XML 39 R22.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Fair Value Measurements (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2017
Fair Value Disclosures [Abstract] |
Fair Value Measurements of Cash Equivalents and Available-For-Sale Investment Securities | The recurring fair value measurements of the Company’s cash equivalents and available-for-sale investment securities at December 31, 2017 and 2016 consisted of the following (in thousands):
|  |  |  |  |  | Fair Value Measurements at Reporting Date Using |
|  | December 31, 2017 |  |  | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  | Significant Other Observable Inputs (Level 2) |  |  | Significant Unobservable Inputs (Level 3) |
Money market fund |  | $ | 38,057 |  |  | $ | 38,057 |  |  | $ | — |  |  | $ | — |
U.S. Treasury notes |  |  | 32,964 |  |  |  | 32,964 |  |  |  | — |  |  |  | — |
Government sponsored enterprise securities |  |  | 10,072 |  |  |  | — |  |  |  | 10,072 |  |  |  | — |
Corporate debt securities |  |  | 154,396 |  |  |  | — |  |  |  | 154,396 |  |  |  | — |
Commercial paper |  |  | 98,052 |  |  |  | — |  |  |  | 98,052 |  |  |  | — |
|  | $ | 333,541 |  |  | $ | 71,021 |  |  | $ | 262,520 |  |  | $ | — |
|  |  |  |  |  | Fair Value Measurements at Reporting Date Using |
|  | December 31, 2016 |  |  | Quoted Prices in Active Markets for Identical Assets (Level 1) |  |  | Significant Other Observable Inputs (Level 2) |  |  | Significant Unobservable Inputs (Level 3) |
Money market fund |  | $ | 129,292 |  |  | $ | 129,292 |  |  | $ | — |  |  | $ | — |
U.S. Treasury notes |  |  | 82,487 |  |  |  | 82,487 |  |  |  | — |  |  |  | — |
Government sponsored enterprise securities |  |  | 88,773 |  |  |  | — |  |  |  | 88,773 |  |  |  | — |
Corporate debt securities |  |  | 82,857 |  |  |  | — |  |  |  | 82,857 |  |  |  | — |
Commercial paper |  |  | 140,024 |  |  |  | — |  |  |  | 140,024 |  |  |  | — |
|  | $ | 523,433 |  |  | $ | 211,779 |  |  | $ | 311,654 |  |  | $ | — |

X
- Definition Tabular disclosure of assets, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, by class that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19190-110258 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_FairValueDisclosuresAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration