Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies As described in Note 3, effective January 1, 2018 the company adopted the requirements of ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), using the modified retrospective method. See below for the company’s updated revenue recognition accounting policy. Revenue recognition Revenue is recognized at an amount that reflects the consideration to which the company expects to be entitled in exchange for transferring goods and services to a customer. The company determines revenue recognition using the following five steps: (1) identify the contract(s) with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when (or as) the company satisfies a performance obligation. Revenue excludes taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction and collected by the company from a customer (e.g., sales, use and value added taxes). Revenue includes payments for shipping and handling activities. At contract inception, the company assesses the goods and services promised in a contract with a customer and identifies as a performance obligation each promise to transfer to the customer either: (1) a good or service (or a bundle of goods or services) that is distinct or (2) a series of distinct goods or services that are substantially the same and that have the same pattern of transfer to the customer. The company recognizes revenue only when it satisfies a performance obligation by transferring a promised good or service to a customer. The company must apply its judgment to determine the timing of the satisfaction of performance obligations as well as the transaction price and the amounts allocated to performance obligations including estimating variable consideration, adjusting the consideration for the effects of the time value of money and assessing whether an estimate of variable consideration is constrained. Revenue from hardware sales is recognized upon the transfer of control to a customer, which is defined as an entity’s ability to direct the use of and obtain substantially all of the remaining benefits of an asset. Revenue from software licenses is recognized at the inception of either the initial license term or the inception of an extension or renewal to the license term. Revenue for operating leases is recognized on a monthly basis over the term of the lease and for sales-type leases at the inception of the lease term. Revenue from equipment and software maintenance and post-contract support is recognized on a straight-line basis as earned over the terms of the respective contracts. Cost related to such contracts is recognized as incurred. Revenue and profit under systems integration contracts are recognized over time as the company transfers control of goods or services. The company measures its progress toward satisfaction of its performance obligations using the cost-to-cost method, or when services have been performed, depending on the nature of the project. For contracts accounted for using the cost-to-cost method, revenue and profit recognized in any given accounting period are based on estimates of total projected contract costs. The estimates are continually reevaluated and revised, when necessary, throughout the life of a contract. Any adjustments to revenue and profit resulting from changes in estimates are accounted for in the period of the change in estimate. When estimates indicate that a loss will be incurred on a contract upon completion, a provision for the expected loss is recorded in the period in which the loss becomes evident. Revenue from time and materials service contracts and outsourcing contracts is recognized as the services are provided using either an objective measure of output or on a straight-line basis over the term of the contract. The company also enters into multiple-element arrangements, which may include any combination of hardware, software or services. For example, a client may purchase an enterprise server that includes operating system software. In addition, the arrangement may include post-contract support for the software and a contract for post-warranty maintenance for service of the hardware. These arrangements consist of multiple performance obligations, with control over hardware and software transferred in one reporting period and the software support and hardware maintenance services performed across multiple reporting periods. In another example, the company may provide desktop managed services to a client on a long-term multiple-year basis and periodically sell hardware and license software products to the client. The services are provided on a continuous basis across multiple reporting periods and control over the hardware and software products occurs in one reporting period. To the extent that a performance obligation in a multiple-deliverable arrangement is subject to specific guidance, that performance obligation is accounted for in accordance with such specific guidance. An example of such an arrangement may include leased assets which are subject to specific leasing accounting guidance. In multiple-element arrangements, the company allocates the total transaction price to be earned under the arrangement among the various performance obligations in proportion to their standalone selling prices (relative standalone selling price basis). The standalone selling price for a performance obligation is the price at which the company would sell a promised good or service separately to a customer. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. Many of the company’s contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and, therefore, not distinct. For contracts with multiple performance obligations, the company allocates the contract’s transaction price to each performance obligation using its best estimate of the standalone selling price of each distinct good or service in the contract. The primary methods used to estimate standalone selling price are as follows: (1) the expected cost plus margin approach, under which the company forecasts its expected costs of satisfying a performance obligation and then adds an appropriate margin for that distinct good or service and (2) the percent discount off of list price approach. In the Services segment, substantially all of the company’s performance obligations are satisfied over time as work progresses and therefore substantially all of the revenue in this segment is recognized over time. The company generally receives payment for these contracts over time as the performance obligations are satisfied. In the Technology segment, substantially all of the company’s goods and services are transferred to customers at a single point in time. Revenue on these contracts is recognized when control over the product is transferred to the customer or a software license term begins. The company generally receives payment for these contracts upon signature or within 30 to 60 days. At March 31, 2018, the company had approximately $1.5 billion of remaining performance obligations of which approximately 50% is estimated to be recognized as revenue by the end of 2019. The company does not disclose the value of unsatisfied performance obligations for (1) contracts with an original expected length of one year or less and (2) contracts for which the company recognizes revenue at the amount to which it has the right to invoice for services performed. The company discloses disaggregation of its customer revenue by geographic areas and by classes of similar products and services, by segment (see Note 15). The timing of revenue recognition, billings and cash collections results in billed accounts receivables, unbilled receivables, contract assets and deferred revenue (contract liabilities). The disclosure of contract assets is a new requirement due to the adoption of Topic 606. At December 31, 2017, contract assets were included in accounts receivables, net on the company’s Consolidated Balance Sheet. At March 31, 2018, $6.0 million of long-term contract assets were included in other long-term assets on the company’s Consolidated Balance Sheet. Significant changes during the three months ended March 31, 2018 in the above contract asset and liability balances were as follows: revenue of $104.6 million was recognized that was included in deferred revenue at December 31, 2017. The company’s incremental direct costs of obtaining a contract consist of sales commissions which are deferred and amortized ratably over the initial contract life. These costs are classified as current or noncurrent based on the timing of when the company expects to recognize the expense. The current and noncurrent portions of deferred commissions are included in prepaid expenses and other current assets and in other long-term assets, respectively, in the company’s Consolidated Balance Sheets. At March 31, 2018 and December 31, 2017, the company had $10.1 million and $11.0 million, respectively, of deferred commissions. For the three months ended March 31, 2018, $1.7 million of amortization expense related to deferred commissions was recorded in selling, general and administrative expense in the company’s Consolidated Statement of Income. Costs to fulfill a contract, which are incurred upon initiation of certain services contracts and are related to initial customer setup, are included in outsourcing assets, net in the company’s Consolidated Balance Sheet. The amount of such cost at March 31, 2018 and December 31, 2017 was $77.1 million and $76.0 million, respectively. These costs are amortized over the initial contract life and reported in services cost of sales. During the three months ended March 31, 2018, $3.6 million was amortized. Recoverability of these costs are subject to various business risks. Quarterly, the company compares the carrying value of these assets with the undiscounted future cash flows expected to be generated by them to determine if there is impairment. If impaired, these assets are reduced to an estimated fair value on a discounted cash flow basis. The company prepares its cash flow estimates based on assumptions that it believes to be reasonable but are also inherently uncertain. Actual cash flows could differ from these estimates.

Summary of Significant Accounting Policies

As described in Note 3, effective January 1, 2018 the company adopted the requirements of ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), using the modified retrospective method. See below for the company’s updated revenue recognition accounting policy.

Revenue recognition

Revenue is recognized at an amount that reflects the consideration to which the company expects to be entitled in exchange for transferring goods and services to a customer. The company determines revenue recognition using the following five steps: (1) identify the contract(s) with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue when (or as) the company satisfies a performance obligation.

Revenue excludes taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction and collected by the company from a customer (e.g., sales, use and value added taxes). Revenue includes payments for shipping and handling activities.

At contract inception, the company assesses the goods and services promised in a contract with a customer and identifies as a performance obligation each promise to transfer to the customer either: (1) a good or service (or a bundle of goods or services) that is distinct or (2) a series of distinct goods or services that are substantially the same and that have the same pattern of transfer to the customer. The company recognizes revenue only when it satisfies a performance obligation by transferring a promised good or service to a customer.

The company must apply its judgment to determine the timing of the satisfaction of performance obligations as well as the transaction price and the amounts allocated to performance obligations including estimating variable consideration, adjusting the consideration for the effects of the time value of money and assessing whether an estimate of variable consideration is constrained.

Revenue from hardware sales is recognized upon the transfer of control to a customer, which is defined as an entity’s ability to direct the use of and obtain substantially all of the remaining benefits of an asset.

Revenue from software licenses is recognized at the inception of either the initial license term or the inception of an extension or renewal to the license term.

Revenue for operating leases is recognized on a monthly basis over the term of the lease and for sales-type leases at the inception of the lease term.

Revenue from equipment and software maintenance and post-contract support is recognized on a straight-line basis as earned over the terms of the respective contracts. Cost related to such contracts is recognized as incurred.

Revenue and profit under systems integration contracts are recognized over time as the company transfers control of goods or services. The company measures its progress toward satisfaction of its performance obligations using the cost-to-cost method, or when services have been performed, depending on the nature of the project. For contracts accounted for using the cost-to-cost method, revenue and profit recognized in any given accounting period are based on estimates of total projected contract costs. The estimates are continually reevaluated and revised, when necessary, throughout the life of a contract. Any adjustments to revenue and profit resulting from changes in estimates are accounted for in the period of the change in estimate. When estimates indicate that a loss will be incurred on a contract upon completion, a provision for the expected loss is recorded in the period in which the loss becomes evident.

Revenue from time and materials service contracts and outsourcing contracts is recognized as the services are provided using either an objective measure of output or on a straight-line basis over the term of the contract.

The company also enters into multiple-element arrangements, which may include any combination of hardware, software or services. For example, a client may purchase an enterprise server that includes operating system software. In addition, the arrangement may include post-contract support for the software and a contract for post-warranty maintenance for service of the hardware. These arrangements consist of multiple performance obligations, with control over hardware and software transferred in one reporting period and the software support and hardware maintenance services performed across multiple reporting periods. In another example, the company may provide desktop managed services to a client on a long-term multiple-year basis and periodically sell hardware and license software products to the client. The services are provided on a continuous basis across multiple reporting periods and control over the hardware and software products occurs in one reporting period. To the extent that a performance obligation in a multiple-deliverable arrangement is subject to specific guidance, that performance obligation is accounted for in accordance with such specific guidance. An example of such an arrangement may include leased assets which are subject to specific leasing accounting guidance.

In multiple-element arrangements, the company allocates the total transaction price to be earned under the arrangement among the various performance obligations in proportion to their standalone selling prices (relative standalone selling price basis). The standalone selling price for a performance obligation is the price at which the company would sell a promised good or service separately to a customer.

A performance obligation is a promise in a contract to transfer a distinct good or service to the customer. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. Many of the company’s contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and, therefore, not distinct. For contracts with multiple performance obligations, the company allocates the contract’s transaction price to each performance obligation using its best estimate of the standalone selling price of each distinct good or service in the contract. The primary methods used to estimate standalone selling price are as follows: (1) the expected cost plus margin approach, under which the company forecasts its expected costs of satisfying a performance obligation and then adds an appropriate margin for that distinct good or service and (2) the percent discount off of list price approach.

In the Services segment, substantially all of the company’s performance obligations are satisfied over time as work progresses and therefore substantially all of the revenue in this segment is recognized over time. The company generally receives payment for these contracts over time as the performance obligations are satisfied.

In the Technology segment, substantially all of the company’s goods and services are transferred to customers at a single point in time. Revenue on these contracts is recognized when control over the product is transferred to the customer or a software license term begins. The company generally receives payment for these contracts upon signature or within 30 to 60 days.

At March 31, 2018, the company had approximately $1.5 billion of remaining performance obligations of which approximately 50% is estimated to be recognized as revenue by the end of 2019. The company does not disclose the value of unsatisfied performance obligations for (1) contracts with an original expected length of one year or less and (2) contracts for which the company recognizes revenue at the amount to which it has the right to invoice for services performed.

The company discloses disaggregation of its customer revenue by geographic areas and by classes of similar products and services, by segment (see Note 15).

The timing of revenue recognition, billings and cash collections results in billed accounts receivables, unbilled receivables, contract assets and deferred revenue (contract liabilities). The disclosure of contract assets is a new requirement due to the adoption of Topic 606. At December 31, 2017, contract assets were included in accounts receivables, net on the company’s Consolidated Balance Sheet. At March 31, 2018, $6.0 million of long-term contract assets were included in other long-term assets on the company’s Consolidated Balance Sheet.

Significant changes during the three months ended March 31, 2018 in the above contract asset and liability balances were as follows: revenue of $104.6 million was recognized that was included in deferred revenue at December 31, 2017.

The company’s incremental direct costs of obtaining a contract consist of sales commissions which are deferred and amortized ratably over the initial contract life. These costs are classified as current or noncurrent based on the timing of when the company expects to recognize the expense. The current and noncurrent portions of deferred commissions are included in prepaid expenses and other current assets and in other long-term assets, respectively, in the company’s Consolidated Balance Sheets. At March 31, 2018 and December 31, 2017, the company had $10.1 million and $11.0 million, respectively, of deferred commissions. For the three months ended March 31, 2018, $1.7 million of amortization expense related to deferred commissions was recorded in selling, general and administrative expense in the company’s Consolidated Statement of Income.

Costs to fulfill a contract, which are incurred upon initiation of certain services contracts and are related to initial customer setup, are included in outsourcing assets, net in the company’s Consolidated Balance Sheet. The amount of such cost at March 31, 2018 and December 31, 2017 was $77.1 million and $76.0 million, respectively. These costs are amortized over the initial contract life and reported in services cost of sales. During the three months ended March 31, 2018, $3.6 million was amortized. Recoverability of these costs are subject to various business risks. Quarterly, the company compares the carrying value of these assets with the undiscounted future cash flows expected to be generated by them to determine if there is impairment. If impaired, these assets are reduced to an estimated fair value on a discounted cash flow basis. The company prepares its cash flow estimates based on assumptions that it believes to be reasonable but are also inherently uncertain. Actual cash flows could differ from these estimates.