Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2012	Dec. 31, 2011
Capitol Bancorp Limited stockholders' equity -- Notes G and L:
Preferred Stock, Shares Authorized (in shares)-Series A	700,000	700,000
Preferred Stock, Liquidation Preference Per Share (in dollars per share)-Series A	$ 100	$ 100
Preferred Stock, Shares Outstanding (in shares)-Series A	50,980	50,980
Preferred Stock, Shares Authorized for Potential Future Issuance (in shares)	19,300,000	19,300,000
Common Stock, Par or Stated Value Per Share (in dollars per share)	$ 0	$ 0
Common Stock, Shares Authorized (in shares)	1,500,000,000	1,500,000,000
Common Stock, Shares, Issued (in shares)	41,038,908	41,039,767
Common Stock, Shares, Outstanding (in shares)	41,038,908	41,039,767