XML 46 R32.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Investments (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2018
Investments |
Schedule of amortized cost and fair value of available-for-sale securities |
|  |  |  |  | Gross |  | Gross |  |
|  | Amortized |  | Unrealized |  | Unrealized |  | Estimated
|  | Cost |  | Gains |  | Losses |  | Fair Value
|  | (in thousands)
December 31, 2018 |  |  |  |  |  |  |  |  |  |  |  |
U.S. treasuries |  | $ | 37,191 |  | $ | — |  | $ | (7) |  | $ | 37,184
Corporate debt |  |  | 8,525 |  |  | — |  |  | (9) |  |  | 8,516
Commercial paper |  |  | 2,489 |  |  | — |  |  | — |  |  | 2,489
Total |  | $ | 48,205 |  | $ | — |  | $ | (16) |  | $ | 48,189
December 31, 2017 |  |  |  |  |  |  |  |  |  |  |  |
U.S. treasuries |  | $ | 33,914 |  | $ | — |  | $ | (19) |  | $ | 33,895
Corporate debt |  |  | 10,894 |  |  | — |  |  | (8) |  |  | 10,886
Commercial paper |  |  | 2,999 |  |  | — |  |  | — |  |  | 2,999
Total |  | $ | 47,807 |  | $ | — |  | $ | (27) |  | $ | 47,780
Schedule of fair value and unrealized losses of available-for-sale securities in a loss position |
|  | December 31, 2018 |  | December 31, 2017
|  |  |  |  | Gross |  |  |  | Gross
|  | Estimated |  | Unrealized |  | Estimated |  | Unrealized
|  | Fair Value |  | Losses |  | Fair Value |  | Losses
|  | (in thousands)
U.S. treasuries |  | $ | 37,184 |  | $ | (7) |  | $ | 33,895 |  | $ | (19)
Corporate debt |  |  | 8,516 |  |  | (9) |  |  | 10,886 |  |  | (8)
Total |  | $ | 45,700 |  | $ | (16) |  | $ | 44,781 |  | $ | (27)

X
- Definition Tabular disclosure of fair value amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration