Cover
Dec. 21, 2021
Cover [Abstract]  
Document Type 8-K
Document Period End Date Dec. 21, 2021
Entity Registrant Name PhaseBio Pharmaceuticals, Inc.
Entity Incorporation, State or Country Code DE
Entity File Number 001-38697
Entity Tax Identification Number 03-0375697
Entity Address, Address Line One 1 Great Valley Parkway
Entity Address, Address Line Two Suite 30
Entity Address, City or Town Malvern
Entity Address, State or Province PA
Entity Address, Postal Zip Code 19355
City Area Code 610
Local Phone Number 981-6500
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Common Stock, par value $0.001 per share
Trading Symbol PHAS
Security Exchange Name NASDAQ
Entity Emerging Growth Company true
Entity Ex Transition Period true
Amendment Flag false
Entity Central Index Key 0001169245