Summary of business and significant accounting policies (Policies)

6 Months Ended

Jun. 30, 2017

Accounting Policies [Abstract]

Basis of presentation

Basis of presentation.The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP). The Company's fiscal year ends on December 31, and its fiscal quarters end on March 31, June 30 and September 30. The condensed consolidated financial statements reflect all adjustments (which are normal and recurring in nature) that management believes are necessary for the fair statement of the Company's financial statements, but are not necessarily indicative of the results expected for the full fiscal year or any other future period. The condensed consolidated balance sheet at December 31, 2016 has been derived from the audited financial statements at that date, but does not include all the disclosures required by GAAP. This Quarterly Report on Form 10-Q should be read in conjunction with the Company's Annual Report on Form 10-K (Annual Report) for the year ended December 31, 2016. There have been no significant changes in the Company’s accounting policies from those disclosed in its Annual Report.

Principles of consolidation

Principles of consolidation. These condensed consolidated financial statements include all the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Use of estimates

Use of estimates. The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the Company’s condensed consolidated financial statements and accompanying notes. Significant estimates and assumptions made by management include those related to revenue recognition (including sales returns, implied post contract support and marketing allowances), stock-based compensation, inventory valuation, product warranty liabilities, the valuation and useful lives of long-lived assets (property and equipment, intangible assets and goodwill) and income taxes. The Company bases its estimates and assumptions on historical experience and on various other factors that it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results could differ materially from management's estimates. To the extent there are material differences between the estimates and the actual results, future results of operations could be affected.

Comprehensive income (loss)

Comprehensive income (loss).For all periods presented, comprehensive income (loss) approximated net income (loss). Therefore, the condensed consolidated statements of comprehensive income (loss) have been omitted

Prior period reclassifications

Prior period reclassifications. Reclassifications of certain prior period amounts in the condensed consolidated financial statements have been made to conform to the current period presentation.

Recent accounting pronouncements

Recent accounting standards

Standard	Description	Date of adoption	Effect on the financial statements or other significant matters
Standards that were adopted
Stock Compensation  Accounting Standards Update (ASU) No. 2016-09 (Topic 718)	This standard simplifies certain aspects of the accounting for share-based payment transactions, including income taxes, classification of awards and classification on the statement of cash flows. The new guidance also allows an entity to make a policy election to account for forfeitures as they occur.	January 1, 2017	Adoption of the standard resulted in the recognition of previously unrecognized excess tax benefits using the modified retrospective method. The Company recorded an increase to U.S. deferred tax assets of $179 million which was recorded directly against accumulated deficit. The increased deferred tax asset allowed for an offset against long-term income tax payable of $16 million. A full valuation allowance was provided on the remaining U.S. deferred tax asset of $163 million, which was also recorded against accumulated deficit. The net impact to equity was a decrease in the accumulated deficit of approximately $16 million. The Company elected to apply the change in presentation to the statements of cash flows prospectively and elected to account for forfeitures as they occur.
Standards not yet adopted
Revenue from Contracts with Customers ASU No. 2014-09, 2016-08, 2016-10 and 2016-12 (Topic 606)	The updated revenue standard establishes principles for recognizing revenue and develops a common revenue standard for all industries. Under the new model, recognition of revenue occurs when a customer obtains control of promised goods or services in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The new standard requires that entities disclose the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. Early adoption is permitted, but not earlier than the first quarter of 2017. The retrospective or cumulative effect transition method is permitted.	January 1, 2018	The Company completed an initial analysis of the impact of the standard on its sales contract portfolio by reviewing its current accounting policies and practices to identify potential differences that would result from applying the requirements of the new standard to its sales contracts. The Company's analysis of its contracts under the new standard supports the recognition of most of its revenue at the time product is shipped, consistent with its current revenue policy. Although the Company is continuing to review certain aspects of its policies and practices, it expects that, as a result of the adoption of the new guidance, the timing of recognizing certain sales incentives as a reduction of revenue will generally be earlier than under the existing guidance. (The Company recognized approximately $19 and $42 million as a reduction to revenue for such sales incentives for the first six months of 2017 and for the full year 2016, respectively.) The Company does not expect that the adoption of ASU 2014-09 will have a material impact to the quarterly or yearly sales incentives recognized.  The Company expects to utilize the modified retrospective transition method.
Leases ASU No. 2016-02(Topic 842)	This standard requires lessees to put most leases on their balance sheets but recognize the expenses on their income statements in a manner similar to current practice. Lessees would recognize a right-to-use asset and lease liability for all leases with terms of more than 12 months. The new standard should be applied on a modified retrospective basis.	January 1, 2019	Although the Company is currently evaluating the impact that the adoption of this standard will have on its consolidated financial statements and related disclosures, the Company currently expects that most of its operating lease commitments will be subject to the new standard and recognized as operating lease liabilities and right-of-use assets upon adoption.
Income Taxes ASU No. 2016-16 (Topic 740)	This standard requires entities to recognize the income tax consequences of intra-entity asset transfers when they occur. This removes the exception to postpone recognition until the asset has been sold to an outside party. The updated standard is effective in annual and interim periods in fiscal years beginning after December 15, 2017, with early adoption permitted during the first interim period of a fiscal year.	January 1, 2018	The Company is evaluating the impact that the adoption of this standard will have on its consolidated financial statements and related disclosures.

Intangible - Goodwill and Other ASU No. 2017-04 (Topic 350)	This standard simplifies the accounting for goodwill and removes Step 2 of the annual goodwill impairment test. Upon adoption, goodwill impairment will be determined based on the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. Early adoption permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017, and requires a prospective transition method.	January 1, 2020	The Company does not expect the adoption of this standard will have a material impact on its consolidated financial statements and related disclosures.
Stock Compensation  ASU No. 2017-09 (Topic 718)	This standard clarifies when to account for a change to the terms or conditions of a share-based payment award as a modification. Under this standard, modification is required only if the fair value, the vesting conditions, or the classification of an award as equity or liability changes as a result of the change in terms or conditions. The updated standard is effective in annual and interim periods in fiscal years beginning after December 15, 2017, with early adoption permitted.	January 1, 2018	The Company is evaluating the impact that the adoption of this standard will have on its consolidated financial statements and related disclosures.