Merck & Co. (MRK) 10-K27 Feb 152014 FY Annual reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Jan. 31, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	MRK
Entity Registrant Name	Merck & Co., Inc.
Entity Central Index Key	310158
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		2,838,192,933
Entity Public Float			$167,695

Consolidated_Statement_of_Inco

Consolidated Statement of Income (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Sales	$42,237	$44,033	$47,267
Costs, Expenses and Other
Materials and production	16,768	16,954	16,446
Marketing and administrative	11,606	11,911	12,776
Research and development	7,180	7,503	8,168
Restructuring costs	1,013	1,709	664
Equity income from affiliates	-257	-404	-642
Other (income) expense, net	-11,356	815	1,116
Total Costs, Expenses and Other	24,954	38,488	38,528
Income Before Taxes	17,283	5,545	8,739
Taxes on Income	5,349	1,028	2,440
Net Income	11,934	4,517	6,299
Less: Net Income Attributable to Noncontrolling Interests	14	113	131
Net Income Attributable to Merck & Co., Inc.	$11,920	$4,404	$6,168
Basic Earnings per Common Share Attributable to Merck & Co., Inc. Common Shareholders (in dollars per share)	$4.12	$1.49	$2.03
Earnings per Common Share Assuming Dilution Attributable to Merck & Co., Inc. Common Shareholders (in dollars per share)	$4.07	$1.47	$2

Consolidated_Statement_of_Comp

Consolidated Statement of Comprehensive Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net Income Attributable to Merck & Co., Inc.	$11,920	$4,404	$6,168
Other Comprehensive Income (Loss) Net of Taxes:
Net unrealized gain (loss) on derivatives, net of reclassifications	398	229	-101
Net unrealized gain (loss) on investments, net of reclassifications	57	-19	52
Benefit plan net (loss) gain and prior service (cost) credit, net of amortization	-2,077	2,758	-1,321
Cumulative translation adjustment	-504	-483	-180
Other comprehensive income (loss), net of taxes	-2,126	2,485	-1,550
Comprehensive Income Attributable to Merck & Co., Inc.	$9,794	$6,889	$4,618

Consolidated_Balance_Sheet

Consolidated Balance Sheet (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Current Assets
Cash and cash equivalents	$7,441		$15,621
Short-term investments	8,278		1,865
Accounts receivable (net of allowance for doubtful accounts of $153 in 2014 and $146 in 2013) (excludes accounts receivable of $80 in 2014 and $275 in 2013 classified in Other assets - see Note 5)	6,626		7,184
Inventories (excludes inventories of $1,664 in 2014 and $1,704 in 2013 classified in Other assets - see Note 6)	5,571		6,226
Deferred income taxes and other current assets	5,257		4,789
Total current assets	33,173		35,685
Investments	13,515		9,770
Property, Plant and Equipment (at cost)
Land	541		550
Buildings	13,101		13,627
Machinery, equipment and office furnishings	16,050		17,106
Construction in progress	1,448		1,811
Property, Plant and Equipment, Gross	31,140		33,094
Less: accumulated depreciation	18,004		18,121
Property, Plant and Equipment, Net, Total	13,136		14,973
Goodwill	12,992	[1]	12,301
Other Intangibles, Net	20,386		23,801
Other Assets	5,133		9,115
Total Assets	98,335		105,645
Current Liabilities
Loans payable and current portion of long-term debt	2,704		4,521
Trade accounts payable	2,625		2,274
Accrued and other current liabilities	10,523		9,501
Income taxes payable	1,606		251
Dividends payable	1,308		1,321
Total current liabilities	18,766		17,868
Long-Term Debt	18,699		20,539
Deferred Income Taxes	4,266		6,776
Other Noncurrent Liabilities	7,813		8,136
Merck & Co., Inc. Stockholdersâ€™ 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	40,423		40,508
Retained earnings	46,021		39,257
Accumulated other comprehensive loss	-4,323		-2,197
Stockholders' equity before deduction for treasury stock	83,909		79,356
Less treasury stock, at cost: 738,963,326 shares in 2014 and 649,576,808 shares in 2013	35,262		29,591
Total Merck & Co., Inc. stockholdersâ€™ equity	48,647		49,765
Noncontrolling Interests	144		2,561
Total equity	48,791		52,326
Total Liabilities and Equity	$98,335		$105,645

[1]	Accumulated goodwill impairment losses at December 31, 2014 were $93 million.

Consolidated_Balance_Sheet_Par

Consolidated Balance Sheet (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$153	$146
Accounts receivable classified in other assets	80	275
Inventories classified in other assets	$1,664	$1,704
Common stock, par value (in dollars per share)	$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	738,963,326	649,576,808

Consolidated_Statement_of_Equi

Consolidated Statement of Equity (USD $)	Total	Common Stock [Member]	Other Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
In Millions, unless otherwise specified	Total	Common Stock [Member]	Other Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2011	$56,943	$1,788	$40,663	$38,990	($3,132)	($23,792)	$2,426
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Attributable to Merck & Co., Inc.	6,168			6,168
Other comprehensive income (loss), net of taxes	-1,550				-1,550
Cash dividends declared on common stock	-5,173			-5,173
Treasury stock shares purchased	-2,591					-2,591
Net income attributable to noncontrolling interests	131						131
Distributions attributable to noncontrolling interests	-120						-120
Share-based compensation plans and other	1,655		-17			1,666	6
Ending Balance at Dec. 31, 2012	55,463	1,788	40,646	39,985	-4,682	-24,717	2,443
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Attributable to Merck & Co., Inc.	4,404			4,404
Other comprehensive income (loss), net of taxes	2,485				2,485
Cash dividends declared on common stock	-5,132			-5,132
Supera joint venture formation	228		116				112
Treasury stock shares purchased	-6,516					-6,516
Net income attributable to noncontrolling interests	113						113
Distributions attributable to noncontrolling interests	-120						-120
Share-based compensation plans and other	1,401		-254			1,642	13
Ending Balance at Dec. 31, 2013	52,326	1,788	40,508	39,257	-2,197	-29,591	2,561
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Attributable to Merck & Co., Inc.	11,920			11,920
Other comprehensive income (loss), net of taxes	-2,126				-2,126
Cash dividends declared on common stock	-5,156			-5,156
Treasury stock shares purchased	-7,703					-7,703
AstraZeneca option exercise	-2,400						-2,400
Net income attributable to noncontrolling interests	14						14
Distributions attributable to noncontrolling interests	-77						-77
Share-based compensation plans and other	1,993		-85			2,032	46
Ending Balance at Dec. 31, 2014	$48,791	$1,788	$40,423	$46,021	($4,323)	($35,262)	$144

Consolidated_Statement_of_Equi1

Consolidated Statement of Equity (Parenthetical) (USD $)	12 Months Ended
Consolidated Statement of Equity (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Common stock, dividends declared (in dollars per share)	$1.77	$1.73	$1.69

Consolidated_Statement_of_Cash

Consolidated Statement of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash Flows from Operating Activities
Net income	$11,934	$4,517	$6,299
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	6,691	6,988	6,978
Intangible asset impairment charges	1,222	765	200
Gain on divestiture of Merck Consumer Care	-11,209	0	0
Gain on AstraZeneca option exercise	-741	0	0
Loss on extinguishment of debt	628	0	0
Equity income from affiliates	-257	-404	-642
Dividends and distributions from equity method affiliates	185	237	291
Deferred income taxes	-2,600	-330	669
Share-based compensation	278	276	335
Other	-95	399	28
Net changes in assets and liabilities:
Accounts receivable	-554	436	349
Inventories	79	-365	-482
Trade accounts payable	593	522	-302
Accrued and other current liabilities	1,635	-397	-717
Income taxes payable	-21	-1,421	-34
Noncurrent liabilities	190	-132	-1,747
Other	-98	563	-1,203
Net Cash Provided by Operating Activities	7,860	11,654	10,022
Cash Flows from Investing Activities
Capital expenditures	-1,317	-1,548	-1,954
Purchases of securities and other investments	-24,944	-17,991	-12,841
Proceeds from sales of securities and other investments	15,114	16,298	7,783
Divestiture of Consumer Care business, net of cash divested	13,951	0	0
Dispositions of other businesses, net of cash divested	1,169	46	0
Proceeds from AstraZeneca option exercise	419	0	0
Acquisition of Idenix Pharmaceuticals, Inc., net of cash acquired	-3,700	0	0
Acquisitions of other businesses, net of cash acquired	-181	-246	0
Acquisition of Bayer AG collaboration rights	-1,000	0	0
Cash inflows from net investment hedges	195	350	39
Other	-80	-57	168
Net Cash Used in Investing Activities	-374	-3,148	-6,805
Cash Flows from Financing Activities
Net change in short-term borrowings	-460	-159	624
Payments on debt	-6,617	-1,775	-22
Proceeds from issuance of debt	3,146	6,467	2,562
Purchases of treasury stock	-7,703	-6,516	-2,591
Dividends paid to stockholders	-5,170	-5,157	-5,116
Other dividends paid	-77	-120	-120
Proceeds from exercise of stock options	1,560	1,210	1,310
Other	208	60	86
Net Cash Used in Financing Activities	-15,113	-5,990	-3,267
Effect of Exchange Rate Changes on Cash and Cash Equivalents	-553	-346	-30
Net (Decrease) Increase in Cash and Cash Equivalents	-8,180	2,170	-80
Cash and Cash Equivalents at Beginning of Year	15,621	13,451	13,531
Cash and Cash Equivalents at End of Year	$7,441	$15,621	$13,451

Nature_of_Operations

Nature of Operations	12 Months Ended
Nature of Operations	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	Nature of Operations
Nature of Operations	Merck & Co., Inc. (“Merck” or “the Company”) is a global health care company that delivers innovative health solutions through its prescription medicines, vaccines, biologic therapies and animal health products, which it markets directly and through its joint ventures. The Company’s operations are principally managed on a products basis and are comprised of three operating segments, which are the Pharmaceutical, Animal Health and Alliances segments, and one reportable segment, which is the Pharmaceutical segment. 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. 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. On October 1, 2014, the Company divested its Consumer Care segment (see Note 4) that developed, manufactured and marketed over-the-counter, foot care and sun care products.

Summary_of_Accounting_Policies

Summary of Accounting Policies	12 Months Ended
Summary of Accounting Policies	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Accounting Policies	Summary of Accounting Policies
	Principles of Consolidation — The consolidated financial statements include the accounts of the Company and all of its subsidiaries in which a controlling interest is maintained. Intercompany balances and transactions are eliminated. Controlling interest is determined by majority ownership interest and the absence of substantive third-party participating rights or, in the case of variable interest entities, by majority exposure to expected losses, residual returns or both. For those consolidated subsidiaries where Merck ownership is less than 100%, the outside shareholders’ interests are shown as Noncontrolling interests in equity. Investments in affiliates over which the Company has significant influence but not a controlling interest, such as interests in entities owned equally by the Company and a third party that are under shared control, are carried on the equity basis.
	Mergers and Acquisitions — In a business combination, the acquisition method of accounting requires that the assets acquired and liabilities assumed be recorded as of the date of the merger or acquisition at their respective fair values with limited exceptions. Assets acquired and liabilities assumed in a business combination that arise from contingencies are recognized at fair value if fair value can reasonably be estimated. If the acquisition date fair value of an asset acquired or liability assumed that arises from a contingency cannot be determined, the asset or liability is recognized if probable and reasonably estimable; if these criteria are not met, no asset or liability is recognized. 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. Accordingly, the Company may be required to value assets at fair value measures that do not reflect the Company’s intended use of those assets. Any excess of the purchase price (consideration transferred) over the estimated fair values of net assets acquired is recorded as goodwill. Transaction costs and costs to restructure the acquired company are expensed as incurred. The operating results of the acquired business are reflected in the Company’s consolidated financial statements after the date of the merger or acquisition. If the Company determines the assets acquired do not meet the definition of a business under the acquisition method of accounting, the transaction will be accounted for as an acquisition of assets rather than a business combination and, therefore, no goodwill will be recorded.
	Foreign Currency Translation — The net assets of international subsidiaries where the local currencies have been determined to be the functional currencies are translated into U.S. dollars using current exchange rates. The U.S. dollar effects that arise from translating the net assets of these subsidiaries at changing rates are recorded in the foreign currency translation account, which is included in Accumulated other comprehensive income (loss) (“AOCI”) and reflected as a separate component of equity. For those subsidiaries that operate in highly inflationary economies and for those subsidiaries where the U.S. dollar has been determined to be the functional currency, non-monetary foreign currency assets and liabilities are translated using historical rates, while monetary assets and liabilities are translated at current rates, with the U.S. dollar effects of rate changes included in Other (income) expense, net.
	Cash Equivalents — Cash equivalents are comprised of certain highly liquid investments with original maturities of less than three months.
	Inventories — Inventories are valued at the lower of cost or market. The cost of a substantial majority of domestic pharmaceutical and vaccine inventories is determined using the last-in, first-out (“LIFO”) method for both financial reporting and tax purposes. The cost of all other inventories is determined using the first-in, first-out (“FIFO”) method. Inventories consist of currently marketed products, as well as certain inventories produced in preparation for product launches that are considered to have a high probability of regulatory approval. In evaluating the recoverability of inventories produced in preparation for product launches, the Company considers the likelihood that revenue will be obtained from the future sale of the related inventory together with the status of the product within the regulatory approval process.
	Investments — Investments in marketable debt and equity securities classified as available-for-sale are reported at fair value. Fair values of the Company’s investments are determined using quoted market prices in active markets for identical assets or liabilities or 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. Changes in fair value that are considered temporary are reported net of tax in Other Comprehensive Income (“OCI”). For declines in the fair value of equity securities that are considered other-than-temporary, impairment losses are charged to Other (income) expense, net. The Company considers available evidence in evaluating potential impairments of its investments, including the duration and extent to which fair value is less than cost and, for equity securities, the Company’s ability and intent to hold the investments. For debt securities, an other-than-temporary impairment has occurred if the Company does not expect to recover the entire amortized cost basis of the debt security. If the Company does not intend to sell the impaired debt security, and it is not more likely than not it will be required to sell the debt security before the recovery of its amortized cost basis, the amount of the other-than-temporary impairment recognized in earnings, recorded in Other (income) expense, net, is limited to the portion attributed to credit loss. The remaining portion of the other-than-temporary impairment related to other factors is recognized in OCI. Realized gains and losses for both debt and equity securities are included in Other (income) expense, net.
	Revenue Recognition — Revenues from sales of products are recognized when title and risk of loss passes to the customer, typically upon delivery. Recognition of revenue also requires reasonable assurance of collection of sales proceeds and completion of all performance obligations. Domestically, sales discounts are issued to customers as direct discounts at the point-of-sale, indirectly through an intermediary wholesaler, known as chargebacks, or indirectly in the form of rebates. Additionally, sales are generally made with a limited right of return under certain conditions. Revenues are recorded net of provisions for sales discounts and returns, which are established at the time of sale. In addition, revenues are recorded net of time value of money discounts if collection of accounts receivable is expected to be in excess of one year. Accruals for chargebacks are reflected as a direct reduction to accounts receivable and accruals for rebates are recorded as current liabilities. The accrued balances relative to the provisions for chargebacks and rebates included in Accounts receivable and Accrued and other current liabilities were $112 million and $2.0 billion, respectively, at December 31, 2014 and $87 million and $1.6 billion, respectively, at December 31, 2013.
	The Company recognizes revenue from the sales of vaccines to the Federal government for placement into vaccine stockpiles in accordance with Securities and Exchange Commission (“SEC”) Interpretation, Commission Guidance Regarding Accounting for Sales of Vaccines and BioTerror Countermeasures to the Federal Government for Placement into the Pediatric Vaccine Stockpile or the Strategic National Stockpile.
	Depreciation — Depreciation is provided over the estimated useful lives of the assets, principally using the straight-line method. For tax purposes, accelerated tax methods are used. The estimated useful lives primarily range from 10 to 50 years for Buildings, and from 3 to 15 years for Machinery, equipment and office furnishings. Depreciation expense was $2.5 billion in 2014, $2.2 billion in 2013 and $2.0 billion in 2012.
	Advertising and Promotion Costs — Advertising and promotion costs are expensed as incurred. The Company recorded advertising and promotion expenses of $2.3 billion, $2.5 billion and $2.8 billion in 2014, 2013 and 2012, respectively.
	Software Capitalization — The Company capitalizes certain costs incurred in connection with obtaining or developing internal-use software including external direct costs of material and services, and payroll costs for employees directly involved with the software development. Capitalized software costs are included in Property, plant and equipment and amortized beginning when the software project is substantially complete and the asset is ready for its intended use. Capitalized software costs associated with projects that are being amortized over 6 to 10 years (including the Company’s on-going multi-year implementation of an enterprise-wide resource planning system) were $505 million and $548 million, net of accumulated amortization at December 31, 2014 and 2013, respectively. All other capitalized software costs are being amortized over periods ranging from 3 to 5 years. Costs incurred during the preliminary project stage and post-implementation stage, as well as maintenance and training costs, are expensed as incurred.
	Goodwill — Goodwill represents the excess of the consideration transferred over the fair value of net assets of businesses purchased. Goodwill is assigned to reporting units and evaluated for impairment on at least an annual basis, or more frequently if impairment indicators exist, by first assessing qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the Company concludes it is more likely than not that the fair value of a reporting unit is less than its carrying amount, a quantitative fair value test is performed.
	Acquired Intangibles — Acquired intangibles include products and product rights, tradenames and patents, which are recorded at fair value, assigned an estimated useful life, and are amortized primarily on a straight-line basis over their estimated useful lives ranging from 3 to 20 years (see Note 7). The Company periodically evaluates whether current facts or circumstances indicate that the carrying values of its acquired intangibles may not be recoverable. If such circumstances are determined to exist, an estimate of the undiscounted future cash flows of these assets, or appropriate asset groupings, is compared to the carrying value to determine whether an impairment exists. If the asset is determined to be impaired, the loss is measured based on the difference between the carrying value of the intangible asset and its fair value, which is determined based on the net present value of estimated future cash flows.
	Acquired In-Process Research and Development — Acquired in-process research and development (“IPR&D”) that the Company acquires through business combinations represents the fair value assigned to incomplete research projects which, at the time of acquisition, have not reached technological feasibility. The amounts are capitalized and are accounted for as indefinite-lived intangible assets, subject to impairment testing until completion or abandonment of the projects. Upon successful completion of each project, Merck will make a determination as to the then useful life of the intangible asset, generally determined by the period in which the substantial majority of the cash flows are expected to be generated, and begin amortization. The Company tests IPR&D for impairment at least annually, or more frequently if impairment indicators exist, by first assessing qualitative factors to determine whether it is more likely than not that the fair value of the IPR&D intangible asset is less than its carrying amount. If the Company concludes it is more likely than not that the fair value is less than the carrying amount, a quantitative test that compares the fair value of the IPR&D intangible asset with its carrying value is performed. If the fair value is less than the carrying amount, an impairment loss is recognized in operating results.
	Contingent Consideration — Certain of the Company’s business acquisitions involve the potential for future payment of consideration that is contingent upon the achievement of performance milestones, including product development milestones and royalty payments on future product sales. The fair value of contingent consideration liabilities is determined at the acquisition date using unobservable inputs. These inputs include the estimated amount and timing of projected cash flows, the probability of success (achievement of the contingent event) and the risk-adjusted discount rate used to present value the probability-weighted cash flows. Subsequent to the acquisition date, at each reporting period, the contingent consideration liability is remeasured at current fair value with changes recorded in earnings. Changes in any of the inputs may result in a significantly different fair value adjustment.
	Research and Development — Research and development is expensed as incurred. Upfront and milestone payments due to third parties in connection with research and development collaborations prior to regulatory approval are expensed as incurred. Payments due to third parties upon or subsequent to regulatory approval are capitalized and amortized over the shorter of the remaining license or product patent life. Amounts due from collaborative partners related to development activities are generally reflected as a reduction of research and development expenses when the specific milestone has been achieved. Nonrefundable advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. Research and development expenses include restructuring costs and IPR&D impairment charges in all periods. In addition, research and development expenses in 2014 include a charge to increase the fair value of a liability for contingent consideration.
	Share-Based Compensation — The Company expenses all share-based payments to employees over the requisite service period based on the grant-date fair value of the awards.
	Restructuring Costs — The Company records liabilities for costs associated with exit or disposal activities in the period in which the liability is incurred. In accordance with existing benefit arrangements, employee termination costs are accrued when the restructuring actions are probable and estimable. When accruing these costs, the Company will recognize the amount within a range of costs that is the best estimate within the range. When no amount within the range is a better estimate than any other amount, the Company recognizes the minimum amount within the range. Costs for one-time termination benefits in which the employee is required to render service until termination in order to receive the benefits are recognized ratably over the future service period.
	Contingencies and Legal Defense Costs — The Company records accruals for contingencies and legal defense costs expected to be incurred in connection with a loss contingency when it is probable that a liability has been incurred and the amount can be reasonably estimated.
	Taxes on Income — Deferred taxes are recognized for the future tax effects of temporary differences between financial and income tax reporting based on enacted tax laws and rates. The Company evaluates tax positions to determine whether the benefits of tax positions are more likely than not of being sustained upon audit based on the technical merits of the tax position. For tax positions that are more likely than not of being sustained upon audit, the Company recognizes the largest amount of the benefit that is greater than 50% likely of being realized upon ultimate settlement in the financial statements. For tax positions that are not more likely than not of being sustained upon audit, the Company does not recognize any portion of the benefit in the financial statements. The Company recognizes interest and penalties associated with uncertain tax positions as a component of Taxes on income in the Consolidated Statement of Income.
	Use of Estimates — The consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States (“GAAP”) and, accordingly, include certain amounts that are based on management’s best estimates and judgments. Estimates are used when accounting for amounts recorded in connection with mergers and acquisitions, including initial fair value determinations of assets and liabilities, primarily IPR&D and other intangible assets, as well as subsequent fair value measurements. Additionally, estimates are used in determining such items as provisions for sales discounts and returns, depreciable and amortizable lives, recoverability of inventories, including those produced in preparation for product launches, amounts recorded for contingencies, environmental liabilities and other reserves, pension and other postretirement benefit plan assumptions, share-based compensation assumptions, restructuring costs, impairments of long-lived assets (including intangible assets and goodwill) and investments, and taxes on income. Because of the uncertainty inherent in such estimates, actual results may differ from these estimates.
	Reclassifications — Certain reclassifications have been made to prior year amounts to conform to the current year presentation.
	Recently Issued Accounting Standards — In May 2014, the Financial Accounting Standards Board issued amended accounting guidance on revenue recognition that will be applied to all contracts with customers. The objective of the new guidance is to improve comparability of revenue recognition practices across entities and to provide more useful information to users of financial statements through improved disclosure requirements. This guidance is effective for annual and interim periods beginning in 2017. Early adoption is not permitted. The Company is currently assessing the impact of adoption on its consolidated financial statements.

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2014
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring
	2013 Restructuring Program
	In 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 $1.2 billion in both 2014 and 2013 related to this restructuring program. Since inception of the 2013 Restructuring Program through December 31, 2014, Merck has recorded total pretax accumulated costs of approximately $2.5 billion and eliminated approximately 6,095 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 $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. In conjunction with the sale, the parties entered into a strategic long-term supply agreement whereby Aspen will supply API to the Company and approximately 960 employees who support the API business were transferred from Merck to Aspen. 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 notes receivable consist of a $261 million note with a present value of $138 million due in 2023 and a $67.5 million note with a present value of $60 million that is payable over five years beginning on December 31, 2014. Of the cash portion of the consideration, the Company received $172 million in the fourth quarter of 2013. The remaining $533 million was received by the Company in January 2014; therefore, at December 31, 2013, this amount was recorded as a receivable within Deferred income taxes and other current assets on the Consolidated Balance Sheet. In conjunction with this transaction, the Company transferred inventory of $420 million, property, plant and equipment of $220 million and cash of $125 million to Aspen, reduced goodwill by $45 million, other intangible assets by $45 million and other assets by $23 million and recorded $90 million of transaction-related liabilities. This transaction resulted in a loss of $65 million that was recorded within Restructuring costs in 2013.
	The Company recorded total pretax costs of $730 million in 2014, $1.1 billion in 2013 and $951 million in 2012 related to this restructuring program. Since inception of the Merger Restructuring Program through December 31, 2014, Merck has recorded total pretax accumulated costs of approximately $7.9 billion and eliminated approximately 28,410 positions comprised of employee separations, as well as the elimination of contractors and vacant positions. Approximately 3,440 position eliminations remain pending under this program as of December 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 primarily 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 $8.5 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 $54 million and $48 million were recorded in 2013 and 2012, respectively, related to the 2008 Restructuring Program. Effective July 1, 2013, any remaining activities under the 2008 Restructuring Program are being accounted for as part of the Merger Restructuring Program.
	For segment reporting, restructuring charges are unallocated expenses.
	The following table summarizes the charges related to restructuring program activities by type of cost:


	Year Ended December 31, 2014	Separation			Accelerated			Other				Total
		Costs			Depreciation
	2013 Restructuring Program
	Materials and production	$	—		$	204		$	23			$	227

	Marketing and administrative	—			142			3				145

	Research and development	—			273			9				282

	Restructuring costs	566			—			28				594

		566			619			63				1,248

	Merger Restructuring Program
	Materials and production	—			225			30				255

	Marketing and administrative	—			56			(1		)		55

	Research and development	—			—			1				1

	Restructuring costs	108			—			311				419

		108			281			341				730

		$	674		$	900		$	404			$	1,978

	Year Ended December 31, 2013
	2013 Restructuring Program
	Materials and production	$	—		$	186		$	7			$	193

	Marketing and administrative	—			72			3				75

	Research and development	—			76			(1		)		75

	Restructuring costs	866			—			32				898

		866			334			41				1,241

	Merger Restructuring Program

	Materials and production	—			151			98				249

	Marketing and administrative	—			63			3				66

	Research and development	—			27			(1		)		26

	Restructuring costs	481			—			284				765

	481			241			384				1,106

2008 Restructuring Program
Materials and production	—			(2		)	6				4

Marketing and administrative	—			4			—				4

Restructuring costs	34			—			12				46

	34			2			18				54

	$	1,381		$	577		$	443			$	2,401

Year Ended December 31, 2012
Merger Restructuring Program
Materials and production	$	—		$	92		$	70			$	162

Marketing and administrative	—			75			6				81

Research and development	—			53			4				57

Restructuring costs	497			—			154				651

	497			220			234				951

2008 Restructuring Program
Materials and production	—			7			19				26

Marketing and administrative	—			8			1				9

Restructuring costs	(8		)	—			21				13

	(8		)	15			41				48

	$	489		$	235		$	275			$	999

Separation costs are associated with actual headcount reductions, as well as those headcount reductions which were probable and could be reasonably estimated. Positions eliminated under the 2013 Restructuring Program were approximately 4,555 in 2014 and 1,540 in 2013. Positions eliminated under the Merger Restructuring Program were approximately 1,530 in 2014, 4,475 in 2013 and 3,975 in 2012. 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, 2013 and 2012 includes $240 million, $259 million and $155 million, respectively, of 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 13) and share-based compensation. Other activity also reflects net pretax (losses) gains resulting from sales of facilities and related assets of $(133) million in 2014, $(64) million in 2013 (primarily reflecting the loss on the transaction with Aspen discussed above) and $28 million in 2012.
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:


	Separation			Accelerated			Other				Total
	Costs			Depreciation
2013 Restructuring Program
Restructuring reserves January 1, 2013	$	—		$	—		$	—			$	—

Expenses	866			334			41				1,241

(Payments) receipts, net	(121		)	—			9				(112		)

Non-cash activity	—			(334		)	(27		)		(361		)

Restructuring reserves December 31, 2013	745			—			23				768

Expenses	566			619			63				1,248

(Payments) receipts, net	(816		)	—			(124		)		(940		)

Non-cash activity	—			(619		)	52				(567		)

Restructuring reserves December 31, 2014 (1)	$	495		$	—		$	14			$	509

Merger Restructuring Program
Restructuring reserves January 1, 2013	$	699		$	—		$	19			$	718

Expenses	481			241			384				1,106

(Payments) receipts, net	(517		)	—			(258		)		(775		)

Non-cash activity	62			(241		)	(133		)		(312		)

Restructuring reserves December 31, 2013	725			—			12				737

Expenses	108			281			341				730

(Payments) receipts, net	(297		)	—			(232		)		(529		)

Non-cash activity	—			(281		)	(115		)		(396		)

Restructuring reserves December 31, 2014 (1)	$	536		$	—		$	6			$	542


(1)	The cash outlays associated with the 2013 Restructuring Program are expected to be substantially completed by the end of 2015. The non-manufacturing cash outlays associated with the Merger Restructuring Program were substantially completed by the end of 2013; the remaining cash outlays are expected to be substantially completed by the end of 2016.

Acquisitions_Divestitures_Rese

Acquisitions, Divestitures, Research Collaborations and License Agreements	12 Months Ended
	Dec. 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 December 2014, Merck and Cubist Pharmaceuticals, Inc. (“Cubist”) announced a definitive agreement under which Merck would acquire Cubist for a total purchase price of approximately $9.5 billion. Cubist is a leader in the development of new therapies to treat serious and potentially life-threatening infections caused by a broad range of increasingly drug-resistant bacteria. This transaction closed on January 21, 2015; accordingly, the results of operations of the acquired business will be included in the Company’s results of operations beginning after that date.
	Also in December 2014, Merck acquired OncoEthix, a privately held biotechnology company specializing in oncology drug development. Total purchase consideration in the transaction of $153 million included an upfront cash payment of $110 million and future additional milestone payments of up to $265 million that are contingent upon certain clinical and regulatory milestones being achieved, which the Company determined had a fair value of $43 million at the acquisition date. 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 as of the acquisition date. The determination of fair value requires management to make significant estimates and assumptions. Merck recognized an intangible asset for IPR&D of $143 million related to MK-8628 (formerly OTX015), an investigational, novel oral BET (bromodomain) inhibitor currently in Phase 2 studies for the treatment of hematological malignancies and advanced solid tumors, as well as a liability for contingent consideration of $43 million and other net assets and liabilities of $10 million. The fair value of the identifiable intangible asset related to IPR&D was determined using an income approach, through which fair value is estimated based upon the asset’s probability adjusted future net cash flows, which reflects the stage of development of the project and the associated probability of successful completion. The net cash flows were then discounted to present value using a discount rate of 11.5%. The fair value of the contingent consideration was determined utilizing a probability weighted estimated cash flow stream adjusted for the expected timing of each payment also utilizing a discount rate of 11.5%. This transaction closed on December 18, 2014; accordingly, the results of operations of the acquired business have been included in the Company’s results of operations beginning after that date. Pro forma financial information has not been included because OncoEthix’s historical financial results are not significant when compared with the Company’s financial results.
	On October 1, 2014, the Company completed the sale of its Merck Consumer Care (“MCC”) business to Bayer AG (“Bayer”) for $14.2 billion ($14.0 billion net of cash divested), less customary closing adjustments as well as certain contingent amounts held back that will be payable upon the manufacturing site transfer in Canada and regulatory approval in Korea. Under the terms of the agreement, Bayer acquired Merck’s existing over-the-counter business, including the global trademark and prescription rights for Claritin and Afrin. The Company recognized a pretax gain from the sale of MCC of $11.2 billion in 2014.
	Also on October 1, 2014, the Company entered into 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 made an upfront payment to Bayer of $1.0 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 determined that Merck’s payment to access Bayer’s compounds constituted an acquisition of an asset. Of the $1.0 billion consideration paid by Merck, $915 million of fair value related to currently marketed product Adempas and was capitalized as an intangible asset subject to amortization over its estimated useful life of 12 years, and the remaining $85 million of fair value related to the vericiguat compound currently in clinical development and expensed within Research and development expenses. The fair values of Adempas and vericiguat were determined using an income approach, through which fair value is estimated based upon probability adjusted future net cash flows, and for vericiguat also for the stage of development of the project and the associated probability of successful completion. The net cash flows were then discounted to present value using a discount rate of 10.0% for Adempas and 10.5% for vericiguat. Future sales based milestones will be accrued when probable and reasonably estimable. The Company and Bayer each have the right to terminate the agreement for cause on a product-by-product basis for all products being developed and commercialized under the agreement (other than Adempas for which Bayer has no termination rights) in the event of the other party’s material, uncured breach related to any such product.
	In September 2014, Merck and Sun Pharmaceutical Industries Ltd. (“Sun Pharma”) entered into an exclusive worldwide licensing agreement for Merck’s investigational therapeutic antibody candidate, MK-3222, tildrakizumab, for the treatment of chronic plaque psoriasis, a skin ailment. Under terms of the agreement, Sun Pharma acquired worldwide rights to tildrakizumab for use in all human indications from Merck in exchange for an upfront payment of $80 million. Merck will continue all clinical development and regulatory activities, which will be funded by Sun Pharma. Upon product approval, Sun Pharma will be responsible for regulatory activities, including subsequent submissions, pharmacovigilance, post approval studies, manufacturing and commercialization of the approved product. Merck is also eligible to receive future payments associated with regulatory (including product approval) and sales milestones, as well as tiered royalties ranging from mid-single digit through teen percentage rates on sales. Merck recorded a loss of $47 million on the transaction included in Other (income) expense, net.
	In August 2014, Merck completed the acquisition of Idenix Pharmaceuticals, Inc. (“Idenix”) for approximately $3.9 billion in cash ($3.7 billion net of cash acquired). Idenix is a biopharmaceutical company engaged in the discovery and development of medicines for the treatment of human viral diseases, whose primary focus is on the development of next-generation oral antiviral therapeutics to treat hepatitis C virus (“HCV”) infection. 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 as of the acquisition date. The determination of fair value requires management to make significant estimates and assumptions. Merck recognized an intangible asset for IPR&D of $3.2 billion related to MK-3682 (formerly IDX21437), net deferred tax liabilities of $856 million and other net assets and liabilities of approximately $20 million. MK-3682 is a nucleotide prodrug in Phase 2 clinical development being evaluated for potential inclusion in the development of all oral, pan-genotypic fixed-dose combination regimens. The excess of the consideration transferred over the fair value of net assets acquired of $1.4 billion was recorded as goodwill that was allocated to the Pharmaceutical segment and is not deductible for tax purposes. The fair value of the identifiable intangible asset related to IPR&D was determined using an income approach, through which fair value is estimated based upon the asset’s probability adjusted future net cash flows, which reflects the stage of development of the project and the associated probability of successful completion. The net cash flows were then discounted to present value using a discount rate of 11.5%. This transaction closed on August 5, 2014; accordingly, the results of operations of the acquired business have been included in the Company’s results of operations beginning after that date. Pro forma financial information has not been included because Idenix’s historical financial results are not significant when compared with the Company’s financial results.
	In May 2014, Merck entered into an agreement to sell certain ophthalmic products to Santen Pharmaceutical Co., Ltd. (“Santen”) in Japan and markets in Europe and Asia Pacific. The ophthalmic products included in the agreement are Cosopt (dorzolamide hydrochloride-timolol maleate ophthalmic solution), Cosopt PF (dorzolamide hydrochloride-timolol maleate ophthalmic solution) 2%/0.5%, Trusopt (dorzolamide hydrochloride ophthalmic solution) sterile ophthalmic solution 2%, Trusopt PF (dorzolamide hydrochloride ophthalmic solution) preservative-free, Timoptic (timolol maleate ophthalmic solution), Timoptic PF (timolol maleate preservative free ophthalmic solution in unit dose dispenser), Timoptic XE (timolol maleate ophthalmic gel forming solution), Saflutan (tafluprost) and Taptiqom (tafluprost-timolol maleate ophthalmic solution, in development). The agreement provides that Santen make upfront payments and additional payments based on defined sales milestones. Santen will also purchase supply of ophthalmology products covered by the agreement for a two- to five-year period. Upon closing of the transaction in most markets on July 1, 2014, the Company received $515 million of upfront payments from Santen, net of certain adjustments, and an additional $50 million upon closing of the remaining markets on October 1, 2014. Merck recognized gains of $480 million on the transactions in 2014 included in Other (income) expense, net.
	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. Merck is eligible to receive future payments associated with the achievement of certain regulatory and commercial milestones, as well as royalties on future sales. 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 in the second quarter of 2014 (valued at $22 million at the time the shares were received). Merck recorded gains of $204 million in 2014 related to this transaction that are included in Other (income) expense, net. 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 2014.
	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 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 (subsequently acquired by Actavis plc) until patent expiry.
	In September 2013, Merck and AstraZeneca announced a worldwide out-licensing agreement for Merck’s oral small molecule inhibitor of WEE1 kinase (MK-1775) being evaluated in clinical studies in combination with standard-of-care therapies for the treatment of patients with certain types of ovarian cancer. Under the terms of the agreement, AstraZeneca paid Merck a $50 million upfront fee, which the Company recorded as revenue. In addition, Merck will be eligible to receive future payments tied to development and regulatory milestones, plus sales-related payments and tiered royalties. AstraZeneca will be responsible for all future clinical development, manufacturing and marketing.
	In April 2013, Merck and Pfizer Inc. (“Pfizer”) announced 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 end of 2013, Merck recorded research and development expenses of $125 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 a 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, 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; accordingly, the results of operations of the acquired business have been included in the Company’s results of operations beginning after that date. During 2014, as a result of changes in cash flow assumptions for certain compounds, the Company recorded $31 million of asset impairment charges related to IPR&D recorded in the Supera transaction. The changes in cash flow assumptions for these compounds, as well as for certain currently marketed products, also resulted in the write-off of the goodwill balance related to the joint venture with Supera, which was $93 million at existing exchange rates. The Company had previously recorded $15 million of impairment charges in the fourth quarter of 2013 related to the IPR&D recorded in the Supera transaction as a result of changes in cash flow assumptions for certain compounds.
	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. Remicade lost market exclusivity in major European markets in February 2015. All profits derived from Merck’s exclusive distribution of the two products are equally divided between Merck and J&J.

Financial_Instruments

Financial Instruments	12 Months Ended
	Dec. 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 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 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 Statement 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 $294 million in 2014 and pretax losses of $84 million in 2013 and $31 million in 2012 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 December 31, 2014, the Company was a party to 17 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 as detailed in the table below.


		2014
	Debt Instrument	Par Value of Debt				Number of Interest Rate Swaps Held			Total Swap Notional Amount
	0.70% notes due 2016	$	1,000			4			$	1,000

	1.30% notes due 2018	1,000				4			1,000

	5.00% notes due 2019	1,250				3			550

	3.875% notes due 2021	1,150				5			1,150

	2.40% notes due 2022	1,000				1			250

	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. During 2014, the Company terminated interest rate swap contracts that effectively converted the Company’s 6.00% fixed-rate notes due in 2017 to floating-rate instruments. The interest rate swap contracts were designated hedges of the fair value changes in the notes attributable to changes in the benchmark LIBOR swap rate. As a result of the swap terminations, the Company received $3 million in cash. The cash flows from these contracts are reported as operating activities in the Consolidated Statement of Cash Flows.
	In February 2015, in connection with the Company’s February debt offering (see Note 9), Merck entered into ten additional interest rate swap contracts with notional amounts of $250 million each that effectively convert the Company’s 1.85% notes due in 2020 and the Company’s 2.35% notes due in 2022 to floating-rate 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 as of December 31:


				2014												2013
				Fair Value of								U.S. Dollar				Fair Value of						U.S. Dollar
				Derivative								Notional				Derivative						Notional
		Balance Sheet Caption		Asset				Liability								Asset			Liability
	Derivatives Designated as Hedging Instruments
	Interest rate swap contracts (non-current)	Other assets		$	19			$	—			$	1,950			$	13		$	—		$	1,550

	Interest rate swap contracts (non-current)	Other noncurrent liabilities		—				15				2,000				—			25			2,000

	Foreign exchange contracts (current)	Deferred income taxes and other current assets		772				—				5,513				493			—			4,427

	Foreign exchange contracts (non-current)	Other assets		691				—				6,253				515			—			6,676

	Foreign exchange contracts (current)	Accrued and other current liabilities		—				—				—				—			19			1,659

				$	1,482			$	15			$	15,716			$	1,021		$	44		$	16,312

	Derivatives Not Designated as Hedging Instruments
	Foreign exchange contracts (current)	Deferred income taxes and other current assets		$	365			$	—			$	6,966			$	69		$	—		$	5,705

	Foreign exchange contracts (current)	Accrued and other current liabilities		—				88				3,386				—			140			7,892

				$	365			$	88			$	10,352			$	69		$	140		$	13,597

				$	1,847			$	103			$	26,068			$	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 at December 31:


	2014								2013
	Asset				Liability				Asset				Liability
Gross amounts recognized in the consolidated balance sheet	$	1,847			$	103			$	1,090			$	184

Gross amount subject to offset in master netting arrangements not offset in the consolidated balance sheet	(97		)		(97		)		(147		)		(147		)
Cash collateral (received) posted	(1,410		)		—				(652		)		—

Net amounts	$	340			$	6			$	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:



Years Ended December 31	2014				2013				2012
Derivatives designated in a fair value hedging relationship
Interest rate swap contracts
Amount of (gain) loss recognized in Other (income) expense, net on derivatives (1)	$	(17	)		$	12			$	—

Amount of loss (gain) recognized in Other (income) expense, net on hedged item (1)	14				(14		)		—

Derivatives designated in foreign currency cash flow hedging relationships
Foreign exchange contracts
Amount of (gain) loss reclassified from AOCI to Sales	(143		)		45				50

Amount of (gain) loss recognized in OCI on derivatives	(775		)		(306		)		204

Derivatives designated in foreign currency net investment hedging relationships
Foreign exchange contracts
Amount of gain recognized in Other (income) expense, net on derivatives (2)	(6		)		(10		)		(20		)
Amount of gain recognized in OCI on derivatives	(192		)		(363		)		(208		)
Derivatives not designated in a hedging relationship
Foreign exchange contracts
Amount of (gain) loss recognized in Other (income) expense, net on derivatives (3)	(516		)		183				382

Amount of loss recognized in Sales	15				8				30


(1)	There was $3 million and $2 million of ineffectiveness on the hedge during 2014 and 2013, respectively.

(2)	There was no ineffectiveness on the hedge. Represents the amount excluded from hedge effectiveness testing.

(3)	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 December 31, 2014, the Company estimates $457 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 at December 31 is as follows:



	2014																2013
	Fair				Amortized				Gross Unrealized								Fair			Amortized			Gross Unrealized
	Value				Cost				Gains				Losses				Value			Cost			Gains		Losses
Corporate notes and bonds	$	10,107			$	10,102			$	22			$	(17	)		$	7,054		$	7,037		$	32	$	(15	)

Commercial paper	6,970				6,970				—				—				1,206			1,206			—		—

U.S. government and agency securities	1,774				1,775				1				(2		)		1,236			1,239			1		(4		)

Asset-backed securities	1,460				1,462				1				(3		)		1,300			1,303			1		(4		)

Mortgage-backed securities	602				604				2				(4		)		476			479			2		(5		)

Foreign government bonds	385				385				—				—				125			126			—		(1		)

Equity securities	730				557				173				—				471			397			74		—

	$	22,028			$	21,855			$	199			$	(26	)		$	11,868		$	11,787		$	110	$	(29	)

Available-for-sale debt securities included in Short-term investments totaled $8.3 billion at December 31, 2014. Of the remaining debt securities, $12.0 billion mature within five years. At December 31, 2014 and 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 or liabilities are those whose values are determined using pricing models, discounted cash flow methodologies, or similar techniques with significant unobservable inputs, as well as assets or liabilities 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 at December 31 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)
	2014																2013
Assets
Investments
Corporate notes and bonds	$	—			$	10,107			$	—			$	10,107			$	—		$	7,054		$	—	$	7,054

Commercial paper	—				6,970				—				6,970				—			1,206			—		1,206

U.S. government and agency securities	—				1,774				—				1,774				—			1,236			—		1,236

Asset-backed securities (1)	—				1,460				—				1,460				—			1,300			—		1,300

Mortgage-backed securities (1)	—				602				—				602				—			476			—		476

Foreign government bonds	—				385				—				385				—			125			—		125

Equity securities	495				—				—				495				238			—			—		238

	495				21,298				—				21,793				238			11,397			—		11,635

Other assets
Securities held for employee compensation	181				54				—				235				186			47			—		233

Derivative assets (2)
Purchased currency options	—				1,252				—				1,252				—			868			—		868

Forward exchange contracts	—				576				—				576				—			209			—		209

Interest rate swaps	—				19				—				19				—			13			—		13

	—				1,847				—				1,847				—			1,090			—		1,090

Total assets	$	676			$	23,199			$	—			$	23,875			$	424		$	12,534		$	—	$	12,958

Liabilities
Other liabilities
Contingent consideration	$	—			$	—			$	428			$	428			$	—		$	—		$	69	$	69

Derivative liabilities (2)
Forward exchange contracts	—				46				—				46				—			134			—		134

Written currency options	—				42				—				42				—			25			—		25

Interest rate swaps	—				15				—				15				—			25			—		25

	—				103				—				103				—			184			—		184

Total liabilities	$	—			$	103			$	428			$	531			$	—		$	184		$	69	$	253


(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 2014. As of December 31, 2014, Cash and cash equivalents of $7.4 billion included $6.1 billion of cash equivalents (considered Level 2 in the fair value hierarchy).
Contingent Consideration
Summarized information about the changes in liabilities for contingent consideration is as follows:


	2014				2013
Fair value January 1	$	69			$	49

Changes in fair value (recorded in Research and development expenses)	316				8

Additions	43				12

Fair value December 31	$	428			$	69

During 2014, the fair value of a liability for contingent consideration related to an acquisition that occurred in 2010 increased by $316 million resulting from the progression of the program from preclinical to Phase 1. The increase resulted from a higher fair value of future regulatory milestone and royalty payments due to an increased probability of success of the program given its progression into Phase 1. In addition, during 2014, the Company recognized a liability of $43 million for contingent consideration related to the acquisition of OncoEthix in 2014 (see Note 4).

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 December 31, 2014, was $22.5 billion compared with a carrying value of $21.4 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 December 31, 2014 and 2013, Other assets included $80 million and $275 million, respectively, 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.
As of December 31, 2014, the Company’s accounts receivable in Greece, Italy, Spain and Portugal totaled approximately $600 million. Of this amount, hospital and public sector receivables were approximately $330 million in the aggregate, of which approximately 14%, 27%, 46% and 13% related to Greece, Italy, Spain and Portugal, respectively. As of December 31, 2014, the Company’s total net accounts receivable outstanding for more than one year were approximately $100 million, of which approximately 31% related to accounts receivable in Greece, Italy, Spain and Portugal, mostly comprised of hospital and public sector receivables.
During 2014, the Company completed non-recourse factorings in Spain of approximately $100 million and in Italy of approximately $100 million of hospital and public sector receivables. During 2013, the Company completed non-recourse factorings of approximately $210 million of hospital and public sector receivables in Spain. During 2012, the Company collected approximately $500 million of accounts receivable in connection with the Spanish government’s debt stabilization/stimulus plan. In addition, the Company completed non-recourse factorings of approximately $230 million in 2012 of hospital and public sector accounts receivable in Italy.
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.
The Company’s customers with the largest accounts receivable balances are: AmerisourceBergen Corporation, Cardinal Health, Inc., McKesson Corporation, AAH Pharmaceuticals Ltd (U.K.) and Zuellig Pharma Ltd. (Asia Pacific), which represented, in aggregate, approximately 30% of total accounts receivable at December 31, 2014. The Company monitors the creditworthiness of its customers to which it grants credit terms in the normal course of business. Bad debts have been minimal. The Company does not normally require collateral or other security to support credit sales.
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 December 31, 2014 and 2013, the Company had received cash collateral of $1.4 billion 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 December 31, 2014 or 2013.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventories	Inventories
	Inventories at December 31 consisted of:


		2014		2013
	Finished goods	$	1,588	$	1,738

	Raw materials and work in process	5,141		5,894

	Supplies	197		225

	Total (approximates current cost)	6,926		7,857

	Increase to LIFO costs	309		73

		$	7,235	$	7,930

	Recognized as:
	Inventories	$	5,571	$	6,226

	Other assets	1,664		1,704

	Inventories valued under the LIFO method comprised approximately $2.6 billion and $2.3 billion of inventories at December 31, 2014 and 2013, respectively. Amounts recognized as Other assets are comprised almost entirely of raw materials and work in process inventories. At December 31, 2014 and 2013, these amounts included $1.6 billion and $1.5 billion, respectively, of inventories not expected to be sold within one year. In addition, these amounts included $74 million and $177 million at December 31, 2014 and 2013, respectively, of inventories produced in preparation for product launches.

Goodwill_and_Other_Intangibles

Goodwill and Other Intangibles	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	Goodwill and Other Intangibles
	The following table summarizes goodwill activity by segment:



		Pharmaceutical			All Other			Total

	Balance January 1, 2013	$	10,086		$	2,048		$	12,134

	Acquisitions	103			188			291

	Divestitures	(45		)	—			(45		)

	Other (1)	(79		)	—			(79		)

	Balance December 31, 2013	10,065			2,236			12,301

	Acquisitions	1,369			38			1,407

	Divestitures	(200		)	(362		)	(562		)
	Impairments	(93		)	—			(93		)

	Other (1)	(33		)	(28		)	(61		)
	Balance December 31, 2014 *(2)*	$	11,108		$	1,884		$	12,992

	(1) Other includes cumulative translation adjustments on goodwill balances and certain other adjustments.
	(2) Accumulated goodwill impairment losses at December 31, 2014 were $93 million.
	In 2014, the additions to goodwill in the Pharmaceutical segment primarily resulted from the acquisition of Idenix and the reductions resulted both from the sale of MCC and the divestiture of certain ophthalmic products in several international markets (see Note 4). The reductions to goodwill in other segments during 2014 resulted from the termination of the Company’s relationship with AstraZeneca LP (“AZLP”) (see Note 8) and the divestiture of MCC. Also, during the third quarter of 2014, the Company recorded an impairment charge on the goodwill related to the Supera joint venture (see Note 4).
	The Company performed its most recent annual impairment test as of October 1, 2014 and concluded that goodwill was not impaired.
	The additions to Pharmaceutical segment goodwill in 2013 resulted from the formation of the Supera joint venture (see Note 4) and the reductions resulted from the divestiture of the Company’s API manufacturing business and related branded products (see Note 3).
	In July 2013, the Company acquired the remaining shares of Physicians Interactive, a provider of on-line and mobile clinical resources and solutions for health care professionals in which Merck had an existing 24% ownership interest, for $97 million. In November 2013, Merck acquired Health Management Resources Corporation, a leader in medical weight management, for $87 million. These transactions collectively resulted in the addition of approximately $175 million of goodwill during 2013 included in other segments. Pro forma financial information has not been included for these transactions because the historical financial results are not significant when compared with the Company’s financial results.
	Other intangibles at December 31 consisted of:


		2014									2013
		Gross			Accumulated			Net			Gross		Accumulated		Net
		Carrying			Amortization						Carrying		Amortization
		Amount									Amount
	Products and product rights	$	38,714		$	23,830		$	14,884		$	41,691	$	21,216	$	20,475

	In-process research and development	4,345			—			4,345			1,856		—		1,856

	Tradenames	198			71			127			1,632		310		1,322

	Other	1,527			497			1,030			958		810		148

		$	44,784		$	24,398		$	20,386		$	46,137	$	22,336	$	23,801

	Acquired intangibles include products and product rights, tradenames and patents, which are recorded at fair value, assigned an estimated useful life, and are amortized primarily on a straight-line basis over their estimated useful lives. Some of the Company’s more significant acquired intangibles related to marketed products (included in product and product rights above) at December 31, 2014 include Zetia, $3.6 billion; Vytorin, $2.1 billion; Nasonex, $719 million; NuvaRing, $684 million; and Implanon/Nexplanon $703 million. During 2014, the Company recognized an intangible asset related to Adempas as a result of the formation of a collaboration with Bayer (see Note 4) that had a carrying value of $858 million at December 31, 2014 reflected in other in the table above. Also, during 2014, $2.2 billion of other intangible assets were divested in connection with the sale of MCC (see Note 4).
	During 2014 and 2013, the Company recorded impairment charges related to marketed products of $1.1 billion and $486 million, respectively, within Material and production costs. Of the amount recorded in 2014, $793 million related to PegIntron, $244 million related to Victrelis and $35 million related to Rebetol, all of which are products marketed by the Company for the treatment of chronic HCV. During 2014, sales of these products were adversely affected by loss of market share or patient treatment delays in markets anticipating the availability of new therapeutic options. In 2014, these trends accelerated more rapidly than previously anticipated by the Company. In addition, developments in the competitive HCV treatment market led to market share losses that were greater than the Company had predicted. These factors caused changes in cash flow projections for PegIntron, Victrelis and Rebetol that indicated the intangible asset values were not recoverable on an undiscounted cash flows basis. The Company utilized market participant assumptions to determine its best estimate of the fair values of the intangible assets related to PegIntron, Victrelis and Rebetol that, when compared with their related carrying values, resulted in the impairment charges noted above. Of the amount recorded in 2013, $330 million resulted from lower cash flow projections for Saphris/Sycrest, due to reduced expectations in international markets and in the United States. These revisions to cash flows indicated that the Saphris/Sycrest intangible asset value was not recoverable on an undiscounted cash flows basis. The Company utilized market participant assumptions and considered several different scenarios to determine its best estimate of the fair value of the intangible asset related to Saphris/Sycrest that, when compared with its related carrying value, resulted in the impairment charge noted above. The remaining $156 million of impairment charges in 2013 resulted from lower cash flow projections for Rebetol due to reduced expectations in Japan and Europe. These revisions to cash flows indicated that the Rebetol intangible asset value was not recoverable on an undiscounted cash flows basis. The Company utilized market participant assumptions to determine its best estimate of the fair value of the intangible asset related to Rebetol that, when compared with its related carrying value, resulted in the impairment charge noted above.
	IPR&D that the Company acquires through business combinations represents the fair value assigned to incomplete research projects which, at the time of acquisition, have not reached technological feasibility. Amounts capitalized as IPR&D are accounted for as indefinite-lived intangible assets, subject to impairment testing until completion or abandonment of the projects. During 2014, the Company recorded IPR&D of $3.2 billion related to the acquisition of Idenix (see Note 4). Upon successful completion of each project, the Company will make a separate determination as to the then useful life of the assets and begin amortization. During 2014, 2013 and 2012, $654 million, $346 million and $78 million, respectively, of IPR&D was reclassified to products and product rights upon receipt of marketing approval in a major market.
	During 2014, the Company recorded $49 million of IPR&D impairment charges within Research and development expenses primarily as a result of changes in cash flow assumptions for certain compounds obtained in connection with the Supera joint venture, as well as for the discontinuation of certain Animal Health programs. During 2013, the Company recorded $279 million of IPR&D impairment charges. Of this amount, $181 million related to the write-off of the intangible asset associated with preladenant as a result of the discontinuation of the clinical development program for this compound. In addition, the Company recorded impairment charges resulting from changes in cash flow assumptions for certain compounds, as well as for pipeline programs that had previously been deprioritized and were subsequently deemed to have no alternative use in the period. During 2012, the Company recorded $200 million of IPR&D impairment charges primarily for pipeline programs that had previously been deprioritized and were subsequently deemed to have no alternative use during the period.
	All of the IPR&D projects that remain in development are subject to the inherent risks and uncertainties in drug development and it is possible that the Company will not be able to successfully develop and complete the IPR&D programs and profitably commercialize the underlying product candidates.
	The Company may recognize additional non-cash impairment charges in the future related to other marketed products or pipeline programs and such charges could be material.
	Aggregate amortization expense primarily recorded within Materials and production costs was $4.2 billion in 2014, $4.8 billion in 2013 and $5.0 billion in 2012. The estimated aggregate amortization expense for each of the next five years is as follows: 2015, $3.9 billion; 2016, $3.2 billion; 2017, $2.9 billion; 2018, $1.4 billion; 2019, $638 million.

Joint_Ventures_and_Other_Equit

Joint Ventures and Other Equity Method Affiliates	12 Months Ended
	Dec. 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:


	Years Ended December 31	2014			2013		2012
	AstraZeneca LP (1)	$	192		$	352	$	621

	Other (2)	65			52		21

		$	257		$	404	$	642


	(1)	As noted below, as of July 1, 2014, the Company no longer records equity income from AZLP.

	(2)	Includes results from Sanofi Pasteur MSD.

	AstraZeneca LP
	In 1982, Merck entered into an agreement with Astra AB (“Astra”) to develop and market Astra products under a royalty-bearing license. In 1993, Merck’s total sales of Astra products reached a level that triggered the first step in the establishment of a joint venture business carried on by Astra Merck Inc. (“AMI”), in which Merck and Astra each owned a 50% share. This joint venture, formed in 1994, developed and marketed most of Astra’s new prescription medicines in the United States.
	In 1998, Merck and Astra completed the restructuring of the ownership and operations of the joint venture whereby Merck acquired Astra’s interest in AMI, renamed 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.
	Merck earned revenue based on sales of KBI products and such revenue was $463 million, $920 million and $915 million in 2014, 2013 and 2012, respectively, primarily relating to sales of Nexium, as well as Prilosec. In addition, Merck earned certain Partnership returns, which were recorded in Equity income from affiliates, as reflected in the table above. Such returns included a priority return provided for in the Partnership Agreement, a preferential return representing Merck’s share of undistributed AZLP GAAP earnings, and a variable return related to the Company’s 1% limited partner interest.
	On June 30, 2014, AstraZeneca exercised its option to purchase Merck’s interest in KBI for $419 million in cash. Of this amount, $327 million reflects an estimate of the fair value of Merck’s interest in Nexium and Prilosec. This portion of the exercise price, which is subject to a true-up in 2018 based on actual sales from closing in 2014 to June 2018, was deferred and is being recognized over time in Other (income) expense, net as the contingency is eliminated as sales occur. During 2014, $140 million of the deferred revenue was recognized in Other (income) expense, net. The remaining exercise price of $91 million primarily represents a multiple of ten times Merck’s average 1% annual profit allocation in the partnership for the three years prior to exercise. Merck recognized the $91 million as a gain in 2014 within Other (income) expense, net. As a result of AstraZeneca’s option exercise, the Company’s remaining interest in AZLP was redeemed. Accordingly, the Company also recognized a non-cash gain of approximately $650 million in 2014 within Other (income) expense, net resulting from the retirement of $2.4 billion of KBI preferred stock (see Note 11), the elimination of the Company’s $1.4 billion investment in AZLP and a $340 million reduction of goodwill. This transaction resulted in a net tax benefit of $517 million in 2014 primarily reflecting the reversal of deferred taxes on the AZLP investment balance.
	As a result of AstraZeneca exercising its option, as of July 1, 2014, the Company no longer records equity income from AZLP and supply sales to AZLP have terminated.
	Summarized financial information for AZLP is as follows:


	Years Ended December 31	2014 *(1)*			2013		2012
	Sales	$	2,205		$	4,611	$	4,694

	Materials and production costs	1,044			2,222		2,177

	Other expense, net	604			1,175		1,312

	Income before taxes (2)	557			1,214		1,205



	December 31	2013
	Current assets	$	4,832

	Noncurrent assets	182

	Current liabilities	3,958

	(1) Includes results through the June 30, 2014 termination date.
	(2) Merck’s partnership returns from AZLP were generally contractually determined as noted above and were not based on a percentage of income from AZLP, other than with respect to Merck’s 1% limited partnership interest.
	Sanofi Pasteur MSD
	In 1994, Merck and Pasteur Mérieux Connaught (now Sanofi Pasteur S.A.) established an equally-owned joint venture to market vaccines in Europe and to collaborate in the development of combination vaccines for distribution in Europe. Joint venture vaccine sales were $1.1 billion for 2014, $1.2 billion for 2013 and $1.1 billion for 2012.
	Investments in affiliates accounted for using the equity method, including the above joint ventures, totaled $337 million at December 31, 2014 and $1.6 billion at December 31, 2013. These amounts are reported in Other assets. Amounts due from the above joint ventures included in Deferred income taxes and other current assets were $45 million at December 31, 2014 and $277 million at December 31, 2013.
	Summarized information for those affiliates (excluding AZLP disclosed separately above) is as follows:


	Years Ended December 31	2014			2013		2012
	Sales	$	1,370		$	1,326	$	1,295

	Materials and production costs	577			581		573

	Other expense, net	641			691		705

	Income before taxes	152			54		17



	December 31	2014			2013
	Current assets	$	1,819		$	1,486

Noncurrent assets	208			149

Current liabilities	469			456

Noncurrent liabilities	129			154

Loans_Payable_LongTerm_Debt_an

Loans Payable, Long-Term Debt and Other Commitments	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Loans Payable, Long-Term Debt and Other Commitments	Loans Payable, Long-Term Debt and Other Commitments
	Loans payable at December 31, 2014 included $1.0 billion of notes due in 2015, $1.5 billion of commercial paper, $55 million of short-term foreign borrowings and $143 million of long-dated notes that are subject to repayment at the option of the holder. Loans payable at December 31, 2013 included $2.1 billion of notes due in 2014, $1.6 billion of commercial paper, $402 million of short-term foreign borrowings and $370 million of long-dated notes that are subject to repayment at the option of the holders. The weighted-average interest rate of the commercial paper borrowings was 0.15% and 0.09% at December 31, 2014 and 2013, respectively.
	Long-term debt at December 31 consisted of:


		2014		2013
	2.80% notes due 2023	$	1,749	$	1,749

	5.00% notes due 2019	1,291		1,293

	4.15% notes due 2043	1,246		1,246

	1.125% euro-denominated notes due 2021	1,218		—

	1.875% euro-denominated notes due 2026	1,210		—

	3.875% notes due 2021	1,150		1,148

	2.40% notes due 2022	1,000		1,000

	Floating-rate borrowing due 2018	1,000		1,000

	1.10% notes due 2018	999		998

	0.70% notes due 2016	998		997

	1.30% notes due 2018	984		975

	2.25% notes due 2016	858		866

	6.50% notes due 2033	812		1,306

	2.50% euro-denominated notes due 2034	603		—

	6.55% notes due 2037	597		1,143

	Floating-rate borrowing due 2016	500		500

	3.60% notes due 2042	493		492

	5.85% notes due 2039	418		749

	5.75% notes due 2036	371		498

	5.95% debentures due 2028	356		498

	6.40% debentures due 2028	326		499

	6.30% debentures due 2026	152		249

	6.00% notes due 2017	—		1,095

	4.00% notes due 2015	—		1,029

	4.75% notes due 2015	—		1,023

	Other	368		186

		$	18,699	$	20,539

	Other (as presented in the table above) included $309 million and $119 million at December 31, 2014 and 2013, respectively, of borrowings at variable rates averaging 0.0% for 2014 and 2013. Other also included foreign borrowings of $53 million and $64 million at December 31, 2014 and 2013, respectively, at varying rates up to 6.25% and 4.50%, respectively.
	With the exception of the 6.30% debentures due 2026, the notes listed in the table above are redeemable in whole or in part, at Merck’s option at any time, at varying redemption prices.
	In October 2014, the Company issued euro-denominated senior unsecured notes consisting of €1.0 billion principal amount of 1.125% notes due 2021, €1.0 billion principal amount of 1.875% notes due 2026 and €500 million principal amount of 2.5% notes due 2034. Interest on the notes is payable annually. The notes of each series are redeemable in whole or in part at any time at the Company’s option at varying redemption prices. The net proceeds of the offering of $3.1 billion were used in part to repay debt that was validly tendered in connection with tender offers launched by the Company for certain outstanding notes and debentures. The Company paid $2.5 billion in aggregate consideration (applicable purchase price together with accrued interest) to redeem $1.8 billion principal amount of debt. In addition, in November 2014, Merck redeemed its $1.0 billion 4.00% notes due 2015 and its $1.0 billion 6.00% notes due 2017. The Company recorded a pretax loss of $628 million in 2014 in connection with these transactions.
	In February 2015, Merck issued $8.0 billion aggregate principal amount of senior unsecured notes consisting of $300 million principal amount of floating rate notes due 2017, $700 million principal amount of floating rate notes due 2020, $1.25 billion principal amount of 1.85% notes due 2020, $1.25 billion aggregate principal amount of 2.35% notes due 2022, $2.5 billion aggregate principal amount of 2.75% notes due 2025 and $2.0 billion aggregate principal amount of 3.70% notes due 2045. The Company used a substantial portion of the net proceeds of the offering to repay commercial paper issued to substantially finance the Company’s acquisition of Cubist. Any remaining net proceeds will be used for general corporate purposes, including without limitation repurchases of the Company’s common stock, and the repayment of outstanding commercial paper borrowings and upcoming debt maturities.
In December 2014, the Company entered into a bridge loan agreement with certain banks pursuant to which the Company had the ability to borrow up to $8.0 billion for the purpose of obtaining short-term financing for the acquisition of Cubist. The Company did not borrow any funds under the bridge loan and, after issuing $8.0 billion of senior unsecured notes as discussed above, terminated the bridge loan on February 20, 2015.
Effective as of November 3, 2009, the Company executed a full and unconditional guarantee of the then existing debt of its subsidiary Merck Sharp & Dohme Corp. (“MSD”) and MSD executed a full and unconditional guarantee of the then existing debt of the Company (excluding commercial paper), including for payments of principal and interest. These guarantees do not extend to debt issued subsequent to that date.
Certain of the Company’s borrowings require that Merck comply with financial covenants including a requirement that the Total Debt to Capitalization Ratio (as defined in the applicable agreements) not exceed 60%. At December 31, 2014, the Company was in compliance with these covenants.
The aggregate maturities of long-term debt for each of the next five years are as follows: 2015, $1.0 billion; 2016, $2.4 billion; 2017, $19 million; 2018, $3.0 billion; 2019, $1.3 billion. These amounts do not reflect debt maturities related to the Company’s February 2015 debt issuance described above.
In August 2014, the Company terminated its existing credit facility and entered into a new $6.0 billion, five-year credit facility that matures in August 2019. The facility provides backup liquidity for the Company’s commercial paper borrowing facility and is to be used for general corporate purposes. The Company has not drawn funding from this facility.
Rental expense under operating leases, net of sublease income, was $350 million in 2014, $367 million in 2013 and $396 million in 2012. The minimum aggregate rental commitments under noncancellable leases are as follows: 2015, $232 million; 2016, $122 million; 2017, $92 million; 2018, $55 million; 2019, $46 million and thereafter, $97 million. The Company has no significant capital leases.

Contingencies_and_Environmenta

Contingencies and Environmental Liabilities	12 Months Ended
Contingencies and Environmental Liabilities	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Contingencies and Environmental Liabilities	Contingencies and Environmental Liabilities
	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 certain additional matters including 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 25 active federal and state lawsuits (the “Vioxx Product Liability Lawsuits”) alleging personal injury as a result of the use of Vioxx. Most of these 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.
	As previously disclosed, Merck is also a defendant in approximately 30 putative class action lawsuits alleging economic injury as a result of the purchase of Vioxx. All but one of those cases are in the Vioxx MDL. Merck has reached a resolution, approved by Judge Fallon, of these class actions in the Vioxx MDL. 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 in January 2014.
	Merck is also a defendant in lawsuits brought by state Attorneys General of three states — Alaska, Montana and Utah. These actions were pending in the Vioxx MDL proceeding, but on October 10, 2014, the Judicial Panel on Multidistrict Litigation (“JPML”) issued an order remanding the actions back to their original federal courts. These actions allege that Merck misrepresented the safety of Vioxx and seek recovery for expenditures on Vioxx by government-funded health care programs, such as Medicaid, and/or penalties for alleged Consumer Fraud Act violations. On February 6, 2015, the federal district judge in Anchorage remanded the Alaska lawsuit to state court. The Montana Attorney General has filed a renewed motion to remand its case from the federal district court to Montana state court, but the motion has not yet been decided.

	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. 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,” together with the prior individual actions, the “Direct Actions”) 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 of the Direct 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 in the Direct Actions and is now closed. Dispositive motions have been fully briefed in the Direct Actions. Between March 2014 and February 2015, six 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 Direct Actions and are consolidated with the Vioxx Securities Lawsuits.

	Insurance
	The Company has Directors and Officers insurance coverage applicable to the Vioxx Securities Lawsuits with remaining stated upper limits of approximately $145 million. 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 December 31, 2014, approximately 5,575 cases, which include approximately 5,805 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 1,015 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; however, substantially all of those actions are subject to the settlement discussed below. In addition, plaintiffs in approximately 4,560 of these actions generally allege that they sustained femur fractures and/or other bone injuries (“Femur Fractures”) in association with the use of Fosamax.

	Cases Alleging ONJ and/or Other Jaw Related Injuries
	In August 2006, the 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.
	In December 2013, Merck reached an agreement in principle with the Plaintiffs’ Steering Committee (“PSC”) in the Fosamax ONJ MDL 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. Merck and the PSC subsequently formalized the terms of this agreement in a Master Settlement Agreement (“ONJ Master Settlement Agreement”) that was executed in April 2014. As a condition to the settlement, 100% of the state and federal ONJ plaintiffs had to agree to participate in the settlement plan or Merck could either terminate the ONJ Master Settlement Agreement, or waive the 100% participation requirement and agree to a lesser funding amount for the settlement fund. On July 14, 2014, Merck elected to proceed with the ONJ Master Settlement Agreement at a reduced funding level since the current participation level is approximately 95%. In addition, the judge overseeing the Fosamax ONJ MDL granted a motion filed by Merck and has entered an order that requires the approximately 30 non-participants whose cases remain in the Fosamax ONJ MDL to submit expert reports in order for their cases to proceed any further. The ONJ Master Settlement Agreement has no effect on the cases alleging Femur Fractures discussed below.

	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 1,035 cases were pending in the Fosamax Femur Fracture MDL as of December 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.
	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. 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. Furthermore, on June 17, 2014, Judge Pisano granted Merck summary judgment in the Gaynor v. Merck case and found that Merck’s updates in January 2011 to the Fosamax label regarding atypical femur fractures were adequate as a matter of law and that Merck adequately communicated those changes. The plaintiffs in Gaynor have appealed Judge Pisano’s decision to the Third Circuit. In August 2014, Merck filed a motion requesting that Judge Pisano enter a further order requiring all remaining plaintiffs in the Fosamax Femur Fracture MDL who claim that the 2011 Fosamax label is inadequate and the proximate cause of their alleged injuries to show cause why their cases should not be dismissed based on the court’s preemption decision and its ruling in the Gaynor case. Plaintiffs opposed that motion and asked the court to stay the remaining cases in the Fosamax Femur Fracture MDL until the Third Circuit rules on their appeal of Judge Pisano’s preemption decision, but Judge Pisano granted Merck’s motion and entered the requested show cause order in November 2014. In September 2014, Judge Pisano also ordered the parties to participate in a mediation process.
	As of December 31, 2014, approximately 3,005 cases alleging Femur Fractures have been filed in New Jersey state court and are pending before Judge Jessica Mayer in Middlesex County. 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 December 31, 2014, approximately 515 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 Thierry Colaw is currently presiding over the coordinated proceedings. In March 2014, the court directed that a group of 10 discovery pool cases be reviewed through fact discovery and subsequently scheduled the Galper v. Merck case as the first trial for February 2015. Two additional trials are scheduled for May and July 2015.
	Additionally, there are four 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 December 31, 2014, approximately 785 product user claims 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 December 31, 2014, to toll the statute of limitations for 19 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.
	Pursuant to a settlement agreement between Merck and negotiating plaintiffs’ counsel, which became effective as of June 4, 2014, Merck paid a lump total settlement of $100 million to resolve more than 95% of the cases filed and under retainer by counsel as of February 7, 2014. Plaintiffs in 1,868 cases have joined the settlement program. Those cases will be dismissed with prejudice once the settlement administration process is completed. The Company expects the first dismissals to begin in the second quarter and continue on a rolling basis throughout 2015. 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 has also been used to fund the settlement.
	As of December 31, 2014, approximately 80 cases outside of the settlement program remained. Any plaintiff not participating in the settlement who chooses to proceed with their case, as well as any future plaintiffs, in the NuvaRing MDL or New Jersey state court are and will be obligated to meet various discovery and evidentiary requirements under the case management orders of the NuvaRing MDL and New Jersey state court. Plaintiffs who fail to fully and timely satisfy these requirements under set deadlines will be subject to an Order to Show Cause why their case should not be dismissed with prejudice.

	Propecia/Proscar
	As previously disclosed, Merck is a defendant in product liability lawsuits in the United States involving Propecia and/or Proscar. As of December 31, 2014, approximately 1,235 lawsuits involving a total of approximately 1,500 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 50 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. The Company intends to defend against these lawsuits.

	Governmental Proceedings
	As previously disclosed, on June 21, 2012, the U.S. District Court for the Eastern District of Pennsylvania unsealed a complaint that has been filed against the Company under the federal False Claims Act by two former employees alleging, among other things, that the Company defrauded the U.S. government by falsifying data in connection with a clinical study conducted on the mumps component of the Company’s M-M-R II vaccine. The complaint alleges the fraud took place between 1999 and 2001. The U.S. government had the right to participate in and take over the prosecution of this lawsuit, but has notified the court that it declined to exercise that right. The two former employees are pursuing the lawsuit without the involvement of the U.S. government. In addition, two putative class action lawsuits on behalf of direct purchasers of the M‑M‑R II vaccine which charge that the Company misrepresented the efficacy of the M-M-R II vaccine in violation of federal antitrust laws and various state consumer protection laws are pending in the Eastern District of Pennsylvania. On September 4, 2014, the Court denied Merck’s motion to dismiss the False Claims Act suit and granted in part and denied in part its motion to dismiss the then-pending antitrust suit. As a result, both the False Claims Act suit and the antitrust suits will now proceed into discovery. The Company intends to defend against these lawsuits.
	As previously disclosed, the Company has received a subpoena from the Office of Inspector General of the U.S. Department of Health and Human Services on behalf of the U.S. Attorney’s Office for the District of Maryland and the Civil Division of the U.S. Department of Justice (the “DOJ”) which requests information relating to the Company’s marketing of Singulair and Dulera Inhalation Aerosol and certain of its other marketing activities from January 1, 2006 to the present. The Company is cooperating with the government.
	Prior to the Company’s acquisition of Cubist, Cubist acquired Optimer Pharmaceuticals, Inc. (“Optimer”). As previously disclosed by Cubist, prior to its acquisition of Optimer, Optimer became aware of an attempted share grant in September 2011 by Optimer’s then-subsidiary, OBI Pharma, Inc. and certain related matters, including a potentially improper $300 thousand payment to a research laboratory in July 2011 involving an individual associated with the share grant, that may have violated certain applicable laws, including the U.S. Foreign Corrupt Practices Act. In April 2012, Optimer self-reported the results of its preliminary findings to the U.S. Securities and Exchange Commission (the “SEC”) and the DOJ, terminated its then-Chief Financial Officer and then-Vice President, Clinical Development, and removed the Chairman of its Board of Directors. In February 2013, the independent members of Optimer’s Board of Directors determined that additional remedial action should be taken in light of prior compliance, record keeping and conflict-of-interest issues surrounding the potentially improper payment to the research laboratory and certain related matters. On February 26, 2013, Optimer’s then-President and Chief Executive Officer and its then-General Counsel and Chief Compliance Officer resigned at the request of the independent members of the Board of Directors.
	The Company is continuing to cooperate with the investigations by the relevant U.S. authorities in their review of these matters, and Optimer had taken remedial steps in response to its internal investigation prior to the Cubist acquisition. Nonetheless, these events could result in lawsuits being filed against Optimer and certain of Optimer’s former employees and directors. The Company may be required to indemnify such persons for any costs or losses incurred in connection with such proceedings. The Company cannot predict the ultimate resolution of these matters, whether Optimer or such persons will be charged with violations of applicable civil or criminal laws or whether the scope of the investigations will be extended to new issues. The Company also cannot predict what potential penalties or other remedies, if any, the authorities may seek or what the collateral consequences may be of any such government actions.
	As previously disclosed, the Company has received letters from the DOJ and the SEC that seek information about activities in a number of countries and reference the Foreign Corrupt Practices Act. The Company has cooperated with the agencies in their requests and believes that this inquiry is part of a broader review of pharmaceutical industry practices in foreign countries. As previously disclosed, the Company has been advised by the DOJ that, based on the information that it has received, it has closed its inquiry into this matter as it relates to the Company. In the future, the Company may receive additional requests for information from either or both of the DOJ and the SEC.
	As previously disclosed, 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.

	Commercial Litigation
	AWP Litigation
	As previously disclosed, in the past, the Company and/or certain of its subsidiaries have been named as defendants in cases brought by various states alleging manipulation by pharmaceutical manufacturers of Average Wholesale Prices (“AWP”), which are sometimes used by public and private payors in calculating provider reimbursement levels. In 2014, the Company settled the remaining AWP cases in which it or a subsidiary was a defendant.

K-DUR Antitrust Litigation
As previously disclosed, in June 1997 and January 1998, Schering-Plough settled patent litigation with Upsher-Smith, Inc. (“Upsher-Smith”) and ESI Lederle, Inc. (“Lederle”), respectively, relating to generic versions of K-DUR, Schering-Plough’s long-acting potassium chloride product supplement used by cardiac patients, for which Lederle and Upsher-Smith had filed Abbreviated New Drug Applications (“ANDAs”). Following the commencement of an administrative proceeding by the U.S. Federal Trade Commission (the “FTC”) in 2001 alleging anti-competitive effects from those settlements (which has been resolved in Schering-Plough’s favor), putative class and non-class action suits were filed on behalf of direct and indirect purchasers of K-DUR against Schering-Plough, Upsher-Smith and Lederle and were consolidated in a multi-district litigation in the U.S. District Court for the District of New Jersey. These suits claimed violations of federal and state antitrust laws, as well as other state statutory and common law causes of action, and sought unspecified damages. In April 2008, the indirect purchasers voluntarily dismissed their case. In March 2010, the District Court granted summary judgment to the defendants on the remaining lawsuits and dismissed the matter in its entirety. In July 2012, the Third Circuit Court of Appeals reversed the District Court’s grant of summary judgment and remanded the case for further proceedings. At the same time, the Third Circuit upheld a December 2008 decision by the District Court to certify certain direct purchaser plaintiffs’ claims as a class action.
In August 2012, the Company filed a petition for certiorari with the U.S. Supreme Court seeking review of the Third Circuit’s decision. In June 2013, the Supreme Court granted that petition, vacated the judgment of the Third Circuit, and remanded the case for further consideration in light of its recent decision in FTC v. Actavis, Inc. That decision held that whether a so-called “reverse payment” — i.e., a payment from the holder of a pharmaceutical patent to a party challenging the patent made in connection with a settlement of their dispute — violates the antitrust laws should be determined on the basis of a “rule of reason” analysis. In September 2013, the Third Circuit returned the case to the District Court for further proceedings in accordance with the Actavis standard.

Sales Force Litigation
As previously disclosed, in May 2013, Ms. Kelli Smith filed a complaint against the Company in the United States District Court for the District of New Jersey of behalf of herself and a putative class of female sales representatives and a putative sub-class of female sales representatives with children, claiming (a) discriminatory policies and practices in selection, promotion and advancement, (b) disparate pay, (c) differential treatment, (d) hostile work environment and (e) retaliation under federal and state discrimination laws. In November 2013, the Company filed a motion to dismiss the class claims. Plaintiffs sought and were granted leave to file an amended complaint. In January 2014, plaintiffs filed an amended complaint adding four additional named plaintiffs. On October 8, 2014, the court denied the Company’s motion to dismiss or strike the class claims as premature.

Patent Litigation
From time to time, generic manufacturers of pharmaceutical products file ANDAs with 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, Cubicin, Emend for Injection, Invanz, Nasonex, 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. In August 2014, a patent infringement lawsuit was filed in the United States against Fresenius Kabi USA, LLC (“Fresenius”) in respect of Fresenius’s application to the FDA seeking pre-patent expiry approval to market a generic version of Cancidas. The lawsuit automatically stays FDA approval of Fresenius’s application until December 2016 or until an adverse court decision, if any, whichever may occur earlier.
Cubicin — In March 2012, a patent infringement lawsuit was filed in the United States against Hospira, Inc. (“Hospira”), with respect to Hospira’s application to the FDA seeking pre-patent expiry approval to market a generic version of Cubicin. A trial was held in February 2014, and in December 2014 the district court found the composition patent, which expires in June 2016, to be valid and infringed. Later patents, expiring in September 2019 and November 2020, were found to be invalid. Hospira has appealed the finding that the composition patent is not invalid and the Company has cross-appealed the finding that the later patents are invalid. If the decision is upheld on appeal, Hospira’s application will not be approved until at least June 2016.
In October 2013, a patent infringement lawsuit was filed in the United States against Strides, Inc. and Agila Specialties Private Limited (“Strides/Agila”), with respect to Strides/Agila’s application to the FDA seeking pre-patent expiry approval to market a generic version of Cubicin. The lawsuit automatically stays FDA approval of Strides/Agila’s application until February 2016 or until an adverse court decision, if any, whichever may occur earlier. If the Hospira decision is upheld on appeal, Strides/Agila’s application will not be approved until at least June 2016.
In July 2014, a patent infringement lawsuit was filed in the United States against Fresenius Kabi USA, LLC. (“Fresenius”), with respect to Fresenius’s application to the FDA seeking pre-patent expiry approval to market a generic version of Cubicin. The lawsuit automatically stays FDA approval of Fresenius’s application until November 2016 or until an adverse court decision, if any, whichever may occur earlier. If the Hospira decision is upheld on appeal, Fresenius’s application will not be approved until at least June 2016.
An earlier district court action against Teva Parenteral Medicines Inc., Teva Pharmaceuticals USA, Inc. and Teva Pharmaceutical Industries Ltd. (collectively, “Teva”) resulted in a settlement whereby Teva can launch in December 2017 (June 2018 if the Company obtains pediatric marketing exclusivity on Cubicin). If the Hospira decision is upheld on appeal, Teva will be able to launch in June 2016.
In October 2014, Agila Specialties Inc. and Mylan Pharmaceuticals Inc. filed petitions for Inter Partes Review (“IPR”) at the United States Patent and Trademark Office (“USPTO”) seeking the invalidity of the September 2019 and November 2020 patents. In November 2014, Fresenius filed petitions for IPR at the USPTO seeking the invalidity of the September 2019 patents. The USPTO has six months from filing to determine whether it will institute the requested IPR proceedings.
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. In July 2014, a patent infringement lawsuit was filed in the United States against Fresenius in respect of Fresenius’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 Fresenius’s application until November 2016 or until an adverse court decision, if any, whichever may occur earlier. In December 2014, Apotex Inc. filed a petition for IPR at the USPTO seeking the invalidity of claims in the compound patent covering Emend for Injection. The USPTO has six months to determine whether it will institute the requested IPR proceedings.
Invanz — In July 2014, a patent infringement lawsuit was filed in the United States against Hospira in respect of Hospira’s application to the FDA seeking pre-patent expiry approval to market a generic version of Invanz. The lawsuit automatically stays FDA approval of Hospira’s application until November 2016 or until an adverse court decision, if any, whichever may occur earlier. Also in July 2014, a patent infringement lawsuit was filed in the United States against Sandoz in respect to Sandoz’s application to the FDA seeking pre-patent approval to market a generic version of Invanz. As neither Hospira nor Sandoz challenged an earlier patent covering Invanz, both parties’ application to the FDA will not be approved until at least that patent expires in May 2016.
Nasonex — In July 2014, a patent infringement lawsuit was filed in the United States against Teva Pharmaceuticals USA, Inc. (“Teva Pharma”) in respect of Teva Pharma’s application to the FDA seeking pre-patent expiry approval to market a generic version of Nasonex. The lawsuit automatically stays FDA approval of Teva Pharma’s application until November 2016 or until an adverse court decision, if any, whichever may occur earlier. A decision issued in June 2013 held that the same Merck patent covering mometasone furoate monohydrate was valid, but that it was not infringed by Apotex Corp.’s proposed product.
NuvaRing — In December 2013, the Company filed a lawsuit against a subsidiary of Actavis plc in the United States in respect of that company’s application to the FDA seeking pre-patent expiry approval to sell a generic version of NuvaRing.

Anti-PD-1 Antibody Patent Oppositions and Litigation
As previously disclosed, Ono Pharmaceutical Co. (“Ono”) has a European patent (EP 1 537 878) (“’878”) that broadly claims the use of an anti-PD-1 antibody, such as the Company’s immunotherapy, Keytruda, 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 the ’878 patent is invalid and filed an opposition in the European Patent Office (the “EPO”) seeking its revocation. In June 2014, the Opposition Division of the EPO found the claims in the ’878 patent are valid. The Company received the Opposition Division’s written opinion in September 2014 and the Company submitted its substantive appeal in February 2015. In April 2014, the Company, and three other companies, opposed another European patent (EP 2 161 336) (“’336”) owned by BMS and Ono that it believes is invalid. The ’336 patent, if valid, broadly claims anti-PD-1 antibodies that could include Keytruda. BMS and Ono recently submitted a request to amend the claims of the ’336 patent. If the EPO allows this amendment, the claims of the ’336 patent would no longer broadly claim anti-PD-1 antibodies such as Keytruda.
In May 2014, the Company filed a lawsuit in the United Kingdom (“UK”) seeking revocation of the UK national versions of both the ’878 and ’336 patents. In July 2014, Ono and BMS sued the Company seeking a declaration that the ’878 patent would be infringed in the UK by the marketing of Keytruda. The Company has sought a declaration from the UK court that Keytruda will not infringe the ’336 patent in the UK. It is anticipated that the issues of validity and infringement of both patents will be heard at the same time by the UK court, which has scheduled the trial to begin in July 2015. BMS and Ono recently notified the Company of their request to amend the claims of the EPO ’336 patent and of their intention to seek permission from the court to similarly amend the UK national version so that the claims of the ’336 patent would no longer broadly claim anti-PD-1 antibodies such as Keytruda.
The Company can file lawsuits seeking revocation of the ’336 and ’878 patents in other national courts in Europe at any time, and Ono and BMS can file patent infringement actions against the Company in other national courts in Europe at or around the time the Company launches Keytruda (if approved). If a national court determines that the Company infringed a valid claim in the ’878 or ’336 patent, Ono and BMS may be entitled to monetary damages, including royalties on future sales of Keytruda, and potentially could seek an injunction to prevent the Company from marketing Keytruda in that country.
The USPTO granted US Patent Nos. 8,728,474 to Ono and 8,779,105 to Ono and BMS. These patents are equivalent to the ’878 and ’336 patents, respectively. In September 2014, BMS and Ono filed a lawsuit in the United States alleging that, by marketing Keytruda, the Company will infringe US Patent No. 8,728,474. BMS and Ono are not seeking to prevent or stop the marketing of Keytruda in the United States. The trial in this matter is currently scheduled to begin in November 2016. The Company believes that the 8,728,474 patent and the 8,779,105 patent are both invalid.
In September 2014, the Company filed a lawsuit in Australia seeking the revocation of Australian patent No. 2011203119, which is equivalent to the ’336 patent.
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 Keytruda in any country in which it is approved and that it will not be prevented from doing so by the Ono or BMS patents or any pending applications.

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 December 31, 2014 and December 31, 2013 of approximately $215 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.

Environmental Matters
Merck's facilities in Oss, the Netherlands, were inspected by the Province of Brabant (the “Province”) pursuant to the Dutch Hazards of Major Accidents Decree and the sites’ environmental permits. The Province issued penalties for alleged violations of regulations governing preventing and managing accidents with hazardous substances, and the government also issued a fine for alleged environmental violations at one of the Oss facilities, which together totaled $235 thousand. The Company was subsequently advised that a criminal investigation has been initiated based upon certain of the issues that formed the basis of the administrative enforcement action by the Province. The Company intends to defend itself against any enforcement action that may result from this investigation.
The Company and its subsidiaries are parties to a number of proceedings brought under the Comprehensive Environmental Response, Compensation and Liability Act, commonly known as Superfund, and other federal and state equivalents. These proceedings seek to require the operators of hazardous waste disposal facilities, transporters of waste to the sites and generators of hazardous waste disposed of at the sites to clean up the sites or to reimburse the government for cleanup costs. The Company has been made a party to these proceedings as an alleged generator of waste disposed of at the sites. In each case, the government alleges that the defendants are jointly and severally liable for the cleanup costs. Although joint and several liability is alleged, these proceedings are frequently resolved so that the allocation of cleanup costs among the parties more nearly reflects the relative contributions of the parties to the site situation. The Company’s potential liability varies greatly from site to site. For some sites the potential liability is de minimis and for others the final costs of cleanup have not yet been determined. While it is not feasible to predict the outcome of many of these proceedings brought by federal or state agencies or private litigants, in the opinion of the Company, such proceedings should not ultimately result in any liability which would have a material adverse effect on the financial position, results of operations, liquidity or capital resources of the Company. The Company has taken an active role in identifying and providing for these costs and such amounts do not include any reduction for anticipated recoveries of cleanup costs from former site owners or operators or other recalcitrant potentially responsible parties.
In management’s opinion, the liabilities for all environmental matters that are probable and reasonably estimable have been accrued and totaled $125 million and $213 million at December 31, 2014 and 2013, respectively. These liabilities are undiscounted, do not consider potential recoveries from other parties and will be paid out over the periods of remediation for the applicable sites, which are expected to occur primarily over the next 15 years. Although it is not possible to predict with certainty the outcome of these matters, or the ultimate costs of remediation, management does not believe that any reasonably possible expenditures that may be incurred in excess of the liabilities accrued should exceed $66 million in the aggregate. Management also does not believe that these expenditures should result in a material adverse effect on the Company’s financial position, results of operations, liquidity or capital resources for any year.

Equity

Equity	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Equity	Equity
	The Merck certificate of incorporation authorizes 6,500,000,000 shares of common stock and 20,000,000 shares of preferred stock.

	Capital Stock
	A summary of common stock and treasury stock transactions (shares in millions) is as follows:


		2014			2013			2012
		Common	Treasury		Common	Treasury		Common	Treasury
		Stock	Stock		Stock	Stock		Stock	Stock
	Balance January 1	3,577	650		3,577	550		3,577	536

	Purchases of treasury stock (1)	—	134		—	139		—	62

	Issuances (2)	—	(45	)	—	(39	)	—	(48	)

	Balance December 31	3,577	739		3,577	650		3,577	550


	(1)	Purchases of treasury stock in 2013 include 105 million shares purchased pursuant to an accelerated share repurchase agreement as discussed below.

	(2)	Issuances primarily reflect activity under share-based compensation plans.
	In 2013, pursuant to an accelerated share repurchase (“ASR”) agreement with Goldman, Sachs & Co., the Company purchased 105 million shares of Merck common stock for $5.0 billion. The ASR was entered into pursuant to a share repurchase program announced on May 1, 2013.

	Noncontrolling Interests
	In connection with the 1998 restructuring of AMI, Merck assumed $2.4 billion par value preferred stock with a dividend rate of 5% per annum, which was carried by KBI and included in Noncontrolling interests at December 31, 2013. In 2014, AstraZeneca exercised its option to acquire Merck’s interest in AZLP (see Note 8) and this preferred stock obligation was retired.

ShareBased_Compensation_Plans

Share-Based Compensation Plans	12 Months Ended
	Dec. 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. The Company also issues RSUs to employees of certain of the Company’s equity method investees. In addition, employees and non-employee directors may be granted options to purchase shares of Company common stock at the fair market value at the time of grant. These plans were approved by the Company’s shareholders.
	At December 31, 2014, 139 million shares collectively were authorized for future grants under the Company’s share-based compensation plans. These awards are settled primarily with treasury shares.
	Employee stock options are granted to purchase shares of Company stock at the fair market value at the time of grant. These awards generally vest one-third each year over a three-year period, with a contractual term of 7-10 years. RSUs are stock awards that are granted to employees and entitle the holder to shares of common stock as the awards vest. The fair value of the stock option and RSU awards is determined and fixed on the grant date based on the Company’s stock price. PSUs are stock awards where the ultimate number of shares issued will be contingent on the Company’s performance against a pre-set objective or set of objectives. The fair value of each PSU is determined on the date of grant based on the Company’s stock price. For RSUs and certain PSUs granted before December 31, 2009 employees participate in dividends on the same basis as common shares and such dividends are nonforfeitable by the holder. For RSUs and PSUs issued on or after January 1, 2010, dividends declared during the vesting period are payable to the employees only upon vesting. Over the PSU performance period, the number of shares of stock that are expected to be issued will be adjusted based on the probability of achievement of a performance target and final compensation expense will be recognized based on the ultimate number of shares issued. RSU and PSU distributions will be in shares of Company stock after the end of the vesting or performance period, generally three years, subject to the terms applicable to such awards.
	Total pretax share-based compensation cost recorded in 2014, 2013 and 2012 was $278 million, $276 million and $335 million, respectively, with related income tax benefits of $86 million, $84 million and $105 million, respectively.
	The Company uses the Black-Scholes option pricing model for determining the fair value of option grants. In applying this model, the Company uses both historical data and current market data to estimate the fair value of its options. The Black-Scholes model requires several assumptions including expected dividend yield, risk-free interest rate, volatility, and term of the options. The expected dividend yield is based on historical patterns of dividend payments. The risk-free rate is based on the rate at grant date of zero-coupon U.S. Treasury Notes with a term equal to the expected term of the option. Expected volatility is estimated using a blend of historical and implied volatility. The historical component is based on historical monthly price changes. The implied volatility is obtained from market data on the Company’s traded options. The expected life represents the amount of time that options granted are expected to be outstanding, based on historical and forecasted exercise behavior.
	The weighted average exercise price of options granted in 2014, 2013 and 2012 was $58.14, $45.01 and $39.51 per option, respectively. The weighted average fair value of options granted in 2014, 2013 and 2012 was $6.79, $6.21 and $5.47 per option, respectively, and were determined using the following assumptions:


	Years Ended December 31	2014			2013			2012
	Expected dividend yield	4.3	%		4.2	%		4.4	%
	Risk-free interest rate	2	%		1.2	%		1.3	%
	Expected volatility	22	%		25	%		25.2	%
	Expected life (years)	6.4			7			7

	Summarized information relative to stock option plan activity (options in thousands) is as follows:


		Number			Weighted				Weighted		Aggregate
		of Options			Average				Average		Intrinsic
					Exercise				Remaining		Value
					Price				Contractual
									Term (Years)
	Outstanding January 1, 2014	115,805			$	38.75

	Granted	4,872			58.14

	Exercised	(39,293	)		39.71

	Forfeited	(5,249	)		45.28

	Outstanding December 31, 2014	76,135			$	39.05			3.85		$	1,358

	Exercisable December 31, 2014	65,324			$	37.56			3.21		$	1,257

	Additional information pertaining to stock option plans is provided in the table below:


	Years Ended December 31	2014				2013				2012
	Total intrinsic value of stock options exercised	$	626			$	374			$	528

	Fair value of stock options vested	35				42				80

	Cash received from the exercise of stock options	1,560				1,210				1,310

	A summary of nonvested RSU and PSU activity (shares in thousands) is as follows:


			RSUs							PSUs
			Number			Weighted				Number			Weighted
			of Shares			Average				of Shares			Average
						Grant Date							Grant Date
						Fair Value							Fair Value
	Nonvested January 1, 2014		19,134			$	40.07			1,673			$	35.98

	Granted		4,776			58.13				1,224			62.94

	Vested		(6,866	)		36.36				(723	)		33.97

	Forfeited		(1,410	)		46.22				(292	)		45.49

	Nonvested December 31, 2014		15,634			$	46.66			1,882			$	52.81

	At December 31, 2014, there was $401 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 1.9 years. For segment reporting, share-based compensation costs are unallocated expenses.

Pension_and_Other_Postretireme

Pension and Other Postretirement Benefit Plans	12 Months Ended
	Dec. 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. As a result of plan design changes approved in 2011, beginning on January 1, 2013, active participants in Merck’s primary U.S. defined benefit pension plans are accruing pension benefits using new cash balance formulas based on age, service, pay and interest. However, during a transition period from January 1, 2013 through December 31, 2019, participants will earn the greater of the benefit as calculated under the employee’s legacy final average pay formula or their new cash balance formula. For all years of service after December 31, 2019, participants will earn future benefits under only the cash balance formula. In addition, the Company provides medical benefits, principally to its eligible U.S. retirees and their dependents, through its other postretirement benefit plans. The Company uses December 31 as the year-end measurement date for all of its pension plans and other postretirement benefit plans.

	Net Periodic Benefit Cost
	The net periodic benefit cost for pension and other postretirement benefit plans consisted of the following components:


		Pension Benefits
		U.S.												International												Other Postretirement Benefits
	Years Ended December 31	2014				2013				2012				2014				2013				2012				2014				2013				2012
	Service cost	$	300			$	386			$	324			$	266			$	296			$	231			$	78			$	102			$	82

	Interest cost	425				402				401				269				263				260				115				107				121

	Expected return on plan assets	(782		)		(721		)		(617		)		(416		)		(376		)		(354		)		(139		)		(126		)		(136		)
	Net amortization	74				251				149				59				85				36				(71		)		(50		)		(35		)

	Termination benefits	53				51				17				11				7				10				22				50				18

	Curtailments	(69		)		(22		)		(11		)		(4		)		(1		)		2				(39		)		(11		)		(7		)

	Settlements	11				1				5				6				22				13				—				—				—

	Net periodic benefit cost (credit)	$	12			$	348			$	268			$	191			$	296			$	198			$	(34	)		$	72			$	43

	The decrease in net periodic benefit cost for pension and other postretirement benefit plans in 2014 as compared with 2013 is largely attributable to a change in the discount rate.
	In connection with restructuring actions (see Note 3), termination charges were recorded in 2014, 2013 and 2012 on pension and other postretirement benefit plans related to expanded eligibility for certain employees exiting Merck. Also, in connection with these restructuring activities, curtailments were recorded in 2014, 2013 and 2012 on pension and other postretirement benefit plans.
	In addition, settlements were recorded in 2014, 2013 and 2012 on certain U.S. and international pension plans.

	Obligations and Funded Status
	Summarized information about the changes in plan assets and benefit obligations, the funded status and the amounts recorded at December 31 is as follows:


		Pension Benefits																Other
																		Postretirement
		U.S.								International								Benefits
		2014				2013				2014				2013				2014				2013
	Fair value of plan assets January 1	$	10,007			$	8,683			$	7,428			$	6,666			$	1,913			$	1,760

	Actual return on plan assets	484				1,821				1,099				703				114				199

	Company contributions	92				54				276				591				67				73

	Effects of exchange rate changes	—				—				(816		)		(84		)		—				—

	Benefits paid	(535		)		(542		)		(245		)		(238		)		(110		)		(119		)
	Settlements	(64		)		(9		)		(31		)		(227		)		—				—

	Other	—				—				13				17				—				—

	Fair value of plan assets December 31	$	9,984			$	10,007			$	7,724			$	7,428			$	1,984			$	1,913

	Benefit obligation January 1	8,666				9,961				7,389				7,685				2,329				2,650

	Service cost	300				386				266				296				78				102

	Interest cost	425				402				269				263				115				107

	Actuarial losses (gains)	1,857				(1,565		)		1,605				(124		)		212				(428		)

	Benefits paid	(535		)		(542		)		(245		)		(238		)		(110		)		(119		)
	Effects of exchange rate changes	—				—				(864		)		(21		)		(6		)		(5		)

	Plan amendments	—				1				(4		)		(226		)		—				(38		)

Curtailments	(70		)		(19		)		(76		)		(42		)		3				—

Termination benefits	53				51				11				7				22				50

Settlements	(64		)		(9		)		(31		)		(227		)		—				—

Other	—				—				11				16				(5		)		10

Benefit obligation December 31	$	10,632			$	8,666			$	8,331			$	7,389			$	2,638			$	2,329

Funded status December 31	$	(648	)		$	1,341			$	(607	)		$	39			$	(654	)		$	(416	)

Recognized as:
Other assets	$	68			$	2,106			$	565			$	705			$	1			$	—

Accrued and other current liabilities	(41		)		(44		)		(11		)		(9		)		(11		)		(8		)
Other noncurrent liabilities	(675		)		(721		)		(1,161		)		(657		)		(644		)		(408		)
At December 31, 2014 and 2013, the accumulated benefit obligation was $17.9 billion and $14.8 billion, respectively, for all pension plans, of which $10.1 billion and $8.0 billion, respectively, related to U.S. pension plans.
Actuarial losses in 2014 reflect a change in the discount rate and, for U.S. plans, also reflect an impact for the Company’s adoption of new retirement plan mortality assumptions issued by the Society of Actuaries in October 2014.
Information related to the funded status of selected pension plans at December 31 is as follows:


	U.S.								International
	2014				2013				2014				2013
Pension plans with a projected benefit obligation in excess of plan assets
Projected benefit obligation	$	3,963			$	764			$	5,513			$	2,196

Fair value of plan assets	3,247				—				4,341				1,529

Pension plans with an accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	$	810			$	619			$	2,749			$	1,871

Fair value of plan assets	138				—				1,870				1,424


Plan Assets
Entities are required to use 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. The 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. At December 31, 2014 and 2013, $580 million and $622 million, respectively, or approximately 3% and 4%, respectively, of the Company’s pension investments at each year end, were categorized as Level 3 assets.
If the inputs used to measure the financial assets 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.
The fair values of the Company’s pension plan assets at December 31 by asset category are as follows:


	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)
	2014																2013
U.S. Pension Plans
Assets
Cash and cash equivalents	$	2			$	234			$	—			$	236			$	(54	)		$	223			$	—			$	169

Investment funds
Developed markets equities	540				4,518				—				5,058				581				4,772				—				5,353

Emerging markets equities	107				718				—				825				100				734				—				834

Government and agency obligations	—				31				—				31				—				29				—				29

Fixed income obligations	—				132				—				132				—				125				—				125

Equity securities
Developed markets	2,169				—				—				2,169				2,138				—				—				2,138

Fixed income securities
Government and agency obligations	—				516				—				516				—				444				—				444

Corporate obligations	—				722				—				722				—				590				—				590

Mortgage and asset-backed securities	—				245				—				245				—				245				—				245

Other investments
Derivatives	1				31				—				32				1				—				—				1

Other	—				—				28				28				—				48				31				79

Liabilities
Derivatives	—				10				—				10				—				—				—				—

	$	2,819			$	7,137			$	28			$	9,984			$	2,766			$	7,210			$	31			$	10,007

International Pension Plans
Assets
Cash and cash equivalents	$	208			$	13			$	—			$	221			$	142			$	24			$	—			$	166

Investment funds

Developed markets equities	217				2,991				—				3,208				227				2,872				—				3,099

Emerging markets equities	31				256				—				287				63				302				—				365

Government and agency obligations	317				1,410				—				1,727				293				1,151				—				1,444

Corporate obligations	183				170				—				353				188				77				—				265

Fixed income obligations	9				16				—				25				17				20				—				37

Real estate (1)	—				8				29				37				4				57				49				110

Equity securities

Developed markets	509				—				—				509				407				—				—				407

Fixed income securities

Government and agency obligations	28				448				—				476				2				652				—				654

Corporate obligations	2				190				1				193				—				151				—				151

Mortgage and asset-backed securities	—				90				—				90				—				54				—				54

Other investments

Insurance contracts (2)	—				69				521				590				—				128				540				668

Other	3				4				1				8				—				6				2				8

	$	1,507			$	5,665			$	552			$	7,724			$	1,343			$	5,494			$	591			$	7,428


(1)	The plans’ Level 3 investments in real estate funds are generally valued by market appraisals of the underlying investments in the funds.

(2)	The plans’ Level 3 investments in insurance contracts are generally valued using a crediting rate that approximates market returns and invest in underlying securities whose market values are unobservable and determined using pricing models, discounted cash flow methodologies, or similar techniques.
The table below provides a summary of the changes in fair value, including transfers in and/or out, of all financial assets measured at fair value using significant unobservable inputs (Level 3) for the Company’s pension plan assets:


	2014																2013
	Insurance				Real				Other				Total				Insurance				Real				Other				Total
	Contracts				Estate												Contracts				Estate
U.S. Pension Plans
Balance January 1	$	—			$	—			$	31			$	31			$	—			$	—			$	32			$	32

Actual return on plan assets:
Relating to assets still held at December 31	—				—				1				1				—				—				1				1

Relating to assets sold during the year	—				—				4				4				—				—				3				3

Purchases	—				—				1				1				—				—				2				2

Sales	—				—				(9		)		(9		)		—				—				(7		)		(7		)

Balance December 31	$	—			$	—			$	28			$	28			$	—			$	—			$	31			$	31

International Pension Plans
Balance January 1	$	540			$	49			$	2			$	591			$	496			$	141			$	23			$	660

Actual return on plan assets:
Relating to assets still held at December 31	(35		)		(4		)		—				(39		)		30				—				—				30

Relating to assets sold during the year	—				—				—				—				1				(1		)		—				—

Purchases	22				—				—				22				18				—				—				18

Sales	(3		)		(10		)		—				(13		)		(2		)		—				(21		)		(23		)

Transfers out of Level 3	(3		)		(6		)		—				(9		)		(3		)		(91		)		—				(94		)

Balance December 31	$	521			$	29			$	2			$	552			$	540			$	49			$	2			$	591

The fair values of the Company’s other postretirement benefit plan assets at December 31 by asset category are as follows:


	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)
	2014																2013
Assets
Cash and cash equivalents	$	60			$	20			$	—			$	80			$	47			$	20			$	—			$	67

Investment funds
Developed markets equities	51				613				—				664				54				667				—				721

Emerging markets equities	36				93				—				129				36				95				—				131

Government and agency obligations	3				2				—				5				—				—				—				—

Fixed income obligations	—				12				—				12				3				14				—				17

Equity securities
Developed markets	204				—				—				204				199				—				—				199

Fixed income securities
Government and agency obligations	—				333				—				333				—				257				—				257

Corporate obligations	—				336				—				336				—				281				—				281

Mortgage and asset-backed securities	—				219				—				219				—				219				—				219

Other fixed income obligations	—				—				—				—				—				21				—				21

Other investments
Derivatives	—				2				—				2				—				—				—				—

	$	354			$	1,630			$	—			$	1,984			$	339			$	1,574			$	—			$	1,913

The Company has established investment guidelines for its U.S. pension and other postretirement plans to create an asset allocation that is expected to deliver a rate of return sufficient to meet the long-term obligation of each plan, given an acceptable level of risk. The target investment portfolio of the Company’s U.S. pension and other postretirement benefit plans is allocated 40% to 60% in U.S. equities, 20% to 40% in international equities, 15% to 25% in fixed-income investments, and up to 5% in cash and other investments. The portfolio’s equity weighting is consistent with the long-term nature of the plans’ benefit obligations. The expected annual standard deviation of returns of the target portfolio, which approximates 13%, reflects both the equity allocation and the diversification benefits among the asset classes in which the portfolio invests. For international pension plans, the targeted investment portfolio varies based on the duration of pension liabilities and local government rules and regulations. Although a significant percentage of plan assets are invested in U.S. equities, concentration risk is mitigated through the use of strategies that are diversified within management guidelines.

Expected Contributions
Expected contributions during 2015 are approximately $40 million for U.S. pension plans, approximately $150 million for international pension plans and approximately $65 million for other postretirement benefit plans.

Expected Benefit Payments
Expected benefit payments are as follows:


	U.S. Pension Benefits				International Pension				Other
					Benefits				Postretirement
									Benefits
2015	$	469			$	213			$	109

2016	495				185				117

2017	491				192				124

2018	525				206				131

2019	549				215				138

2020 — 2024	3,238				1,323				792

Expected benefit payments are based on the same assumptions used to measure the benefit obligations and include estimated future employee service.

Amounts Recognized in Other Comprehensive Income
Net loss amounts reflect experience differentials primarily relating to differences between expected and actual returns on plan assets as well as the effects of changes in actuarial assumptions. Net loss amounts in excess of certain thresholds are amortized into net pension and other postretirement benefit cost over the average remaining service life of employees. The following amounts were reflected as components of OCI:


	Pension Plans																								Other Postretirement
	U.S.												International												Benefit Plans
Years Ended December 31	2014				2013				2012				2014				2013				2012				2014				2013				2012
Net (loss) gain arising during the period	$	(2,085	)		$	2,676			$	(688	)		$	(779	)		$	513			$	(1,219	)		$	(223	)		$	499			$	(24	)

Prior service (cost) credit arising during the period	(59		)		(23		)		(16		)		(8		)		226				3				(42		)		26				78

	$	(2,144	)		$	2,653			$	(704	)		$	(787	)		$	739			$	(1,216	)		$	(265	)		$	525			$	54

Net loss amortization included in benefit cost	$	135			$	318			$	217			$	74			$	89			$	39			$	1			$	23			$	31

Prior service (credit) cost amortization included in benefit cost	(61		)		(67		)		(68		)		(15		)		(4		)		(3		)		(72		)		(73		)		(66		)
	$	74			$	251			$	149			$	59			$	85			$	36			$	(71	)		$	(50	)		$	(35	)

The estimated net loss (gain) and prior service cost (credit) amounts that will be amortized from AOCI into net pension and postretirement benefit cost during 2015 are $353 million and $(72) million, respectively, for pension plans (of which $227 million and $(57) million, respectively, relates to U.S. pension plans) and are $4 million and $(65) million, respectively, for other postretirement benefit plans.

Actuarial Assumptions
The Company reassesses its benefit plan assumptions on a regular basis. The weighted average assumptions used in determining U.S. pension and other postretirement benefit plan and international pension plan information are as follows:


	U.S. Pension and Other									International Pension Plans
	Postretirement Benefit Plans
December 31	2014			2013			2012			2014			2013			2012

Net periodic benefit cost
Discount rate	4.9	%		4.1	%		4.8	%		3.8	%		3.6	%		4.6	%
Expected rate of return on plan assets	8.5	%		8.5	%		8.7	%		6	%		5.8	%		5.9	%
Salary growth rate	4.5	%		4.5	%		4.5	%		3.1	%		3.3	%		3.4	%
Benefit obligation
Discount rate	4.2	%		5.1	%		4.1	%		2.7	%		3.8	%		3.6	%
Salary growth rate	4.4	%		4.5	%		4.5	%		2.9	%		3.1	%		3.3	%
For both the pension and other postretirement benefit plans, the discount rate is evaluated on measurement dates and modified to reflect the prevailing market rate of a portfolio of high-quality fixed-income debt instruments that would provide the future cash flows needed to pay the benefits included in the benefit obligation as they come due. The expected rate of return for both the pension and other postretirement benefit plans represents the average rate of return to be earned on plan assets over the period the benefits included in the benefit obligation are to be paid and is determined on a plan basis. In developing the expected rate of return within each plan, long-term historical returns data are considered as well as actual returns on the plan assets and other capital markets experience. Using this reference information, the long-term return expectations for each asset category and a weighted average expected return for each plan’s target portfolio is developed, according to the allocation among those investment categories. The expected portfolio performance reflects the contribution of active management as appropriate. For 2015, the Company’s expected rate of return will range from 7.30% to 8.75%, the same range as in 2014 for its U.S. pension and other postretirement benefit plans.
The health care cost trend rate assumptions for other postretirement benefit plans are as follows:


December 31	2014			2013
Health care cost trend rate assumed for next year	6.9	%		7.1	%
Rate to which the cost trend rate is assumed to decline	4.6	%		4.6	%
Year that the trend rate reaches the ultimate trend rate	2027			2027

A one percentage point change in the health care cost trend rate would have had the following effects:


	One Percentage Point
	Increase				Decrease
Effect on total service and interest cost components	$	32			$	(27	)

Effect on benefit obligation	421				(339		)


Savings Plans
The Company also maintains defined contribution savings plans in the United States. The Company matches a percentage of each employee’s contributions consistent with the provisions of the plan for which the employee is eligible. Total employer contributions to these plans in 2014, 2013 and 2012 were $124 million, $138 million and $146 million, respectively.

Other_Income_Expense_Net

Other (Income) Expense, Net	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Other (Income) Expense, Net	Other (Income) Expense, Net
	Other (income) expense, net, consisted of:


	Years Ended December 31	2014			2013			2012
	Interest income	$	(266	)	$	(264	)	$	(232	)
	Interest expense	732			801			714

	Exchange losses	180			290			185

	Other, net	(12,002		)	(12		)	449

		$	(11,356	)	$	815		$	1,116

	Exchange losses in 2013 reflect $140 million of losses due 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 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 (as presented in the table above) in 2014 includes an $11.2 billion gain on the divestiture of MCC, a gain of $741 million related to AstraZeneca’s option exercise, a $480 million gain on the divestiture of certain ophthalmic products in several international markets and a gain of $204 million related to the divestiture of Sirna, partially offset by a $628 million loss on extinguishment of debt and a $93 million goodwill impairment charge related to the Company’s joint venture with Supera (see Notes 4, 8 and 9 for additional information related to these transactions). Other, net in 2012 reflects a $493 million net charge related to the previously disclosed settlement of the ENHANCE Litigation.
	Interest paid was $852 million in 2014, $922 million in 2013 and $808 million in 2012.

Taxes_on_Income

Taxes on Income	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Taxes on Income	Taxes on Income
	A reconciliation between the effective tax rate and the U.S. statutory rate is as follows:


		2014							2013						2012
		Amount				Tax Rate			Amount				Tax Rate		Amount			Tax Rate
	U.S. statutory rate applied to income before taxes	$	6,049			35	%		$	1,941			35	%	$	3,059		35	%

	Differential arising from:
	Foreign earnings	(1,486		)		(8.6	)		(1,316		)		(23.7	)	(1,955		)	(22.4	)
	AstraZeneca option exercise	(774		)		(4.5	)		—				—		—			—

	Sale of Sirna Therapeutics, Inc.	(357		)		(2.1	)		—				—		—			—

	Tax settlements	(89		)		(0.5	)		(497		)		(9.0	)	(113		)	(1.3	)
	The American Taxpayer Relief Act of 2012	—				—			(269		)		(4.8	)	—			—

	Unremitted foreign earnings	(209		)		(1.2	)		(81		)		(1.5	)	(11		)	(0.1	)
	Amortization of purchase accounting adjustments	865				5			934				16.8		905			10.3

	Divestiture of Merck Consumer Care	440				2.5			—				—		—			—

	Restructuring	289				1.7			224				4		62			0.7

	U.S. health care reform legislation	134				0.8			65				1.2		60			0.7

	Intangible asset impairment charges	148				0.9			56				1		40			0.5

	Vioxx and ENHANCE litigation settlements	—				—			—				—		98			1.2

	State taxes	7				—			44				0.8		31			0.3

	Other (1)	332				1.9			(73		)		(1.3	)	264			3

		$	5,349			30.9	%		$	1,028			18.5	%	$	2,440		27.9	%


	(1)	Other includes the tax effect of contingency reserves, research credits, tax rate changes and miscellaneous items.
	The foreign earnings tax rate differentials in the tax rate reconciliation above primarily reflect the impacts of operations in jurisdictions with different tax rates than the United States, particularly Ireland and Switzerland, as well as Singapore and Puerto Rico which operate under tax incentive grants, where the earnings have been indefinitely reinvested, thereby yielding a favorable impact on the effective tax rate as compared with the 35.0% U.S. statutory rate. The foreign earnings tax rate differentials do not include the impact of intangible asset impairment charges, amortization of purchase accounting adjustments or restructuring costs. These items are presented separately as they each represent a significant, separately disclosed pretax cost or charge, and a substantial portion of each of these items relates to jurisdictions with lower tax rates than the United States. Therefore, the impact of recording these expense items in lower tax rate jurisdictions is an unfavorable impact on the effective tax rate as compared to the 35.0% U.S. statutory rate.
	The Company’s 2014 effective tax rate reflects the impact of the Tax Increase Prevention Act, that was signed into law on December 19, 2014, extending the research credit and the controlled foreign corporation look-through provisions. The American Taxpayer Relief Act of 2012 was signed into law on January 2, 2013, extending the research credit and the controlled foreign corporation look-through provisions for two years retroactively from January 1, 2012 through December 31, 2013. The Company recorded the entire 2012 benefit of $269 million in 2013, the financial statement period that included the date of enactment.
	Income before taxes consisted of:


	Years Ended December 31	2014				2013				2012
	Domestic	$	15,730			$	3,513			$	4,500

	Foreign	1,553				2,032				4,239

		$	17,283			$	5,545			$	8,739

	Taxes on income consisted of:


	Years Ended December 31	2014				2013				2012
	Current provision
	Federal	$	7,136			$	568			$	1,346

	Foreign	438				923				651

	State	375				(133		)		(226		)

		7,949				1,358				1,771

	Deferred provision
Federal	(2,162		)		30				749

Foreign	(201		)		(398		)		(323		)
State	(237		)		38				243

	(2,600		)		(330		)		669

	$	5,349			$	1,028			$	2,440

Deferred income taxes at December 31 consisted of:


	2014								2013
	Assets				Liabilities				Assets				Liabilities
Intangibles	$	—			$	3,358			$	—			$	3,772

Inventory related	56				699				49				604

Accelerated depreciation	58				892				125				1,215

Unremitted foreign earnings	—				2,016				—				2,361

Equity investments	5				—				—				539

Pensions and other postretirement benefits	778				156				162				543

Compensation related	578				—				600				—

Unrecognized tax benefits	401				—				497				—

Net operating losses and other tax credit carryforwards	379				—				225				—

Other	1,530				65				1,605				71

Subtotal	3,785				7,186				3,263				9,105

Valuation allowance	(265		)						(205		)
Total deferred taxes	$	3,520			$	7,186			$	3,058			$	9,105

Net deferred income taxes					$	3,666							$	6,047

Recognized as:
Deferred income taxes and other current assets	$	568							$	572

Other assets	401								381

Income taxes payable					$	369							$	224

Deferred income taxes					4,266								6,776

The Company has net operating loss (“NOL”) carryforwards in several jurisdictions. As of December 31, 2014, $203 million of deferred taxes on NOL carryforwards relate to foreign jurisdictions, none of which are individually significant. Valuation allowances of $265 million have been established on these foreign NOL carryforwards and other foreign deferred tax assets. In addition, the Company has approximately $175 million of deferred tax assets relating to various U.S. tax credit carryforwards and NOL carryforwards, all of which are expected to be fully utilized prior to expiry.
Income taxes paid in 2014, 2013 and 2012 were $7.9 billion, $2.3 billion and $2.5 billion, respectively. Income taxes paid in 2014 reflects approximately $5.0 billion of taxes paid on the divestiture of MCC. Tax benefits relating to stock option exercises were $202 million in 2014, $70 million in 2013 and $81 million in 2012.
A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:


	2014				2013				2012
Balance January 1	$	3,503			$	4,425			$	4,277

Additions related to current year positions	389				320				496

Additions related to prior year positions	23				177				58

Reductions for tax positions of prior years (1)	(156		)		(747		)		(320		)
Settlements	(161		)		(603		)		(67		)
Lapse of statute of limitations	(64		)		(69		)		(19		)
Balance December 31	$	3,534			$	3,503			$	4,425


(1)	Amounts reflect the settlements with the IRS and CRA as discussed below.
If the Company were to recognize the unrecognized tax benefits of $3.5 billion at December 31, 2014, the income tax provision would reflect a favorable net impact of $3.3 billion.
The Company is under examination by numerous tax authorities in various jurisdictions globally. The Company believes that it is reasonably possible that the total amount of unrecognized tax benefits as of December 31, 2014 could decrease by up to $1.3 billion in the next 12 months as a result of various audit closures, settlements or the expiration of the statute of limitations. The ultimate finalization of the Company’s examinations with relevant taxing authorities can include formal administrative and legal proceedings, which could have a significant impact on the timing of the reversal of unrecognized tax benefits. The Company believes that its reserves for uncertain tax positions are adequate to cover existing risks or exposures.
Interest and penalties associated with uncertain tax positions amounted to an expense of $9 million in 2014 and benefits of $319 million in 2013 and $88 million in 2012. These amounts reflect the beneficial impacts of various tax settlements, including those discussed below. Liabilities for accrued interest and penalties were $659 million and $665 million as of December 31, 2014 and 2013, respectively.
The Internal Revenue Service (the “IRS”) is currently conducting examinations of the Company’s tax returns for the years 2006 through 2008, as well as 2010 and 2011. Although concluded, one issue related to a refund claim of taxes paid remains from the examination of the Company’s 2002-2005 federal tax returns, which the Company is currently appealing through the IRS administrative appeals process.
In addition, various state and foreign tax examinations are in progress. For most of its other significant tax jurisdictions (both U.S. state and foreign), the Company’s income tax returns are open for examination for the period 2003 through 2014.
In 2013, IRS finalized its examination of Schering-Plough’s 2007-2009 tax years. The Company’s unrecognized tax benefits for the years under examination exceeded the adjustments related to this examination period and therefore the Company recorded a net $165 million tax provision benefit in 2013.
In 2010, 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 NOLs 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 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 year financial statements.
As previously disclosed, the Canada Revenue Agency (the “CRA”) had proposed adjustments for 1999 and 2000 relating to intercompany pricing matters and issued assessments for other miscellaneous audit issues for tax years 2001-2004. In 2012, Merck and the CRA reached a settlement for these years that calls for Merck to pay additional Canadian tax of approximately $65 million. The Company’s unrecognized tax benefits related to these matters exceeded the settlement amount and therefore the Company recorded a net $112 million tax provision benefit in 2012. A portion of the taxes paid is expected to be creditable for U.S. tax purposes. The Company had previously established reserves for these matters. The resolution of these matters did not have a material effect on the Company’s results of operations, financial position or liquidity.
At December 31, 2014, foreign earnings of $60.0 billion have been retained indefinitely by subsidiary companies for reinvestment; therefore, no provision has been made for income taxes that would be payable upon the distribution of such earnings and it would not be practicable to determine the amount of the related unrecognized deferred income tax liability. In addition, the Company has subsidiaries operating in Puerto Rico and Singapore under tax incentive grants that begin to expire in 2022.

Earnings_per_Share

Earnings per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Earnings per Share	Earnings per Share
	Prior to 2013, the Company calculated earnings per share pursuant to the two-class method under which all earnings (distributed and undistributed) are allocated to common shares and participating securities based on their respective rights to receive dividends. RSUs and certain PSUs granted before December 31, 2009 (which generally have a three year vesting period) to certain management level employees met the definition of participating securities. RSUs and PSUs issued on or after January 1, 2010, do not meet the definition of participating securities; therefore, beginning in 2013 the Company no longer applies the two-class method.
	The calculations of earnings per share are as follows:


	Years Ended December 31	2014		2013		2012
	Basic Earnings per Common Share
	Net income attributable to Merck & Co., Inc.	$	11,920	$	4,404	$	6,168

	Less: Income allocated to participating securities	—		—		3

	Net income allocated to common shareholders	$	11,920	$	4,404	$	6,165

	Average common shares outstanding	2,894		2,963		3,041

		$	4.12	$	1.49	$	2.03

	Earnings per Common Share Assuming Dilution
	Net income attributable to Merck & Co., Inc.	$	11,920	$	4,404	$	6,168

	Less: Income allocated to participating securities	—		—		3

	Net income allocated to common shareholders	$	11,920	$	4,404	$	6,165

	Average common shares outstanding	2,894		2,963		3,041

	Common shares issuable (1)	34		33		35

	Average common shares outstanding assuming dilution	2,928		2,996		3,076

		$	4.07	$	1.47	$	2


	(1)	Issuable primarily under share-based compensation plans.
	In 2014, 2013 and 2012, 4 million, 25 million and 104 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)	12 Months Ended
	Dec. 31, 2014
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss)
	Changes in AOCI by component are as follows:


		Derivatives				Investments				Employee				Cumulative			Accumulated Other
										Benefit				Translation			Comprehensive
										Plans				Adjustment			Income (Loss)
	Balance January 1, 2012, net of taxes	$	4			$	21			$	(2,346	)		$	(811	)	$	(3,132	)

	Other comprehensive income (loss) before reclassification adjustments, pretax	(198		)		74				(1,852		)		(99		)	(2,075		)

	Tax	77				(10		)		450				(81		)	436

	Other comprehensive income (loss) before reclassification adjustments, net of taxes	(121		)		64				(1,402		)		(180		)	(1,639		)

	Reclassification adjustments, pretax	33				(13		)		136				—			156

	Tax	(13		)		1				(55		)		—			(67		)

	Reclassification adjustments, net of taxes	20			(1)	(12		)	(2)	81			(3)	—			89

	Other comprehensive income (loss), net of taxes	(101		)		52				(1,321		)		(180		)	(1,550		)

	Balance December 31, 2012, net of taxes	(97		)		73				(3,667		)		(991		)	(4,682		)

	Other comprehensive income (loss) before reclassification adjustments, pretax	335				33				3,917				(383		)	3,902

	Tax	(132		)		(23		)		(1,365		)		(100		)	(1,620		)
	Other comprehensive income (loss) before reclassification adjustments, net of taxes	203				10				2,552				(483		)	2,282

	Reclassification adjustments, pretax	42				(39		)		286				—			289

	Tax	(16		)		10				(80		)		—			(86		)

	Reclassification adjustments, net of taxes	26			(1)	(29		)	(2)	206			(3)	—			203

	Other comprehensive income (loss), net of taxes	229				(19		)		2,758				(483		)	2,485

	Balance December 31, 2013, net of taxes	132				54				(909		)	(4)	(1,474		)	(2,197		)

	Other comprehensive income (loss) before reclassification adjustments, pretax	778				48				(3,196		)		(412		)	(2,782		)

	Tax	(285		)		(17		)		1,067				(92		)	673

	Other comprehensive income (loss) before reclassification adjustments, net of taxes	493				31				(2,129		)		(504		)	(2,109		)

	Reclassification adjustments, pretax	(146		)		43				62				—			(41		)

	Tax	51				(17		)		(10		)		—			24

	Reclassification adjustments, net of taxes	(95		)	(1)	26			(2)	52			(3)	—			(17		)

	Other comprehensive income (loss), net of taxes	398				57				(2,077		)		(504		)	(2,126		)

	Balance December 31, 2014, net of taxes	$	530			$	111			$	(2,986	)	(4)	$	(1,978	)	$	(4,323	)


	-1	Relates to foreign currency cash flow hedges that were reclassified from AOCI to Sales.

	(2)	Represents net realized (gains) losses 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 13).

	(4)	Includes pension plan net loss of $(3.5) billion and $(1.7) billion at December 31, 2014 and 2013, respectively, and other postretirement benefit plan net loss of $(228) million and $(80) million at December 31, 2014 and in 2013, respectively, as well as pension plan prior service credit of $473 million and $559 million at December 31, 2014 and 2013, respectively, and other postretirement benefit plan prior service credit of $257 million and $331 million at December 31, 2014 and 2013.

Segment_Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting
	The Company’s operations are principally managed on a products basis and are comprised of three operating segments – Pharmaceutical, Animal Health and Alliances (which includes revenue and equity income from the Company’s relationship with AZLP until the June 30, 2014 termination date). The Animal Health and Alliances segments are not material for separate reporting and are included in all other in the table below. 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. On October 1, 2014, the Company divested its Consumer Care segment (see Note 4) that developed, manufactured and marketed over-the-counter, foot care and sun care products.
	The accounting policies for the segments described above are the same as those described in Note 2.
	Sales of the Company’s products were as follows:


	Years Ended December 31	2014			2013			2012
	Primary Care and Women’s Health
	Cardiovascular
	Zetia	$	2,650		$	2,658		$	2,567

	Vytorin	1,516			1,643			1,747

	Diabetes
	Januvia	3,931			4,004			4,086

	Janumet	2,071			1,829			1,659

	General Medicine and Women’s Health
	NuvaRing	723			686			623

	Implanon/Nexplanon	502			403			348

	Dulera	460			324			207

	Follistim AQ	412			481			468

	Hospital and Specialty
	Hepatitis
	PegIntron	381			496			653

	Victrelis	153			428			502

	HIV
	Isentress	1,673			1,643			1,515

	Acute Care
	Cancidas	681			660			619

	Invanz	529			488			445

	Noxafil	402			309			258

	Bridion	340			288			261

	Primaxin	329			335			384

	Immunology
	Remicade	2,372			2,271			2,076

	Simponi	689			500			331

	Other
	Cosopt/Trusopt	257			416			444

	Oncology
	Emend	553			507			489

	Temodar	350			708			917

	Keytruda	55			—			—

	Diversified Brands
	Respiratory
Nasonex	1,099			1,335			1,268

Singulair	1,092			1,196			3,853

Clarinex	232			235			393

Other
Cozaar/Hyzaar	806			1,006			1,284

Arcoxia	519			484			453

Fosamax	470			560			676

Propecia	264			283			424

Zocor	258			301			383

Remeron	193			206			232

Vaccines *(1)*
Gardasil	1,738			1,831			1,631

ProQuad/M-M-R II/Varivax	1,394			1,306			1,273

Zostavax	765			758			651

Pneumovax 23	746			653			580

RotaTeq	659			636			601

Other pharmaceutical (2)	4,778			5,570			6,300

Total Pharmaceutical segment sales	36,042			37,437			40,601

Other segment sales (3)	5,585			6,325			6,412

Total segment sales	41,627			43,762			47,013

Other (4)	610			271			254

	$	42,237		$	44,033		$	47,267


(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 and Alliances, as well as Consumer Care until its divestiture on October 1, 2014 (see Note 4). The Alliances segment includes revenue from the Company’s relationship with AZLP until termination on June 30, 2014 (see Note 8).

(4)	Other revenues are primarily comprised of miscellaneous corporate revenues, including revenue hedging activities, sales related to divested products or businesses, and other supply sales not included in segment results. Other revenues in 2014 include $232 million received by Merck in connection with the sale of the U.S. marketing rights to Saphris (see Note 4). Other revenues in 2013 reflect $50 million of revenue for the out-license of a pipeline compound. Other revenues also include third-party manufacturing sales, a substantial portion of which was divested in October 2013 (see Note 3).
Consolidated revenues by geographic area where derived are as follows:


Years Ended December 31	2014			2013			2012
United States	$	17,071		$	18,246		$	20,392

Europe, Middle East and Africa	13,174			13,140			12,990

Asia Pacific	3,951			3,845			3,775

Japan	3,471			4,044			5,102

Latin America	3,151			3,203			3,389

Other	1,419			1,555			1,619

	$	42,237		$	44,033		$	47,267

A reconciliation of total segment profits to consolidated Income before taxes is as follows:


Years Ended December 31	2014			2013			2012
Segment profits:
Pharmaceutical segment	$	22,164		$	22,983		$	25,852

Other segments	2,546			3,094			3,163

Total segment profits	24,710			26,077			29,015

Other profits	539			19			26

Unallocated:
Interest income	266			264			232

Interest expense	(732		)	(801		)	(714		)
Equity income from affiliates	59			(159		)	102

Depreciation and amortization	(2,457		)	(2,250		)	(2,059		)
Research and development	(5,837		)	(6,381		)	(7,126		)
Amortization of purchase accounting adjustments	(4,182		)	(4,690		)	(4,872		)
Restructuring costs	(1,013		)	(1,709		)	(664		)
Gain on divestiture of Merck Consumer Care	11,209			—			—

Gain on AstraZeneca option exercise	741			—			—

Gain on the divestiture of certain ophthalmic products	480			—			—

Loss on extinguishment of debt	(628		)	—			—

Net charge related to settlement of ENHANCE Litigation	—			—			(493		)

Other unallocated, net	(5,872		)	(4,825		)	(4,708		)
	$	17,283		$	5,545		$	8,739

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 or businesses and other supply sales.
Other unallocated, net includes expenses from corporate and manufacturing cost centers, goodwill and product intangible asset impairment charges, gain or losses on sales of businesses and other miscellaneous income or expense items.
Equity income from affiliates and depreciation and amortization included in segment profits is as follows:


	Pharmaceutical			All Other			Total
Year Ended December 31, 2014
Included in segment profits:
Equity income from affiliates	$	90		$	108		$	198

Depreciation and amortization	(39		)	(13		)	(52		)
Year Ended December 31, 2013
Included in segment profits:
Equity income from affiliates	$	88		$	475		$	563

Depreciation and amortization	(27		)	(22		)	(49		)
Year Ended December 31, 2012
Included in segment profits:
Equity income from affiliates	$	36		$	504		$	540

Depreciation and amortization	(25		)	(20		)	(45		)
Property, plant and equipment, net by geographic area where located is as follows:


Years Ended December 31	2014			2013			2012
United States	$	8,727		$	10,076		$	10,687

Europe, Middle East and Africa	3,120			3,346			3,688

Asia Pacific	897			1,001			1,059

Latin America	207			242			250

Japan	172			211			243

Other	13			97			103

	$	13,136		$	14,973		$	16,030

The Company does not disaggregate assets on a products and services basis for internal management reporting and, therefore, such information is not presented.

Summary_of_Accounting_Policies1

Summary of Accounting Policies Summary of Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation — The consolidated financial statements include the accounts of the Company and all of its subsidiaries in which a controlling interest is maintained. Intercompany balances and transactions are eliminated. Controlling interest is determined by majority ownership interest and the absence of substantive third-party participating rights or, in the case of variable interest entities, by majority exposure to expected losses, residual returns or both. For those consolidated subsidiaries where Merck ownership is less than 100%, the outside shareholders’ interests are shown as Noncontrolling interests in equity. Investments in affiliates over which the Company has significant influence but not a controlling interest, such as interests in entities owned equally by the Company and a third party that are under shared control, are carried on the equity basis.
Mergers and Acquisitions	Mergers and Acquisitions — In a business combination, the acquisition method of accounting requires that the assets acquired and liabilities assumed be recorded as of the date of the merger or acquisition at their respective fair values with limited exceptions. Assets acquired and liabilities assumed in a business combination that arise from contingencies are recognized at fair value if fair value can reasonably be estimated. If the acquisition date fair value of an asset acquired or liability assumed that arises from a contingency cannot be determined, the asset or liability is recognized if probable and reasonably estimable; if these criteria are not met, no asset or liability is recognized. 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. Accordingly, the Company may be required to value assets at fair value measures that do not reflect the Company’s intended use of those assets. Any excess of the purchase price (consideration transferred) over the estimated fair values of net assets acquired is recorded as goodwill. Transaction costs and costs to restructure the acquired company are expensed as incurred. The operating results of the acquired business are reflected in the Company’s consolidated financial statements after the date of the merger or acquisition. If the Company determines the assets acquired do not meet the definition of a business under the acquisition method of accounting, the transaction will be accounted for as an acquisition of assets rather than a business combination and, therefore, no goodwill will be recorded.
Foreign Currency Translation	Foreign Currency Translation — The net assets of international subsidiaries where the local currencies have been determined to be the functional currencies are translated into U.S. dollars using current exchange rates. The U.S. dollar effects that arise from translating the net assets of these subsidiaries at changing rates are recorded in the foreign currency translation account, which is included in Accumulated other comprehensive income (loss) (“AOCI”) and reflected as a separate component of equity. For those subsidiaries that operate in highly inflationary economies and for those subsidiaries where the U.S. dollar has been determined to be the functional currency, non-monetary foreign currency assets and liabilities are translated using historical rates, while monetary assets and liabilities are translated at current rates, with the U.S. dollar effects of rate changes included in Other (income) expense, net.
Cash Equivalents	Cash Equivalents — Cash equivalents are comprised of certain highly liquid investments with original maturities of less than three months.
Inventories	Inventories — Inventories are valued at the lower of cost or market. The cost of a substantial majority of domestic pharmaceutical and vaccine inventories is determined using the last-in, first-out (“LIFO”) method for both financial reporting and tax purposes. The cost of all other inventories is determined using the first-in, first-out (“FIFO”) method. Inventories consist of currently marketed products, as well as certain inventories produced in preparation for product launches that are considered to have a high probability of regulatory approval. In evaluating the recoverability of inventories produced in preparation for product launches, the Company considers the likelihood that revenue will be obtained from the future sale of the related inventory together with the status of the product within the regulatory approval process.
Investments	Investments — Investments in marketable debt and equity securities classified as available-for-sale are reported at fair value. Fair values of the Company’s investments are determined using quoted market prices in active markets for identical assets or liabilities or 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. Changes in fair value that are considered temporary are reported net of tax in Other Comprehensive Income (“OCI”). For declines in the fair value of equity securities that are considered other-than-temporary, impairment losses are charged to Other (income) expense, net. The Company considers available evidence in evaluating potential impairments of its investments, including the duration and extent to which fair value is less than cost and, for equity securities, the Company’s ability and intent to hold the investments. For debt securities, an other-than-temporary impairment has occurred if the Company does not expect to recover the entire amortized cost basis of the debt security. If the Company does not intend to sell the impaired debt security, and it is not more likely than not it will be required to sell the debt security before the recovery of its amortized cost basis, the amount of the other-than-temporary impairment recognized in earnings, recorded in Other (income) expense, net, is limited to the portion attributed to credit loss. The remaining portion of the other-than-temporary impairment related to other factors is recognized in OCI. Realized gains and losses for both debt and equity securities are included in Other (income) expense, net.
Revenue Recognition	Revenue Recognition — Revenues from sales of products are recognized when title and risk of loss passes to the customer, typically upon delivery. Recognition of revenue also requires reasonable assurance of collection of sales proceeds and completion of all performance obligations. Domestically, sales discounts are issued to customers as direct discounts at the point-of-sale, indirectly through an intermediary wholesaler, known as chargebacks, or indirectly in the form of rebates. Additionally, sales are generally made with a limited right of return under certain conditions. Revenues are recorded net of provisions for sales discounts and returns, which are established at the time of sale. In addition, revenues are recorded net of time value of money discounts if collection of accounts receivable is expected to be in excess of one year. Accruals for chargebacks are reflected as a direct reduction to accounts receivable and accruals for rebates are recorded as current liabilities. The accrued balances relative to the provisions for chargebacks and rebates included in Accounts receivable and Accrued and other current liabilities were $112 million and $2.0 billion, respectively, at December 31, 2014 and $87 million and $1.6 billion, respectively, at December 31, 2013.
Revenue Recognition	The Company recognizes revenue from the sales of vaccines to the Federal government for placement into vaccine stockpiles in accordance with Securities and Exchange Commission (“SEC”) Interpretation, Commission Guidance Regarding Accounting for Sales of Vaccines and BioTerror Countermeasures to the Federal Government for Placement into the Pediatric Vaccine Stockpile or the Strategic National Stockpile.
Depreciation	Depreciation — Depreciation is provided over the estimated useful lives of the assets, principally using the straight-line method. For tax purposes, accelerated tax methods are used. The estimated useful lives primarily range from 10 to 50 years for Buildings, and from 3 to 15 years for Machinery, equipment and office furnishings.
Advertising and Promotion Costs	Advertising and Promotion Costs — Advertising and promotion costs are expensed as incurred.
Software Capitalization	Software Capitalization — The Company capitalizes certain costs incurred in connection with obtaining or developing internal-use software including external direct costs of material and services, and payroll costs for employees directly involved with the software development. Capitalized software costs are included in Property, plant and equipment and amortized beginning when the software project is substantially complete and the asset is ready for its intended use. Capitalized software costs associated with projects that are being amortized over 6 to 10 years (including the Company’s on-going multi-year implementation of an enterprise-wide resource planning system) were $505 million and $548 million, net of accumulated amortization at December 31, 2014 and 2013, respectively. All other capitalized software costs are being amortized over periods ranging from 3 to 5 years. Costs incurred during the preliminary project stage and post-implementation stage, as well as maintenance and training costs, are expensed as incurred.
Goodwill	Goodwill — Goodwill represents the excess of the consideration transferred over the fair value of net assets of businesses purchased. Goodwill is assigned to reporting units and evaluated for impairment on at least an annual basis, or more frequently if impairment indicators exist, by first assessing qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If the Company concludes it is more likely than not that the fair value of a reporting unit is less than its carrying amount, a quantitative fair value test is performed.
Acquired Intangibles	Acquired Intangibles — Acquired intangibles include products and product rights, tradenames and patents, which are recorded at fair value, assigned an estimated useful life, and are amortized primarily on a straight-line basis over their estimated useful lives ranging from 3 to 20 years (see Note 7). The Company periodically evaluates whether current facts or circumstances indicate that the carrying values of its acquired intangibles may not be recoverable. If such circumstances are determined to exist, an estimate of the undiscounted future cash flows of these assets, or appropriate asset groupings, is compared to the carrying value to determine whether an impairment exists. If the asset is determined to be impaired, the loss is measured based on the difference between the carrying value of the intangible asset and its fair value, which is determined based on the net present value of estimated future cash flows.
Acquired In-Process Research and Development	Acquired In-Process Research and Development — Acquired in-process research and development (“IPR&D”) that the Company acquires through business combinations represents the fair value assigned to incomplete research projects which, at the time of acquisition, have not reached technological feasibility. The amounts are capitalized and are accounted for as indefinite-lived intangible assets, subject to impairment testing until completion or abandonment of the projects. Upon successful completion of each project, Merck will make a determination as to the then useful life of the intangible asset, generally determined by the period in which the substantial majority of the cash flows are expected to be generated, and begin amortization. The Company tests IPR&D for impairment at least annually, or more frequently if impairment indicators exist, by first assessing qualitative factors to determine whether it is more likely than not that the fair value of the IPR&D intangible asset is less than its carrying amount. If the Company concludes it is more likely than not that the fair value is less than the carrying amount, a quantitative test that compares the fair value of the IPR&D intangible asset with its carrying value is performed. If the fair value is less than the carrying amount, an impairment loss is recognized in operating results.
Contingent Consideration	Contingent Consideration — Certain of the Company’s business acquisitions involve the potential for future payment of consideration that is contingent upon the achievement of performance milestones, including product development milestones and royalty payments on future product sales. The fair value of contingent consideration liabilities is determined at the acquisition date using unobservable inputs. These inputs include the estimated amount and timing of projected cash flows, the probability of success (achievement of the contingent event) and the risk-adjusted discount rate used to present value the probability-weighted cash flows. Subsequent to the acquisition date, at each reporting period, the contingent consideration liability is remeasured at current fair value with changes recorded in earnings. Changes in any of the inputs may result in a significantly different fair value adjustment.
Research and Development	Research and Development — Research and development is expensed as incurred. Upfront and milestone payments due to third parties in connection with research and development collaborations prior to regulatory approval are expensed as incurred. Payments due to third parties upon or subsequent to regulatory approval are capitalized and amortized over the shorter of the remaining license or product patent life. Amounts due from collaborative partners related to development activities are generally reflected as a reduction of research and development expenses when the specific milestone has been achieved. Nonrefundable advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. Research and development expenses include restructuring costs and IPR&D impairment charges in all periods.
Share-based Compensation	Share-Based Compensation — The Company expenses all share-based payments to employees over the requisite service period based on the grant-date fair value of the awards.
Restructuring Costs	Restructuring Costs — The Company records liabilities for costs associated with exit or disposal activities in the period in which the liability is incurred. In accordance with existing benefit arrangements, employee termination costs are accrued when the restructuring actions are probable and estimable. When accruing these costs, the Company will recognize the amount within a range of costs that is the best estimate within the range. When no amount within the range is a better estimate than any other amount, the Company recognizes the minimum amount within the range. Costs for one-time termination benefits in which the employee is required to render service until termination in order to receive the benefits are recognized ratably over the future service period.
Contingencies and Legal Defense Costs	Contingencies and Legal Defense Costs — The Company records accruals for contingencies and legal defense costs expected to be incurred in connection with a loss contingency when it is probable that a liability has been incurred and the amount can be reasonably estimated.
Taxes on Income	Taxes on Income — Deferred taxes are recognized for the future tax effects of temporary differences between financial and income tax reporting based on enacted tax laws and rates. The Company evaluates tax positions to determine whether the benefits of tax positions are more likely than not of being sustained upon audit based on the technical merits of the tax position. For tax positions that are more likely than not of being sustained upon audit, the Company recognizes the largest amount of the benefit that is greater than 50% likely of being realized upon ultimate settlement in the financial statements. For tax positions that are not more likely than not of being sustained upon audit, the Company does not recognize any portion of the benefit in the financial statements. The Company recognizes interest and penalties associated with uncertain tax positions as a component of Taxes on income in the Consolidated Statement of Income.
Use of Estimates	Use of Estimates — The consolidated financial statements are prepared in conformity with accounting principles generally accepted in the United States (“GAAP”) and, accordingly, include certain amounts that are based on management’s best estimates and judgments. Estimates are used when accounting for amounts recorded in connection with mergers and acquisitions, including initial fair value determinations of assets and liabilities, primarily IPR&D and other intangible assets, as well as subsequent fair value measurements. Additionally, estimates are used in determining such items as provisions for sales discounts and returns, depreciable and amortizable lives, recoverability of inventories, including those produced in preparation for product launches, amounts recorded for contingencies, environmental liabilities and other reserves, pension and other postretirement benefit plan assumptions, share-based compensation assumptions, restructuring costs, impairments of long-lived assets (including intangible assets and goodwill) and investments, and taxes on income. Because of the uncertainty inherent in such estimates, actual results may differ from these estimates.
Reclassifications	Reclassifications — Certain reclassifications have been made to prior year amounts to conform to the current year presentation.
Recently Adopted Accounting Standards	Recently Issued Accounting Standards — In May 2014, the Financial Accounting Standards Board issued amended accounting guidance on revenue recognition that will be applied to all contracts with customers. The objective of the new guidance is to improve comparability of revenue recognition practices across entities and to provide more useful information to users of financial statements through improved disclosure requirements. This guidance is effective for annual and interim periods beginning in 2017. Early adoption is not permitted. The Company is currently assessing the impact of adoption on its consolidated financial statements.

Restructuring_Tables

Restructuring (Tables)	12 Months Ended
	Dec. 31, 2014
Restructuring and Related Activities [Abstract]
Charges Related to Restructuring Program Activities by Type of Cost	The following table summarizes the charges related to restructuring program activities by type of cost:


	Year Ended December 31, 2014	Separation				Accelerated				Other				Total
		Costs				Depreciation
	2013 Restructuring Program
	Materials and production	$	—			$	204			$	23			$	227

	Marketing and administrative	—				142				3				145

	Research and development	—				273				9				282

	Restructuring costs	566				—				28				594

		566				619				63				1,248

	Merger Restructuring Program
	Materials and production	—				225				30				255

	Marketing and administrative	—				56				(1		)		55

	Research and development	—				—				1				1

	Restructuring costs	108				—				311				419

		108				281				341				730

		$	674			$	900			$	404			$	1,978

	Year Ended December 31, 2013
	2013 Restructuring Program
	Materials and production	$	—			$	186			$	7			$	193

	Marketing and administrative	—				72				3				75

	Research and development	—				76				(1		)		75

	Restructuring costs	866				—				32				898

		866				334				41				1,241

	Merger Restructuring Program

	Materials and production	—				151				98				249

	Marketing and administrative	—				63				3				66

	Research and development	—				27				(1		)		26

	Restructuring costs	481				—				284				765

		481				241				384				1,106

	2008 Restructuring Program
	Materials and production	—				(2		)		6				4

	Marketing and administrative	—				4				—				4

	Restructuring costs	34				—				12				46

		34				2				18				54

		$	1,381			$	577			$	443			$	2,401

Year Ended December 31, 2012
Merger Restructuring Program
Materials and production	$	—			$	92			$	70			$	162

Marketing and administrative	—				75				6				81

Research and development	—				53				4				57

Restructuring costs	497				—				154				651

	497				220				234				951

2008 Restructuring Program
Materials and production	—				7				19				26

Marketing and administrative	—				8				1				9

Restructuring costs	(8		)		—				21				13

	(8		)		15				41				48

	$	489			$	235			$	275			$	999

Charges and Spending Relating to Restructuring Activities by Program	The following table summarizes the charges and spending relating to restructuring activities by program:


		Separation				Accelerated				Other				Total
		Costs				Depreciation
	2013 Restructuring Program
	Restructuring reserves January 1, 2013	$	—			$	—			$	—			$	—

	Expenses	866				334				41				1,241

	(Payments) receipts, net	(121		)		—				9				(112		)

	Non-cash activity	—				(334		)		(27		)		(361		)

	Restructuring reserves December 31, 2013	745				—				23				768

	Expenses	566				619				63				1,248

	(Payments) receipts, net	(816		)		—				(124		)		(940		)

	Non-cash activity	—				(619		)		52				(567		)

	Restructuring reserves December 31, 2014 (1)	$	495			$	—			$	14			$	509

	Merger Restructuring Program
	Restructuring reserves January 1, 2013	$	699			$	—			$	19			$	718

	Expenses	481				241				384				1,106

	(Payments) receipts, net	(517		)		—				(258		)		(775		)

	Non-cash activity	62				(241		)		(133		)		(312		)

	Restructuring reserves December 31, 2013	725				—				12				737

	Expenses	108				281				341				730

	(Payments) receipts, net	(297		)		—				(232		)		(529		)

	Non-cash activity	—				(281		)		(115		)		(396		)

	Restructuring reserves December 31, 2014 (1)	$	536			$	—			$	6			$	542


	(1)	The cash outlays associated with the 2013 Restructuring Program are expected to be substantially completed by the end of 2015. The non-manufacturing cash outlays associated with the Merger Restructuring Program were substantially completed by the end of 2013; the remaining cash outlays are expected to be substantially completed by the end of 2016.

Financial_Instruments_Tables

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Interest Rate Derivatives	At December 31, 2014, the Company was a party to 17 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 as detailed in the table below.


		2014
	Debt Instrument	Par Value of Debt				Number of Interest Rate Swaps Held			Total Swap Notional Amount
	0.70% notes due 2016	$	1,000			4			$	1,000

	1.30% notes due 2018	1,000				4			1,000

	5.00% notes due 2019	1,250				3			550

	3.875% notes due 2021	1,150				5			1,150

	2.40% notes due 2022	1,000				1			250

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 as of December 31:


				2014												2013
				Fair Value of								U.S. Dollar				Fair Value of								U.S. Dollar
				Derivative								Notional				Derivative								Notional
		Balance Sheet Caption		Asset				Liability								Asset				Liability
	Derivatives Designated as Hedging Instruments
	Interest rate swap contracts (non-current)	Other assets		$	19			$	—			$	1,950			$	13			$	—			$	1,550

	Interest rate swap contracts (non-current)	Other noncurrent liabilities		—				15				2,000				—				25				2,000

	Foreign exchange contracts (current)	Deferred income taxes and other current assets		772				—				5,513				493				—				4,427

	Foreign exchange contracts (non-current)	Other assets		691				—				6,253				515				—				6,676

	Foreign exchange contracts (current)	Accrued and other current liabilities		—				—				—				—				19				1,659

				$	1,482			$	15			$	15,716			$	1,021			$	44			$	16,312

	Derivatives Not Designated as Hedging Instruments
	Foreign exchange contracts (current)	Deferred income taxes and other current assets		$	365			$	—			$	6,966			$	69			$	—			$	5,705

	Foreign exchange contracts (current)	Accrued and other current liabilities		—				88				3,386				—				140				7,892

				$	365			$	88			$	10,352			$	69			$	140			$	13,597

				$	1,847			$	103			$	26,068			$	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 at December 31:


		2014								2013
		Asset				Liability				Asset				Liability
	Gross amounts recognized in the consolidated balance sheet	$	1,847			$	103			$	1,090			$	184

	Gross amount subject to offset in master netting arrangements not offset in the consolidated balance sheet	(97		)		(97		)		(147		)		(147		)
	Cash collateral (received) posted	(1,410		)		—				(652		)		—

	Net amounts	$	340			$	6			$	291			$	37

Location and Pretax Gain or Loss Amounts for Derivatives	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:



	Years Ended December 31	2014				2013				2012
	Derivatives designated in a fair value hedging relationship
	Interest rate swap contracts
	Amount of (gain) loss recognized in Other (income) expense, net on derivatives (1)	$	(17	)		$	12			$	—

	Amount of loss (gain) recognized in Other (income) expense, net on hedged item (1)	14				(14		)		—

	Derivatives designated in foreign currency cash flow hedging relationships
	Foreign exchange contracts
	Amount of (gain) loss reclassified from AOCI to Sales	(143		)		45				50

	Amount of (gain) loss recognized in OCI on derivatives	(775		)		(306		)		204

	Derivatives designated in foreign currency net investment hedging relationships
	Foreign exchange contracts
	Amount of gain recognized in Other (income) expense, net on derivatives (2)	(6		)		(10		)		(20		)
	Amount of gain recognized in OCI on derivatives	(192		)		(363		)		(208		)
	Derivatives not designated in a hedging relationship
	Foreign exchange contracts
	Amount of (gain) loss recognized in Other (income) expense, net on derivatives (3)	(516		)		183				382

	Amount of loss recognized in Sales	15				8				30


	(1)	There was $3 million and $2 million of ineffectiveness on the hedge during 2014 and 2013, respectively.

	(2)	There was no ineffectiveness on the hedge. Represents the amount excluded from hedge effectiveness testing.

	(3)	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 at December 31 is as follows:



		2014																2013
		Fair				Amortized				Gross Unrealized								Fair				Amortized				Gross Unrealized
		Value				Cost				Gains				Losses				Value				Cost				Gains		Losses
	Corporate notes and bonds	$	10,107			$	10,102			$	22			$	(17	)		$	7,054			$	7,037			$	32	$	(15	)

	Commercial paper	6,970				6,970				—				—				1,206				1,206				—		—

	U.S. government and agency securities	1,774				1,775				1				(2		)		1,236				1,239				1		(4		)

	Asset-backed securities	1,460				1,462				1				(3		)		1,300				1,303				1		(4		)

	Mortgage-backed securities	602				604				2				(4		)		476				479				2		(5		)

	Foreign government bonds	385				385				—				—				125				126				—		(1		)

	Equity securities	730				557				173				—				471				397				74		—

		$	22,028			$	21,855			$	199			$	(26	)		$	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 at December 31 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)
		2014																2013
	Assets
	Investments
	Corporate notes and bonds	$	—			$	10,107			$	—			$	10,107			$	—			$	7,054			$	—	$	7,054

	Commercial paper	—				6,970				—				6,970				—				1,206				—		1,206

	U.S. government and agency securities	—				1,774				—				1,774				—				1,236				—		1,236

	Asset-backed securities (1)	—				1,460				—				1,460				—				1,300				—		1,300

	Mortgage-backed securities (1)	—				602				—				602				—				476				—		476

	Foreign government bonds	—				385				—				385				—				125				—		125

	Equity securities	495				—				—				495				238				—				—		238

		495				21,298				—				21,793				238				11,397				—		11,635

	Other assets
	Securities held for employee compensation	181				54				—				235				186				47				—		233

	Derivative assets (2)
	Purchased currency options	—				1,252				—				1,252				—				868				—		868

	Forward exchange contracts	—				576				—				576				—				209				—		209

	Interest rate swaps	—				19				—				19				—				13				—		13

		—				1,847				—				1,847				—				1,090				—		1,090

	Total assets	$	676			$	23,199			$	—			$	23,875			$	424			$	12,534			$	—	$	12,958

	Liabilities
	Other liabilities
	Contingent consideration	$	—			$	—			$	428			$	428			$	—			$	—			$	69	$	69

	Derivative liabilities (2)
	Forward exchange contracts	—				46				—				46				—				134				—		134

	Written currency options	—				42				—				42				—				25				—		25

	Interest rate swaps	—				15				—				15				—				25				—		25

		—				103				—				103				—				184				—		184

	Total liabilities	$	—			$	103			$	428			$	531			$	—			$	184			$	69	$	253


	(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.
Summarized Information about the Changes in Liabilities for Contingent Consideration	Summarized information about the changes in liabilities for contingent consideration is as follows:


		2014				2013
	Fair value January 1	$	69			$	49

	Changes in fair value (recorded in Research and development expenses)	316				8

	Additions	43				12

	Fair value December 31	$	428			$	69

Inventories_Tables

Inventories (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventories	Inventories at December 31 consisted of:


		2014		2013
	Finished goods	$	1,588	$	1,738

	Raw materials and work in process	5,141		5,894

	Supplies	197		225

	Total (approximates current cost)	6,926		7,857

	Increase to LIFO costs	309		73

		$	7,235	$	7,930

	Recognized as:
	Inventories	$	5,571	$	6,226

	Other assets	1,664		1,704

Goodwill_and_Other_Intangibles1

Goodwill and Other Intangibles (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill Activity by Segment	The following table summarizes goodwill activity by segment:



		Pharmaceutical			All Other			Total

	Balance January 1, 2013	$	10,086		$	2,048		$	12,134

	Acquisitions	103			188			291

	Divestitures	(45		)	—			(45		)

	Other (1)	(79		)	—			(79		)

	Balance December 31, 2013	10,065			2,236			12,301

	Acquisitions	1,369			38			1,407

	Divestitures	(200		)	(362		)	(562		)
	Impairments	(93		)	—			(93		)

	Other (1)	(33		)	(28		)	(61		)
	Balance December 31, 2014 *(2)*	$	11,108		$	1,884		$	12,992

	(1) Other includes cumulative translation adjustments on goodwill balances and certain other adjustments.
	(2) Accumulated goodwill impairment losses at December 31, 2014 were $93 million.
Other Intangibles	Other intangibles at December 31 consisted of:


		2014									2013
		Gross			Accumulated			Net			Gross		Accumulated		Net
		Carrying			Amortization						Carrying		Amortization
		Amount									Amount
	Products and product rights	$	38,714		$	23,830		$	14,884		$	41,691	$	21,216	$	20,475

	In-process research and development	4,345			—			4,345			1,856		—		1,856

	Tradenames	198			71			127			1,632		310		1,322

	Other	1,527			497			1,030			958		810		148

		$	44,784		$	24,398		$	20,386		$	46,137	$	22,336	$	23,801

Joint_Ventures_and_Other_Equit1

Joint Ventures and Other Equity Method Affiliates (Tables)	12 Months Ended
	Dec. 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:


	Years Ended December 31	2014		2013		2012
	AstraZeneca LP (1)	$	192	$	352	$	621

	Other (2)	65		52		21

		$	257	$	404	$	642


	(1)	As noted below, as of July 1, 2014, the Company no longer records equity income from AZLP.

	(2)	Includes results from Sanofi Pasteur MSD.
Summarized Financial Information for AZLP	Summarized financial information for AZLP is as follows:


	Years Ended December 31	2014 *(1)*		2013		2012
	Sales	$	2,205	$	4,611	$	4,694

	Materials and production costs	1,044		2,222		2,177

	Other expense, net	604		1,175		1,312

	Income before taxes (2)	557		1,214		1,205



	December 31	2013
	Current assets	$	4,832

	Noncurrent assets	182

	Current liabilities	3,958

	(1) Includes results through the June 30, 2014 termination date.
	(2) Merck’s partnership returns from AZLP were generally contractually determined as noted above and were not based on a percentage of income from AZLP, other than with respect to Merck’s 1% limited partnership interest.
Summarized Financial Information for Affiliates (Excluding AZLP)	Summarized information for those affiliates (excluding AZLP disclosed separately above) is as follows:


	Years Ended December 31	2014		2013		2012
	Sales	$	1,370	$	1,326	$	1,295

	Materials and production costs	577		581		573

	Other expense, net	641		691		705

	Income before taxes	152		54		17



	December 31	2014		2013
	Current assets	$	1,819	$	1,486

	Noncurrent assets	208		149

	Current liabilities	469		456

	Noncurrent liabilities	129		154

Loans_Payable_LongTerm_Debt_an1

Loans Payable, Long-Term Debt and Other Commitments (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Long-Term Debt	Long-term debt at December 31 consisted of:


		2014		2013
	2.80% notes due 2023	$	1,749	$	1,749

	5.00% notes due 2019	1,291		1,293

	4.15% notes due 2043	1,246		1,246

	1.125% euro-denominated notes due 2021	1,218		—

	1.875% euro-denominated notes due 2026	1,210		—

	3.875% notes due 2021	1,150		1,148

	2.40% notes due 2022	1,000		1,000

	Floating-rate borrowing due 2018	1,000		1,000

	1.10% notes due 2018	999		998

	0.70% notes due 2016	998		997

	1.30% notes due 2018	984		975

	2.25% notes due 2016	858		866

	6.50% notes due 2033	812		1,306

	2.50% euro-denominated notes due 2034	603		—

	6.55% notes due 2037	597		1,143

	Floating-rate borrowing due 2016	500		500

	3.60% notes due 2042	493		492

	5.85% notes due 2039	418		749

	5.75% notes due 2036	371		498

	5.95% debentures due 2028	356		498

	6.40% debentures due 2028	326		499

	6.30% debentures due 2026	152		249

	6.00% notes due 2017	—		1,095

	4.00% notes due 2015	—		1,029

	4.75% notes due 2015	—		1,023

	Other	368		186

		$	18,699	$	20,539

Equity_Tables

Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Summary of Common Stock and Treasury Stock Transactions	A summary of common stock and treasury stock transactions (shares in millions) is as follows:


		2014			2013			2012
		Common	Treasury		Common	Treasury		Common	Treasury
		Stock	Stock		Stock	Stock		Stock	Stock
	Balance January 1	3,577	650		3,577	550		3,577	536

	Purchases of treasury stock (1)	—	134		—	139		—	62

	Issuances (2)	—	(45	)	—	(39	)	—	(48	)

	Balance December 31	3,577	739		3,577	650		3,577	550


	(1)	Purchases of treasury stock in 2013 include 105 million shares purchased pursuant to an accelerated share repurchase agreement as discussed below.

	(2)	Issuances primarily reflect activity under share-based compensation plans.

ShareBased_Compensation_Plans_

Share-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Assumptions Used to Determine Weighted-Average Fair Value of Options Granted	The weighted average fair value of options granted in 2014, 2013 and 2012 was $6.79, $6.21 and $5.47 per option, respectively, and were determined using the following assumptions:


	Years Ended December 31	2014			2013			2012
	Expected dividend yield	4.3	%		4.2	%		4.4	%
	Risk-free interest rate	2	%		1.2	%		1.3	%
	Expected volatility	22	%		25	%		25.2	%
	Expected life (years)	6.4			7			7

Summarized Information Relative to Stock Option Plan Activity	Summarized information relative to stock option plan activity (options in thousands) is as follows:


		Number			Weighted				Weighted		Aggregate
		of Options			Average				Average		Intrinsic
					Exercise				Remaining		Value
					Price				Contractual
									Term (Years)
	Outstanding January 1, 2014	115,805			$	38.75

	Granted	4,872			58.14

	Exercised	(39,293	)		39.71

	Forfeited	(5,249	)		45.28

	Outstanding December 31, 2014	76,135			$	39.05			3.85		$	1,358

	Exercisable December 31, 2014	65,324			$	37.56			3.21		$	1,257

Additional Information Pertaining to Stock Option Plans	Additional information pertaining to stock option plans is provided in the table below:


	Years Ended December 31	2014				2013				2012
	Total intrinsic value of stock options exercised	$	626			$	374			$	528

	Fair value of stock options vested	35				42				80

	Cash received from the exercise of stock options	1,560				1,210				1,310

Summary of Nonvested RSU and PSU Activity	A summary of nonvested RSU and PSU activity (shares in thousands) is as follows:


			RSUs							PSUs
			Number			Weighted				Number			Weighted
			of Shares			Average				of Shares			Average
						Grant Date							Grant Date
						Fair Value							Fair Value
	Nonvested January 1, 2014		19,134			$	40.07			1,673			$	35.98

	Granted		4,776			58.13				1,224			62.94

	Vested		(6,866	)		36.36				(723	)		33.97

	Forfeited		(1,410	)		46.22				(292	)		45.49

	Nonvested December 31, 2014		15,634			$	46.66			1,882			$	52.81

Pension_and_Other_Postretireme1

Pension and Other Postretirement Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Components of Net Periodic Benefit Cost	The net periodic benefit cost for pension and other postretirement benefit plans consisted of the following components:


		Pension Benefits
		U.S.												International												Other Postretirement Benefits
	Years Ended December 31	2014				2013				2012				2014				2013				2012				2014				2013			2012
	Service cost	$	300			$	386			$	324			$	266			$	296			$	231			$	78			$	102		$	82

	Interest cost	425				402				401				269				263				260				115				107			121

	Expected return on plan assets	(782		)		(721		)		(617		)		(416		)		(376		)		(354		)		(139		)		(126		)	(136		)
	Net amortization	74				251				149				59				85				36				(71		)		(50		)	(35		)

	Termination benefits	53				51				17				11				7				10				22				50			18

	Curtailments	(69		)		(22		)		(11		)		(4		)		(1		)		2				(39		)		(11		)	(7		)

	Settlements	11				1				5				6				22				13				—				—			—

	Net periodic benefit cost (credit)	$	12			$	348			$	268			$	191			$	296			$	198			$	(34	)		$	72		$	43

Obligation and Funded Status	Summarized information about the changes in plan assets and benefit obligations, the funded status and the amounts recorded at December 31 is as follows:


		Pension Benefits																Other
																		Postretirement
		U.S.								International								Benefits
		2014				2013				2014				2013				2014				2013
	Fair value of plan assets January 1	$	10,007			$	8,683			$	7,428			$	6,666			$	1,913			$	1,760

	Actual return on plan assets	484				1,821				1,099				703				114				199

	Company contributions	92				54				276				591				67				73

	Effects of exchange rate changes	—				—				(816		)		(84		)		—				—

	Benefits paid	(535		)		(542		)		(245		)		(238		)		(110		)		(119		)
	Settlements	(64		)		(9		)		(31		)		(227		)		—				—

	Other	—				—				13				17				—				—

	Fair value of plan assets December 31	$	9,984			$	10,007			$	7,724			$	7,428			$	1,984			$	1,913

	Benefit obligation January 1	8,666				9,961				7,389				7,685				2,329				2,650

	Service cost	300				386				266				296				78				102

	Interest cost	425				402				269				263				115				107

	Actuarial losses (gains)	1,857				(1,565		)		1,605				(124		)		212				(428		)

	Benefits paid	(535		)		(542		)		(245		)		(238		)		(110		)		(119		)
	Effects of exchange rate changes	—				—				(864		)		(21		)		(6		)		(5		)

	Plan amendments	—				1				(4		)		(226		)		—				(38		)

	Curtailments	(70		)		(19		)		(76		)		(42		)		3				—

	Termination benefits	53				51				11				7				22				50

	Settlements	(64		)		(9		)		(31		)		(227		)		—				—

	Other	—				—				11				16				(5		)		10

	Benefit obligation December 31	$	10,632			$	8,666			$	8,331			$	7,389			$	2,638			$	2,329

	Funded status December 31	$	(648	)		$	1,341			$	(607	)		$	39			$	(654	)		$	(416	)

	Recognized as:
	Other assets	$	68			$	2,106			$	565			$	705			$	1			$	—

	Accrued and other current liabilities	(41		)		(44		)		(11		)		(9		)		(11		)		(8		)
	Other noncurrent liabilities	(675		)		(721		)		(1,161		)		(657		)		(644		)		(408		)
Schedule of Accumulated and Projected Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]	Information related to the funded status of selected pension plans at December 31 is as follows:


		U.S.								International
		2014				2013				2014				2013
	Pension plans with a projected benefit obligation in excess of plan assets
	Projected benefit obligation	$	3,963			$	764			$	5,513			$	2,196

	Fair value of plan assets	3,247				—				4,341				1,529

	Pension plans with an accumulated benefit obligation in excess of plan assets
	Accumulated benefit obligation	$	810			$	619			$	2,749			$	1,871

	Fair value of plan assets	138				—				1,870				1,424

Summary of Changes in Fair Value of Company's Level 3 Pension Plan Assets	The table below provides a summary of the changes in fair value, including transfers in and/or out, of all financial assets measured at fair value using significant unobservable inputs (Level 3) for the Company’s pension plan assets:


		2014																2013
		Insurance				Real				Other				Total				Insurance				Real				Other				Total
		Contracts				Estate												Contracts				Estate
	U.S. Pension Plans
	Balance January 1	$	—			$	—			$	31			$	31			$	—			$	—			$	32			$	32

	Actual return on plan assets:
	Relating to assets still held at December 31	—				—				1				1				—				—				1				1

	Relating to assets sold during the year	—				—				4				4				—				—				3				3

	Purchases	—				—				1				1				—				—				2				2

	Sales	—				—				(9		)		(9		)		—				—				(7		)		(7		)

	Balance December 31	$	—			$	—			$	28			$	28			$	—			$	—			$	31			$	31

	International Pension Plans
	Balance January 1	$	540			$	49			$	2			$	591			$	496			$	141			$	23			$	660

	Actual return on plan assets:
	Relating to assets still held at December 31	(35		)		(4		)		—				(39		)		30				—				—				30

	Relating to assets sold during the year	—				—				—				—				1				(1		)		—				—

	Purchases	22				—				—				22				18				—				—				18

	Sales	(3		)		(10		)		—				(13		)		(2		)		—				(21		)		(23		)

	Transfers out of Level 3	(3		)		(6		)		—				(9		)		(3		)		(91		)		—				(94		)

	Balance December 31	$	521			$	29			$	2			$	552			$	540			$	49			$	2			$	591

Summary of Expected Benefit Payments	Expected benefit payments are as follows:


		U.S. Pension Benefits				International Pension				Other
						Benefits				Postretirement
										Benefits
	2015	$	469			$	213			$	109

	2016	495				185				117

	2017	491				192				124

	2018	525				206				131

	2019	549				215				138

	2020 — 2024	3,238				1,323				792

Components of Other Comprehensive Income	The following amounts were reflected as components of OCI:


		Pension Plans																								Other Postretirement
		U.S.												International												Benefit Plans
	Years Ended December 31	2014				2013				2012				2014				2013				2012				2014				2013			2012
	Net (loss) gain arising during the period	$	(2,085	)		$	2,676			$	(688	)		$	(779	)		$	513			$	(1,219	)		$	(223	)		$	499		$	(24	)

	Prior service (cost) credit arising during the period	(59		)		(23		)		(16		)		(8		)		226				3				(42		)		26			78

		$	(2,144	)		$	2,653			$	(704	)		$	(787	)		$	739			$	(1,216	)		$	(265	)		$	525		$	54

	Net loss amortization included in benefit cost	$	135			$	318			$	217			$	74			$	89			$	39			$	1			$	23		$	31

	Prior service (credit) cost amortization included in benefit cost	(61		)		(67		)		(68		)		(15		)		(4		)		(3		)		(72		)		(73		)	(66		)
		$	74			$	251			$	149			$	59			$	85			$	36			$	(71	)		$	(50	)	$	(35	)

Summary of Weighted Average Assumptions Used in Determining Pension Plan and U.S. Pension and Other Postretirement Benefit Plan Information	The Company reassesses its benefit plan assumptions on a regular basis. The weighted average assumptions used in determining U.S. pension and other postretirement benefit plan and international pension plan information are as follows:


		U.S. Pension and Other									International Pension Plans
		Postretirement Benefit Plans
	December 31	2014			2013			2012			2014			2013			2012

	Net periodic benefit cost
	Discount rate	4.9	%		4.1	%		4.8	%		3.8	%		3.6	%		4.6	%
	Expected rate of return on plan assets	8.5	%		8.5	%		8.7	%		6	%		5.8	%		5.9	%
	Salary growth rate	4.5	%		4.5	%		4.5	%		3.1	%		3.3	%		3.4	%
	Benefit obligation
	Discount rate	4.2	%		5.1	%		4.1	%		2.7	%		3.8	%		3.6	%
	Salary growth rate	4.4	%		4.5	%		4.5	%		2.9	%		3.1	%		3.3	%
Summary of Health Care Cost Trend Rate Assumptions for Other Postretirement Benefit Plans	The health care cost trend rate assumptions for other postretirement benefit plans are as follows:


	December 31	2014			2013
	Health care cost trend rate assumed for next year	6.9	%		7.1	%
	Rate to which the cost trend rate is assumed to decline	4.6	%		4.6	%
	Year that the trend rate reaches the ultimate trend rate	2027			2027

One Percentage Point Change in Health Care Cost Trend Rate	A one percentage point change in the health care cost trend rate would have had the following effects:


		One Percentage Point
		Increase				Decrease
	Effect on total service and interest cost components	$	32			$	(27	)

	Effect on benefit obligation	421				(339		)

Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Values of Pension Plan and Other Postretirement Benefit Plan Assets	The fair values of the Company’s pension plan assets at December 31 by asset category are as follows:


		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)
		2014																2013
	U.S. Pension Plans
	Assets
	Cash and cash equivalents	$	2			$	234			$	—			$	236			$	(54	)		$	223			$	—			$	169

	Investment funds
	Developed markets equities	540				4,518				—				5,058				581				4,772				—				5,353

	Emerging markets equities	107				718				—				825				100				734				—				834

	Government and agency obligations	—				31				—				31				—				29				—				29

	Fixed income obligations	—				132				—				132				—				125				—				125

	Equity securities
	Developed markets	2,169				—				—				2,169				2,138				—				—				2,138

	Fixed income securities
	Government and agency obligations	—				516				—				516				—				444				—				444

	Corporate obligations	—				722				—				722				—				590				—				590

	Mortgage and asset-backed securities	—				245				—				245				—				245				—				245

	Other investments
	Derivatives	1				31				—				32				1				—				—				1

	Other	—				—				28				28				—				48				31				79

	Liabilities
	Derivatives	—				10				—				10				—				—				—				—

		$	2,819			$	7,137			$	28			$	9,984			$	2,766			$	7,210			$	31			$	10,007

	International Pension Plans
	Assets
	Cash and cash equivalents	$	208			$	13			$	—			$	221			$	142			$	24			$	—			$	166

	Investment funds

	Developed markets equities	217				2,991				—				3,208				227				2,872				—				3,099

	Emerging markets equities	31				256				—				287				63				302				—				365

	Government and agency obligations	317				1,410				—				1,727				293				1,151				—				1,444

	Corporate obligations	183				170				—				353				188				77				—				265

	Fixed income obligations	9				16				—				25				17				20				—				37

	Real estate (1)	—				8				29				37				4				57				49				110

	Equity securities

	Developed markets	509				—				—				509				407				—				—				407

Fixed income securities

Government and agency obligations	28				448				—				476				2				652				—				654

Corporate obligations	2				190				1				193				—				151				—				151

Mortgage and asset-backed securities	—				90				—				90				—				54				—				54

Other investments

Insurance contracts (2)	—				69				521				590				—				128				540				668

Other	3				4				1				8				—				6				2				8

	$	1,507			$	5,665			$	552			$	7,724			$	1,343			$	5,494			$	591			$	7,428


(1)	The plans’ Level 3 investments in real estate funds are generally valued by market appraisals of the underlying investments in the funds.

(2)	The plans’ Level 3 investments in insurance contracts are generally valued using a crediting rate that approximates market returns and invest in underlying securities whose market values are unobservable and determined using pricing models, discounted cash flow methodologies, or similar techniques.
Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair Values of Pension Plan and Other Postretirement Benefit Plan Assets	The fair values of the Company’s other postretirement benefit plan assets at December 31 by asset category are as follows:


		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)
		2014																2013
	Assets
	Cash and cash equivalents	$	60			$	20			$	—			$	80			$	47			$	20			$	—			$	67

	Investment funds
	Developed markets equities	51				613				—				664				54				667				—				721

	Emerging markets equities	36				93				—				129				36				95				—				131

	Government and agency obligations	3				2				—				5				—				—				—				—

	Fixed income obligations	—				12				—				12				3				14				—				17

	Equity securities
	Developed markets	204				—				—				204				199				—				—				199

	Fixed income securities
	Government and agency obligations	—				333				—				333				—				257				—				257

	Corporate obligations	—				336				—				336				—				281				—				281

	Mortgage and asset-backed securities	—				219				—				219				—				219				—				219

	Other fixed income obligations	—				—				—				—				—				21				—				21

	Other investments
	Derivatives	—				2				—				2				—				—				—				—

		$	354			$	1,630			$	—			$	1,984			$	339			$	1,574			$	—			$	1,913

Other_Income_Expense_Net_Table

Other (Income) Expense, Net (Tables)	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Other (Income) Expense, Net	Other (income) expense, net, consisted of:


	Years Ended December 31	2014			2013			2012
	Interest income	$	(266	)	$	(264	)	$	(232	)
	Interest expense	732			801			714

	Exchange losses	180			290			185

	Other, net	(12,002		)	(12		)	449

		$	(11,356	)	$	815		$	1,116

Taxes_on_Income_Tables

Taxes on Income (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Reconciliation Between Effective Tax Rate and U.S. Statutory Rate	A reconciliation between the effective tax rate and the U.S. statutory rate is as follows:


		2014						2013							2012
		Amount			Tax Rate			Amount				Tax Rate			Amount			Tax Rate
	U.S. statutory rate applied to income before taxes	$	6,049		35	%		$	1,941			35	%		$	3,059		35	%

	Differential arising from:
	Foreign earnings	(1,486		)	(8.6	)		(1,316		)		(23.7	)		(1,955		)	(22.4	)
	AstraZeneca option exercise	(774		)	(4.5	)		—				—			—			—

	Sale of Sirna Therapeutics, Inc.	(357		)	(2.1	)		—				—			—			—

	Tax settlements	(89		)	(0.5	)		(497		)		(9.0	)		(113		)	(1.3	)
	The American Taxpayer Relief Act of 2012	—			—			(269		)		(4.8	)		—			—

	Unremitted foreign earnings	(209		)	(1.2	)		(81		)		(1.5	)		(11		)	(0.1	)
	Amortization of purchase accounting adjustments	865			5			934				16.8			905			10.3

	Divestiture of Merck Consumer Care	440			2.5			—				—			—			—

	Restructuring	289			1.7			224				4			62			0.7

	U.S. health care reform legislation	134			0.8			65				1.2			60			0.7

	Intangible asset impairment charges	148			0.9			56				1			40			0.5

	Vioxx and ENHANCE litigation settlements	—			—			—				—			98			1.2

	State taxes	7			—			44				0.8			31			0.3

	Other (1)	332			1.9			(73		)		(1.3	)		264			3

		$	5,349		30.9	%		$	1,028			18.5	%		$	2,440		27.9	%


	(1)	Other includes the tax effect of contingency reserves, research credits, tax rate changes and miscellaneous items.
Income Before Taxes	Income before taxes consisted of:


	Years Ended December 31	2014			2013				2012
	Domestic	$	15,730		$	3,513			$	4,500

	Foreign	1,553			2,032				4,239

		$	17,283		$	5,545			$	8,739

Taxes on Income	Taxes on income consisted of:


	Years Ended December 31	2014			2013				2012
	Current provision
	Federal	$	7,136		$	568			$	1,346

	Foreign	438			923				651

	State	375			(133		)		(226		)

		7,949			1,358				1,771

	Deferred provision
	Federal	(2,162		)	30				749

	Foreign	(201		)	(398		)		(323		)
	State	(237		)	38				243

		(2,600		)	(330		)		669

		$	5,349		$	1,028			$	2,440

Deferred Income Taxes	Deferred income taxes at December 31 consisted of:


		2014							2013
		Assets			Liabilities				Assets				Liabilities
	Intangibles	$	—		$	3,358			$	—			$	3,772

	Inventory related	56			699				49				604

	Accelerated depreciation	58			892				125				1,215

	Unremitted foreign earnings	—			2,016				—				2,361

	Equity investments	5			—				—				539

	Pensions and other postretirement benefits	778			156				162				543

	Compensation related	578			—				600				—

	Unrecognized tax benefits	401			—				497				—

	Net operating losses and other tax credit carryforwards	379			—				225				—

	Other	1,530			65				1,605				71

	Subtotal	3,785			7,186				3,263				9,105

	Valuation allowance	(265		)					(205		)
	Total deferred taxes	$	3,520		$	7,186			$	3,058			$	9,105

	Net deferred income taxes				$	3,666							$	6,047

	Recognized as:
	Deferred income taxes and other current assets	$	568						$	572

	Other assets	401							381

	Income taxes payable				$	369							$	224

	Deferred income taxes				4,266								6,776

Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:


		2014			2013				2012
	Balance January 1	$	3,503		$	4,425			$	4,277

	Additions related to current year positions	389			320				496

	Additions related to prior year positions	23			177				58

	Reductions for tax positions of prior years (1)	(156		)	(747		)		(320		)
	Settlements	(161		)	(603		)		(67		)
	Lapse of statute of limitations	(64		)	(69		)		(19		)
	Balance December 31	$	3,534		$	3,503			$	4,425


	(1)	Amounts reflect the settlements with the IRS and CRA as discussed below.

Earnings_per_Share_Tables

Earnings per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Calculations of Earnings Per Share	The calculations of earnings per share are as follows:


	Years Ended December 31	2014		2013		2012
	Basic Earnings per Common Share
	Net income attributable to Merck & Co., Inc.	$	11,920	$	4,404	$	6,168

	Less: Income allocated to participating securities	—		—		3

	Net income allocated to common shareholders	$	11,920	$	4,404	$	6,165

	Average common shares outstanding	2,894		2,963		3,041

		$	4.12	$	1.49	$	2.03

	Earnings per Common Share Assuming Dilution
	Net income attributable to Merck & Co., Inc.	$	11,920	$	4,404	$	6,168

	Less: Income allocated to participating securities	—		—		3

	Net income allocated to common shareholders	$	11,920	$	4,404	$	6,165

	Average common shares outstanding	2,894		2,963		3,041

	Common shares issuable (1)	34		33		35

	Average common shares outstanding assuming dilution	2,928		2,996		3,076

		$	4.07	$	1.47	$	2


	(1)	Issuable primarily under share-based compensation plans.

Other_Comprehensive_Income_Los1

Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2014
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Components of Accumulated Other Comprehensive Income (Loss)	Changes in AOCI by component are as follows:


		Derivatives				Investments				Employee				Cumulative			Accumulated Other
										Benefit				Translation			Comprehensive
										Plans				Adjustment			Income (Loss)
	Balance January 1, 2012, net of taxes	$	4			$	21			$	(2,346	)		$	(811	)	$	(3,132	)

	Other comprehensive income (loss) before reclassification adjustments, pretax	(198		)		74				(1,852		)		(99		)	(2,075		)

	Tax	77				(10		)		450				(81		)	436

	Other comprehensive income (loss) before reclassification adjustments, net of taxes	(121		)		64				(1,402		)		(180		)	(1,639		)

	Reclassification adjustments, pretax	33				(13		)		136				—			156

	Tax	(13		)		1				(55		)		—			(67		)

	Reclassification adjustments, net of taxes	20			(1)	(12		)	(2)	81			(3)	—			89

	Other comprehensive income (loss), net of taxes	(101		)		52				(1,321		)		(180		)	(1,550		)

	Balance December 31, 2012, net of taxes	(97		)		73				(3,667		)		(991		)	(4,682		)

	Other comprehensive income (loss) before reclassification adjustments, pretax	335				33				3,917				(383		)	3,902

	Tax	(132		)		(23		)		(1,365		)		(100		)	(1,620		)
	Other comprehensive income (loss) before reclassification adjustments, net of taxes	203				10				2,552				(483		)	2,282

	Reclassification adjustments, pretax	42				(39		)		286				—			289

	Tax	(16		)		10				(80		)		—			(86		)

	Reclassification adjustments, net of taxes	26			(1)	(29		)	(2)	206			(3)	—			203

	Other comprehensive income (loss), net of taxes	229				(19		)		2,758				(483		)	2,485

	Balance December 31, 2013, net of taxes	132				54				(909		)	(4)	(1,474		)	(2,197		)

	Other comprehensive income (loss) before reclassification adjustments, pretax	778				48				(3,196		)		(412		)	(2,782		)

	Tax	(285		)		(17		)		1,067				(92		)	673

	Other comprehensive income (loss) before reclassification adjustments, net of taxes	493				31				(2,129		)		(504		)	(2,109		)

	Reclassification adjustments, pretax	(146		)		43				62				—			(41		)

	Tax	51				(17		)		(10		)		—			24

	Reclassification adjustments, net of taxes	(95		)	(1)	26			(2)	52			(3)	—			(17		)

	Other comprehensive income (loss), net of taxes	398				57				(2,077		)		(504		)	(2,126		)

	Balance December 31, 2014, net of taxes	$	530			$	111			$	(2,986	)	(4)	$	(1,978	)	$	(4,323	)


	-1	Relates to foreign currency cash flow hedges that were reclassified from AOCI to Sales.

	(2)	Represents net realized (gains) losses 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 13).

	(4)	Includes pension plan net loss of $(3.5) billion and $(1.7) billion at December 31, 2014 and 2013, respectively, and other postretirement benefit plan net loss of $(228) million and $(80) million at December 31, 2014 and in 2013, respectively, as well as pension plan prior service credit of $473 million and $559 million at December 31, 2014 and 2013, respectively, and other postretirement benefit plan prior service credit of $257 million and $331 million at December 31, 2014 and 2013.

Segment_Reporting_Tables

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Sales of Company's Products	Sales of the Company’s products were as follows:


	Years Ended December 31	2014				2013				2012
	Primary Care and Women’s Health
	Cardiovascular
	Zetia	$	2,650			$	2,658			$	2,567

	Vytorin	1,516				1,643				1,747

	Diabetes
	Januvia	3,931				4,004				4,086

	Janumet	2,071				1,829				1,659

	General Medicine and Women’s Health
	NuvaRing	723				686				623

	Implanon/Nexplanon	502				403				348

	Dulera	460				324				207

	Follistim AQ	412				481				468

	Hospital and Specialty
	Hepatitis
	PegIntron	381				496				653

	Victrelis	153				428				502

	HIV
	Isentress	1,673				1,643				1,515

	Acute Care
	Cancidas	681				660				619

	Invanz	529				488				445

	Noxafil	402				309				258

	Bridion	340				288				261

	Primaxin	329				335				384

	Immunology
	Remicade	2,372				2,271				2,076

	Simponi	689				500				331

	Other
	Cosopt/Trusopt	257				416				444

	Oncology
	Emend	553				507				489

	Temodar	350				708				917

	Keytruda	55				—				—

	Diversified Brands
	Respiratory
	Nasonex	1,099				1,335				1,268

	Singulair	1,092				1,196				3,853

Clarinex	232				235				393

Other
Cozaar/Hyzaar	806				1,006				1,284

Arcoxia	519				484				453

Fosamax	470				560				676

Propecia	264				283				424

Zocor	258				301				383

Remeron	193				206				232

Vaccines *(1)*
Gardasil	1,738				1,831				1,631

ProQuad/M-M-R II/Varivax	1,394				1,306				1,273

Zostavax	765				758				651

Pneumovax 23	746				653				580

RotaTeq	659				636				601

Other pharmaceutical (2)	4,778				5,570				6,300

Total Pharmaceutical segment sales	36,042				37,437				40,601

Other segment sales (3)	5,585				6,325				6,412

Total segment sales	41,627				43,762				47,013

Other (4)	610				271				254

	$	42,237			$	44,033			$	47,267


(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 and Alliances, as well as Consumer Care until its divestiture on October 1, 2014 (see Note 4). The Alliances segment includes revenue from the Company’s relationship with AZLP until termination on June 30, 2014 (see Note 8).

(4)	Other revenues are primarily comprised of miscellaneous corporate revenues, including revenue hedging activities, sales related to divested products or businesses, and other supply sales not included in segment results. Other revenues in 2014 include $232 million received by Merck in connection with the sale of the U.S. marketing rights to Saphris (see Note 4). Other revenues in 2013 reflect $50 million of revenue for the out-license of a pipeline compound. Other revenues also include third-party manufacturing sales, a substantial portion of which was divested in October 2013 (see Note 3).
Consolidated Revenues by Geographic Area	Consolidated revenues by geographic area where derived are as follows:


	Years Ended December 31	2014				2013				2012
	United States	$	17,071			$	18,246			$	20,392

	Europe, Middle East and Africa	13,174				13,140				12,990

	Asia Pacific	3,951				3,845				3,775

	Japan	3,471				4,044				5,102

	Latin America	3,151				3,203				3,389

	Other	1,419				1,555				1,619

		$	42,237			$	44,033			$	47,267

Reconciliation of Segment Profits to Income Before Taxes	A reconciliation of total segment profits to consolidated Income before taxes is as follows:


	Years Ended December 31	2014				2013				2012
	Segment profits:
	Pharmaceutical segment	$	22,164			$	22,983			$	25,852

	Other segments	2,546				3,094				3,163

	Total segment profits	24,710				26,077				29,015

	Other profits	539				19				26

	Unallocated:
	Interest income	266				264				232

	Interest expense	(732		)		(801		)		(714		)
	Equity income from affiliates	59				(159		)		102

	Depreciation and amortization	(2,457		)		(2,250		)		(2,059		)
	Research and development	(5,837		)		(6,381		)		(7,126		)
	Amortization of purchase accounting adjustments	(4,182		)		(4,690		)		(4,872		)
	Restructuring costs	(1,013		)		(1,709		)		(664		)
	Gain on divestiture of Merck Consumer Care	11,209				—				—

	Gain on AstraZeneca option exercise	741				—				—

	Gain on the divestiture of certain ophthalmic products	480				—				—

	Loss on extinguishment of debt	(628		)		—				—

	Net charge related to settlement of ENHANCE Litigation	—				—				(493		)

	Other unallocated, net	(5,872		)		(4,825		)		(4,708		)
		$	17,283			$	5,545			$	8,739

Equity Income from Affiliates and Depreciation and Amortization Included in Segment Profits	Equity income from affiliates and depreciation and amortization included in segment profits is as follows:


		Pharmaceutical				All Other				Total
	Year Ended December 31, 2014
	Included in segment profits:
	Equity income from affiliates	$	90			$	108			$	198

	Depreciation and amortization	(39		)		(13		)		(52		)
	Year Ended December 31, 2013
	Included in segment profits:
	Equity income from affiliates	$	88			$	475			$	563

	Depreciation and amortization	(27		)		(22		)		(49		)
	Year Ended December 31, 2012
	Included in segment profits:
	Equity income from affiliates	$	36			$	504			$	540

	Depreciation and amortization	(25		)		(20		)		(45		)
Property, Plant and Equipment, Net by Geographic Area	Property, plant and equipment, net by geographic area where located is as follows:


	Years Ended December 31	2014				2013				2012
	United States	$	8,727			$	10,076			$	10,687

	Europe, Middle East and Africa	3,120				3,346				3,688

	Asia Pacific	897				1,001				1,059

	Latin America	207				242				250

	Japan	172				211				243

	Other	13				97				103

		$	13,136			$	14,973			$	16,030

Nature_of_Operations_Nature_of

Nature of Operations Nature of Operations (Details)	12 Months Ended
	Dec. 31, 2014
	segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segments	3
Number of reportable segments	1

Summary_of_Accounting_Policies2

Summary of Accounting Policies - Textual (Details) (USD $)	12 Months Ended
Summary of Accounting Policies - Textual (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary Of Significant Accounting Policies [Line Items]
Accrual for chargebacks reflected as direct reduction to Accounts receivable	$112,000,000	$87,000,000
Accrual for rebates included in Accrued and other current liabilities	2,000,000,000	1,600,000,000
Depreciation expense	2,500,000,000	2,200,000,000	2,000,000,000
Advertising expenses	2,300,000,000	2,500,000,000	2,800,000,000
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	20 years
Enterprise wide resource planning system [Member]
Summary Of Significant Accounting Policies [Line Items]
Unamortized capitalized software costs	$505,000,000	$548,000,000
Enterprise wide resource planning system [Member] \| Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	6 years
Enterprise wide resource planning system [Member] \| Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	10 years
Capitalized Software [Member] \| Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	3 years
Capitalized Software [Member] \| Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of intangible assets	5 years
Machinery and Equipment [Member] \| Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment	3 years
Machinery and Equipment [Member] \| Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment	15 years
Building [Member] \| Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment	10 years
Building [Member] \| Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life of property, plant and equipment	50 years

Restructuring_Textual_Details

Restructuring - Textual (Details) (USD $)	0 Months Ended	12 Months Ended			1 Months Ended		3 Months Ended
	Oct. 01, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 31, 2013	Jan. 31, 2014	Dec. 31, 2013
	Oct. 01, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	position	Jan. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		$1,978,000,000	$2,401,000,000	$999,000,000
Disposition of Business Agreement Term	5 years
Disposal Group, Including Discontinued Operation, Intangible Assets		2,200,000,000
2013 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Total number of positions expected to be eliminated					8,500
Restructuring and Related Cost, Incurred Cost		1,248,000,000	1,241,000,000
Cumulative restructuring costs incurred to date since program inception		2,500,000,000
Positions eliminated since inception of program		6,095
Expected cumulative restructuring costs, pretax		3,000,000,000
Percentage estimate of cumulative pretax costs that will result in cash outlays (primarily from employee separation expense)		66.67%
Percentage estimate of cumulative pretax costs that will be non-cash (primarily from accelerated depreciation of facilities)		33.33%
Number of positions eliminated		4,555	1,540
Merger Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		730,000,000	1,106,000,000	951,000,000
Cumulative restructuring costs incurred to date since program inception		7,900,000,000
Positions eliminated since inception of program		28,410
Expected cumulative restructuring costs, pretax		8,500,000,000
Percentage estimate of cumulative pretax costs that will result in cash outlays (primarily from employee separation expense)		66.67%
Percentage estimate of cumulative pretax costs that will be non-cash (primarily from accelerated depreciation of facilities)		33.33%
Remaining position eliminations expected		3,440
Number of positions eliminated		1,530	4,475	3,975
Merger Restructuring Program [Member] \| API Manufacturing Business [Member]
Restructuring Cost and Reserve [Line Items]
Total number of positions expected to be eliminated	960
Restructuring and Related Cost, Incurred Cost			65,000,000
Proceeds from divestiture of businesses	705,000,000					533,000,000	172,000,000
Noncash or Part Noncash Divestiture, Amount of Consideration Received	198,000,000
Disposal Group, Including Discontinued Operation, Inventory	420,000,000
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment	220,000,000
Disposal Group, Including Discontinued Operation, Consideration, Cash	125,000,000
Disposal Group, Including Discontinued Operation, Goodwill	45,000,000
Disposal Group, Including Discontinued Operation, Intangible Assets	45,000,000
Disposal Group, Including Discontinued Operation, Other Assets	23,000,000
Other Accrued Liabilities, Current	90,000,000
Merger Restructuring Program [Member] \| API Manufacturing Business [Member] \| Due 2023 [Member]
Restructuring Cost and Reserve [Line Items]
Noncash or Part Noncash Divestiture, Amount of Consideration Received	138,000,000
Financing receivable, gross	261,000,000
Merger Restructuring Program [Member] \| API Manufacturing Business [Member] \| Due Over Five Years [Member]
Restructuring Cost and Reserve [Line Items]
Noncash or Part Noncash Divestiture, Amount of Consideration Received	60,000,000
Financing receivable, gross	67,500,000
2008 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost			54,000,000	48,000,000
Asset abandonment, shut-down and other related costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost		240,000,000	259,000,000	155,000,000
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Pretax gains (losses) resulting from sales of facilities		($133,000,000)	($64,000,000)	$28,000,000

Restructuring_Charges_Related_

Restructuring - Charges Related to Restructuring Program Activities by Type of Cost (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Materials and production	$16,768	$16,954	$16,446
Marketing and administrative	11,606	11,911	12,776
Research and development	7,180	7,503	8,168
Restructuring costs	1,013	1,709	664
Expenses	1,978	2,401	999
2013 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	227	193
Marketing and administrative	145	75
Research and development	282	75
Restructuring costs	594	898
Expenses	1,248	1,241
Merger Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	255	249	162
Marketing and administrative	55	66	81
Research and development	1	26	57
Restructuring costs	419	765	651
Expenses	730	1,106	951
2008 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production		4	26
Marketing and administrative		4	9
Restructuring costs		46	13
Expenses		54	48
Separation Costs [Member]
Restructuring Cost and Reserve [Line Items]
Expenses	674	1,381	489
Separation Costs [Member] \| 2013 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	0	0
Marketing and administrative	0	0
Research and development	0	0
Restructuring costs	566	866
Expenses	566	866
Separation Costs [Member] \| Merger Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	0	0	0
Marketing and administrative	0	0	0
Research and development	0	0	0
Restructuring costs	108	481	497
Expenses	108	481	497
Separation Costs [Member] \| 2008 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production		0	0
Marketing and administrative		0	0
Restructuring costs		34	-8
Expenses		34	-8
Accelerated Depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Expenses	900	577	235
Accelerated Depreciation [Member] \| 2013 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	204	186
Marketing and administrative	142	72
Research and development	273	76
Restructuring costs	0	0
Expenses	619	334
Accelerated Depreciation [Member] \| Merger Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	225	151	92
Marketing and administrative	56	63	75
Research and development	0	27	53
Restructuring costs	0	0	0
Expenses	281	241	220
Accelerated Depreciation [Member] \| 2008 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production		-2	7
Marketing and administrative		4	8
Restructuring costs		0	0
Expenses		2	15
Other [Member]
Restructuring Cost and Reserve [Line Items]
Expenses	404	443	275
Other [Member] \| 2013 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	23	7
Marketing and administrative	3	3
Research and development	9	-1
Restructuring costs	28	32
Expenses	63	41
Other [Member] \| Merger Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production	30	98	70
Marketing and administrative	-1	3	6
Research and development	1	-1	4
Restructuring costs	311	284	154
Expenses	341	384	234
Other [Member] \| 2008 Restructuring Program [Member]
Restructuring Cost and Reserve [Line Items]
Materials and production		6	19
Marketing and administrative		0	1
Restructuring costs		12	21
Expenses		$18	$41

Restructuring_Charges_and_Spen

Restructuring - Charges and Spending Relating to Restructuring Activities by Program (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Restructuring Reserve [Roll Forward]
Expenses	$1,978		$2,401	$999
2013 Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	768		0
Expenses	1,248		1,241
(Payments) receipts, net	-940		-112
Non-cash activity	-567		-361
Restructuring reserve, ending balance	509	[1]	768
Merger Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	737		718
Expenses	730		1,106	951
(Payments) receipts, net	-529		-775
Non-cash activity	-396		-312
Restructuring reserve, ending balance	542	[1]	737	718
Separation Costs [Member]
Restructuring Reserve [Roll Forward]
Expenses	674		1,381	489
Separation Costs [Member] \| 2013 Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	745		0
Expenses	566		866
(Payments) receipts, net	-816		-121
Non-cash activity	0		0
Restructuring reserve, ending balance	495	[1]	745
Separation Costs [Member] \| Merger Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	725		699
Expenses	108		481	497
(Payments) receipts, net	-297		-517
Non-cash activity	0		62
Restructuring reserve, ending balance	536	[1]	725	699
Accelerated Depreciation [Member]
Restructuring Reserve [Roll Forward]
Expenses	900		577	235
Accelerated Depreciation [Member] \| 2013 Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	0		0
Expenses	619		334
(Payments) receipts, net	0		0
Non-cash activity	-619		-334
Restructuring reserve, ending balance	0	[1]	0
Accelerated Depreciation [Member] \| Merger Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	0		0
Expenses	281		241	220
(Payments) receipts, net	0		0
Non-cash activity	-281		-241
Restructuring reserve, ending balance	0	[1]	0	0
Other [Member]
Restructuring Reserve [Roll Forward]
Expenses	404		443	275
Other [Member] \| 2013 Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	23		0
Expenses	63		41
(Payments) receipts, net	-124		9
Non-cash activity	52		-27
Restructuring reserve, ending balance	14	[1]	23
Other [Member] \| Merger Restructuring Program [Member]
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	12		19
Expenses	341		384	234
(Payments) receipts, net	-232		-258
Non-cash activity	-115		-133
Restructuring reserve, ending balance	$6	[1]	$12	$19

[1]	The cash outlays associated with the 2013 Restructuring Program are expected to be substantially completed by the end of 2015. The non-manufacturing cash outlays associated with the Merger Restructuring Program were substantially completed by the end of 2013; the remaining cash outlays are expected to be substantially completed by the end of 2016.

Acquisitions_Divestitures_Rese1

Acquisitions, Divestitures, Research Collaborations and License Agreements - Textual (Details) (USD $)

0 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

0 Months Ended

1 Months Ended

3 Months Ended

1 Months Ended

3 Months Ended

1 Months Ended

In Millions, except Share data, unless otherwise specified

Oct. 01, 2013

Oct. 06, 2009

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Oct. 01, 2014

Jan. 21, 2015

Dec. 31, 2014

Sep. 30, 2014

Aug. 31, 2014

Jul. 01, 2014

31-May-14

Mar. 31, 2014

Jun. 30, 2014

Mar. 31, 2014

Apr. 30, 2013

Dec. 31, 2013

Sep. 30, 2013

Feb. 28, 2013

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Contingent consideration

$428

$69

$49

$428

$69

Proceeds from divestiture of business, net

13,951

Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal

11,209

Payments to Acquire Intangible Assets

1,000

Payments to Acquire Businesses, Net of Cash Acquired

181

246

Goodwill

12,992

[1]

12,301

12,134

12,992

[1]

12,301

Disposition of Business Agreement Term

5 years

Income Tax Benefit

-5,349

-1,028

-2,440

In-process research and development impairment charges

279

200

Goodwill, Impairment Loss

Extended marketing rights for both products (Remicade and Simponi)

15 years

Minimum [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Estimated useful life of intangible assets

3 years

Maximum [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Estimated useful life of intangible assets

20 years

Adempas [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Estimated useful life of intangible assets

12 years

Consumer Care [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Proceeds from divestiture of businesses

14,200

Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal

11,200

Cubist [Member] | Subsequent Event [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Business Combination, Consideration Transferred

9,500

OncoEthix [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Business Combination, Consideration Transferred

153

Payments to Acquire Businesses, Gross

110

Potential future milestone payments

265

Contingent consideration

Business acquisition, assets acquired and liabilities assumed, IPR&D

143

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net

Fair Value Inputs, Discount Rate

11.50%

Bayer AG [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Payments to Acquire Intangible Assets

1,000

Business combination, recognized identifiable assets acquired and liabilities assumed, finite-lived intangibles

915

Research and Development in Process

Bayer AG [Member] | Adempas [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Fair Value Inputs, Discount Rate

10.00%

Bayer AG [Member] | vericiguat [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Fair Value Inputs, Discount Rate

10.50%

Sun Pharma [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Proceeds from collaborators

Loss on Disposition of Intangible Assets

Idenix Pharmaceuticals, Inc. [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Business Combination, Consideration Transferred

3,900

Business acquisition, assets acquired and liabilities assumed, IPR&D

3,200

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net

Fair Value Inputs, Discount Rate

11.50%

Payments to Acquire Businesses, Net of Cash Acquired

3,700

Business acquisition, assets acquired and liabilities assumed, deferred tax liabilities

856

Goodwill

1,400

Santen Pharmaceutical Co. Ltd. [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Proceeds from divestiture of businesses

515

Gain (Loss) on Disposition of Business

480

Santen Pharmaceutical Co. Ltd. [Member] | Minimum [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Disposition of Business Agreement Term

2 years

Santen Pharmaceutical Co. Ltd. [Member] | Maximum [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Disposition of Business Agreement Term

5 years

Sirna Therapeutics Inc. [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Proceeds from Sale of Other Assets

Shares received in consideration for sale of asset

2,520,044

Percentage Shares Received From Sale of Technology

15.00%

85.00%

Noncash or Part Noncash Divestiture, Amount of Consideration Received

172

Gain (Loss) on Disposition of Other Assets

204

Income Tax Benefit

300

Forest Laboratories Inc [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Proceeds from Sale of Intangible Assets

232

Merck & Co., Inc [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Revenue and cost allocation percentage

60.00%

Pfizer Inc [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Expenses for upfront and milestone payments made to collaborative partner

125

Revenue and cost allocation percentage

40.00%

Length of time to give notice to terminate the agreement

12 months

Supera [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Business acquisition, assets acquired and liabilities assumed, IPR&D

100

Business combination, recognized identifiable assets acquired and liabilities assumed, finite-lived intangibles

Business acquisition, assets acquired and liabilities assumed, deferred tax liabilities

Goodwill

103

Controlling interest ownership of the joint venture, percentage

51.00%

Noncontrolling interest ownership of the joint venture, percentage

49.00%

Increase in noncontrolling interests

112

Increase in other paid-in-capital

116

In-process research and development impairment charges

Goodwill, Impairment Loss

AstraZeneca [Member]

Acquisitions Divestitures Research Collaborations And License Agreements Transactions [Line Items]

Proceeds from collaborators

$50

[1]

Accumulated goodwill impairment losses at December 31, 2014 were $93 million.

Financial_Instruments_Textual_

Financial Instruments - Textual (Details) (USD $)	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Feb. 28, 2015	Dec. 31, 2011	Oct. 31, 2014
	interest_rate_swap	Dec. 31, 2013	Dec. 31, 2012	interest_rate_swap	Dec. 31, 2011	Oct. 31, 2014
Derivative [Line Items]
Maximum planning cycle of third-party sales hedges (no more than)	3 years
Pretax gains (losses) from euro-denominated notes included in cumulative translation adjustments	$294,000,000	($84,000,000)	($31,000,000)
Number of interest rate derivatives held	17
Derivative, notional amount	26,068,000,000	29,909,000,000
Cash received on termination of interest rate swaps	3,000,000
Pre tax net unrealized gain (loss) on derivatives maturing within next 12 months estimated to be reclassified from AOCI to sales	457,000,000
Available-for-sale debt securities included in Short-term investments	8,300,000,000
Available-for-sale debt securities maturing after one year through five years	12,000,000,000
Cash and cash equivalents	7,441,000,000	15,621,000,000	13,451,000,000		13,531,000,000
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	316,000,000	8,000,000
Contingent consideration	428,000,000	69,000,000	49,000,000
Fair value of loans payable and long-term debt, including current portion	22,500,000,000	25,500,000,000
Carrying value of Loans payable and long-term debt, including current portion	21,400,000,000	25,100,000,000
Maximum average period of maturities of contracts in years	1 year
Noncurrent accounts receivable	80,000,000	275,000,000
Total accounts receivable outstanding in excess of one year	100,000,000
Percentage of accounts receivable outstanding for more than one year that relate to Greece, Italy, Spain and Portugal	31.00%
Percentage of accounts receivable represented by customers with largest balances	30.00%
Cash collateral received from counterparties	1,410,000,000	652,000,000
Greece, Italy, Spain and Portugal [Member]
Derivative [Line Items]
Accounts receivable in Greece, Italy, Spain and Portugal	600,000,000
Greece, Italy, Spain and Portugal [Member] \| Hospital and public sector [Member]
Derivative [Line Items]
Accounts receivable in Greece, Italy, Spain and Portugal	330,000,000
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	14.00%
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	27.00%
Receivables factored during period	100,000,000		230,000,000
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	46.00%
Receivables factored during period	100,000,000	210,000,000
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	13.00%
Spanish government's debt stabilization/stimulus plan [Member]
Derivative [Line Items]
Accounts receivable collected			500,000,000
OncoEthix [Member]
Derivative [Line Items]
Contingent consideration	43,000,000
Significant Other Observable Inputs (Level 2) [Member]
Derivative [Line Items]
Cash and cash equivalents	7,400,000,000
Cash equivalents	6,100,000,000
Subsequent Event [Member]
Derivative [Line Items]
Derivative, notional amount				$250,000,000
Number of interest rate swaps entered into				10
6.00% Notes Due 2017 [Member]
Derivative [Line Items]
Fixed-rate notes, stated interest rate	6.00%					6.00%
1.85% Notes Due 2020 [Member] \| Subsequent Event [Member]
Derivative [Line Items]
Fixed-rate notes, stated interest rate				1.85%
2.35% Notes Due 2022 [Member] \| Subsequent Event [Member]
Derivative [Line Items]
Fixed-rate notes, stated interest rate				2.35%

Financial_Instruments_Financia

Financial Instruments Financial Instruments - Information About Interest Rate Swaps (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
	interest_rate_swap	Dec. 31, 2013
Derivative [Line Items]
Number of interest rate derivatives held	17
Derivative, notional amount	$26,068,000,000	$29,909,000,000
0.70% notes due 2016 [Member]
Derivative [Line Items]
Fixed-rate notes, stated interest rate	0.70%
0.70% notes due 2016 [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Debt Instrument, Face Amount	1,000,000,000
Number of interest rate derivatives held	4
Derivative, notional amount	1,000,000,000
Fixed-rate notes, stated interest rate	0.70%
1.30% notes due 2018 [Member]
Derivative [Line Items]
Fixed-rate notes, stated interest rate	1.30%
1.30% notes due 2018 [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Debt Instrument, Face Amount	1,000,000,000
Number of interest rate derivatives held	4
Derivative, notional amount	1,000,000,000
Fixed-rate notes, stated interest rate	1.30%
5.00% Notes Due 2019 [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Debt Instrument, Face Amount	1,250,000,000
Number of interest rate derivatives held	3
Derivative, notional amount	550,000,000
Fixed-rate notes, stated interest rate	5.00%
3.875% notes due 2021 [Member]
Derivative [Line Items]
Fixed-rate notes, stated interest rate	3.88%
3.875% notes due 2021 [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Debt Instrument, Face Amount	1,150,000,000
Number of interest rate derivatives held	5
Derivative, notional amount	1,150,000,000
Fixed-rate notes, stated interest rate	3.88%
2.40% notes due 2022 [Member]
Derivative [Line Items]
Fixed-rate notes, stated interest rate	2.40%
2.40% notes due 2022 [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Debt Instrument, Face Amount	1,000,000,000
Number of interest rate derivatives held	1
Derivative, notional amount	$250,000,000
Fixed-rate notes, stated interest rate	2.40%

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 (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Fair value of derivative, Asset	$1,847	$1,090
Fair value of derivative, Liability	103	184
U.S. Dollar Notional	26,068	29,909
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative, Asset	1,482	1,021
Fair value of derivative, Liability	15	44
U.S. Dollar Notional	15,716	16,312
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative, Asset	365	69
Fair value of derivative, Liability	88	140
U.S. Dollar Notional	10,352	13,597
Interest Rate Swap [Member] \| Derivatives Designated as Hedging Instruments [Member] \| Other assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative, Asset	19	13
U.S. Dollar Notional	1,950	1,550
Interest Rate Swap [Member] \| Derivatives Designated as Hedging Instruments [Member] \| Other noncurrent liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative, Liability	15	25
U.S. Dollar Notional	2,000	2,000
Foreign exchange contract [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	772	493
U.S. Dollar Notional	5,513	4,427
Foreign exchange contract [Member] \| Derivatives Designated as Hedging Instruments [Member] \| Other assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative, Asset	691	515
Fair value of derivative, Liability
U.S. Dollar Notional	6,253	6,676
Foreign exchange contract [Member] \| Derivatives Designated as Hedging Instruments [Member] \| Accrued and other current liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative, Liability	0	19
U.S. Dollar Notional	0	1,659
Foreign exchange contract [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	365	69
U.S. Dollar Notional	6,966	5,705
Foreign exchange contract [Member] \| Derivatives Not Designated as Hedging Instruments [Member] \| Accrued and other current liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of derivative, Liability	88	140
U.S. Dollar Notional	$3,386	$7,892

Financial_Instruments_Informat

Financial Instruments - Information on Derivative Positions Subject to Master Netting Arrangements as if they were Presented on a Net Basis (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative assets	$1,847	$1,090
Gross amount subject to offset in master netting arrangements not offset in the consolidated balance sheet, Asset	-97	-147
Cash collateral (received) posted, Asset	-1,410	-652
Net amounts, Asset	340	291
Derivative liabilities	103	184
Gross amount subject to offset in master netting arrangements not offset in the consolidated balance sheet, Liability	-97	-147
Cash collateral (received) posted, Liability	0	0
Net amounts, Liability	$6	$37

Financial_Instruments_Location

Financial Instruments - Location and Pretax Gain or Loss Amounts for Derivatives (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Ineffectiveness on the hedged item	$3		$2
Derivatives not designated in a hedging relationship [Member] \| Foreign exchange contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (gain) loss recognized in Other (income) expense, net on derivatives	-516	[1]	183	[1]	382	[1]
Amount of loss recognized in Sales	15		8		30
Derivatives designated in fair value hedging relationships [Member] \| Interest rate swap contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (gain) loss recognized in Other (income) expense, net on derivatives	-17	[2]	12	[2]	0	[2]
Amount of loss (gain) recognized in Other (income) expense, net on hedged item	14	[2]	-14	[2]	0	[2]
Derivatives designated in foreign currency cash flow hedging relationships [Member] \| Foreign exchange contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (gain) loss reclassified from AOCI to Sales	-143		45		50
Amount of (gain) loss recognized in OCI on derivatives	-775		-306		204
Derivatives designated in foreign currency net investment hedging relationships [Member] \| Foreign exchange contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of (gain) loss recognized in OCI on derivatives	-192		-363		-208
Amount of gain recognized in Other (income) expense, net on derivatives	($6)	[3]	($10)	[3]	($20)	[3]

[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 $3 million and $2 million of ineffectiveness on the hedge during 2014 and 2013, respectively.
[3]	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 (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$22,028	$11,868
Amortized Cost	21,855	11,787
Gross Unrealized Gains	199	110
Gross Unrealized Losses	-26	-29
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	6,970	1,206
Amortized Cost	6,970	1,206
Corporate notes and bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	10,107	7,054
Amortized Cost	10,102	7,037
Gross Unrealized Gains	22	32
Gross Unrealized Losses	-17	-15
U.S. government and agency securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	1,774	1,236
Amortized Cost	1,775	1,239
Gross Unrealized Gains	1	1
Gross Unrealized Losses	-2	-4
Asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	1,460	1,300
Amortized Cost	1,462	1,303
Gross Unrealized Gains	1	1
Gross Unrealized Losses	-3	-4
Mortgage-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	602	476
Amortized Cost	604	479
Gross Unrealized Gains	2	2
Gross Unrealized Losses	-4	-5
Foreign government bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	385	125
Amortized Cost	385	126
Gross Unrealized Gains	0	0
Gross Unrealized Losses		-1
Equity securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	730	471
Amortized Cost	557	397
Gross Unrealized Gains	$173	$74

Financial_Instruments_Financia1

Financial Instruments - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Assets
Fair Value	$22,028		$11,868
Derivative assets	1,847		1,090
Liabilities
Contingent consideration	428		69		49
Derivative liabilities	103		184
Commercial paper [Member]
Assets
Fair Value	6,970		1,206
Corporate notes and bonds [Member]
Assets
Fair Value	10,107		7,054
U.S. government and agency securities [Member]
Assets
Fair Value	1,774		1,236
Asset-backed securities [Member]
Assets
Fair Value	1,460		1,300
Liabilities
Primary weighted-average lives of investment collateral	5 years
Mortgage-backed securities [Member]
Assets
Fair Value	602		476
Foreign government bonds [Member]
Assets
Fair Value	385		125
Equity securities [Member]
Assets
Fair Value	730		471
Fair Value, Measurements, Recurring [Member]
Assets
Investments	21,793		11,635
Securities held for employee compensation	235		233
Purchased currency options	1,252	[1]	868	[1]
Derivative assets	1,847	[1]	1,090	[1]
Total assets	23,875		12,958
Liabilities
Contingent consideration	428		69
Derivative liabilities	103	[1]	184	[1]
Total liabilities	531		253
Fair Value, Measurements, Recurring [Member] \| Foreign exchange contract [Member]
Assets
Derivative assets	576	[1]	209	[1]
Liabilities
Derivative liabilities	46	[1]	134	[1]
Fair Value, Measurements, Recurring [Member] \| Interest rate swap contract [Member]
Assets
Derivative assets	19	[1]	13	[1]
Liabilities
Derivative liabilities	15	[1]	25	[1]
Fair Value, Measurements, Recurring [Member] \| Written currency options [Member]
Liabilities
Derivative liabilities	42	[1]	25	[1]
Fair Value, Measurements, Recurring [Member] \| Commercial paper [Member]
Assets
Fair Value	6,970		1,206
Fair Value, Measurements, Recurring [Member] \| Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Assets
Investments	495		238
Securities held for employee compensation	181		186
Total assets	676		424
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Assets
Investments	21,298		11,397
Securities held for employee compensation	54		47
Purchased currency options	1,252	[1]	868	[1]
Derivative assets	1,847	[1]	1,090	[1]
Total assets	23,199		12,534
Liabilities
Derivative liabilities	103	[1]	184	[1]
Total liabilities	103		184
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Foreign exchange contract [Member]
Assets
Derivative assets	576	[1]	209	[1]
Liabilities
Derivative liabilities	46	[1]	134	[1]
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Interest rate swap contract [Member]
Assets
Derivative assets	19	[1]	13	[1]
Liabilities
Derivative liabilities	15	[1]	25	[1]
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Written currency options [Member]
Liabilities
Derivative liabilities	42	[1]	25	[1]
Fair Value, Measurements, Recurring [Member] \| Significant Other Observable Inputs (Level 2) [Member] \| Commercial paper [Member]
Assets
Fair Value	6,970		1,206
Fair Value, Measurements, Recurring [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Liabilities
Contingent consideration	428		69
Total liabilities	428		69
Fair Value, Measurements, Recurring [Member] \| Corporate notes and bonds [Member]
Assets
Fair Value	10,107		7,054
Fair Value, Measurements, Recurring [Member] \| Corporate notes and bonds [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Assets
Fair Value	10,107		7,054
Fair Value, Measurements, Recurring [Member] \| U.S. government and agency securities [Member]
Assets
Fair Value	1,774		1,236
Fair Value, Measurements, Recurring [Member] \| U.S. government and agency securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Assets
Fair Value	1,774		1,236
Fair Value, Measurements, Recurring [Member] \| Asset-backed securities [Member]
Assets
Fair Value	1,460	[2]	1,300	[2]
Fair Value, Measurements, Recurring [Member] \| Asset-backed securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Assets
Fair Value	1,460	[2]	1,300	[2]
Fair Value, Measurements, Recurring [Member] \| Mortgage-backed securities [Member]
Assets
Fair Value	602	[2]	476	[2]
Fair Value, Measurements, Recurring [Member] \| Mortgage-backed securities [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Assets
Fair Value	602	[2]	476	[2]
Fair Value, Measurements, Recurring [Member] \| Foreign government bonds [Member]
Assets
Fair Value	385		125
Fair Value, Measurements, Recurring [Member] \| Foreign government bonds [Member] \| Significant Other Observable Inputs (Level 2) [Member]
Assets
Fair Value	385		125
Fair Value, Measurements, Recurring [Member] \| Equity securities [Member]
Assets
Fair Value	495		238
Fair Value, Measurements, Recurring [Member] \| Equity securities [Member] \| Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Assets
Fair Value	$495		$238

[1]	The fair value determination of derivatives includes the impact of the credit risk of counterparties to the derivatives and the Companyâ€™s own credit risk, the effects of which were not significant.
[2]	Primarily all of the asset-backed securities are highly-rated (StandardÂ & Poorâ€™s rating of AAA and Moodyâ€™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.

Financial_Instruments_Financia2

Financial Instruments Financial Instruments - Summarized Information About Changes in Liabilities for Contingent Consideration (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Contingent consideration	$69	$49
Changes in fair value (recorded in Research and development expenses)	316	8
Additions	43	12
Contingent consideration	$428	$69

Inventories_Inventories_Detail

Inventories - Inventories (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Inventory Disclosure [Abstract]
Finished goods	$1,588	$1,738
Raw materials and work in process	5,141	5,894
Supplies	197	225
Total (approximates current cost)	6,926	7,857
Increase to LIFO costs	309	73
Total current and noncurrent inventories	7,235	7,930
Recognized as:
Inventories	5,571	6,226
Other assets	$1,664	$1,704

Inventories_Textual_Detail

Inventories - Textual (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Inventory Disclosure [Abstract]
LIFO Inventory Amount	$2,600,000,000	$2,300,000,000
Inventories not expected to be sold within one year included in Other assets	1,600,000,000	1,500,000,000
Inventories produced in preparation for product launches included in Other Assets	$74,000,000	$177,000,000

Goodwill_and_Other_Intangibles2

Goodwill and Other Intangibles - Goodwill Activity by Segment (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$12,301		$12,134
Acquisitions	1,407		291
Divestitures	-562		-45
Impairments	-93
Other	-61	[1]	-79	[1]
Goodwill, Ending Balance	12,992	[2]	12,301
Goodwill, Impaired, Accumulated Impairment Loss	93
Pharmaceutical [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	10,065		10,086
Acquisitions	1,369		103
Divestitures	-200		-45
Impairments	-93
Other	-33	[1]	-79	[1]
Goodwill, Ending Balance	11,108	[2]	10,065
All Other [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	2,236		2,048
Acquisitions	38		188
Divestitures	-362		0
Impairments	0
Other	-28	[1]	0	[1]
Goodwill, Ending Balance	$1,884	[2]	$2,236

[1]	Other includes cumulative translation adjustments on goodwill balances and certain other adjustments.
[2]	Accumulated goodwill impairment losses at December 31, 2014 were $93 million.

Goodwill_and_Other_Intangibles3

Goodwill and Other Intangibles - Other Intangibles (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	$44,784	$46,137
Accumulated Amortization	24,398	22,336
Net	20,386	23,801
Products and product rights [Member]
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	38,714	41,691
Accumulated Amortization	23,830	21,216
Net	14,884	20,475
In-process research and development [Member]
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	4,345	1,856
Net	4,345	1,856
Tradenames [Member]
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	198	1,632
Accumulated Amortization	71	310
Net	127	1,322
Other [Member]
Intangible Assets Excluding Goodwill [Line Items]
Gross Carrying Amount	1,527	958
Accumulated Amortization	497	810
Net	$1,030	$148

Goodwill_and_Other_Intangibles4

Goodwill and Other Intangibles - Textual (Details) (USD $)	12 Months Ended			1 Months Ended
Goodwill and Other Intangibles - Textual (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 31, 2014	Jul. 31, 2013	Nov. 30, 2013
Intangible Assets Excluding Goodwill [Line Items]
Acquisitions	$1,407,000,000	$291,000,000
Other Intangibles, Net	20,386,000,000	23,801,000,000
Disposal Group, Including Discontinued Operation, Intangible Assets	2,200,000,000
Intangible asset impairment charge related to marketed product	1,100,000,000	486,000,000
IPR&D reclassified to products and product rights upon receipt of marketing approval	654,000,000	346,000,000	78,000,000
In-process research and development impairment charges	49,000,000	279,000,000	200,000,000
Amortization expense for intangible assets	4,200,000,000	4,800,000,000	5,000,000,000
Estimated Future Amortization Expense, 2015	3,900,000,000
Estimated Future Amortization Expense, 2016	3,200,000,000
Estimated Future Amortization Expense, 2017	2,900,000,000
Estimated Future Amortization Expense, 2018	1,400,000,000
Estimated Future Amortization Expense, 2019	638,000,000
Idenix Pharmaceuticals, Inc. [Member]
Intangible Assets Excluding Goodwill [Line Items]
Business Combination, Consideration Transferred				3,900,000,000
Business acquisition, assets acquired and liabilities assumed, IPR&D				3,200,000,000
Zetia [Member]
Intangible Assets Excluding Goodwill [Line Items]
Other Intangibles, Net	3,600,000,000
Vytorin [Member]
Intangible Assets Excluding Goodwill [Line Items]
Other Intangibles, Net	2,100,000,000
Nasonex [Member]
Intangible Assets Excluding Goodwill [Line Items]
Other Intangibles, Net	719,000,000
NuvaRing [Member]
Intangible Assets Excluding Goodwill [Line Items]
Other Intangibles, Net	684,000,000
Implanon/Nexplanon [Member]
Intangible Assets Excluding Goodwill [Line Items]
Other Intangibles, Net	703,000,000
Adempas [Member]
Intangible Assets Excluding Goodwill [Line Items]
Other Intangibles, Net	858,000,000
PegIntron [Member]
Intangible Assets Excluding Goodwill [Line Items]
Intangible asset impairment charge related to marketed product	793,000,000
Victrelis [Member]
Intangible Assets Excluding Goodwill [Line Items]
Intangible asset impairment charge related to marketed product	244,000,000
Rebetol [Member]
Intangible Assets Excluding Goodwill [Line Items]
Intangible asset impairment charge related to marketed product	35,000,000	156,000,000
Saphris/Sycrest [Member]
Intangible Assets Excluding Goodwill [Line Items]
Intangible asset impairment charge related to marketed product		330,000,000
Preladenant [Member]
Intangible Assets Excluding Goodwill [Line Items]
In-process research and development impairment charges		181,000,000
Other segments [Member]
Intangible Assets Excluding Goodwill [Line Items]
Acquisitions	38,000,000	188,000,000
Other segments [Member] \| Healthservices and Solutions [Member]
Intangible Assets Excluding Goodwill [Line Items]
Acquisitions		175,000,000
Physicians Interactive [Member]
Intangible Assets Excluding Goodwill [Line Items]
Noncontrolling interest, ownership percentage					24.00%
Business Combination, Consideration Transferred					97,000,000
Health Management Resources Corporation [Member]
Intangible Assets Excluding Goodwill [Line Items]
Business Combination, Consideration Transferred						$87,000,000

Joint_Ventures_and_Other_Equit2

Joint Ventures and Other Equity Method Affiliates - Equity Income from Affiliates (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Equity Income from Affiliates [Line Items]
Equity income from affiliates	$257		$404		$642
Other [Member]
Equity Income from Affiliates [Line Items]
Equity income from affiliates	65	[1]	52	[1]	21	[1]
AstraZeneca LP [Member]
Equity Income from Affiliates [Line Items]
Equity income from affiliates	$192	[2]	$352	[2]	$621	[2]

[1]	Includes results from Sanofi Pasteur MSD.
[2]	As noted below, as of July 1, 2014, the Company no longer records equity income from AZLP.

Joint_Ventures_and_Other_Equit3

Joint Ventures and Other Equity Method Affiliates - Textual (Details) (USD $)	12 Months Ended				0 Months Ended	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014	Dec. 31, 1998	Dec. 31, 1993
Equity Income from Affiliates [Line Items]
Proceeds from AstraZeneca option exercise	$419,000,000		$0	$0
Recognition of Deferred Revenue	140,000,000
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	2,400,000,000
Goodwill, Written off Related to Sale of Business Unit	562,000,000		45,000,000
Deferred income tax benefit	2,600,000,000		330,000,000	-669,000,000
Investments in affiliates accounted for using the equity method	337,000,000		1,600,000,000
Amounts due from equity method affiliates	45,000,000		277,000,000
AMI [Member]
Equity Income from Affiliates [Line Items]
Percentage of ownership in joint venture							50.00%
AstraZeneca LP [Member]
Equity Income from Affiliates [Line Items]
Limited partner interest in AZLP						1.00%
General partner interest in AZLP						99.00%
Revenue from AZLP	463,000,000		920,000,000	915,000,000
Proceeds from AstraZeneca option exercise					419,000,000
Agreed-upon payment to be made by AstraZeneca at closing for exercise of option					327,000,000
Gain (Loss) on Disposition of Assets	91,000,000
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
Other Noncash Income	650,000,000
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	2,400,000,000
Equity Method Investment, Amount Sold	1,400,000,000
Goodwill, Written off Related to Sale of Business Unit	340,000,000
Deferred income tax benefit	517,000,000
Sales of products marketed by the joint venture	2,205,000,000	[1]	4,611,000,000	4,694,000,000
Sanofi Pasteur MSD [Member]
Equity Income from Affiliates [Line Items]
Sales of products marketed by the joint venture	$1,100,000,000		$1,200,000,000	$1,100,000,000

[1]	Includes results through the June 30, 2014 termination date.

Joint_Ventures_and_Other_Equit4

Joint Ventures and Other Equity Method Affiliates - Summarized Financial Information for AZLP (Details) (AstraZeneca LP [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 1998
AstraZeneca LP [Member]
Equity Income from Affiliates [Line Items]
Sales	$2,205	[1]	$4,611		$4,694
Materials and production costs	1,044	[1]	2,222		2,177
Other expense, net	604	[1]	1,175		1,312
Income before taxes	557	[1],[2]	1,214	[2]	1,205	[2]
Current assets			4,832
Noncurrent assets			182
Current liabilities			$3,958
Limited partner interest in AZLP							1.00%

[1]	Includes results through the June 30, 2014 termination date.
[2]	Merckâ€™s partnership returns from AZLP were generally contractually determined as noted above and were not based on a percentage of income from AZLP, other than with respect to Merckâ€™s 1% limited partnership interest.

Joint_Ventures_and_Other_Equit5

Joint Ventures and Other Equity Method Affiliates - Summarized Financial Information for Affiliates (Excluding AZLP) (Details) (Other [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other [Member]
Equity Income from Affiliates [Line Items]
Sales	$1,370	$1,326	$1,295
Materials and production costs	577	581	573
Other expense, net	641	691	705
Income before taxes	152	54	17
Current assets	1,819	1,486
Noncurrent assets	208	149
Current liabilities	469	456
Noncurrent liabilities	$129	$154

Loans_Payable_LongTerm_Debt_an2

Loans Payable, Long-Term Debt and Other Commitments - Long-Term Debt (Details) (USD $)	Dec. 31, 2014	Oct. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Oct. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-Term Debt	$18,699		$20,539
2.80% notes due 2023 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	2.80%
Long-Term Debt	1,749		1,749
5.00% notes due 2019 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	5.00%
Long-Term Debt	1,291		1,293
4.15% notes due 2043 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	4.15%
Long-Term Debt	1,246		1,246
1.125% euro-denominated notes due 2021 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	1.13%	1.13%
Long-Term Debt	1,218		0
1.875% euro-denominated notes due 2026 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	1.88%	1.88%
Long-Term Debt	1,210		0
3.875% notes due 2021 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	3.88%
Long-Term Debt	1,150		1,148
2.40% notes due 2022 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	2.40%
Long-Term Debt	1,000		1,000
Floating-rate borrowing due 2018 [Member]
Debt Instrument [Line Items]
Long-Term Debt	1,000		1,000
1.10% notes due 2018 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	1.10%
Long-Term Debt	999		998
0.70% notes due 2016 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	0.70%
Long-Term Debt	998		997
1.30% notes due 2018 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	1.30%
Long-Term Debt	984		975
2.25% notes due 2016 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	2.25%
Long-Term Debt	858		866
6.50% notes due 2033 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	6.50%
Long-Term Debt	812		1,306
2.50% euro-denominated notes due 2034 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	2.50%	2.50%
Long-Term Debt	603		0
6.55% notes due 2037 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	6.55%
Long-Term Debt	597		1,143
Floating-rate borrowing due 2016 [Member]
Debt Instrument [Line Items]
Long-Term Debt	500		500
3.60% notes due 2042 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	3.60%
Long-Term Debt	493		492
5.85% notes due 2039 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	5.85%
Long-Term Debt	418		749
5.75% notes due 2036 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	5.75%
Long-Term Debt	371		498
5.95% debentures due 2028 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	5.95%
Long-Term Debt	356		498
6.40% debentures due 2028 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	6.40%
Long-Term Debt	326		499
6.30% debentures due 2026 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	6.30%
Long-Term Debt	152		249
6.00% notes due 2017 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	6.00%
Long-Term Debt	0		1,095
4.00% notes due 2015 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	4.00%	4.00%
Long-Term Debt	0		1,029
4.75% notes due 2015 [Member]
Debt Instrument [Line Items]
Stated interest rate of senior unsecured notes	4.75%
Long-Term Debt	0		1,023
Other [Member]
Debt Instrument [Line Items]
Long-Term Debt	$368		$186

Loans_Payable_LongTerm_Debt_an3

Loans Payable, Long-Term Debt and Other Commitments - Textual (Details)

1 Months Ended

12 Months Ended

Oct. 31, 2014

Aug. 31, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Feb. 28, 2015

Feb. 20, 2015

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Oct. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Oct. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Oct. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Nov. 30, 2014

Oct. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Nov. 30, 2014

Oct. 31, 2014

Feb. 28, 2015

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

USD ($)

Subsequent Event [Member]

Other Variable Rate Debt [Member]

Other Foreign Debt [Member]

6.30% debentures due 2026 [Member]

1.125% Euro Notes Due 2021 [Member]

1.875% Euro Notes Due 2026 [Member]

2.5% Euro Notes Due 2034 [Member]

4.00% notes due 2015 [Member]

6.00% Notes Due 2017 [Member]

Floating Rate Notes Due 2017 [Member]

Floating Rate Notes Due 2020 [Member]

1.85% Notes Due 2020 [Member]

2.35% Notes Due 2022 [Member]

2.75% Notes Due 2025 [Member]

3.70% Notes Due 2045 [Member]

Commercial paper [Member]

Short Term Foreign Borrowings [Member]

Notes Subject To Repayment At Option Of Holder [Member]

USD ($)

EUR (€)

USD ($)

EUR (€)

USD ($)

EUR (€)

USD ($)

Subsequent Event [Member]

USD ($)

EUR (€)

Debt Instrument [Line Items]

Long-term debt, current maturities

$1,000,000,000

$2,100,000,000

Loans payable and current portion of long-term debt

2,704,000,000

4,521,000,000

1,500,000,000

1,600,000,000

55,000,000

402,000,000

143,000,000

370,000,000

Weighted-average interest rate of commercial paper

0.15%

0.09%

Long-Term Debt

18,699,000,000

20,539,000,000

309,000,000

119,000,000

53,000,000

64,000,000

152,000,000

249,000,000

1,218,000,000

1,210,000,000

603,000,000

1,029,000,000

Average variable rate of other long term debt borrowings

0.00%

Maximum rate of foreign borrowings

6.25%

4.50%

Stated interest rate of senior unsecured notes

6.30%

1.13%

1.88%

2.50%

4.00%

6.00%

1.85%

2.35%

2.75%

3.70%

Debt Instrument, Face Amount

8,000,000,000

1,000,000,000

500,000,000

300,000,000

700,000,000

1,250,000,000

2,500,000,000

2,000,000,000

Proceeds from Issuance of Debt

3,100,000,000

Repayments of Debt

2,500,000,000

Extinguishment of Debt, Amount

1,800,000,000

Debt Instrument, Repurchased Face Amount

1,000,000,000

Loss on extinguishment of debt

628,000,000

Bridge Loan

8,000,000,000

Maximum total debt to capitalization ratio allowable by financial covenants under certain borrowings

60.00%

Long-term debt, maturities, repayments of principal in 2015

1,000,000,000

Long-term debt, maturities, repayments of principal in 2016

2,400,000,000

Long-term debt, maturities, repayments of principal in 2017

19,000,000

Long-term debt, maturities, repayments of principal in 2018

3,000,000,000

Long-term debt, maturities, repayments of principal in 2019

1,300,000,000

Available borrowing capacity under credit facility

6,000,000,000

Line of Credit Facility, Term

5 years

Rental expense under operating leases net of sublease income

350,000,000

367,000,000

396,000,000

Minimum aggregate rental commitments under noncancellable leases in 2015

232,000,000

Minimum aggregate rental commitments under noncancellable leases in 2016

122,000,000

Minimum aggregate rental commitments under noncancellable leases in 2017

92,000,000

Minimum aggregate rental commitments under noncancellable leases in 2018

55,000,000

Minimum aggregate rental commitments under noncancellable leases in 2019

46,000,000

Minimum aggregate rental commitments under noncancellable leases thereafter

$97,000,000

Contingencies_and_Environmenta1

Contingencies and Environmental Liabilities - Vioxx Litigation - Textual (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 28, 2015
	legalmatter	legalmatter
Vioxx MDL Litigation [Member] \| Vioxx [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	25
Cases alleging economic loss [Member] \| Vioxx [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	30
Litigation settlement agreement amount	$23,000,000
Vioxx Cases Brought by State Attorneys General [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	3
Vioxx Securities Lawsuits [Member]
Loss Contingencies [Line Items]
Upper limit of Directors and Officers insurance coverage	145,000,000
Vioxx Securities Lawsuits [Member] \| Subsequent Event [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number		6
Vioxx Canadian Litigation [Member] \| Minimum [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	21,000,000
Vioxx Canadian Litigation [Member] \| Maximum [Member]
Loss Contingencies [Line Items]
Loss Contingency, Estimate of Possible Loss	$36,000,000

Contingencies_and_Environmenta2

Contingencies and Environmental Liabilities - Fosamax Product Liability Litigation - Textual (Details) (Fosamax [Member], USD $)	12 Months Ended	0 Months Ended	1 Months Ended
	Dec. 31, 2014	Mar. 26, 2014	Dec. 31, 2013	Mar. 31, 2014	Nov. 30, 2013
	plaintiff	legalmatter		legalmatter	legalmatter
	legalmatter
Loss Contingencies [Line Items]
Loss contingency, pending claims number	5,575
Number of plaintiff groups	5,805
Femur Fracture Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	4,560
Femur Fracture Litigation [Member] \| Federal [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	1,035
Initial number of cases selected for review	33
Loss contingency, claims dismissed number		650
Number of Trials Scheduled	4
Femur Fracture Litigation [Member] \| New Jersey state court [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	3,005
Initial number of cases selected for review	30
Subsequent number of cases selected for review				50	50
Femur Fracture Litigation [Member] \| California State Court [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	515
Initial number of cases selected for review				10
Number of Trials Scheduled	2
Femur Fracture Litigation [Member] \| Other State Court [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	4
ONJ Litigation [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	1,015
Litigation settlement agreement amount			$27,700,000
Percentage of participation in litigation settlement condition			100.00%
Percentage of Participation in Litigation Settlement	95.00%
ONJ MDL [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	30

Contingencies_and_Environmenta3

Contingencies and Environmental Liabilities - Januvia/Janumet Litigation (Details) (Januvia [Member])	Dec. 31, 2014
	legalmatter
Loss Contingencies [Line Items]
Loss contingency, pending claims number	785
Cases Company Agreed ToToll Statute Of Limitations [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number	19

Contingencies_and_Environmenta4

Contingencies and Environmental Liabilities - NuvaRing Litigation - Textual (Details) (NuvaRing [Member], USD $)	0 Months Ended
	Jun. 04, 2014	Dec. 31, 2014
	legalmatter	legalmatter
NuvaRing [Member]
Loss Contingencies [Line Items]
Litigation settlement agreement amount	$100,000,000
Percentage of Participation in Litigation Settlement	95.00%
Loss Contingency, Claims Settled, Number	1,868
Loss contingency, pending claims number		80

Contingencies_and_Environmenta5

Contingencies and Environmental Liabilities - Propecia/Proscar Litigation - Textual (Details) (Propecia [Member])	12 Months Ended
	Dec. 31, 2014
	legalmatter
Loss Contingencies [Line Items]
Loss contingency, pending claims number	1,235
Number of plaintiff groups	1,500
Cases alleging cancer [Member]
Loss Contingencies [Line Items]
Number of plaintiff groups	50

Contingencies_and_Environmenta6

Contingencies and Environmental Liabilities Contingencies and Environmental Liabilities - Governmental Proceedings - Textual (Details) (Governmental Proceedings [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2014
	Dec. 31, 2011	legalmatter
Governmental Proceedings [Member]
Loss Contingencies [Line Items]
Loss contingency, pending claims number		2
Potentially improper payment	$300

Contingencies_and_Environmenta7

Contingencies and Environmental Liabilities - Legal Defense Reserves - Textual (Details) (Legal Defense Costs [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Legal Defense Costs [Member]
Loss Contingencies [Line Items]
Legal defense costs reserve	$215	$160

Contingencies_and_Environmenta8

Contingencies and Environmental Liabilities - Environmental Litigation and Matters - Textual (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Site Contingency [Line Items]
Accrued liabilities for environmental matters	$125,000,000	$213,000,000
Term for paying off environmental liabilities	15 years
Aggregate possible expenditure on environmental matters in excess of amounts accrued	66,000,000
Oss Netherlands [Member]
Site Contingency [Line Items]
Environmental remediation expense	$235,000

Equity_Shareholders_Equity_Det

Equity - Shareholders' Equity (Details)	12 Months Ended
Equity - Shareholders' Equity (Details)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Movement in Common Stock and Treasury Stock [Roll Forward]
Balance December 31	3,577,103,522		3,577,103,522
Accelerated share repurchase agreement (ASR) [Member]
Movement in Common Stock and Treasury Stock [Roll Forward]
Purchases of treasury stock			105,000,000
Common Stock [Member]
Movement in Common Stock and Treasury Stock [Roll Forward]
Balance January 1	3,577,000,000		3,577,000,000		3,577,000,000
Purchases of treasury stock	0	[1]	0	[1]	0	[1]
Issuances	0	[2]	0	[2]	0	[2]
Balance December 31	3,577,000,000		3,577,000,000		3,577,000,000
Treasury Stock [Member]
Movement in Common Stock and Treasury Stock [Roll Forward]
Balance January 1	650,000,000		550,000,000		536,000,000
Purchases of treasury stock	134,000,000	[1]	139,000,000	[1]	62,000,000	[1]
Issuances	-45,000,000	[2]	-39,000,000	[2]	-48,000,000	[2]
Balance December 31	739,000,000		650,000,000		550,000,000

[1]	Purchases of treasury stock in 2013 include 105 million shares purchased pursuant to an accelerated share repurchase agreement as discussed below.
[2]	Issuances primarily reflect activity under share-based compensation plans.

Equity_Textual_Details

Equity - Textual (Details) (USD $)	12 Months Ended
Equity - Textual (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 1998
Common stock, shares authorized	6,500,000,000	6,500,000,000
Preferred stock, shares authorized	20,000,000
Purchases of treasury stock	$7,703,000,000	$6,516,000,000	$2,591,000,000
Preferred stock dividend rate				5.00%
AstraZeneca LP [Member]
Par value preferred stock obligation assumed in connection with 1998 restructuring of AMI				2,400,000,000
Accelerated share repurchase agreement (ASR) [Member]
Purchases of treasury stock, shares		105,000,000
Purchases of treasury stock		$5,000,000,000

ShareBased_Compensation_Plans_1

Share-Based Compensation Plans - Assumptions Used to Determine Weighted-Average Fair Value of Options Granted (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected dividend yield	4.30%	4.20%	4.40%
Risk-free interest rate	2.00%	1.20%	1.30%
Expected volatility	22.00%	25.00%	25.20%
Expected life (years)	6 years 5 months	7 years	7 years

ShareBased_Compensation_Plans_2

Share-Based Compensation Plans - Textual (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares collectively authorized for future grants under share-based compensation plans	139
Quantity of stock options that vest per year	33.33%
Period for which awards under employee stock option are vested	3 years
Pretax share-based compensation cost	$278	$276	$335
Income tax benefits related to share-based compensation	86	84	105
Weighted average exercise price of options granted (in dollars per share)	$58.14	$45.01	$39.51
Weighted average fair value of options granted (in dollars per share)	$6.79	$6.21	$5.47
Total pre tax unrecognized compensation expense related to nonvested stock options, RSU and PSU awards	$401
Weighted average period in years of recognition for nonvested stock options, RSU and PSU awards	1 year 11 months
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term of options	7 years
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term of options	10 years

ShareBased_Compensation_Plans_3

Share-Based Compensation Plans - Summary of Information Relative to Stock Option Plan Activity (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of Options Outstanding, January 1 (in shares)	115,805
Number of Options, Granted (in shares)	4,872
Number of Options, Exercised (in shares)	-39,293
Number of Options, Forfeited (in shares)	-5,249
Number of Options Outstanding, December 31 (in shares)	76,135	115,805
Number of Options Exercisable (in shares)	65,324
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Options Outstanding, January 1 (in dollars per share)	$38.75
Weighted Average Exercise Price, Granted (in dollars per share)	$58.14	$45.01	$39.51
Weighted Average Exercise Price, Exercised (in dollars per share)	$39.71
Weighted Average Exercise Price, Forfeited (in dollars per share)	$45.28
Weighted Average Exercise Price, Options Outstanding, December 31 (in dollars per share)	$39.05	$38.75
Weighted Average Exercise Price Exercisable (in dollars per share)	$37.56
Weighted Average Remaining Contractual Term, Outstanding	3 years 10 months 5 days
Weighted Average Remaining Contractual Term, Exercisable	3 years 2 months 15 days
Aggregate Intrinsic Value, Outstanding	$1,358
Aggregate Intrinsic Value, Exercisable	$1,257

ShareBased_Compensation_Plans_4

Share-Based Compensation Plans - Additional Information Pertaining to Stock Option Plans (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Total intrinsic value of stock options exercised	$626	$374	$528
Fair value of stock options vested	35	42	80
Cash received from the exercise of stock options	$1,560	$1,210	$1,310

ShareBased_Compensation_Plans_5

Share-Based Compensation Plans - Summary of Nonvested RSU and PSU Activity (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Shares, Nonvested January 1	19,134
Number of Shares, Granted	4,776
Number of Shares, Vested	-6,866
Number of Shares, Forfeited	-1,410
Number of Shares, Nonvested December 31	15,634
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Nonvested January 1 (in dollars per share)	$40.07
Weighted Average Grant Date Fair Value, Granted (in dollars per share)	$58.13
Weighted Average Grant Date Fair Value, Vested (in dollars per share)	$36.36
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share)	$46.22
Weighted Average Grant Date Fair Value, Nonvested December 31 (in dollars per share)	$46.66
PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of Shares, Nonvested January 1	1,673
Number of Shares, Granted	1,224
Number of Shares, Vested	-723
Number of Shares, Forfeited	-292
Number of Shares, Nonvested December 31	1,882
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Nonvested January 1 (in dollars per share)	$35.98
Weighted Average Grant Date Fair Value, Granted (in dollars per share)	$62.94
Weighted Average Grant Date Fair Value, Vested (in dollars per share)	$33.97
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share)	$45.49
Weighted Average Grant Date Fair Value, Nonvested December 31 (in dollars per share)	$52.81

Pension_and_Other_Postretireme2

Pension and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Cost (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$300	$386	$324
Interest cost	425	402	401
Expected return on plan assets	-782	-721	-617
Net amortization	74	251	149
Termination benefits	53	51	17
Curtailments	-69	-22	-11
Settlements	11	1	5
Net periodic benefit cost	12	348	268
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	266	296	231
Interest cost	269	263	260
Expected return on plan assets	-416	-376	-354
Net amortization	59	85	36
Termination benefits	11	7	10
Curtailments	-4	-1	2
Settlements	6	22	13
Net periodic benefit cost	191	296	198
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	78	102	82
Interest cost	115	107	121
Expected return on plan assets	-139	-126	-136
Net amortization	-71	-50	-35
Termination benefits	22	50	18
Curtailments	-39	-11	-7
Settlements	0	0	0
Net periodic benefit cost	($34)	$72	$43

Pension_and_Other_Postretireme3

Pension and Other Postretirement Benefit Plans - Obligation and Funded Status (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
U.S. [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	$10,007	$8,683
Actual return on plan assets	484	1,821
Company contributions	92	54
Effects of exchange rate changes	0	0
Benefits paid	-535	-542
Settlements	-64	-9
Other	0	0
Fair value of plan assets December 31	9,984	10,007	8,683
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation January 1	8,666	9,961
Service cost	300	386	324
Interest cost	425	402	401
Actuarial losses (gains)	1,857	-1,565
Benefits paid	-535	-542
Effects of exchange rate changes	0	0
Plan amendments	0	1
Curtailments	-70	-19
Termination benefits	53	51	17
Settlements	-64	-9
Other	0	0
Benefit obligation December 31	10,632	8,666	9,961
Funded status December 31	-648	1,341
Recognized as:
Other assets	68	2,106
Accrued and other current liabilities	-41	-44
Other noncurrent liabilities	-675	-721
International [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	7,428	6,666
Actual return on plan assets	1,099	703
Company contributions	276	591
Effects of exchange rate changes	-816	-84
Benefits paid	-245	-238
Settlements	-31	-227
Other	13	17
Fair value of plan assets December 31	7,724	7,428	6,666
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation January 1	7,389	7,685
Service cost	266	296	231
Interest cost	269	263	260
Actuarial losses (gains)	1,605	-124
Benefits paid	-245	-238
Effects of exchange rate changes	-864	-21
Plan amendments	-4	-226
Curtailments	-76	-42
Termination benefits	11	7	10
Settlements	-31	-227
Other	11	16
Benefit obligation December 31	8,331	7,389	7,685
Funded status December 31	-607	39
Recognized as:
Other assets	565	705
Accrued and other current liabilities	-11	-9
Other noncurrent liabilities	-1,161	-657
Other Postretirement Benefits [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	1,913	1,760
Actual return on plan assets	114	199
Company contributions	67	73
Effects of exchange rate changes	0	0
Benefits paid	-110	-119
Settlements	0	0
Other	0	0
Fair value of plan assets December 31	1,984	1,913	1,760
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit obligation January 1	2,329	2,650
Service cost	78	102	82
Interest cost	115	107	121
Actuarial losses (gains)	212	-428
Benefits paid	-110	-119
Effects of exchange rate changes	-6	-5
Plan amendments	0	-38
Curtailments	3	0
Termination benefits	22	50	18
Settlements	0	0
Other	-5	10
Benefit obligation December 31	2,638	2,329	2,650
Funded status December 31	-654	-416
Recognized as:
Other assets	1	0
Accrued and other current liabilities	-11	-8
Other noncurrent liabilities	($644)	($408)

Pension_and_Other_Postretireme4

Pension and Other Postretirement Benefit Plans - Textual (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$17,900,000,000	$14,800,000,000
Percentage of Company's pension investments categorized as Level 3 assets	3.00%	4.00%
Employer contributions to defined contribution savings plans	124,000,000	138,000,000	146,000,000
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected annual standard deviation in returns of the target portfolio which reflects both the equity allocation and the diversification benefits among the asset classes in which the portfolio invests	13.00%
Expected rate of return on plan assets	8.50%	8.50%	8.70%
United States [Member] \| Minimum [Member] \| Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected rate of return on plan assets				7.30%
United States [Member] \| Maximum [Member] \| Scenario, Forecast [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected rate of return on plan assets				8.75%
United States [Member] \| U.S. Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum percentage allocation of target investment portfolio of the Company's U.S. pension and other postretirement benefit plans	40.00%
Maximum percentage allocation of target investment portfolio of the Company's U.S. pension and other postretirement benefit plans	60.00%
United States [Member] \| International Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum percentage allocation of target investment portfolio of the Company's U.S. pension and other postretirement benefit plans	20.00%
Maximum percentage allocation of target investment portfolio of the Company's U.S. pension and other postretirement benefit plans	40.00%
United States [Member] \| Fixed Income Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Minimum percentage allocation of target investment portfolio of the Company's U.S. pension and other postretirement benefit plans	15.00%
Maximum percentage allocation of target investment portfolio of the Company's U.S. pension and other postretirement benefit plans	25.00%
United States [Member] \| Cash And Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum percentage allocation of target investment portfolio of the Company's U.S. pension and other postretirement benefit plans	5.00%
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	10,100,000,000	8,000,000,000
Fair Value of Plan Assets	9,984,000,000	10,007,000,000	8,683,000,000
Expected contributions to the pension plans and other postretirement benefit plans during next fiscal year	40,000,000
Estimated net loss (gain) amounts that will be amortized from AOCI into net pension and postretirement benefit cost during next fiscal year	227,000,000
Estimated prior service cost (credit) amounts that will be amortized from AOCI into net pension and postretirement benefit cost during next fiscal year	-57,000,000
U.S. [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	28,000,000	31,000,000	32,000,000
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	7,724,000,000	7,428,000,000	6,666,000,000
Expected contributions to the pension plans and other postretirement benefit plans during next fiscal year	150,000,000
Expected rate of return on plan assets	6.00%	5.80%	5.90%
International [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	552,000,000	591,000,000	660,000,000
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated net loss (gain) amounts that will be amortized from AOCI into net pension and postretirement benefit cost during next fiscal year	353,000,000
Estimated prior service cost (credit) amounts that will be amortized from AOCI into net pension and postretirement benefit cost during next fiscal year	-72,000,000
Pension Plan [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	580,000,000	622,000,000
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,984,000,000	1,913,000,000	1,760,000,000
Expected contributions to the pension plans and other postretirement benefit plans during next fiscal year	65,000,000
Estimated net loss (gain) amounts that will be amortized from AOCI into net pension and postretirement benefit cost during next fiscal year	4,000,000
Estimated prior service cost (credit) amounts that will be amortized from AOCI into net pension and postretirement benefit cost during next fiscal year	-65,000,000
Other Postretirement Benefits [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$0	$0

Pension_and_Other_Postretireme5

Pension and Other Postretirement Benefit Plans - Accumulated and Projected Benefit Obligation in Excess of Plan Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
U.S. [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected benefit obligation	$3,963	$764
Fair value of plan assets	3,247	0
Accumulated benefit obligation	810	619
Fair value of plan assets	138	0
International [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected benefit obligation	5,513	2,196
Fair value of plan assets	4,341	1,529
Accumulated benefit obligation	2,749	1,871
Fair value of plan assets	$1,870	$1,424

Pension_and_Other_Postretireme6

Pension and Other Postretirement Benefit Plans - Fair Values of Pension Plan Assets (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$9,984		$10,007		$8,683
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	7,724		7,428		6,666
Cash and cash equivalents [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	236		169
Cash and cash equivalents [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	221		166
Developed markets equities, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,058		5,353
Developed markets equities, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,208		3,099
Emerging markets equities, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	825		834
Emerging markets equities, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	287		365
Government and agency obligations, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	31		29
Government and agency obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,727		1,444
Corporate obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	353		265
Fixed income obligations, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	132		125
Fixed income obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	25		37
Real estate, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	37	[1]	110	[1]
Developed markets, Equity securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,169		2,138
Developed markets, Equity securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	509		407
Government and agency obligations, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	516		444
Government and agency obligations, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	476		654
Corporate obligations, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	722		590
Corporate obligations, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	193		151
Mortgage and asset backed-securities, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	245		245
Mortgage and asset backed-securities, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	90		54
Derivatives, Other investments [Member] \| U.S. [Member] \| Liability [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	10		0
Derivatives, Other investments [Member] \| U.S. [Member] \| Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	32		1
Insurance contracts, Other investments [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	590	[2]	668	[2]
Other, Other investments [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	28		79
Other, Other investments [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8		8
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,819		2,766
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,507		1,343
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Cash and cash equivalents [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2		-54
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Cash and cash equivalents [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	208		142
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Developed markets equities, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	540		581
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Developed markets equities, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	217		227
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Emerging markets equities, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	107		100
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Emerging markets equities, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	31		63
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Government and agency obligations, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Government and agency obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	317		293
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Corporate obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	183		188
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Fixed income obligations, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Fixed income obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	9		17
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Real estate, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	[1]	4	[1]
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Developed markets, Equity securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,169		2,138
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Developed markets, Equity securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	509		407
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Government and agency obligations, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Government and agency obligations, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	28		2
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Corporate obligations, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Corporate obligations, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2		0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Mortgage and asset backed-securities, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Mortgage and asset backed-securities, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Derivatives, Other investments [Member] \| U.S. [Member] \| Liability [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Derivatives, Other investments [Member] \| U.S. [Member] \| Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1		1
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Insurance contracts, Other investments [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	[2]	0	[2]
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Other, Other investments [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Other, Other investments [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3		0
Significant Other Observable Inputs (Level 2) [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	7,137		7,210
Significant Other Observable Inputs (Level 2) [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,665		5,494
Significant Other Observable Inputs (Level 2) [Member] \| Cash and cash equivalents [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	234		223
Significant Other Observable Inputs (Level 2) [Member] \| Cash and cash equivalents [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	13		24
Significant Other Observable Inputs (Level 2) [Member] \| Developed markets equities, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,518		4,772
Significant Other Observable Inputs (Level 2) [Member] \| Developed markets equities, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,991		2,872
Significant Other Observable Inputs (Level 2) [Member] \| Emerging markets equities, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	718		734
Significant Other Observable Inputs (Level 2) [Member] \| Emerging markets equities, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	256		302
Significant Other Observable Inputs (Level 2) [Member] \| Government and agency obligations, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	31		29
Significant Other Observable Inputs (Level 2) [Member] \| Government and agency obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,410		1,151
Significant Other Observable Inputs (Level 2) [Member] \| Corporate obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	170		77
Significant Other Observable Inputs (Level 2) [Member] \| Fixed income obligations, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	132		125
Significant Other Observable Inputs (Level 2) [Member] \| Fixed income obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16		20
Significant Other Observable Inputs (Level 2) [Member] \| Real estate, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8	[1]	57	[1]
Significant Other Observable Inputs (Level 2) [Member] \| Developed markets, Equity securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Other Observable Inputs (Level 2) [Member] \| Developed markets, Equity securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Other Observable Inputs (Level 2) [Member] \| Government and agency obligations, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	516		444
Significant Other Observable Inputs (Level 2) [Member] \| Government and agency obligations, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	448		652
Significant Other Observable Inputs (Level 2) [Member] \| Corporate obligations, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	722		590
Significant Other Observable Inputs (Level 2) [Member] \| Corporate obligations, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	190		151
Significant Other Observable Inputs (Level 2) [Member] \| Mortgage and asset backed-securities, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	245		245
Significant Other Observable Inputs (Level 2) [Member] \| Mortgage and asset backed-securities, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	90		54
Significant Other Observable Inputs (Level 2) [Member] \| Derivatives, Other investments [Member] \| U.S. [Member] \| Liability [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	10		0
Significant Other Observable Inputs (Level 2) [Member] \| Derivatives, Other investments [Member] \| U.S. [Member] \| Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	31		0
Significant Other Observable Inputs (Level 2) [Member] \| Insurance contracts, Other investments [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	69	[2]	128	[2]
Significant Other Observable Inputs (Level 2) [Member] \| Other, Other investments [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		48
Significant Other Observable Inputs (Level 2) [Member] \| Other, Other investments [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4		6
Significant Unobservable Inputs (Level 3) [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	28		31		32
Significant Unobservable Inputs (Level 3) [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	552		591		660
Significant Unobservable Inputs (Level 3) [Member] \| Cash and cash equivalents [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Cash and cash equivalents [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Developed markets equities, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Developed markets equities, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Emerging markets equities, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Emerging markets equities, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Government and agency obligations, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Government and agency obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Corporate obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Fixed income obligations, Investment funds [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Fixed income obligations, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Real estate, Investment funds [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	29	[1]	49	[1]
Significant Unobservable Inputs (Level 3) [Member] \| Developed markets, Equity securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Developed markets, Equity securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Government and agency obligations, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Government and agency obligations, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Corporate obligations, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Corporate obligations, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1		0
Significant Unobservable Inputs (Level 3) [Member] \| Mortgage and asset backed-securities, Fixed income securities [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Mortgage and asset backed-securities, Fixed income securities [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Derivatives, Other investments [Member] \| U.S. [Member] \| Liability [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Derivatives, Other investments [Member] \| U.S. [Member] \| Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Significant Unobservable Inputs (Level 3) [Member] \| Insurance contracts, Other investments [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0		0
Significant Unobservable Inputs (Level 3) [Member] \| Insurance contracts, Other investments [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	521	[2]	540	[2]	496
Significant Unobservable Inputs (Level 3) [Member] \| Other, Other investments [Member] \| U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	28		31
Significant Unobservable Inputs (Level 3) [Member] \| Other, Other investments [Member] \| International [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$1		$2

[1]	The plansâ€™ LevelÂ 3 investments in real estate funds are generally valued by market appraisals of the underlying investments in the funds.
[2]	The plansâ€™ LevelÂ 3 investments in insurance contracts are generally valued using a crediting rate that approximates market returns and invest in underlying securities whose market values are unobservable and determined using pricing models, discounted cash flow methodologies, or similar techniques.

Pension_and_Other_Postretireme7

Pension and Other Postretirement Benefit Plans - Summary of Changes in Fair Value of Company's Level 3 Pension Plan Assets (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
U.S. [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1					$8,683
Fair value of plan assets December 31	9,984		10,007		8,683
U.S. [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	31		32
Relating to assets still held at December 31	1		1
Relating to assets sold during the year	4		3
Purchases	1		2
Sales	-9		-7
Fair value of plan assets December 31	28		31
U.S. [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Insurance Contracts [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	0		0
Relating to assets still held at December 31	0		0
Relating to assets sold during the year	0		0
Purchases	0		0
Sales	0		0
Fair value of plan assets December 31	0		0
U.S. [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Real Estate [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	0		0
Relating to assets still held at December 31	0		0
Relating to assets sold during the year	0		0
Purchases	0		0
Sales	0		0
Fair value of plan assets December 31	0		0
U.S. [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Other Investment [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	31		32
Relating to assets still held at December 31	1		1
Relating to assets sold during the year	4		3
Purchases	1		2
Sales	-9		-7
Fair value of plan assets December 31	28		31
International [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1					6,666
Fair value of plan assets December 31	7,724		7,428		6,666
International [Member] \| Insurance Contracts [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets December 31	590	[1]	668	[1]
International [Member] \| Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	591		660
Relating to assets still held at December 31	-39		30
Relating to assets sold during the year	0		0
Purchases	22		18
Sales	-13		-23
Transfers out of Level 3	-9		-94
Fair value of plan assets December 31	552		591
International [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Insurance Contracts [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	540	[1]	496
Relating to assets still held at December 31	-35		30
Relating to assets sold during the year	0		1
Purchases	22		18
Sales	-3		-2
Transfers out of Level 3	-3		-3
Fair value of plan assets December 31	521	[1]	540	[1]
International [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Real Estate [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	49		141
Relating to assets still held at December 31	-4		0
Relating to assets sold during the year	0		-1
Purchases	0		0
Sales	-10		0
Transfers out of Level 3	-6		-91
Fair value of plan assets December 31	29		49
International [Member] \| Significant Unobservable Inputs (Level 3) [Member] \| Other Investment [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets January 1	2		23
Relating to assets still held at December 31	0		0
Relating to assets sold during the year	0		0
Purchases	0		0
Sales	0		-21
Transfers out of Level 3	0		0
Fair value of plan assets December 31	$2		$2

[1]	The plansâ€™ LevelÂ 3 investments in insurance contracts are generally valued using a crediting rate that approximates market returns and invest in underlying securities whose market values are unobservable and determined using pricing models, discounted cash flow methodologies, or similar techniques.

Pension_and_Other_Postretireme8

Pension and Other Postretirement Benefit Plans - Fair Values of Other Postretirement Benefit Plan Assets (Details) (Other Postretirement Benefits [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$1,984	$1,913	$1,760
Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	80	67
Developed markets equities, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	664	721
Emerging markets equities, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	129	131
Government and agency obligations, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5	0
Fixed income obligations, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	12	17
Developed markets, Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	204	199
Government and agency obligations, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	333	257
Corporate obligations, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	336	281
Mortgage and asset-backed securities, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	219	219
Other fixed income obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	21
Derivatives, Other investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2	0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	354	339
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	60	47
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Developed markets equities, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	51	54
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Emerging markets equities, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	36	36
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Government and agency obligations, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3	0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Fixed income obligations, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	3
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Developed markets, Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	204	199
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Government and agency obligations, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Corporate obligations, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Mortgage and asset-backed securities, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Other fixed income obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member] \| Derivatives, Other investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,630	1,574
Significant Other Observable Inputs (Level 2) [Member] \| Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	20	20
Significant Other Observable Inputs (Level 2) [Member] \| Developed markets equities, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	613	667
Significant Other Observable Inputs (Level 2) [Member] \| Emerging markets equities, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	93	95
Significant Other Observable Inputs (Level 2) [Member] \| Government and agency obligations, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2	0
Significant Other Observable Inputs (Level 2) [Member] \| Fixed income obligations, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	12	14
Significant Other Observable Inputs (Level 2) [Member] \| Developed markets, Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Other Observable Inputs (Level 2) [Member] \| Government and agency obligations, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	333	257
Significant Other Observable Inputs (Level 2) [Member] \| Corporate obligations, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	336	281
Significant Other Observable Inputs (Level 2) [Member] \| Mortgage and asset-backed securities, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	219	219
Significant Other Observable Inputs (Level 2) [Member] \| Other fixed income obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	21
Significant Other Observable Inputs (Level 2) [Member] \| Derivatives, Other investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2	0
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Developed markets equities, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Emerging markets equities, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Government and agency obligations, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Fixed income obligations, Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Developed markets, Equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Government and agency obligations, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Corporate obligations, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Mortgage and asset-backed securities, Fixed income securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Other fixed income obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Significant Unobservable Inputs (Level 3) [Member] \| Derivatives, Other investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$0	$0

Pension_and_Other_Postretireme9

Pension and Other Postretirement Benefit Plans - Summary of Expected Benefit Payments (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified	Dec. 31, 2014
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
2015	$469
2016	495
2017	491
2018	525
2019	549
2020 â€” 2024	3,238
International [Member]
Defined Benefit Plan Disclosure [Line Items]
2015	213
2016	185
2017	192
2018	206
2019	215
2020 â€” 2024	1,323
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2015	109
2016	117
2017	124
2018	131
2019	138
2020 â€” 2024	$792

Recovered_Sheet1

Pension and Other Postretirement Benefit Plans - Components of Other Comprehensive Income (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Net (loss) gain arising during the period	($2,085)	$2,676	($688)
Prior service (cost) credit arising during the period	-59	-23	-16
Total	-2,144	2,653	-704
Net loss amortization included in benefit cost	135	318	217
Prior service (credit) cost amortization included in benefit cost	-61	-67	-68
Total	74	251	149
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Net (loss) gain arising during the period	-779	513	-1,219
Prior service (cost) credit arising during the period	-8	226	3
Total	-787	739	-1,216
Net loss amortization included in benefit cost	74	89	39
Prior service (credit) cost amortization included in benefit cost	-15	-4	-3
Total	59	85	36
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net (loss) gain arising during the period	-223	499	-24
Prior service (cost) credit arising during the period	-42	26	78
Total	-265	525	54
Net loss amortization included in benefit cost	1	23	31
Prior service (credit) cost amortization included in benefit cost	-72	-73	-66
Total	($71)	($50)	($35)

Recovered_Sheet2

Pension and Other Postretirement Benefit Plans - Summary of Weighted Average Assumptions Used in Determining Pension Plan and U.S. Pension and Other Postretirement Benefit Plan Information (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
United States [Member]
Net periodic benefit cost
Discount rate	4.90%	4.10%	4.80%
Expected rate of return on plan assets	8.50%	8.50%	8.70%
Salary growth rate	4.50%	4.50%	4.50%
Benefit obligation
Discount rate	4.20%	5.10%	4.10%
Salary growth rate	4.40%	4.50%	4.50%
International [Member]
Net periodic benefit cost
Discount rate	3.80%	3.60%	4.60%
Expected rate of return on plan assets	6.00%	5.80%	5.90%
Salary growth rate	3.10%	3.30%	3.40%
Benefit obligation
Discount rate	2.70%	3.80%	3.60%
Salary growth rate	2.90%	3.10%	3.30%

Recovered_Sheet3

Pension and Other Postretirement Benefit Plans - Summary of Health Care Cost Trend Rate Assumptions for Other Postretirement Benefit Plans (Details) (Other Postretirement Benefits [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate assumed for next year	6.90%	7.10%
Rate to which the cost trend rate is assumed to decline	4.60%	4.60%
Year that the trend rate reaches the ultimate trend rate	2027	2027

Recovered_Sheet4

Pension and Other Postretirement Benefit Plans - One Percentage Point Change in Health Care Cost Trend Rate (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Effect on total service and interest cost components, Increase	$32
Effect on benefit obligation, Increase	421
Effect on total service and interest cost components, Decrease	-27
Effect on benefit obligation, Decrease	($339)

Other_Income_Expense_Net_Detai

Other (Income) Expense, Net (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Income and Expenses [Abstract]
Interest income	($266)	($264)	($232)
Interest expense	732	801	714
Exchange losses	180	290	185
Other, net	-12,002	-12	449
Other (income) expense, net	($11,356)	$815	$1,116

Other_Income_Expense_Net_Textu

Other (Income) Expense, Net - Textual (Details)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Feb. 28, 2013	Jan. 31, 2013
	USD ($)	USD ($)	USD ($)	Santen Pharmaceutical Co. Ltd. [Member]	Sirna Therapeutics Inc. [Member]	Supera [Member]	Consumer Care [Member]	Venezuela [Member]	Venezuela [Member]	Venezuela [Member]
				USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	VEF	VEF
Component of Other Income / Expense of Nonoperating [Line Items]
Foreign currency exchange losses	$180	$290	$185					$140
Foreign Currency Exchange Rate, Translation									6.3	4.3
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	11,209	0	0				11,200
Gain on disposition of interest in equity method investment	741	0	0
Gain (Loss) on Disposition of Business				480
Gain (Loss) on Disposition of Other Assets					204
Loss on extinguishment of debt	628	0	0
Goodwill, Impairment Loss	93					93
Litigation charges			493
Interest paid	$852	$922	$808

Taxes_on_Income_Reconciliation

Taxes on Income - Reconciliation Between Effective Tax Rate and US Statutory Rate (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Amount
U.S. statutory rate applied to income before taxes	$6,049		$1,941		$3,059
Differential arising from:
Foreign earnings	-1,486		-1,316		-1,955
AstraZeneca option exercise	-774		0		0
Sale of Sirna Therapeutics, Inc.	-357		0		0
Tax settlements	-89		-497		-113
The American Taxpayer Relief Act of 2012	0		-269		0
Unremitted foreign earnings	-209		-81		-11
Amortization of purchase accounting adjustments	865		934		905
Divestiture of Merck Consumer Care	440		0
Restructuring	289		224		62
U.S. health care reform legislation	134		65		60
Intangible asset impairment charges	148		56		40
Vioxx and ENHANCE litigation settlements	0		0		98
State taxes	7		44		31
Other	332	[1]	-73	[1]	264	[1]
Taxes on income	$5,349		$1,028		$2,440
Tax Rate
U.S. statutory rate applied to income before taxes	35.00%		35.00%		35.00%
Differential arising from:
Foreign earnings	-8.60%		-23.70%		-22.40%
AstraZeneca option exercise	-4.50%		0.00%		0.00%
Sale of Sirna Therapeutics, Inc.	-2.10%		0.00%		0.00%
Tax settlements	-0.50%		-9.00%		-1.30%
The American Taxpayer Relief Act of 2012			-4.80%
Unremitted foreign earnings	-1.20%		-1.50%		-0.10%
Amortization of purchase accounting adjustments	5.00%		16.80%		10.30%
Divestiture of Merck Consumer Care	2.50%		0.00%		0.00%
Restructuring	1.70%		4.00%		0.70%
U.S. health care reform legislation	0.80%		1.20%		0.70%
Intangible asset impairment charges	0.90%		1.00%		0.50%
Vioxx and ENHANCE litigation settlements	0.00%		0.00%		1.20%
State taxes	0.00%		0.80%		0.30%
Other	1.90%	[1]	-1.30%	[1]	3.00%	[1]
Total, Tax Rate	30.90%		18.50%		27.90%

[1]	Other includes the tax effect of contingency reserves, research credits, tax rate changes and miscellaneous items.

Taxes_on_Income_Income_Before_

Taxes on Income - Income Before Taxes (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Domestic	$15,730	$3,513	$4,500
Foreign	1,553	2,032	4,239
Income Before Taxes	$17,283	$5,545	$8,739

Taxes_on_Income_Taxes_on_Incom

Taxes on Income - Taxes on Income (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current provision
Federal	$7,136	$568	$1,346
Foreign	438	923	651
State	375	-133	-226
Total current provision	7,949	1,358	1,771
Deferred provision
Federal	-2,162	30	749
Foreign	-201	-398	-323
State	-237	38	243
Total deferred provision	-2,600	-330	669
Taxes on income	$5,349	$1,028	$2,440

Taxes_on_Income_Deferred_Incom

Taxes on Income - Deferred Income Taxes (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax [Line Items]
Inventory related, Assets	$56	$49
Accelerated depreciation, Assets	58	125
Equity investments, Assets	5	0
Pensions and other postretirement benefits, Assets	778	162
Compensation related, Assets	578	600
Unrecognized tax benefits, Assets	401	497
Net operating losses and other tax credit carryforwards, Assets	379	225
Other, Assets	1,530	1,605
Subtotal, Assets	3,785	3,263
Valuation allowance, Assets	-265	-205
Deferred Tax Assets	3,520	3,058
Intangibles, Liabilities	3,358	3,772
Inventory related, Liabilities	699	604
Accelerated depreciation, Liabilities	892	1,215
Unremitted foreign earnings, Liabilities	2,016	2,361
Equity investments, Liabilities	0	539
Pensions and other postretirement benefits, Liabilities	156	543
Other, Liabilities	65	71
Subtotal, Liabilities	7,186	9,105
Deferred Tax Liabilities	3,666	6,047
Deferred Income Taxes	4,266	6,776
Deferred income taxes and other current assets [Member]
Income Tax [Line Items]
Deferred Tax Assets	568	572
Other assets [Member]
Income Tax [Line Items]
Deferred Tax Assets	401	381
Income Taxes Payable [Member]
Income Tax [Line Items]
Deferred Tax Liabilities	$369	$224

Taxes_on_Income_Unrecognized_T

Taxes on Income - Unrecognized Tax Benefits (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance January 1	$3,503		$4,425		$4,277
Additions related to current year positions	389		320		496
Additions related to prior year positions	23		177		58
Reductions for tax positions of prior years	-156	[1]	-747	[1]	-320	[1]
Settlements	-161		-603		-67
Lapse of statute of limitations	-64		-69		-19
Balance December 31	$3,534		$3,503		$4,425

[1]	Amounts reflect the settlements with the IRS and CRA as discussed below.

Taxes_on_Income_Textual_Detail

Taxes on Income - Textual (Details) (USD $)	12 Months Ended
Taxes on Income - Textual (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Income Tax [Line Items]
U.S. statutory rate applied to income before taxes	35.00%		35.00%		35.00%
Deferred tax assets on NOL carryforwards relating to foreign jurisdictions	$203,000,000
Deferred tax assets relating to various U.S. tax credit carryforwards and NOL carryforwards	175,000,000
Income taxes paid	7,900,000,000		2,300,000,000		2,500,000,000
Tax Benefit Realized from Exercise of Stock Options	202,000,000		70,000,000		81,000,000
Unrecognized tax benefits	3,534,000,000		3,503,000,000		4,425,000,000		4,277,000,000
Favorable net impact to income tax provision if unrecognized tax benefits were recognized	3,300,000,000
Reasonably possible amount that liability for unrecognized tax benefits could decline up to in next 12 months	1,300,000,000
Interest and penalties associated with uncertain tax positions, expense (benefit)	9,000,000		-319,000,000		-88,000,000
Liabilities for accrued interest and penalties	659,000,000		665,000,000
Decrease in unrecognized tax benefits resulting from prior period tax positions	156,000,000	[1]	747,000,000	[1]	320,000,000	[1]
Foreign earnings retained indefinitely by subsidiary companies for reinvestments	60,000,000,000
The American Taxpayer Relief Act of 2012	0		269,000,000		0
Consumer Care [Member]
Income Tax [Line Items]
Income taxes paid	5,000,000,000
Foreign Jurisdiction [Member]
Income Tax [Line Items]
Valuation allowance on foreign NOL carryforwards	265,000,000
IRS [Member]
Income Tax [Line Items]
Decrease in unrecognized tax benefits resulting from prior period tax positions			165,000,000
IRS [Member] \| Intercompany pricing matters [Member]
Income Tax [Line Items]
Decrease in unrecognized tax benefits resulting from prior period tax positions			160,000,000
Canada Revenue Agency (CRA) [Member]
Income Tax [Line Items]
Decrease in unrecognized tax benefits resulting from prior period tax positions					112,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority					$65,000,000

[1]	Amounts reflect the settlements with the IRS and CRA as discussed below.

Earnings_Per_Share_Calculation

Earnings Per Share - Calculations of Earnings Per Share (Details) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Basic Earnings per Common Share
Net Income Attributable to Merck & Co., Inc.	$11,920		$4,404		$6,168
Less: Income allocated to participating securities	0		0		3
Net income allocated to common shareholders	11,920		4,404		6,165
Average common shares outstanding	2,894		2,963		3,041
Basic Earnings per Common Share (in dollars per share)	$4.12		$1.49		$2.03
Earnings per Common Share Assuming Dilution
Net Income Attributable to Merck & Co., Inc.	11,920		4,404		6,168
Less: Income allocated to participating securities	0		0		3
Net income allocated to common shareholders	$11,920		$4,404		$6,165
Average common shares outstanding	2,894		2,963		3,041
Common shares issuable	34	[1]	33	[1]	35	[1]
Average common shares outstanding assuming dilution	2,928		2,996		3,076
Diluted Earnings per Common Share (in dollars per share)	$4.07		$1.47		$2

[1]	Issuable primarily under share-based compensation plans.

Earnings_Per_Share_Textual_Det

Earnings Per Share - Textual (Details)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Period for which awards under employee stock option are vested	3 years
Common shares issuable under share-based compensation plans excluded from diluted earnings per common share because the effect would have been antidilutive	4	25	104

Other_Comprehensive_Income_Los2

Other Comprehensive Income (Loss) - Changes in AOCI by Component (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	($2,197)		($4,682)		($3,132)
Other comprehensive income (loss) before reclassification adjustments, pretax	-2,782		3,902		-2,075
Tax	673		-1,620		436
Other comprehensive income (loss) before reclassification adjustments, net of taxes	-2,109		2,282		-1,639
Reclassification adjustments, pretax	-41		289		156
Tax	24		-86		-67
Reclassification adjustments, net of taxes	-17		203		89
Other comprehensive income (loss), net of taxes	-2,126		2,485		-1,550
Accumulated Other Comprehensive Income (Loss), ending balance	-4,323		-2,197		-4,682
Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	132		-97		4
Other comprehensive income (loss) before reclassification adjustments, pretax	778		335		-198
Tax	-285		-132		77
Other comprehensive income (loss) before reclassification adjustments, net of taxes	493		203		-121
Reclassification adjustments, pretax	-146		42		33
Tax	51		-16		-13
Reclassification adjustments, net of taxes	-95	[1]	26	[1]	20	[1]
Other comprehensive income (loss), net of taxes	398		229		-101
Accumulated Other Comprehensive Income (Loss), ending balance	530		132		-97
Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	54		73		21
Other comprehensive income (loss) before reclassification adjustments, pretax	48		33		74
Tax	-17		-23		-10
Other comprehensive income (loss) before reclassification adjustments, net of taxes	31		10		64
Reclassification adjustments, pretax	43		-39		-13
Tax	-17		10		1
Reclassification adjustments, net of taxes	26	[2]	-29	[2]	-12	[2]
Other comprehensive income (loss), net of taxes	57		-19		52
Accumulated Other Comprehensive Income (Loss), ending balance	111		54		73
Employee Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	-909	[3]	-3,667		-2,346
Other comprehensive income (loss) before reclassification adjustments, pretax	-3,196		3,917		-1,852
Tax	1,067		-1,365		450
Other comprehensive income (loss) before reclassification adjustments, net of taxes	-2,129		2,552		-1,402
Reclassification adjustments, pretax	62		286		136
Tax	-10		-80		-55
Reclassification adjustments, net of taxes	52	[4]	206	[4]	81	[4]
Other comprehensive income (loss), net of taxes	-2,077		2,758		-1,321
Accumulated Other Comprehensive Income (Loss), ending balance	-2,986	[3]	-909	[3]	-3,667
Cumulative Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	-1,474		-991		-811
Other comprehensive income (loss) before reclassification adjustments, pretax	-412		-383		-99
Tax	-92		-100		-81
Other comprehensive income (loss) before reclassification adjustments, net of taxes	-504		-483		-180
Reclassification adjustments, pretax	0		0		0
Tax	0		0		0
Reclassification adjustments, net of taxes	0		0		0
Other comprehensive income (loss), net of taxes	-504		-483		-180
Accumulated Other Comprehensive Income (Loss), ending balance	($1,978)		($1,474)		($991)

[1]	Relates to foreign currency cash flow hedges that were reclassified from AOCI to Sales.
[2]	Represents net realized (gains) losses on the sales of available-for-sale investments that were reclassified from AOCI to Other (income) expense, net.
[3]	Includes pension plan net loss of $(3.5) billion and $(1.7) billion at December 31, 2014 and 2013, respectively, and other postretirement benefit plan net loss of $(228) million and $(80) million at December 31, 2014 and in 2013, respectively, as well as pension plan prior service credit of $473 million and $559 million at December 31, 2014 and 2013, respectively, and other postretirement benefit plan prior service credit of $257 million and $331 million at December 31, 2014 and 2013.
[4]	Includes net amortization of prior service cost and actuarial gains and losses included in net periodic benefit cost (see Note 13).

Other_Comprehensive_Income_Los3

Other Comprehensive Income (Loss) - Textual (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Pension plan net loss [Member]
Accumulated Other Comprehensive Income [Line Items]
Pension and other postretirement benefit plans net gain (loss), cost (credit) in AOCI	$3,500	$1,700
Other postretirement benefit plan net loss [Member]
Accumulated Other Comprehensive Income [Line Items]
Pension and other postretirement benefit plans net gain (loss), cost (credit) in AOCI	228	80
Pension plan prior service cost credit [Member]
Accumulated Other Comprehensive Income [Line Items]
Pension and other postretirement benefit plans net gain (loss), cost (credit) in AOCI	473	559
Other Postretirement Benefit Plan Prior Service Cost [Member]
Accumulated Other Comprehensive Income [Line Items]
Pension and other postretirement benefit plans net gain (loss), cost (credit) in AOCI	$257	$331

Segment_Reporting_Sales_of_Com

Segment Reporting - Sales of Company's Products (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Segment Reporting Information [Line Items]
Sales	$42,237		$44,033		$47,267
Revenue for the out-license of a pipeline compound			50
Forest Laboratories Inc [Member]
Segment Reporting Information [Line Items]
Proceeds from Sale of Intangible Assets	232
Other pharmaceutical [Member]
Segment Reporting Information [Line Items]
Sales	4,778	[1]	5,570	[1]	6,300	[1]
Pharmaceutical segment [Member]
Segment Reporting Information [Line Items]
Sales	36,042		37,437		40,601
Other segments [Member]
Segment Reporting Information [Line Items]
Sales	5,585	[2]	6,325	[2]	6,412	[2]
Operating segments [Member]
Segment Reporting Information [Line Items]
Sales	41,627		43,762		47,013
Other [Member]
Segment Reporting Information [Line Items]
Sales	610	[3]	271	[3]	254	[3]
Zetia [Member] \| Primary Care and Women's Health [Member]
Segment Reporting Information [Line Items]
Sales	2,650		2,658		2,567
Vytorin [Member] \| Primary Care and Women's Health [Member]
Segment Reporting Information [Line Items]
Sales	1,516		1,643		1,747
Januvia [Member] \| Primary Care and Women's Health [Member]
Segment Reporting Information [Line Items]
Sales	3,931		4,004		4,086
Janumet [Member] \| Primary Care and Women's Health [Member]
Segment Reporting Information [Line Items]
Sales	2,071		1,829		1,659
NuvaRing [Member] \| Primary Care and Women's Health [Member]
Segment Reporting Information [Line Items]
Sales	723		686		623
Implanon/Nexplanon [Member] \| Primary Care and Women's Health [Member]
Segment Reporting Information [Line Items]
Sales	502		403		348
Dulera [Member] \| Primary Care and Women's Health [Member]
Segment Reporting Information [Line Items]
Sales	460		324		207
Follistim AQ [Member] \| Primary Care and Women's Health [Member]
Segment Reporting Information [Line Items]
Sales	412		481		468
PegIntron [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	381		496		653
Victrelis [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	153		428		502
Isentress [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	1,673		1,643		1,515
Cancidas [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	681		660		619
Invanz [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	529		488		445
Noxafil [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	402		309		258
Bridion [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	340		288		261
Primaxin [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	329		335		384
Remicade [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	2,372		2,271		2,076
Simponi [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	689		500		331
Cosopt/Trusopt [Member] \| Hospital and Specialty [Member]
Segment Reporting Information [Line Items]
Sales	257		416		444
Emend [Member] \| Oncology [Member]
Segment Reporting Information [Line Items]
Sales	553		507		489
Temodar [Member] \| Oncology [Member]
Segment Reporting Information [Line Items]
Sales	350		708		917
Keytruda [Member] \| Oncology [Member]
Segment Reporting Information [Line Items]
Sales	55		0		0
Nasonex [Member] \| Diversified Brands [Member]
Segment Reporting Information [Line Items]
Sales	1,099		1,335		1,268
Singulair [Member] \| Diversified Brands [Member]
Segment Reporting Information [Line Items]
Sales	1,092		1,196		3,853
Clarinex [Member] \| Diversified Brands [Member]
Segment Reporting Information [Line Items]
Sales	232		235		393
Cozaar/Hyzaar [Member] \| Diversified Brands [Member]
Segment Reporting Information [Line Items]
Sales	806		1,006		1,284
Arcoxia [Member] \| Diversified Brands [Member]
Segment Reporting Information [Line Items]
Sales	519		484		453
Fosamax [Member] \| Diversified Brands [Member]
Segment Reporting Information [Line Items]
Sales	470		560		676
Propecia [Member] \| Diversified Brands [Member]
Segment Reporting Information [Line Items]
Sales	264		283		424
Zocor [Member] \| Diversified Brands [Member]
Segment Reporting Information [Line Items]
Sales	258		301		383
Remeron [Member] \| Diversified Brands [Member]
Segment Reporting Information [Line Items]
Sales	193		206		232
Gardasil [Member] \| Vaccines [Member]
Segment Reporting Information [Line Items]
Sales	1,738	[4]	1,831	[4]	1,631	[4]
ProQuad/M-M-R II/Varivax [Member] \| Vaccines [Member]
Segment Reporting Information [Line Items]
Sales	1,394	[4]	1,306	[4]	1,273	[4]
Zostavax [Member] \| Vaccines [Member]
Segment Reporting Information [Line Items]
Sales	765	[4]	758	[4]	651	[4]
Pneumovax 23 [Member] \| Vaccines [Member]
Segment Reporting Information [Line Items]
Sales	746	[4]	653	[4]	580	[4]
RotaTeq [Member] \| Vaccines [Member]
Segment Reporting Information [Line Items]
Sales	$659	[4]	$636	[4]	$601	[4]

[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 and Alliances, as well as Consumer Care until its divestiture on October 1, 2014 (see Note 4). The Alliances segment includes revenue from the Companyâ€™s relationship with AZLP until termination on June 30, 2014 (see Note 8).
[3]	Other revenues are primarily comprised of miscellaneous corporate revenues, including revenue hedging activities, sales related to divested products or businesses, and other supply sales not included in segment results. Other revenues in 2014 include $232 million received by Merck in connection with the sale of the U.S. marketing rights to Saphris (see Note 4). Other revenues in 2013 reflect $50 million of revenue for the out-license of a pipeline compound. Other revenues also include third-party manufacturing sales, a substantial portion of which was divested in October 2013 (see Note 3).
[4]	These amounts do not reflect sales of vaccines sold in most major European markets through the Companyâ€™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_Consolidated

Segment Reporting - Consolidated Revenues by Geographic Area (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Sales	$42,237	$44,033	$47,267
United States [Member]
Segment Reporting Information [Line Items]
Sales	17,071	18,246	20,392
Europe, Middle East, and Africa [Member]
Segment Reporting Information [Line Items]
Sales	13,174	13,140	12,990
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Sales	3,951	3,845	3,775
Japan [Member]
Segment Reporting Information [Line Items]
Sales	3,471	4,044	5,102
Latin America [Member]
Segment Reporting Information [Line Items]
Sales	3,151	3,203	3,389
Other [Member]
Segment Reporting Information [Line Items]
Sales	$1,419	$1,555	$1,619

Segment_Reporting_Reconciliati

Segment Reporting - Reconciliation of Segment Profits to Income Before Taxes (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Income Before Taxes	$17,283	$5,545	$8,739
Interest income	266	264	232
Interest expense	-732	-801	-714
Equity income from affiliates	257	404	642
Depreciation and amortization	-6,691	-6,988	-6,978
Research and development	-7,180	-7,503	-8,168
Restructuring costs	-1,013	-1,709	-664
Gain on divestiture of Merck Consumer Care	11,209	0	0
Gain on AstraZeneca option exercise	741	0	0
Loss on extinguishment of debt	-628	0	0
Net charge related to settlement of ENHANCE Litigation			-493
Pharmaceutical segment [Member]
Segment Reporting Information [Line Items]
Income Before Taxes	22,164	22,983	25,852
Equity income from affiliates	90	88	36
Depreciation and amortization	-39	-27	-25
Other segments [Member]
Segment Reporting Information [Line Items]
Income Before Taxes	2,546	3,094	3,163
Equity income from affiliates	108	475	504
Depreciation and amortization	-13	-22	-20
Operating segments [Member]
Segment Reporting Information [Line Items]
Income Before Taxes	24,710	26,077	29,015
Equity income from affiliates	198	563	540
Depreciation and amortization	-52	-49	-45
Other [Member]
Segment Reporting Information [Line Items]
Income Before Taxes	539	19	26
Unallocated [Member]
Segment Reporting Information [Line Items]
Interest income	266	264	232
Interest expense	-732	-801	-714
Equity income from affiliates	59	-159	102
Depreciation and amortization	-2,457	-2,250	-2,059
Research and development	-5,837	-6,381	-7,126
Amortization of purchase accounting adjustments	-4,182	-4,690	-4,872
Restructuring costs	-1,013	-1,709	-664
Gain on divestiture of Merck Consumer Care	11,209	0	0
Gain on AstraZeneca option exercise	741	0	0
Gain on the divestiture of certain ophthalmic products	480	0	0
Loss on extinguishment of debt	-628	0	0
Other unallocated, net	-5,872	-4,825	-4,708
Unallocated [Member] \| ENHANCE Litigation [Member]
Segment Reporting Information [Line Items]
Net charge related to settlement of ENHANCE Litigation	$0	$0	($493)

Segment_Reporting_Schedule_of_

Segment Reporting - Schedule of Equity Income from Affiliates and Depreciation and Amortization Included in Segment Profits (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Equity income from affiliates	$257	$404	$642
Depreciation and amortization	-6,691	-6,988	-6,978
Pharmaceutical [Member]
Segment Reporting Information [Line Items]
Equity income from affiliates	90	88	36
Depreciation and amortization	-39	-27	-25
All Other [Member]
Segment Reporting Information [Line Items]
Equity income from affiliates	108	475	504
Depreciation and amortization	-13	-22	-20
Total [Member]
Segment Reporting Information [Line Items]
Equity income from affiliates	198	563	540
Depreciation and amortization	($52)	($49)	($45)

Segment_Reporting_Property_Pla

Segment Reporting - Property, Plant and Equipment, Net by Geographic Area (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	$13,136	$14,973	$16,030
United States [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	8,727	10,076	10,687
Europe, Middle East, and Africa [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	3,120	3,346	3,688
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	897	1,001	1,059
Latin America [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	207	242	250
Japan [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	172	211	243
Other [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	$13	$97	$103

Segment_Reporting_Textual_Deta

Segment Reporting - Textual (Details)	12 Months Ended
	Dec. 31, 2014
	segment
Segment Reporting [Abstract]
Number of operating segments	3