XML 28 R44.htm IDEA: XBRL DOCUMENT
v3.19.3

Note 9 - Stock-based Compensation (Details Textual) - USD ($) $ / shares in Units, $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Sep. 30, 2019 | Sep. 30, 2018
Share-based Payment Arrangement, Expense | $ 3.2 | $ 3.0 | $ 9.7 | $ 8.0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value |  |  | $ 47.84 |
Share-based Payment Arrangement, Option [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period |  |  | 10 years |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total | 4.2 |  | $ 4.2 |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition |  |  | 2 years 9 months 18 days |
Share-based Payment Arrangement, Option [Member] | Minimum [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period |  |  | 4 years |
Share-based Payment Arrangement, Option [Member] | Maximum [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period |  |  | 5 years |
ESPP [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date |  |  | 15.00% |
Employee Stock Purchase Plan, Offering Period |  |  | 6 months |
Share-based Compensation Arrangement by Share-based Payment Award, Purchase Price of Common Stock, Percent |  |  | 85.00% |
Restricted Stock [Member] |  |  |  |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total | 24.4 |  | $ 24.4 |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition |  |  | 2 years 9 months 18 days |
Restricted Stock [Member] | Minimum [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period |  |  | 4 years |
Restricted Stock [Member] | Maximum [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period |  |  | 5 years |
Performance Shares [Member] |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period |  |  | 3 years |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total | $ 2.7 |  | $ 2.7 |
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition |  |  | 1 year 10 months 24 days |
Percentage of Target Number Capable of Being Earned and Vesting, Lower Limit | 0.00% |  | 0.00% |
Percentage of Target Number Capable of Being Earned and Vesting, Upper Limit | 150.00% |  | 150.00% |

X
- Definition The offering period during which employees may purchase stock through the Employee Stock Purchase Plan. + References No definition available. + Details
Name: | prlb_EmployeeStockPurchasePlanOfferingPeriod
Namespace Prefix: | prlb_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The lower limit percent of target number capable of being earned and vesting at the end of a three-year performance period depending on the company's performance in the final year of the performance period and the award recipient's continued employment. + References No definition available. + Details
Name: | prlb_PercentageOfTargetNumberCapableOfBeingEarnedAndVestingLowerLimit
Namespace Prefix: | prlb_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The upper limit percent of target number capable of being earned and vesting at the end of a three-year performance period depending on the company's performance in the final year of the performance period and the award recipient's continued employment. + References No definition available. + Details
Name: | prlb_PercentageOfTargetNumberCapableOfBeingEarnedAndVestingUpperLimit
Namespace Prefix: | prlb_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cost not yet recognized for nonvested award under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discount rate from fair value on offering date that participants pay for shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Purchase price of common stock expressed as a percentage of its fair value. + References No definition available. + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=prlb_ESPPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |