DOCUMENT AND ENTITY INFORMATION	3 Months Ended
	Mar. 31, 2012	Apr. 30, 2012
Entity Registrant Name	FIRST BANKS, INC
Entity Central Index Key	0000710507
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Trading Symbol	fbspra
Entity Common Stock, Shares Outstanding		23,661
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2012
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2012