Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2016
Accounting Policies [Abstract]
Nature of Business	Nature of Business. Silgan Holdings Inc., or Silgan, and its subsidiaries conduct business in three market segments: metal containers, closures and plastic containers. Our metal container business is engaged in the manufacture and sale of steel and aluminum containers for human and pet food and general line products. Our closures business manufactures and sells metal, composite and plastic closures for food and beverage products. Our plastic container business manufactures and sells custom designed plastic containers and closures for personal care, food, health care, pharmaceutical, household and industrial chemical, pet care, agricultural, automotive and marine chemical products. Our metal container business has operating facilities in North America, Europe and Asia. Our closures business has operating facilities in North and South America, Europe and Asia. Our plastic container business is based in North America.
Basis of Presentation	Basis of Presentation. The consolidated financial statements include the accounts of Silgan and our subsidiaries. Newly acquired subsidiaries have been included in the consolidated financial statements from their dates of acquisition. All significant intercompany transactions have been eliminated. The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles, or GAAP, requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results may differ from those estimates.
Foreign Currency Transactions and Translations Policy	Generally, our subsidiaries that operate outside the United States use their local currency as the functional currency. The principal functional currencies for our foreign operations are the Euro and the Canadian dollar. Balance sheet accounts of our foreign subsidiaries are translated at exchange rates in effect at the balance sheet date, while revenue and expense accounts are translated at average rates prevailing during the year. Translation adjustments are reported as a component of accumulated other comprehensive loss. Gains or losses resulting from transactions denominated in foreign currencies that are not designated as a hedge are included in selling, general and administrative expenses in our Consolidated Statements of Income.
Cash and Cash Equivalents	Cash and Cash Equivalents. Cash equivalents represent short-term, highly liquid investments which are readily convertible to cash and have maturities of three months or less at the time of purchase. As a result of our cash management system, checks issued for payment may create negative book balances. Checks outstanding in excess of related book balances are included in trade accounts payable in our Consolidated Balance Sheets. Changes in outstanding checks are included in financing activities in our Consolidated Statements of Cash Flows to treat them as, in substance, cash advances.
Inventories	Inventories. Inventories are valued at the lower of cost or market (net realizable value). Cost for domestic inventories for our metal container and closures businesses is principally determined on the last-in, first-out basis, or LIFO. Cost for inventories for our plastic container business is principally determined on the first-in, first-out basis, or FIFO. Cost for foreign inventories for our metal container and closures businesses is principally determined on the average cost method.
Property, Plant and Equipment, Net	Property, Plant and Equipment, Net. Property, plant and equipment, net is stated at historical cost less accumulated depreciation. Major renewals and betterments that extend the life of an asset are capitalized and repairs and maintenance expenditures are charged to expense as incurred. Design and development costs for molds, dies and other tools that we do not own and that will be used to produce products that will be sold under long-term supply arrangements are capitalized. Depreciation is computed using the straight-line method over the estimated useful lives of depreciable assets. The principal estimated useful lives are 35 years for buildings and range between 3 years to 20 years for machinery and equipment. Leasehold improvements are amortized over the shorter of the life of the related asset or the life of the lease. Interest incurred on amounts borrowed in connection with the installation of major machinery and equipment acquisitions is capitalized. Capitalized interest of $1.5 million, $1.0 million and $0.4 million in 2016, 2015 and 2014, respectively, was recorded as part of the cost of the assets to which it relates and is amortized over the assets’ estimated useful life.
Goodwill and Other Intangible Assets, Net	Goodwill and Other Intangible Assets, Net. We review goodwill and other indefinite-lived intangible assets for impairment as of July 1 of each year and more frequently if circumstances indicate a possible impairment. We determined that goodwill and other indefinite-lived intangible assets were not impaired in our annual assessment performed during the third quarter. Definite-lived intangible assets are amortized over their estimated useful lives on a straight-line basis. Customer relationships have a weighted average life of approximately 18 years. Other definite-lived intangible assets consist primarily of a trade name and technology know-how and have a weighted average life of approximately 8 years.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets. We assess long-lived assets, including intangible assets with definite lives, for impairment whenever events or changes in circumstances indicate the carrying amount of the assets may not be fully recoverable. An impairment exists if the estimate of future undiscounted cash flows generated by the assets is less than the carrying value of the assets. If impairment is determined to exist, any related impairment loss is then measured by comparing the fair value of the assets to their carrying amount.
Hedging Instruments	Hedging Instruments. All derivative financial instruments are recorded in the Consolidated Balance Sheets at their fair values. Changes in fair values of derivatives are recorded in each period in earnings or other comprehensive loss, depending on whether a derivative is designated as part of a hedge transaction and, if it is, the type of hedge transaction. We utilize certain derivative financial instruments to manage a portion of our interest rate and natural gas cost exposures. We do not engage in trading or other speculative uses of these financial instruments. For a financial instrument to qualify as a hedge, we must be exposed to interest rate or price risk, and the financial instrument must reduce the exposure and be designated as a hedge. Financial instruments qualifying for hedge accounting must maintain a high correlation between the hedging instrument and the item being hedged, both at inception and throughout the hedged period. We utilize certain internal hedging strategies to minimize our foreign currency exchange rate risk. Net investment hedges that qualify for hedge accounting result in the recognition of foreign currency gains or losses, net of tax, in accumulated other comprehensive loss. We generally do not utilize external derivative financial instruments to manage our foreign currency exchange rate risk.
Income Taxes	Income Taxes. We account for income taxes using the liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period of enactment of such change. No provision is made for U.S. income taxes applicable to undistributed earnings of foreign subsidiaries that are indefinitely reinvested.
Revenue Recognition	Revenue Recognition. Revenues are recognized when goods are shipped and the title and risk of loss pass to the customer. For those sites where we operate within the customer’s facilities, title and risk of loss pass to the customer upon delivery of product to clearly delineated areas within the common facility, at which time we recognize revenues. Shipping and handling fees and costs incurred in connection with products sold are recorded in cost of goods sold in our Consolidated Statements of Income.
Stock-Based Compensation	Stock-Based Compensation. We currently have one stock-based compensation plan in effect under which we have issued stock options and restricted stock units to our officers, other key employees and outside directors. A restricted stock unit represents the right to receive one share of our common stock at a future date. Unvested restricted stock units that have been issued do not have voting rights and may not be disposed of or transferred during the vesting period.
New Accounting Pronouncements	Recently Adopted Accounting Pronouncements. In July 2015, the Financial Accounting Standards Board, or the FASB, issued an accounting standards update, or ASU, that amends existing guidance for measuring inventories. This amendment requires us to measure inventories recorded using the first-in, first-out method and the average cost method at the lower of cost and net realizable value. This amendment did not change the methodology for measuring inventories recorded using the last-in, first-out method. As permitted, we have adopted this amendment early, effective January 1, 2016, and have applied it prospectively. The adoption of this amendment did not have a material effect on our financial position, results of operations or cash flows. In March 2016, the FASB issued an ASU that amends the guidance for stock compensation accounting. This amendment (i) requires all income tax effects of stock-based compensation awards to be recognized in the statement of income when such awards vest or are settled, (ii) allows an employer to repurchase more of an employee's shares upon the vesting or settlement of an award than it could have previously for tax withholding purposes without triggering liability accounting, (iii) allows an employer to make a policy election to recognize forfeitures in respect of awards as they occur and (iv) specifies certain classifications on the statement of cash flows related to excess tax benefits and shares repurchased from employees for tax withholding purposes. As permitted, we have adopted this amendment early, effective January 1, 2016, and have applied it (i) prospectively as it related to recognizing income tax effects of awards in the statement of income, (ii) using the modified retrospective method as it related to classifying certain awards as equity rather than liabilities and recognizing forfeitures as they occur and (iii) using the retrospective method as it related to classifying excess tax benefits on the statement of cash flows. The adoption of this amendment did not have a material effect on our financial position, results of operations or cash flows. Recently Issued Accounting Pronouncements. In May 2014, the FASB issued an ASU that amends the guidance for revenue recognition. This amendment contains principles that will require an entity to recognize revenue to depict the transfer of goods and services to customers at an amount that an entity expects to be entitled to in exchange for those goods or services. This amendment permits the use of one of two retrospective transition methods. We will adopt this amendment on January 1, 2018, and we have not yet selected a transition method. The adoption of this amendment may require us to accelerate the recognition of revenue as compared to the current standards for certain customers in cases where we produce products unique to those customers and for which we would have an enforceable right of payment for production completed to date. We will continue to assess the impact of this amendment on our financial position, results of operations and cash flows. In February 2016, the FASB issued an ASU that amends existing guidance for certain leases by lessees. This amendment will require us to recognize assets and liabilities on the balance sheet for the rights and obligations created by long-term leases and to disclose additional quantitative and qualitative information about leasing arrangements. In addition, this amendment clarifies the presentation requirements of the effects of leases in the statement of income and statement of cash flows. This amendment will be effective for us on January 1, 2019. Early adoption is permitted. This amendment is required to be adopted using a modified retrospective approach. We are currently evaluating the impact of this amendment on our financial position, results of operations and cash flows. In August of 2016, the FASB issued an ASU that provides guidance for cash flow classification for certain cash receipts and cash payments to address diversity in practice in how items are classified on the statement of cash flows as either operating, investing or financing activities. This amendment will be effective for us on January 1, 2018. Early adoption is permitted. This amendment is required to be adopted using a retrospective approach. We are currently evaluating the impact of this amendment on our statement of cash flows. In January 2017, the FASB issued an ASU that provides guidance to simplify the test for goodwill impairment. This guidance eliminates the requirement to assign the fair value of a reporting unit to each of its assets and liabilities to quantify a goodwill impairment charge. Under this amended guidance, the goodwill impairment charge to be recognized will be determined based on comparing the carrying value of the reporting unit to its fair value. This amendment will be effective for us on January 1, 2020. Early adoption is permitted, and we plan to adopt this amendment when we perform our first goodwill impairment test after January 1, 2017. This amendment is required to be adopted prospectively and is not expected to have a significant impact on our financial position, results of operations or cash flows.