v3.25.4
Document and Entity Information - USD ($)
$ in Billions
12 Months Ended
Dec. 31, 2025
Feb. 03, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2025    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
Entity Registrant Name PARSONS CORPORATION    
Entity Central Index Key 0000275880    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Current Fiscal Year End Date --12-31    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   105,831,019  
Entity Public Float     $ 7.7
Entity Shell Company false    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity File Number 001-07782    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 95-3232481    
Entity Address, Address Line One 14291 Park Meadow Drive    
Entity Address, Address Line Two Suite 100    
Entity Address, City or Town Chantilly    
Entity Address, State or Province VA    
Entity Address, Postal Zip Code 20151    
City Area Code 703    
Local Phone Number 988-8500    
Document Annual Report true    
Document Transition Report false    
ICFR Auditor Attestation Flag true    
Document Financial Statement Error Correction Flag false    
Title of each class Common Stock, $1 par value    
Trading Symbol(s) PSN    
Name of each exchange on which registered NYSE    
Auditor Name PricewaterhouseCoopers LLP    
Auditor Location Los Angeles, California    
Auditor Firm ID 238    
Auditor Opinion

Opinions on the Financial Statements and Internal Control over Financial Reporting

We have audited the accompanying consolidated balance sheets of Parsons Corporation and its subsidiaries (the "Company") as of December 31, 2025 and 2024, and the related consolidated statements of income, of comprehensive income, of changes in shareholders' equity and of cash flows for each of the three years in the period ended December 31, 2025, including the related notes and schedule of valuation and qualifying accounts for each of the three years in the period ended December 31, 2025 appearing under Item 15(a)(2) (collectively referred to as the "consolidated financial statements"). We also have audited the Company's internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025 in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control - Integrated Framework (2013) issued by the COSO.

   
Documents Incorporated by Reference

Portions of Parsons’ 2026 Proxy Statement are incorporated by reference into Part III of this Annual Report on Form 10-K.