Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2016	Apr. 30, 2016
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2016
Document Period End Date	Mar. 31, 2016
Current Fiscal Year End Date	--12-31
Entity Registrant Name	CommunityOne Bancorp
Entity Central Index Key	0000764811
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		24,292,958