Balance Sheet Account Details
|12 Months Ended|
Dec. 31, 2018
|Other Balance Sheet Details [Abstract]|
|Balance Sheet Account Details||Balance Sheet Account DetailsShort-term Investments
The following table summarizes the various investment categories at December 31, 2018 and 2017 (in thousands):
Other current assets consist of the following (in thousands):
Property and equipment is stated at cost and consists of the following (in thousands):
Depreciation of equipment is computed using the straight-line method over the estimated useful lives of the assets which range from three to ten years. Leasehold improvements are amortized using the straight-line method over their estimated useful lives or their related lease term, whichever is shorter. Depreciation expense of $0.9 million, $0.4 million, and $0.2 million was recognized for the years ended December 31, 2018, 2017, and 2016, respectively, and is included in operating expenses.
Goodwill and identifiable intangible assets consist of the following (in thousands):
Amortization of finite lived intangible assets is computed using the straight-line method over the estimated useful life of the asset of 20 years. Amortization expense of $15.8 million, $11.3 million, and $10.6 million was recognized for the years ended December 31, 2018 and 2017, and 2016, respectively. Estimated amortization expense for the years ending December 31, 2018 through 2023 is $13.6 million per year. For each of the years ended December 31, 2018, 2017, and 2016, there was no impairment of intangible assets with finite lives.
Accrued liabilities consist of the following (in thousands):
In connection with the acquisition of CyDex in January 2011, we issued a series of CVRs and also assumed certain contingent liabilities. We may be required to make additional payments upon achievement of certain clinical and regulatory milestones to the CyDex shareholders and former license holders. We paid CyDex shareholders, through 2016, 20% of all CyDex-related revenue, but only to the extent that, and beginning only when, CyDex-related revenue for the year exceeds $15.0 million; plus an additional 10% of all CyDex-related revenue recognized during such year, but only to the extent, and beginning only when aggregate CyDex-related revenue for such year exceeds $35.0 million.
In connection with the acquisition of Metabasis in January 2010, we entered into four CVR agreements with Metabasis shareholders. The CVRs entitle the holders to cash payments as frequently as every six months as proceeds are received by us upon the sale or licensing of any of the Metabasis drug development programs and upon the achievement of specified milestones.
The following table summarizes contingent liabilities as of December 2018 and 2017 (in thousands):
The entire disclosure for supplemental balance sheet disclosures, including descriptions and amounts for assets, liabilities, and equity.
Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef