Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 09, 2021	Jun. 28, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	1-38643
Entity Registrant Name	PAE INCORPORATED
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-3173473
Entity Address, Address Line One	7799 Leesburg Pike
Entity Address, Address Line Two	Suite 300 North
Entity Address, City or Town	Falls Church
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	22043
City Area Code	703
Local Phone Number	717-6000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 641,171,952
Entity Common Stock, Shares Outstanding		93,069,815
Documents Incorporated by Reference	Portions of the definitive proxy statement relating to the registrant’s annual meeting of stockholders are incorporated by reference in response to Items 10, 11, 12, 13 and 14 of Part III of this Form 10-K.
Entity Central Index Key	0001720821
Amendment Flag	false
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2020
Class A Common Stock
Entity Information [Line Items]
Title of 12(b) Security	Class A Common Stock
Trading Symbol	PAE
Security Exchange Name	NASDAQ
Warrants
Entity Information [Line Items]
Title of 12(b) Security	Warrants
Trading Symbol	PAEWW
Security Exchange Name	NASDAQ