XML 41 R25.htm IDEA: XBRL DOCUMENT
v3.8.0.1

MARKETABLE SECURITIES (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2017
Cash and Cash Equivalents [Abstract] |
Summary of Available-for-Sale Marketable Securities | The following is a summary of available-for-sale marketable securities at December 31, 2016 and 2017:
|  | As at December 31, 2017 |
|  | Amortized cost |  |  | Gross unrealized gains |  |  | Gross unrealized losses |  |  | Fair value |
Available-for-sale—matures within one year: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Corporate bonds |  | $ | 11,803 |  |  | $ | 3 |  |  | $ | (12 | ) |  | $ | 11,794 |
|  |  | 11,803 |  |  |  | 3 |  |  |  | (12 | ) |  |  | 11,794 |
Available-for-sale—matures after one year through five years: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Certificate of deposits |  |  | 747 |  |  |  | — |  |  |  | — |  |  |  | 747 |
Government bonds |  |  | 501 |  |  |  | — |  |  |  | (6 | ) |  |  | 495 |
Corporate bonds |  |  | 70,291 |  |  |  | 14 |  |  |  | (677 | ) |  |  | 69,628 |
|  |  | 71,539 |  |  |  | 14 |  |  |  | (683 | ) |  |  | 70,870 |
Total |  | $ | 83,342 |  |  | $ | 17 |  |  | $ | (695 | ) |  | $ | 82,664 |
|  | As at December 31, 2016 |
|  | Amortized cost |  |  | Gross unrealized gains |  |  | Gross unrealized losses |  |  | Fair value |
Available-for-sale—matures within one year: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Corporate bonds |  | $ | 9,456 |  |  | $ | 4 |  |  | $ | (15 | ) |  | $ | 9,445 |
|  |  | 9,456 |  |  |  | 4 |  |  |  | (15 | ) |  |  | 9,445 |
Available-for-sale—matures after one year through five years: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Government bonds |  |  | 501 |  |  |  | — |  |  |  | (4 | ) |  |  | 497 |
Corporate bonds |  |  | 52,490 |  |  |  | 3 |  |  |  | (567 | ) |  |  | 51,926 |
|  |  | 52,991 |  |  |  | 3 |  |  |  | (571 | ) |  |  | 52,423 |
Total |  | $ | 62,447 |  |  | $ | 7 |  |  | $ | (586 | ) |  | $ | 61,868 |
Summary of Gross Unrealized Losses and Fair Values on Investments | The following table presents gross unrealized losses and fair values for those investments that were in an unrealized loss position as of December 31, 2016 and 2017, and the length of time that those investments have been in a continuous loss position:
|  | Less than 12 months |  |  | 12 months or greater |
|  | Fair Value |  |  | Gross unrealized loss |  |  | Fair Value |  |  | Gross unrealized loss |
As of December 31, 2017 |  | $ | 49,921 |  |  | $ | (411 | ) |  | $ | 22,960 |  |  | $ | (284 | )
As of December 31, 2016 |  | $ | 48,663 |  |  | $ | (557 | ) |  | $ | 4,875 |  |  | $ | (29 | )
Summary of Gross Realized Gains and Losses from Sale of Available-for-Sale Marketable Securities | The following table presents gross realized gains and losses from sale of available-for-sale marketable securities:
|  | Year ended December 31, |
|  | 2015 |  |  | 2016 |  |  | 2017 |
Gross realized gains from sale of available-for-sale marketable securities |  | $ | 4 |  |  | $ | 24 |  |  | $ | 47 |
Gross realized losses from sale of available-for-sale marketable securities |  | $ | (82 | ) |  | $ | (33 | ) |  | $ | (47 | )

X
- Definition Tabular disclosure of fair value of investments in debt and equity securities in an unrealized loss position categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_CashAndCashEquivalentsAbstract
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

X
- Definition Tabular disclosure of the proceeds from sales of available-for-sale securities and the gross realized gains and gross realized losses that have been included in earnings as a result of those sales. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563 + Details
Name: | us-gaap_ScheduleOfRealizedGainLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration