XML 53 R33.htm IDEA: XBRL DOCUMENT
v3.20.4

STOCK PLANS AND SHARE BASED COMPENSATION (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Summary of stock-based compensation expense [Table Text Block] | The following table summarizes the stock-based compensation expense recognized in accordance with ASC 718-10 for the years ended December 31, 2020, 2019 and 2018:
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Year Ended December 31,
(In thousands) |  | 2020 |  | 2019 |  | 2018
Cost of revenues | ​ | $ | 1,963 | ​ | $ | 1,237 | ​ | $ | 1,097
Research and development | ​ |  | 10,378 | ​ |  | 8,423 | ​ |  | 7,688
Sales and marketing | ​ |  | 6,290 | ​ |  | 5,015 | ​ |  | 4,729
General and administrative | ​ |  | 12,281 | ​ |  | 8,672 | ​ |  | 8,066
Total stock-based compensation expense | ​ | $ | 30,912 | ​ | $ | 23,347 | ​ | $ | 21,580
Share-based Payment Arrangement, Nonvested Award, Cost [Table Text Block] | The following table summarizes total compensation expense related to unvested awards not yet recognized, net of expected forfeitures, and the weighted average period over which it is expected to be recognized as of December 31, 2020:
​ | ​ | ​ | ​ | ​ | ​
​ |  | Unrecognized Compensation |  | Weighted Average
​ | ​ | Expense for Unvested | ​ | Remaining Recognition
​ | ​ | Awards | ​ | Period
​ | ​ | (In thousands) | ​ | (In years)
Long-term performance-based awards | ​ | $ | 5,810 |  | 1.64
Restricted stock units | ​ |  | 34,654 |  | 2.62
Purchase plan | ​ |  | 202 |  | 0.08
Total unrecognized compensation expense | ​ | $ | 40,666 |  |
Fair value assumptions for employees' stock purchase rights under the Purchase Plan [Table Text Block] | The fair value of employees’ stock purchase rights under the Purchase Plan was estimated using the Black-Scholes model with the following weighted-average assumptions used during the three years ended December 31, 2020, 2019 and 2018:
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Year Ended December 31, |
​ |  | 2020 | ​ | 2019 | ​ | 2018
Risk-free interest rates |  | ​ | 0.90 | % | ​ | ​ | 2.28 | % | ​ | ​ | 1.94 | %
Expected volatility rates |  | ​ | 47 | % | ​ | ​ | 37 | % | ​ | ​ | 31 | %
Expected dividend yield |  | ​ | 0.78 | % | ​ | ​ | 0.91 | % | ​ | ​ | 0.89 | %
Expected term of purchase rights (in years) |  | ​ | 0.50 |  | ​ | ​ | 0.50 |  | ​ | ​ | 0.50 |
Weighted-average estimated fair value of purchase rights | ​ | $ | 15.73 | ​ | ​ | $ | 19.39 | ​ | ​ | $ | 17.33 | ​
Summary of option activity under the Plans [Table Text Block] | A summary of stock options outstanding as of December 31, 2020, and activity during three years then ended, is presented below:
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Weighted- | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Average | ​ | ​ | ​
​ | ​ | ​ | ​ | Weighted- | ​ | Remaining | ​ | ​ | ​
​ | ​ | ​ | ​ | Average | ​ | Contractual | ​ | Aggregate
​ | ​ | Shares | ​ | Exercise | ​ | Term | ​ | Intrinsic Value
​ |  | (In thousands) |  | Price |  | (In years) |  | (In thousands)
Outstanding at January 1, 2018 |  | 1,022 | ​ | $ | 14.52 |  |  |  | ​ |
Granted |  | — | ​ |  | — |  |  |  | ​ |
Exercised |  | (352) | ​ | $ | 11.30 |  |  |  | ​ |
Forfeited or expired |  | — | ​ |  | — |  |  |  | ​ |
Outstanding at December 31, 2018 |  | 670 | ​ | $ | 16.21 |  |  |  | ​ |
Granted |  | — | ​ |  | — |  |  |  | ​ |
Exercised |  | (335) | ​ | $ | 12.98 |  |  |  | ​ |
Forfeited or expired |  | — | ​ |  | — |  |  |  | ​ |
Outstanding at December 31, 2019 |  | 335 | ​ | $ | 19.44 |  |  |  | ​ |
Granted |  | — | ​ |  | — |  |  |  | ​ |
Exercised |  | (243) | ​ | $ | 18.99 |  |  |  | ​ |
Forfeited or expired |  | — | ​ |  | — |  |  |  | ​ |
Outstanding at December 31, 2020 |  | 92 | ​ | $ | 20.63 |  | 1.05 | ​ | $ | 5,643
Vested and Exercisable at December 31, 2020 |  | 92 | ​ |  | ​ | ​ | 1.05 | ​ | $ | 5,643
Summary of stock options outstanding by exercise price range [Table Text Block] | The following table summarizes the stock options outstanding at December 31, 2020:
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Options Outstanding | ​ | Options Exercisable
​ |  | ​ |  | Weighted Average |  | Weighted |  | ​ |  | Weighted
​ | ​ | ​ | ​ | Remaining | ​ | Average | ​ | ​ | ​ | Average
(shares in thousands) | ​ | Options | ​ | Contractual Term | ​ | Exercise | ​ | Options | ​ | Exercise
Range of Exercise Prices | ​ | Outstanding | ​ | (in years) | ​ | Price | ​ | Exercisable | ​ | Price
$18.48 - $19.75 | ​ | 28 | ​ | 0.38 | ​ | $ | 18.77 | ​ | 28 | ​ | $ | 18.77
$21.44 - $21.44 |  | 64 |  | 1.35 | ​ | $ | 21.44 |  | 64 | ​ | $ | 21.44
​ |  | 92 |  | 1.05 | ​ | $ | 20.63 |  | 92 | ​ | $ | 20.63
Summary of restricted stock units outstanding [Table Text Block] | A summary of RSU awards outstanding as of December 31, 2020, and activity during the three years then ended, is presented below:
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Weighted-Average | ​ | Aggregate
​ | ​ | ​ | ​ | Weighted-Average | ​ | Remaining | ​ | Intrinsic
​ | ​ | Shares | ​ | Grant Date Fair | ​ | Contractual Term | ​ | Value
​ |  | (In thousands) |  | Value Per Share |  | (In years) |  | (In thousands)
Outstanding at January 1, 2018 |  | 1,896 | ​ | $ | 27.76 |  |  |  | ​ |
Granted |  | 550 | ​ | $ | 31.43 |  |  |  | ​ |
Vested |  | (592) | ​ | $ | 26.89 |  |  |  | ​ |
Forfeited |  | (64) | ​ | $ | 29.72 |  |  |  | ​ |
Outstanding at December 31, 2018 |  | 1,790 | ​ | $ | 29.10 |  |  |  | ​ |
Granted |  | 582 | ​ | $ | 34.90 |  |  |  | ​ |
Vested |  | (603) | ​ | $ | 28.10 |  |  |  | ​ |
Forfeited |  | (50) | ​ | $ | 31.72 |  |  |  | ​ |
Outstanding at December 31, 2019 |  | 1,719 | ​ | $ | 31.33 |  |  |  | ​ |
Granted |  | 439 | ​ | $ | 44.82 |  |  |  | ​ |
Vested |  | (599) | ​ | $ | 30.25 |  |  |  | ​ |
Forfeited |  | (41) | ​ | $ | 36.77 |  |  |  | ​ |
Outstanding at December 31, 2020 |  | 1,518 | ​ | $ | 35.51 |  | 1.42 | ​ | $ | 124,239
Outstanding and expected to vest at December 31, 2020 |  | 1,423 | ​ |  | ​ | ​ | 1.36 | ​ | $ | 116,475
Performance Based Awards [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Summary of performance-based awards outstanding [Table Text Block] | A summary of PSU awards outstanding as of December 31, 2020, and activity during the three years then ended, is presented below: ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Weighted- | ​ | ​ | ​
​ | ​ | ​ | ​ | Weighted- | ​ | Average | ​ | ​ | ​
​ | ​ | ​ | ​ | Average | ​ | Remaining | ​ | Aggregate
​ | ​ | Shares | ​ | Grant Date Fair | ​ | Contractual Term | ​ | Intrinsic Value
​ |  | (In thousands) |  | Value Per Share |  | (In years) |  | (In thousands)
Outstanding at January 1, 2018 |  | 158 | ​ | $ | 32.00 |  |  |  | ​ |
Granted |  | 178 | ​ | $ | 31.44 |  |  |  | ​ |
Vested |  | (158) | ​ | $ | 32.00 |  |  |  | ​ |
Forfeited or canceled |  | (126) | ​ | $ | 31.44 |  |  |  | ​ |
Outstanding at December 31, 2018 |  | 52 | ​ | $ | 31.44 |  |  |  | ​ |
Granted |  | 185 | ​ | $ | 35.06 |  |  |  | ​ |
Vested |  | (52) | ​ | $ | 31.44 |  |  |  | ​ |
Forfeited or canceled |  | (64) | ​ | $ | 35.06 |  |  |  | ​ |
Outstanding at December 31, 2019 |  | 121 | ​ | $ | 35.06 |  |  |  | ​ |
Granted |  | 150 | ​ | $ | 46.31 |  |  |  | ​ |
Vested |  | (121) | ​ | $ | 35.06 |  |  |  | ​ |
Forfeited or canceled |  | — | ​ | ​ | — |  |  |  | ​ |
Outstanding at December 31, 2020 |  | 150 | ​ | $ | 46.27 |  | — | ​ | $ | 12,219
Outstanding and expected to vest at December 31, 2020 |  | 150 | ​ |  | ​ | ​ | — | ​ | $ | 12,219
Long-Term Performance-based Awards [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Summary of performance-based awards outstanding [Table Text Block] | A summary of PRSU awards outstanding as of December 31, 2020, and activity during the three years then ended, is presented below:
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | Weighted-Average | ​ | Aggregate
​ | ​ | ​ | ​ | Weighted-Average | ​ | Remaining | ​ | Intrinsic
​ | ​ | Shares | ​ | Grant Date Fair | ​ | Contractual Term | ​ | Value
​ |  | (In thousands) |  | Value Per Share |  | (In years) |  | (In thousands)
Outstanding at January 1, 2018 |  | 368 | ​ | $ | 26.40 |  |  |  | ​ |
Granted |  | 144 | ​ | $ | 29.95 |  |  |  | ​ |
Vested |  | (76) | ​ | $ | 26.23 |  |  |  | ​ |
Forfeited or canceled |  | (10) | ​ | $ | 21.63 |  |  |  | ​ |
Outstanding at December 31, 2018 |  | 426 | ​ | $ | 27.74 |  |  |  | ​ |
Granted |  | 144 | ​ | $ | 34.09 |  |  |  | ​ |
Vested |  | (140) | ​ | $ | 21.63 |  |  |  | ​ |
Forfeited or canceled |  | (143) | ​ | $ | 31.50 |  |  |  | ​ |
Outstanding at December 31, 2019 |  | 287 | ​ | $ | 32.03 |  |  |  | ​ |
Granted |  | 152 | ​ | $ | 49.67 |  |  |  | ​ |
Vested |  | — | ​ | ​ | — |  |  |  | ​ |
Forfeited or canceled |  | (138) | ​ | $ | 29.95 |  |  |  | ​ |
Outstanding at December 31, 2020 |  | 301 | ​ | $ | 41.90 |  | 1.51 | ​ | $ | 24,637
Outstanding and expected to vest at December 31, 2020 |  | 272 | ​ |  | ​ | ​ | 1.54 | ​ | $ | 22,279

X
- Definition Tabular disclosure of allocation of amount expensed and capitalized for award under share-based payment arrangement to statement of income or comprehensive income and statement of financial position. Includes, but is not limited to, corresponding line item in financial statement. + 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 (h)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 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 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901 + Details
Name: | us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the changes in outstanding nonvested performance-based units. + 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 (c)(2) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the number and weighted-average grant date fair value for restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock units that were granted, vested, or forfeited during the year. + 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 (c)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of option exercise prices, by grouped ranges, including the upper and lower limits of the price range, the number of shares under option, weighted average exercise price and remaining contractual option terms. + 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_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value. + 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) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 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 (c)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the significant assumptions used during the year to estimate the fair value of employee stock purchase plans, including, but not limited to: (a) expected term, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions. + 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 (f)(2) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of cost not yet recognized and weighted-average period over which cost is expected to be 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_ScheduleOfUnrecognizedCompensationCostNonvestedAwardsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

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