Description of the Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of presentation and principles of consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. GAAP. The accompanying consolidated financial statements include the accounts of SGC and its wholly owned subsidiaries, and those subsidiaries in which we have a controlling financial interest. Investments in other entities in which we do not have a controlling financial interest but we exert significant influence are accounted for in our consolidated financial statements using the equity method of accounting. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Cash and Cash Equivalents and Restricted Cash	Cash and cash equivalents Cash and cash equivalents include all cash balances and highly liquid investments with an original maturity of three months or less. We place our temporary cash investments with high credit quality financial institutions. At times, such investments in U.S. accounts may be in excess of the Federal Deposit Insurance Corporation insurance limit. Restricted cash We are required by gaming regulations to maintain sufficient reserves in restricted cash accounts to be used for the purpose of funding payments to WAP jackpot winners. Restricted cash balances are based primarily on the jackpot meters displayed to slot players or for previously won jackpots and vary by jurisdiction. Compliance with maintaining adequate restricted cash balances and complying with appropriate investment guidelines for jackpot funding is periodically reported to gaming authorities.
Minimum Guarantees	Minimum guarantees We enter into long-term license agreements with third parties in which we are obligated to pay a minimum guaranteed amount of royalties, typically annually over the life of the contract. These license agreements provide us with access to a portfolio of major brands to be used across our business segments in building our strong brand presence across multiple channels of distributions. We account for the minimum guaranteed obligations within accrued and other long-term liabilities at the onset of the license arrangement and record a corresponding licensed asset within intangible assets, net. The licensed intangible assets related to the minimum guaranteed obligations are amortized over the term of the license agreement with the amortization expense recorded in D&A. The long-term liability related to the minimum guaranteed obligations is reduced as royalty payments are made as required under the license agreement. We assess the recoverability of license agreements whenever events arise or circumstances change that indicate the carrying value of the licensed asset may not be recoverable. Recoverability of the licensed asset and the amount of impairment, if any, are determined using our policy for intangible assets with finite useful lives.
Other Assets	Other assets We capitalize debt issuance costs associated with long-term line-of-credit arrangements and amortize such amounts ratably over the term of the arrangement as an adjustment to interest expense. We assess the recoverability of our other long-term assets whenever events arise or circumstances change that indicate the carrying value of the asset may not be recoverable.
Advertising Costs	Advertising costs The cost of advertising is expensed as incurred and totaled $102.0 million, $82.6 million and $71.3 million in 2018, 2017 and 2016, respectively.
R&D	R&D R&D relates primarily to software product development costs and is expensed as incurred until technological feasibility has been established. Employee related costs associated with product development are included in R&D.
Foreign Currency Translation	Foreign currency translation We have significant operations where the local currency is the functional currency, including our operations in the U.K., Europe, Australia and Canada. Assets and liabilities of foreign operations are translated at period-end rates of exchange and results of operations are translated at the average rates of exchange for the period. Gains or losses resulting from translating the foreign currency financial statements are accumulated as a separate component of accumulated other comprehensive loss in stockholders’ deficit. Gains or losses resulting from foreign currency transactions are included in other (expense) income, net. See Note 20.
Comprehensive Loss	Comprehensive loss We include and classify in comprehensive loss unrealized gains and losses from our foreign currency translation adjustments, certain gains or losses associated with pension or other post-retirement benefits, including prior service costs or credits and transition assets or obligations, the effective portion of derivative financial instruments designated as hedging instruments, and net investment non-derivative hedge of our investments in certain of our international subsidiaries.
New Accounting Guidance	New Accounting Guidance - Recently Adopted In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers. ASU 2014-09 combined with all subsequent amendments (collectively, ASC 606) provides guidance outlining a single comprehensive revenue model in accounting for revenue from contracts with customers. ASC 606 supersedes existing revenue recognition guidance, including industry-specific guidance, and replaces it with a five-step revenue model with a core principle that “an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.” This guidance is effective for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years. We adopted this guidance effective January 1, 2018 using a modified retrospective application approach. See Note 3 for our revenue recognition policy and the adoption impact of ASC 606 on our consolidated financial statements. The FASB issued ASU No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business in 2017. The new guidance clarifies the definition of a business in order to allow for the evaluation of whether transactions should be accounted for as acquisitions or disposals of assets or businesses. We adopted this guidance effective January 1, 2018, and this adoption did not have a material effect on our consolidated financial statements. The FASB issued ASU No. 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost in 2017. We adopted this guidance effective January 1, 2018. This guidance requires an employer to report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. The other components of net benefit cost are required to be presented in the income statement separately from the service cost component and outside a subtotal of operating income, if one is presented, which for us means that certain immaterial amounts are classified within interest expense as compared to the previous classification within SG&A. We are also required to describe which line items are used to present the other components of net benefit cost if such financial statement line items are separately presented; otherwise, we must disclose the line items in which such costs are presented. The FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities in 2017. We early adopted this guidance during the first quarter of 2018, which simplifies the application of hedge accounting guidance, and creates greater transparency for results presented on the face of the financial statements and footnotes. Our adoption did not have a material effect on our consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, which aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This guidance requires that such capitalized implementation costs for hosting arrangements are expensed over the term of the hosting arrangement and presented in the same line item in the statement of operations and comprehensive (loss) income as the fees associated with the hosting service. We early adopted this guidance prospectively effective the third quarter of 2018, and this adoption did not have a material effect on our consolidated financial statements. New Accounting Guidance - Not Yet Adopted The FASB issued ASU No. 2016-02, Leases (Topic 842) in 2016. ASU 2016-02 combined with all subsequent amendments (collectively, ASC 842) requires balance sheet recognition for all leases with a lease term greater than one year to be recorded as a lease liability (on a discounted basis) with a corresponding right-of-use asset. This guidance also expands the required quantitative and qualitative disclosures for lease arrangements and gives rise to other changes impacting certain aspects of lessor accounting. We will adopt this guidance at the beginning of the first quarter of 2019 using the optional transition method provided by ASU 2018-11, and we anticipate applying both the lessee package of practical expedients and the available lessor practical expedients. We have substantially completed our assessment and the following is our adoption impact assessment completed to date: Lessee Accounting: We estimate the adoption will result in the addition of $115.0 million to $145.0 million of assets and liabilities to our consolidated balance sheet, primarily related to real estate leases, with no significant change to our consolidated statements of operations and comprehensive (loss) income or cash flows. We also expect our quantitative and qualitative disclosures for lease arrangements to increase under ASC 842. Lessor Accounting: Certain of our international gaming operations arrangements and domestic lottery systems arrangements may contain identified equipment that is conveyed to our customers as a part of a comprehensive service solution. The equipment substitution rights under these arrangements are concluded to be non-substantive, because historical substitutions have primarily been made for operational failures or maintenance reasons and such substitutions generally do not provide us an economic benefit due to high capital costs without incremental revenue. We do not anticipate this fact pattern will change in the future; accordingly, we expect to treat such arrangements as a service arrangement with an embedded lease. However, because the lease component of such lottery arrangements generally is not predominant, we anticipate recognizing the associated revenue under these arrangements under ASC 606. While most of these arrangements are expected to contain embedded operating leases, depending on the terms of these arrangements, either at inception or upon modification, certain of these arrangements could potentially be classified as sales-type financing leases. Because we are predominantly compensated on a variable basis based on a percentage of revenue in these arrangements, we might be required to recognize a loss at lease inception (or modification) for such arrangements classified as sales-type financing leases. This loss would result from the derecognition of the carrying amount of the underlying equipment that is greater than the net investment in the lease, even though the arrangement is expected to ultimately be profitable. This is not expected to change the timing or amount of revenue that we recognize under these arrangements. The FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326) in 2016. The new guidance replaces the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. For trade and other receivables, loans and other financial instruments, we will be required to use a forward-looking expected loss model rather than the incurred loss model for recognizing credit losses which reflects losses that are probable. The new guidance will be effective for us beginning January 1, 2020, with early adoption permitted beginning January 1, 2019. Application is through a cumulative-effect adjustment to retained earnings as of the effective date. We are currently evaluating the impact of adopting this guidance. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement. The new guidance amends the disclosure requirements for recurring and nonrecurring fair value measurements by removing, modifying, and adding certain disclosures on fair value measurements in ASC 820. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. The new guidance will be effective for us beginning January 1, 2020, with early adoption permitted upon issuance of this updated guidance. We do not plan to early adopt this ASU, and we are currently evaluating the impact of adopting this guidance. We do not expect that any other recently issued accounting guidance will have a significant effect on our consolidated financial statements.
Revenue and Revenue Recognition	We evaluate the recognition of revenue and rental income based on the criteria set forth in ASC 606 or ASC 840, as appropriate. Revenue is recognized when control of the promised goods or services is transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for those goods or services. This condition normally is met when the product has been delivered or upon performance of services. Revenue is reported net of incentive rebates and discounts. We made an accounting policy election to exclude from the measurement of the transaction price sales taxes and all other items of a similar nature, and also elected to account for shipping and handling activities as a fulfillment of our promise to transfer the goods. Accordingly, shipping and handling costs are included in cost of sales. Our credit terms are predominately short term in nature. We also grant extended payment terms under certain Gaming contracts, primarily where the sale is secured by the related equipment sold. For these contracts with customers for which the financing component is determined to be significant to the contract, the contract transaction price is adjusted for the effect of a financing component (time value of money). We have not applied the significant financing component guidance to transactions with financing terms of 12 months or less. Any sales commissions associated with the sale or placement of our products and services are expensed as incurred as contracts associated with sales commissions are generally completed within a one-year period. The primary types of revenue impacted by the adoption of ASC 606 were Gaming operations and Lottery instant products. Each of these is described separately below. We had other balance sheet adoption impacts that, combined with the preceding, resulted in a net increase to opening accumulated loss of $10.9 million as of January 1, 2018. As part of the adoption of ASC 606, we increased contract liabilities by $9.7 million primarily associated with Lottery instant products licensing and player loyalty contracts for which we determined that the promises in the related contracts were part of a single performance obligation under ASC 606. In addition, we reduced previously recorded deferred costs net of newly established contract assets by $11.4 million related to licensing in certain customized lottery software contracts for which we concluded that we were unable to recognize revenue for delivered elements under ASC 985-605 due to the lack of vendor-specific objective evidence for undelivered elements and for which we were required to estimate the standalone selling price of delivered performance obligations under ASC 606. Other than the adoption impact for Gaming operations and Lottery instant products, described herein, the impact of adopting the new revenue recognition guidance on revenue and operating income in aggregate was less than $10.0 million. Contracts with Customers with Multiple Promised Goods and Services We enter into contracts with customers that include multiple promises (such as gaming machines, gaming systems hardware and software, installation, service and maintenance, product support or lottery systems and hardware, installation and maintenance bundled promises). For such contracts, the transaction price is allocated to each distinct performance obligation using an estimate of stand-alone selling price. The stand-alone selling price is generally based on observable prices or a cost plus margin approach. The establishment of stand-alone selling price requires judgment as to whether there is a sufficient quantity of items sold or substantively renewed on a stand-alone basis and those prices demonstrate an appropriate level of concentration to conclude that a stand-alone selling price exists. The guidance in ASC 606 requires that we apply judgments or estimates to determine both the performance obligations and the stand-alone selling prices of identified performance obligations. Contracts with multiple promised goods and services described above will often involve significant judgment in determining whether each promise is distinct or should be combined with other promises in such contracts in concluding on the distinct performance obligations for such contracts. Such judgment generally requires an assessment of the level of integration and interdependency between individual components particularly in our gaming systems and certain digital contracts with customers. Associated with these same contracts, we also apply significant judgment to determine the stand-alone selling prices of the identified performance obligations. In certain contracts with customers, we bundle the selling price for multiple promised goods or services or we may license systems for which the solutions we provide are highly customized and therefore the prices we charge are either uncertain, highly variable, or both. Gaming Operations Gaming operations revenues are generated by providing customers access to proprietary land-based gaming equipment, table game products and VLTs under a variety of recurring operating, service, or rental contracts, for which consideration is based upon a percentage of Coin-in, a percentage of Net win, or a fixed daily/monthly fee, with variability generally resolved in the reporting period. For these contracts with customers, we generally transfer control and recognize revenue or rental income over time based on the amount we expect to receive as described and classify such revenue or rental income as services revenue. Payments from customers under these contracts are typically due on a monthly basis. Jackpot expense for our WAP services is recorded as a reduction to revenue, which decreased revenue and cost of services by $22.3 million for the year ended December 31, 2018. This change in classification has no impact on operating income or net loss. There was $23.2 million and $29.8 million of such amounts presented as cost of services for the year ended December 31, 2017 and 2016. The amount of rental income revenue that is outside the scope of ASC 606 and ASC 605 was $265.2 million, $275.0 million, and $294.3 million for the years ended December 31, 2018, 2017 and 2016, respectively. Gaming Machine Sales These contracts with customers include the sale of gaming machines, including game content, electronic table game products and parts (including game themes and conversion kits). We transfer control and recognize revenue from the sale of gaming machines at a point in time upon delivery of gaming machines to our customers or distributors pursuant to the terms of the contract. If the sale of gaming machines includes multiple promised goods and services, these contracts are accounted for as described in the “Contracts with Customers with Multiple Promised Goods and Services” section above. Our credit terms are predominately short term in nature. Gaming Systems Gaming systems contracts with customers can include a comprehensive suite of technology solutions provided to gaming operators, including perpetual licenses to core system solutions and non-core system solutions and other applications and tools. Gaming systems products also include the iVIEW touch screen display, which facilitates the player experience, bonus features, customer service, and employee functions and ongoing hardware and software maintenance services and upgrades. Determination of performance obligations and timing of the transfer of control varies by contract. Generally, these contracts contain multiple promised goods and services, including the following: (i) core system software license; (ii) non-core system software license(s); (iii) professional services; (iv) system-based hardware; (v) in-game hardware products; and (vi) software and hardware maintenance and product support. Control transfers and we recognize revenue from the sale of perpetual gaming systems licenses and various hardware products at a point in time when the gaming system is available for use by a customer which is no earlier than the commencement of the license term, and for the hardware products upon delivery. For contracts that include new core gaming system installations, control is not considered transferred until control of the core gaming system license is transferred as the additional promises are generally highly dependent on the core gaming system. Software and hardware maintenance and product support services are considered stand-ready obligations, therefore control transfers and revenue is recognized over time over the term of the maintenance and support period. If a gaming systems contract includes multiple promised goods and services, these contracts are accounted for as described in the “Contracts with Customers with Multiple Promised Goods and Services” section above. Table Products Table products revenue is generated from supplying and maintaining or selling table game products, primarily including automatic card shufflers, deck checkers, table roulette chip sorters and other land-based table gaming equipment. We transfer control and recognize revenue from the sale of table products at a point in time upon delivery to our customers or distributors pursuant to the terms of the contract. Supply and maintenance contracts, for which consideration is primarily based on a fixed monthly fee, are considered stand-ready obligations, therefore control transfers and revenue is recognized over time over the term of the supply and maintenance period. Such contracts are generally short-term in nature. We also license our proprietary table games content, for which revenue is recognized at a point in time under the licensing of intellectual property guidance as such licenses are functional licenses. Lottery Instant Products Our instant products revenue is primarily generated under long-term contracts to supply instant products and provide related services to our Lottery customers. For instant products that are sold on a PPU and POS basis, we generally have a single performance obligation of a promise to supply the instant products. Control transfers and we recognize revenue from the sale of such instant products when the lotteries have taken delivery of shipments of instant products pursuant to the terms of the contract. For instant products that are sold on a POS basis, we are compensated based on retail sales, therefore the timing difference between the recognition of revenue, the billing of our customers and the receipt of payments depends on retail sales. Contract assets resulting from these contracts remain until we have the contractual ability to invoice and collect from customers (which occurs upon retail sales). For our CSP contracts, revenue is recognized when a lottery retailer activates associated instant tickets, which timing corresponds with how we satisfy our performance obligation. The guidance in ASC 606 requires that we apply judgment to determine the timing of control transfer of performance obligations in our Lottery instant products contracts. For instant products that are sold under POS contracts, we generally have a single performance obligation of a promise to supply the instant products. The determination of when control transfers requires significant judgment because lotteries take delivery of shipments of instant products, but we retain the risk of such inventory until retail sales of such tickets takes place. We have determined control transfers upon delivery to a lottery-controlled warehouse, because we do not have the ability to direct the use of such instant products subsequent to delivery. Lottery revenue associated with instant products sold on a POS basis increased by less than $5.0 million for the year ended December 31, 2018 as a result of adopting the new revenue recognition guidance. The revenue value of tickets and the associated historical cost of inventory sold under POS arrangements remaining in the distribution channel at December 31, 2017 was reflected directly in shareholders’ deficit with an increase to contract assets (included in Prepaid expenses, deposits and other current assets) totaling $52.0 million, a reduction to inventory totaling $33.0 million and a decrease to accumulated net loss totaling $19.0 million. The impact of ASC 606 on our December 31, 2018 consolidated balance sheet was a $36.5 million decrease to inventories and a $64.3 million increase to contract assets included in Prepaid expenses, deposits and other current assets. Lottery Systems Our Lottery business segment offers our customers a number of related, value-added services as part of an integrated product offering. These services include lottery systems, including point-of-sale terminals and other equipment, software, data communication services and support and instant game validation systems, and software, hardware and related services for sports wagering and keno systems. For our integrated lottery systems service contracts (described above), our single performance obligation is a promise to perform a series of stand-ready services to operate a fully-functional draw lottery. Revenue is recognized over time in an amount generally based on a percentage of sales of the related games, which represents our measure of progress toward satisfying our performance obligation. For our perpetual licensing of customized lottery software contracts, we generally recognize revenue over time using costs incurred to date relative to total estimated completion costs to measure progress toward satisfying our performance obligations, which we believe best depicts the transfer of control to the customer. Maintenance on lottery software and lottery terminals is considered a stand-ready obligation, with control transferring and revenue being recognized over time ratably over the maintenance and support period. If a lottery systems contract includes multiple promised goods and services, these contracts are accounted for as described in the “Contracts with Customers with Multiple Promised Goods and Services” section above. Social Gaming Social gaming revenues are generated from the sale of virtual coins, chips or bingo cards (collectively referred to as “virtual currency”), which players can use to play casino-style slot and table games or bingo games (i.e., spin in the case of slot games, bet in the case of table games and use of bingo cards in the case of bingo games). We distribute our games through various global social web and mobile platforms such as Facebook, Apple, Google, Amazon, and other web and mobile platforms. Control transfers and we recognize revenues from player purchases of virtual currency as the virtual currency is consumed for game play, which is based on a historical data analysis. Because we have control over the content and functionality of games before they are accessed by the end user, we have determined we are the principal and, as a result, revenues are recorded on a gross basis. Payment processing fees paid to platform providers (such as Facebook, Apple, Amazon and Google) are recorded within cost of services. All social gaming revenue is classified as services revenue. Digital Digital revenue is generated from professional services related to highly customized software design, development, licensing, maintenance and support services associated with a comprehensive suite of technology solutions, including sports books and betting markets across both fixed-odds and pari-mutuel betting styles. Additionally, through our integrated suite of various platform and technology solutions, we provide gaming operators optional portals for reporting and administrative functions, and access to a wide portfolio of content, including casino, lottery and bingo style games. Determination of performance obligations and timing of the transfer of control vary based on the nature of the contract. Generally, these contracts contain multiple promises, including the following: (i) implementation of customized software solution and the associated software license; (ii) support services and unspecified software updates; (iii) professional development services; and (iv) access to the game content. Control generally transfers and we recognize revenue from the implementation of a customized software solution and the associated software license over time using costs incurred to date relative to total estimated completion costs to measure progress toward satisfying our performance obligations, which we believe best depicts the transfer of control to the customer. Support services and unspecified software updates are considered stand-ready obligations, therefore control transfers and revenue is recognized over time ratably over the term of the support period. Professional development services generally relate to post-go live development, and control transfers and revenue is recognized over time as services are rendered. We also generate revenue from various content aggregation platforms, remote gaming servers, our SG Universe platform and various other platforms, which deliver a wide spectrum of internally developed and branded games and popular third-party provided games to gaming operators. We provide daily access to these platforms and are typically compensated based on variable consideration, such as a percentage of net gaming revenue with variability generally resolved in the reporting period. Substantially all Digital revenue is classified as services revenue.