Significant Accounting Policies	3 Months Ended
Mar. 31, 2018
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of Presentation. The accompanying unaudited condensed consolidated financial statements of Silgan Holdings Inc., or Silgan, have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the accompanying financial statements include all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation. The results of operations for any interim period are not necessarily indicative of the results of operations for the full year. The Condensed Consolidated Balance Sheet at December 31, 2017 has been derived from our audited consolidated financial statements at that date, but does not include all of the information and footnotes required by GAAP for complete financial statements. Deferred income taxes as of March 31, 2017 previously included in other liabilities have been presented as a separate line item on the Condensed Consolidated Balance Sheet to conform to current period presentation. You should read the accompanying condensed consolidated financial statements in conjunction with our consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2017. Stock Split. On May 3, 2017, our Board of Directors declared a two-for-one stock split of our issued common stock. The stock split was effected on May 26, 2017 in the form of a stock dividend. Stockholders of record at the close of business on May 15, 2017 were issued one additional share of common stock for each share of common stock owned on that date. Information pertaining to per share and share amounts have been retroactively adjusted in the Condensed Consolidated Statement of Income for the three months ended March 31, 2017. Recently Adopted Accounting Pronouncements. In May 2014, the Financial Accounting Standards Board, or FASB, issued an accounting standards update, or ASU, that amends the guidance for revenue recognition. This amendment contains principles that require an entity to recognize revenue to depict the transfer of promised goods and services to customers at an amount that an entity expects to be entitled to in exchange for those promised goods or services. We adopted this amendment on January 1, 2018, using the modified retrospective method. Results for the reporting period beginning January 1, 2018 are presented under the new guidance, while prior period amounts are not adjusted. The adoption of this amendment required us to accelerate the recognition of revenue prior to shipment to certain customers in cases where we produce promised goods with no alternative use to us and for which we have an enforceable right of payment for production completed. As a result of the adoption of this amendment, we increased trade accounts receivable, net by $69.4 million, decreased inventories by $56.6 million, increased accrued liabilities by $0.9 million and increased long-term deferred income tax liabilities by $2.8 million, resulting in a net increase to retained earnings of $9.1 million, all as of January 1, 2018. The adoption of this amendment did not have a material impact on our financial position, results of operations or cash flows. See Note 2 for further information. In August 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 the manner in which items are classified on the statement of cash flows as either operating, investing or financing activities. We have adopted this amendment as of January 1, 2018 using the retrospective approach. The adoption of this amendment did not have a material impact on our statement of cash flows. In March 2017, the FASB issued an ASU that amends the presentation of net periodic pension cost and net periodic postretirement benefit cost. This amendment requires an entity to disaggregate the service cost component from the other components of net periodic benefit cost, to report the service cost component in the same line item as other compensation costs and to report the other components of net periodic benefit cost (which include interest cost, expected return on plan assets, amortization of prior service cost or credit and actuarial gains and losses) separately. In addition, capitalization of net periodic benefit cost in assets is limited to the service cost component. We have adopted this amendment as of January 1, 2018. As a result of separately reporting the other components of net periodic benefit cost, we retrospectively increased cost of goods sold by $6.6 million, increased selling, general and administrative expenses by $1.7 million and reported other pension and postretirement income of $8.3 million in our Condensed Consolidated Statement of Income for the three months ended March 31, 2017 based on amounts previously included in net periodic benefit costs for retirement benefits as disclosed in Note 10. The adoption of this amendment did not have a material impact on our financial position, results of operations or cash flows. Recently Issued Accounting Pronouncements. In February 2016, the FASB issued an ASU that amends existing guidance for certain leases by lessees. This amendment will require an entity 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.

Significant Accounting Policies

Basis of Presentation. The accompanying unaudited condensed consolidated financial statements of Silgan Holdings Inc., or Silgan, have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP, for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the accompanying financial statements include all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation. The results of operations for any interim period are not necessarily indicative of the results of operations for the full year.

The Condensed Consolidated Balance Sheet at December 31, 2017 has been derived from our audited consolidated financial statements at that date, but does not include all of the information and footnotes required by GAAP for complete financial statements.

Deferred income taxes as of March 31, 2017 previously included in other liabilities have been presented as a separate line item on the Condensed Consolidated Balance Sheet to conform to current period presentation.

You should read the accompanying condensed consolidated financial statements in conjunction with our consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2017.

Stock Split. On May 3, 2017, our Board of Directors declared a two-for-one stock split of our issued common stock. The stock split was effected on May 26, 2017 in the form of a stock dividend. Stockholders of record at the close of business on May 15, 2017 were issued one additional share of common stock for each share of common stock owned on that date. Information pertaining to per share and share amounts have been retroactively adjusted in the Condensed Consolidated Statement of Income for the three months ended March 31, 2017.

Recently Adopted Accounting Pronouncements. In May 2014, the Financial Accounting Standards Board, or FASB, issued an accounting standards update, or ASU, that amends the guidance for revenue recognition. This amendment contains principles that require an entity to recognize revenue to depict the transfer of promised goods and services to customers at an amount that an entity expects to be entitled to in exchange for those promised goods or services. We adopted this amendment on January 1, 2018, using the modified retrospective method. Results for the reporting period beginning January 1, 2018 are presented under the new guidance, while prior period amounts are not adjusted. The adoption of this amendment required us to accelerate the recognition of revenue prior to shipment to certain customers in cases where we produce promised goods with no alternative use to us and for which we have an enforceable right of payment for production completed. As a result of the adoption of this amendment, we increased trade accounts receivable, net by $69.4 million, decreased inventories by $56.6 million, increased accrued liabilities by $0.9 million and increased long-term deferred income tax liabilities by $2.8 million, resulting in a net increase to retained earnings of $9.1 million, all as of January 1, 2018. The adoption of this amendment did not have a material impact on our financial position, results of operations or cash flows. See Note 2 for further information.

In August 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 the manner in which items are classified on the statement of cash flows as either operating, investing or financing activities. We have adopted this amendment as of January 1, 2018 using the retrospective approach. The adoption of this amendment did not have a material impact on our statement of cash flows.

In March 2017, the FASB issued an ASU that amends the presentation of net periodic pension cost and net periodic postretirement benefit cost. This amendment requires an entity to disaggregate the service cost component from the other components of net periodic benefit cost, to report the service cost component in the same line item as other compensation costs and to report the other components of net periodic benefit cost (which include interest cost, expected return on plan assets, amortization of prior service cost or credit and actuarial gains and losses) separately. In addition, capitalization of net periodic benefit cost in assets is limited to the service cost component. We have adopted this amendment as of January 1, 2018. As a result of separately reporting the other components of net periodic benefit cost, we retrospectively increased cost of goods sold by $6.6 million, increased selling, general and administrative expenses by $1.7 million and reported other pension and postretirement income of $8.3 million in our Condensed Consolidated Statement of Income for the three months ended March 31, 2017 based on amounts previously included in net periodic benefit costs for retirement benefits as disclosed in Note 10. The adoption of this amendment did not have a material impact on our financial position, results of operations or cash flows.

Recently Issued Accounting Pronouncements. In February 2016, the FASB issued an ASU that amends existing guidance for certain leases by lessees. This amendment will require an entity 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.