Subsequent Events	3 Months Ended
Mar. 31, 2023
Subsequent Events [Abstract]
Subsequent Events	19. Subsequent Events On April 13, 2023, the Company entered into a merger agreement to acquire a 100% ownership interest in IPKeys Power Partners (“IPKeys”), a privately-owned company, for $43.2 million from cash on hand. The merger brings IPKeys' established customer base, expanding Parsons' presence in two rapidly growing end markets: grid modernization and cyber resiliency for critical infrastructure. Headquartered in Tinton Falls, New Jersey, IPKeys is a trusted provider of enterprise software platform solutions that is actively delivering cyber and operational security to hundreds of electric, water, and gas utilities across North America. At the timing of the filing of this Form 10-Q, the Company has just started the process of obtaining the relevant data to make the required acquisition related disclosures.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI https://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

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