Condensed Financial Statements Of Parent Company - Condensed Statements Of Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements of Parent Company
Other income									$ 9,819	$ 6,926	$ 5,425
Salaries and employee benefits									71,471	69,526	66,008
Interest expense	$ 2,891	$ 2,907	$ 2,967	$ 2,966	$ 2,845	$ 2,810	$ 1,972	$ 1,963	11,731	9,590	8,429
Other expense									16,111	15,140	14,225
INCOME BEFORE INCOME TAXES	11,825	13,812	11,729	9,715	5,114	9,291	10,596	10,745	47,081	35,746	43,816
Provision (benefit) for income taxes									12,182	9,606	15,018
NET INCOME	$ 8,733	$ 10,269	$ 8,532	$ 7,365	$ 4,400	$ 6,954	$ 7,383	$ 7,332	34,899	26,069	29,007
CoBiz Financial Inc.
Condensed Financial Statements of Parent Company
Management fees									3,908	3,872	4,397
Dividends from bank subsidiary									8,861	8,221	8,116
Dividends from non-bank subsidiaries									1,070	2,962	1,898
Interest income									171	195	181
Other income									1,847	1,380	1,102
Total income									15,857	16,630	15,694
Salaries and employee benefits									4,147	4,518	4,408
Interest expense									7,383	5,737	4,122
Other expense									2,260	2,614	2,203
Total expenses									13,790	12,869	10,733
INCOME BEFORE INCOME TAXES									2,067	3,761	4,961
Provision (benefit) for income taxes									(2,898)	(2,751)	(1,402)
Net income (loss) before equity in undistributed earnings of subsidiaries									4,965	6,512	6,363
Equity in undistributed earnings of subsidiaries									29,934	19,557	22,644
NET INCOME									$ 34,899	$ 26,069	$ 29,007