Deferred tax operating loss carryforwards expiration description.

No definition available.

Name:	psn_DeferredTaxOperatingLossCarryforwardsExpirationDescription
Namespace Prefix:	psn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Deferred tax operating loss carryforwards expiration year.

+ References

No definition available.

+ Details

Name:	psn_DeferredTaxOperatingLossCarryforwardsExpirationYear
Namespace Prefix:	psn_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

Income taxes.

+ References

No definition available.

+ Details

Name:	psn_IncomeTaxesLineItems
Namespace Prefix:	psn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Increase (decrease) in current income tax expense due to one big beautiful bill act.

+ References

No definition available.

+ Details

Name:	psn_IncreaseDecreaseInCurrentIncomeTaxExpenseDueToOneBigBeautifulBillAct
Namespace Prefix:	psn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Increase (decrease) in deferred tax assets due to one big beautiful bill act.

+ References

No definition available.

+ Details

Name:	psn_IncreaseDecreaseInDeferredTaxAssetsDueToOneBigBeautifulBillAct
Namespace Prefix:	psn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Increase (decrease) in deferred tax expense due to one big beautiful bill act.

+ References

No definition available.

+ Details

Name:	psn_IncreaseDecreaseInDeferredTaxExpenseDueToOneBigBeautifulBillAct
Namespace Prefix:	psn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Increase (decrease) in income tax payable due to one big beautiful bill act.

+ References

No definition available.

+ Details

Name:	psn_IncreaseDecreaseInIncomeTaxPayableDueToOneBigBeautifulBillAct
Namespace Prefix:	psn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Tax credit carry forward expiration year.

+ References

No definition available.

+ Details

Name:	psn_TaxCreditCarryForwardExpirationYear
Namespace Prefix:	psn_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-6

+ Details

Name:	us-gaap_DeferredTaxAssetsOperatingLossCarryforwards
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards that are not subject to expiration dates.

+ References

+ Details

Name:	us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

Name:	us-gaap_DeferredTaxAssetsValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

+ Details

Name:	us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after refund, of cash paid to foreign, federal, state, and local jurisdictions as income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-2A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 23
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-23

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-22

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-2

+ Details

Name:	us-gaap_IncomeTaxesPaidNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Tax year that remains open to examination under enacted tax laws, in YYYY format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15

+ Details

Name:	us-gaap_OpenTaxYear
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:gYearListItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-3

+ Details

Name:	us-gaap_TaxCreditCarryforwardAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from tax credit carryforwards for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

Name:	us-gaap_TaxCreditCarryforwardValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 217
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-217

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15

+ Details

Name:	us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of expense for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

+ References

+ Details

Name:	us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 217
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-217

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15A

+ Details

Name:	us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

Name:	us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=us-gaap_ForeignCountryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=psn_StateAndLocalJurisdictionAndForeignMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=us-gaap_DomesticCountryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income Taxes [Line Items]
Decrease in income tax payable due to One Big Beautiful Bill Act	$ (29,000)
Decrease in current income tax expense due to One Big Beautiful Bill Act	(29,000)
Increase in deferred tax expense due to One Big Beautiful Bill Act	29,000
Decrease in deferred tax assets due to One Big Beautiful Bill Act	$ (29,000)
Effective income tax rate	19.30%	20.90%	21.30%
Deferred tax assets, valuation allowance	$ 50,558	$ 45,318
Deferred tax assets, increase in valuation allowance	5,300
Net operating loss carryforwards	15,107	17,640
Unrecognized tax benefits that would impact effective tax rate	26,500	28,600
Unrecognized tax benefits, income tax penalties and interest expense	700	1,000	$ 500
Unrecognized tax benefits, income tax penalties and interest accrued	6,300	5,600	4,600
Cash income taxes paid (net of refunds received)	30,794	$ 59,800	$ 74,100
U.S. States
Income Taxes [Line Items]
Net operating loss carryforwards	43,700
Net operating loss carryforwards, not subject to expiration	17,900
Foreign
Income Taxes [Line Items]
Net operating loss carryforwards	59,600
Net operating loss carryforwards, not subject to expiration	25,100
Foreign tax credit carryforwards	39,000
Foreign tax credits, valuation allowance	$ 39,000
Foreign tax credits, expiration year	2029
U.S. States and Foreign
Income Taxes [Line Items]
Net operating loss carryforwards, expiration description	expire if not used between 2026 and 2046
U.S. States and Foreign \| Minimum
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year	2026
U.S. States and Foreign \| Maximum
Income Taxes [Line Items]
Net operating loss carryforwards, expiration year	2046
U.S. Federal
Income Taxes [Line Items]
Net operating loss carryforwards	$ 2,000
Net operating loss carryforwards, not subject to expiration	$ 2,000
Open tax year	2022 2023 2024 2025