Document And Entity Information (USD $)	12 Months Ended
	Dec. 31, 2013	Feb. 18, 2014	Jun. 30, 2013
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2013
Document Fiscal Year Focus	2013
Document Fiscal Period Focus	FY
Trading Symbol	zion
Entity Registrant Name	ZIONS BANCORPORATION /UT/
Entity Central Index Key	0000109380
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 5,196,248,111
Entity Common Stock, Shares Outstanding		184,870,116