Note 24 - Parent Company Financial Statements - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash	$ 80,604	$ 47,365	$ 66,970
Merchants Bank of Commerce	188,459	143,078
Investment in Bank of Commerce Holdings Trust II	310	310
Other assets	28,553	22,485
Total Assets	1,479,616	1,307,104
Junior subordinated debentures	10,310	10,310
Total	17,700	13,352
Total liabilities	1,305,138	1,168,783
Total liabilities and shareholders’ equity	1,479,616	1,307,104
Parent Company [Member]
Cash	6,814	19,425
Bank of Commerce Mortgage	(64)	(64)
Investment in Bank of Commerce Holdings Trust II	310	310
Other assets	423	157
Total Assets	195,942	162,906
Senior debt, net		3,494
Subordinated debt, net	9,957	9,911
Junior subordinated debentures	10,310	10,310
Total	1,197	870
Total liabilities	21,464	24,585
Shareholders’ equity	174,478	138,321
Total liabilities and shareholders’ equity	$ 195,942	$ 162,906