Document and Entity Information	12 Months Ended
	Mar. 01, 2013
Risk/Return:
Document Type	485BPOS
Document Period End Date	Dec. 31, 2012
Registrant Name	FIDELITY HASTINGS STREET TRUST
Central Index Key	0000035348
Amendment Flag	false
Document Creation Date	Feb. 28, 2013
Document Effective Date	Mar. 01, 2013
Prospectus Date	Mar. 01, 2013