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Balance Sheet Components - Summary of Cash Equivalents and Available-for-sale Securities (Detail) - USD ($) $ in Thousands | Dec. 31, 2016 | Dec. 31, 2015
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Cash Equivalents and Available-for-Sale Securities [Line Items] |  |
Total cash equivalents and available-for-sale securities, Amortized Cost | $ 85,241 | $ 10,009
Total cash equivalents and available-for-sale securities, Gross Unrealized Gains | 2 |
Total cash equivalents and available-for-sale securities, Gross Unrealized Losses | (74) | (5)
Total cash equivalents and available-for-sale securities, Fair Value | 85,169 | 10,004
Cash equivalents | 18,504 | 2,136
Available-for-sale securities - current | 56,515 | 7,868
Available-for-sale securities - noncurrent | 10,150 |
Corporate Bonds Member] |  |
Cash Equivalents and Available-for-Sale Securities [Line Items] |  |
Total cash equivalents and available-for-sale securities, Amortized Cost | 21,886 | 7,373
Total cash equivalents and available-for-sale securities, Gross Unrealized Losses | (45) | (5)
Total cash equivalents and available-for-sale securities, Fair Value | 21,841 | 7,368
Governmental Bonds [Member] |  |
Cash Equivalents and Available-for-Sale Securities [Line Items] |  |
Total cash equivalents and available-for-sale securities, Amortized Cost | 41,316 |
Total cash equivalents and available-for-sale securities, Gross Unrealized Gains | 2 |
Total cash equivalents and available-for-sale securities, Gross Unrealized Losses | (29) |
Total cash equivalents and available-for-sale securities, Fair Value | 41,289 |
Money Market Funds [Member] |  |
Cash Equivalents and Available-for-Sale Securities [Line Items] |  |
Total cash equivalents and available-for-sale securities, Amortized Cost | 11,270 | 2,136
Total cash equivalents and available-for-sale securities, Fair Value | 11,270 | 2,136
Commercial Paper [Member] |  |
Cash Equivalents and Available-for-Sale Securities [Line Items] |  |
Total cash equivalents and available-for-sale securities, Amortized Cost | 10,769 | 500
Total cash equivalents and available-for-sale securities, Fair Value | $ 10,769 | $ 500

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- Definition Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26626-111562 + Details
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- Definition Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Available-for-Sale Securities -URI http://asc.fasb.org/extlink&oid=6505594 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26626-111562 + Details
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