Net Loss Per Common Share Attributable to Capitol Bancorp Limited (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Income loss from continuing and discontinuing operations per basic share [Abstract]
Numerator-net loss attributable to Capitol Bancorp Limited for the period	$ (5,673)	$ (22,762)	$ (23,924)	$ (38,911)
Denominator:
Weighted average number of common shares outstanding, excluding unvested restricted shares of common stock (denominator for basic and diluted net loss)	41,070,000	41,018,000	41,037,000	38,075,000
Net income (loss) per common share attributable to Capitol Bancorp Limited:
From continuing operations (in dollars per share)	$ (0.14)	$ (0.53)	$ (0.59)	$ (1.08)
From discontinued operations (in dollars per share)		(0.02)	0.01	0.06
Total net loss per common share attributable to Capitol Bancorp Limited	$ (0.14)	$ (0.55)	$ (0.58)	$ (1.02)
Stock options [Member]
Denominator:
Number of antidilutive securities excluded from diluted net loss per share computation	1,445,000	1,573,000	1,445,000	1,573,000
Unvested restricted shares [Member]
Denominator:
Number of antidilutive securities excluded from diluted net loss per share computation	9,000	26,000	9,000	26,000
Warrants [Member]
Denominator:
Number of antidilutive securities excluded from diluted net loss per share computation	1,250,000	1,326,000	1,250,000	1,326,000