Document And Entity Information	9 Months Ended
Sep. 30, 2011
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2011
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q3
Entity Registrant Name	FIRST CITIZENS BANCSHARES INC /DE/
Entity Central Index Key	0000798941
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Class A Common Stock [Member]
Entity Common Stock, Shares Outstanding	8,669,439
Class B Common Stock [Member]
Entity Common Stock, Shares Outstanding	1,639,812

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