Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 17, 2022	Jun. 30, 2021
Document Information Line Items
Entity Registrant Name	FTAC PARNASSUS ACQUISITION CORP.
Trading Symbol	FTPA
Document Type	10-K
Current Fiscal Year End Date	--12-31
Entity Public Float			$ 244,000,000
Amendment Flag	false
Entity Central Index Key	0001839972
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Shell Company	true
Entity Ex Transition Period	false
ICFR Auditor Attestation Flag	false
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-40203
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	85-4366403
Entity Address, Address Line One	2929 Arch Street,
Entity Address, Address Line Two	Suite 1703,
Entity Address, City or Town	Philadelphia
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19104
City Area Code	(215)
Local Phone Number	701-9555
Title of 12(b) Security	Class A common stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Entity Interactive Data Current	Yes
Auditor Name	WithumSmith+Brown, PC
Auditor Location	New York, New York
Auditor Firm ID	100
Class A Common Stock
Document Information Line Items
Entity Common Stock, Shares Outstanding		25,690,000
Class B Common Stock
Document Information Line Items
Entity Common Stock, Shares Outstanding		8,563,333