Document and Entity Information (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Oct. 31, 2012	Jun. 30, 2011
Document and Entity Information [Abstract]
Entity Registrant Name	Capitol Bancorp Ltd.
Entity Central Index Key	0000840264
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Smaller Reporting Company
Entity Public Float			$ 5,260,254
Entity Common Stock, Shares Outstanding		41,177,979
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2012