock	Non-controlling Interest
Balance, shares at Dec. 31, 2017		862.3
Balance at Dec. 31, 2017	$ 18,125.3	$ 8.6	$ 23,537.8	$ (2.9)	$ 16,318.6	$ (21,742.5)	$ 5.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	625.9	0	0	0	623.2	0	2.7
Other comprehensive loss	(2.8)	0	0	(2.8)	0	0	0
Treasury stock acquired	(411.3)	$ 0	0	0	0	(411.3)	0
Changes in stockholders’ equity related to employee stock plans (shares)		2.7
Changes in stockholders’ equity related to employee stock plans	113.8	$ 0.1	113.7	0	0	0	0
Distributions paid to non-controlling interest, net of contributions	(2.8)	$ 0	0	0	0	0	(2.8)
Balance, shares at Mar. 31, 2018		865
Balance at Mar. 31, 2018	$ 18,448.1	$ 8.7	$ 23,651.5	$ (5.7)	$ 16,941.8	$ (22,153.8)	$ 5.6

Unaudited Consolidated Stateme7

Unaudited Consolidated Statement of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 625.9	$ 550.3
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	498.8	445.6
Deferred income taxes	(65.6)	(53.3)
Employee stock-based compensation expense	32.3	27.1
Other, net	0.1	18.6
Changes in operating assets and liabilities, net of effects of acquisition:
Receivables	255.8	102.9
Inventories	97	203.6
Other current and noncurrent assets	129.1	29.4
Claims and rebates payable	(221.3)	(50.6)
Accounts payable	215.3	(280)
Accrued expenses	(140.2)	(10.5)
Other noncurrent liabilities	84.4	17.3
Net cash flows provided by operating activities	1,511.6	1,000.4
Cash flows from investing activities:
Capital expenditures for property and equipment and computer software	(100.4)	(45.8)
Acquisitions, net of cash acquired	(23.1)	0
Other, net	(6)	(2.3)
Net cash used in investing activities	(129.5)	(48.1)
Cash flows from financing activities:
Repayment of long-term debt	(831.4)	(37.5)
Treasury stock acquired	(420.7)	(837.4)
Commercial paper borrowings (repayments), net	(195)	0
Net proceeds from employee stock plans	82.3	14.5
Other, net	(7.2)	(6.1)
Net cash used in financing activities	(1,372)	(866.5)
Effect of foreign currency translation adjustment	(2.1)	0.8
Net increase in cash and cash equivalents	8	86.6
Cash and cash equivalents at beginning of period	2,309.6	3,077.2
Cash and cash equivalents at end of period	$ 2,317.6	$ 3,163.8

Summary of significant accounti

Summary of significant accounting policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of significant accounting policies	Note 1 - Summary of significant accounting policies Our significant accounting policies, normally included in financial statements prepared in conformity with generally accepted accounting principles, have been omitted from this Form 10-Q pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). We believe the disclosures contained in this Form 10-Q are adequate to fairly state the information when read in conjunction with the Notes to the Consolidated Financial Statements included in our consolidated financial statements for the year ended December 31, 2017 , included in Item 8 - Consolidated Financial Statements and Supplementary Data, included in our Annual Report on Form 10-K filed with the SEC on February 27, 2018 . For a description of our accounting policies, refer to the Notes to the Consolidated Financial Statements included therein. We believe the accompanying unaudited consolidated financial statements reflect all adjustments (consisting of only normal recurring adjustments) necessary to state fairly the unaudited consolidated balance sheet as of March 31, 2018 , the consolidated balance sheet as of December 31, 2017 , the unaudited consolidated statement of operations and unaudited consolidated statement of comprehensive income for the three months ended March 31, 2018 and 2017 , the unaudited consolidated statement of changes in stockholders’ equity for the three months ended March 31, 2018 , and the unaudited consolidated statement of cash flows for the three months ended March 31, 2018 and 2017 . Certain amounts in the prior year have been reclassified to conform to the current year presentation. Operating results for the three months ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 . Subsequent to December 15, 2017, the date of acquisition, our Other Business Operations segment includes medical benefit management services provided by CareCore National Group, LLC and its affiliates d/b/a eviCore healthcare (“eviCore”). See Note 5 - Acquisition for further description. Prior to December 27, 2017, our Other Business Operations segment also included consulting services for pharmaceutical and biotechnology manufacturers to collect scientific evidence to guide the safe, effective and affordable use of medicines. These services were provided by United BioSource Holdings, Inc. (“UBC”), which we sold on December 27, 2017. On March 8, 2018, we entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Cigna Corporation (“Cigna”) and certain subsidiaries of Cigna whereby Cigna will acquire Express Scripts Holding Company (“Express Scripts”) in a cash and stock transaction valued on announcement at approximately $67.0 billion , including Cigna’s assumption of approximately $15.0 billion in Express Scripts debt. The merger consideration per share of Company common stock will consist of (i) 0.2434 of a fully paid and nonassessable share of common stock of the combined company and (ii) the right to receive $48.75 in cash, without interest. Upon closing of the transaction, Cigna shareholders are expected to own approximately 64% of the combined company and Express Scripts shareholders are expected to own approximately 36% . Consummation of the merger is subject to certain customary conditions, including approval by the holders of a majority of the outstanding shares of Company common stock entitled to vote on the adoption of the Merger Agreement and approval by the holders of a majority of the outstanding shares of Cigna common stock entitled to vote on the adoption of the Merger Agreement, the shares of common stock of the combined company to be issued in the merger having been approved for listing on the New York Stock Exchange, the receipt of certain necessary governmental and regulatory approvals without the imposition of Burdensome Conditions (as defined in the Merger Agreement), the lack of pending litigation instituted by certain governmental entities to enjoin, restrain or prohibit the merger, and the receipt by each of the Company and Cigna of certain tax opinions. On April 23, 2018, Cigna and Express Scripts each received a request for additional information and documentary material from the U.S. Department of Justice (the “DOJ”) in connection with the DOJ’s review of the transaction. The merger is expected to be completed by December 31, 2018. Until the closing, we will continue to operate as an independent company. Adopted new accounting guidance. In May 2014, Financial Accounting Standards Board (“FASB”) issued ASU 2014-09, Revenue from Contracts with Customers (ASC Topic 606), which supersedes ASC Topic 605, Revenue Recognition. The new standard requires companies to recognize revenues upon transfer of goods or services to customers in amounts that reflect the consideration which the company expects to receive in exchange for those goods or services. We adopted ASC Topic 606, as of January 1, 2018, using the modified retrospective method applied to all contracts. The effect of initially applying the new revenue standard did not result in an opening balance adjustment to retained earnings as of the beginning of the earliest comparative period presented, however, it did result in an increase to both revenues and cost of revenues for the period ended March 31, 2018. The following are the impacts of the new revenue standard upon adoption: • resulted in reclassifications between revenues and cost of revenues, • provided new guidance for evaluating performance obligations, which affected how we understand the nature of our promises to customers, the control we have in PBM arrangements, and the principal-agent analysis, and resulted in changing recognition of certain contracts from net to gross, and • required non-cash consideration associated with a certain contract where the client replenishes inventory to be recognized at fair value. These changes resulted in an increase to both revenues and cost of revenues of $798.8 million for the three months ended March 31, 2018, with no impact to gross profit. In August 2016, FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230), Classification of Certain Cash Receipts and Cash Payments. The guidance addresses the classification of cash flow related to (1) debt prepayment or extinguishment costs, (2) settlement of zero-coupon debt instruments or other debt instruments with coupon rates that are insignificant in relation to the effective interest rate of the borrowing, (3) contingent consideration payments made after a business combination, (4) proceeds from the settlement of insurance claims, (5) proceeds from the settlement of corporate-owned life insurance, including bank-owned life insurance, (6) distributions received from equity method investees and (7) beneficial interests in securitization transactions. The guidance also clarifies how the predominance principle should be applied when cash receipts and cash payments have aspects of more than one class of cash flows. The guidance is effective for financial statements issued for annual reporting periods beginning after December 15, 2017 and applied retrospectively. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230), Restricted Cash. This guidance requires amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. We adopted this guidance effective January 1, 2018, retrospectively, with no significant impact on our consolidated financial statements for the three months ended March 31, 2018 and 2017 . In certain historical periods, debt extinguishment costs were reclassified from an operating activity to a financing activity as a result of adoption. New accounting guidance not yet adopted . In February 2016, FASB issued ASU 2016-02, Leases (ASC Topic 842), which supersedes ASC Topic 840, Leases. This ASU is intended to increase transparency and comparability of organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The new guidance is effective for financial statements issued for annual reporting periods beginning after December 15, 2018, and early application is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue	Note 2 - Revenue Revenues are recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. Revenue recognition - PBM. Revenues from our PBM segment are earned by dispensing prescriptions from our home delivery and specialty pharmacies, processing claims for prescriptions filled by retail pharmacies in our networks, and providing services to drug manufacturers, including administration of discount programs (see also “Rebate accounting” below). Our PBM contracts with customers generally obligate us to provide prescription drugs to the client’s members through multiple distribution methods, including retail network, home delivery, and specialty pharmacies as needed. We provide a service of integrating the goods and services selected by our clients into one overall output for which the client has contracted. Thus, PBM contracts generally contain a single performance obligation. We have elected the practical expedient to account for shipping and handling as a fulfillment activity. The nature of our performance obligation is to stand ready to process claims, dispense prescription drugs, and provide other services over the contractual period (generally three years); the quantity or timing of the service provided is in the control of our clients’ members. As such, our performance obligation forms a series of distinct periods of time over which we stand ready to perform. Our performance obligation is satisfied as we complete each period’s (day’s) obligations. Consideration from PBM contracts is variable in nature because fees are based on services provided to members and claims processed, which can vary from period to period and are outside of our control. Fees are invoiced to our clients either on a periodic basis (e.g., monthly) or as service is provided (e.g., based on volume of claims processed or other service provided) and payment terms are due within 30 days. Variable consideration in our PBM contracts meets the criteria to be allocated to the distinct period of time to which it occurs because (i) it is related to the activities performed to satisfy the performance obligation during that period and (ii) it represents the value provided to our customers over the contract term. Revenues related to dispensing prescription drugs by retail pharmacies in our networks consist of the prescription price (ingredient cost plus dispensing fee) negotiated with our clients, including the portion to be settled directly by the member (co-payment), plus any associated fees for services. The variable consideration associated with retail network transactions is recognized as revenue when claims are adjudicated. We act as a principal in the arrangement and we include the total prescription price as revenues. Through adjudication, we control the process of dispensing the drug even though physical delivery is provided by a retail network pharmacy. When a prescription is presented by a member to a retail pharmacy within our network, we are solely responsible for confirming member eligibility, performing drug utilization review, reviewing for drug-to-drug interactions, performing clinical intervention which may involve a call to the member’s physician, communicating plan provisions to the pharmacy, directing payment to the pharmacy and billing the client for the amount it is contractually obligated to pay us for the prescription dispensed, as specified within our client contracts. We also provide benefit design and formulary consultation services to clients. We have separately negotiated contractual relationships with our clients and with network pharmacies. These factors indicate we have control over the transaction before the prescription is transferred to the member and, thus, that we are acting as a principal. As such, we record the total prescription price contracted with clients in revenues. In retail pharmacy transactions, amounts paid to pharmacies and amounts charged to clients are always exclusive of the applicable co-payment. Retail pharmacy co-payments, which we instruct retail pharmacies to collect from members, are included in our revenues and our cost of revenues. When prescriptions are dispensed from our home delivery pharmacies, control of the prescription transfers and revenue is recognized when drugs are shipped. At the time of shipment, our earnings process is complete; the obligation of our customer to pay for the drugs is fixed and, due to the nature of the product, the member may not return the drugs or receive a refund. Revenues from our specialty pharmacies are from providing medications/pharmaceuticals for diseases that rely upon high-cost injectable, infused, oral or inhaled drugs which have sensitive handling and storage needs and from providing fertility pharmaceuticals to providers and patients. Control of specialty revenues earned by our PBM segment transfers to the customer at the point of shipment. At the time of shipment, we have performed substantially all of our obligations under our customer contracts and do not experience a significant level of reshipments. Appropriate reserves are recorded for discounts and contractual allowances, which represent variable consideration and are estimated based on collection experience. Any differences between our estimates and actual collections are reflected in operations in the period in which payment is received. Historically, adjustments to our original estimates have not been material. Differences may affect the amount and timing of our revenues for any period if actual performance varies from our estimates. Allowances for returns are estimated based on historical return trends and are not material. Revenues from our PBM segment are also derived from the distribution of pharmaceuticals requiring special handling or packaging where we have been selected by the pharmaceutical manufacturer as part of a limited distribution network. These revenues include management fees received from these programs. Many of our contracts contain terms whereby we make certain financial and performance guarantees, including the minimum level of discounts or rebates a client may receive, generic utilization rates and various service guarantees. These clients may be entitled to the payment of performance penalties if we fail to meet a financial or service guarantee. Actual performance is compared to the guarantee for each measure throughout the period and accruals are recorded as an offset to revenues if we determine our performance against the guarantee indicates a potential contract liability. These estimates are adjusted to actual when the guarantee period ends and we have either met the guaranteed rate or paid amounts to clients. Historically, adjustments to our original estimates have not been material. Revenue recognition - Other Business Operations. Revenues from our Other Business Operations segment are earned from the distribution of specialty pharmaceuticals and medical supplies to providers, clinics and hospitals and performance-oriented fees paid by specialty pharmacy manufacturers. Revenues from our Other Business Operations segment are also earned through integrated medical benefit management solutions that drive cost reductions and improved quality care outcomes. Prior to the sale of UBC on December 27, 2017, revenues from our Other Business Operations also included fee-for-service arrangements which were earned from late-stage clinical trials, risk management and drug safety services associated with UBC. For contracts in which we are distributing prescription drugs, control transfers to the customer and revenues are recognized at the point of shipment. At the time of shipment, we have performed substantially all of our obligations under our customer contracts and historically have not experienced a significant level of reshipments. Receivables are recorded at the net realizable value and there are no material reserves or allowances. Since our acquisition of eviCore on December 15, 2017, Other Business Operations includes revenues from medical benefits management contracts, through which we provide innovative solutions that include utilization management using evidence based criteria, analytics, patient transparency and site of service management as well as access to certain provider specialty networks for our clients and their members. The activity involves developing clinical review criteria for provider inquiries, assessing medical necessity of treatment, and maintaining a network of providers. In some medical benefits management contracts, we earn a per-member-per month fee which is earned over the period in which our client’s eligible members are entitled to service, and in other contracts we are paid a per-claim fee for the services we provide which is earned as services are rendered. We are responsible for confirming member eligibility, performing program utilization review, potentially directing payment to the provider and accepting the financial risk of loss associated with services rendered, as specified within our client contracts. We have the ability to influence contractual fees with clients and possess the financial risk of loss in certain contractual obligations. These factors indicate we are the principal and, as such, we record gross fees contracted with clients in revenues. We provide a significant service of integrating the goods and services selected by our clients into one overall output for which the client has contracted. Thus, medical benefit management contracts generally contain a single performance obligation. The nature of our performance obligation is to stand ready to provide services over the contractual period (generally three years), but the quantity or timing of the service provided is in the control of our clients’ members. Also, our performance obligation forms a series of distinct periods of time over which we stand ready to perform. Our performance obligation is satisfied as we complete each period’s (day’s) obligations. Consideration from medical benefits management contracts is variable in nature because fees are based on member enrollment, credits due to clients and reimbursement of provider costs, all of which can vary from period to period. We have control over pricing. Contractual fees are invoiced to our clients monthly and payment terms are due within 30 days. The variable consideration in our medical benefits management contracts meets the criteria to be allocated to the distinct period of time to which it relates because (i) it is due to the activities performed to satisfy the performance obligation during that period and (ii) it represents the consideration to which we expect to be entitled. However, consideration that is impacted by more than one distinct period of service (e.g., annual credits due to clients) are estimated and allocated to the entire period to which performance relates. Certain arrangements in our medical benefit management contracts include provisions that require us to share with the client the costs or profits of the program in the event medical claims experience is above or below certain specified targets as set forth in the respective contract. The final settlement is dependent on each distinct day’s performance within the annual measurement period but cannot be allocated to specific days until the full measurement period has occurred and performance can be assessed. As such, this is a form of variable consideration estimated at contract inception and updated through the measurement period (i.e. the contract year), to the extent the risk of reversal does not exist and the consideration is not constrained. The estimated profits and costs are recognized net in revenues. Rebate accounting. We administer a rebate program through which we receive rebates and administrative fees from pharmaceutical manufacturers. If rebates are provided in conjunction with claims processing and home delivery services provided to clients in PBM contracts, they are not considered distinct within the contract from claim processing and other PBM services. Rebates are considered a form of variable consideration. Rebates and administrative fees earned for the administration of this program are recorded as a reduction of cost of revenues and the portion of the rebate and administrative fees payable to clients is treated as a reduction of revenues. The portion of rebates and administrative fees payable to clients is calculated based on historical and/or anticipated sharing percentages as defined within our contracts with clients. These payables are adjusted to actual when amounts are paid to clients subsequent to collections from pharmaceutical manufacturers; historically, these adjustments have not been material. We pay all or a contractually agreed upon portion of such rebates to our clients. We record rebates and administrative fees receivable from the manufacturer and payable to clients when the prescriptions covered under contractual agreements with the manufacturers are dispensed; this is the period to which this variable consideration relates and to which it is allocated, and rebate amounts are not dependent upon future purchases with the pharmaceutical company. If rebates are provided in a contract with a customer that does not include claims processing, our performance obligation is to arrange for the customer to receive rebates from pharmaceutical manufacturers. Rebates and administrative fees for these services are recorded in revenue, net of rebates and administrative fees payable to the customer. Reserves for estimated uncollectible rebates from the manufacturers are included in accounts receivable. Disaggregated revenue. The following table disaggregates our revenue by product and service, distribution method, and segment: (in millions) PBM (1) Other Business Operations (2) Total For the three months ended March 31, 2018 Product revenues: Network revenues (3)(4) $ 12,262.5 $ — $ 12,262.5 Home delivery and specialty revenues (4)(5) 10,602.7 — 10,602.7 Other revenues — 956.3 956.3 Product revenues 22,865.2 956.3 23,821.5 Service revenues 307.3 640.6 947.9 Total revenues 23,172.5 1,596.9 24,769.4 For the three months ended March 31, 2017 Product revenues: Network revenues (3) $ 12,406.4 $ — $ 12,406.4 Home delivery and specialty revenues (5) 10,828.4 — 10,828.4 Other revenues (6) — 1,010.2 1,010.2 Product revenues 23,234.8 1,010.2 24,245.0 Service revenues 326.5 83.4 409.9 Total revenues 23,561.3 1,093.6 24,654.9 (1) Includes the results of operations for myMatrixx subsequent to acquisition on May 15, 2017. (2) Includes the results of operations for eviCore subsequent to acquisition on December 15, 2017, and results of operations for UBC prior to its sale on December 27, 2017. (3) Includes retail pharmacy co-payments of $2,492.4 million and $2,466.3 million for the three months ended March 31, 2018 and 2017 , respectively. (4) Includes the impact of the increase to both revenues and cost of revenues of $798.8 million related to the adoption of ASC Topic 606 effective January 1, 2018. (5) Includes home delivery and specialty, including drugs we distribute to other PBMs’ clients under limited distribution contracts with pharmaceutical manufacturers and Freedom Fertility claims. (6) Includes other revenues related to drugs distributed through patient assistance programs, which were disposed of as part of the sale of UBC on December 27, 2017. Contract balances. For PBM contracts, contract liabilities arise due to financial and performance guarantees that we have made to our clients. We measure our performance against these guarantees throughout the period and recognize a contract liability as indicated by our performance. Guarantees also fluctuate based on the timing of payments. Our contract liability balance was $885.1 million and $785.6 million as of March 31, 2018 and December 31, 2017, respectively, and are presented within the “Accrued expenses” line item of the consolidated balance sheet. Contract liabilities balances also arise when we receive set-up fees or other up-front fees from our customers. This is generally uncommon, but may occur in some cases when we onboard a new client. Upfront fees are recognized as revenue over the contract term (generally three years). We have no material contract asset balances as of March 31, 2018 or December 31, 2017. Transaction price allocated to remaining performance obligations. As described above, our performance obligation forms a series of distinct periods of time over which we stand ready to perform, and is satisfied as we complete our obligation. Our contracts with PBM customers generally have a term of three years, while our specialty distribution contracts generally have a term of less than 30 days because each sale of prescription drugs is a separate contract. Our contracts to manage medical benefits and provide utilization management services generally have a term of three years. Since the remaining variable consideration will be allocated to a wholly unsatisfied promise that forms part of a single performance obligation recognized under the series guidance, we have applied the optional exemption to exclude this disclosure.

Fair value measurements

Fair value measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair value measurements	Note 3 - Fair value measurements Authoritative guidance regarding fair value measurement establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets for identical assets or liabilities; Level 2, defined as inputs other than quoted prices for similar assets and liabilities in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs for which little or no market data exists, therefore requiring an entity to develop its own assumptions. Cash and cash equivalents include cash and investments in AAA-rated money market mutual funds with original maturities of less than 90 days . Cash and cash equivalents are stated at cost, which approximates fair value. These investments are classified within Level 1 of the fair value hierarchy because they are valued using quoted prices in active markets. The fair values of receivables, claims and rebates payable and accounts payable approximate carrying values due to the short-term maturities of these instruments. The fair values, which approximate the carrying values, of our 2015 five-year term loan (Level 2) and commercial paper borrowings (Level 2) (as defined in Note 8 - Financing ) were estimated using the current market rates for debt with similar maturities. The fair values of our senior notes, which are estimated based on observable market information (Level 2), were $12,996.7 million and $14,215.7 million as of March 31, 2018 and December 31, 2017 , respectively. See Note 8 - Financing for further description of the carrying values of our debt. In determining the fair values of liabilities, we took into consideration the risk of nonperformance. Nonperformance risk refers to the risk the obligation will not be fulfilled and affects the value at which the liability would be transferred to a market participant. This risk did not have a material impact on the fair values of our liabilities.

Receivables, net

Receivables, net	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Receivables, net	Note 4 - Receivables, net Included within “Receivables, net” are the following, which are reflected net of our allowance for doubtful accounts, customer credit allowances and contractual allowances: (in millions) March 31, December 31, Trade receivables, net of total reserves and allowances of $455.5 million and $466.6, respectively $ 3,846.8 $ 4,101.6 Pharmaceutical manufacturers receivables, net of contractual allowances for certain rebates receivable of $423.3 million and $414.1 million, respectively 2,565.7 2,580.8 Other receivables 381.1 373.9 Total receivables, net $ 6,793.6 $ 7,056.3

Acquistion

Acquistion	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Acquisition	Note 5 - Acquisition eviCore acquisition. Effective December 15, 2017, we acquired 100% of eviCore, a leading provider of integrated medical benefit management solutions that drive cost reductions and improved quality care outcomes, for approximately $3.6 billion . eviCore manages benefits in categories including radiology, cardiology, musculoskeletal disorders, post-acute care and medical oncology, and contracts with health plans and commercial clients to promote the appropriate use of healthcare services. eviCore is reported within our Other Business Operations segment. We executed a contingent arrangement with certain equity holders, who are key employees of eviCore, in which $81.1 million will be paid, 50% upon each of the second and third anniversaries of the effective date of the merger. The employment arrangements provide payments are forfeited if the employee voluntarily terminates prior to the anniversary dates. The payments are accrued over the three -year period as post combination services are rendered and included as compensation costs within “Selling, general, and administrative” expense in our consolidated statement of operations. The consolidated statement of operations for the three months ended March 31, 2018 includes eviCore’s revenues of $640.7 million and net loss of $6.1 million . Net loss includes $10.4 million related to the contingent arrangement described above and amortization expense. The following represents the unaudited pro forma consolidated income statement as if eviCore had been included in the consolidated results of the Company’s operations for the three months ended March 31, 2017 . These amounts have been calculated after applying the Company’s accounting policies and adjusting the results of eviCore to reflect the additional depreciation and amortization that would have been charged assuming the fair value adjustments to intangible assets, redemption of debt outstanding and transaction costs incurred had been applied as of January 1, 2016, together with the consequential tax effects. (in millions, except per share data) For the three months ended March 31, 2017 Total revenues $ 25,149.9 Net income attributable to Express Scripts 527.5 Basic earnings per share 0.88 Diluted earnings per share $ 0.87 The following table summarizes the estimated fair values of the assets acquired and liabilities assumed at the acquisition date. (in millions) Amounts Recognized as of Acquisition Date Current assets $ 494.7 Property and equipment 15.2 Computer software 89.7 Goodwill 1,703.3 Acquired intangible assets 2,328.8 Other noncurrent assets 2.9 Current liabilities (387.4 ) Deferred income taxes (592.3 ) Other noncurrent liabilities (9.0 ) Total $ 3,645.9 A portion of the excess of purchase price over tangible net assets acquired has been allocated to intangible assets. The acquired intangible assets have been valued using an income approach, which includes unobservable inputs such as assumptions regarding revenues, gross profit, growth rates and discount rates based on the forecasted business plan, economic projections, anticipated future cash flows and marketplace data. The acquired intangible assets are amortized on a basis that approximates the pattern of benefit: Asset Value (in millions) Weighted-average amortization period (in years) Trade name $ 56.1 10.0 Customer relationships 2,272.7 20.0 Total intangibles $ 2,328.8 19.8 The excess of purchase price over tangible net assets and identified intangible assets acquired, $1,703.3 million , has been allocated to goodwill. The goodwill recognized as part of the acquisition is reported under our Other Business Operations segment and primarily reflects future economic benefits expected to arise from the Company’s growth within the medical benefit management market and the assembled workforce acquired. Approximately $397.0 million of the goodwill recognized is expected to be deductible for income tax purposes.

Goodwill and other intangible a

Goodwill and other intangible assets	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and other intangible assets	Note 6 - Goodwill and other intangible assets Following is a summary of our goodwill and other intangible assets for our two reportable segments, PBM and Other Business Operations. March 31, 2018 December 31, 2017 (in millions) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Goodwill PBM $ 29,434.2 $ (106.8 ) $ 29,327.4 $ 29,434.9 $ (107.0 ) $ 29,327.9 Other Business Operations 1,777.7 — 1,777.7 1,771.8 — 1,771.8 $ 31,211.9 $ (106.8 ) $ 31,105.1 $ 31,206.7 $ (107.0 ) $ 31,099.7 Other intangible assets PBM Customer contracts $ 17,530.3 $ (10,685.2 ) $ 6,845.1 $ 17,579.0 $ (10,378.4 ) $ 7,200.6 Trade names 232.5 (134.6 ) 97.9 232.5 (128.8 ) 103.7 17,762.8 (10,819.8 ) 6,943.0 17,811.5 (10,507.2 ) 7,304.3 Other Business Operations Customer relationships 2,282.5 (47.6 ) 2,234.9 2,272.7 (7.0 ) 2,265.7 Trade names 56.7 (1.8 ) 54.9 56.1 (0.2 ) 55.9 2,339.2 (49.4 ) 2,289.8 2,328.8 (7.2 ) 2,321.6 Total other intangible assets $ 20,102.0 $ (10,869.2 ) $ 9,232.8 $ 20,140.3 $ (10,514.4 ) $ 9,625.9 Following is a summary of the change in the net carrying value of goodwill by reportable segment: (in millions) PBM Other Business Operations Total Balance at December 31, 2017 $ 29,327.9 $ 1,771.8 $ 31,099.7 Acquisitions (1) — 5.9 5.9 Foreign currency translation (0.5 ) — (0.5 ) Balance at March 31, 2018 $ 29,327.4 $ 1,777.7 $ 31,105.1 (1) Represents the acquisition of a company by eviCore in the first quarter of 2018. The acquisition is not material to our consolidated financial statements. Purchase accounting is still being finalized in relation to this acquisition. The aggregate amount of amortization expense of other intangible assets was $403.5 million and $362.4 million for the three months ended March 31, 2018 and 2017 , respectively. Included in total amortization expense is $55.4 million , for both the three months ended March 31, 2018 and 2017 , related to our 10 -year contract with Anthem, Inc. (“Anthem”) to provide PBM services to members of the affiliated health plans of Anthem, which is included as an offset to revenues. The weighted-average amortization period of intangible assets subject to amortization is 16 years, and by major intangible asset class is 10 to 20 years for customer contracts and relationships and 6 to 10 years for trade names (excluding legacy Express Scripts, Inc. (“ESI”) trade names which have an indefinite life).

Earnings per share

Earnings per share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings per share	Note 7 - Earnings per share Basic EPS is computed using the weighted-average number of common shares outstanding during the period. Diluted EPS is computed in the same manner as basic EPS, but adds the number of additional common shares that would have been outstanding for the period if the dilutive potential common shares had been issued. All shares are calculated under the “treasury stock” method. Following is the reconciliation between the number of weighted-average shares used in the basic and diluted EPS calculations: Three Months Ended March 31, (in millions) 2018 2017 Weighted-average number of common shares outstanding during the period—basic 562.8 601.0 Dilutive common stock equivalents: (1) Outstanding stock options, restricted stock units and executive deferred compensation units 4.3 4.1 Weighted-average number of common shares outstanding during the period—diluted 567.1 605.1 (1) Excludes equity award shares of 4.5 million and 9.0 million for the three months ended March 31, 2018 and 2017 , respectively, because the effect is anti-dilutive.

Financing

Financing	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Financing	Note 8 - Financing Our debt, issued by ESI, Medco Health Solutions, Inc. (“Medco”) and us, net of unamortized discounts, premiums and financing costs, consists of: March 31, December 31, Long-term Debt Issuer Basis Points (1) Carrying Amount (in millions) Commercial paper $3,500.0 million, commercial paper program (2) Express Scripts N/A $ — $ 194.8 Senior notes (3) $1,200.0 million, 7.125% senior notes due March 2018 (4) Medco 50 — 838.1 $1,000.0 million, 2.250% senior notes due June 2019 (4) Express Scripts 15 997.6 997.1 $500.0 million, 7.250% senior notes due June 2019 (4) ESI 50 336.8 336.7 $500.0 million, 4.125% senior notes due September 2020 (4) Medco 25 502.7 502.9 $500.0 million, 2.600% senior notes due November 2020 (4) Express Scripts 15 497.1 496.9 $400.0 million, floating rate senior notes due November 2020 (5) Express Scripts N/A 397.8 397.6 $500.0 million, 3.300% senior notes due February 2021 (4) Express Scripts 35 497.1 496.9 $1,250.0 million, 4.750% senior notes due November 2021 (4) Express Scripts 45 1,242.1 1,241.6 $1,000.0 million, 3.900% senior notes due February 2022 (4) Express Scripts 40 987.8 987.0 $500.0 million, 3.050% senior notes due November 2022 (4) Express Scripts 15 495.4 495.2 $1,000.0 million, 3.000% senior notes due July 2023 (4) Express Scripts 25 993.9 993.6 $1,000.0 million, 3.500% senior notes due June 2024 (4) Express Scripts 20 990.2 989.8 $1,500.0 million, 4.500% senior notes due February 2026 (4) Express Scripts 45 1,483.6 1,483.1 $1,500.0 million, 3.400% senior notes due March 2027 (6) Express Scripts 30 1,490.1 1,489.8 $700.0 million, 6.125% senior notes due November 2041 (4) Express Scripts 50 444.2 444.2 $1,500.0 million, 4.800% senior notes due July 2046 (4) Express Scripts 40 1,483.7 1,483.6 Total senior notes 12,840.1 13,674.1 Term loan $3,000.0 million, term loan due April 2020 (7) Express Scripts N/A 2,146.0 2,145.5 Total debt 14,986.1 16,014.4 Current maturities of debt $3,500.0 million, commercial paper program (2) Express Scripts N/A — 194.8 $1,200.0 million, 7.125% senior notes due March 2018 (3)(4) Medco 50 — 838.1 $3,000.0 million, term loan due April 2020 (7) Express Scripts N/A 85.6 — Total short-term debt and current maturities of long-term debt 85.6 1,032.9 Total long-term debt $ 14,900.5 $ 14,981.5 (1) All senior notes, except for the floating rate senior notes due November 2020, are redeemable prior to maturity at a price equal to the greater of (1) 100% of the aggregate principal amount of any notes being redeemed; or (2) the sum of the present values of the remaining scheduled payments of principal and interest on the notes being redeemed discounted to the redemption date on a semiannual basis (assuming a 360 -day year consisting of twelve 30 -day months) at the treasury rate plus the basis points as indicated, plus in each case, unpaid interest on the notes being redeemed accrued to the redemption date. The floating rate senior notes due November 2020 are redeemable prior to maturity at any time on or after December 3, 2018, at a redemption price equal to 100% of the principal amount of the notes being redeemed plus accrued and unpaid interest on the principal amount being redeemed. (2) The commercial paper program (defined below) had weighted-average daily short-term borrowings of $129.4 million and $220.1 million and an average interest rate of 1.83% and 1.49% from January 1, 2018 through March 31, 2018 and from inception of the program through December 31, 2017 , respectively. (3) All senior notes are jointly and severally and fully and unconditionally (subject to certain customary release provisions, including sale, exchange, transfer or liquidation of the guarantor subsidiary) guaranteed on a senior unsecured basis by Express Scripts, ESI and Medco. See Note 15 - Condensed consolidating financial information regarding the modification of our subsidiary guarantors. (4) Senior notes require interest to be paid semi-annually, commencing six months subsequent to issuance. (5) The floating rate senior notes due November 2020 require interest to be paid quarterly beginning on March 1, 2018, until November 30, 2020 and had an average interest rate of 2.40% and 2.23% from January 1, 2018 through March 31, 2018 and from inception of the note through December 31, 2017 , respectively. (6) Senior notes require interest to be paid semi-annually in March and September. (7) The 2015 five-year term loan (defined below) had an average interest rate of 2.76% and 2.30% as of March 31, 2018 and December 31, 2017 , respectively. Merger Agreement with Cigna. The Merger Agreement with Cigna limits our ability to incur additional indebtedness or to modify any of the terms of our outstanding debt obligations. The Merger Agreement generally provides that until closing or termination of the Merger Agreement, we cannot, without Cigna’s consent (which shall not be unreasonably withheld, conditioned or delayed), incur, assume, endorse, guarantee or otherwise become liable for, or modify the terms of, any indebtedness or issue or sell any debt securities or calls, options, warrants or other rights to acquire any debt securities, subject to certain exceptions. Bank credit facilities. We have a credit agreement which includes a $3.5 billion revolving facility (the “ 2022 revolving facility ”) and a five-year $3.0 billion term loan (the “ 2015 five-year term loan ”). At March 31, 2018 , no amounts were drawn under the 2022 revolving facility . At March 31, 2018 , $87.5 million of the 2015 five-year term loan and a proportionate amount of unamortized financing costs were considered current maturities of long-term debt. The credit agreement requires interest to be paid, at our option, at LIBOR or an adjusted base rate, plus applicable margin. The applicable margin over LIBOR ranges from 0.805% to 1.300% for the 2022 revolving facility , depending on our consolidated leverage ratio, and ranges from 1.000% to 1.500% for the 2015 five-year term loan , depending on our consolidated leverage ratio. The applicable margin over the adjusted base rate ranges from 0.000% to 0.300% for the 2022 revolving facility , and 0.000% to 0.500% for the 2015 five-year term loan . We are required to pay commitment fees on the 2022 revolving facility , which range from 0.070% to 0.200% of the revolving loan commitments, depending on our credit ratings and consolidated leverage ratio. As of March 31, 2018 , we have one additional credit agreement providing for a $150.0 million uncommitted revolving credit facility executed August 2015 and amended most recently in May 2017 with a termination date of May 5, 2018. As of March 31, 2018 , no amounts were drawn under this facility. In February 2018, we terminated a separate $130.0 million uncommitted revolving credit facility. Commercial paper. We have a commercial paper program under which we may issue short-term, unsecured commercial paper notes from time to time on a private placement basis up to a maximum aggregate amount outstanding at any time of $3.5 billion . The commercial paper program does not increase our borrowing capacity as it is fully backed by our 2022 revolving facility . The commercial paper notes will be jointly and severally and fully and unconditionally guaranteed on a senior unsecured basis by ESI, Medco and us. There were no commercial paper notes outstanding as of March 31, 2018 . Covenants. Our bank financing arrangements and senior notes contain certain customary covenants that restrict our ability to incur additional indebtedness, create or permit liens on assets and engage in mergers or consolidations. The covenants related to bank financing arrangements also include, among other things, a maximum leverage ratio. See above for description of the impact of the Merger Agreement on our financing activities. At March 31, 2018 , we were in compliance with all covenants associated with our debt instruments.

Income taxes

Income taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income taxes	Note 9 - Income taxes Our effective tax rate attributable to Express Scripts decreased to 23.7% for the three months ended March 31, 2018 , from 40.0% for the same period in 2017 primarily due to the impact of the reduction in federal corporate statutory rates from 35% to 21% due to federal tax reform legislation (the “Tax Act”) enacted on December 22, 2017 and changes in discrete tax items. We recognized a net discrete income tax charge of $1.2 million for the three months ended March 31, 2018 , compared to a net discrete income tax charge of $29.9 million for the same period in 2017 . Our 2018 net discrete income tax charge primarily relates to changes in our unrecognized tax benefits. Our 2017 net discrete income tax charge primarily relates to changes in our unrecognized tax benefits and a revaluation of our net deferred tax attributes. As of December 31, 2017, we recorded estimated provisional adjustments associated with the impacts of the remeasurement of federal net deferred tax liabilities resulting from the permanent reduction in the federal corporate tax rate to 21% and the mandatory one-time tax on accumulated earning of our foreign subsidiaries. We have not made any additional measurement period adjustments related to these items during the three months ended March 31, 2018, but we could make adjustments to the provisional amounts in the future based on any additional guidance issued by the U.S. Treasury Department, the Internal Revenue Service or other standard setting bodies.

Common stock

Common stock	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity Note [Abstract]
Common stock	Note 10 - Common stock Under our share repurchase program, we repurchased 5.4 million shares for $411.3 million during the three months ended March 31, 2018 and 13.3 million shares for $902.6 million during the three months ended March 31, 2017 . As of March 31, 2018 , there were 72.9 million shares remaining under our share repurchase program. Share repurchases, made during the three months ended March 31, 2018 , were made pursuant to a Rule 10b5-1 plan implemented on November 28, 2017 (the “November 2017 Rule 10b5-1 plan”). The November 2017 Rule 10b5-1 plan was terminated on March 8, 2018. Pursuant to the Merger Agreement with Cigna, we may not, without Cigna’s consent, repurchase shares (subject to limited exceptions related to equity awards) until closing or termination of the Merger Agreement.

Stock-based compensation plans

Stock-based compensation plans	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation plans	Note 11 - Stock-based compensation plans Under the 2016 Long-Term Incentive Plan (the “ 2016 LTIP ”), we may issue stock options, stock appreciation rights (“SARs”), restricted stock awards, restricted stock units, performance shares and other types of awards. The maximum number of shares available for awards under the 2016 LTIP is 33.0 million . The maximum term of stock options, SARs, restricted stock awards, restricted stock units and performance shares granted under the 2016 LTIP is 10 years. Effective May 4, 2016, no additional awards may be granted under the 2011 Long-Term Incentive Plan (the “2011 LTIP”), the Accredo Health, Incorporated 2002 Long-Term Incentive Plan (the “Accredo Plan”), the ESI 2000 Long-Term Incentive Plan (the “2000 LTIP”) or the Medco 2002 Stock Incentive Plan (the “2002 SIP”) (except to settle awards outstanding under these plans), all of which previously authorized the grant of various equity awards with various terms to our officers, members of our Board of Directors and other key employees. However, the terms of these plans will continue to govern awards outstanding under these plans. The provisions of the 2016 LTIP , the 2011 LTIP, the Accredo Plan, the 2000 LTIP and the 2002 SIP (collectively, the “stock incentive plans”) allow employees to use shares to cover tax withholdings on equity awards (a feature which has been approved by the Compensation Committee of our Board of Directors). Upon vesting of restricted stock units and performance shares, employees have taxable income subject to statutory withholding requirements. The number of shares issued to employees may be reduced by the number of shares having a market value equal to the statutory withholding requirements for federal, state and local tax purposes. Under the stock incentive plans, we have issued stock options, restricted stock units and performance shares. All such awards are settled by issuance of new shares. Awards granted under the stock incentive plans are subject to accelerated vesting under certain specified circumstances, including upon a change in control and termination, and are also subject to forfeiture without consideration upon termination of employment under certain circumstances. The maximum term of stock options, restricted stock units and performance shares is generally 10 years. We recognized stock-based compensation expense of $32.3 million and $27.1 million in the three months ended March 31, 2018 and 2017 , respectively. Unamortized stock-based compensation expense as of March 31, 2018 was $20.6 million for stock options and $144.9 million for restricted stock units and performance shares. Stock options. During the three months ended March 31, 2018 , we granted 0.8 million stock options with a weighted-average fair market value of $16.27 per share. Stock options granted generally have three -year graded vesting. The fair value of stock options granted was estimated on the date of grant using a Black-Scholes multiple option-pricing model with the following weighted-average assumptions: Three Months Ended March 31, 2018 2017 Expected life of option 3-5 years 3-5 years Risk-free interest rate 2.4%-2.7% 1.6%-2.1% Expected volatility of stock 21%-24% 22%-23% Expected dividend yield None None The Black-Scholes model requires subjective assumptions, including future stock price volatility and expected time to exercise, which greatly affect the calculated values. The expected term and forfeiture rate of stock options granted is derived from historical data of employee exercises and post-vesting employment termination behavior as well as expected behavior on outstanding stock options. The risk-free rate is based on the United States Treasury rates in effect during the corresponding period of grant. The expected volatility is based on the historical volatility of our stock price. These factors could change in the future, which would affect the stock-based compensation expense recognized in future periods. Restricted stock units and performance shares. During the three months ended March 31, 2018 , we granted 1.6 million restricted stock units and performance shares with a weighted-average fair market value of $73.77 per share. Restricted stock units generally have three -year graded vesting. Performance shares generally have three -year cliff vesting. The number of performance shares that ultimately vest is dependent upon the achievement of specific performance metrics. The original grant of performance shares is subject to a multiplier of up to 2.5 based on the achievement of the performance metrics. Due to the achievement of certain performance metrics, during the three months ended March 31, 2018 , 0.1 million shares of common stock were issued in settlement of performance shares granted in March 2015.

Commitments and contingencies

Commitments and contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Note 12 - Commitments and contingencies We are subject to various legal proceedings, investigations, government inquiries and claims pending against us or our subsidiaries, including, but not limited to, those relating to regulatory, commercial, employment and employee benefits. We record accruals for certain of our outstanding legal proceedings, investigations and claims when we believe it is probable a liability will be incurred and the amount of loss can be reasonably estimated. On a quarterly basis, we evaluate developments in legal proceedings, investigations and claims that could affect the amount of any accrual, as well as any developments that would make a loss both probable and reasonably estimable. We record self-insurance accruals based on estimates of the aggregate liability of claim costs (including defense costs) in excess of our insurance coverage. The majority of these claims are legal claims and our liability estimate is primarily related to the cost to defend these claims. We do not accrue for settlements, judgments, monetary fines or penalties until such amounts are probable and estimable. If the range of possible loss is broad, and no amount within the range is more likely than any other, the liability accrual is based on the low end of the range. When a loss contingency is not believed to be both probable and estimable, we do not establish an accrued liability. However, if the loss (or an additional loss in excess of the accrual) is believed to be at least a reasonable possibility and material, we disclose an estimate of the possible loss or range of loss, if such estimate can be made, or disclose an estimate cannot be made. The legal proceedings, investigations, government inquiries and claims pending against us or our subsidiaries include, among others, multi-district litigation, class action lawsuits, antitrust allegations, qui tam lawsuits (“whistleblower” actions) and various governmental inquiries and informational subpoenas. The assessment of whether a loss is probable and reasonably estimable involves a series of complex judgments about future events. We are often unable to estimate a range of loss due to significant uncertainties, particularly where (i) the damages sought are unspecified or indeterminate; (ii) the proceedings are in the early stages; (iii) the matters involve novel or unsettled legal theories or a large number of parties; (iv) class action status may be sought and certified; (v) it is questionable whether asserted claims or allegations will survive dispositive motion practice; (vi) the impact of discovery on the legal process is unknown; (vii) the settlement posture of the parties has not been determined and/or (viii) in the case of certain government agency investigations, whether a sealed qui tam lawsuit has been filed and whether the government agency makes a decision to intervene in the lawsuit following investigation. Accordingly, for many proceedings, we are currently unable to estimate the loss or a range of possible loss. For a limited number of proceedings, we may be able to reasonably estimate the possible range of loss in excess of any accruals. However, we believe such proceedings, individually and in the aggregate, when finally resolved, are not reasonably likely to have a material adverse effect on our cash flow or financial condition. We also believe any amount that could be reasonably estimated in excess of accruals, if any, for such proceedings is not material. However, an unexpected adverse resolution of one or more of such matters could have a material adverse effect on our results of operations in a particular quarter or fiscal year. For purposes of this Note 12, the “Company” refers to Express Scripts Holding Company and its subsidiaries if named as defendants or identified as the subjects in the matters described below. We cannot predict the timing or outcome of the matters described below: • Jerry Beeman, et al. v. Caremark, et al. Plaintiffs allege that the Company and the other defendants failed to comply with statutory obligations to provide California clients with the results of a bi-annual survey of retail drug prices. On November 14, 2016, the district court denied plaintiffs’ motion for class certification, holding that the proposed class representatives and counsel were inadequate to represent a class. On October 6, 2017, defendants moved for sanctions against plaintiffs for destroying evidence, requesting the case be dismissed with prejudice, which the court granted on January 4, 2018, and plaintiffs are appealing. • Anthem, Inc. v. Express Scripts, Inc. Anthem, Inc. (for purposes of this Note 12, “Anthem”) filed this lawsuit alleging various breach of contract claims against the Company relating to the parties’ rights and obligations under the periodic pricing review section of the pharmacy benefit management agreement between the parties, including allegations that the Company failed to negotiate new pricing concessions in good faith, as well as various alleged service issues. Anthem requests the court enter declaratory judgment that the Company is required to provide Anthem competitive benchmark pricing, that Anthem can terminate the agreement, and that the Company is required to provide Anthem with post-termination services at competitive benchmark pricing for one year following any termination by Anthem. Anthem claims it is entitled to $13.0 billion in additional pricing concessions over the remaining term of the agreement as well as $1.8 billion for one year following any contract termination by Anthem, and $150.0 million in damages for service issues (for purposes of this Note 12, “Anthem’s Allegations”). On April 19, 2016, in response to Anthem’s complaint, the Company filed its answer denying Anthem’s Allegations in their entirety and asserting affirmative defenses and counterclaims against Anthem. The court subsequently granted Anthem’s motion to dismiss two of six counts of the Company’s amended counterclaims. • In re Express Scripts Holding Company Securities Litigation. Plaintiff filed this putative securities class action complaint on behalf of all persons or entities that purchased or otherwise acquired the Company’s publicly traded common stock between February 24, 2015 and March 21, 2016, and alleges the Company and named individuals violated Sections 10(b) and 20(a) of the Exchange Act and Rule 10b-5 by carrying out a scheme to defraud the investing public. Plaintiff seeks compensatory damages in favor of plaintiff and other class members, attorneys’ fees and costs, and equitable relief. Plaintiff adopts many of Anthem’s Allegations in support of their claim. On August 1, 2017, the court granted the Company’s motion to dismiss the complaint in its entirety. On August 30, 2017, Plaintiff filed an amended complaint alleging similar claims. On November 20, 2017, defendants filed a motion to dismiss the second amended complaint, which has been fully briefed and is ripe for the court’s consideration. • M. Scott Brewer, et al., in their capacities as Trustees for the Carpenters Pension Fund of West Virginia, derivatively on behalf of Express Scripts Holding Company v. Maura C. Breen, et al. Plaintiffs filed this stockholder derivative lawsuit alleging certain current and former officers and directors of the Company breached fiduciary duties and were unjustly enriched and also asserting a claim for corporate waste. Plaintiffs adopt many of Anthem’s Allegations in support of their claim. Plaintiffs seek damages on behalf of the Company from the individual defendants, an accounting by the individual defendants for all damages, profits, special benefits and unjust enrichment and imposition of a constructive trust, judgment directing the Company to take all necessary actions to reform and improve its corporate governance and internal control procedures, punitive damages, and an award of attorneys’ fees and costs. On January 23, 2018, the court granted defendants’ motion to dismiss the case in its entirety without prejudice. Plaintiffs filed an amended complaint on February 28, 2018. • Randy Green v. George Paz, et al. Plaintiff alleges certain current and former officers and directors of the Company breached fiduciary duties and were unjustly enriched. Plaintiff adopts many of Anthem’s Allegations in support of his claims that individual defendants breached fiduciary duties of loyalty, good faith, fair dealing, and candor, which caused the Company to issue false and misleading statements regarding the Company’s relationship with Anthem, and for contribution to and indemnification of the Company in connection with all claims that have been, are, or may in the future be asserted against the Company because of the individual defendants’ wrongdoing. On June 12, 2017, the court stayed this action until resolution of the Carpenters derivative action, described above, in the United States District Court for the Southern District of New York. • Missouri State Action (Circuit Court of St. Louis County, State of Missouri). The following three cases have been consolidated in Missouri state court: Abraham Neufeld, derivatively on behalf of nominal defendant Express Scripts Holding Company v. George Paz, et al. ; Robert Jessup, derivatively on behalf of Express Scripts Holding Company v. Timothy Wentworth, et al. ; and Richard Weisglas, derivatively on behalf of Express Scripts Holding Company v. Express Scripts Holding Company, George Paz, et al. These cases were consolidated on December 21, 2016, and on April 13, 2017, plaintiffs filed a consolidated amended complaint. Plaintiffs’ consolidated amended complaint alleges certain current and former officers and directors of the Company breached fiduciary duties and were unjustly enriched, and that certain defendants engaged in “insider selling.” Plaintiffs adopt many of Anthem’s Allegations in support of their claims that the individual defendants breached fiduciary duties of loyalty, good faith, candor, and due care, which caused the Company to issue false and misleading statements regarding the Company’s relationship with Anthem. Plaintiffs seek damages on behalf of the Company from the individual defendants, equitable relief, and attorneys’ fees and costs. On August 11, 2017, the court stayed this action until resolution of the Carpenters derivative action, described above, in the United States District Court for the Southern District of New York. • Kurt Wilson v. George Paz, et al. Plaintiff alleges that certain current and former officers and directors of the Company breached fiduciary duties, were unjustly enriched, committed abuse of control and gross mismanagement, and that certain defendants engaged in “insider selling.” Plaintiff adopts many of Anthem’s Allegations in support of the claims that the individual defendants breached fiduciary duties of loyalty, good faith, candor, and due care, which caused the Company to issue false and misleading statements regarding the Company’s relationship with Anthem. Plaintiff seeks damages on behalf of the Company from the individual defendants, equitable relief, and attorneys’ fees and costs. On December 8, 2017, the court stayed this action until resolution of the Carpenters derivative action, described above, in the United States District Court for the Southern District of New York. • In re Express Scripts/Anthem ERISA Litigation (consolidating John Doe One and John Doe Two v. Express Scripts, Inc. and Karen Burnett, Brendan Farrell, and Robert Shullich v. Express Scripts, Inc. and Anthem, Inc. ). Plaintiffs filed a Second Amended Consolidated Class Action Complaint on behalf of health plan beneficiaries who are enrolled in health care plans that are insured or administered by Anthem. Plaintiffs allege that the Company and Anthem breached fiduciary duties and otherwise violated their legal obligations under ERISA, that the Company engaged in mail fraud, wire fraud and other racketeering activity through its invoicing system with Anthem, that the Company breached its contract with Anthem, that plaintiffs are entitled to equitable relief under theories including unjust enrichment, that the Company violated unfair and deceptive trade practices statutes, that Anthem breached the covenant of good faith and fair dealing implied in health plans, and that ESI violated the anti-discrimination provisions of the Affordable Care Act. Plaintiffs adopt many of Anthem’s Allegations in support of their claim. Plaintiffs seek compensatory damages, declaratory relief, equitable relief and attorneys’ fees and costs. The Company’s motion to dismiss was granted on January 5, 2018. On April 11, 2018, plaintiffs filed an appellate brief. • Jeanine Prescott, et al. v. CVS Health Corporation, et al. Plaintiffs allege, inter alia , that the defendants entered into “exclusionary” agreements that granted exclusive formulary placement for certain blood glucose test strips in return for higher rebate payments. The complaint alleges that these agreements had the effect of driving up the costs of such test strips for the putative class members and violated RICO, ERISA and the competition and consumer protection laws of various states. Plaintiffs seek treble damages, equitable relief and attorneys’ fees and costs. On November 28, 2017, the court granted the motion of certain defendants, including the Company, to transfer this action to the United States District Court for the District of New Jersey. • Michael Bewley, et al. v. CVS Health Corporation, et al. Plaintiffs allege, inter alia , that the defendants entered into “exclusionary” agreements that granted exclusive formulary placement for certain glucagon products in return for higher rebate payments. The complaint alleges that these agreements had the effect of driving up the costs of such products for the putative class members and violated Sections 1 and 3 of the Sherman Act, RICO, ERISA and the competition and consumer protection laws of various states, U.S. territories and the District of Columbia. Plaintiffs seek treble damages, equitable relief and attorneys’ fees and costs. On November 7, 2017, the court granted defendants’ motion to transfer this action to the United States District Court for the District of New Jersey. • In re: EpiPen ERISA Litigation . Plaintiffs filed a consolidated class action complaint on April 2, 2018, alleging that defendants violated legal obligations under ERISA by negotiating increasingly large rebates from Mylan, which allegedly caused an increase in the price of EpiPen products. Plaintiffs further allege that defendants retained a significant portion of rebates, rather than passing them on to class members (who are participants in, or beneficiaries of, health insurance plans governed by ERISA who purchased EpiPen products). • City of Rockford and Acument Global Technologies, Inc. v. Mallinckrodt ARD, Inc., f/k/a Questcor Pharmaceuticals, Inc., Mallinckrodt plc, Express Scripts Holding Company, Express Scripts, Inc., CuraScript, Inc., d/b/a CuraScript, SD, Accredo Health Group, Inc., and United BioSource Corporation. Plaintiffs filed a second amended complaint on behalf of a putative class of third party payors for Acthar and their beneficiaries alleging that Mallinckrodt ARD, Inc. and Mallinckrodt plc (for purposes of this Note 12, collectively “Mallinckrodt”), the manufacturer of Acthar, an adrenocorticotropic hormone (“ACTH”), unlawfully maintained a monopoly in an alleged market for ACTH drugs by, inter alia , acquiring its only potential competitor. Plaintiffs also allege that Mallinckrodt and the Company fixed the price of Acthar, and that alleged agreements involving CuraScript, Inc., Accredo Health Group, Inc., and United BioSource Corporation unlawfully restrain trade. Plaintiffs assert claims under Sections 1 and 2 of the Sherman Act, various state antitrust laws, and RICO, as well as claims for common law fraud and unjust enrichment. Further, the City of Rockford (“Rockford”) alleges that the Company breached its PBM Services Agreement with Rockford and asserts claims for breach of contract, promissory estoppel, and breach of the implied covenant of good faith and fair dealing, and also seeks a declaratory judgment. Plaintiffs seek treble damages, equitable relief, and attorneys’ fees and costs. On January 22, 2018, the Company defendants filed a motion to dismiss the second amended complaint, which has been fully briefed and we await the court’s ruling. • MSP Recovery Claims, Series LLC, MAO-MSO Recovery II, LLC, MSP Recovery, LLC, MSPA Claims 1, LLC v. Mallinckrodt Ard, Inc., f/k/a Questcor Pharmaceuticals, Inc., Mallinckrodt PLC, and United BioSource Corporation. Plaintiffs make similar allegations to those in the Rockford complaint filed in April 2017. Pursuant to the terms of the Company’s agreement providing for the sale of UBC, the Company has agreed to indemnify UBC for, and retain the responsibility for the defense of, this action. On February 23, 2018, UBC filed a motion to dismiss the complaint, which has been fully briefed and we await the court’s ruling. • We are the subject of various qui tam matters, including: • Health Choice Alliance, LLC, on behalf of the United States of America, et al. v. Eli Lilly and Company, Inc., Healthstar Communications, Inc., VMS Biomarketing, Covance, Inc., and United Biosource Corporation . A lawsuit was filed against Eli Lilly and Company, Inc. (“Lilly”) and its vendors, including UBC, regarding services Lilly engaged them to provide with respect to insulin drugs Humalog and Humulin and osteoporosis drug Forteo (collectively, the “Lilly Products”). Pursuant to the terms of the Company’s agreement providing for the sale of UBC, the Company has agreed to indemnify UBC for, and retain the responsibility for the defense of, this action. The relator claims that: (1) Healthstar Communications, Inc. and VMS Biomarketing assisted Lilly in providing in-kind remuneration to prescribers in the form of free nursing services to induce such prescribers to prescribe the Lilly Products; (2) Lilly contracted with and paid remuneration to nurse educators to recommend the Lilly Products; and (3) Covance, Inc. and UBC assisted Lilly in providing in-kind remuneration to prescribers in the form of reimbursement support services that saved prescribers administrative expenses, which services were provided to induce such prescribers to prescribe the Lilly Products. The relator alleges these were kickbacks that violated the federal Anti-Kickback Statute. The relator alleges that the defendants violated the federal False Claims Act and state false claims acts by submitting claims for payment for the Lilly Products to government health programs, including Medicare and Medicaid, that were rendered false by virtue of the violations of the federal Anti-Kickback Statute. The relator seeks treble damages, civil penalties and restitution. On January 12, 2018, plaintiffs filed a first amended complaint. On February 21, 2018, UBC filed a motion to dismiss the first amended complaint, which has been fully briefed and we await the court’s ruling. • We have received and intend to cooperate with various subpoenas or other requests from government agencies seeking information and have included descriptions of certain specific requests below: • Insulin/Epinephrine Pricing Investigations. The Company has received inquiries from various state Attorneys General offices in connection with pending investigations into potential unfair and deceptive acts or practices related to the pricing, reimbursement and rebates for insulin and epinephrine products and possible contracts, combinations or conspiracies in restraint of trade in the setting of prices for insulin and epinephrine products. • Opioids Investigations. The Company received a request for information from the Office of Attorney General of New York regarding steps taken by the Company to fight opioid abuse in connection with a pending investigation into opioid-related deaths, overdoses, and hospitalizations. • Relationships with Pharmaceutical Manufacturers . The Company has received inquiries relating to its contractual relationships with pharmaceutical manufacturers. Investigations under the federal False Claims Act and most state false claims acts may be initiated by the applicable government investigative body or by a qui tam relator’s filing of a complaint under court seal. If a qui tam relator’s complaint remained under seal, applicable law would restrict our ability to disclose such a fact. In addition to the foregoing matters there have arisen various legal proceedings, government investigations, inquiries and audits or claims in the ordinary course of our business now pending against us or our subsidiaries. The effect of these actions on future financial results is not subject to reasonable estimation because the proceedings are in early stages and/or considerable uncertainty exists about the outcomes. Where insurance coverage is not available for such claims, or is not cost-effective, we maintain self-insurance accruals to reduce our exposure to future legal costs, settlements and judgments related to uninsured claims. Our self-insured accruals are based on estimates of the aggregate liability for the costs of uninsured claims incurred and the retained portion of insured claims using certain actuarial assumptions followed in the insurance industry and our experience. It is not possible to predict with certainty the outcome of these claims, and we can give no assurance that any losses in excess of our insurance and any self-insurance accruals will not be material.

Enterprise value initiative

Enterprise value initiative	3 Months Ended
	Mar. 31, 2018
Restructuring and Related Activities [Abstract]
Enterprise value initiative	Note 13 - Enterprise value initiative In the third quarter of 2017, we launched a multi-year, enterprise-wide value initiative (“EVI”) to transform our organization through the end of 2021, in part due to the decision by Anthem not to renew our contract, which expires at the end of 2019. We are investing to deliver an improved experience with better engagement and greater efficiency and evolve the way we do business with patients, providers and our clients. Our EVI is currently estimated to incur a cost of approximately $600.0 million to $650.0 million , which is expected to be incurred through 2021. We incurred incremental costs within the PBM segment in order to achieve the future benefit of our enterprise value initiative. There were no such comparable costs for the three months ended March 31, 2017 . The components of these incremental costs are detailed below. (in millions) Three Months Ended March 31, 2018 Consulting and temporary labor $ 11.6 Severance and related benefit costs 3.6 Accelerated depreciation 0.4 Site closures 0.8 Technology 1.3 Total EVI costs $ 17.7 Of the total EVI costs reflected above, $5.3 million and $12.4 million is reflected in the “Cost of revenues” and “Selling, general and administrative,” respectively, within our consolidated statement of operations. In addition to the costs noted above, we have capitalized $4.8 million of software development expenditures for the three months ended March 31, 2018 . Total pre-tax charges related to our enterprise value initiative since the inception of the project through March 31, 2018 have totaled approximately $60.5 million . We did no t have material liabilities related to our enterprise value initiative as of March 31, 2018 or December 31, 2017 .

Segment information

Segment information	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Segment information	Note 14 - Segment information We report segments on the basis of products and services offered and have determined we have two reportable segments: PBM and Other Business Operations. Within the Other Business Operations segment, we have aggregated two operating segments (CuraScript Specialty Distribution and eviCore) that do not meet the quantitative and qualitative criteria to be separately reported. eviCore was acquired on December 15, 2017. Prior to UBC’s sale on December 27, 2017, the Other Business Operations segment also aggregated our UBC operating segment. Operating income is the measure used by our chief operating decision maker to assess the performance of each of our operating segments. Following is information about our reportable segments, including a reconciliation of operating income to income before income taxes for the three months ended March 31, 2018 and 2017 . (in millions) PBM (1) Other Business Operations (2) Total For the three months ended March 31, 2018 Product revenues (3) $ 22,865.2 $ 956.3 $ 23,821.5 Service revenues 307.3 640.6 947.9 Total revenues 23,172.5 1,596.9 24,769.4 Depreciation and amortization expense 446.3 52.5 498.8 Operating income 929.4 32.2 961.6 Interest income and other 12.0 Interest expense and other (154.0 ) Income before income taxes 819.6 Capital expenditures 91.9 8.5 100.4 For the three months ended March 31, 2017 Product revenues (3) $ 23,234.8 $ 1,010.2 $ 24,245.0 Service revenues (4) 326.5 83.4 409.9 Total revenues 23,561.3 1,093.6 24,654.9 Depreciation and amortization expense 439.6 6.0 445.6 Operating income 1,043.3 11.3 1,054.6 Interest income and other 6.3 Interest expense and other (145.7 ) Income before income taxes 915.2 Capital expenditures 41.6 4.2 45.8 (1) Includes the results of operations for myMatrixx Holdings, Inc. (“myMatrixx”) subsequent to its acquisition on May 15, 2017. (2) Includes the results of operations for eviCore subsequent to its acquisition on December 15, 2017, and results of operations for UBC prior to its sale on December 27, 2017. (3) Includes retail pharmacy co-payments of $2,492.4 million and $2,466.3 million for the three months ended March 31, 2018 and 2017 , respectively. Includes home delivery and specialty, including drugs we distribute to other PBMs’ clients under limited distribution contracts with pharmaceutical manufacturers and Freedom Fertility claims. Also includes the impact of the increase to revenues of $798.8 million related to the adoption of ASC Topic 606 effective January 1, 2018. (4) Includes other revenues related to drugs distributed through patient assistance programs, which were disposed of as part of the sale of UBC on December 27, 2017. PBM product revenues consist of revenues from the sale of prescription drugs by retail pharmacies in our retail pharmacy networks, revenues from the dispensing of prescription drugs from our home delivery pharmacies and revenues from the sale of certain fertility and specialty drugs. Our PBM revenues collected are primarily comprised of total prescription price, which includes a negotiated price with the client, member co-payments, fees-for-service and offsets to revenues we consider client discounts, which include manufacturer rebates and administrative fees payable to clients, obligations under financial and service guarantees to clients and pricing discounts. Other Business Operations product revenues primarily consist of distribution of specialty pharmaceuticals. PBM service revenues include fees for the administration of formulary management processing for certain client contracts that do not include claims adjudication and the dispensing of prescription drugs; as well as other fee-for-service arrangements, such as medication counseling services and certain specialty services. Other Business Operations service revenues include revenues related to medical benefit management services beginning on December 15, 2017, the date of the acquisition of eviCore, and, prior to the sale of UBC on December 27, 2017, also included revenues related to data analytics and research. We have contracts with Anthem and the United States Department of Defense which represent 18% and 12% , respectively, of consolidated revenues for the three months ended March 31, 2018 .

Condensed consolidating financi

Condensed consolidating financial information	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed consolidating financial information	Note 15 - Condensed consolidating financial information The senior notes issued by ESI, Medco and us are jointly and severally and fully and unconditionally (subject to certain customary release provisions, including sale, exchange, transfer or liquidation of the guarantor subsidiary) guaranteed by ESI, Medco and us, as applicable. The following condensed consolidating financial information has been prepared in accordance with the requirements for presentation of such information. The condensed consolidating financial information presented below is not indicative of what the financial position, results of operations or cash flows would have been had each of the entities operated as an independent company during the periods for various reasons, including, but not limited to, intercompany transactions and integration of systems. As described in Note 8 - Financing , we have a credit agreement which was amended on October 26, 2017. In connection with entering into the credit agreement, the Company sent a notice to the respective trustees under the indentures governing the Company’s outstanding senior notes (including notes issued by ESI and Medco) that, effective as of October 26, 2017, simultaneously with closing the credit agreement, each of the guarantors under such indentures, other than the Company, ESI and Medco, as applicable, was automatically released from all of its respective obligations under such indentures and its respective guarantees of the outstanding senior notes of the Company, ESI and Medco issued thereunder. As such, the historical subsidiary guarantors have been combined with the historical subsidiary non-guarantors, to reflect the new subsidiary non-guarantor presentation, as shown below. The condensed consolidating financial information is presented separately for: (i) Express Scripts (the Parent Company), the issuer of certain guaranteed obligations; (ii) ESI, guarantor, the issuer of additional guaranteed obligations; (iii) Medco, guarantor, the issuer of additional guaranteed obligations; (iv) Non-guarantor subsidiaries, on a combined basis; (v) Consolidating entries and eliminations representing adjustments to (a) eliminate intercompany transactions between or among Express Scripts, ESI, Medco and the non-guarantor subsidiaries, (b) eliminate the investments in our subsidiaries and (c) record consolidating entries; and (vi) Express Scripts and subsidiaries on a consolidated basis. In 2017, as part of an ongoing reorganization since 2015, certain subsidiaries have been merged within the structure defined above through non-cash transfers. The 2017 reorganizations qualified as a transfer of assets and are reflected prospectively in the condensed consolidating balance sheet, statement of operations and statement of cash flows. These events had no impact on our consolidated balance sheet, consolidated statement of operations or consolidated statement of cash flows. In conjunction with the ongoing reorganization, during 2017, we executed certain intercompany agreements and transfer pricing agreements effective retrospectively to January 1, 2017. These intercompany agreements resulted in increased operating expenses for our non-guarantors and reduced operating expenses for ESI in the condensed consolidating statement of operations for the three months ended March 31, 2018 , as well as changes in interest expense between Express Scripts, ESI, Medco and our non-guarantors. The transfer pricing agreements resulted in increased revenues and operating expenses for ESI, Medco and our non-guarantors with a resulting increase in the eliminations column. These events had no impact on our consolidated balance sheet, consolidated statement of operations or consolidated statement of cash flows. Condensed Consolidating Balance Sheet (in millions) Express Scripts Holding Company Express Scripts, Medco Health Solutions, Non-Guarantors Eliminations Consolidated As of March 31, 2018 Cash and cash equivalents $ 1,125.3 $ 133.5 $ — $ 1,058.8 $ — $ 2,317.6 Receivables, net — 3,435.2 785.2 2,573.2 — 6,793.6 Other current assets — 212.5 0.1 2,151.0 — 2,363.6 Total current assets 1,125.3 3,781.2 785.3 5,783.0 — 11,474.8 Property and equipment, net — 173.7 3.2 376.0 — 552.9 Computer software, net — 641.2 — 177.4 — 818.6 Investments in subsidiaries 53,200.8 14,875.6 8,994.8 — (77,071.2 ) — Intercompany — 1,403.8 1,794.6 18,446.3 (21,644.7 ) — Goodwill — 3,122.4 22,609.9 5,372.8 — 31,105.1 Other intangible assets, net — 391.3 5,665.4 3,176.1 — 9,232.8 Other assets 7.8 121.2 86.4 46.2 (40.2 ) 221.4 Total assets $ 54,333.9 $ 24,510.4 $ 39,939.6 $ 33,377.8 $ (98,756.1 ) $ 53,405.6 Claims and rebates payable $ — $ 7,463.0 $ 2,237.9 $ 268.5 $ — $ 9,969.4 Accounts payable — 842.4 27.0 3,088.0 — 3,957.4 Accrued expenses 100.1 1,084.8 313.6 1,212.2 — 2,710.7 Short-term debt and current maturities of long-term debt 85.6 — — — — 85.6 Total current liabilities 185.7 9,390.2 2,578.5 4,568.7 — 16,723.1 Long-term debt 14,061.0 336.8 502.7 — — 14,900.5 Intercompany 21,644.7 — — — (21,644.7 ) — Deferred taxes — — 1,328.6 1,208.1 (40.2 ) 2,496.5 Other liabilities — 536.0 270.4 31.0 — 837.4 Non-controlling interest — — — 5.6 — 5.6 Express Scripts stockholders’ equity 18,442.5 14,247.4 35,259.4 27,564.4 (77,071.2 ) 18,442.5 Total liabilities and stockholders’ equity $ 54,333.9 $ 24,510.4 $ 39,939.6 $ 33,377.8 $ (98,756.1 ) $ 53,405.6 Condensed Consolidating Balance Sheet (in millions) Express Scripts Holding Company Express Scripts, Medco Health Solutions, Non-Guarantors Eliminations Consolidated As of December 31, 2017 Cash and cash equivalents $ 1,031.0 $ 114.5 $ — $ 1,164.1 $ — $ 2,309.6 Receivables, net — 3,740.9 971.3 2,344.1 — 7,056.3 Other current assets — 350.7 2.1 2,238.4 — 2,591.2 Total current assets 1,031.0 4,206.1 973.4 5,746.6 — 11,957.1 Property and equipment, net — 166.1 3.2 382.0 — 551.3 Computer software, net — 640.0 — 174.9 — 814.9 Investments in subsidiaries 52,546.3 14,350.2 8,926.0 — (75,822.5 ) — Intercompany — 847.1 2,531.5 17,624.0 (21,002.6 ) — Goodwill — 3,122.4 22,609.9 5,367.4 — 31,099.7 Other intangible assets, net — 449.5 5,917.1 3,259.3 — 9,625.9 Other assets 8.2 112.6 80.3 42.7 (36.9 ) 206.9 Total assets $ 53,585.5 $ 23,894.0 $ 41,041.4 $ 32,596.9 $ (96,862.0 ) $ 54,255.8 Claims and rebates payable $ — $ 7,389.4 $ 2,574.3 $ 224.8 $ — $ 10,188.5 Accounts payable — 840.3 34.0 2,881.4 — 3,755.7 Accrued expenses 126.6 1,192.7 272.7 1,277.3 — 2,869.3 Short-term debt and current maturities of long-term debt 194.8 — 838.1 — — 1,032.9 Total current liabilities 321.4 9,422.4 3,719.1 4,383.5 — 17,846.4 Long-term debt 14,141.9 336.7 502.9 — — 14,981.5 Intercompany 21,002.6 — — — (21,002.6 ) — Deferred taxes — — 1,392.2 1,207.1 (36.9 ) 2,562.4 Other liabilities — 457.1 258.4 24.7 — 740.2 Non-controlling interest — — — 5.7 — 5.7 Express Scripts stockholders’ equity 18,119.6 13,677.8 35,168.8 26,975.9 (75,822.5 ) 18,119.6 Total liabilities and stockholders’ equity $ 53,585.5 $ 23,894.0 $ 41,041.4 $ 32,596.9 $ (96,862.0 ) $ 54,255.8 Condensed Consolidating Statement of Operations and Comprehensive Income (in millions) Express Scripts Holding Company Express Scripts, Inc. Medco Health Solutions, Inc. Non-Guarantors Eliminations Consolidated For the three months ended March 31, 2018 Revenues $ — $ 16,908.8 $ 4,250.5 $ 15,233.8 $ (11,623.7 ) $ 24,769.4 Operating expenses — 16,824.0 4,149.7 14,457.8 (11,623.7 ) 23,807.8 Operating income — 84.8 100.8 776.0 — 961.6 Other (expense) income: Interest (expense) income and other, net (158.3 ) 6.9 8.6 0.8 — (142.0 ) Intercompany interest income (expense) 159.6 (68.6 ) (78.7 ) (12.3 ) — — Other (expense) income, net 1.3 (61.7 ) (70.1 ) (11.5 ) — (142.0 ) Income before income taxes 1.3 23.1 30.7 764.5 — 819.6 Provision for income taxes 0.3 5.0 8.9 179.5 — 193.7 Income before equity in earnings of subsidiaries 1.0 18.1 21.8 585.0 — 625.9 Equity in earnings of subsidiaries 622.2 523.3 65.1 — (1,210.6 ) — Net income 623.2 541.4 86.9 585.0 (1,210.6 ) 625.9 Less: Net income attributable to non-controlling interest — — — 2.7 — 2.7 Net income attributable to Express Scripts 623.2 541.4 86.9 582.3 (1,210.6 ) 623.2 Other comprehensive loss (2.8 ) (2.8 ) — (2.8 ) 5.6 (2.8 ) Comprehensive income attributable to Express Scripts $ 620.4 $ 538.6 $ 86.9 $ 579.5 $ (1,205.0 ) $ 620.4 For the three months ended March 31, 2017 Revenues $ — $ 9,952.9 $ 4,919.5 $ 10,876.7 $ (1,094.2 ) $ 24,654.9 Operating expenses — 9,200.7 4,545.5 10,948.3 (1,094.2 ) 23,600.3 Operating income (loss) — 752.2 374.0 (71.6 ) — 1,054.6 Other (expense) income: Interest expense and other, net (124.1 ) (3.1 ) (11.0 ) (1.2 ) — (139.4 ) Intercompany interest income (expense) 49.8 (24.9 ) — (24.9 ) — — Other expense, net (74.3 ) (28.0 ) (11.0 ) (26.1 ) — (139.4 ) Income (loss) before income taxes (74.3 ) 724.2 363.0 (97.7 ) — 915.2 Provision (benefit) for income taxes (27.3 ) 293.0 151.6 (52.4 ) — 364.9 Income (loss) before equity in earnings of subsidiaries (47.0 ) 431.2 211.4 (45.3 ) — 550.3 Equity in earnings (loss) of subsidiaries 593.3 64.8 (114.1 ) — (544.0 ) — Net income (loss) 546.3 496.0 97.3 (45.3 ) (544.0 ) 550.3 Less: Net income attributable to non-controlling interest — — — 4.0 — 4.0 Net income (loss) attributable to Express Scripts 546.3 496.0 97.3 (49.3 ) (544.0 ) 546.3 Other comprehensive income 1.2 1.2 — 1.2 (2.4 ) 1.2 Comprehensive income (loss) attributable to Express Scripts $ 547.5 $ 497.2 $ 97.3 $ (48.1 ) $ (546.4 ) $ 547.5 Condensed Consolidating Statements of Cash Flows (in millions) Express Scripts Holding Company Express Scripts, Inc. Medco Health Solutions, Inc. Non-Guarantors Eliminations Consolidated For the three months ended March 31, 2018 Net cash flows provided by (used in) operating activities $ (25.3 ) $ 674.7 $ 96.0 $ 781.6 $ (15.4 ) $ 1,511.6 Cash flows from investing activities: Capital expenditures for property and equipment and computer software — (80.2 ) — (20.2 ) — (100.4 ) Acquisition of business, net of cash acquired — — — (23.1 ) — (23.1 ) Other, net — (3.7 ) — (2.3 ) — (6.0 ) Net cash used in investing activities — (83.9 ) — (45.6 ) — (129.5 ) Cash flows from financing activities: Repayment of long-term debt — — (831.4 ) — — (831.4 ) Treasury stock acquired (420.7 ) — — — — (420.7 ) Commercial paper borrowings (repayments), net (195.0 ) — — — — (195.0 ) Net proceeds from employee stock plans 82.3 — — — — 82.3 Other, net (0.1 ) (2.8 ) — (19.7 ) 15.4 (7.2 ) Net intercompany transactions 653.1 (569.0 ) 735.4 (819.5 ) — — Net cash (used in) provided by financing activities 119.6 (571.8 ) (96.0 ) (839.2 ) 15.4 (1,372.0 ) Effect of foreign currency translation adjustment — — — (2.1 ) — (2.1 ) Net increase (decrease) in cash and cash equivalents 94.3 19.0 — (105.3 ) — 8.0 Cash and cash equivalents at beginning of period 1,031.0 114.5 — 1,164.1 — 2,309.6 Cash and cash equivalents at end of period $ 1,125.3 $ 133.5 $ — $ 1,058.8 $ — $ 2,317.6 For the three months ended March 31, 2017 Net cash flows provided by (used in) operating activities $ (79.5 ) $ 725.1 $ 429.2 $ (46.4 ) $ (28.0 ) $ 1,000.4 Cash flows from investing activities: Capital expenditures for property and equipment and computer software — (32.6 ) — (13.2 ) — (45.8 ) Other, net — (4.1 ) — 1.8 — (2.3 ) Net cash used in investing activities — (36.7 ) — (11.4 ) — (48.1 ) Cash flows from financing activities: Repayment of long-term debt (37.5 ) — — — — (37.5 ) Treasury stock acquired (837.4 ) — — — — (837.4 ) Net proceeds from employee stock plans 14.5 — — — — 14.5 Other, net — — — (34.1 ) 28.0 (6.1 ) Net intercompany transactions 1,767.2 (1,123.5 ) (433.6 ) (210.1 ) — — Net cash (used in) provided by financing activities 906.8 (1,123.5 ) (433.6 ) (244.2 ) 28.0 (866.5 ) Effect of foreign currency translation adjustment — — — 0.8 — 0.8 Net increase (decrease) in cash and cash equivalents 827.3 (435.1 ) (4.4 ) (301.2 ) — 86.6 Cash and cash equivalents at beginning of period 583.5 1,234.2 4.4 1,255.1 — 3,077.2 Cash and cash equivalents at end of period $ 1,410.8 $ 799.1 $ — $ 953.9 $ — $ 3,163.8

Summary of significant accoun23

Summary of significant accounting policies - Accounting policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	Our significant accounting policies, normally included in financial statements prepared in conformity with generally accepted accounting principles, have been omitted from this Form 10-Q pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). We believe the disclosures contained in this Form 10-Q are adequate to fairly state the information when read in conjunction with the Notes to the Consolidated Financial Statements included in our consolidated financial statements for the year ended December 31, 2017 , included in Item 8 - Consolidated Financial Statements and Supplementary Data, included in our Annual Report on Form 10-K filed with the SEC on February 27, 2018 . For a description of our accounting policies, refer to the Notes to the Consolidated Financial Statements included therein. We believe the accompanying unaudited consolidated financial statements reflect all adjustments (consisting of only normal recurring adjustments) necessary to state fairly the unaudited consolidated balance sheet as of March 31, 2018 , the consolidated balance sheet as of December 31, 2017 , the unaudited consolidated statement of operations and unaudited consolidated statement of comprehensive income for the three months ended March 31, 2018 and 2017 , the unaudited consolidated statement of changes in stockholders’ equity for the three months ended March 31, 2018 , and the unaudited consolidated statement of cash flows for the three months ended March 31, 2018 and 2017 . Certain amounts in the prior year have been reclassified to conform to the current year presentation. Operating results for the three months ended March 31, 2018 are not necessarily indicative of the results that may be expected for the year ending December 31, 2018 .
New Accounting Guidance	Adopted new accounting guidance. In May 2014, Financial Accounting Standards Board (“FASB”) issued ASU 2014-09, Revenue from Contracts with Customers (ASC Topic 606), which supersedes ASC Topic 605, Revenue Recognition. The new standard requires companies to recognize revenues upon transfer of goods or services to customers in amounts that reflect the consideration which the company expects to receive in exchange for those goods or services. We adopted ASC Topic 606, as of January 1, 2018, using the modified retrospective method applied to all contracts. The effect of initially applying the new revenue standard did not result in an opening balance adjustment to retained earnings as of the beginning of the earliest comparative period presented, however, it did result in an increase to both revenues and cost of revenues for the period ended March 31, 2018. The following are the impacts of the new revenue standard upon adoption: • resulted in reclassifications between revenues and cost of revenues, • provided new guidance for evaluating performance obligations, which affected how we understand the nature of our promises to customers, the control we have in PBM arrangements, and the principal-agent analysis, and resulted in changing recognition of certain contracts from net to gross, and • required non-cash consideration associated with a certain contract where the client replenishes inventory to be recognized at fair value. These changes resulted in an increase to both revenues and cost of revenues of $798.8 million for the three months ended March 31, 2018, with no impact to gross profit. In August 2016, FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230), Classification of Certain Cash Receipts and Cash Payments. The guidance addresses the classification of cash flow related to (1) debt prepayment or extinguishment costs, (2) settlement of zero-coupon debt instruments or other debt instruments with coupon rates that are insignificant in relation to the effective interest rate of the borrowing, (3) contingent consideration payments made after a business combination, (4) proceeds from the settlement of insurance claims, (5) proceeds from the settlement of corporate-owned life insurance, including bank-owned life insurance, (6) distributions received from equity method investees and (7) beneficial interests in securitization transactions. The guidance also clarifies how the predominance principle should be applied when cash receipts and cash payments have aspects of more than one class of cash flows. The guidance is effective for financial statements issued for annual reporting periods beginning after December 15, 2017 and applied retrospectively. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230), Restricted Cash. This guidance requires amounts generally described as restricted cash and restricted cash equivalents be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. We adopted this guidance effective January 1, 2018, retrospectively, with no significant impact on our consolidated financial statements for the three months ended March 31, 2018 and 2017 . In certain historical periods, debt extinguishment costs were reclassified from an operating activity to a financing activity as a result of adoption. New accounting guidance not yet adopted . In February 2016, FASB issued ASU 2016-02, Leases (ASC Topic 842), which supersedes ASC Topic 840, Leases. This ASU is intended to increase transparency and comparability of organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The new guidance is effective for financial statements issued for annual reporting periods beginning after December 15, 2018, and early application is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.
Earnings per share, Policy	Basic EPS is computed using the weighted-average number of common shares outstanding during the period. Diluted EPS is computed in the same manner as basic EPS, but adds the number of additional common shares that would have been outstanding for the period if the dilutive potential common shares had been issued. All shares are calculated under the “treasury stock” method.

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following table disaggregates our revenue by product and service, distribution method, and segment: (in millions) PBM (1) Other Business Operations (2) Total For the three months ended March 31, 2018 Product revenues: Network revenues (3)(4) $ 12,262.5 $ — $ 12,262.5 Home delivery and specialty revenues (4)(5) 10,602.7 — 10,602.7 Other revenues — 956.3 956.3 Product revenues 22,865.2 956.3 23,821.5 Service revenues 307.3 640.6 947.9 Total revenues 23,172.5 1,596.9 24,769.4 For the three months ended March 31, 2017 Product revenues: Network revenues (3) $ 12,406.4 $ — $ 12,406.4 Home delivery and specialty revenues (5) 10,828.4 — 10,828.4 Other revenues (6) — 1,010.2 1,010.2 Product revenues 23,234.8 1,010.2 24,245.0 Service revenues 326.5 83.4 409.9 Total revenues 23,561.3 1,093.6 24,654.9 (1) Includes the results of operations for myMatrixx subsequent to acquisition on May 15, 2017. (2) Includes the results of operations for eviCore subsequent to acquisition on December 15, 2017, and results of operations for UBC prior to its sale on December 27, 2017. (3) Includes retail pharmacy co-payments of $2,492.4 million and $2,466.3 million for the three months ended March 31, 2018 and 2017 , respectively. (4) Includes the impact of the increase to both revenues and cost of revenues of $798.8 million related to the adoption of ASC Topic 606 effective January 1, 2018. (5) Includes home delivery and specialty, including drugs we distribute to other PBMs’ clients under limited distribution contracts with pharmaceutical manufacturers and Freedom Fertility claims. (6) Includes other revenues related to drugs distributed through patient assistance programs, which were disposed of as part of the sale of UBC on December 27, 2017.

Receivables, net (Tables)

Receivables, net (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Schedule of Receivables, Net	Included within “Receivables, net” are the following, which are reflected net of our allowance for doubtful accounts, customer credit allowances and contractual allowances: (in millions) March 31, December 31, Trade receivables, net of total reserves and allowances of $455.5 million and $466.6, respectively $ 3,846.8 $ 4,101.6 Pharmaceutical manufacturers receivables, net of contractual allowances for certain rebates receivable of $423.3 million and $414.1 million, respectively 2,565.7 2,580.8 Other receivables 381.1 373.9 Total receivables, net $ 6,793.6 $ 7,056.3

Acquisition (Tables)

Acquisition (Tables)	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Pro Forma Information	The following represents the unaudited pro forma consolidated income statement as if eviCore had been included in the consolidated results of the Company’s operations for the three months ended March 31, 2017 . These amounts have been calculated after applying the Company’s accounting policies and adjusting the results of eviCore to reflect the additional depreciation and amortization that would have been charged assuming the fair value adjustments to intangible assets, redemption of debt outstanding and transaction costs incurred had been applied as of January 1, 2016, together with the consequential tax effects. (in millions, except per share data) For the three months ended March 31, 2017 Total revenues $ 25,149.9 Net income attributable to Express Scripts 527.5 Basic earnings per share 0.88 Diluted earnings per share $ 0.87
Assets Acquired and Liabilities Assumed	The following table summarizes the estimated fair values of the assets acquired and liabilities assumed at the acquisition date. (in millions) Amounts Recognized as of Acquisition Date Current assets $ 494.7 Property and equipment 15.2 Computer software 89.7 Goodwill 1,703.3 Acquired intangible assets 2,328.8 Other noncurrent assets 2.9 Current liabilities (387.4 ) Deferred income taxes (592.3 ) Other noncurrent liabilities (9.0 ) Total $ 3,645.9
Finite-Lived Intangible Assets Acquired	The acquired intangible assets are amortized on a basis that approximates the pattern of benefit: Asset Value (in millions) Weighted-average amortization period (in years) Trade name $ 56.1 10.0 Customer relationships 2,272.7 20.0 Total intangibles $ 2,328.8 19.8

Goodwill and other intangible27

Goodwill and other intangible assets (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Goodwill and Other Intangible Assets	Following is a summary of our goodwill and other intangible assets for our two reportable segments, PBM and Other Business Operations. March 31, 2018 December 31, 2017 (in millions) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Goodwill PBM $ 29,434.2 $ (106.8 ) $ 29,327.4 $ 29,434.9 $ (107.0 ) $ 29,327.9 Other Business Operations 1,777.7 — 1,777.7 1,771.8 — 1,771.8 $ 31,211.9 $ (106.8 ) $ 31,105.1 $ 31,206.7 $ (107.0 ) $ 31,099.7 Other intangible assets PBM Customer contracts $ 17,530.3 $ (10,685.2 ) $ 6,845.1 $ 17,579.0 $ (10,378.4 ) $ 7,200.6 Trade names 232.5 (134.6 ) 97.9 232.5 (128.8 ) 103.7 17,762.8 (10,819.8 ) 6,943.0 17,811.5 (10,507.2 ) 7,304.3 Other Business Operations Customer relationships 2,282.5 (47.6 ) 2,234.9 2,272.7 (7.0 ) 2,265.7 Trade names 56.7 (1.8 ) 54.9 56.1 (0.2 ) 55.9 2,339.2 (49.4 ) 2,289.8 2,328.8 (7.2 ) 2,321.6 Total other intangible assets $ 20,102.0 $ (10,869.2 ) $ 9,232.8 $ 20,140.3 $ (10,514.4 ) $ 9,625.9
Summary of Change in Net Carrying Value of Goodwill by Business Segment	Following is a summary of the change in the net carrying value of goodwill by reportable segment: (in millions) PBM Other Business Operations Total Balance at December 31, 2017 $ 29,327.9 $ 1,771.8 $ 31,099.7 Acquisitions (1) — 5.9 5.9 Foreign currency translation (0.5 ) — (0.5 ) Balance at March 31, 2018 $ 29,327.4 $ 1,777.7 $ 31,105.1 (1) Represents the acquisition of a company by eviCore in the first quarter of 2018. The acquisition is not material to our consolidated financial statements. Purchase accounting is still being finalized in relation to this acquisition.

Earnings per share (Tables)

Earnings per share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Reconciliation between weighted-average shares used in basic and diluted earnings per share calculation	Following is the reconciliation between the number of weighted-average shares used in the basic and diluted EPS calculations: Three Months Ended March 31, (in millions) 2018 2017 Weighted-average number of common shares outstanding during the period—basic 562.8 601.0 Dilutive common stock equivalents: (1) Outstanding stock options, restricted stock units and executive deferred compensation units 4.3 4.1 Weighted-average number of common shares outstanding during the period—diluted 567.1 605.1 (1) Excludes equity award shares of 4.5 million and 9.0 million for the three months ended March 31, 2018 and 2017 , respectively, because the effect is anti-dilutive.

Financing (Tables)

Financing (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Summary of Company's Debt, net of Unamortized Discounts and Premiums	Our debt, issued by ESI, Medco Health Solutions, Inc. (“Medco”) and us, net of unamortized discounts, premiums and financing costs, consists of: March 31, December 31, Long-term Debt Issuer Basis Points (1) Carrying Amount (in millions) Commercial paper $3,500.0 million, commercial paper program (2) Express Scripts N/A $ — $ 194.8 Senior notes (3) $1,200.0 million, 7.125% senior notes due March 2018 (4) Medco 50 — 838.1 $1,000.0 million, 2.250% senior notes due June 2019 (4) Express Scripts 15 997.6 997.1 $500.0 million, 7.250% senior notes due June 2019 (4) ESI 50 336.8 336.7 $500.0 million, 4.125% senior notes due September 2020 (4) Medco 25 502.7 502.9 $500.0 million, 2.600% senior notes due November 2020 (4) Express Scripts 15 497.1 496.9 $400.0 million, floating rate senior notes due November 2020 (5) Express Scripts N/A 397.8 397.6 $500.0 million, 3.300% senior notes due February 2021 (4) Express Scripts 35 497.1 496.9 $1,250.0 million, 4.750% senior notes due November 2021 (4) Express Scripts 45 1,242.1 1,241.6 $1,000.0 million, 3.900% senior notes due February 2022 (4) Express Scripts 40 987.8 987.0 $500.0 million, 3.050% senior notes due November 2022 (4) Express Scripts 15 495.4 495.2 $1,000.0 million, 3.000% senior notes due July 2023 (4) Express Scripts 25 993.9 993.6 $1,000.0 million, 3.500% senior notes due June 2024 (4) Express Scripts 20 990.2 989.8 $1,500.0 million, 4.500% senior notes due February 2026 (4) Express Scripts 45 1,483.6 1,483.1 $1,500.0 million, 3.400% senior notes due March 2027 (6) Express Scripts 30 1,490.1 1,489.8 $700.0 million, 6.125% senior notes due November 2041 (4) Express Scripts 50 444.2 444.2 $1,500.0 million, 4.800% senior notes due July 2046 (4) Express Scripts 40 1,483.7 1,483.6 Total senior notes 12,840.1 13,674.1 Term loan $3,000.0 million, term loan due April 2020 (7) Express Scripts N/A 2,146.0 2,145.5 Total debt 14,986.1 16,014.4 Current maturities of debt $3,500.0 million, commercial paper program (2) Express Scripts N/A — 194.8 $1,200.0 million, 7.125% senior notes due March 2018 (3)(4) Medco 50 — 838.1 $3,000.0 million, term loan due April 2020 (7) Express Scripts N/A 85.6 — Total short-term debt and current maturities of long-term debt 85.6 1,032.9 Total long-term debt $ 14,900.5 $ 14,981.5 (1) All senior notes, except for the floating rate senior notes due November 2020, are redeemable prior to maturity at a price equal to the greater of (1) 100% of the aggregate principal amount of any notes being redeemed; or (2) the sum of the present values of the remaining scheduled payments of principal and interest on the notes being redeemed discounted to the redemption date on a semiannual basis (assuming a 360 -day year consisting of twelve 30 -day months) at the treasury rate plus the basis points as indicated, plus in each case, unpaid interest on the notes being redeemed accrued to the redemption date. The floating rate senior notes due November 2020 are redeemable prior to maturity at any time on or after December 3, 2018, at a redemption price equal to 100% of the principal amount of the notes being redeemed plus accrued and unpaid interest on the principal amount being redeemed. (2) The commercial paper program (defined below) had weighted-average daily short-term borrowings of $129.4 million and $220.1 million and an average interest rate of 1.83% and 1.49% from January 1, 2018 through March 31, 2018 and from inception of the program through December 31, 2017 , respectively. (3) All senior notes are jointly and severally and fully and unconditionally (subject to certain customary release provisions, including sale, exchange, transfer or liquidation of the guarantor subsidiary) guaranteed on a senior unsecured basis by Express Scripts, ESI and Medco. See Note 15 - Condensed consolidating financial information regarding the modification of our subsidiary guarantors. (4) Senior notes require interest to be paid semi-annually, commencing six months subsequent to issuance. (5) The floating rate senior notes due November 2020 require interest to be paid quarterly beginning on March 1, 2018, until November 30, 2020 and had an average interest rate of 2.40% and 2.23% from January 1, 2018 through March 31, 2018 and from inception of the note through December 31, 2017 , respectively. (6) Senior notes require interest to be paid semi-annually in March and September. (7) The 2015 five-year term loan (defined below) had an average interest rate of 2.76% and 2.30% as of March 31, 2018 and December 31, 2017 , respectively.

Stock-based compensation plans

Stock-based compensation plans (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Weighted-Average Assumptions to Value Options Granted	The fair value of stock options granted was estimated on the date of grant using a Black-Scholes multiple option-pricing model with the following weighted-average assumptions: Three Months Ended March 31, 2018 2017 Expected life of option 3-5 years 3-5 years Risk-free interest rate 2.4%-2.7% 1.6%-2.1% Expected volatility of stock 21%-24% 22%-23% Expected dividend yield None None

Enterprise value initiative (Ta

Enterprise value initiative (Tables)	3 Months Ended
	Mar. 31, 2018
Restructuring and Related Activities [Abstract]
Components of incremental cost	The components of these incremental costs are detailed below. (in millions) Three Months Ended March 31, 2018 Consulting and temporary labor $ 11.6 Severance and related benefit costs 3.6 Accelerated depreciation 0.4 Site closures 0.8 Technology 1.3 Total EVI costs $ 17.7

Segment information (Tables)

Segment information (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Reportable Segments Information	Following is information about our reportable segments, including a reconciliation of operating income to income before income taxes for the three months ended March 31, 2018 and 2017 . (in millions) PBM (1) Other Business Operations (2) Total For the three months ended March 31, 2018 Product revenues (3) $ 22,865.2 $ 956.3 $ 23,821.5 Service revenues 307.3 640.6 947.9 Total revenues 23,172.5 1,596.9 24,769.4 Depreciation and amortization expense 446.3 52.5 498.8 Operating income 929.4 32.2 961.6 Interest income and other 12.0 Interest expense and other (154.0 ) Income before income taxes 819.6 Capital expenditures 91.9 8.5 100.4 For the three months ended March 31, 2017 Product revenues (3) $ 23,234.8 $ 1,010.2 $ 24,245.0 Service revenues (4) 326.5 83.4 409.9 Total revenues 23,561.3 1,093.6 24,654.9 Depreciation and amortization expense 439.6 6.0 445.6 Operating income 1,043.3 11.3 1,054.6 Interest income and other 6.3 Interest expense and other (145.7 ) Income before income taxes 915.2 Capital expenditures 41.6 4.2 45.8 (1) Includes the results of operations for myMatrixx Holdings, Inc. (“myMatrixx”) subsequent to its acquisition on May 15, 2017. (2) Includes the results of operations for eviCore subsequent to its acquisition on December 15, 2017, and results of operations for UBC prior to its sale on December 27, 2017. (3) Includes retail pharmacy co-payments of $2,492.4 million and $2,466.3 million for the three months ended March 31, 2018 and 2017 , respectively. Includes home delivery and specialty, including drugs we distribute to other PBMs’ clients under limited distribution contracts with pharmaceutical manufacturers and Freedom Fertility claims. Also includes the impact of the increase to revenues of $798.8 million related to the adoption of ASC Topic 606 effective January 1, 2018. (4) Includes other revenues related to drugs distributed through patient assistance programs, which were disposed of as part of the sale of UBC on December 27, 2017.

Condensed consolidating finan33

Condensed consolidating financial information (Tables)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Consolidating Balance Sheet	Condensed Consolidating Balance Sheet (in millions) Express Scripts Holding Company Express Scripts, Medco Health Solutions, Non-Guarantors Eliminations Consolidated As of March 31, 2018 Cash and cash equivalents $ 1,125.3 $ 133.5 $ — $ 1,058.8 $ — $ 2,317.6 Receivables, net — 3,435.2 785.2 2,573.2 — 6,793.6 Other current assets — 212.5 0.1 2,151.0 — 2,363.6 Total current assets 1,125.3 3,781.2 785.3 5,783.0 — 11,474.8 Property and equipment, net — 173.7 3.2 376.0 — 552.9 Computer software, net — 641.2 — 177.4 — 818.6 Investments in subsidiaries 53,200.8 14,875.6 8,994.8 — (77,071.2 ) — Intercompany — 1,403.8 1,794.6 18,446.3 (21,644.7 ) — Goodwill — 3,122.4 22,609.9 5,372.8 — 31,105.1 Other intangible assets, net — 391.3 5,665.4 3,176.1 — 9,232.8 Other assets 7.8 121.2 86.4 46.2 (40.2 ) 221.4 Total assets $ 54,333.9 $ 24,510.4 $ 39,939.6 $ 33,377.8 $ (98,756.1 ) $ 53,405.6 Claims and rebates payable $ — $ 7,463.0 $ 2,237.9 $ 268.5 $ — $ 9,969.4 Accounts payable — 842.4 27.0 3,088.0 — 3,957.4 Accrued expenses 100.1 1,084.8 313.6 1,212.2 — 2,710.7 Short-term debt and current maturities of long-term debt 85.6 — — — — 85.6 Total current liabilities 185.7 9,390.2 2,578.5 4,568.7 — 16,723.1 Long-term debt 14,061.0 336.8 502.7 — — 14,900.5 Intercompany 21,644.7 — — — (21,644.7 ) — Deferred taxes — — 1,328.6 1,208.1 (40.2 ) 2,496.5 Other liabilities — 536.0 270.4 31.0 — 837.4 Non-controlling interest — — — 5.6 — 5.6 Express Scripts stockholders’ equity 18,442.5 14,247.4 35,259.4 27,564.4 (77,071.2 ) 18,442.5 Total liabilities and stockholders’ equity $ 54,333.9 $ 24,510.4 $ 39,939.6 $ 33,377.8 $ (98,756.1 ) $ 53,405.6 Condensed Consolidating Balance Sheet (in millions) Express Scripts Holding Company Express Scripts, Medco Health Solutions, Non-Guarantors Eliminations Consolidated As of December 31, 2017 Cash and cash equivalents $ 1,031.0 $ 114.5 $ — $ 1,164.1 $ — $ 2,309.6 Receivables, net — 3,740.9 971.3 2,344.1 — 7,056.3 Other current assets — 350.7 2.1 2,238.4 — 2,591.2 Total current assets 1,031.0 4,206.1 973.4 5,746.6 — 11,957.1 Property and equipment, net — 166.1 3.2 382.0 — 551.3 Computer software, net — 640.0 — 174.9 — 814.9 Investments in subsidiaries 52,546.3 14,350.2 8,926.0 — (75,822.5 ) — Intercompany — 847.1 2,531.5 17,624.0 (21,002.6 ) — Goodwill — 3,122.4 22,609.9 5,367.4 — 31,099.7 Other intangible assets, net — 449.5 5,917.1 3,259.3 — 9,625.9 Other assets 8.2 112.6 80.3 42.7 (36.9 ) 206.9 Total assets $ 53,585.5 $ 23,894.0 $ 41,041.4 $ 32,596.9 $ (96,862.0 ) $ 54,255.8 Claims and rebates payable $ — $ 7,389.4 $ 2,574.3 $ 224.8 $ — $ 10,188.5 Accounts payable — 840.3 34.0 2,881.4 — 3,755.7 Accrued expenses 126.6 1,192.7 272.7 1,277.3 — 2,869.3 Short-term debt and current maturities of long-term debt 194.8 — 838.1 — — 1,032.9 Total current liabilities 321.4 9,422.4 3,719.1 4,383.5 — 17,846.4 Long-term debt 14,141.9 336.7 502.9 — — 14,981.5 Intercompany 21,002.6 — — — (21,002.6 ) — Deferred taxes — — 1,392.2 1,207.1 (36.9 ) 2,562.4 Other liabilities — 457.1 258.4 24.7 — 740.2 Non-controlling interest — — — 5.7 — 5.7 Express Scripts stockholders’ equity 18,119.6 13,677.8 35,168.8 26,975.9 (75,822.5 ) 18,119.6 Total liabilities and stockholders’ equity $ 53,585.5 $ 23,894.0 $ 41,041.4 $ 32,596.9 $ (96,862.0 ) $ 54,255.8
Condensed Consolidating Statement of Operations	Condensed Consolidating Statement of Operations and Comprehensive Income (in millions) Express Scripts Holding Company Express Scripts, Inc. Medco Health Solutions, Inc. Non-Guarantors Eliminations Consolidated For the three months ended March 31, 2018 Revenues $ — $ 16,908.8 $ 4,250.5 $ 15,233.8 $ (11,623.7 ) $ 24,769.4 Operating expenses — 16,824.0 4,149.7 14,457.8 (11,623.7 ) 23,807.8 Operating income — 84.8 100.8 776.0 — 961.6 Other (expense) income: Interest (expense) income and other, net (158.3 ) 6.9 8.6 0.8 — (142.0 ) Intercompany interest income (expense) 159.6 (68.6 ) (78.7 ) (12.3 ) — — Other (expense) income, net 1.3 (61.7 ) (70.1 ) (11.5 ) — (142.0 ) Income before income taxes 1.3 23.1 30.7 764.5 — 819.6 Provision for income taxes 0.3 5.0 8.9 179.5 — 193.7 Income before equity in earnings of subsidiaries 1.0 18.1 21.8 585.0 — 625.9 Equity in earnings of subsidiaries 622.2 523.3 65.1 — (1,210.6 ) — Net income 623.2 541.4 86.9 585.0 (1,210.6 ) 625.9 Less: Net income attributable to non-controlling interest — — — 2.7 — 2.7 Net income attributable to Express Scripts 623.2 541.4 86.9 582.3 (1,210.6 ) 623.2 Other comprehensive loss (2.8 ) (2.8 ) — (2.8 ) 5.6 (2.8 ) Comprehensive income attributable to Express Scripts $ 620.4 $ 538.6 $ 86.9 $ 579.5 $ (1,205.0 ) $ 620.4 For the three months ended March 31, 2017 Revenues $ — $ 9,952.9 $ 4,919.5 $ 10,876.7 $ (1,094.2 ) $ 24,654.9 Operating expenses — 9,200.7 4,545.5 10,948.3 (1,094.2 ) 23,600.3 Operating income (loss) — 752.2 374.0 (71.6 ) — 1,054.6 Other (expense) income: Interest expense and other, net (124.1 ) (3.1 ) (11.0 ) (1.2 ) — (139.4 ) Intercompany interest income (expense) 49.8 (24.9 ) — (24.9 ) — — Other expense, net (74.3 ) (28.0 ) (11.0 ) (26.1 ) — (139.4 ) Income (loss) before income taxes (74.3 ) 724.2 363.0 (97.7 ) — 915.2 Provision (benefit) for income taxes (27.3 ) 293.0 151.6 (52.4 ) — 364.9 Income (loss) before equity in earnings of subsidiaries (47.0 ) 431.2 211.4 (45.3 ) — 550.3 Equity in earnings (loss) of subsidiaries 593.3 64.8 (114.1 ) — (544.0 ) — Net income (loss) 546.3 496.0 97.3 (45.3 ) (544.0 ) 550.3 Less: Net income attributable to non-controlling interest — — — 4.0 — 4.0 Net income (loss) attributable to Express Scripts 546.3 496.0 97.3 (49.3 ) (544.0 ) 546.3 Other comprehensive income 1.2 1.2 — 1.2 (2.4 ) 1.2 Comprehensive income (loss) attributable to Express Scripts $ 547.5 $ 497.2 $ 97.3 $ (48.1 ) $ (546.4 ) $ 547.5
Condensed Consolidating Statement of Cash Flows	Condensed Consolidating Statements of Cash Flows (in millions) Express Scripts Holding Company Express Scripts, Inc. Medco Health Solutions, Inc. Non-Guarantors Eliminations Consolidated For the three months ended March 31, 2018 Net cash flows provided by (used in) operating activities $ (25.3 ) $ 674.7 $ 96.0 $ 781.6 $ (15.4 ) $ 1,511.6 Cash flows from investing activities: Capital expenditures for property and equipment and computer software — (80.2 ) — (20.2 ) — (100.4 ) Acquisition of business, net of cash acquired — — — (23.1 ) — (23.1 ) Other, net — (3.7 ) — (2.3 ) — (6.0 ) Net cash used in investing activities — (83.9 ) — (45.6 ) — (129.5 ) Cash flows from financing activities: Repayment of long-term debt — — (831.4 ) — — (831.4 ) Treasury stock acquired (420.7 ) — — — — (420.7 ) Commercial paper borrowings (repayments), net (195.0 ) — — — — (195.0 ) Net proceeds from employee stock plans 82.3 — — — — 82.3 Other, net (0.1 ) (2.8 ) — (19.7 ) 15.4 (7.2 ) Net intercompany transactions 653.1 (569.0 ) 735.4 (819.5 ) — — Net cash (used in) provided by financing activities 119.6 (571.8 ) (96.0 ) (839.2 ) 15.4 (1,372.0 ) Effect of foreign currency translation adjustment — — — (2.1 ) — (2.1 ) Net increase (decrease) in cash and cash equivalents 94.3 19.0 — (105.3 ) — 8.0 Cash and cash equivalents at beginning of period 1,031.0 114.5 — 1,164.1 — 2,309.6 Cash and cash equivalents at end of period $ 1,125.3 $ 133.5 $ — $ 1,058.8 $ — $ 2,317.6 For the three months ended March 31, 2017 Net cash flows provided by (used in) operating activities $ (79.5 ) $ 725.1 $ 429.2 $ (46.4 ) $ (28.0 ) $ 1,000.4 Cash flows from investing activities: Capital expenditures for property and equipment and computer software — (32.6 ) — (13.2 ) — (45.8 ) Other, net — (4.1 ) — 1.8 — (2.3 ) Net cash used in investing activities — (36.7 ) — (11.4 ) — (48.1 ) Cash flows from financing activities: Repayment of long-term debt (37.5 ) — — — — (37.5 ) Treasury stock acquired (837.4 ) — — — — (837.4 ) Net proceeds from employee stock plans 14.5 — — — — 14.5 Other, net — — — (34.1 ) 28.0 (6.1 ) Net intercompany transactions 1,767.2 (1,123.5 ) (433.6 ) (210.1 ) — — Net cash (used in) provided by financing activities 906.8 (1,123.5 ) (433.6 ) (244.2 ) 28.0 (866.5 ) Effect of foreign currency translation adjustment — — — 0.8 — 0.8 Net increase (decrease) in cash and cash equivalents 827.3 (435.1 ) (4.4 ) (301.2 ) — 86.6 Cash and cash equivalents at beginning of period 583.5 1,234.2 4.4 1,255.1 — 3,077.2 Cash and cash equivalents at end of period $ 1,410.8 $ 799.1 $ — $ 953.9 $ — $ 3,163.8

Summary of significant accoun34

Summary of significant accounting policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Mar. 08, 2018	Mar. 31, 2018	Mar. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues		$ 24,769.4	$ 24,654.9
Cost of revenues		22,890	22,782.2
Express Scripts Holding Company
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percentage of business acquired	36.00%
Express Scripts Holding Company | Cigna
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total consideration	$ 67,000
Liabilities assumed	$ 15,000
Business combination share conversion rate (per share)	$ 0.2434
Business combination per share consideration	$ 48.75
Percentage of business acquired	64.00%
Product revenues
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues		23,821.5	$ 24,245
Product revenues | Difference between revenue guidance in effect before and after Topic 606 | ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenues		798.8
Cost of revenues		$ 798.8

Revenue - Schedule of Disaggreg

Revenue - Schedule of Disaggregation of Revenue (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 24,769.4	$ 24,654.9
Network revenues
Disaggregation of Revenue [Line Items]
Revenues	12,262.5	12,406.4
Home delivery and specialty revenues
Disaggregation of Revenue [Line Items]
Revenues	10,602.7	10,828.4
Other revenues
Disaggregation of Revenue [Line Items]
Revenues	956.3	1,010.2
Product revenues
Disaggregation of Revenue [Line Items]
Revenues	23,821.5	24,245
Service revenues
Disaggregation of Revenue [Line Items]
Revenues	947.9	409.9
PBM
Disaggregation of Revenue [Line Items]
Revenues	23,172.5	23,561.3
PBM | Network revenues
Disaggregation of Revenue [Line Items]
Revenues	12,262.5	12,406.4
PBM | Home delivery and specialty revenues
Disaggregation of Revenue [Line Items]
Revenues	10,602.7	10,828.4
PBM | Other revenues
Disaggregation of Revenue [Line Items]
Revenues	0	0
PBM | Product revenues
Disaggregation of Revenue [Line Items]
Revenues	22,865.2	23,234.8
PBM | Service revenues
Disaggregation of Revenue [Line Items]
Revenues	307.3	326.5
Other Business Operations
Disaggregation of Revenue [Line Items]
Revenues	1,596.9	1,093.6
Other Business Operations | Network revenues
Disaggregation of Revenue [Line Items]
Revenues	0	0
Other Business Operations | Home delivery and specialty revenues
Disaggregation of Revenue [Line Items]
Revenues	0	0
Other Business Operations | Other revenues
Disaggregation of Revenue [Line Items]
Revenues	956.3	1,010.2
Other Business Operations | Product revenues
Disaggregation of Revenue [Line Items]
Revenues	956.3	1,010.2
Other Business Operations | Service revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 640.6	$ 83.4

Revenue Revenue - Schedule of D

Revenue Revenue - Schedule of Disaggregation of Revenue (Footnotes) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 24,769.4	$ 24,654.9
Cost of revenues	22,890	22,782.2
Product
Disaggregation of Revenue [Line Items]
Revenues	23,821.5	24,245
PBM
Disaggregation of Revenue [Line Items]
Revenues	23,172.5	23,561.3
PBM | Retail pharmacy co-payment
Disaggregation of Revenue [Line Items]
Revenues	2,492.4	2,466.3
PBM | Product
Disaggregation of Revenue [Line Items]
Revenues	22,865.2	$ 23,234.8
ASU 2014-09 | Difference between revenue guidance in effect before and after Topic 606 | Product
Disaggregation of Revenue [Line Items]
Revenues	798.8
Cost of revenues	$ 798.8

Revenue - Additional Informatio

Revenue - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract With Customer, Contract Term	3 years
Contract with customer, liability	$ 885.1	$ 785.6
Contract with customer, asset	$ 0	$ 0
PBM
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract With Customer, Contract Term	3 years
Payment terms	30 days
Medical benefit management
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract With Customer, Contract Term	3 years
Payment terms	30 days
Specialty distribution
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contract With Customer, Contract Term	30 days

Fair value measurements - Addit

Fair value measurements - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Senior notes | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	$ 12,996.7	$ 14,215.7
Recurring basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Average maturity period of investment in AAA-rated money market mutual funds, days	90 days

Receivables, net (Details)

Receivables, net (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade receivables, net	$ 3,846.8	$ 4,101.6
Pharmaceutical manufacturers receivables, net	2,565.7	2,580.8
Other receivables	381.1	373.9
Total receivables, net	6,793.6	7,056.3
Total reserves and allowances for trade receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Valuation allowances and reserves	455.5	466.6
Contractual allowances for certain rebates receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Valuation allowances and reserves	$ 423.3	$ 414.1

Acquisition - Additional Inform

Acquisition - Additional Information (Detail) - USD ($) $ in Millions	Dec. 15, 2017	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Business Acquisition [Line Items]
Revenues		$ 24,769.4	$ 24,654.9
Net loss		(623.2)	$ (546.3)
Goodwill		31,105.1		$ 31,099.7
eviCore
Business Acquisition [Line Items]
Percentage of business acquired	100.00%
Total consideration	$ 3,600
Future contingent arrangement with certain equity holders	$ 81.1
Percentage paid on second and third anniversaries	50.00%
Period for post combination services	3 years
Revenues		640.7
Net loss		6.1
Current contingent expense		$ 10.4
Goodwill	$ 1,703.3
Goodwill expected to be tax deductible	$ 397

Acquisition - Pro Forma Informa

Acquisition - Pro Forma Information (Detail) - eviCore $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)$ / shares
Business Acquisition [Line Items]
Total revenues | $	$ 25,149.9
Net income attributable to Express Scripts | $	$ 527.5
Basic earnings per share | $ / shares	$ 0.88
Diluted earnings per share | $ / shares	$ 0.87

Acquisition - Estimated Fair Va

Acquisition - Estimated Fair Values of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Dec. 15, 2017
Business Acquisition [Line Items]
Goodwill	$ 31,105.1	$ 31,099.7
eviCore
Business Acquisition [Line Items]
Current assets			$ 494.7
Property and equipment			15.2
Computer software			89.7
Goodwill			1,703.3
Acquired intangible assets			2,328.8
Other noncurrent assets			2.9
Current liabilities			(387.4)
Deferred income taxes			(592.3)
Other noncurrent liabilities			(9)
Net assets acquired and liabilities assumed			$ 3,645.9

Acquisition - Acquired Intangib

Acquisition - Acquired Intangible Assets (Detail) - eviCore $ in Millions	Dec. 15, 2017USD ($)
Business Acquisition [Line Items]
Acquired intangible assets	$ 2,328.8
Weighted-average amortization period (in years)	19 years 9 months
Trade name
Business Acquisition [Line Items]
Acquired intangible assets	$ 56.1
Weighted-average amortization period (in years)	10 years
Customer relationships
Business Acquisition [Line Items]
Acquired intangible assets	$ 2,272.7
Weighted-average amortization period (in years)	20 years

Goodwill and other intangible44

Goodwill and other intangible assets - Summary of Goodwill and Other Intangible Assets (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Gross Carrying Amount	$ 31,211.9	$ 31,206.7
Accumulated Amortization	(106.8)	(107)
Net Carrying Amount	31,105.1	31,099.7
Finite-Lived Intangible Assets, Gross	20,102	20,140.3
Accumulated Amortization	(10,869.2)	(10,514.4)
Net Carrying Amount	9,232.8	9,625.9
PBM
Goodwill [Line Items]
Gross Carrying Amount	29,434.2	29,434.9
Accumulated Amortization	(106.8)	(107)
Net Carrying Amount	29,327.4	29,327.9
Finite-Lived Intangible Assets, Gross	17,762.8	17,811.5
Accumulated Amortization	(10,819.8)	(10,507.2)
Net Carrying Amount	6,943	7,304.3
PBM | Customer contracts
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	17,530.3	17,579
Accumulated Amortization	(10,685.2)	(10,378.4)
Net Carrying Amount	6,845.1	7,200.6
PBM | Trade names
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	232.5	232.5
Accumulated Amortization	(134.6)	(128.8)
Net Carrying Amount	97.9	103.7
Other Business Operations
Goodwill [Line Items]
Gross Carrying Amount	1,777.7	1,771.8
Accumulated Amortization	0	0
Net Carrying Amount	1,777.7	1,771.8
Finite-Lived Intangible Assets, Gross	2,339.2	2,328.8
Accumulated Amortization	(49.4)	(7.2)
Net Carrying Amount	2,289.8	2,321.6
Other Business Operations | Trade names
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	56.7	56.1
Accumulated Amortization	(1.8)	(0.2)
Net Carrying Amount	54.9	55.9
Other Business Operations | Customer relationships
Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	2,282.5	2,272.7
Accumulated Amortization	(47.6)	(7)
Net Carrying Amount	$ 2,234.9	$ 2,265.7

Goodwill and other intangible45

Goodwill and other intangible assets - Summary of Change in Net Carrying Value of Goodwill by Business Segment (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Goodwill [Roll Forward]
Balance at December 31, 2017	$ 31,099.7
Acquisitions	5.9
Foreign currency translation	(0.5)
Balance at March 31, 2018	31,105.1
PBM
Goodwill [Roll Forward]
Balance at December 31, 2017	29,327.9
Acquisitions	0
Foreign currency translation	(0.5)
Balance at March 31, 2018	29,327.4
Other Business Operations
Goodwill [Roll Forward]
Balance at December 31, 2017	1,771.8
Acquisitions	5.9
Foreign currency translation	0
Balance at March 31, 2018	$ 1,777.7

Goodwill and other intangible46

Goodwill and other intangible assets - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)segment	Mar. 31, 2017USD ($)
Goodwill [Line Items]
Number of reportable segments | segment	2
Amortization of intangible assets	$ 403.5	$ 362.4
Weighted average amortization period of intangible assets subject to amortization	16 years
Customer-related intangible assets | Minimum
Goodwill [Line Items]
Weighted average amortization period of intangible assets subject to amortization	10 years
Customer-related intangible assets | Maximum
Goodwill [Line Items]
Weighted average amortization period of intangible assets subject to amortization	20 years
Trade names | Minimum
Goodwill [Line Items]
Weighted average amortization period of intangible assets subject to amortization	6 years
Trade names | Maximum
Goodwill [Line Items]
Weighted average amortization period of intangible assets subject to amortization	10 years
Anthem | Customer contracts
Goodwill [Line Items]
Amortization of intangible assets	$ 55.4	$ 55.4
Period of contract	10 years

Earnings per share - Schedule o

Earnings per share - Schedule of Weighted Average Number of Shares (Detail) - shares shares in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Weighted-average number of common shares outstanding during the period - basic (shares)	562.8	601
Dilutive common stock equivalents:
Outstanding stock options, restricted stock units and executive deferred compensation	4.3	4.1
Weighted-average number of common shares outstanding during the period - diluted (shares)	567.1	605.1

Earnings per share - Schedule48

Earnings per share - Schedule of Weighted Average Number of Shares (Footnotes) (Detail) - shares shares in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Antidilutive shares excluded from basic and diluted EPS calculations	4.5	9

Financing - Summary of Company'

Financing - Summary of Company's Debt, Net of Unamortized Discounts and Premiums (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total debt	$ 14,986,100,000	$ 16,014,400,000
Short-term debt and current maturities of long-term debt	85,600,000	1,032,900,000
Total long-term debt, excluding current maturities	14,900,500,000	14,981,500,000
Commercial paper program
Debt Instrument [Line Items]
Commercial paper	0	194,800,000
Senior notes
Debt Instrument [Line Items]
Long-term debt	12,840,100,000	13,674,100,000
Senior notes | $1,200.0 million, 7.125% senior notes due March 2018
Debt Instrument [Line Items]
Long-term debt	0	838,100,000
Long-term debt, current maturities	$ 0	838,100,000
Interest rate on debt instrument	7.125%
Margin over interest rate	0.50%
Debt instrument, principal	$ 1,200,000,000
Senior notes | $1,000.0 million, 2.250% senior notes due June 2019
Debt Instrument [Line Items]
Long-term debt	$ 997,600,000	997,100,000
Interest rate on debt instrument	2.25%
Margin over interest rate	0.15%
Debt instrument, principal	$ 1,000,000,000
Senior notes | $500.0 million, 7.250% senior notes due June 2019
Debt Instrument [Line Items]
Long-term debt	$ 336,800,000	336,700,000
Interest rate on debt instrument	7.25%
Margin over interest rate	0.50%
Debt instrument, principal	$ 500,000,000
Senior notes | $500.0 million, 4.125% senior notes due September 2020
Debt Instrument [Line Items]
Long-term debt	$ 502,700,000	502,900,000
Interest rate on debt instrument	4.125%
Margin over interest rate	0.25%
Debt instrument, principal	$ 500,000,000
Senior notes | $500.0 million, 2.600% senior notes due November 2020
Debt Instrument [Line Items]
Long-term debt	$ 497,100,000	496,900,000
Interest rate on debt instrument	2.60%
Margin over interest rate	0.15%
Debt instrument, principal	$ 500,000,000
Senior notes | $400.0 million, floating rate senior notes due November 2020
Debt Instrument [Line Items]
Long-term debt	397,800,000	397,600,000
Debt instrument, principal	400,000,000
Senior notes | $500.0 million, 3.300% senior notes due February 2021
Debt Instrument [Line Items]
Long-term debt	$ 497,100,000	496,900,000
Interest rate on debt instrument	3.30%
Margin over interest rate	0.35%
Debt instrument, principal	$ 500,000,000
Senior notes | $1,250.0 million, 4.750% senior notes due November 2021
Debt Instrument [Line Items]
Long-term debt	$ 1,242,100,000	1,241,600,000
Interest rate on debt instrument	4.75%
Margin over interest rate	0.45%
Debt instrument, principal	$ 1,250,000,000
Senior notes | $1,000.0 million, 3.900% senior notes due February 2022
Debt Instrument [Line Items]
Long-term debt	$ 987,800,000	987,000,000
Interest rate on debt instrument	3.90%
Margin over interest rate	0.40%
Debt instrument, principal	$ 1,000,000,000
Senior notes | $500.0 million, 3.050% senior notes due November 2022
Debt Instrument [Line Items]
Long-term debt	$ 495,400,000	495,200,000
Interest rate on debt instrument	3.05%
Margin over interest rate	0.15%
Debt instrument, principal	$ 500,000,000
Senior notes | $1,000.0 million, 3.000% senior notes due July 2023
Debt Instrument [Line Items]
Long-term debt	$ 993,900,000	993,600,000
Interest rate on debt instrument	3.00%
Margin over interest rate	0.25%
Debt instrument, principal	$ 1,000,000,000
Senior notes | $1,000.0 million, 3.500% senior notes due June 2024
Debt Instrument [Line Items]
Long-term debt	$ 990,200,000	989,800,000
Interest rate on debt instrument	3.50%
Margin over interest rate	0.20%
Debt instrument, principal	$ 1,000,000,000
Senior notes | $1,500.0 million, 4.500% senior notes due February 2026
Debt Instrument [Line Items]
Long-term debt	$ 1,483,600,000	1,483,100,000
Interest rate on debt instrument	4.50%
Margin over interest rate	0.45%
Debt instrument, principal	$ 1,500,000,000
Senior notes | $1,500.0 million, 3.400% senior notes due March 2027
Debt Instrument [Line Items]
Long-term debt	$ 1,490,100,000	1,489,800,000
Interest rate on debt instrument	3.40%
Margin over interest rate	0.30%
Debt instrument, principal	$ 1,500,000,000
Senior notes | $700.0 million, 6.125% senior notes due November 2041
Debt Instrument [Line Items]
Long-term debt	$ 444,200,000	444,200,000
Interest rate on debt instrument	6.125%
Margin over interest rate	0.50%
Debt instrument, principal	$ 700,000,000
Senior notes | $1,500.0 million, 4.800% senior notes due July 2046
Debt Instrument [Line Items]
Long-term debt	$ 1,483,700,000	1,483,600,000
Interest rate on debt instrument	4.80%
Margin over interest rate	0.40%
Debt instrument, principal	$ 1,500,000,000
Notes payable to banks | $3,000.0 million, term loan due April 2020
Debt Instrument [Line Items]
Long-term debt	2,146,000,000	2,145,500,000
Long-term debt, current maturities	85,600,000	$ 0
Credit facility, maximum capacity	3,000,000,000
Commercial paper program | Commercial paper program
Debt Instrument [Line Items]
Credit facility, maximum capacity	$ 3,500,000,000

Financing - Summary of Compan50

Financing - Summary of Company's Debt, Net of Unamortized Discounts and Premiums (Footnotes) (Detail) - USD ($) $ in Millions	2 Months Ended		3 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Mar. 31, 2018
Debt Instrument [Line Items]
Senior note redemption assumptions, period days in year			360 days
Senior note redemption assumptions, period months in year			12 months
Senior note redemption assumptions, period days in month			30 days
Senior note redemption assumptions, interest payment commencement			6 months
Senior notes
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage			100.00%
Senior notes | $400.0 million, floating rate senior notes due November 2020
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage			100.00%
Long-term debt, average interest rate	2.23%		2.40%
Notes payable to banks | 2015 five-year term loan
Debt Instrument [Line Items]
Average interest rate	2.30%	2.30%	2.76%
Commercial paper program | Commercial paper program
Debt Instrument [Line Items]
Short-term debt, average outstanding amount		$ 220.1	$ 129.4
Short-term debt, weighted average interest rate		1.49%	1.83%

Financing - Additional Informat

Financing - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018USD ($)	Feb. 28, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Number of lines of credit	1
Commercial paper program
Debt Instrument [Line Items]
Commercial paper	$ 0		$ 194,800,000
Revolving credit facility | 2022 revolving facility
Debt Instrument [Line Items]
Credit facility, maximum capacity	3,500,000,000
Line of credit facility, amount outstanding	0
Revolving credit facility | 2015 credit facility
Debt Instrument [Line Items]
Credit facility, maximum capacity	150,000,000
Line of credit facility, amount outstanding	0
Revolving credit facility | 2017 credit facility
Debt Instrument [Line Items]
Credit facility, maximum capacity		$ 130,000,000
Line of credit facility, amount outstanding	0
Notes payable to banks | 2015 five-year term loan
Debt Instrument [Line Items]
Credit facility, maximum capacity	3,000,000,000
Current maturities, excluding unamortized financing costs	$ 87,500,000
Minimum | Revolving credit facility | 2015 revolving facility
Debt Instrument [Line Items]
Commitment fee on the unused portion of the revolving credit facility	0.07%
Maximum | Revolving credit facility | 2015 revolving facility
Debt Instrument [Line Items]
Commitment fee on the unused portion of the revolving credit facility	0.20%
LIBOR | Minimum | Revolving credit facility | 2015 revolving facility
Debt Instrument [Line Items]
Margin over interest rate	0.805%
LIBOR | Minimum | Notes payable to banks | 2015 five-year term loan
Debt Instrument [Line Items]
Margin over interest rate	1.00%
LIBOR | Maximum | Revolving credit facility | 2015 revolving facility
Debt Instrument [Line Items]
Margin over interest rate	1.30%
LIBOR | Maximum | Notes payable to banks | 2015 five-year term loan
Debt Instrument [Line Items]
Margin over interest rate	1.50%
Adjusted base rate | Minimum | Revolving credit facility | 2015 revolving facility
Debt Instrument [Line Items]
Margin over interest rate	0.00%
Adjusted base rate | Minimum | Notes payable to banks | 2015 five-year term loan
Debt Instrument [Line Items]
Margin over interest rate	0.00%
Adjusted base rate | Maximum | Revolving credit facility | 2015 revolving facility
Debt Instrument [Line Items]
Margin over interest rate	0.30%
Adjusted base rate | Maximum | Notes payable to banks | 2015 five-year term loan
Debt Instrument [Line Items]
Margin over interest rate	0.50%
Commercial paper program | Commercial paper program
Debt Instrument [Line Items]
Credit facility, maximum capacity	$ 3,500,000,000

Income taxes - Additional Infor

Income taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Effective tax rate	23.70%	40.00%
Discrete tax charges	$ 1.2	$ 29.9

Common stock - Additional Infor

Common stock - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Treasury stock, shares, acquired	5.4	13.3
Treasury stock, value, acquired	$ 411.3
Stock Repurchase Program, remaining number of shares authorized to be repurchased	72.9
Treasury Stock
Treasury stock, value, acquired	$ 411.3	$ 902.6

Stock-based compensation plan54

Stock-based compensation plans - Additional Information (Detail) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares	Mar. 31, 2017USD ($)	May 04, 2016shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense | $	$ 32.3	$ 27.1
Unamortized stock-based compensation, stock options | $	$ 20.6
Number of stock options granted (shares)	800,000
Weighted-average grant date fair value granted (usd per share) | $ / shares	$ 16.27
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term of awards granted	10 years
Award vesting period	3 years
Restricted stock units and performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unamortized stock-based compensation, restricted stock units and performance shares | $	$ 144.9
Number of restricted stock units and performance shares granted (shares)	1,600,000
Weighted-average fair market value of restricted stock units and performance shares granted (shares) | $ / shares	$ 73.77
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Maximum multiplier used to calculate value of performance shares	2.5
Performance shares granted to certain officers exceeding certain performance metrics	100,000
2016 LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares available for grant (shares)	33,000,000
Maximum term of awards granted	10 years
2011 LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for employee benefit plans (shares)			0
Accredo Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for employee benefit plans (shares)			0
2000 LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for employee benefit plans (shares)			0
2002 SIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for employee benefit plans (shares)			0

Stock-based compensation plan55

Stock-based compensation plans - Weighted Average Assumptions to Value Options Granted (Detail)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of option	3 years	3 years
Risk-free interest rate	2.40%	1.60%
Expected volatility of stock	21.00%	22.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of option	5 years	5 years
Risk-free interest rate	2.70%	2.10%
Expected volatility of stock	24.00%	23.00%

Commitments and contingencies (

Commitments and contingencies (Detail) - Anthem, Inc. v. Express Scripts, Inc. - Pending litigation	Mar. 21, 2016USD ($)
Pricing concessions over remaining term of contract
Loss Contingencies [Line Items]
Loss contingency, damages sought	$ 13,000,000,000
Pricing concessions for 1 year following contract termination
Loss Contingencies [Line Items]
Loss contingency, damages sought	1,800,000,000
Damages for service issues
Loss Contingencies [Line Items]
Loss contingency, damages sought	$ 150,000,000

Enterprise value initiative - A

Enterprise value initiative - Additional Information (Detail) - USD ($)	3 Months Ended		7 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Liabilities	$ 34,957,500,000		$ 34,957,500,000	$ 36,130,500,000
Enterprise Value Initiative
Restructuring Cost and Reserve [Line Items]
Total EVI costs	17,700,000	$ 0	60,500,000
Capitalized computer software, gross	4,800,000		4,800,000
Liabilities	0		0	$ 0
Enterprise Value Initiative | Cost of revenues
Restructuring Cost and Reserve [Line Items]
Total EVI costs	5,300,000
Enterprise Value Initiative | Selling, general and administrative expenses
Restructuring Cost and Reserve [Line Items]
Total EVI costs	12,400,000
Minimum | Enterprise Value Initiative
Restructuring Cost and Reserve [Line Items]
Estimated costs	600,000,000		600,000,000
Maximum | Enterprise Value Initiative
Restructuring Cost and Reserve [Line Items]
Estimated costs	$ 650,000,000		$ 650,000,000

Enterprise value initiative - C

Enterprise value initiative - Components of Incremental Cost (Detail) - Enterprise Value Initiative - USD ($) $ in Millions	3 Months Ended		7 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Consulting and temporary labor	$ 11.6
Severance and related benefit costs	3.6
Accelerated depreciation	0.4
Site closures	0.8
Technology	1.3
Total EVI costs	$ 17.7	$ 0	$ 60.5

Segment information - Reportabl

Segment information - Reportable Segments Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 24,769.4	$ 24,654.9
Depreciation and amortization expense	498.8	445.6
Operating income	961.6	1,054.6
Interest income and other	12	6.3
Interest expense and other	(154)	(145.7)
Income before income taxes	819.6	915.2
Capital expenditures	100.4	45.8
PBM
Segment Reporting Information [Line Items]
Revenues	23,172.5	23,561.3
Depreciation and amortization expense	446.3	439.6
Operating income	929.4	1,043.3
Capital expenditures	91.9	41.6
Other Business Operations
Segment Reporting Information [Line Items]
Revenues	1,596.9	1,093.6
Depreciation and amortization expense	52.5	6
Operating income	32.2	11.3
Capital expenditures	8.5	4.2
Product revenues
Segment Reporting Information [Line Items]
Revenues	23,821.5	24,245
Product revenues | PBM
Segment Reporting Information [Line Items]
Revenues	22,865.2	23,234.8
Product revenues | Other Business Operations
Segment Reporting Information [Line Items]
Revenues	956.3	1,010.2
Service revenues
Segment Reporting Information [Line Items]
Revenues	947.9	409.9
Service revenues | PBM
Segment Reporting Information [Line Items]
Revenues	307.3	326.5
Service revenues | Other Business Operations
Segment Reporting Information [Line Items]
Revenues	$ 640.6	$ 83.4

Segment information - Reporta60

Segment information - Reportable Segments Information (Footnotes) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Revenues	$ 24,769.4	$ 24,654.9
PBM
Segment Reporting Information [Line Items]
Revenues	23,172.5	23,561.3
Retail pharmacy co-payment | PBM
Segment Reporting Information [Line Items]
Revenues	2,492.4	2,466.3
Product revenues
Segment Reporting Information [Line Items]
Revenues	23,821.5	24,245
Product revenues | Difference between revenue guidance in effect before and after Topic 606 | ASU 2014-09
Segment Reporting Information [Line Items]
Revenues	798.8
Product revenues | PBM
Segment Reporting Information [Line Items]
Revenues	$ 22,865.2	$ 23,234.8

Segment information - Additiona

Segment information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018segment
Segment Reporting Information [Line Items]
Number of reportable segments	2
Other Business Operations
Segment Reporting Information [Line Items]
Number of operating segments in Other Business Operations reportable segment	2
Anthem | Customer concentration risk | Revenues
Segment Reporting Information [Line Items]
Concentration risk, percentage of total revenue	18.00%
Department Of Defense (DoD) | Customer concentration risk | Revenues
Segment Reporting Information [Line Items]
Concentration risk, percentage of total revenue	12.00%

Condensed consolidating finan62

Condensed consolidating financial information - Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 2,317.6	$ 2,309.6	$ 3,163.8	$ 3,077.2
Receivables, net	6,793.6	7,056.3
Other current assets	2,363.6	2,591.2
Total current assets	11,474.8	11,957.1
Property and equipment, net	552.9	551.3
Computer software, net	818.6	814.9
Investments in subsidiaries	0	0
Intercompany	0	0
Goodwill	31,105.1	31,099.7
Other intangible assets, net	9,232.8	9,625.9
Other assets	221.4	206.9
Total assets	53,405.6	54,255.8
Claims and rebates payable	9,969.4	10,188.5
Accounts payable	3,957.4	3,755.7
Accrued expenses	2,710.7	2,869.3
Short-term debt and current maturities of long-term debt	85.6	1,032.9
Total current liabilities	16,723.1	17,846.4
Long-term debt	14,900.5	14,981.5
Intercompany	0	0
Deferred taxes	2,496.5	2,562.4
Other liabilities	837.4	740.2
Non-controlling interest	5.6	5.7
Total Express Scripts stockholders' equity	18,442.5	18,119.6
Total liabilities and stockholders' equity	53,405.6	54,255.8
Eliminations
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Receivables, net	0	0
Other current assets	0	0
Total current assets	0	0
Property and equipment, net	0	0
Computer software, net	0	0
Investments in subsidiaries	(77,071.2)	(75,822.5)
Intercompany	(21,644.7)	(21,002.6)
Goodwill	0	0
Other intangible assets, net	0	0
Other assets	(40.2)	(36.9)
Total assets	(98,756.1)	(96,862)
Claims and rebates payable	0	0
Accounts payable	0	0
Accrued expenses	0	0
Short-term debt and current maturities of long-term debt	0	0
Total current liabilities	0	0
Long-term debt	0	0
Intercompany	(21,644.7)	(21,002.6)
Deferred taxes	(40.2)	(36.9)
Other liabilities	0	0
Non-controlling interest	0	0
Total Express Scripts stockholders' equity	(77,071.2)	(75,822.5)
Total liabilities and stockholders' equity	(98,756.1)	(96,862)
Express Scripts, Inc.
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	133.5	114.5	799.1	1,234.2
Receivables, net	3,435.2	3,740.9
Other current assets	212.5	350.7
Total current assets	3,781.2	4,206.1
Property and equipment, net	173.7	166.1
Computer software, net	641.2	640
Investments in subsidiaries	14,875.6	14,350.2
Intercompany	1,403.8	847.1
Goodwill	3,122.4	3,122.4
Other intangible assets, net	391.3	449.5
Other assets	121.2	112.6
Total assets	24,510.4	23,894
Claims and rebates payable	7,463	7,389.4
Accounts payable	842.4	840.3
Accrued expenses	1,084.8	1,192.7
Short-term debt and current maturities of long-term debt	0	0
Total current liabilities	9,390.2	9,422.4
Long-term debt	336.8	336.7
Intercompany	0	0
Deferred taxes	0	0
Other liabilities	536	457.1
Non-controlling interest	0	0
Total Express Scripts stockholders' equity	14,247.4	13,677.8
Total liabilities and stockholders' equity	24,510.4	23,894
Medco Health Solutions, Inc.
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	4.4
Receivables, net	785.2	971.3
Other current assets	0.1	2.1
Total current assets	785.3	973.4
Property and equipment, net	3.2	3.2
Computer software, net	0	0
Investments in subsidiaries	8,994.8	8,926
Intercompany	1,794.6	2,531.5
Goodwill	22,609.9	22,609.9
Other intangible assets, net	5,665.4	5,917.1
Other assets	86.4	80.3
Total assets	39,939.6	41,041.4
Claims and rebates payable	2,237.9	2,574.3
Accounts payable	27	34
Accrued expenses	313.6	272.7
Short-term debt and current maturities of long-term debt	0	838.1
Total current liabilities	2,578.5	3,719.1
Long-term debt	502.7	502.9
Intercompany	0	0
Deferred taxes	1,328.6	1,392.2
Other liabilities	270.4	258.4
Non-controlling interest	0	0
Total Express Scripts stockholders' equity	35,259.4	35,168.8
Total liabilities and stockholders' equity	39,939.6	41,041.4
Express Scripts Holding Company
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	1,125.3	1,031	1,410.8	583.5
Receivables, net	0	0
Other current assets	0	0
Total current assets	1,125.3	1,031
Property and equipment, net	0	0
Computer software, net	0	0
Investments in subsidiaries	53,200.8	52,546.3
Intercompany	0	0
Goodwill	0	0
Other intangible assets, net	0	0
Other assets	7.8	8.2
Total assets	54,333.9	53,585.5
Claims and rebates payable	0	0
Accounts payable	0	0
Accrued expenses	100.1	126.6
Short-term debt and current maturities of long-term debt	85.6	194.8
Total current liabilities	185.7	321.4
Long-term debt	14,061	14,141.9
Intercompany	21,644.7	21,002.6
Deferred taxes	0	0
Other liabilities	0	0
Non-controlling interest	0	0
Total Express Scripts stockholders' equity	18,442.5	18,119.6
Total liabilities and stockholders' equity	54,333.9	53,585.5
Non-Guarantors
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	1,058.8	1,164.1	$ 953.9	$ 1,255.1
Receivables, net	2,573.2	2,344.1
Other current assets	2,151	2,238.4
Total current assets	5,783	5,746.6
Property and equipment, net	376	382
Computer software, net	177.4	174.9
Investments in subsidiaries	0	0
Intercompany	18,446.3	17,624
Goodwill	5,372.8	5,367.4
Other intangible assets, net	3,176.1	3,259.3
Other assets	46.2	42.7
Total assets	33,377.8	32,596.9
Claims and rebates payable	268.5	224.8
Accounts payable	3,088	2,881.4
Accrued expenses	1,212.2	1,277.3
Short-term debt and current maturities of long-term debt	0	0
Total current liabilities	4,568.7	4,383.5
Long-term debt	0	0
Intercompany	0	0
Deferred taxes	1,208.1	1,207.1
Other liabilities	31	24.7
Non-controlling interest	5.6	5.7
Total Express Scripts stockholders' equity	27,564.4	26,975.9
Total liabilities and stockholders' equity	$ 33,377.8	$ 32,596.9

Condensed consolidating finan63

Condensed consolidating financial information - Condensed Consolidating Statement of Operations and Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Revenues	$ 24,769.4	$ 24,654.9
Operating expenses	23,807.8	23,600.3
Operating income	961.6	1,054.6
Interest (expense) income and other, net	(142)	(139.4)
Intercompany interest income (expense)	0	0
Other (expense) income, net	(142)	(139.4)
Income (loss) before income taxes	819.6	915.2
Provision (benefit) for income taxes	193.7	364.9
Income (loss) before equity in earnings of subsidiaries	625.9	550.3
Equity in earnings (loss) of subsidiaries	0	0
Net income	625.9	550.3
Less: Net income attributable to non-controlling interest	2.7	4
Net income attributable to Express Scripts	623.2	546.3
Other comprehensive income (loss)	(2.8)	1.2
Comprehensive income attributable to Express Scripts	620.4	547.5
Eliminations
Condensed Financial Statements, Captions [Line Items]
Revenues	(11,623.7)	(1,094.2)
Operating expenses	(11,623.7)	(1,094.2)
Operating income	0	0
Interest (expense) income and other, net	0	0
Intercompany interest income (expense)	0	0
Other (expense) income, net	0	0
Income (loss) before income taxes	0	0
Provision (benefit) for income taxes	0	0
Income (loss) before equity in earnings of subsidiaries	0	0
Equity in earnings (loss) of subsidiaries	(1,210.6)	(544)
Net income	(1,210.6)	(544)
Less: Net income attributable to non-controlling interest	0	0
Net income attributable to Express Scripts	(1,210.6)	(544)
Other comprehensive income (loss)	5.6	(2.4)
Comprehensive income attributable to Express Scripts	(1,205)	(546.4)
Express Scripts, Inc.
Condensed Financial Statements, Captions [Line Items]
Revenues	16,908.8	9,952.9
Operating expenses	16,824	9,200.7
Operating income	84.8	752.2
Interest (expense) income and other, net	6.9	(3.1)
Intercompany interest income (expense)	(68.6)	(24.9)
Other (expense) income, net	(61.7)	(28)
Income (loss) before income taxes	23.1	724.2
Provision (benefit) for income taxes	5	293
Income (loss) before equity in earnings of subsidiaries	18.1	431.2
Equity in earnings (loss) of subsidiaries	523.3	64.8
Net income	541.4	496
Less: Net income attributable to non-controlling interest	0	0
Net income attributable to Express Scripts	541.4	496
Other comprehensive income (loss)	(2.8)	1.2
Comprehensive income attributable to Express Scripts	538.6	497.2
Medco Health Solutions, Inc.
Condensed Financial Statements, Captions [Line Items]
Revenues	4,250.5	4,919.5
Operating expenses	4,149.7	4,545.5
Operating income	100.8	374
Interest (expense) income and other, net	8.6	(11)
Intercompany interest income (expense)	(78.7)	0
Other (expense) income, net	(70.1)	(11)
Income (loss) before income taxes	30.7	363
Provision (benefit) for income taxes	8.9	151.6
Income (loss) before equity in earnings of subsidiaries	21.8	211.4
Equity in earnings (loss) of subsidiaries	65.1	(114.1)
Net income	86.9	97.3
Less: Net income attributable to non-controlling interest	0	0
Net income attributable to Express Scripts	86.9	97.3
Other comprehensive income (loss)	0	0
Comprehensive income attributable to Express Scripts	86.9	97.3
Express Scripts Holding Company
Condensed Financial Statements, Captions [Line Items]
Revenues	0	0
Operating expenses	0	0
Operating income	0	0
Interest (expense) income and other, net	(158.3)	(124.1)
Intercompany interest income (expense)	159.6	49.8
Other (expense) income, net	1.3	(74.3)
Income (loss) before income taxes	1.3	(74.3)
Provision (benefit) for income taxes	0.3	(27.3)
Income (loss) before equity in earnings of subsidiaries	1	(47)
Equity in earnings (loss) of subsidiaries	622.2	593.3
Net income	623.2	546.3
Less: Net income attributable to non-controlling interest	0	0
Net income attributable to Express Scripts	623.2	546.3
Other comprehensive income (loss)	(2.8)	1.2
Comprehensive income attributable to Express Scripts	620.4	547.5
Non-Guarantors
Condensed Financial Statements, Captions [Line Items]
Revenues	15,233.8	10,876.7
Operating expenses	14,457.8	10,948.3
Operating income	776	(71.6)
Interest (expense) income and other, net	0.8	(1.2)
Intercompany interest income (expense)	(12.3)	(24.9)
Other (expense) income, net	(11.5)	(26.1)
Income (loss) before income taxes	764.5	(97.7)
Provision (benefit) for income taxes	179.5	(52.4)
Income (loss) before equity in earnings of subsidiaries	585	(45.3)
Equity in earnings (loss) of subsidiaries	0	0
Net income	585	(45.3)
Less: Net income attributable to non-controlling interest	2.7	4
Net income attributable to Express Scripts	582.3	(49.3)
Other comprehensive income (loss)	(2.8)	1.2
Comprehensive income attributable to Express Scripts	$ 579.5	$ (48.1)

Condensed consolidating finan64

Condensed consolidating financial information - Condensed Consolidating Statement of Cash Flows (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	$ 1,511.6	$ 1,000.4
Cash flows from investing activities:
Capital expenditures for property and equipment and computer software	(100.4)	(45.8)
Acquisitions, net of cash acquired	(23.1)	0
Other, net	(6)	(2.3)
Net cash used in investing activities	(129.5)	(48.1)
Cash flows from financing activities:
Repayment of long-term debt	(831.4)	(37.5)
Treasury stock acquired	(420.7)	(837.4)
Commercial paper borrowings (repayments), net	(195)	0
Net proceeds from employee stock plans	82.3	14.5
Other, net	(7.2)	(6.1)
Net intercompany transactions	0	0
Net cash used in financing activities	(1,372)	(866.5)
Effect of foreign currency translation adjustment	(2.1)	0.8
Net increase in cash and cash equivalents	8	86.6
Cash and cash equivalents at beginning of period	2,309.6	3,077.2
Cash and cash equivalents at end of period	2,317.6	3,163.8
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	(15.4)	(28)
Cash flows from investing activities:
Capital expenditures for property and equipment and computer software	0	0
Acquisitions, net of cash acquired	0
Other, net	0	0
Net cash used in investing activities	0	0
Cash flows from financing activities:
Repayment of long-term debt	0	0
Treasury stock acquired	0	0
Commercial paper borrowings (repayments), net	0
Net proceeds from employee stock plans	0	0
Other, net	15.4	28
Net intercompany transactions	0	0
Net cash used in financing activities	15.4	28
Effect of foreign currency translation adjustment	0	0
Net increase in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	0	0
Express Scripts, Inc.
Condensed Financial Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	674.7	725.1
Cash flows from investing activities:
Capital expenditures for property and equipment and computer software	(80.2)	(32.6)
Acquisitions, net of cash acquired	0
Other, net	(3.7)	(4.1)
Net cash used in investing activities	(83.9)	(36.7)
Cash flows from financing activities:
Repayment of long-term debt	0	0
Treasury stock acquired	0	0
Commercial paper borrowings (repayments), net	0
Net proceeds from employee stock plans	0	0
Other, net	(2.8)	0
Net intercompany transactions	(569)	(1,123.5)
Net cash used in financing activities	(571.8)	(1,123.5)
Effect of foreign currency translation adjustment	0	0
Net increase in cash and cash equivalents	19	(435.1)
Cash and cash equivalents at beginning of period	114.5	1,234.2
Cash and cash equivalents at end of period	133.5	799.1
Medco Health Solutions, Inc.
Condensed Financial Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	96	429.2
Cash flows from investing activities:
Capital expenditures for property and equipment and computer software	0	0
Acquisitions, net of cash acquired	0
Other, net	0	0
Net cash used in investing activities	0	0
Cash flows from financing activities:
Repayment of long-term debt	(831.4)	0
Treasury stock acquired	0	0
Commercial paper borrowings (repayments), net	0
Net proceeds from employee stock plans	0	0
Other, net	0	0
Net intercompany transactions	735.4	(433.6)
Net cash used in financing activities	(96)	(433.6)
Effect of foreign currency translation adjustment	0	0
Net increase in cash and cash equivalents	0	(4.4)
Cash and cash equivalents at beginning of period	0	4.4
Cash and cash equivalents at end of period	0	0
Express Scripts Holding Company
Condensed Financial Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	(25.3)	(79.5)
Cash flows from investing activities:
Capital expenditures for property and equipment and computer software	0	0
Acquisitions, net of cash acquired	0
Other, net	0	0
Net cash used in investing activities	0	0
Cash flows from financing activities:
Repayment of long-term debt	0	(37.5)
Treasury stock acquired	(420.7)	(837.4)
Commercial paper borrowings (repayments), net	(195)
Net proceeds from employee stock plans	82.3	14.5
Other, net	(0.1)	0
Net intercompany transactions	653.1	1,767.2
Net cash used in financing activities	119.6	906.8
Effect of foreign currency translation adjustment	0	0
Net increase in cash and cash equivalents	94.3	827.3
Cash and cash equivalents at beginning of period	1,031	583.5
Cash and cash equivalents at end of period	1,125.3	1,410.8
Non-Guarantors
Condensed Financial Statements, Captions [Line Items]
Net cash flows provided by (used in) operating activities	781.6	(46.4)
Cash flows from investing activities:
Capital expenditures for property and equipment and computer software	(20.2)	(13.2)
Acquisitions, net of cash acquired	(23.1)
Other, net	(2.3)	1.8
Net cash used in investing activities	(45.6)	(11.4)
Cash flows from financing activities:
Repayment of long-term debt	0	0
Treasury stock acquired	0	0
Commercial paper borrowings (repayments), net	0
Net proceeds from employee stock plans	0	0
Other, net	(19.7)	(34.1)
Net intercompany transactions	(819.5)	(210.1)
Net cash used in financing activities	(839.2)	(244.2)
Effect of foreign currency translation adjustment	(2.1)	0.8
Net increase in cash and cash equivalents	(105.3)	(301.2)
Cash and cash equivalents at beginning of period	1,164.1	1,255.1
Cash and cash equivalents at end of period	$ 1,058.8	$ 953.9