Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2022	Feb. 16, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-14875
Entity Registrant Name	FTI CONSULTING, INC.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	52-1261113
Entity Address, Address Line One	555 12th Street NW
Entity Address, City or Town	Washington,
Entity Address, State or Province	DC
Entity Address, Postal Zip Code	20004
City Area Code	202
Local Phone Number	312-9100
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	FCN
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 5.3
Entity Common Stock, Shares Outstanding		33,925,312
Documents Incorporated by Reference	Portions of our definitive Proxy Statement to be filed with the U.S. Securities and Exchange Commission within 120 days after the end of our 2022 fiscal year are incorporated by reference into Part III of this Annual Report on Form 10-K to the extent stated herein.
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Entity Central Index Key	0000887936