Merck & Co. (MRK) 10-Q 8 May 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	Apr. 30, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Trading Symbol	'MRK	'
Entity Registrant Name	'Merck & Co. Inc.	'
Entity Central Index Key	'0000310158	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	2,922,376,244

INTERIM_CONSOLIDATED_STATEMENT

INTERIM CONSOLIDATED STATEMENT OF INCOME (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]	'	'
Sales	$10,264	$10,671
Costs, Expenses and Other	'	'
Materials and production	3,903	3,959
Marketing and administrative	2,734	2,987
Research and development	1,574	1,907
Restructuring costs	125	119
Equity income from affiliates	-124	-133
Other (income) expense, net	-39	282
Total Costs, Expenses and Other	8,173	9,121
Income Before Taxes	2,091	1,550
Taxes on Income	360	-66
Net Income	1,731	1,616
Less: Net Income Attributable to Noncontrolling Interests	26	23
Net Income Attributable to Merck & Co., Inc.	$1,705	$1,593
Basic Earnings per Common Share Attributable to Merck & Co., Inc. Common Shareholders, in dollars per share	$0.58	$0.53
Earnings per Common Share Assuming Dilution Attributable to Merck & Co., Inc. Common Shareholders, in dollars per share	$0.57	$0.52
Dividends Declared per Common Share, in dollars per share	$0.44	$0.43

INTERIM_CONSOLIDATED_STATEMENT1

INTERIM CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]	'	'
Net Income Attributable to Merck & Co., Inc.	$1,705	$1,593
Other Comprehensive Income (Loss) Net of Taxes:	'	'
Net unrealized (loss) gain on derivatives, net of reclassifications	-66	236
Net unrealized (loss) gain on investments, net of reclassifications	-2	1
Benefit plan net (loss) gain and prior service (credit) cost, net of amortization	-1	161
Cumulative translation adjustment	87	-345
Other comprehensive income (loss), net of taxes	18	53
Comprehensive Income Attributable to Merck & Co., Inc.	$1,723	$1,646

CONSOLIDATED_BALANCE_SHEET

CONSOLIDATED BALANCE SHEET (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current Assets	'	'
Cash and cash equivalents	$15,828	$15,621
Short-term investments	4,685	1,865
Accounts receivable (net of allowance for doubtful accounts of $171 in 2014 and $146 in 2013) (excludes accounts receivable of $275 in 2014 and 2013 classified in Other assets - see Note 4)	7,188	7,184
Inventories (excludes inventories of $1,493 in 2014 and $1,704 in 2013 classified in Other assets - see Note 5)	6,376	6,226
Deferred income taxes and other current assets	3,939	4,763
Assets held for sale	3,224	26
Total current assets	41,240	35,685
Investments	11,456	9,770
Property, Plant and Equipment, at cost, net of accumulated depreciation of $18,622 in 2014 and $18,121 in 2013	14,296	14,973
Goodwill	12,120	12,301
Other Intangibles, Net	20,517	23,801
Other Assets	8,831	9,115
Total Assets	108,460	105,645
Current Liabilities	'	'
Loans payable and current portion of long-term debt	8,559	4,521
Trade accounts payable	2,434	2,274
Accrued and other current liabilities	8,707	9,501
Income taxes payable	595	251
Dividends payable	1,327	1,321
Liabilities held for sale	848	0
Total current liabilities	22,470	17,868
Long-Term Debt	19,589	20,539
Deferred Income Taxes	5,881	6,776
Other Noncurrent Liabilities	7,956	8,136
Merck & Co., Inc. Stockholders’ Equity	'	'
Common stock, $0.50 par value Authorized - 6,500,000,000 shares Issued - 3,577,103,522 shares in 2014 and 2013	1,788	1,788
Other paid-in capital	40,450	40,508
Retained earnings	39,661	39,257
Accumulated other comprehensive loss	-2,179	-2,197
Stockholders' equity before deduction for treasury stock	79,720	79,356
Less treasury stock, at cost: 647,565,088 shares in 2014 and 649,576,808 shares in 2013	29,745	29,591
Total Merck & Co., Inc. stockholders’ equity	49,975	49,765
Noncontrolling Interests	2,589	2,561
Total equity	52,564	52,326
Liabilities and Equity	$108,460	$105,645

CONSOLIDATED_BALANCE_SHEET_Par

CONSOLIDATED BALANCE SHEET (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Allowance for doubtful accounts	$171	$146
Accounts receivable classified in Other assets	275	275
Inventories classified in Other assets	1,493	1,704
Accumulated depreciation	$18,622	$18,121
Common stock, par value	$0.50	$0.50
Common stock, shares authorized	6,500,000,000	6,500,000,000
Common stock, shares issued	3,577,103,522	3,577,103,522
Treasury stock, shares	647,565,088	649,576,808

INTERIM_CONSOLIDATED_STATEMENT2

INTERIM CONSOLIDATED STATEMENT OF CASH FLOWS (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Cash Flows from Operating Activities	'	'
Net income	$1,731	$1,616
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation and amortization	1,754	1,674
Intangible asset impairment charges	0	30
Equity income from affiliates	-124	-133
Dividends and distributions from equity affiliates	66	5
Deferred income taxes	-304	-71
Share-based compensation	56	67
Other	-115	326
Net changes in assets and liabilities	-703	-1,173
Net Cash Provided by Operating Activities	2,361	2,341
Cash Flows from Investing Activities	'	'
Capital expenditures	-205	-351
Purchases of securities and other investments	-6,825	-4,010
Proceeds from sales of securities and other investments	2,632	3,161
Dispositions of businesses, net of cash divested	533	0
Other	58	47
Net Cash Used in Investing Activities	-3,807	-1,153
Cash Flows from Financing Activities	'	'
Net change in short-term borrowings	3,149	880
Payments on debt	-3	-506
Purchases of treasury stock	-1,167	-580
Dividends paid to stockholders	-1,290	-1,306
Proceeds from exercise of stock options	931	92
Other	0	-1
Net Cash Provided by (Used in) Financing Activities	1,620	-1,421
Effect of Exchange Rate Changes on Cash and Cash Equivalents	33	-194
Net Increase (Decrease) in Cash and Cash Equivalents	207	-427
Cash and Cash Equivalents at Beginning of Year	15,621	13,451
Cash and Cash Equivalents at End of Period	$15,828	$13,024

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited interim consolidated financial statements of Merck & Co., Inc. (“Merck” or the “Company”) have been prepared pursuant to the rules and regulations for reporting on Form 10-Q. Accordingly, certain information and disclosures required by accounting principles generally accepted in the United States for complete consolidated financial statements are not included herein. These interim statements should be read in conjunction with the audited financial statements and notes thereto included in Merck’s Form 10-K filed on February 27, 2014.
	The results of operations of any interim period are not necessarily indicative of the results of operations for the full year. In the Company’s opinion, all adjustments necessary for a fair presentation of these interim statements have been included and are of a normal and recurring nature. Certain reclassifications have been made to prior year amounts to conform to the current presentation.

Restructuring

Restructuring	3 Months Ended
	Mar. 31, 2014
Restructuring and Related Activities [Abstract]	'
Restructuring	'
	Restructuring
	2013 Restructuring Program
	In October 2013, the Company announced a global restructuring program (the “2013 Restructuring Program”) as part of a global initiative to sharpen its commercial and research and development focus. As part of the program, the Company expects to reduce its total workforce by approximately 8,500 positions. These workforce reductions will primarily come from the elimination of positions in sales, administrative and headquarters organizations, as well as research and development. The Company will also reduce its global real estate footprint and continue to improve the efficiency of its manufacturing and supply network. The Company will continue to hire employees in strategic growth areas of the business as necessary.
	The Company recorded total pretax costs of $160 million in the first quarter of 2014 related to this restructuring program. Since inception of the 2013 Restructuring Program through March 31, 2014, Merck has recorded total pretax accumulated costs of approximately $1.4 billion and eliminated approximately 2,760 positions comprised of employee separations, as well as the elimination of contractors and vacant positions. The actions under the 2013 Restructuring Program are expected to be substantially completed by the end of 2015 with the cumulative pretax costs estimated to be approximately $2.5 billion to $3.0 billion. The Company estimates that approximately two-thirds of the cumulative pretax costs will result in cash outlays, primarily related to employee separation expense. Approximately one-third of the cumulative pretax costs are non-cash, relating primarily to the accelerated depreciation of facilities to be closed or divested.
	Merger Restructuring Program
	In 2010, subsequent to the Merck and Schering-Plough Corporation (“Schering-Plough”) merger (the “Merger”), the Company commenced actions under a global restructuring program (the “Merger Restructuring Program”) designed to streamline the cost structure of the combined company. Further actions under this program were initiated in 2011. The actions under this program primarily reflect the elimination of positions in sales, administrative and headquarters organizations, as well as from the sale or closure of certain manufacturing and research and development sites and the consolidation of office facilities.
	On October 1, 2013, the Company sold its active pharmaceutical ingredient (“API”) manufacturing business, including the related manufacturing facility, in the Netherlands to Aspen Holdings (“Aspen”) as part of planned manufacturing facility rationalizations under the Merger Restructuring Program. Also in connection with the sale, Aspen acquired certain branded products from Merck, which transferred to Aspen effective December 31, 2013. Consideration for the transaction included cash of $705 million and notes receivable with a present value of $198 million at the time of disposition. The Company received $172 million of the cash portion of the consideration in the fourth quarter of 2013 and the remaining $533 million was received by the Company in January 2014.
	The Company recorded total pretax costs of $166 million and $153 million in the first quarter of 2014 and 2013, respectively, related to this restructuring program. Since inception of the Merger Restructuring Program through March 31, 2014, Merck has recorded total pretax accumulated costs of approximately $7.3 billion and eliminated approximately 27,240 positions comprised of employee separations, as well as the elimination of contractors and vacant positions. Approximately 5,600 position eliminations remain pending under this program as of March 31, 2014, which include the remaining actions under the 2008 Restructuring Program that are being reported as part of the Merger Restructuring Program as discussed below. The non-manufacturing related restructuring actions under the Merger Restructuring Program were substantially completed by the end of 2013. The remaining actions under this program relate to ongoing manufacturing facility rationalizations, which are expected to be substantially completed by 2016. The Company expects the estimated total cumulative pretax costs for this program to be approximately $7.4 billion to $7.7 billion. The Company estimates that approximately two-thirds of the cumulative pretax costs relate to cash outlays, primarily related to employee separation expense. Approximately one-third of the cumulative pretax costs are non-cash, relating primarily to the accelerated depreciation of facilities to be closed or divested.
	2008 Restructuring Program
	In 2008, Merck announced a global restructuring program (the “2008 Restructuring Program”) to reduce its cost structure, increase efficiency, and enhance competitiveness. Pretax costs of $41 million were recorded in the first quarter of 2013 related to the 2008 Restructuring Program. Any remaining activities under the 2008 Restructuring Program are being accounted for as part of the Merger Restructuring Program effective July 1, 2013.
	For segment reporting, restructuring charges are unallocated expenses.
	The following tables summarize the charges related to restructuring program activities by type of cost:
		Three Months Ended March 31, 2014
	($ in millions)	Separation			Accelerated			Other			Total
		Costs			Depreciation
	2013 Restructuring Program
	Materials and production	$	—		$	81		$	6		$	87
	Marketing and administrative	—			19			—			19
	Research and development	—			41			7			48
	Restructuring costs	25			—			(19		)	6
		25			141			(6		)	160
	Merger Restructuring Program
	Materials and production	—			68			(36		)	32
	Marketing and administrative	—			12			—			12
	Research and development	—			2			1			3
	Restructuring costs	29			—			90			119
		29			82			55			166
		$	54		$	223		$	49		$	326
		Three Months Ended March 31, 2013
	($ in millions)	Separation			Accelerated			Other			Total
		Costs			Depreciation
	Merger Restructuring Program
	Materials and production	$	—		$	31		$	9		$	40
	Marketing and administrative	—			15			—			15
	Research and development	—			15			—			15
	Restructuring costs	65			—			18			83
		65			61			27			153
	2008 Restructuring Program
	Materials and production	—			—			3			3
	Marketing and administrative	—			2			—			2
	Restructuring costs	32			—			4			36
		32			2			7			41
		$	97		$	63		$	34		$	194
	Separation costs are associated with actual headcount reductions, as well as those headcount reductions which were probable and could be reasonably estimated. In the first quarter of 2014, approximately 1,220 positions were eliminated under the 2013 Restructuring Program. In the first quarter of 2014 and 2013, approximately 360 positions and 740 positions, respectively, were eliminated under the Merger Restructuring Program. In addition, approximately 50 positions were eliminated in the first quarter of 2013 under the 2008 Restructuring Program. These position eliminations were comprised of actual headcount reductions and the elimination of contractors and vacant positions.
	Accelerated depreciation costs primarily relate to manufacturing, research and administrative facilities and equipment to be sold or closed as part of the programs. Accelerated depreciation costs represent the difference between the depreciation expense to be recognized over the revised useful life of the site, based upon the anticipated date the site will be closed or divested, and depreciation expense as determined utilizing the useful life prior to the restructuring actions. All of the sites have and will continue to operate up through the respective closure dates and, since future undiscounted cash flows were sufficient to recover the respective book values, Merck was required to accelerate depreciation of the site assets rather than record an impairment charge. Anticipated site closure dates, particularly related to manufacturing locations, have been and may continue to be adjusted to reflect changes resulting from regulatory or other factors.
	Other activity in 2014 and 2013 includes pretax gains and losses resulting from sales of facilities and related assets, as well as asset abandonment, shut-down and other related costs. Additionally, other activity includes certain employee-related costs associated with pension and other postretirement benefit plans (see Note 11) and share-based compensation.
	Adjustments to previously recorded amounts were not material in any period.
	The following table summarizes the charges and spending relating to restructuring activities by program for the three months ended March 31, 2014:
	($ in millions)	Separation			Accelerated			Other			Total
		Costs			Depreciation
	2013 Restructuring Program
	Restructuring reserves January 1, 2014	$	745		$	—		$	23		$	768
	Expense	25			141			(6		)	160
	(Payments) receipts, net	(235		)	—			(19		)	(254		)
	Non-cash activity	—			(141		)	19			(122		)
	Restructuring reserves March 31, 2014 (1)	$	535		$	—		$	17		$	552
	Merger Restructuring Program
	Restructuring reserves January 1, 2014	$	725		$	—		$	12		$	737
	Expense	29			82			55			166
	(Payments) receipts, net	(77		)	—			(35		)	(112		)
	Non-cash activity	—			(82		)	(21		)	(103		)
	Restructuring reserves March 31, 2014 (1)	$	677		$	—		$	11		$	688
	(1)	The cash outlays associated with the 2013 Restructuring Program are expected to be substantially completed by the end of 2015. The cash outlays associated with the Merger Restructuring Program were substantially completed by the end of 2013 with the exception of certain actions, principally manufacturing-related, which are expected to be substantially completed by 2016.

Acquisitions_Divestitures_Rese

Acquisitions, Divestitures, Research Collaborations and License Agreements	3 Months Ended
	Mar. 31, 2014
Business Combinations [Abstract]	'
Acquisitions, Divestitures, Research Collaborations and License Agreements	'
	Acquisitions, Divestitures, Research Collaborations and License Agreements
	The Company continues its strategy of establishing external alliances to complement its substantial internal research capabilities, including research collaborations, licensing preclinical and clinical compounds to drive both near- and long-term growth. The Company supplements its internal research with a licensing and external alliance strategy focused on the entire spectrum of collaborations from early research to late-stage compounds, as well as access to new technologies. These arrangements often include upfront payments, as well as expense reimbursements or payments to the third party, and milestone, royalty or profit share payments, contingent upon the occurrence of certain future events linked to the success of the asset in development. The Company also reviews its pipeline to examine candidates which may provide more value through out-licensing and as part of its portfolio assessment process may also divest certain products.
	In January 2014, Merck sold the U.S. marketing rights to Saphris (asenapine), an antipsychotic indicated for the treatment of schizophrenia and bipolar I disorder in adults to Forest Laboratories, Inc. (“Forest”). Under the terms of the agreement, Forest made upfront payments of $232 million, which were recorded in Sales in the first quarter of 2014, and will make additional payments to Merck based on defined sales milestones. In addition, as part of this transaction, Merck has agreed to supply product to Forest until patent expiry.
	In March 2014, Merck divested its Sirna Therapeutics, Inc. (“Sirna”) subsidiary to Alnylam Pharmaceuticals, Inc. (“Alnylam”) for consideration of $25 million and 2,520,044 shares of Alnylam common stock. Under the terms of the agreement, Merck received 85% of the Alnylam shares in the first quarter of 2014 (valued at $172 million at the time of closing) and the remaining 15% of the shares will be received by Merck later in 2014. Merck recorded a gain of $182 million included in Other (income) expense, net in the first quarter of 2014 related to this transaction. Upon receipt of the remaining shares of Alnylam, the Company will recognize an additional gain based on the market value of the Alnylam shares when received. Merck is eligible to receive future payments associated with the achievement of certain regulatory and commercial milestones, as well as royalties on future sales. The excess of Merck’s tax basis in its investment in Sirna over the value received resulted in an approximate $300 million tax benefit recorded in the first quarter of 2014.
	In April 2013, Merck and Pfizer Inc. (“Pfizer”) announced that they had entered into a worldwide (except Japan) collaboration agreement for the development and commercialization of Pfizer’s ertugliflozin, an investigational oral sodium glucose cotransporter (“SGLT2”) inhibitor being evaluated for the treatment of type 2 diabetes. The Company has initiated Phase 3 clinical trials for ertugliflozin with Pfizer. Under the terms of the agreement, Merck and Pfizer will collaborate on the clinical development and commercialization of ertugliflozin and ertugliflozin-containing fixed-dose combinations with metformin and with Januvia (sitagliptin) tablets. Merck will continue to retain the rights to its existing portfolio of sitagliptin-containing products. Through the first quarter of 2013, Merck recorded research and development expenses of $60 million for upfront and milestone payments made to Pfizer. Pfizer will be eligible for additional payments associated with the achievement of pre-specified future clinical, regulatory and commercial milestones. The companies will share potential revenues and certain costs 60% to Merck and 40% to Pfizer. Each party will have certain manufacturing and supply obligations. The Company and Pfizer each have the right to terminate the agreement due to a material, uncured breach by, or insolvency of, the other party, or in the event of a safety issue. Pfizer has the right to terminate the agreement upon 12 months notice at any time following the first anniversary of the first commercial sale of a collaboration product, but must assign all rights to ertugliflozin to Merck. Upon termination of the agreement, depending upon the circumstances, the parties have varying rights and obligations with respect to the continued development and commercialization of ertugliflozin and certain payment obligations.
	In February 2013, Merck and Supera Farma Laboratorios S.A. (“Supera”), a Brazilian pharmaceutical company co-owned by Cristália and Eurofarma, established the previously announced joint venture that markets, distributes and sells a portfolio of pharmaceutical and branded generic products from Merck, Cristália and Eurofarma in Brazil. Merck owns 51% of the joint venture, and Cristália and Eurofarma collectively own 49%. The transaction was accounted for as an acquisition of a business; accordingly, the assets acquired and liabilities assumed were recorded at their respective fair values. This resulted in Merck recognizing intangible assets for currently marketed products of $89 million, in-process research and development (“IPR&D”) of $100 million, goodwill of $103 million, and deferred tax liabilities of $64 million. The Company also recorded increases to Noncontrolling interests and Other paid-in capital in the amounts of $112 million and $116 million, respectively. This transaction closed on February 1, 2013, and accordingly, the results of operations of the acquired business have been included in the Company’s results of operations beginning after that date. During the fourth quarter of 2013, as a result of changes in cash flow assumptions for certain compounds, the Company recorded $15 million of impairment charges related to the IPR&D recorded in the Supera transaction.
	Merck Consumer Care
	In May 2014, the Company announced that it had entered into a definitive agreement to sell its Merck Consumer Care (“MCC”) business to Bayer AG (“Bayer”) for $14.2 billion. Under the terms of the agreement, Bayer will acquire Merck’s existing over-the-counter (“OTC”) business, including the global trademark and prescription rights for Claritin and Afrin.
	The Company also announced a worldwide clinical development collaboration with Bayer to market and develop its portfolio of soluble guanylate cyclase (“sGC”) modulators. This includes Bayer’s Adempas (riociguat), the first member of this novel class of compounds. Adempas is approved to treat pulmonary arterial hypertension (“PAH”) and is the first and only drug treatment approved for patients with chronic thromboembolic pulmonary hypertension (“CTEPH”). Adempas is currently marketed in the United States and Europe for both PAH and CTEPH and in Japan for CTEPH. The two companies will equally share costs and profits from the collaboration and implement a joint development and commercialization strategy. The collaboration also includes clinical development of Bayer’s vericiguat, which is currently in Phase 2 trials for worsening heart failure, as well as opt-in rights for other early-stage sGC compounds in development at Bayer. Merck will in turn make available its early-stage sGC compounds under similar terms.
	In return for these broad collaboration rights, Merck will make an upfront payment to Bayer of $1 billion with the potential for additional milestone payments upon the achievement of agreed-upon sales goals. For Adempas, Bayer will continue to lead commercialization in the Americas, while Merck will lead commercialization in the rest of the world. For vericiguat and other potential opt-in products, Bayer will lead in the rest of world and Merck will lead in the Americas. For all products and candidates included in the agreement, both companies will share in development costs and profits on sales and will have the right to co-promote in territories where they are not the lead.
	The Company expects after-tax proceeds from the sale of MCC to be between $8 billion and $9 billion. Merck expects to close the sale of MCC in second half of 2014, subject to customary closing conditions, including regulatory approvals.
	At March 31, 2014, the Company determined it was appropriate to reflect the assets and liabilities of Merck Consumer Care as held for sale in the Consolidated Balance Sheet. Information with respect to Consumer Care assets and liabilities held for sale is as follows:
	($ millions)	31-Mar-14
	Assets
	Accounts receivable, net	$	207
	Inventories	316
	Deferred income taxes and other current assets	48
	Property, plant and equipment, net	221
	Goodwill	137
	Other intangibles, net	2,194
	Other assets	66
		$	3,189
	Liabilities
	Trade accounts payable	$	101
	Accrued and other current liabilities	193
	Deferred income taxes	543
	Other noncurrent liabilities	11
		$	848
	Remicade/Simponi
	In 1998, a subsidiary of Schering-Plough entered into a licensing agreement with Centocor Ortho Biotech Inc. (“Centocor”), a Johnson & Johnson (“J&J”) company, to market Remicade, which is prescribed for the treatment of inflammatory diseases. In 2005, Schering-Plough’s subsidiary exercised an option under its contract with Centocor for license rights to develop and commercialize Simponi, a fully human monoclonal antibody. The Company has exclusive marketing rights to both products throughout Europe, Russia and Turkey. In December 2007, Schering-Plough and Centocor revised their distribution agreement regarding the development, commercialization and distribution of both Remicade and Simponi, extending the Company’s rights to exclusively market Remicade to match the duration of the Company’s exclusive marketing rights for Simponi. In addition, Schering-Plough and Centocor agreed to share certain development costs relating to Simponi’s auto-injector delivery system. On October 6, 2009, the European Commission approved Simponi as a treatment for rheumatoid arthritis and other immune system disorders in two presentations – a novel auto-injector and a prefilled syringe. As a result, the Company’s marketing rights for both products extend for 15 years from the first commercial sale of Simponi in the European Union (the “EU”) following the receipt of pricing and reimbursement approval within the EU. All profits derived from Merck’s exclusive distribution of the two products in these countries are equally divided between Merck and J&J.

Financial_Instruments

Financial Instruments	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Financial Instruments	'
	Financial Instruments
	Derivative Instruments and Hedging Activities
	The Company manages the impact of foreign exchange rate movements and interest rate movements on its earnings, cash flows and fair values of assets and liabilities through operational means and through the use of various financial instruments, including derivative instruments.
	A significant portion of the Company’s revenues and earnings in foreign affiliates is exposed to changes in foreign exchange rates. The objectives and accounting related to the Company’s foreign currency risk management program, as well as its interest rate risk management activities are discussed below.
	Foreign Currency Risk Management
	The Company has established revenue hedging, balance sheet risk management and net investment hedging programs to protect against volatility of future foreign currency cash flows and changes in fair value caused by volatility in foreign exchange rates.
	The objective of the revenue hedging program is to reduce the potential for longer-term unfavorable changes in foreign exchange rates to decrease the U.S. dollar value of future cash flows derived from foreign currency denominated sales, primarily the euro and Japanese yen. To achieve this objective, the Company will hedge a portion of its forecasted foreign currency denominated third-party and intercompany distributor entity sales that are expected to occur over its planning cycle, typically no more than three years into the future. The Company will layer in hedges over time, increasing the portion of third-party and intercompany distributor entity sales hedged as it gets closer to the expected date of the forecasted foreign currency denominated sales. The portion of sales hedged is based on assessments of cost-benefit profiles that consider natural offsetting exposures, revenue and exchange rate volatilities and correlations, and the cost of hedging instruments. The hedged anticipated sales are a specified component of a portfolio of similarly denominated foreign currency-based sales transactions, each of which responds to the hedged currency risk in the same manner. The Company manages its anticipated transaction exposure principally with purchased local currency put options, which provide the Company with a right, but not an obligation, to sell foreign currencies in the future at a predetermined price. If the U.S. dollar strengthens relative to the currency of the hedged anticipated sales, total changes in the options’ cash flows offset the decline in the expected future U.S. dollar equivalent cash flows of the hedged foreign currency sales. Conversely, if the U.S. dollar weakens, the options’ value reduces to zero, but the Company benefits from the increase in the U.S. dollar equivalent value of the anticipated foreign currency cash flows.
	In connection with the Company’s revenue hedging program, a purchased collar option strategy may be utilized. With a purchased collar option strategy, the Company writes a local currency call option and purchases a local currency put option. As compared to a purchased put option strategy alone, a purchased collar strategy reduces the upfront costs associated with purchasing puts through the collection of premium by writing call options. If the U.S. dollar weakens relative to the currency of the hedged anticipated sales, the purchased put option value of the collar strategy reduces to zero and the Company benefits from the increase in the U.S. dollar equivalent value of its anticipated foreign currency cash flows, however this benefit would be capped at the strike level of the written call. If the U.S. dollar strengthens relative to the currency of the hedged anticipated sales, the written call option value of the collar strategy reduces to zero and the changes in the purchased put cash flows of the collar strategy would offset the decline in the expected future U.S. dollar equivalent cash flows of the hedged foreign currency sales.
	The Company may also utilize forward contracts in its revenue hedging program. If the U.S. dollar strengthens relative to the currency of the hedged anticipated sales, the increase in the fair value of the forward contracts offsets the decrease in the expected future U.S. dollar cash flows of the hedged foreign currency sales. Conversely, if the U.S. dollar weakens, the decrease in the fair value of the forward contracts offsets the increase in the value of the anticipated foreign currency cash flows.
	The fair values of these derivative contracts are recorded as either assets (gain positions) or liabilities (loss positions) in the Consolidated Balance Sheet. Changes in the fair value of derivative contracts are recorded each period in either current earnings or Other comprehensive income (“OCI”), depending on whether the derivative is designated as part of a hedge transaction and, if so, the type of hedge transaction. For derivatives that are designated as cash flow hedges, the effective portion of the unrealized gains or losses on these contracts is recorded in Accumulated other comprehensive income (“AOCI”) and reclassified into Sales when the hedged anticipated revenue is recognized. The hedge relationship is highly effective and hedge ineffectiveness has been de minimis. For those derivatives which are not designated as cash flow hedges, but serve as economic hedges of forecasted sales, unrealized gains or losses are recorded in Sales each period. The cash flows from both designated and non-designated contracts are reported as operating activities in the Consolidated Statement of Cash Flows. The Company does not enter into derivatives for trading or speculative purposes.
	The primary objective of the balance sheet risk management program is to mitigate the exposure of foreign currency denominated net monetary assets of foreign subsidiaries where the U.S. dollar is the functional currency from the effects of volatility in foreign exchange. In these instances, Merck principally utilizes forward exchange contracts, which enable the Company to buy and sell foreign currencies in the future at fixed exchange rates and economically offset the consequences of changes in foreign exchange from the monetary assets. Merck routinely enters into contracts to offset the effects of exchange on exposures denominated in developed country currencies, primarily the euro and Japanese yen. For exposures in developing country currencies, the Company will enter into forward contracts to partially offset the effects of exchange on exposures when it is deemed economical to do so based on a cost-benefit analysis that considers the magnitude of the exposure, the volatility of the exchange rate and the cost of the hedging instrument. The Company will also minimize the effect of exchange on monetary assets and liabilities by managing operating activities and net asset positions at the local level. The cash flows from these contracts are reported as operating activities in the Consolidated Statements of Cash Flows.
	Monetary assets and liabilities denominated in a currency other than the functional currency of a given subsidiary are remeasured at spot rates in effect on the balance sheet date with the effects of changes in spot rates reported in Other (income) expense, net. The forward contracts are not designated as hedges and are marked to market through Other (income) expense, net. Accordingly, fair value changes in the forward contracts help mitigate the changes in the value of the remeasured assets and liabilities attributable to changes in foreign currency exchange rates, except to the extent of the spot-forward differences. These differences are not significant due to the short-term nature of the contracts, which typically have average maturities at inception of less than one year.
	The Company also uses forward exchange contracts to hedge its net investment in foreign operations against movements in exchange rates. The forward contracts are designated as hedges of the net investment in a foreign operation. The Company hedges a portion of the net investment in certain of its foreign operations and measures ineffectiveness based upon changes in spot foreign exchange rates. The effective portion of the unrealized gains or losses on these contracts is recorded in foreign currency translation adjustment within OCI, and remains in AOCI until either the sale or complete or substantially complete liquidation of the subsidiary. The cash flows from these contracts are reported as investing activities in the Consolidated Statement of Cash Flows.
	Foreign exchange risk is also managed through the use of foreign currency debt. The Company’s senior unsecured euro-denominated notes have been designated as, and are effective as, economic hedges of the net investment in a foreign operation. Accordingly, foreign currency transaction gains or losses due to spot rate fluctuations on the euro-denominated debt instruments are included in foreign currency translation adjustment within OCI. Included in the cumulative translation adjustment are pretax gains of $12 million and $78 million for the first three months of 2014 and 2013, respectively, from the euro-denominated notes.
	Interest Rate Risk Management
	The Company may use interest rate swap contracts on certain investing and borrowing transactions to manage its net exposure to interest rate changes and to reduce its overall cost of borrowing. The Company does not use leveraged swaps and, in general, does not leverage any of its investment activities that would put principal capital at risk.
	At March 31, 2014, the Company was party to a total of 15 pay-floating, receive-fixed interest rate swap contracts designated as fair value hedges of fixed-rate notes in which the notional amounts match the amount of the hedged fixed-rate notes. There are four swaps maturing in 2016 with notional amounts of $250 million each that effectively convert the Company’s 0.70% fixed-rate notes due in 2016 to floating-rate instruments; four swaps maturing in 2018 with notional amounts of $250 million each that effectively convert the Company’s 1.30% fixed-rate notes due in 2018 to floating-rate instruments; four swaps maturing in 2017, one with a notional amount of $200 million, two with notional amounts of $250 million each, and one with a notional amount of $300 million, that effectively convert the Company’s 6.00% fixed-rate notes due in 2017 to floating-rate instruments; and three swaps maturing in 2019, two with notional amounts of $200 million each, and one with a notional amount of $150 million, that effectively convert a portion of the Company’s 5.00% notes due in 2019 to floating rate instruments. The interest rate swap contracts are designated hedges of the fair value changes in the notes attributable to changes in the benchmark London Interbank Offered Rate (“LIBOR”) swap rate. The fair value changes in the notes attributable to changes in the LIBOR are recorded in interest expense and offset by the fair value changes in the swap contracts. The cash flows from these contracts are reported as operating activities in the Consolidated Statement of Cash Flows.
	Presented in the table below is the fair value of derivatives on a gross basis segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments:
			31-Mar-14									31-Dec-13
			Fair Value of Derivative						U.S. Dollar			Fair Value of Derivative						U.S. Dollar
	($ in millions)	Balance Sheet Caption	Asset			Liability			Notional			Asset			Liability			Notional
	Derivatives Designated as Hedging Instruments
	Interest rate swap contracts (non-current)	Other assets	$	14		$	—		$	1,550		$	13		$	—		$	1,550
	Interest rate swap contracts (non-current)	Other noncurrent liabilities	—			22			2,000			—			25			2,000
	Foreign exchange contracts (current)	Deferred income taxes and other current assets	402			—			5,541			493			—			4,427
	Foreign exchange contracts (non-current)	Other assets	387			—			6,158			515			—			6,676
	Foreign exchange contracts (current)	Accrued and other current liabilities	—			10			1,245			—			19			1,659
	Foreign exchange contracts (non-current)	Other noncurrent liabilities	—			3			475			—			—			—
			$	803		$	35		$	16,969		$	1,021		$	44		$	16,312
	Derivatives Not Designated as Hedging Instruments
	Foreign exchange contracts (current)	Deferred income taxes and other current assets	$	74		$	—		$	7,161		$	69		$	—		$	5,705
	Foreign exchange contracts (current)	Accrued and other current liabilities	—			71			6,441			—			140			7,892
			$	74		$	71		$	13,602		$	69		$	140		$	13,597
			$	877		$	106		$	30,571		$	1,090		$	184		$	29,909
	As noted above, the Company records its derivatives on a gross basis in the Consolidated Balance Sheet. The Company has master netting agreements with several of its financial institution counterparties (see Concentrations of Credit Risk below). The following table provides information on the Company’s derivative positions subject to these master netting arrangements as if they were presented on a net basis, allowing for the right of offset by counterparty and cash collateral exchanged per the master agreements and related credit support annexes:
		31-Mar-14						31-Dec-13
	($ in millions)	Asset			Liability			Asset			Liability
	Gross amounts recognized in the consolidated balance sheet	$	877		$	106		$	1,090		$	184
	Gross amount subject to offset in master netting arrangements	(102		)	(102		)	(147		)	(147		)
	not offset in the consolidated balance sheet
	Cash collateral (received) posted	(478		)	—			(652		)	—
	Net amounts	$	297		$	4		$	291		$	37
	The table below provides information on the location and pretax gain or loss amounts for derivatives that are: (i) designated in a fair value hedging relationship, (ii) designated in a foreign currency cash flow hedging relationship, (iii) designated in a foreign currency net investment hedging relationship and (iv) not designated in a hedging relationship:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Derivatives designated in a fair value hedging relationship
	Interest rate swap contracts
	Amount of gain recognized in Other (income) expense, net on derivatives	$	(4	)	$	—
	Amount of loss recognized in Other (income) expense, net on hedged item	4			—
	Derivatives designated in foreign currency cash flow hedging relationships
	Foreign exchange contracts
	Amount of loss reclassified from AOCI to Sales	2			32
	Amount of loss (gain) recognized in OCI on derivatives	102			(349		)
	Derivatives designated in foreign currency net investment hedging relationships
	Foreign exchange contracts
	Amount of gain recognized in Other (income) expense, net on derivatives (1)	(2		)	(2		)
	Amount of loss (gain) recognized in OCI on derivatives	42			(180		)
	Derivatives not designated in a hedging relationship
	Foreign exchange contracts
	Amount of (gain) loss recognized in Other (income) expense, net on derivatives (2)	(82		)	24
	Amount of gain recognized in Sales	(1		)	(10		)
	(1) There was no ineffectiveness on the hedge. Represents the amount excluded from hedge effectiveness testing.
(2) These derivative contracts mitigate changes in the value of remeasured foreign currency denominated monetary assets and liabilities attributable to changes in foreign currency exchange rates.
At March 31, 2014, the Company estimates $62 million of pretax net unrealized gains on derivatives maturing within the next 12 months that hedge foreign currency denominated sales over that same period will be reclassified from AOCI to Sales. The amount ultimately reclassified to Sales may differ as foreign exchange rates change. Realized gains and losses are ultimately determined by actual exchange rates at maturity.
Investments in Debt and Equity Securities
Information on available-for-sale investments is as follows:
	31-Mar-14												31-Dec-13
	Fair			Amortized			Gross Unrealized						Fair			Amortized			Gross Unrealized
($ in millions)	Value			Cost			Gains			Losses			Value			Cost			Gains		Losses
Corporate notes and bonds	$	7,883		$	7,854		$	38		$	(9	)	$	7,054		$	7,037		$	32	$	(15	)
Commercial paper	3,622			3,622			—			—			1,206			1,206			—		—
U.S. government and agency securities	1,882			1,885			1			(4		)	1,236			1,239			1		(4		)
Asset-backed securities	1,230			1,232			2			(4		)	1,300			1,303			1		(4		)
Foreign government bonds	641			641			1			(1		)	125			126			—		(1		)
Mortgage-backed securities	497			499			2			(4		)	476			479			2		(5		)
Equity securities	637			587			78			(28		)	471			397			74		—
	$	16,392		$	16,320		$	122		$	(50	)	$	11,868		$	11,787		$	110	$	(29	)
Available-for-sale debt securities included in Short-term investments totaled $4.7 billion at March 31, 2014. Of the remaining debt securities, $10.3 billion mature within five years. At March 31, 2014 and December 31, 2013, there were no debt securities pledged as collateral.
Fair Value Measurements
Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company uses a fair value hierarchy which maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value. There are three levels of inputs used to measure fair value with Level 1 having the highest priority and Level 3 having the lowest:
Level 1 - Quoted prices (unadjusted) in active markets for identical assets or liabilities.
Level 2 - Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
Level 3 - Unobservable inputs that are supported by little or no market activity. Level 3 assets are those whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques with significant unobservable inputs, as well as instruments for which the determination of fair value requires significant judgment or estimation.
If the inputs used to measure the financial assets and liabilities fall within more than one level described above, the categorization is based on the lowest level input that is significant to the fair value measurement of the instrument.
Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis
Financial assets and liabilities measured at fair value on a recurring basis are summarized below:
	Fair Value Measurements Using												Fair Value Measurements Using
	Quoted Prices			Significant			Significant			Total			Quoted Prices			Significant			Significant		Total
	In Active			Other			Unobservable						In Active			Other			Unobservable
	Markets for			Observable			Inputs						Markets for			Observable			Inputs
	Identical Assets			Inputs			(Level 3)						Identical Assets			Inputs			(Level 3)
	(Level 1)			(Level 2)									(Level 1)			(Level 2)
($ in millions)	31-Mar-14												31-Dec-13
Assets
Investments
Corporate notes and bonds	$	—		$	7,883		$	—		$	7,883		$	—		$	7,054		$	—	$	7,054
Commercial paper	—			3,622			—			3,622			—			1,206			—		1,206
U.S. government and agency securities	—			1,882			—			1,882			—			1,236			—		1,236
Asset-backed securities (1)	—			1,230			—			1,230			—			1,300			—		1,300
Foreign government bonds	—			641			—			641			—			125			—		125
Mortgage-backed securities (1)	—			497			—			497			—			476			—		476
Equity securities	386			—			—			386			238			—			—		238
	386			15,755			—			16,141			238			11,397			—		11,635
Other assets
Securities held for employee compensation	195			56			—			251			186			47			—		233
Derivative assets (2)
Purchased currency options	—			734			—			734			—			868			—		868
Forward exchange contracts	—			129			—			129			—			209			—		209
Interest rate swaps	—			14			—			14			—			13			—		13
	—			877			—			877			—			1,090			—		1,090
Total assets	$	581		$	16,688		$	—		$	17,269		$	424		$	12,534		$	—	$	12,958
Liabilities
Derivative liabilities (2)
Forward exchange contracts	$	—		$	58		$	—		$	58		$	—		$	134		$	—	$	134
Written currency options	—			26			—			26			—			25			—		25
Interest rate swaps	—			22			—			22			—			25			—		25
Total liabilities	$	—		$	106		$	—		$	106		$	—		$	184		$	—	$	184
(1)	Primarily all of the asset-backed securities are highly-rated (Standard & Poor’s rating of AAA and Moody’s Investors Service rating of Aaa), secured primarily by credit card, auto loan, and home equity receivables, with weighted-average lives of primarily 5 years or less. Mortgage-backed securities represent AAA-rated securities issued or unconditionally guaranteed as to payment of principal and interest by U.S. government agencies.
(2)	The fair value determination of derivatives includes the impact of the credit risk of counterparties to the derivatives and the Company’s own credit risk, the effects of which were not significant.
There were no transfers between Level 1 and Level 2 during the first three months of 2014. As of March 31, 2014, Cash and cash equivalents of $15.8 billion included $14.7 billion of cash equivalents (considered Level 2 in the fair value hierarchy). The Company has liabilities related to contingent consideration (considered Level 3 in the fair value hierarchy) associated with business combinations, the fair values of which were $71 million and $69 million at March 31, 2014 and December 31, 2013, respectively.
Other Fair Value Measurements
Some of the Company’s financial instruments, such as cash and cash equivalents, receivables and payables, are reflected in the balance sheet at carrying value, which approximates fair value due to their short-term nature.
The estimated fair value of loans payable and long-term debt (including current portion) at March 31, 2014, was $28.9 billion compared with a carrying value of $28.1 billion and at December 31, 2013, was $25.5 billion compared with a carrying value of $25.1 billion. Fair value was estimated using recent observable market prices and would be considered Level 2 in the fair value hierarchy.
Concentrations of Credit Risk
On an ongoing basis, the Company monitors concentrations of credit risk associated with corporate and government issuers of securities and financial institutions with which it conducts business. Credit exposure limits are established to limit a concentration with any single issuer or institution. Cash and investments are placed in instruments that meet high credit quality standards as specified in the Company’s investment policy guidelines.
The majority of the Company’s accounts receivable arise from product sales in the United States and Europe and are primarily due from drug wholesalers and retailers, hospitals, government agencies, managed health care providers and pharmacy benefit managers. The Company monitors the financial performance and creditworthiness of its customers so that it can properly assess and respond to changes in their credit profile. The Company also continues to monitor economic conditions, including the volatility associated with international sovereign economies, and associated impacts on the financial markets and its business, taking into consideration global economic conditions and the ongoing sovereign debt issues in certain European countries. The Company continues to monitor the credit and economic conditions within Greece, Italy, Spain and Portugal, among other members of the EU. These economic conditions, as well as inherent variability of timing of cash receipts, have resulted in, and may continue to result in, an increase in the average length of time that it takes to collect accounts receivable outstanding. As such, time value of money discounts have been recorded for those customers for which collection of accounts receivable is expected to be in excess of one year. At March 31, 2014 and December 31, 2013, Other assets included $275 million of accounts receivable not expected to be collected within one year. The Company does not expect to have write-offs or adjustments to accounts receivable which would have a material adverse effect on its financial position, liquidity or results of operations.
At March 31, 2014, the Company’s accounts receivable in Greece, Italy, Spain and Portugal totaled approximately $940 million. Of this amount, hospital and public sector receivables were approximately $610 million in the aggregate, of which approximately 11%, 45%, 33% and 11% related to Greece, Italy, Spain and Portugal, respectively. At March 31, 2014, the Company’s total net accounts receivable outstanding for more than one year were approximately $180 million, of which approximately 50% related to accounts receivable in Greece, Italy, Spain and Portugal, mostly comprised of hospital and public sector receivables.
Additionally, the Company continues to expand in the emerging markets. Payment terms in these markets tend to be longer, resulting in an increase in accounts receivable balances in certain of these markets.
Derivative financial instruments are executed under International Swaps and Derivatives Association master agreements. The master agreements with several of the Company’s financial institution counterparties also include credit support annexes. These annexes contain provisions that require collateral to be exchanged depending on the value of the derivative assets and liabilities, the Company’s credit rating, and the credit rating of the counterparty. As of March 31, 2014 and December 31, 2013, the Company had received cash collateral of $478 million and $652 million, respectively, from various counterparties and the obligation to return such collateral is recorded in Accrued and other current liabilities. The Company had not advanced any cash collateral to counterparties as of March 31, 2014 or December 31, 2013.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2014
Inventory Disclosure [Abstract]	'
Inventories	'
	Inventories
	Inventories consisted of:
	($ in millions)	31-Mar-14		31-Dec-13
	Finished goods	$	1,642	$	1,738
	Raw materials and work in process	5,889		5,894
	Supplies	222		225
	Total (approximates current cost)	7,753		7,857
	Increase to LIFO costs	116		73
		$	7,869	$	7,930
	Recognized as:
	Inventories	$	6,376	$	6,226
	Other assets	1,493		1,704
	Amounts recognized as Other assets are comprised almost entirely of raw materials and work in process inventories. At March 31, 2014 and December 31, 2013, these amounts included $1.3 billion and $1.5 billion, respectively, of inventories not expected to be sold within one year. In addition, these amounts included $208 million and $177 million at March 31, 2014 and December 31, 2013, respectively, of inventories produced in preparation for product launches.

Other_Intangibles

Other Intangibles	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Other Intangibles	'
	Other Intangibles
	In connection with mergers and acquisitions, the Company measures the fair value of marketed products and research and development pipeline programs and capitalizes these amounts. During the first quarter of 2013, the Company recorded $30 million of IPR&D impairment charges within Research and development expenses primarily for pipeline programs that had previously been deprioritized and were subsequently deemed to have no alternative use in the period. The Company may recognize additional non-cash impairment charges in the future related to other pipeline programs or marketed products and such charges could be material.

Joint_Ventures_and_Other_Equit

Joint Ventures and Other Equity Method Affiliates	3 Months Ended
	Mar. 31, 2014
Equity Method Investments and Joint Ventures [Abstract]	'
Joint Ventures and Other Equity Method Affiliates	'
	Joint Ventures and Other Equity Method Affiliates
	Equity income from affiliates reflects the performance of the Company’s joint ventures and other equity method affiliates and was comprised of the following:
		Three Months Ended
		March 31,
	($ in millions)	2014		2013
	AstraZeneca LP	$	98	$	125
	Other (1)	26		8
		$	124	$	133
	(1)	Includes results from Sanofi Pasteur MSD.
	AstraZeneca LP
	In 1998, Merck and Astra completed the restructuring of the ownership and operations of their existing joint venture whereby Merck acquired Astra’s interest in KBI Inc. (“KBI”) and contributed KBI’s operating assets to a new U.S. limited partnership, Astra Pharmaceuticals L.P. (the “Partnership”), in exchange for a 1% limited partner interest. Astra contributed the net assets of its wholly owned subsidiary, Astra USA, Inc., to the Partnership in exchange for a 99% general partner interest. The Partnership, renamed AstraZeneca LP (“AZLP”) upon Astra’s 1999 merger with Zeneca Group Plc, became the exclusive distributor of the products for which KBI retained rights.
	In April 2014, AstraZeneca notified the Company it was exercising its option to purchase Merck’s interest in KBI which will be based in part on the value of Merck’s interest in Nexium and Prilosec. AstraZeneca will make a payment to Merck upon closing (which is expected to occur on June 30, 2014) of $327 million, reflecting an estimate of the fair value of Merck’s interest in Nexium and Prilosec. This portion of the exercise price is subject to a true-up in 2018 based on actual sales from closing in 2014 to June 2018. The exercise price will also include an additional amount equal to a multiple of ten times Merck’s average 1% annual profit allocation in the partnership for the three years prior to exercise. As a result of AstraZeneca exercising its option, as of July 1, 2014 (if the closing occurs on June 30, 2014 as expected), the Company will no longer record equity income from AZLP and supply sales to AZLP will terminate. In addition, the Company will recognize a pretax gain of approximately $700 million which will be primarily non-cash.
	Summarized financial information for AZLP is as follows:
		Three Months Ended
		March 31,
	($ in millions)	2014		2013
	Sales	$	1,082	$	1,158
	Materials and production costs	480		552
	Other expense, net	393		381
	Income before taxes (1)	$	209	$	225
	(1)	Merck’s partnership returns from AZLP are generally contractually determined as noted above and are not based on a percentage of income from AZLP, other than with respect to Merck’s 1% limited partnership interest.

Contingencies

Contingencies	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Contingencies	'
	Contingencies
	The Company is involved in various claims and legal proceedings of a nature considered normal to its business, including product liability, intellectual property, and commercial litigation, as well as additional matters such as antitrust actions and environmental matters. Except for the Vioxx Litigation (as defined below) for which a separate assessment is provided in this Note, in the opinion of the Company, it is unlikely that the resolution of these matters will be material to the Company’s financial position, results of operations or cash flows.
	Given the nature of the litigation discussed below, including the Vioxx Litigation, and the complexities involved in these matters, the Company is unable to reasonably estimate a possible loss or range of possible loss for such matters until the Company knows, among other factors, (i) what claims, if any, will survive dispositive motion practice, (ii) the extent of the claims, including the size of any potential class, particularly when damages are not specified or are indeterminate, (iii) how the discovery process will affect the litigation, (iv) the settlement posture of the other parties to the litigation and (v) any other factors that may have a material effect on the litigation.
	The Company records accruals for contingencies when it is probable that a liability has been incurred and the amount can be reasonably estimated. These accruals are adjusted periodically as assessments change or additional information becomes available. For product liability claims, a portion of the overall accrual is actuarially determined and considers such factors as past experience, number of claims reported and estimates of claims incurred but not yet reported. Individually significant contingent losses are accrued when probable and reasonably estimable. Legal defense costs expected to be incurred in connection with a loss contingency are accrued when probable and reasonably estimable.
	The Company’s decision to obtain insurance coverage is dependent on market conditions, including cost and availability, existing at the time such decisions are made. The Company has evaluated its risks and has determined that the cost of obtaining product liability insurance outweighs the likely benefits of the coverage that is available and, as such, has no insurance for certain product liabilities effective August 1, 2004.
	Vioxx Litigation
	Product Liability Lawsuits
	As previously disclosed, Merck is a defendant in approximately 90 federal and state lawsuits (the “Vioxx Product Liability Lawsuits”) alleging personal injury or economic loss as a result of the purchase or use of Vioxx. Most of the remaining cases are coordinated in a multidistrict litigation in the U.S. District Court for the Eastern District of Louisiana (the “Vioxx MDL”) before Judge Eldon E. Fallon.
	Merck has reached a resolution, approved by Judge Fallon, of all remaining federal court putative class actions that were brought on behalf of individual purchasers or users of Vioxx seeking reimbursement for alleged economic loss.
	Under the settlement, Merck will pay up to $23 million to pay all properly documented claims submitted by class members, approved attorneys’ fees and expenses, and approved settlement notice costs and certain other administrative expenses. The court entered an order approving the settlement on January 6, 2014. The deadline for members to submit claims under the settlement was May 6, 2014.
	Merck also settled a Missouri state court class action of plaintiffs who sought reimbursement for out-of-pocket costs relating to Vioxx. The Company established a reserve of $39 million in 2012 in connection with that settlement agreement, which is the minimum amount that the Company is required to pay under the agreement. The settlement was approved, and final judgment in the action has been entered. The court-approved process for class members to submit claims under the settlement closed in October 2013.
	In Indiana, plaintiffs filed a motion to certify a class of Indiana Vioxx purchasers in a case pending before the Circuit Court of Marion County, Indiana. That case has been dormant for several years.
	Merck is also a defendant in lawsuits brought by state Attorneys General of four states — Alaska, Mississippi, Montana and Utah. All of these actions are pending in the Vioxx MDL proceeding. These actions allege that Merck misrepresented the safety of Vioxx. These suits seek recovery for expenditures on Vioxx by government-funded health care programs, such as Medicaid, and/or penalties for alleged Consumer Fraud Act violations. In November 2013, the Circuit Court of Franklin County, Kentucky approved a settlement in an action filed by the Kentucky Attorney General, under which Merck agreed to pay Kentucky $25 million to resolve its lawsuit and the related appeals.
	Shareholder Lawsuits
	As previously disclosed, in addition to the Vioxx Product Liability Lawsuits, various putative class actions and individual lawsuits under federal securities laws and state laws have been filed against Merck and various current and former officers and directors (the “Vioxx Securities Lawsuits”). The Vioxx Securities Lawsuits are coordinated in a multidistrict litigation in the U.S. District Court for the District of New Jersey before Judge Stanley R. Chesler, and have been consolidated for all purposes. In August 2011, Judge Chesler granted in part and denied in part Merck’s motion to dismiss the Fifth Amended Class Action Complaint in the consolidated securities action. Among other things, the claims based on statements made on or after the voluntary withdrawal of Vioxx on September 30, 2004, have been dismissed. In October 2011, defendants answered the Fifth Amended Class Action Complaint. In April 2012, plaintiffs filed a motion for class certification and, in January 2013, Judge Chesler granted that motion. In March 2013, plaintiffs filed a motion for leave to amend their complaint to add certain allegations to expand the class period. In May 2013, the court denied plaintiffs’ motion for leave to amend their complaint to expand the class period, but granted plaintiffs’ leave to amend their complaint to add certain allegations within the existing class period. In June 2013, plaintiffs filed their Sixth Amended Class Action Complaint. In July 2013, defendants answered the Sixth Amended Class Action Complaint. Discovery has been completed and is now closed. Under the court’s scheduling order, dispositive motions have been fully briefed.
	As previously disclosed, several individual securities lawsuits filed by foreign institutional investors also are consolidated with the Vioxx Securities Lawsuits. In October 2011, plaintiffs filed amended complaints in each of the pending individual securities lawsuits. Also in October 2011, an individual securities lawsuit (the “KBC Lawsuit”) was filed in the District of New Jersey by several foreign institutional investors; that case is also consolidated with the Vioxx Securities Lawsuits. In January 2012, defendants filed motions to dismiss in one of the individual lawsuits (the “ABP Lawsuit”). Briefing on the motions to dismiss was completed in March 2012. In August 2012, Judge Chesler granted in part and denied in part the motions to dismiss the ABP Lawsuit. Among other things, certain alleged misstatements and omissions were dismissed as inactionable and all state law claims were dismissed in full. In September 2012, defendants answered the complaints in all individual actions other than the KBC Lawsuit; on the same day, defendants moved to dismiss the complaint in the KBC Lawsuit on statute of limitations grounds. In December 2012, Judge Chesler denied the motion to dismiss the KBC Lawsuit and, in January 2013, defendants answered the complaint in the KBC Lawsuit. Discovery has been completed and is now closed. Under the court’s scheduling order, dispositive motions have been fully briefed. In March 2014, two additional individual securities complaints were filed by institutional investors that opted out of the class action referred to above. The new complaints are substantially similar to the complaints in the other individual securities lawsuits.
	Insurance
	The Company has Directors and Officers insurance coverage applicable to the Vioxx Securities Lawsuits with remaining stated upper limits of approximately $165 million, which is currently being used to partially fund the Company’s legal fees. As a result of the previously disclosed insurance arbitration, additional insurance coverage for these claims should also be available, if needed, under upper-level excess policies that provide coverage for a variety of risks. There are disputes with the insurers about the availability of some or all of the Company’s insurance coverage for these claims and there are likely to be additional disputes. The amounts actually recovered under the policies discussed in this paragraph may be less than the stated upper limits.
	International Lawsuits
	As previously disclosed, in addition to the lawsuits discussed above, Merck has been named as a defendant in litigation relating to Vioxx in Brazil, Canada, Europe and Israel (collectively, the “Vioxx International Lawsuits”). As previously disclosed, the Company has entered into an agreement to resolve all claims related to Vioxx in Canada pursuant to which the Company will pay a minimum of approximately $21 million but not more than an aggregate maximum of approximately $36 million. The agreement has been approved by courts in Canada’s provinces.
	Reserves
	The Company believes that it has meritorious defenses to the remaining Vioxx Product Liability Lawsuits, Vioxx Securities Lawsuits and Vioxx International Lawsuits (collectively, the “Vioxx Litigation”) and will vigorously defend against them. In view of the inherent difficulty of predicting the outcome of litigation, particularly where there are many claimants and the claimants seek indeterminate damages, the Company is unable to predict the outcome of these matters and, at this time, cannot reasonably estimate the possible loss or range of loss with respect to the remaining Vioxx Litigation. The Company has established a reserve with respect to the Canadian settlement, certain other Vioxx Product Liability Lawsuits and other immaterial settlements related to certain Vioxx International Lawsuits. The Company also has an immaterial remaining reserve relating to the previously disclosed Vioxx investigation for the non-participating states with which litigation is continuing. The Company has established no other liability reserves with respect to the Vioxx Litigation. Unfavorable outcomes in the Vioxx Litigation could have a material adverse effect on the Company’s financial position, liquidity and results of operations.
	Other Product Liability Litigation
	Fosamax
	As previously disclosed, Merck is a defendant in product liability lawsuits in the United States involving Fosamax (the “Fosamax Litigation”). As of March 31, 2014, approximately 5,580 cases, which include approximately 5,850 plaintiff groups, had been filed and were pending against Merck in either federal or state court, including one case which seeks class action certification, as well as damages and/or medical monitoring. In approximately 1,150 of these actions, plaintiffs allege, among other things, that they have suffered osteonecrosis of the jaw (“ONJ”), generally subsequent to invasive dental procedures, such as tooth extraction or dental implants and/or delayed healing, in association with the use of Fosamax. In addition, plaintiffs in approximately 4,430 of these actions generally allege that they sustained femur fractures and/or other bone injuries (“Femur Fractures”) in association with the use of Fosamax.
	In December 2013, Merck reached an agreement in principle with the Plaintiffs’ Steering Committee (“PSC”) in the Fosamax ONJ MDL (as defined below) to resolve pending ONJ cases not on appeal in the Fosamax ONJ MDL and in the state courts for an aggregate amount of $27.7 million, which the Company recorded as a liability in the fourth quarter of 2013. Merck and the PSC subsequently formalized the terms of this agreement in a Master Settlement Agreement that was executed in April 2014. All of plaintiffs’ counsel have advised the Company that they intend to participate in the settlement plan. As a condition to the settlement, 100% of the state and federal ONJ plaintiffs must also agree to participate in the settlement plan. Merck has exercised its right to extend the deadline for plaintiffs to agree to participate to May 15, 2014. If 100% participation is not achieved, Merck has 45 days from the final date to determine whether it will terminate the agreement, or waive the 100% participation requirement and agree to a lesser funding amount for the settlement fund. Merck has also settled the four ONJ cases on appeal for approximately $3.5 million in the aggregate. These settlements have no effect on the cases alleging Femur Fractures discussed below.
	Cases Alleging ONJ and/or Other Jaw Related Injuries
	In August 2006, the Judicial Panel on Multidistrict Litigation (“JPML”) ordered that certain Fosamax product liability cases pending in federal courts nationwide should be transferred and consolidated into one multidistrict litigation (the “Fosamax ONJ MDL”) for coordinated pre-trial proceedings. The Fosamax ONJ MDL has been transferred to Judge John Keenan in the U.S. District Court for the Southern District of New York. As a result of the JPML order, approximately 860 of the cases are before Judge Keenan, although, as noted above, these cases are subject to the pending settlement.
	In addition, in July 2008, an application was made by the Atlantic County Superior Court of New Jersey requesting that all of the Fosamax cases pending in New Jersey be considered for mass tort designation and centralized management before one judge in New Jersey. In October 2008, the New Jersey Supreme Court ordered that all pending and future actions filed in New Jersey arising out of the use of Fosamax and seeking damages for existing dental and jaw-related injuries, including ONJ, but not solely seeking medical monitoring, be designated as a mass tort for centralized management purposes before Judge Carol E. Higbee in Atlantic County Superior Court. As of March 31, 2014, approximately 285 ONJ cases were pending against Merck in Atlantic County, New Jersey, although these cases are also subject to the pending settlement described above.
	Cases Alleging Femur Fractures
	In March 2011, Merck submitted a Motion to Transfer to the JPML seeking to have all federal cases alleging Femur Fractures consolidated into one multidistrict litigation for coordinated pre-trial proceedings. The Motion to Transfer was granted in May 2011, and all federal cases involving allegations of Femur Fracture have been or will be transferred to a multidistrict litigation in the District of New Jersey (the “Fosamax Femur Fracture MDL”). As a result of the JPML order, approximately 1,120 cases were pending in the Fosamax Femur Fracture MDL as of March 31, 2014. A Case Management Order was entered requiring the parties to review 33 cases. Judge Joel Pisano selected four cases from that group to be tried as the initial bellwether cases in the Fosamax Femur Fracture MDL. The first bellwether case, Glynn v. Merck, began on April 8, 2013, and the jury returned a verdict in Merck’s favor on April 29, 2013; in addition, on June 27, 2013, Judge Pisano granted Merck’s motion for judgment as a matter of law in the Glynn case and held that the plaintiff’s failure to warn claim was preempted by federal law. Judge Pisano set a May 5, 2014, trial date for the bellwether trial of a case in which the alleged injury took place after January 31, 2011. Following the completion of fact discovery, the court selected Sweet v. Merck as the next Fosamax Femur Fracture MDL case to be tried on May 5, 2014, but plaintiffs subsequently dismissed that case. As a result, the May 2014 trial date was withdrawn.
	In addition, Judge Pisano entered an order in August 2013 requiring plaintiffs in the Fosamax Femur Fracture MDL to show cause why those cases asserting claims for a femur fracture injury that took place prior to September 14, 2010, should not be dismissed based on the court’s preemption decision in the Glynn case. Plaintiffs filed their responses to the show cause order at the end of September 2013 and Merck filed its reply to those responses at the end of October 2013. A hearing on the show cause order was held in January 2014 and, on March 26, 2014, Judge Pisano issued an opinion finding that all claims of the approximately 650 plaintiffs who allegedly suffered injuries prior to September 14, 2010 were preempted and ordered that those cases be dismissed. The majority of those plaintiffs are appealing that ruling to the U.S. Court of Appeals for the Third Circuit.
	As of March 31, 2014, approximately 2,785 cases alleging Femur Fractures have been filed in New Jersey state court and are pending before Judge Higbee in Atlantic County Superior Court. The parties selected an initial group of 30 cases to be reviewed through fact discovery. Two additional groups of 50 cases each to be reviewed through fact discovery were selected in November 2013 and March 2014, respectively.
	As of March 31, 2014, approximately 525 cases alleging Femur Fractures have been filed in California state court. A petition was filed seeking to coordinate all Femur Fracture cases filed in California state court before a single judge in Orange County, California. The petition was granted and Judge Steven Perk is now presiding over the coordinated proceedings. In March 2014, Judge Perk directed that a group of 10 discovery pool cases be reviewed through fact discovery and scheduled dates in February, April and June 2015 for trials of three individual cases that will be selected from that group. The parties are expected to identify the initial set of cases that will be included in the discovery pool in May 2014.
	Additionally, there are six Femur Fracture cases pending in other state courts.
	Discovery is ongoing in the Fosamax Femur Fracture MDL and in state courts where Femur Fracture cases are pending and the Company intends to defend against these lawsuits.
	Januvia/Janumet
	As previously disclosed, Merck is a defendant in product liability lawsuits in the United States involving Januvia and/or Janumet. As of March 31, 2014, approximately 295 cases were served on, and are pending against, Merck alleging generally that use of Januvia and/or Janumet caused the development of pancreatic cancer. These complaints were filed in several different state and federal courts. Most of the claims are pending in a consolidated multidistrict litigation proceeding in the U.S. District Court for the Southern District of California called “In re Incretin-Based Therapies Products Liability Litigation.” That proceeding includes federal lawsuits alleging pancreatic cancer due to use of the following medicines: Januvia, Janumet, Byetta and Victoza, the latter two of which are products manufactured by other pharmaceutical companies. In addition to the cases noted above, the Company has agreed, as of March 31, 2014, to toll the statute of limitations for 11 additional claims. The Company intends to defend against these lawsuits.
	NuvaRing
	As previously disclosed, beginning in May 2007, a number of complaints were filed in various jurisdictions asserting claims against the Company’s subsidiaries Organon USA, Inc., Organon Pharmaceuticals USA, Inc., Organon International (collectively, “Organon”), and the Company arising from Organon’s marketing and sale of NuvaRing (the “NuvaRing Litigation”), a combined hormonal contraceptive vaginal ring. The plaintiffs contend that Organon and Schering-Plough, among other things, failed to adequately design and manufacture NuvaRing and failed to adequately warn of the alleged increased risk of venous thromboembolism (“VTE”) posed by NuvaRing, and/or downplayed the risk of VTE. The plaintiffs seek damages for injuries allegedly sustained from their product use, including some alleged deaths, heart attacks and strokes. The majority of the cases are currently pending in a federal multidistrict litigation (the “NuvaRing MDL”) venued in Missouri and in a coordinated proceeding in New Jersey state court.
	Merck and negotiating plaintiffs’ counsel have agreed to a settlement of the NuvaRing Litigation that is intended to resolve at least 95% of all cases filed as of February 7, 2014, and all unfiled claims under retainer by counsel prior to that date. Plaintiffs’ response to the courts’ census orders has disclosed approximately 1,405 of such unfiled claims. Merck has agreed to a lump total settlement of $100 million, provided there is participation in the settlement of at least 95% of plaintiffs and eligible claimants overall and in certain categories. The original deadline to opt into the settlement has been extended to May 9, 2014. The Company has certain insurance coverage available to it, which is currently being used to partially fund the Company’s legal fees. This insurance coverage will also be used to fund the settlement.
	As of March 31, 2014, there were approximately 1,935 NuvaRing cases (excluding unfiled cases). Of these cases, approximately 1,715 are or will be pending in the NuvaRing MDL in the U.S. District Court for the Eastern District of Missouri before Judge Rodney Sippel, and approximately 210 are pending in coordinated proceedings in the Bergen County Superior Court of New Jersey before Judge Brian R. Martinotti. Seven additional cases are pending in various other state courts, including cases in a coordinated state proceeding in the San Francisco Superior Court in California before Judge John E. Munter. Certain state court cases are scheduled for trial in 2014.
	Propecia/Proscar
	As previously disclosed, Merck is a defendant in product liability lawsuits in the United States involving Propecia and/or Proscar. As of March 31, 2014, approximately 1,190 lawsuits involving a total of approximately 1,450 plaintiffs (in a few instances spouses are joined as plaintiffs in the suits) who allege that they have experienced persistent sexual side effects following cessation of treatment with Propecia and/or Proscar have been filed against Merck. Approximately 35 of the plaintiffs also allege that Propecia or Proscar has caused or can cause prostate cancer or male breast cancer. The lawsuits have been filed in various federal courts and in state court in New Jersey. The federal lawsuits have been consolidated for pretrial purposes in a federal multidistrict litigation before Judge John Gleeson of the Eastern District of New York. The matters pending in state court in New Jersey have been consolidated before Judge Jessica Mayer in Middlesex County. In addition, there is one matter pending in federal court in Massachusetts and one matter pending in state court in St. Louis, Missouri. The Company intends to defend against these lawsuits.
	Vytorin/Zetia Litigation
	On November 14, 2013, two complaints were filed in the District of New Jersey against Merck as successor to Schering-Plough, and other defendants, by certain institutional investors who “opted-out” of the previously-disclosed and now settled ENHANCE securities class action against Schering-Plough. In addition, on January 14, 2014, two complaints were filed in the District of New Jersey against Merck and other defendants by certain institutional investors who “opted-out” of the similar Vytorin/Zetia securities class action against Merck. The “opt-out” complaints contain allegations similar to those made by plaintiffs in the settled class actions against Schering-Plough and Merck. On March 27, 2014, the court stayed all four “opt-out” cases pending a decision by the U.S. Supreme Court in Public Employees’ Retirement System of Mississippi v. Indymac MBS Inc. et al. The Company intends to move to dismiss these complaints and otherwise to defend itself in the litigation.
	Governmental Proceedings
	The Company’s subsidiaries in China have received and may continue to receive inquiries regarding their operations from various Chinese governmental agencies. Some of these inquiries may be related to matters involving other multinational pharmaceutical companies, as well as Chinese entities doing business with such companies. The Company’s policy is to cooperate with these authorities and to provide responses as appropriate.
	Patent Litigation
	From time to time, generic manufacturers of pharmaceutical products file Abbreviated New Drug Applications with the U.S. Food and Drug Administration (the “FDA”) seeking to market generic forms of the Company’s products prior to the expiration of relevant patents owned by the Company. To protect its patent rights, the Company may file patent infringement lawsuits against such generic companies. Certain products of the Company (or products marketed via agreements with other companies) currently involved in such patent infringement litigation in the United States include: Cancidas, Emend for Injection, Integrilin, Nexium, and NuvaRing. Similar lawsuits defending the Company’s patent rights may exist in other countries. The Company intends to vigorously defend its patents, which it believes are valid, against infringement by generic companies attempting to market products prior to the expiration of such patents. As with any litigation, there can be no assurance of the outcomes, which, if adverse, could result in significantly shortened periods of exclusivity for these products and, with respect to products acquired through mergers and acquisitions, potentially significant intangible asset impairment charges.
	Cancidas — In February 2014, a patent infringement lawsuit was filed in the United States against Xellia Pharmaceuticals ApS (“Xellia”) with respect to Xellia’s application to the FDA seeking pre-patent expiry approval to market a generic version of Cancidas. The lawsuit automatically stays FDA approval of Xellia’s application until July 2016 or until an adverse court decision, if any, whichever may occur earlier.
	Emend for Injection — In May 2012, a patent infringement lawsuit was filed in the United States against Sandoz Inc. (“Sandoz”) in respect of Sandoz’s application to the FDA seeking pre-patent expiry approval to market a generic version of Emend for Injection. The lawsuit automatically stays FDA approval of Sandoz’s application until July 2015 or until an adverse court decision, if any, whichever may occur earlier. In June 2012, a patent infringement lawsuit was filed in the United States against Accord Healthcare, Inc. US, Accord Healthcare, Inc. and Intas Pharmaceuticals Ltd (collectively, “Intas”) in respect of Intas’ application to the FDA seeking pre-patent expiry approval to market a generic version of Emend for Injection. The Company has agreed with Intas to stay the lawsuit pending the outcome of the lawsuit with Sandoz.
	Integrilin — In February 2009, a patent infringement lawsuit was filed (jointly with Millennium Pharmaceuticals, Inc.) in the United States against Teva Parenteral Medicines, Inc. (“TPM”) in respect of TPM’s application to the FDA seeking pre-patent expiry approval to sell a generic version of Integrilin. In October 2011, the parties entered into a settlement agreement allowing TPM to sell a generic version of Integrilin beginning June 2, 2015. In November 2012, a patent infringement lawsuit was filed against APP Pharmaceuticals, Inc. and Fresenius Kabi USA Inc. (collectively, “APP”) in respect of APP’s application to the FDA seeking pre-patent expiry approval to sell a generic version of Integrilin. In March 2013, the parties entered into a settlement agreement allowing APP to sell a generic version of Integrilin beginning June 2, 2015. In September 2013, a patent infringement lawsuit was filed against Ben Venue Laboratories d/b/a Bedford Laboratories (“Bedford”) in respect of Bedford’s application to the FDA seeking pre-patent expiry approval to sell a generic version of Integrilin. In February 2014, the parties entered into a settlement allowing Bedford to sell a generic version of Integrilin beginning June 2, 2015.
	Nexium — Patent infringement lawsuits were brought (jointly with AstraZeneca) in the United States against the following generic companies: Ranbaxy Laboratories Ltd., IVAX Pharmaceuticals, Inc. (later acquired by Teva Pharmaceuticals, Inc.), Dr. Reddy’s Laboratories, Sandoz, Lupin Ltd., Hetero Drugs Limited Unit III and Torrent Pharmaceuticals Ltd. in response to each generic company’s application seeking pre-patent expiry approval to sell a generic version of Nexium. Settlements have been reached in each of these lawsuits, the terms of which provide that the respective generic company may bring a generic version of esomeprazole product to market on May 27, 2014. In addition, a patent infringement lawsuit was also filed (jointly with AstraZeneca) in February 2010 in the United States against Sun Pharma Global Fze (“Sun Pharma”) in respect of its application to the FDA seeking pre-patent expiry approval to sell a generic version of Nexium IV, which lawsuit was settled with an agreement which provided that Sun Pharma was entitled to bring its generic esomeprazole IV product to market in the United States on January 1, 2014. A patent infringement lawsuit was also filed (jointly with AstraZeneca) in the United States against Hanmi USA, Inc. (“Hanmi”) related to its application to the FDA seeking pre-patent expiry approval to sell a different salt of esomeprazole than is found in Nexium (the “Hanmi Product”). In a May 2013 agreement, Hanmi conceded the validity and enforceability of the patents in the lawsuit. The parties also agreed that the Hanmi Product would not infringe those patents under the District Court’s December 2012 claim interpretation order, which AstraZeneca and KBI appealed. On December 19, 2013, the Court of Appeals for the Federal Circuit denied the appeal and affirmed the District of Court’s claim interpretation order. Hanmi has launched its esomeprazole product at risk. The Company continues to believe the court’s order was incorrect and is considering its options for further review.
	Additional patent infringement lawsuits have been filed (jointly with AstraZeneca) in the United States against Mylan Laboratories Limited (“Mylan Labs”), Actavis, Inc./Watson Pharma Company (collectively, “Actavis/Watson”), Wockhardt Limited and Wockhardt USA LLC (collectively, “Wockhardt”), Aurobindo Pharma Limited and Aurobindo Pharma USA Inc. (collectively, “Aurobindo”), and Kremers Urban Development Co. and Kremers Urban LLC (collectively, “Kremers”) related to their applications to the FDA seeking pre-patent expiry approval to sell generic versions of Nexium. The Mylan Labs, Actavis/Watson, Wockhardt, Aurobindo and Kremers applications to the FDA remain stayed until August 2014, October 2015, December 2015, April 2016 and April 2016, respectively, or until earlier adverse court decisions, if any, whichever may occur earlier.
	NuvaRing — In December 2013, the Company filed a lawsuit against Warner Chilcott Company LLC (“Warner Chilcott”) in the United States in respect of Warner Chilcott’s application to the FDA seeking pre-patent expiry approval to sell a generic version of NuvaRing.
	Patent Oppositions
	As previously disclosed, Ono Pharmaceutical Co. (“Ono”) has a European patent that broadly claims the use of an anti-PD-1 antibody, such as the Company’s immunotherapy, MK-3475, for the treatment of cancer. Ono has previously licensed its commercial rights to an anti-PD-1 antibody to Bristol-Myers Squibb (“BMS”) in certain markets. The Company believes that this patent is invalid and has filed an opposition in the European Patent Office (the “EPO”) seeking its revocation. The Opposition Division of the EPO has scheduled a hearing in June 2014. The hearing panel has issued a preliminary opinion that the claims in the patent are valid. The hearing panel usually renders a decision, which is subject to further appeal, at the close of a hearing. If the patent survives these proceedings with similar breadth, Merck can file actions seeking to revoke the patent in each relevant national court in Europe. Ono could file patent infringement actions against the Company in each relevant national court in Europe at or around the time the company launches MK-3475 (if approved). If a national court determines that the Company infringed a valid claim in Ono’s patent, Ono may be entitled to monetary damages, including royalties on future sales of MK-3475, and potentially could seek an injunction to prevent the Company from marketing MK-3475 in that country. On April 30, 2014, the Company opposed another European patent owned by BMS and Ono that it believes is invalid. This patent, if valid, broadly claims anti-PD-1 antibodies that could include MK-3475. In addition, Ono and BMS have similar and other patents and applications, which the Company is closely monitoring, pending in the United States, Japan and other countries. The Company is confident that it will be able to market MK-3475 in any country in which it is approved and that it will not be prevented from doing so by the Ono patent or any pending patent.
	Other Litigation
	There are various other pending legal proceedings involving the Company, principally product liability and intellectual property lawsuits. While it is not feasible to predict the outcome of such proceedings, in the opinion of the Company, either the likelihood of loss is remote or any reasonably possible loss associated with the resolution of such proceedings is not expected to be material to the Company’s financial position, results of operations or cash flows either individually or in the aggregate.
	Legal Defense Reserves
	Legal defense costs expected to be incurred in connection with a loss contingency are accrued when probable and reasonably estimable. Some of the significant factors considered in the review of these legal defense reserves are as follows: the actual costs incurred by the Company; the development of the Company’s legal defense strategy and structure in light of the scope of its litigation; the number of cases being brought against the Company; the costs and outcomes of completed trials and the most current information regarding anticipated timing, progression, and related costs of pre-trial activities and trials in the associated litigation. The amount of legal defense reserves as of March 31, 2014 and December 31, 2013 of approximately $190 million and $160 million, respectively, represents the Company’s best estimate of the minimum amount of defense costs to be incurred in connection with its outstanding litigation; however, events such as additional trials and other events that could arise in the course of its litigation could affect the ultimate amount of legal defense costs to be incurred by the Company. The Company will continue to monitor its legal defense costs and review the adequacy of the associated reserves and may determine to increase the reserves at any time in the future if, based upon the factors set forth, it believes it would be appropriate to do so.

Equity

Equity	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
Equity	'
	Equity
					Other			Retained			Accumulated								Non-			Total
		Common Stock			Paid-In			Earnings			Other			Treasury Stock					Controlling
					Capital						Comprehensive								Interests
	($ and shares in millions)	Shares	Par Value								Loss			Shares		Cost
	Balance at January 1, 2013	3,577	$	1,788	$	40,646		$	39,985		$	(4,682	)	550		$	(24,717	)	$	2,443		$	55,463
	Net income attributable to Merck & Co., Inc.	—	—		—			1,593			—			—		—			—			1,593
	Cash dividends declared on common stock	—	—		—			(1,306		)	—			—		—			—			(1,306		)
	Treasury stock shares purchased	—	—		—			—						14		(580		)	—			(580		)
	Share-based compensation plans and other	—	—		(35		)	—			—			(4	)	168			—			133
	Other comprehensive income	—	—		—			—			53			—					—			53
	Supera joint venture	—	—		116			—			—			—		—			112			228
	Net income attributable to noncontrolling interests	—	—		—			—			—			—		—			23			23
	Distributions attributable to noncontrolling interests	—	—		—			—			—			—		—			(1		)	(1		)
	Balance at March 31, 2013	3,577	$	1,788	$	40,727		$	40,272		$	(4,629	)	560		$	(25,129	)	$	2,577		$	55,606
	Balance at January 1, 2014	3,577	$	1,788	$	40,508		$	39,257		$	(2,197	)	650		$	(29,591	)	$	2,561		$	52,326
	Net income attributable to Merck & Co., Inc.	—	—		—			1,705			—			—		—			—			1,705
	Cash dividends declared on common stock	—	—		—			(1,301		)	—			—		—			—			(1,301		)
	Treasury stock shares purchased	—	—		—			—			—			21		(1,167		)	—			(1,167		)
	Share-based compensation plans and other	—	—		(58		)	—			—			(23	)	1,013			3			958
	Other comprehensive income	—	—		—			—			18			—		—			—			18
	Net income attributable to noncontrolling interests	—	—		—			—			—			—		—			26			26
	Distributions attributable to noncontrolling interests	—	—		—			—			—			—		—			(1		)	(1		)
	Balance at March 31, 2014	3,577	$	1,788	$	40,450		$	39,661		$	(2,179	)	648		$	(29,745	)	$	2,589		$	52,564
	In connection with the 1998 restructuring of Astra Merck Inc., the Company assumed $2.4 billion par value preferred stock with a dividend rate of 5% per annum, which is carried by KBI and included in Noncontrolling interests on the Consolidated Balance Sheet. As discussed in Note 7, AstraZeneca has exercised its option to acquire Merck’s interest in AZLP. Upon closing of that transaction, which is expected to occur on June 30, 2014, this preferred stock obligation will be retired.

ShareBased_Compensation_Plans

Share-Based Compensation Plans	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share-Based Compensation Plans	'
	Share-Based Compensation Plans
	The Company has share-based compensation plans under which the Company grants restricted stock units (“RSUs”) and performance share units (“PSUs”) to certain management level employees. In addition, employees, non-employee directors and employees of certain of the Company’s equity method investees may be granted options to purchase shares of Company common stock at the fair market value at the time of grant.
	The following table provides amounts of share-based compensation cost recorded in the Consolidated Statement of Income:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Pretax share-based compensation expense	$	56		$	67
	Income tax benefit	(17		)	(20		)
	Total share-based compensation expense, net of taxes	$	39		$	47
	During the first three months of 2014 and 2013, the Company granted 49 thousand RSUs with a weighted-average grant date fair value of $54.89 per RSU and 32 thousand RSUs with a weighted-average grant date fair value of $41.09 per RSU, respectively.
	During the first three months of 2014, the Company granted 80 thousand stock options with a weighted-average exercise price of $54.89 per option. During the first three months of 2013, the Company did not grant any stock options. The weighted-average fair value of options granted for the first three months of 2014 was $8.10 per option and was determined using the following assumptions:
		Three Months Ended March 31, 2014
	Expected dividend yield	4.2	%
	Risk-free interest rate	2.1	%
	Expected volatility	24.2	%
	Expected life (years)	7
	At March 31, 2014, there was $657 million of total pretax unrecognized compensation expense related to nonvested stock options, RSU and PSU awards which will be recognized over a weighted-average period of 2.3 years.
	The Company typically communicates the value of annual share-based compensation awards to employees during the first quarter, but the related share amounts are not established and communicated until early May. Therefore, while the number of RSU and stock option grants disclosed above do not reflect any amounts relating to the annual grants, share-based compensation costs for the first quarter of 2014 and 2013 and unrecognized compensation expense at March 31, 2014 reflect an impact relating to the awards communicated to employees. For segment reporting, share-based compensation costs are unallocated expenses.

Pension_and_Other_Postretireme

Pension and Other Postretirement Benefit Plans	3 Months Ended
	Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]	'
Pension and Other Postretirement Benefit Plans	'
	Pension and Other Postretirement Benefit Plans
	The Company has defined benefit pension plans covering eligible employees in the United States and in certain of its international subsidiaries. The net periodic benefit cost of such plans consisted of the following components:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Service cost	$	151		$	175
	Interest cost	175			166
	Expected return on plan assets	(300		)	(275		)
	Net amortization	27			84
	Termination benefits	14			2
	Curtailments	(9		)	—
		$	58		$	152
	The Company provides medical benefits, principally to its eligible U.S. retirees and similar benefits to their dependents, through its other postretirement benefit plans. The net cost of such plans consisted of the following components:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Service cost	$	19		$	24
	Interest cost	28			27
	Expected return on plan assets	(34		)	(31		)
	Net amortization	(18		)	(12		)
	Termination benefits	4			—
	Curtailments	(20		)	—
		$	(21	)	$	8
	In connection with restructuring actions (see Note 2), termination charges were recorded on pension and other postretirement benefit plans related to expanded eligibility for certain employees exiting Merck. Also, in connection with these restructuring actions, curtailments were recorded on pension and other postretirement benefit plans as reflected in the tables above.

Other_Income_Expense_Net

Other (Income) Expense, Net	3 Months Ended
	Mar. 31, 2014
Other Income and Expenses [Abstract]	'
Other (Income) Expense, Net	'
	Other (Income) Expense, Net
	Other (income) expense, net, consisted of:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Interest income	$	(61	)	$	(57	)
	Interest expense	188			184
	Exchange losses	34			212
	Other, net	(200		)	(57		)
		$	(39	)	$	282
	The lower exchange losses in the first quarter of 2014 as compared with the first quarter of 2013 are due primarily to a Venezuelan currency devaluation. In February 2013, the Venezuelan government devalued its currency (Bolívar Fuertes) from 4.30 VEF per U.S. dollar to 6.30 VEF per U.S. dollar. The Company recognized losses due to exchange of approximately $140 million in the first quarter of 2013 resulting from the remeasurement of the local monetary assets and liabilities at the new rate. Since January 2010, Venezuela has been designated hyperinflationary and, as a result, local foreign operations are remeasured in U.S. dollars with the impact recorded in results of operations. Other, net in the first quarter of 2014 includes a gain of $182 million on the divestiture of Sirna (see Note 3).
	Interest paid for the three months ended March 31, 2014 and 2013 was $168 million and $187 million, respectively.

Taxes_on_Income

Taxes on Income	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Taxes on Income	'
	Taxes on Income
	The effective income tax rates of 17.2% and (4.3)% for the first quarter of 2014 and 2013, respectively, reflect the impacts of acquisition-related costs and restructuring costs, partially offset by the beneficial impact of foreign earnings. In addition, the effective income tax rate for the first quarter of 2014 includes a benefit of approximately $300 million associated with a capital loss generated in the quarter associated with the sale of Sirna (see Note 3). The effective income tax rate for the first quarter of 2013 also reflects the favorable impact of various discrete items, including the impact of tax legislation enacted in the first quarter of 2013 that extended the R&D tax credit for both 2012 and 2013, a reduction in tax reserves upon expiration of applicable statute of limitations, as well as a benefit of approximately $160 million associated with the resolution of a previously disclosed federal income tax issue as discussed below.
	In 2010, the Internal Revenue Service (the “IRS”) finalized its examination of Schering-Plough’s 2003-2006 tax years. In this audit cycle, the Company reached an agreement with the IRS on an adjustment to income related to intercompany pricing matters. This income adjustment mostly reduced net operating loss carryforwards and other tax credit carryforwards. The Company’s reserves for uncertain tax positions were adequate to cover all adjustments related to this examination period. Additionally, as previously disclosed, the Company was seeking resolution of one issue raised during this examination through the IRS administrative appeals process. In the first quarter of 2013, the Company recorded an out-of-period net tax benefit of $160 million related to this issue, which was settled in the fourth quarter of 2012, with final resolution relating to interest owed being reached in the first quarter of 2013. The Company’s unrecognized tax benefits related to this issue exceeded the settlement amount. Management concluded that the exclusion of this benefit was not material to prior period financial statements.

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Earnings Per Share
	The calculations of earnings per share are as follows:
		Three Months Ended
		March 31,
	($ and shares in millions except per share amounts)	2014		2013
	Net income attributable to Merck & Co., Inc.	$	1,705	$	1,593
	Average common shares outstanding	2,934		3,022
	Common shares issuable (1)	37		31
	Average common shares outstanding assuming dilution	2,971		3,053
	Basic earnings per common share attributable to Merck & Co., Inc. common shareholders	$	0.58	$	0.53
	Earnings per common share assuming dilution attributable to Merck & Co., Inc. common shareholders	$	0.57	$	0.52
	(1)	Issuable primarily under share-based compensation plans.
	For the three months ended March 31, 2014 and 2013, 1 million and 86 million, respectively, of common shares issuable under share-based compensation plans were excluded from the computation of earnings per common share assuming dilution because the effect would have been antidilutive.

Other_Comprehensive_Income_Los

Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
Other Comprehensive Income (Loss)	'
	Other Comprehensive Income (Loss)
	Changes in AOCI by component are as follows:
		Three Months Ended March 31,
	($ in millions)	Derivatives				Investments				Employee				Cumulative			Accumulated Other
										Benefit				Translation			Comprehensive
										Plans				Adjustment			Income (Loss)
	Balance January 1, 2013, net of taxes	$	(97	)		$	73			$	(3,667	)		$	(991	)	$	(4,682	)
	Other comprehensive income (loss) before reclassification adjustments, pretax	349				36				133				(253		)	265
	Tax	(133		)		(12		)		(23		)		(92		)	(260		)
	Other comprehensive income (loss) before reclassification adjustments, net of taxes	216				24				110				(345		)	5
	Reclassification adjustments, pretax	32				(28		)		72				—			76
	Tax	(12		)		5				(21		)		—			(28		)
	Reclassification adjustments, net of taxes	20			(1)	(23		)	(2)	51			(3)	—			48
	Other comprehensive income (loss), net of taxes	236				1				161				(345		)	53
	Balance March 31, 2013, net of taxes	$	139			$	74			$	(3,506	)		$	(1,336	)	$	(4,629	)
	Balance January 1, 2014, net of taxes	$	132			$	54			$	(909	)		$	(1,474	)	$	(2,197	)
	Other comprehensive income (loss) before reclassification adjustments, pretax	(102		)		(5		)		(14		)		76			(45		)
	Tax	36				7				7				11			61
	Other comprehensive income (loss) before reclassification adjustments, net of taxes	(66		)		2				(7		)		87			16
	Reclassification adjustments, pretax	—				(5		)		9				—			4
	Tax	—				1				(3		)		—			(2		)
	Reclassification adjustments, net of taxes	—			(1)	(4		)	(2)	6			(3)	—			2
	Other comprehensive income (loss), net of taxes	(66		)		(2		)		(1		)		87			18
	Balance March 31, 2014, net of taxes	$	66			$	52			$	(910	)		$	(1,387	)	$	(2,179	)
	(1) Relates to foreign currency cash flow hedges that were reclassified from AOCI to Sales.
	(2) Represents net realized gains on the sales of available-for-sale investments that were reclassified from AOCI to Other (income) expense, net.
	(3) Includes net amortization of prior service cost and actuarial gains and losses included in net periodic benefit cost (see Note 11).

Segment_Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Segment Reporting	'
	Segment Reporting
	The Company’s operations are principally managed on a products basis and are comprised of four operating segments – Pharmaceutical, Animal Health, Consumer Care and Alliances (which includes revenue and equity income from the Company’s relationship with AZLP). The Animal Health, Consumer Care and Alliances segments are not material for separate reporting. The Pharmaceutical segment includes human health pharmaceutical and vaccine products marketed either directly by the Company or through joint ventures. Human health pharmaceutical products consist of therapeutic and preventive agents, generally sold by prescription, for the treatment of human disorders. The Company sells these human health pharmaceutical products primarily to drug wholesalers and retailers, hospitals, government agencies and managed health care providers such as health maintenance organizations, pharmacy benefit managers and other institutions. Vaccine products consist of preventive pediatric, adolescent and adult vaccines, primarily administered at physician offices. The Company sells these human health vaccines primarily to physicians, wholesalers, physician distributors and government entities. A large component of pediatric and adolescent vaccines is sold to the U.S. Centers for Disease Control and Prevention Vaccines for Children program, which is funded by the U.S. government. Additionally, the Company sells vaccines to the Federal government for placement into vaccine stockpiles. The Company also has animal health operations that discover, develop, manufacture and market animal health products, including vaccines, which the Company sells to veterinarians, distributors and animal producers. Additionally, the Company has consumer care operations that develop, manufacture and market over-the-counter, foot care and sun care products, which are sold through wholesale and retail drug, food chain and mass merchandiser outlets, as well as club stores and specialty channels. In May 2014, the Company announced that it had entered into an agreement to sell its Consumer Care business to Bayer (see Note 3).
	Sales of the Company’s products were as follows:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Primary Care and Women’s Health
	Cardiovascular
	Zetia	$	611		$	629
	Vytorin	361			394
	Diabetes
	Januvia	858			884
	Janumet	476			409
	General Medicine and Women’s Health
	NuvaRing	168			151
	Follistim AQ	110			122
	Dulera	102			68
	Implanon	102			84
	Hospital and Specialty
	Hepatitis
	PegIntron	112			126
	Victrelis	59			110
	HIV
	Isentress	390			362
	Hospital
	Cancidas	166			162
	Invanz	114			110
	Noxafil	74			65
	Bridion	73			63
	Primaxin	71			84
	Immunology
	Remicade	604			549
	Simponi	157			108
	Other
	Cosopt/Trusopt	99			105
	Oncology
	Emend	122			116
	Temodar	83			216
	Diversified Brands
	Respiratory
	Nasonex	312			385
	Singulair	271			337
	Clarinex	62			61
	Other
	Cozaar/Hyzaar	205			267
	Arcoxia	128			121
	Fosamax	123			137
	Propecia	74			68
	Zocor	64			82
	Remeron	50			52
	Vaccines (1)
	Gardasil	383			390
	ProQuad/M-M-R II/Varivax	280			272
	RotaTeq	169			162
	Zostavax	142			168
	Pneumovax 23	101			111
	Other pharmaceutical (2)	1,175			1,361
	Total Pharmaceutical segment sales	8,451			8,891
	Other segment sales (3)	1,540			1,712
	Total segment sales	9,991			10,603
	Other (4)	273			68
		$	10,264		$	10,671
	(1)	These amounts do not reflect sales of vaccines sold in most major European markets through the Company’s joint venture, Sanofi Pasteur MSD, the results of which are reflected in Equity income from affiliates. These amounts do, however, reflect supply sales to Sanofi Pasteur MSD.
(2)	Other pharmaceutical primarily reflects sales of other human health pharmaceutical products, including products within the franchises not listed separately.
(3)	Represents the non-reportable segments of Animal Health, Consumer Care and Alliances. The Alliances segment includes revenue from the Company’s relationship with AZLP.
(4)	Other revenues are primarily comprised of miscellaneous corporate revenues, third-party manufacturing sales, sales related to divested products or businesses and other supply sales not included in segment results. In January 2014, Merck received $232 million in connection with the sale of the U.S. marketing rights to Saphris (see Note 3). In October 2013, the Company divested a substantial portion of its third-party manufacturing sales (see Note 2).
A reconciliation of segment profits to Income before taxes is as follows:
	Three Months Ended
	March 31,
($ in millions)	2014			2013
Segment profits:
Pharmaceutical segment	$	5,197		$	5,345
Other segments	700			899
Total segment profits	5,897			6,244
Other profits (losses)	213			(14		)
Unallocated:
Interest income	61			57
Interest expense	(188		)	(184		)
Equity income from affiliates	55			(2		)
Depreciation and amortization	(620		)	(479		)
Research and development	(1,289		)	(1,663		)
Amortization of purchase accounting adjustments	(1,126		)	(1,184		)
Restructuring costs	(125		)	(119		)
Other unallocated, net	(787		)	(1,106		)
	$	2,091		$	1,550
Segment profits are comprised of segment sales less standard costs and certain operating expenses directly incurred by the segments. For internal management reporting presented to the chief operating decision maker, Merck does not allocate materials and production costs, other than standard costs, the majority of research and development expenses or general and administrative expenses, nor the cost of financing these activities. Separate divisions maintain responsibility for monitoring and managing these costs, including depreciation related to fixed assets utilized by these divisions and, therefore, they are not included in segment profits. In addition, costs related to restructuring activities, as well as the amortization of purchase accounting adjustments are not allocated to segments.
Other profits (losses) are primarily comprised of miscellaneous corporate profits (losses), as well as operating profits (losses) related to third-party manufacturing sales, divested products and other supply sales.
Other unallocated, net includes expenses from corporate and manufacturing cost centers, product intangible asset impairment charges, gains or losses on sales of businesses and other miscellaneous income or expense items.

Contingencies_Policies

Contingencies (Policies)	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Legal Costs, Policy	'
	Legal defense costs expected to be incurred in connection with a loss contingency are accrued when probable and reasonably estimable.

Restructuring_Tables

Restructuring (Tables)	3 Months Ended
	Mar. 31, 2014
Restructuring and Related Activities [Abstract]	'
Charges Related to Restructuring Program Activities by Type of Cost	'
	The following tables summarize the charges related to restructuring program activities by type of cost:
		Three Months Ended March 31, 2014
	($ in millions)	Separation			Accelerated			Other			Total
		Costs			Depreciation
	2013 Restructuring Program
	Materials and production	$	—		$	81		$	6		$	87
	Marketing and administrative	—			19			—			19
	Research and development	—			41			7			48
	Restructuring costs	25			—			(19		)	6
		25			141			(6		)	160
	Merger Restructuring Program
	Materials and production	—			68			(36		)	32
	Marketing and administrative	—			12			—			12
	Research and development	—			2			1			3
	Restructuring costs	29			—			90			119
		29			82			55			166
		$	54		$	223		$	49		$	326
		Three Months Ended March 31, 2013
	($ in millions)	Separation			Accelerated			Other			Total
		Costs			Depreciation
	Merger Restructuring Program
	Materials and production	$	—		$	31		$	9		$	40
	Marketing and administrative	—			15			—			15
	Research and development	—			15			—			15
	Restructuring costs	65			—			18			83
		65			61			27			153
	2008 Restructuring Program
	Materials and production	—			—			3			3
	Marketing and administrative	—			2			—			2
	Restructuring costs	32			—			4			36
		32			2			7			41
		$	97		$	63		$	34		$	194
Charges and Spending Relating to Restructuring Activities by Program	'
	The following table summarizes the charges and spending relating to restructuring activities by program for the three months ended March 31, 2014:
	($ in millions)	Separation			Accelerated			Other			Total
		Costs			Depreciation
	2013 Restructuring Program
	Restructuring reserves January 1, 2014	$	745		$	—		$	23		$	768
	Expense	25			141			(6		)	160
	(Payments) receipts, net	(235		)	—			(19		)	(254		)
	Non-cash activity	—			(141		)	19			(122		)
	Restructuring reserves March 31, 2014 (1)	$	535		$	—		$	17		$	552
	Merger Restructuring Program
	Restructuring reserves January 1, 2014	$	725		$	—		$	12		$	737
	Expense	29			82			55			166
	(Payments) receipts, net	(77		)	—			(35		)	(112		)
	Non-cash activity	—			(82		)	(21		)	(103		)
	Restructuring reserves March 31, 2014 (1)	$	677		$	—		$	11		$	688
	(1)	The cash outlays associated with the 2013 Restructuring Program are expected to be substantially completed by the end of 2015. The cash outlays associated with the Merger Restructuring Program were substantially completed by the end of 2013 with the exception of certain actions, principally manufacturing-related, which are expected to be substantially completed by 2016.

Acquisitions_Divestitures_Rese1

Acquisitions, Divestitures, Research Collaborations and License Agreements (Tables)	3 Months Ended
	Mar. 31, 2014
Business Combinations [Abstract]	'
Schedule of Assets and Liabilities of Merck Consumer Care as Held for Sale	'
	Information with respect to Consumer Care assets and liabilities held for sale is as follows:
	($ millions)	31-Mar-14
	Assets
	Accounts receivable, net	$	207
	Inventories	316
	Deferred income taxes and other current assets	48
	Property, plant and equipment, net	221
	Goodwill	137
	Other intangibles, net	2,194
	Other assets	66
		$	3,189
	Liabilities
	Trade accounts payable	$	101
	Accrued and other current liabilities	193
	Deferred income taxes	543
	Other noncurrent liabilities	11
		$	848

Financial_Instruments_Tables

Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Fair Value of Derivatives on a Gross Basis Segregated between those Derivatives that are Designated as Hedging Instruments and those that are Not Designated as Hedging Instruments	'
	Presented in the table below is the fair value of derivatives on a gross basis segregated between those derivatives that are designated as hedging instruments and those that are not designated as hedging instruments:
			31-Mar-14									31-Dec-13
			Fair Value of Derivative						U.S. Dollar			Fair Value of Derivative						U.S. Dollar
	($ in millions)	Balance Sheet Caption	Asset			Liability			Notional			Asset			Liability			Notional
	Derivatives Designated as Hedging Instruments
	Interest rate swap contracts (non-current)	Other assets	$	14		$	—		$	1,550		$	13		$	—		$	1,550
	Interest rate swap contracts (non-current)	Other noncurrent liabilities	—			22			2,000			—			25			2,000
	Foreign exchange contracts (current)	Deferred income taxes and other current assets	402			—			5,541			493			—			4,427
	Foreign exchange contracts (non-current)	Other assets	387			—			6,158			515			—			6,676
	Foreign exchange contracts (current)	Accrued and other current liabilities	—			10			1,245			—			19			1,659
	Foreign exchange contracts (non-current)	Other noncurrent liabilities	—			3			475			—			—			—
			$	803		$	35		$	16,969		$	1,021		$	44		$	16,312
	Derivatives Not Designated as Hedging Instruments
	Foreign exchange contracts (current)	Deferred income taxes and other current assets	$	74		$	—		$	7,161		$	69		$	—		$	5,705
	Foreign exchange contracts (current)	Accrued and other current liabilities	—			71			6,441			—			140			7,892
			$	74		$	71		$	13,602		$	69		$	140		$	13,597
			$	877		$	106		$	30,571		$	1,090		$	184		$	29,909
Information on Derivative Positions Subject to Master Netting Arrangements as if they were Presented on a Net Basis	'
	The following table provides information on the Company’s derivative positions subject to these master netting arrangements as if they were presented on a net basis, allowing for the right of offset by counterparty and cash collateral exchanged per the master agreements and related credit support annexes:
		31-Mar-14						31-Dec-13
	($ in millions)	Asset			Liability			Asset			Liability
	Gross amounts recognized in the consolidated balance sheet	$	877		$	106		$	1,090		$	184
	Gross amount subject to offset in master netting arrangements	(102		)	(102		)	(147		)	(147		)
	not offset in the consolidated balance sheet
	Cash collateral (received) posted	(478		)	—			(652		)	—
	Net amounts	$	297		$	4		$	291		$	37
Location and Pretax Gain or Loss Amounts for Derivatives that are: (i) Designated in a Fair Value Hedging Relationship, (ii) Designated in a Cash Flow Hedging Relationship, (iii) Designated in a Foreign Currency net Investment Hedging Relationship and (iv) Not Designated in a Hedging Relationship	'
	The table below provides information on the location and pretax gain or loss amounts for derivatives that are: (i) designated in a fair value hedging relationship, (ii) designated in a foreign currency cash flow hedging relationship, (iii) designated in a foreign currency net investment hedging relationship and (iv) not designated in a hedging relationship:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Derivatives designated in a fair value hedging relationship
	Interest rate swap contracts
	Amount of gain recognized in Other (income) expense, net on derivatives	$	(4	)	$	—
	Amount of loss recognized in Other (income) expense, net on hedged item	4			—
	Derivatives designated in foreign currency cash flow hedging relationships
	Foreign exchange contracts
	Amount of loss reclassified from AOCI to Sales	2			32
	Amount of loss (gain) recognized in OCI on derivatives	102			(349		)
	Derivatives designated in foreign currency net investment hedging relationships
	Foreign exchange contracts
	Amount of gain recognized in Other (income) expense, net on derivatives (1)	(2		)	(2		)
	Amount of loss (gain) recognized in OCI on derivatives	42			(180		)
	Derivatives not designated in a hedging relationship
	Foreign exchange contracts
	Amount of (gain) loss recognized in Other (income) expense, net on derivatives (2)	(82		)	24
	Amount of gain recognized in Sales	(1		)	(10		)
	(1) There was no ineffectiveness on the hedge. Represents the amount excluded from hedge effectiveness testing.
	(2) These derivative contracts mitigate changes in the value of remeasured foreign currency denominated monetary assets and liabilities attributable to changes in foreign currency exchange rates.
Information on Available-for-sale Investments	'
	Information on available-for-sale investments is as follows:
		31-Mar-14												31-Dec-13
		Fair			Amortized			Gross Unrealized						Fair			Amortized			Gross Unrealized
	($ in millions)	Value			Cost			Gains			Losses			Value			Cost			Gains		Losses
	Corporate notes and bonds	$	7,883		$	7,854		$	38		$	(9	)	$	7,054		$	7,037		$	32	$	(15	)
	Commercial paper	3,622			3,622			—			—			1,206			1,206			—		—
	U.S. government and agency securities	1,882			1,885			1			(4		)	1,236			1,239			1		(4		)
	Asset-backed securities	1,230			1,232			2			(4		)	1,300			1,303			1		(4		)
	Foreign government bonds	641			641			1			(1		)	125			126			—		(1		)
	Mortgage-backed securities	497			499			2			(4		)	476			479			2		(5		)
	Equity securities	637			587			78			(28		)	471			397			74		—
		$	16,392		$	16,320		$	122		$	(50	)	$	11,868		$	11,787		$	110	$	(29	)
Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	'
	Financial assets and liabilities measured at fair value on a recurring basis are summarized below:
		Fair Value Measurements Using												Fair Value Measurements Using
		Quoted Prices			Significant			Significant			Total			Quoted Prices			Significant			Significant		Total
		In Active			Other			Unobservable						In Active			Other			Unobservable
		Markets for			Observable			Inputs						Markets for			Observable			Inputs
		Identical Assets			Inputs			(Level 3)						Identical Assets			Inputs			(Level 3)
		(Level 1)			(Level 2)									(Level 1)			(Level 2)
	($ in millions)	31-Mar-14												31-Dec-13
	Assets
	Investments
	Corporate notes and bonds	$	—		$	7,883		$	—		$	7,883		$	—		$	7,054		$	—	$	7,054
	Commercial paper	—			3,622			—			3,622			—			1,206			—		1,206
	U.S. government and agency securities	—			1,882			—			1,882			—			1,236			—		1,236
	Asset-backed securities (1)	—			1,230			—			1,230			—			1,300			—		1,300
	Foreign government bonds	—			641			—			641			—			125			—		125
	Mortgage-backed securities (1)	—			497			—			497			—			476			—		476
	Equity securities	386			—			—			386			238			—			—		238
		386			15,755			—			16,141			238			11,397			—		11,635
	Other assets
	Securities held for employee compensation	195			56			—			251			186			47			—		233
	Derivative assets (2)
	Purchased currency options	—			734			—			734			—			868			—		868
	Forward exchange contracts	—			129			—			129			—			209			—		209
	Interest rate swaps	—			14			—			14			—			13			—		13
		—			877			—			877			—			1,090			—		1,090
	Total assets	$	581		$	16,688		$	—		$	17,269		$	424		$	12,534		$	—	$	12,958
	Liabilities
	Derivative liabilities (2)
	Forward exchange contracts	$	—		$	58		$	—		$	58		$	—		$	134		$	—	$	134
	Written currency options	—			26			—			26			—			25			—		25
	Interest rate swaps	—			22			—			22			—			25			—		25
	Total liabilities	$	—		$	106		$	—		$	106		$	—		$	184		$	—	$	184
	(1)	Primarily all of the asset-backed securities are highly-rated (Standard & Poor’s rating of AAA and Moody’s Investors Service rating of Aaa), secured primarily by credit card, auto loan, and home equity receivables, with weighted-average lives of primarily 5 years or less. Mortgage-backed securities represent AAA-rated securities issued or unconditionally guaranteed as to payment of principal and interest by U.S. government agencies.
	(2)	The fair value determination of derivatives includes the impact of the credit risk of counterparties to the derivatives and the Company’s own credit risk, the effects of which were not significant.

Inventories_Tables

Inventories (Tables)	3 Months Ended
	Mar. 31, 2014
Inventory Disclosure [Abstract]	'
Inventories	'
	Inventories consisted of:
	($ in millions)	31-Mar-14		31-Dec-13
	Finished goods	$	1,642	$	1,738
	Raw materials and work in process	5,889		5,894
	Supplies	222		225
	Total (approximates current cost)	7,753		7,857
	Increase to LIFO costs	116		73
		$	7,869	$	7,930
	Recognized as:
	Inventories	$	6,376	$	6,226
	Other assets	1,493		1,704

Joint_Ventures_and_Other_Equit1

Joint Ventures and Other Equity Method Affiliates (Tables)	3 Months Ended
	Mar. 31, 2014
Equity Method Investments and Joint Ventures [Abstract]	'
Equity Income from Affiliates	'
	Equity income from affiliates reflects the performance of the Company’s joint ventures and other equity method affiliates and was comprised of the following:
		Three Months Ended
		March 31,
	($ in millions)	2014		2013
	AstraZeneca LP	$	98	$	125
	Other (1)	26		8
		$	124	$	133
	(1)	Includes results from Sanofi Pasteur MSD.
Summarized Financial Information for AZLP	'
	Summarized financial information for AZLP is as follows:
		Three Months Ended
		March 31,
	($ in millions)	2014		2013
	Sales	$	1,082	$	1,158
	Materials and production costs	480		552
	Other expense, net	393		381
	Income before taxes (1)	$	209	$	225
	(1)	Merck’s partnership returns from AZLP are generally contractually determined as noted above and are not based on a percentage of income from AZLP, other than with respect to Merck’s 1% limited partnership interest.

Equity_Tables

Equity (Tables)	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
Shareholders' Equity	'
					Other			Retained			Accumulated								Non-			Total
		Common Stock			Paid-In			Earnings			Other			Treasury Stock					Controlling
					Capital						Comprehensive								Interests
	($ and shares in millions)	Shares	Par Value								Loss			Shares		Cost
	Balance at January 1, 2013	3,577	$	1,788	$	40,646		$	39,985		$	(4,682	)	550		$	(24,717	)	$	2,443		$	55,463
	Net income attributable to Merck & Co., Inc.	—	—		—			1,593			—			—		—			—			1,593
	Cash dividends declared on common stock	—	—		—			(1,306		)	—			—		—			—			(1,306		)
	Treasury stock shares purchased	—	—		—			—						14		(580		)	—			(580		)
	Share-based compensation plans and other	—	—		(35		)	—			—			(4	)	168			—			133
	Other comprehensive income	—	—		—			—			53			—					—			53
	Supera joint venture	—	—		116			—			—			—		—			112			228
	Net income attributable to noncontrolling interests	—	—		—			—			—			—		—			23			23
	Distributions attributable to noncontrolling interests	—	—		—			—			—			—		—			(1		)	(1		)
	Balance at March 31, 2013	3,577	$	1,788	$	40,727		$	40,272		$	(4,629	)	560		$	(25,129	)	$	2,577		$	55,606
	Balance at January 1, 2014	3,577	$	1,788	$	40,508		$	39,257		$	(2,197	)	650		$	(29,591	)	$	2,561		$	52,326
	Net income attributable to Merck & Co., Inc.	—	—		—			1,705			—			—		—			—			1,705
	Cash dividends declared on common stock	—	—		—			(1,301		)	—			—		—			—			(1,301		)
	Treasury stock shares purchased	—	—		—			—			—			21		(1,167		)	—			(1,167		)
	Share-based compensation plans and other	—	—		(58		)	—			—			(23	)	1,013			3			958
	Other comprehensive income	—	—		—			—			18			—		—			—			18
	Net income attributable to noncontrolling interests	—	—		—			—			—			—		—			26			26
	Distributions attributable to noncontrolling interests	—	—		—			—			—			—		—			(1		)	(1		)
	Balance at March 31, 2014	3,577	$	1,788	$	40,450		$	39,661		$	(2,179	)	648		$	(29,745	)	$	2,589		$	52,564

ShareBased_Compensation_Plans_

Share-Based Compensation Plans (Tables)	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Amounts of Share-Based Compensation Cost Recorded in Consolidated Statement of Income	'
	The following table provides amounts of share-based compensation cost recorded in the Consolidated Statement of Income:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Pretax share-based compensation expense	$	56		$	67
	Income tax benefit	(17		)	(20		)
	Total share-based compensation expense, net of taxes	$	39		$	47
Assumptions Used to Determine Weighted-Average Fair Value of Options Granted	'
	The weighted-average fair value of options granted for the first three months of 2014 was $8.10 per option and was determined using the following assumptions:
		Three Months Ended March 31, 2014
	Expected dividend yield	4.2	%
	Risk-free interest rate	2.1	%
	Expected volatility	24.2	%
	Expected life (years)	7

Pension_and_Other_Postretireme1

Pension and Other Postretirement Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2014
Pension Plans, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Components of Net Cost of Defined Benefit Plans	'
	The Company has defined benefit pension plans covering eligible employees in the United States and in certain of its international subsidiaries. The net periodic benefit cost of such plans consisted of the following components:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Service cost	$	151		$	175
	Interest cost	175			166
	Expected return on plan assets	(300		)	(275		)
	Net amortization	27			84
	Termination benefits	14			2
	Curtailments	(9		)	—
		$	58		$	152
Other Postretirement Benefit Plans, Defined Benefit [Member]	'
Defined Benefit Plan Disclosure [Line Items]	'
Components of Net Cost of Defined Benefit Plans	'
	The Company provides medical benefits, principally to its eligible U.S. retirees and similar benefits to their dependents, through its other postretirement benefit plans. The net cost of such plans consisted of the following components:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Service cost	$	19		$	24
	Interest cost	28			27
	Expected return on plan assets	(34		)	(31		)
	Net amortization	(18		)	(12		)
	Termination benefits	4			—
	Curtailments	(20		)	—
		$	(21	)	$	8

Other_Income_Expense_Net_Table

Other (Income) Expense, Net (Tables)	3 Months Ended
	Mar. 31, 2014
Other Income and Expenses [Abstract]	'
Other (Income) Expense, Net	'
	Other (income) expense, net, consisted of:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Interest income	$	(61	)	$	(57	)
	Interest expense	188			184
	Exchange losses	34			212
	Other, net	(200		)	(57		)
		$	(39	)	$	282

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Calculations of Earnings Per Share	'
	The calculations of earnings per share are as follows:
		Three Months Ended
		March 31,
	($ and shares in millions except per share amounts)	2014		2013
	Net income attributable to Merck & Co., Inc.	$	1,705	$	1,593
	Average common shares outstanding	2,934		3,022
	Common shares issuable (1)	37		31
	Average common shares outstanding assuming dilution	2,971		3,053
	Basic earnings per common share attributable to Merck & Co., Inc. common shareholders	$	0.58	$	0.53
	Earnings per common share assuming dilution attributable to Merck & Co., Inc. common shareholders	$	0.57	$	0.52
	(1)	Issuable primarily under share-based compensation plans.

Other_Comprehensive_Income_Los1

Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
Changes in AOCI by Component	'
	Changes in AOCI by component are as follows:
		Three Months Ended March 31,
	($ in millions)	Derivatives				Investments				Employee				Cumulative			Accumulated Other
										Benefit				Translation			Comprehensive
										Plans				Adjustment			Income (Loss)
	Balance January 1, 2013, net of taxes	$	(97	)		$	73			$	(3,667	)		$	(991	)	$	(4,682	)
	Other comprehensive income (loss) before reclassification adjustments, pretax	349				36				133				(253		)	265
	Tax	(133		)		(12		)		(23		)		(92		)	(260		)
	Other comprehensive income (loss) before reclassification adjustments, net of taxes	216				24				110				(345		)	5
	Reclassification adjustments, pretax	32				(28		)		72				—			76
	Tax	(12		)		5				(21		)		—			(28		)
	Reclassification adjustments, net of taxes	20			(1)	(23		)	(2)	51			(3)	—			48
	Other comprehensive income (loss), net of taxes	236				1				161				(345		)	53
	Balance March 31, 2013, net of taxes	$	139			$	74			$	(3,506	)		$	(1,336	)	$	(4,629	)
	Balance January 1, 2014, net of taxes	$	132			$	54			$	(909	)		$	(1,474	)	$	(2,197	)
	Other comprehensive income (loss) before reclassification adjustments, pretax	(102		)		(5		)		(14		)		76			(45		)
	Tax	36				7				7				11			61
	Other comprehensive income (loss) before reclassification adjustments, net of taxes	(66		)		2				(7		)		87			16
	Reclassification adjustments, pretax	—				(5		)		9				—			4
	Tax	—				1				(3		)		—			(2		)
	Reclassification adjustments, net of taxes	—			(1)	(4		)	(2)	6			(3)	—			2
	Other comprehensive income (loss), net of taxes	(66		)		(2		)		(1		)		87			18
	Balance March 31, 2014, net of taxes	$	66			$	52			$	(910	)		$	(1,387	)	$	(2,179	)
	(1) Relates to foreign currency cash flow hedges that were reclassified from AOCI to Sales.
	(2) Represents net realized gains on the sales of available-for-sale investments that were reclassified from AOCI to Other (income) expense, net.
	(3) Includes net amortization of prior service cost and actuarial gains and losses included in net periodic benefit cost (see Note 11).

Segment_Reporting_Tables

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Sales of Company's Products	'
	Sales of the Company’s products were as follows:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Primary Care and Women’s Health
	Cardiovascular
	Zetia	$	611		$	629
	Vytorin	361			394
	Diabetes
	Januvia	858			884
	Janumet	476			409
	General Medicine and Women’s Health
	NuvaRing	168			151
	Follistim AQ	110			122
	Dulera	102			68
	Implanon	102			84
	Hospital and Specialty
	Hepatitis
	PegIntron	112			126
	Victrelis	59			110
	HIV
	Isentress	390			362
	Hospital
	Cancidas	166			162
	Invanz	114			110
	Noxafil	74			65
	Bridion	73			63
	Primaxin	71			84
	Immunology
	Remicade	604			549
	Simponi	157			108
	Other
	Cosopt/Trusopt	99			105
	Oncology
	Emend	122			116
	Temodar	83			216
	Diversified Brands
	Respiratory
	Nasonex	312			385
	Singulair	271			337
	Clarinex	62			61
	Other
	Cozaar/Hyzaar	205			267
	Arcoxia	128			121
	Fosamax	123			137
	Propecia	74			68
	Zocor	64			82
	Remeron	50			52
	Vaccines (1)
	Gardasil	383			390
	ProQuad/M-M-R II/Varivax	280			272
	RotaTeq	169			162
	Zostavax	142			168
	Pneumovax 23	101			111
	Other pharmaceutical (2)	1,175			1,361
	Total Pharmaceutical segment sales	8,451			8,891
	Other segment sales (3)	1,540			1,712
	Total segment sales	9,991			10,603
	Other (4)	273			68
		$	10,264		$	10,671
	(1)	These amounts do not reflect sales of vaccines sold in most major European markets through the Company’s joint venture, Sanofi Pasteur MSD, the results of which are reflected in Equity income from affiliates. These amounts do, however, reflect supply sales to Sanofi Pasteur MSD.
	(2)	Other pharmaceutical primarily reflects sales of other human health pharmaceutical products, including products within the franchises not listed separately.
	(3)	Represents the non-reportable segments of Animal Health, Consumer Care and Alliances. The Alliances segment includes revenue from the Company’s relationship with AZLP.
(4)	Other revenues are primarily comprised of miscellaneous corporate revenues, third-party manufacturing sales, sales related to divested products or businesses and other supply sales not included in segment results. In January 2014, Merck received $232 million in connection with the sale of the U.S. marketing rights to Saphris (see Note 3). In October 2013, the Company divested a substantial portion of its third-party manufacturing sales (see Note 2).
Reconciliation of Segment Profits to Income Before Taxes	'
	A reconciliation of segment profits to Income before taxes is as follows:
		Three Months Ended
		March 31,
	($ in millions)	2014			2013
	Segment profits:
	Pharmaceutical segment	$	5,197		$	5,345
	Other segments	700			899
	Total segment profits	5,897			6,244
	Other profits (losses)	213			(14		)
	Unallocated:
	Interest income	61			57
	Interest expense	(188		)	(184		)
	Equity income from affiliates	55			(2		)
	Depreciation and amortization	(620		)	(479		)
	Research and development	(1,289		)	(1,663		)
	Amortization of purchase accounting adjustments	(1,126		)	(1,184		)
	Restructuring costs	(125		)	(119		)
	Other unallocated, net	(787		)	(1,106		)
		$	2,091		$	1,550

Restructuring_Textual_Detail

Restructuring - Textual (Detail) (USD $)

3 Months Ended

1 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

51 Months Ended

3 Months Ended

1 Months Ended

3 Months Ended

12 Months Ended

Mar. 31, 2014

Mar. 31, 2013

Oct. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Jan. 31, 2014

Dec. 31, 2013

Dec. 31, 2013

2013 Restructuring Program [Member]

2013 Restructuring Program [Member]

2013 Restructuring Program [Member]

Merger Restructuring Program [Member]

Merger Restructuring Program [Member]

Merger Restructuring Program [Member]

2008 Restructuring Program [Member]

Minimum [Member]

Minimum [Member]

Maximum [Member]

Maximum [Member]

API manufacturing business [Member]

API manufacturing business [Member]

API manufacturing business [Member]

position

position

position

position

position

position

position

2013 Restructuring Program [Member]

Merger Restructuring Program [Member]

2013 Restructuring Program [Member]

Merger Restructuring Program [Member]

Merger Restructuring Program [Member]

Merger Restructuring Program [Member]

Merger Restructuring Program [Member]

Restructuring Cost and Reserve [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total number of positions expected to be eliminated

'

'

8,500

'

'

'

'

'

'

'

'

'

'

'

'

'

Total pretax restructuring costs

$326,000,000

$194,000,000

'

$160,000,000

'

$166,000,000

$153,000,000

'

$41,000,000

'

'

'

'

'

'

'

Expected cumulative restructuring costs, pretax

'

'

'

'

'

'

'

'

'

2,500,000,000

7,400,000,000

3,000,000,000

7,700,000,000

'

'

'

Cumulative restructuring costs incurred to date since program inception

'

'

'

'

1,400,000,000

'

'

7,300,000,000

'

'

'

'

'

'

'

'

Positions eliminated since inception of program

'

'

'

2,760

2,760

27,240

'

27,240

'

'

'

'

'

'

'

'

Remaining positions expected to be eliminated

'

'

'

'

'

5,600

'

5,600

'

'

'

'

'

'

'

'

Percentage estimate of cumulative pretax costs that will result in cash outlays (primarily from employee separation expense)

'

'

'

66.67%

'

66.67%

'

'

'

'

'

'

'

'

'

'

Percentage estimate of cumulative pretax costs that will be non-cash (primarily from accelerated depreciation of facilities)

'

'

'

33.33%

'

33.33%

'

'

'

'

'

'

'

'

'

'

Number of positions eliminated

'

'

'

1,220

'

360

740

'

50

'

'

'

'

'

'

'

Proceeds from divestiture of businesses

'

'

'

'

'

'

'

'

'

'

'

'

'

533,000,000

172,000,000

705,000,000

Noncash or part noncash divestiture, amount of consideration received

$172,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

$198,000,000

'

Restructuring_Charges_Related_

Restructuring - Charges Related to Restructuring Program Activities by Type of Cost (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	$3,903	$3,959
Marketing and administrative	2,734	2,987
Research and development	1,574	1,907
Restructuring costs	125	119
Total pretax restructuring costs	326	194
2013 Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	87	'
Marketing and administrative	19	'
Research and development	48	'
Restructuring costs	6	'
Total pretax restructuring costs	160	'
Merger Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	32	40
Marketing and administrative	12	15
Research and development	3	15
Restructuring costs	119	83
Total pretax restructuring costs	166	153
2008 Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	'	3
Marketing and administrative	'	2
Restructuring costs	'	36
Total pretax restructuring costs	'	41
Separation Costs [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Total pretax restructuring costs	54	97
Separation Costs [Member] | 2013 Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	'	'
Marketing and administrative	'	'
Research and development	'	'
Restructuring costs	25	'
Total pretax restructuring costs	25	'
Separation Costs [Member] | Merger Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	'	'
Marketing and administrative	'	'
Research and development	'	'
Restructuring costs	29	65
Total pretax restructuring costs	29	65
Separation Costs [Member] | 2008 Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	'	'
Marketing and administrative	'	'
Restructuring costs	'	32
Total pretax restructuring costs	'	32
Accelerated Depreciation [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Total pretax restructuring costs	223	63
Accelerated Depreciation [Member] | 2013 Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	81	'
Marketing and administrative	19	'
Research and development	41	'
Restructuring costs	'	'
Total pretax restructuring costs	141	'
Accelerated Depreciation [Member] | Merger Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	68	31
Marketing and administrative	12	15
Research and development	2	15
Restructuring costs	'	'
Total pretax restructuring costs	82	61
Accelerated Depreciation [Member] | 2008 Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	'	0
Marketing and administrative	'	2
Restructuring costs	'	'
Total pretax restructuring costs	'	2
Other [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Total pretax restructuring costs	49	34
Other [Member] | 2013 Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	6	'
Marketing and administrative	'	'
Research and development	7	'
Restructuring costs	-19	'
Total pretax restructuring costs	-6	'
Other [Member] | Merger Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	-36	9
Marketing and administrative	'	0
Research and development	1	0
Restructuring costs	90	18
Total pretax restructuring costs	55	27
Other [Member] | 2008 Restructuring Program [Member]	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Materials and production	'	3
Marketing and administrative	'	0
Restructuring costs	'	4
Total pretax restructuring costs	'	$7

Restructuring_Charges_and_Spen

Restructuring - Charges and Spending Relating to Restructuring Activities by Program (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Restructuring Reserve [Roll Forward]	'		'
Expense	$326		$194
2013 Restructuring Program [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Restructuring reserve, beginning balance	768		'
Expense	160		'
(Payments) receipts, net	-254		'
Non-cash activity	-122		'
Restructuring reserve, ending balance	552	[1]	'
Merger Restructuring Program [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Restructuring reserve, beginning balance	737		'
Expense	166		153
(Payments) receipts, net	-112		'
Non-cash activity	-103		'
Restructuring reserve, ending balance	688	[1]	'
Separation Costs [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Expense	54		97
Separation Costs [Member] | 2013 Restructuring Program [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Restructuring reserve, beginning balance	745		'
Expense	25		'
(Payments) receipts, net	-235		'
Non-cash activity	0		'
Restructuring reserve, ending balance	535	[1]	'
Separation Costs [Member] | Merger Restructuring Program [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Restructuring reserve, beginning balance	725		'
Expense	29		65
(Payments) receipts, net	-77		'
Non-cash activity	0		'
Restructuring reserve, ending balance	677	[1]	'
Accelerated Depreciation [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Expense	223		63
Accelerated Depreciation [Member] | 2013 Restructuring Program [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Restructuring reserve, beginning balance	0		'
Expense	141		'
(Payments) receipts, net	0		'
Non-cash activity	-141		'
Restructuring reserve, ending balance	0	[1]	'
Accelerated Depreciation [Member] | Merger Restructuring Program [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Restructuring reserve, beginning balance	0		'
Expense	82		61
(Payments) receipts, net	0		'
Non-cash activity	-82		'
Restructuring reserve, ending balance	0	[1]	'
Other [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Expense	49		34
Other [Member] | 2013 Restructuring Program [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Restructuring reserve, beginning balance	23		'
Expense	-6		'
(Payments) receipts, net	-19		'
Non-cash activity	19		'
Restructuring reserve, ending balance	17	[1]	'
Other [Member] | Merger Restructuring Program [Member]	'		'
Restructuring Reserve [Roll Forward]	'		'
Restructuring reserve, beginning balance	12		'
Expense	55		27
(Payments) receipts, net	-35		'
Non-cash activity	-21		'
Restructuring reserve, ending balance	$11	[1]	'
[1]	The cash outlays associated with the 2013 Restructuring Program are expected to be substantially completed by the end of 2015. The cash outlays associated with the Merger Restructuring Program were substantially completed by the end of 2013 with the exception of certain actions, principally manufacturing-related, which are expected to be substantially completed by 2016.

Acquisitions_Divestitures_Rese2

Acquisitions, Divestitures, Research Collaborations and License Agreements - Textual (Detail) (USD $)	3 Months Ended				1 Months Ended		3 Months Ended		3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014	Apr. 30, 2013	Mar. 31, 2014	Dec. 31, 2013	Feb. 28, 2013	Mar. 31, 2014
				Merck [Member]	Pfizer [Member]	Pfizer [Member]	Supera [Member]	Supera [Member]	Saphris/Sycrest [Member]
Business Acquisition [Line Items]	'	'	'	'	'	'	'	'	'
Proceeds from sale of intangible assets	'	'	'	'	'	'	'	'	$232
Cash proceeds from sale of technology	25	'	'	'	'	'	'	'	'
Shares received in consideration for sale of asset	2,520,044	'	'	'	'	'	'	'	'
Percentage of shares received from sale of technology	85.00%	'	'	'	'	'	'	'	'
Value of shares received to date from sale of technology	172	'	'	'	'	'	'	'	'
Percentage of shares to be received in the future from sale of technology	0.15	'	'	'	'	'	'	'	'
Gain on disposition of technology assets	182	'	'	'	'	'	'	'	'
Tax benefit recorded from sale of technology	300	'	'	'	'	'	'	'	'
Upfront and milestone payments	'	60	'	'	'	'	'	'	'
Percentage share of potential revenues and certain costs	'	'	'	60.00%	'	40.00%	'	'	'
Length of time to give notice to terminate the agreement	'	'	'	'	'12 months	'	'	'	'
Controlling interest of ownership in joint venture	'	'	'	'	'	'	'	51.00%	'
Non-controlling interest of ownership in joint venture	'	'	'	'	'	'	'	49.00%	'
Business Acquisition, Purchase Price Allocation, Currently marketed products	'	'	'	'	'	'	'	89	'
Business Acquisition, Purchase Price Allocation, In-process research and development	'	'	'	'	'	'	'	100	'
Goodwill	12,120	'	12,301	'	'	'	'	103	'
Business Acquisition, Purchase Price Allocation, Deferred tax liabilities	'	'	'	'	'	'	'	64	'
Business Acquisition, Purchase Price Allocation, Increases to Noncontrolling interests	'	'	'	'	'	'	'	112	'
Business Combination Acquisition of Less than 100 Percent Controlling Interest Fair Value	'	'	'	'	'	'	'	116	'
Intangible asset impairment charges related to IPR&D	'	'	'	'	'	'	$15	'	'
Extended period of marketing rights	'15 years	'	'	'	'	'	'	'	'

Acquisitions_Divestitures_Rese3

Acquisitions, Divestitures, Research Collaborations and License Agreements - Merck Consumer Care (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	31-May-14	31-May-14	31-May-14	31-May-14
			Consumer Care [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]	Subsequent Event [Member]
					Consumer Care [Member]	Minimum [Member]	Maximum [Member]
						Consumer Care [Member]	Consumer Care [Member]
Business Acquisition [Line Items]	'	'	'	'	'	'	'
Sale price for divestiture of business	'	'	'	'	$14,200,000,000	'	'
Future upfront payment for collaboration rights	'	'	'	1,000,000,000	'	'	'
Expected after tax proceeds from divestiture of business	'	'	'	'	'	8,000,000,000	9,000,000,000
Assets of Disposal Group, Including Discontinued Operation [Abstract]	'	'	'	'	'	'	'
Accounts receivable, net	'	'	207,000,000	'	'	'	'
Inventories	'	'	316,000,000	'	'	'	'
Deferred income taxes and other current assets	'	'	48,000,000	'	'	'	'
Property, plant and equipment, net	'	'	221,000,000	'	'	'	'
Goodwill	'	'	137,000,000	'	'	'	'
Other intangibles, net	'	'	2,194,000,000	'	'	'	'
Other assets	'	'	66,000,000	'	'	'	'
Assets of Disposal Group, Including Discontinued Operation, Current	3,224,000,000	26,000,000	3,189,000,000	'	'	'	'
Liabilities of Disposal Group, Including Discontinued Operation [Abstract]	'	'	'	'	'	'	'
Trade accounts payable	'	'	101,000,000	'	'	'	'
Accrued and other current liabilities	'	'	193,000,000	'	'	'	'
Deferred income taxes	'	'	543,000,000	'	'	'	'
Other noncurrent liabilities	'	'	11,000,000	'	'	'	'
Liabilities of Disposal Group, Including Discontinued Operation, Current	$848,000,000	$0	$848,000,000	'	'	'	'

Financial_Instruments_Textual_

Financial Instruments - Textual (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012
	Interest_Rate_Swap
Derivative [Line Items]	'	'	'	'
Maximum planning cycle of third-party sales hedges	'3 years	'	'	'
Maximum average period of maturities of contracts in years	'1 year	'	'	'
Pretax gains (losses) from euro-denominated notes included in cumulative translation adjustments	$12,000,000	$78,000,000	'	'
Interest rate swaps outstanding	15	'	'	'
Derivative, Notional Amount	30,571,000,000	'	29,909,000,000	'
Pretax net unrealized gains on derivatives maturing within next 12 months estimated to be reclassified from AOCI to sales	62,000,000	'	'	'
Available-for-sale debt securities included in Short-term investments	4,700,000,000	'	'	'
Available-for-sale debt securities maturing after one year through five years	10,300,000,000	'	'	'
Cash and cash equivalents	15,828,000,000	13,024,000,000	15,621,000,000	13,451,000,000
Cash equivalents	14,700,000,000	'	'	'
Fair value of loans payable and long-term debt, including current portion	28,900,000,000	'	25,500,000,000	'
Carrying value of loans payable and long-term debt, including current portion	28,100,000,000	'	25,100,000,000	'
Accounts receivable classified in Other assets	275,000,000	'	275,000,000	'
Accounts receivable outstanding for more than one year	180,000,000	'	'	'
Cash collateral received from counterparties	478,000,000	'	652,000,000	'
Greece, Italy, Spain and Portugal [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Accounts receivable in Greece, Italy, Spain and Portugal	940,000,000	'	'	'
Percentage of total accounts receivable outstanding for more than one year that relates to Greece, Italy, Spain and Portugal	50.00%	'	'	'
Greece, Italy, Spain and Portugal [Member] | Hospital and public sector [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Accounts receivable in Greece, Italy, Spain and Portugal	610,000,000	'	'	'
Greece [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Percentage of total hospital and public sector accounts receivable in Greece, Italy, Spain and Portugal in the aggregate that relate to specified country	11.00%	'	'	'
Italy [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Percentage of total hospital and public sector accounts receivable in Greece, Italy, Spain and Portugal in the aggregate that relate to specified country	45.00%	'	'	'
Spain [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Percentage of total hospital and public sector accounts receivable in Greece, Italy, Spain and Portugal in the aggregate that relate to specified country	33.00%	'	'	'
Portugal [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Percentage of total hospital and public sector accounts receivable in Greece, Italy, Spain and Portugal in the aggregate that relate to specified country	11.00%	'	'	'
5.00% Notes Due 2019 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Interest rate swaps outstanding	3	'	'	'
0.70% Notes Due 2016 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Interest rate swaps outstanding	4	'	'	'
Due 2018 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Interest rate swaps outstanding	4	'	'	'
6.00% Notes Due 2017 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Interest rate swaps outstanding	4	'	'	'
0.70% Notes Due 2016 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	0.70%	'	'	'
1.30% Notes Due 2018 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	1.30%	'	'	'
6.00% Notes Due 2017 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	6.00%	'	'	'
5.00% Notes Due 2019 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Debt Instrument, Interest Rate, Stated Percentage	5.00%	'	'	'
$150 Million Notional Amount [Member] | 5.00% Notes Due 2019 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Interest rate swaps outstanding	1	'	'	'
Interest Rate Swap [Member] | 0.70% Notes Due 2016 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Derivative, Notional Amount	250,000,000	'	'	'
Interest Rate Swap [Member] | 1.30% Notes Due 2018 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Derivative, Notional Amount	250,000,000	'	'	'
Interest Rate Swap [Member] | $150 Million Notional Amount [Member] | 5.00% Notes Due 2019 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Derivative, Notional Amount	150,000,000	'	'	'
Interest Rate Swap [Member] | $200 Million Notional Amounts [Member] | 5.00% Notes Due 2019 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Derivative, Notional Amount	200,000,000	'	'	'
Interest Rate Swap [Member] | $200 Million Notional Amounts [Member] | 6.00% Notes Due 2017 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Derivative, Notional Amount	200,000,000	'	'	'
Interest Rate Swap [Member] | $250 Million Notional Amounts [Member] | 6.00% Notes Due 2017 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Derivative, Notional Amount	250,000,000	'	'	'
Interest Rate Swap [Member] | $300 Million Notional Amount [Member] | 6.00% Notes Due 2017 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Derivative, Notional Amount	300,000,000	'	'	'
$300 Million Notional Amount [Member] | 6.00% Notes Due 2017 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Interest rate swaps outstanding	1	'	'	'
$250 Million Notional Amounts [Member] | 6.00% Notes Due 2017 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Interest rate swaps outstanding	2	'	'	'
$200 Million Notional Amounts [Member] | 5.00% Notes Due 2019 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Interest rate swaps outstanding	2	'	'	'
$200 Million Notional Amounts [Member] | 6.00% Notes Due 2017 [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Interest rate swaps outstanding	1	'	'	'
Significant Unobservable Inputs (Level 3) [Member]	'	'	'	'
Derivative [Line Items]	'	'	'	'
Business Combination, Contingent Consideration, Liability	$71,000,000	'	$69,000,000	'

Financial_Instruments_Fair_Val

Financial Instruments - Fair Value of Derivatives Segregated between those Derivatives that are Designated as Hedging Instruments and those that are Not Designated as Hedging Instruments (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	$877,000,000	$1,090,000,000
Fair Value of Derivative, Liability	106,000,000	184,000,000
U.S. Dollar Notional	30,571,000,000	29,909,000,000
Derivatives Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	803,000,000	1,021,000,000
Fair Value of Derivative, Liability	35,000,000	44,000,000
U.S. Dollar Notional	16,969,000,000	16,312,000,000
Derivatives Not Designated as Hedging Instruments [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	74,000,000	69,000,000
Fair Value of Derivative, Liability	71,000,000	140,000,000
U.S. Dollar Notional	13,602,000,000	13,597,000,000
Interest Rate Swap [Member] | Derivatives Designated as Hedging Instruments [Member] | Other assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	14,000,000	13,000,000
Fair Value of Derivative, Liability	'	'
U.S. Dollar Notional	1,550,000,000	1,550,000,000
Interest Rate Swap [Member] | Derivatives Designated as Hedging Instruments [Member] | Deferred Income Taxes And Noncurrent Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	'	'
Fair Value of Derivative, Liability	22,000,000	25,000,000
U.S. Dollar Notional	2,000,000,000	2,000,000,000
Foreign Exchange Contracts [Member] | Derivatives Designated as Hedging Instruments [Member] | Deferred income taxes and other current assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	402,000,000	493,000,000
Fair Value of Derivative, Liability	'	'
U.S. Dollar Notional	5,541,000,000	4,427,000,000
Foreign Exchange Contracts [Member] | Derivatives Designated as Hedging Instruments [Member] | Other assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	387,000,000	515,000,000
Fair Value of Derivative, Liability	'	'
U.S. Dollar Notional	6,158,000,000	6,676,000,000
Foreign Exchange Contracts [Member] | Derivatives Designated as Hedging Instruments [Member] | Accrued and other current liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	'	'
Fair Value of Derivative, Liability	10,000,000	19,000,000
U.S. Dollar Notional	1,245,000,000	1,659,000,000
Foreign Exchange Contracts [Member] | Derivatives Designated as Hedging Instruments [Member] | Other Noncurrent Liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	'	'
Fair Value of Derivative, Liability	3,000,000	0
U.S. Dollar Notional	475,000,000	0
Foreign Exchange Contracts [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Deferred income taxes and other current assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	74,000,000	69,000,000
Fair Value of Derivative, Liability	'	'
U.S. Dollar Notional	7,161,000,000	5,705,000,000
Foreign Exchange Contracts [Member] | Derivatives Not Designated as Hedging Instruments [Member] | Accrued and other current liabilities [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Fair Value of Derivative, Asset	'	'
Fair Value of Derivative, Liability	71,000,000	140,000,000
U.S. Dollar Notional	$6,441,000,000	$7,892,000,000

Financial_Instruments_Informat

Financial Instruments - Information on Derivative Positions Subject to Master Netting Arrangements as if they were Presented on a Net Basis (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'	'
Gross amounts recognized in the consolidated balance sheet, Asset	$877	$1,090
Derivative Liability, Fair Value, Gross Asset	-102	-147
Cash collateral (received) posted, Asset	-478	-652
Gross amount subject to offset in master netting arrangements not offset in the consolidated balance sheet, Asset	297	291
Gross amounts recognized in the consolidated balance sheet, Liability	106	184
Derivative Asset, Fair Value, Gross Liability	-102	-147
Cash collateral (received) posted, Liability	'	'
Gross amount subject to offset in master netting arrangements not offset in the consolidated balance sheet, Liability	$4	$37

Financial_Instruments_Location

Financial Instruments - Location and Pretax Gain or Loss Amounts for Derivatives (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Derivatives not designated in a hedging relationship [Member] | Foreign Exchange Contracts [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Amount of (gain) loss recognized in Other (income) expense, net on derivatives	($82)	[1]	$24	[1]
Amount of gain recognized in Sales	-1		-10
Derivatives designated in a fair value hedging relationships [Member] | Interest Rate Swap [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Amount of (gain) loss recognized in Other (income) expense, net on derivatives	-4		0
Amount of (gain) loss recognized in Other (income) expense, net on hedged items	4		0
Derivatives designated in foreign currency cash flow hedging relationships [Member] | Foreign Exchange Contracts [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Amount of loss reclassified from AOCI to Sales	2		32
Amount of loss (gain) recognized in OCI on derivatives	102		-349
Derivatives designated in foreign currency net investment hedging relationships [Member] | Foreign Exchange Contracts [Member]	'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'
Amount of gain recognized in Other (income) expense, net on derivatives	-2	[2]	-2	[2]
Amount of loss (gain) recognized in OCI on derivatives	$42		($180)
[1]	These derivative contracts mitigate changes in the value of remeasured foreign currency denominated monetary assets and liabilities attributable to changes in foreign currency exchange rates.
[2]	There was no ineffectiveness on the hedge. Represents the amount excluded from hedge effectiveness testing.

Financial_Instruments_Informat1

Financial Instruments - Information on Available-for-sale Investments (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Fair Value	$16,392	$11,868
Amortized Cost	16,320	11,787
Gross Unrealized Gains	122	110
Gross Unrealized Losses	-50	-29
Commercial paper [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Fair Value	3,622	1,206
Amortized Cost	3,622	1,206
Gross Unrealized Gains	'	'
Gross Unrealized Losses	'	'
Corporate notes and bonds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Fair Value	7,883	7,054
Amortized Cost	7,854	7,037
Gross Unrealized Gains	38	32
Gross Unrealized Losses	-9	-15
U.S. government and agency securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Fair Value	1,882	1,236
Amortized Cost	1,885	1,239
Gross Unrealized Gains	1	1
Gross Unrealized Losses	-4	-4
Asset-backed securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Fair Value	1,230	1,300
Amortized Cost	1,232	1,303
Gross Unrealized Gains	2	1
Gross Unrealized Losses	-4	-4
Foreign government bonds [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Fair Value	641	125
Amortized Cost	641	126
Gross Unrealized Gains	1	0
Gross Unrealized Losses	-1	-1
Mortgage-backed securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Fair Value	497	476
Amortized Cost	499	479
Gross Unrealized Gains	2	2
Gross Unrealized Losses	-4	-5
Equity securities [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Fair Value	637	471
Amortized Cost	587	397
Gross Unrealized Gains	78	74
Gross Unrealized Losses	($28)	'

Financial_Instruments_Financia

Financial Instruments - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Assets	'		'
Fair Value	$16,392		$11,868
Derivative assets	877		1,090
Liabilities	'		'
Derivative liabilities	106		184
Commercial paper [Member]	'		'
Assets	'		'
Fair Value	3,622		1,206
Corporate notes and bonds [Member]	'		'
Assets	'		'
Fair Value	7,883		7,054
U.S. government and agency securities [Member]	'		'
Assets	'		'
Fair Value	1,882		1,236
Asset-backed securities [Member]	'		'
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis [Line Items]	'		'
Investments, Primary Weighted Average Life of Collateral	'5 years		'
Assets	'		'
Fair Value	1,230		1,300
Mortgage-backed securities [Member]	'		'
Assets	'		'
Fair Value	497		476
Foreign government bonds [Member]	'		'
Assets	'		'
Fair Value	641		125
Equity securities [Member]	'		'
Assets	'		'
Fair Value	637		471
Fair Value, Measurements, Recurring [Member]	'		'
Assets	'		'
Investments	16,141		11,635
Securities held for employee compensation	251		233
Purchased currency options	734	[1]	868	[1]
Derivative assets	877	[2]	1,090	[2]
Total assets	17,269		12,958
Liabilities	'		'
Total liabilities	106		184
Fair Value, Measurements, Recurring [Member] | Foreign Exchange Contracts [Member]	'		'
Assets	'		'
Derivative assets	129	[1]	209	[1]
Liabilities	'		'
Derivative liabilities	58	[1]	134	[1]
Fair Value, Measurements, Recurring [Member] | Interest Rate Swap [Member]	'		'
Assets	'		'
Derivative assets	14	[1]	13	[1]
Liabilities	'		'
Derivative liabilities	22	[1]	25	[1]
Fair Value, Measurements, Recurring [Member] | Written currency options [Member]	'		'
Liabilities	'		'
Derivative liabilities	26	[1]	25	[1]
Fair Value, Measurements, Recurring [Member] | Commercial paper [Member]	'		'
Assets	'		'
Fair Value	3,622		1,206
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]	'		'
Assets	'		'
Investments	386		238
Securities held for employee compensation	195		186
Purchased currency options	'	[1]	'	[1]
Derivative assets	0	[2]	0	[2]
Total assets	581		424
Liabilities	'		'
Total liabilities	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Foreign Exchange Contracts [Member]	'		'
Assets	'		'
Derivative assets	'	[1]	'	[1]
Liabilities	'		'
Derivative liabilities	'	[1]	'	[1]
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Interest Rate Swap [Member]	'		'
Assets	'		'
Derivative assets	'	[1]	'	[1]
Liabilities	'		'
Derivative liabilities	'	[1]	'	[1]
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Written currency options [Member]	'		'
Liabilities	'		'
Derivative liabilities	'	[1]	'	[1]
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] | Commercial paper [Member]	'		'
Assets	'		'
Fair Value	'		'
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]	'		'
Assets	'		'
Investments	15,755		11,397
Securities held for employee compensation	56		47
Purchased currency options	734	[1]	868	[1]
Derivative assets	877	[2]	1,090	[2]
Total assets	16,688		12,534
Liabilities	'		'
Total liabilities	106		184
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Exchange Contracts [Member]	'		'
Assets	'		'
Derivative assets	129	[1]	209	[1]
Liabilities	'		'
Derivative liabilities	58	[1]	134	[1]
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swap [Member]	'		'
Assets	'		'
Derivative assets	14	[1]	13	[1]
Liabilities	'		'
Derivative liabilities	22	[1]	25	[1]
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Written currency options [Member]	'		'
Liabilities	'		'
Derivative liabilities	26	[1]	25	[1]
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commercial paper [Member]	'		'
Assets	'		'
Fair Value	3,622		1,206
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]	'		'
Assets	'		'
Investments	0		0
Securities held for employee compensation	'		'
Purchased currency options	'	[1]	'	[1]
Derivative assets	0	[2]	0	[2]
Total assets	0		0
Liabilities	'		'
Total liabilities	0		0
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Foreign Exchange Contracts [Member]	'		'
Assets	'		'
Derivative assets	'	[1]	'	[1]
Liabilities	'		'
Derivative liabilities	'	[1]	'	[1]
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Swap [Member]	'		'
Assets	'		'
Derivative assets	'	[1]	'	[1]
Liabilities	'		'
Derivative liabilities	'	[1]	'	[1]
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Written currency options [Member]	'		'
Liabilities	'		'
Derivative liabilities	'	[1]	'	[1]
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commercial paper [Member]	'		'
Assets	'		'
Fair Value	'		'
Fair Value, Measurements, Recurring [Member] | Corporate notes and bonds [Member]	'		'
Assets	'		'
Fair Value	7,883		7,054
Fair Value, Measurements, Recurring [Member] | Corporate notes and bonds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]	'		'
Assets	'		'
Fair Value	'		'
Fair Value, Measurements, Recurring [Member] | Corporate notes and bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]	'		'
Assets	'		'
Fair Value	7,883		7,054
Fair Value, Measurements, Recurring [Member] | Corporate notes and bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]	'		'
Assets	'		'
Fair Value	'		'
Fair Value, Measurements, Recurring [Member] | U.S. government and agency securities [Member]	'		'
Assets	'		'
Fair Value	1,882		1,236
Fair Value, Measurements, Recurring [Member] | U.S. government and agency securities [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]	'		'
Assets	'		'
Fair Value	'		'
Fair Value, Measurements, Recurring [Member] | U.S. government and agency securities [Member] | Significant Other Observable Inputs (Level 2) [Member]	'		'
Assets	'		'
Fair Value	1,882		1,236
Fair Value, Measurements, Recurring [Member] | U.S. government and agency securities [Member] | Significant Unobservable Inputs (Level 3) [Member]	'		'
Assets	'		'
Fair Value	'		'
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member]	'		'
Assets	'		'
Fair Value	1,230	[2]	1,300	[2]
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]	'		'
Assets	'		'
Fair Value	'	[2]	'	[2]
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member] | Significant Other Observable Inputs (Level 2) [Member]	'		'
Assets	'		'
Fair Value	1,230	[2]	1,300	[2]
Fair Value, Measurements, Recurring [Member] | Asset-backed securities [Member] | Significant Unobservable Inputs (Level 3) [Member]	'		'
Assets	'		'
Fair Value	'	[2]	'	[2]
Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities [Member]	'		'
Assets	'		'
Fair Value	497	[2]	476	[2]
Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]	'		'
Assets	'		'
Fair Value	'	[2]	'	[2]
Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities [Member] | Significant Other Observable Inputs (Level 2) [Member]	'		'
Assets	'		'
Fair Value	497	[2]	476	[2]
Fair Value, Measurements, Recurring [Member] | Mortgage-backed securities [Member] | Significant Unobservable Inputs (Level 3) [Member]	'		'
Assets	'		'
Fair Value	'	[2]	'	[2]
Fair Value, Measurements, Recurring [Member] | Foreign government bonds [Member]	'		'
Assets	'		'
Fair Value	641		125
Fair Value, Measurements, Recurring [Member] | Foreign government bonds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]	'		'
Assets	'		'
Fair Value	'		'
Fair Value, Measurements, Recurring [Member] | Foreign government bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]	'		'
Assets	'		'
Fair Value	641		125
Fair Value, Measurements, Recurring [Member] | Foreign government bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]	'		'
Assets	'		'
Fair Value	'		'
Fair Value, Measurements, Recurring [Member] | Equity securities [Member]	'		'
Assets	'		'
Fair Value	386		238
Fair Value, Measurements, Recurring [Member] | Equity securities [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]	'		'
Assets	'		'
Fair Value	386		238
Fair Value, Measurements, Recurring [Member] | Equity securities [Member] | Significant Other Observable Inputs (Level 2) [Member]	'		'
Assets	'		'
Fair Value	'		'
Fair Value, Measurements, Recurring [Member] | Equity securities [Member] | Significant Unobservable Inputs (Level 3) [Member]	'		'
Assets	'		'
Fair Value	'		'
[1]	The fair value determination of derivatives includes the impact of the credit risk of counterparties to the derivatives and the Company’s own credit risk, the effects of which were not significant.
[2]	Primarily all of the asset-backed securities are highly-rated (Standard & Poor’s rating of AAA and Moody’s Investors Service rating of Aaa), secured primarily by credit card, auto loan, and home equity receivables, with weighted-average lives of primarily 5 years or less. Mortgage-backed securities represent AAA-rated securities issued or unconditionally guaranteed as to payment of principal and interest by U.S. government agencies.

Inventories_Inventories_Detail

Inventories - Inventories (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Finished goods	$1,642	$1,738
Raw materials and work in process	5,889	5,894
Supplies	222	225
Total (approximates current cost)	7,753	7,857
Increase to LIFO costs	116	73
Total current and noncurrent inventories	7,869	7,930
Recognized as:	'	'
Inventories	6,376	6,226
Other assets	$1,493	$1,704

Inventories_Textual_Detail

Inventories - Textual (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Inventory Disclosure [Abstract]	'	'
Inventories not expected to be sold within one year included in Other assets	$1,300,000,000	$1,500,000,000
Inventories produced in preparation for product launches included in Other assets	$208,000,000	$177,000,000

Other_Intangibles_Textual_Deta

Other Intangibles - Textual (Detail) (In-process research and development [Member], USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2013
In-process research and development [Member]	'
Goodwill And Other Intangible Assets [Line Items]	'
Intangible asset impairment charges related to IPR&D	$30

Joint_Ventures_and_Other_Equit2

Joint Ventures and Other Equity Method Affiliates - Equity Income from Affiliates (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Equity Income from Affiliates [Line Items]	'		'
Equity income from affiliates	$124		$133
Other [Member]	'		'
Equity Income from Affiliates [Line Items]	'		'
Equity income from affiliates	26	[1]	8	[1]
AstraZeneca LP [Member]	'		'
Equity Income from Affiliates [Line Items]	'		'
Equity income from affiliates	$98		$125
[1]	Includes results from Sanofi Pasteur MSD.

Joint_Ventures_and_Other_Equit3

Joint Ventures and Other Equity Method Affiliates - Textual (Detail) (AstraZeneca LP [Member], USD $)	3 Months Ended	12 Months Ended	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 1998	Jun. 30, 2014
			Scenario, Forecast [Member]
Equity Income from Affiliates [Line Items]	'	'	'
Limited partner interest in AZLP	1.00%	1.00%	'
General partner interest in AZLP	'	99.00%	'
Agreed-upon payment to be made by AstraZeneca at closing for exercise of option	$327	'	'
Multiple of average annual profit allocation to be included in option exercise price	10	'	'
Years prior to option exercise to be included in average annual profit allocation portion of exercise price	'3 years	'	'
Pretax gain expected to be recorded at closing upon exercise of option	'	'	$700

Joint_Ventures_and_Other_Equit4

Joint Ventures and Other Equity Method Affiliates - Summarized Financial Information for AZLP (Detail) (AstraZeneca LP [Member], USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
AstraZeneca LP [Member]	'		'
Equity Income from Affiliates [Line Items]	'		'
Sales	$1,082		$1,158
Materials and production costs	480		552
Other expense, net	393		381
Income before taxes	$209	[1]	$225	[1]
[1]	Merck’s partnership returns from AZLP are generally contractually determined as noted above and are not based on a percentage of income from AZLP, other than with respect to Merck’s 1% limited partnership interest.

Contingencies_Vioxx_Litigation

Contingencies - Vioxx Litigation - Textual (Detail) (USD $)	Mar. 31, 2014	Nov. 30, 2013	Mar. 31, 2014	Dec. 31, 2012	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
	Vioxx MDL Litigation [Member]	Vioxx MDL Litigation [Member]	Vioxx Non-Missouri [Member]	Vioxx Missouri [Member]	Vioxx Cases Brought by State Attorneys General [Member]	Vioxx Securities Lawsuits [Member]	Vioxx Canadian Litigation [Member]	Vioxx Canadian Litigation [Member]
	LegalMatter	Kentucky Attorney General [Member]			LegalMatter		Minimum [Member]	Maximum [Member]
Loss Contingencies [Line Items]	'	'	'	'	'	'	'	'
Loss contingency, pending claims number	90	'	'	'	4	'	'	'
Settlement agreement amount	'	$25,000,000	$23,000,000	'	'	'	'	'
Reflects the estimated amount of loss from the specified contingency as of the balance sheet date	'	'	'	39,000,000	'	'	21,000,000	36,000,000
Upper limits of Directors and Officers insurance coverage	'	'	'	'	'	$165,000,000	'	'

Contingencies_Fosamax_Product_

Contingencies - Fosamax Product Liability Litigation - Textual (Detail) (Fosamax [Member], USD $)	3 Months Ended			1 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
	plaintiff	Cases Alleging ONJ [Member]	Fosamax Femur Fracture [Member]	ONJ Litigation [Member]	Federal [Member]	Federal [Member]	New Jersey State Court [Member]	New Jersey State Court [Member]	California State Court [Member]	Other State Court [Member]
	LegalMatter	LegalMatter	LegalMatter		ONJ MDL [Member]	Femur Fracture MDL [Member]	Cases Alleging ONJ [Member]	Femur Fracture [Member]	Femur Fracture [Member]	Fosamax Femur Fracture [Member]
					LegalMatter	LegalMatter	LegalMatter	LegalMatter	LegalMatter	LegalMatter
Loss Contingencies [Line Items]	'	'	'	'	'	'	'	'	'	'
Loss contingency, pending claims number	5,580	1,150	4,430	'	860	1,120	285	2,785	525	6
Percentage of participation in litigation settlement condition	'	'	'	100.00%	'	'	'	'	'	'
Loss contingency, claims settled, number	'	'	'	'	4	'	'	'	'	'
Settlement agreement amount	'	'	'	$27,700,000	$3,500,000	'	'	'	'	'
Number of plaintiff groups	5,850	'	'	'	'	'	'	'	'	'
Loss contingency, claims dismissed number	'	'	'	'	'	650	'	'	'	'
Initial number of cases selected for review	'	'	'	'	'	33	'	30	10	'
Subsequent number of cases selected for review	'	'	'	'	'	'	'	50	'	'

Contingencies_JanuviaJanumet_L

Contingencies - Januvia/Janumet Litigation - Textual (Detail) (Januvia [Member])	Mar. 31, 2014
	LegalMatter
Loss Contingencies [Line Items]	'
Loss contingency, pending claims number	295
Cases Company Agreed To Toll Statute Of Limitations [Member]	'
Loss Contingencies [Line Items]	'
Loss contingency, pending claims number	11

Contingencies_NuvaRing_Litigat

Contingencies - NuvaRing Litigation - Textual (Detail) (NuvaRing [Member], USD $)	1 Months Ended	3 Months Ended
	Dec. 31, 2013	Mar. 31, 2014
		LegalMatter
Loss Contingencies [Line Items]	'	'
Loss contingency, pending claims number	'	1,935
Percentage of participation in litigation settlement condition	95.00%	'
Loss contingency, unfiled claims, number	'	1,405
Settlement agreement amount	'	$100,000,000
New Jersey State Court [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss contingency, pending claims number	'	210
Other State Court [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss contingency, pending claims number	'	7
NuvaRing MDL [Member] | Federal [Member]	'	'
Loss Contingencies [Line Items]	'	'
Loss contingency, pending claims number	'	1,715

Contingencies_PropeciaProscar_

Contingencies - Propecia/Proscar Litigation - Textual (Detail)	3 Months Ended
	Mar. 31, 2014
	plaintiff
	LegalMatter
Propecia [Member]	'
Loss Contingencies [Line Items]	'
Loss contingency, pending claims number	1,190
Number of plaintiff groups	1,450
Propecia - Prostate Cancer [Member]	'
Loss Contingencies [Line Items]	'
Number of plaintiff groups	35

Contingencies_VytorinZetia_Lit

Contingencies - Vytorin/Zetia Litigation - Textual (Detail)	Mar. 31, 2014
	Complaint
Enhanced Litigation	'
Loss Contingencies [Line Items]	'
Loss contingency, pending claims number	2
Enhanced Litigation Defendant	'
Loss Contingencies [Line Items]	'
Loss contingency, pending claims number	2
Enhanced Litigation	'
Loss Contingencies [Line Items]	'
Loss contingency, pending claims number	4

Contingencies_Legal_Defense_Re

Contingencies - Legal Defense Reserves - Textual (Detail) (Legal Defense Costs [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Legal Defense Costs [Member]	'	'
Loss Contingencies [Line Items]	'	'
Legal defense costs reserve	$190	$160

Equity_Shareholders_Equity_Det

Equity - Shareholders' Equity (Detail) (USD $)

3 Months Ended

3 Months Ended

In Millions, except Share data, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Common Stock [Member]

Common Stock [Member]

Common Stock [Member]

Common Stock [Member]

Other Paid-In Capital [Member]

Other Paid-In Capital [Member]

Retained Earnings [Member]

Retained Earnings [Member]

Accumulated Other Comprehensive Loss [Member]

Accumulated Other Comprehensive Loss [Member]

Treasury Stock [Member]

Treasury Stock [Member]

Noncontrolling Interest [Member]

Noncontrolling Interest [Member]

Increase (Decrease) in Stockholders' Equity [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Shares, Beginning Balance

3,577,103,522

'

3,577,000,000

3,577,000,000

3,577,000,000

3,577,000,000

'

'

'

'

'

'

650,000,000

550,000,000

'

'

Equity, Beginning Balance

$52,326

$55,463

$1,788

$1,788

$1,788

$1,788

$40,508

$40,646

$39,257

$39,985

($2,197)

($4,682)

($29,591)

($24,717)

$2,561

$2,443

Net Income Attributable to Merck & Co., Inc.

1,705

1,593

'

'

'

'

'

'

1,705

1,593

'

'

'

'

'

'

Cash dividends declared on common stock

-1,301

-1,306

'

'

'

'

'

'

-1,301

-1,306

'

'

'

'

'

'

Treasury stock shares purchased, Shares

'

'

'

'

'

'

'

'

'

'

'

'

21,000,000

14,000,000

'

'

Treasury stock shares purchased

-1,167

-580

'

'

'

'

'

'

'

'

'

'

-1,167

-580

'

'

Share-based compensation plans and other, Shares

'

'

'

'

'

'

'

'

'

'

'

'

-23,000,000

-4,000,000

'

'

Share-based compensation plans and other

958

133

'

'

'

'

-58

-35

'

'

'

'

1,013

168

3

'

Other comprehensive income (loss)

18

53

'

'

'

'

'

'

'

'

18

53

'

'

'

'

Supera joint venture

'

228

'

'

'

'

'

116

'

'

'

'

'

'

'

112

Net income attributable to noncontrolling interests

26

23

'

'

'

'

'

'

'

'

'

'

'

'

26

23

Distributions attributable to noncontrolling interests

-1

-1

'

'

'

'

'

'

'

'

'

'

'

'

-1

-1

Shares, Ending balance

3,577,103,522

'

3,577,000,000

3,577,000,000

3,577,000,000

3,577,000,000

'

'

'

'

'

'

648,000,000

560,000,000

'

'

Equity, Ending Balance

$52,564

$55,606

$1,788

$1,788

$1,788

$1,788

$40,450

$40,727

$39,661

$40,272

($2,179)

($4,629)

($29,745)

($25,129)

$2,589

$2,577

Equity_Textual_Detail

Equity - Textual (Detail) (USD $)	12 Months Ended
In Billions, unless otherwise specified	Dec. 31, 1998
Par value preferred stock obligation assumed in connection with the 1998 restructuring of Astra Merck Inc	$2.40
Preferred stock assumed with Astra Merck Inc. dividend per annum	5.00%

ShareBased_Compensation_Plans_1

Share-Based Compensation Plans - Amounts of Share-Based Compensation Cost Recorded in Consolidated Statement of Income (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'	'
Pretax share-based compensation expense	$56	$67
Income tax benefit	-17	-20
Total share-based compensation expense, net of taxes	$39	$47

ShareBased_Compensation_Plans_2

Share-Based Compensation Plans - Textual (Detail) (USD $)	3 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'	'
Number of RSUs granted during the period	49	32
Weighted-average grant date fair value of RSUs issued during the period	$54.89	$41.09
Options granted by company	80	'
Weighted- average exercise price of options granted in period	$54.89	'
Weighted- average fair value per option granted	$8.10	'
Total pretax unrecognized compensation expense related to nonvested stock options, RSU and PSU awards	$657	'
Weighted average period in years of recognition for nonvested stock options, RSU and PSU awards	'2 years 3 months	'

ShareBased_Compensation_Plans_3

Share-Based Compensation Plans - Assumptions Used to Determine Weighted-Average Fair Value of Options Granted (Detail)	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Expected dividend yield	4.20%
Risk-free interest rate	2.10%
Expected volatility	24.20%
Expected life (years)	'7 years

Pension_and_Other_Postretireme2

Pension and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Pension Plans, Defined Benefit [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Service cost	$151	$175
Interest cost	175	166
Expected return on plan assets	-300	-275
Net amortization	27	84
Termination benefits	14	2
Curtailments	-9	0
Net periodic benefit cost	58	152
Other Postretirement Benefit Plans, Defined Benefit [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Service cost	19	24
Interest cost	28	27
Expected return on plan assets	-34	-31
Net amortization	-18	-12
Termination benefits	4	0
Curtailments	-20	0
Net periodic benefit cost	($21)	$8

Other_Income_Expense_Net_Other

Other (Income) Expense, Net - Other (Income) Expense, Net (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Other Income and Expenses [Abstract]	'	'
Interest income	($61)	($57)
Interest expense	188	184
Exchange losses	34	212
Other, net	-200	-57
Other (income) expense, net	($39)	$282

Other_Income_Expense_Net_Textu

Other (Income) Expense, Net - Textual (Detail)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2013	Feb. 28, 2013	Feb. 28, 2013
	USD ($)	USD ($)	Venezuela [Member]	Before devaluation [Member]	After devaluation [Member]
			USD ($)	Venezuela [Member]	Venezuela [Member]
				VEF	VEF
Component of Other Income / Expense of Nonoperating [Line Items]	'	'	'	'	'
Foreign currency exchange rate	'	'	'	4.3	6.3
Exchange losses	$34	$212	$140	'	'
Gain on disposition of technology assets	182	'	'	'	'
Interest paid	$168	$187	'	'	'

Taxes_on_Income_Textual_Detail

Taxes on Income - Textual (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Operating Loss Carryforwards [Line Items]	'	'
Effective income tax rate	17.20%	-4.30%
Tax benefit recorded from sale of technology	$300	'
Internal Revenue Service (IRS) [Member]	'	'
Operating Loss Carryforwards [Line Items]	'	'
Decrease in unrecognized tax benefits resulting from prior period tax positions	'	160

Earnings_Per_Share_Textual_Det

Earnings Per Share - Textual (Detail)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]	'	'
Common shares issuable under share-based compensation plans excluded from diluted earnings per common share because the effect would have been antidilutive	1	86

Earnings_Per_Share_Calculation

Earnings Per Share - Calculations of Earnings Per Share (Detail) (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Earnings Per Share [Abstract]	'		'
Net Income Attributable to Merck & Co., Inc.	$1,705		$1,593
Average common shares outstanding	2,934		3,022
Common shares issuable	37	[1]	31	[1]
Average common shares outstanding assuming dilution	2,971		3,053
Basic earnings per common share attributable to Merck & Co., Inc. common shareholders	$0.58		$0.53
Earnings per common share assuming dilution attributable to Merck & Co., Inc. common shareholders	$0.57		$0.52
[1]	Issuable primarily under share-based compensation plans.

Other_Comprehensive_Loss_Incom

Other Comprehensive (Loss) Income - Changes in AOCI by Component (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'		'
Accumulated Other Comprehensive Income (Loss), beginning balance	($2,197)		($4,682)
Other comprehensive income (loss) before reclassification adjustments, pretax	-45		265
Tax	61		-260
Other comprehensive income (loss) before reclassification adjustments, net of taxes	16		5
Reclassification adjustments, pretax	4		76
Tax	-2		-28
Reclassification adjustments, net of taxes	2		48
Other comprehensive income (loss), net of taxes	18		53
Accumulated Other Comprehensive Income (Loss), ending balance	-2,179		-4,629
Derivatives [Member]	'		'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'		'
Accumulated Other Comprehensive Income (Loss), beginning balance	132		-97
Other comprehensive income (loss) before reclassification adjustments, pretax	-102		349
Tax	36		-133
Other comprehensive income (loss) before reclassification adjustments, net of taxes	-66		216
Reclassification adjustments, pretax	0		32
Tax	0		-12
Reclassification adjustments, net of taxes	0	[1]	20	[1]
Other comprehensive income (loss), net of taxes	-66		236
Accumulated Other Comprehensive Income (Loss), ending balance	66		139
Investments [Member]	'		'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'		'
Accumulated Other Comprehensive Income (Loss), beginning balance	54		73
Other comprehensive income (loss) before reclassification adjustments, pretax	-5		36
Tax	7		-12
Other comprehensive income (loss) before reclassification adjustments, net of taxes	2		24
Reclassification adjustments, pretax	-5		-28
Tax	1		5
Reclassification adjustments, net of taxes	-4	[2]	-23	[2]
Other comprehensive income (loss), net of taxes	-2		1
Accumulated Other Comprehensive Income (Loss), ending balance	52		74
Employee Benefit Plans [Member]	'		'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'		'
Accumulated Other Comprehensive Income (Loss), beginning balance	-909		-3,667
Other comprehensive income (loss) before reclassification adjustments, pretax	-14		133
Tax	7		-23
Other comprehensive income (loss) before reclassification adjustments, net of taxes	-7		110
Reclassification adjustments, pretax	9		72
Tax	-3		-21
Reclassification adjustments, net of taxes	6	[3]	51	[3]
Other comprehensive income (loss), net of taxes	-1		161
Accumulated Other Comprehensive Income (Loss), ending balance	-910		-3,506
Cumulative Translation Adjustment [Member]	'		'
Accumulated Other Comprehensive Income (Loss) [Roll Forward]	'		'
Accumulated Other Comprehensive Income (Loss), beginning balance	-1,474		-991
Other comprehensive income (loss) before reclassification adjustments, pretax	76		-253
Tax	11		-92
Other comprehensive income (loss) before reclassification adjustments, net of taxes	87		-345
Reclassification adjustments, pretax	0		0
Tax	0		0
Reclassification adjustments, net of taxes	0		0
Other comprehensive income (loss), net of taxes	87		-345
Accumulated Other Comprehensive Income (Loss), ending balance	($1,387)		($1,336)
[1]	Relates to foreign currency cash flow hedges that were reclassified from AOCI to Sales.
[2]	Represents net realized gains on the sales of available-for-sale investments that were reclassified from AOCI to Other (income) expense, net.
[3]	Includes net amortization of prior service cost and actuarial gains and losses included in net periodic benefit cost (see Note 11).

Segment_Reporting_Textual_Deta

Segment Reporting - Textual (Detail)	3 Months Ended
	Mar. 31, 2014
	segment
Segment Reporting [Abstract]	'
Number of operating segments	4

Segment_Reporting_Sales_of_Com

Segment Reporting - Sales of Company's Products (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Segment Reporting Information [Line Items]	'		'
Sales	$10,264		$10,671
Other pharmaceutical [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	1,175	[1]	1,361	[1]
Pharmaceutical segment [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	8,451		8,891
Other segments [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	1,540	[2]	1,712	[2]
Operating segments [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	9,991		10,603
Other [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	273	[3]	68	[3]
Zetia [Member] | Primary Care and Women's Health [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	611		629
Vytorin [Member] | Primary Care and Women's Health [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	361		394
Januvia [Member] | Primary Care and Women's Health [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	858		884
Janumet [Member] | Primary Care and Women's Health [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	476		409
NuvaRing [Member] | Primary Care and Women's Health [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	168		151
Follistim AQ [Member] | Primary Care and Women's Health [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	110		122
Dulera [Member] | Primary Care and Women's Health [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	102		68
Implanon [Member] | Primary Care and Women's Health [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	102		84
PegIntron [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	112		126
Victrelis [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	59		110
Isentress [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	390		362
Cancidas [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	166		162
Invanz [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	114		110
Noxafil [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	74		65
Bridion [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	73		63
Primaxin [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	71		84
Remicade [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	604		549
Simponi [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	157		108
Cosopt/Trusopt [Member] | Hospital and Specialty [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	99		105
Emend [Member] | Oncology [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	122		116
Temodar [Member] | Oncology [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	83		216
Nasonex [Member] | Diversified Brands [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	312		385
Singulair [Member] | Diversified Brands [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	271		337
Clarinex [Member] | Diversified Brands [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	62		61
Cozaar/Hyzaar [Member] | Diversified Brands [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	205		267
Arcoxia [Member] | Diversified Brands [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	128		121
Fosamax [Member] | Diversified Brands [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	123		137
Propecia [Member] | Diversified Brands [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	74		68
Zocor [Member] | Diversified Brands [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	64		82
Remeron [Member] | Diversified Brands [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	50		52
Gardasil [Member] | Vaccines [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	383	[4]	390	[4]
ProQuad/M-M-R II/Varivax [Member] | Vaccines [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	280	[4]	272	[4]
RotaTeq [Member] | Vaccines [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	169	[4]	162	[4]
Zostavax [Member] | Vaccines [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	142	[4]	168	[4]
Pneumovax 23 [Member] | Vaccines [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Sales	101	[4]	111	[4]
Saphris/Sycrest [Member]	'		'
Segment Reporting Information [Line Items]	'		'
Proceeds from sale of intangible assets	$232		'
[1]	Other pharmaceutical primarily reflects sales of other human health pharmaceutical products, including products within the franchises not listed separately.
[2]	Represents the non-reportable segments of Animal Health, Consumer Care and Alliances. The Alliances segment includes revenue from the Company’s relationship with AZLP.
[3]	Other revenues are primarily comprised of miscellaneous corporate revenues, third-party manufacturing sales, sales related to divested products or businesses and other supply sales not included in segment results. In January 2014, Merck received $232 million in connection with the sale of the U.S. marketing rights to Saphris (see Note 3). In October 2013, the Company divested a substantial portion of its third-party manufacturing sales (see Note 2).
[4]	These amounts do not reflect sales of vaccines sold in most major European markets through the Company’s joint venture, Sanofi Pasteur MSD, the results of which are reflected in Equity income from affiliates. These amounts do, however, reflect supply sales to Sanofi Pasteur MSD.

Segment_Reporting_Reconciliati

Segment Reporting - Reconciliation of Segment Profits to Income Before Taxes (Detail) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]	'	'
Income Before Taxes	$2,091	$1,550
Interest income	61	57
Interest expense	-188	-184
Equity income from affiliates	124	133
Depreciation and amortization	-1,754	-1,674
Research and development	-1,574	-1,907
Restructuring costs	-125	-119
Pharmaceutical segment [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Income Before Taxes	5,197	5,345
Other segments [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Income Before Taxes	700	899
Operating segments [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Income Before Taxes	5,897	6,244
Other [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Income Before Taxes	213	-14
Unallocated [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Interest income	61	57
Interest expense	-188	-184
Equity income from affiliates	55	-2
Depreciation and amortization	-620	-479
Research and development	-1,289	-1,663
Amortization of purchase accounting adjustments	-1,126	-1,184
Restructuring costs	-125	-119
Other unallocated, net	($787)	($1,106)