XML 42 R32.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Balance Sheet Components - Summary of Cash Equivalents and Available-for-sale Securities (Detail) - USD ($) $ in Thousands | Sep. 30, 2016 | Dec. 31, 2015
--- | --- | ---
Cash and Cash Equivalents [Line Items] |  |
Total cash equivalents and available-for-sale securities, Amortized Cost | $ 97,621 | $ 10,009
Total cash equivalents and available-for-sale securities, Gross Unrealized Gains | 0 | 0
Total cash equivalents and available-for-sale securities, Gross Unrealized Losses |  | (5)
Total cash equivalents and available-for-sale securities, Fair Value | 97,621 | 10,004
Cash equivalents | 95,122 | 2,136
Available-for-sale securities | 2,499 | 7,868
Corporate Bonds Member] |  |
Cash and Cash Equivalents [Line Items] |  |
Total cash equivalents and available-for-sale securities, Amortized Cost | 600 | 7,373
Total cash equivalents and available-for-sale securities, Gross Unrealized Gains | 0 | 0
Total cash equivalents and available-for-sale securities, Gross Unrealized Losses |  | (5)
Total cash equivalents and available-for-sale securities, Fair Value | 600 | 7,368
Money Market Funds [Member] |  |
Cash and Cash Equivalents [Line Items] |  |
Total cash equivalents and available-for-sale securities, Amortized Cost | 95,122 | 2,136
Total cash equivalents and available-for-sale securities, Gross Unrealized Gains | 0 | 0
Total cash equivalents and available-for-sale securities, Fair Value | 95,122 | 2,136
Commercial Paper [Member] |  |
Cash and Cash Equivalents [Line Items] |  |
Total cash equivalents and available-for-sale securities, Amortized Cost | 1,899 | 500
Total cash equivalents and available-for-sale securities, Gross Unrealized Gains | 0 | 0
Total cash equivalents and available-for-sale securities, Fair Value | $ 1,899 | $ 500

X
- Definition Cash equivalents and available for sale securities amortized cost. + References No definition available. + Details
Name: | ptgx_CashEquivalentsAndAvailableForSaleSecuritiesAmortizedCost
Namespace Prefix: | ptgx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Cash equivalents and available for sale securities fair value. + References No definition available. + Details
Name: | ptgx_CashEquivalentsAndAvailableForSaleSecuritiesFairValue
Namespace Prefix: | ptgx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Cash equivalents and available for sale securities gross unrealized gain. + References No definition available. + Details
Name: | ptgx_CashEquivalentsAndAvailableForSaleSecuritiesGrossUnrealizedGain
Namespace Prefix: | ptgx_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Cash equivalents and available for sale securities gross unrealized loss. + References No definition available. + Details
Name: | ptgx_CashEquivalentsAndAvailableForSaleSecuritiesGrossUnrealizedLoss
Namespace Prefix: | ptgx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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
Name: | us-gaap_AvailableForSaleSecuritiesCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_CashAndCashEquivalentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 + Details
Name: | us-gaap_CashEquivalentsAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CashAndCashEquivalentsAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CashAndCashEquivalentsAxis=us-gaap_CommercialPaperMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |