Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest income:
Interest and fees on loans		$ 11,164	$ 9,758	$ 21,893	$ 19,142
Interest on taxable securities		1,278	872	2,487	1,661
Interest on tax-exempt securities		413	534	876	1,064
Interest on interest-bearing deposits in other banks		135	156	264	270
Total interest income		12,990	11,320	25,520	22,137
Interest expense:
Interest on demand deposits		215	184	436	332
Interest on savings deposits		64	47	123	94
Interest on certificates of deposit		488	545	983	1,074
Interest on Federal Home Loan Bank of San Francisco borrowings		267	3	314	3
Interest on other borrowings		279	295	560	588
Interest on junior subordinated debentures		97	71	179	137
Total interest expense		1,410	1,145	2,595	2,228
Net interest income		11,580	10,175	22,925	19,909
Provision for loan and lease losses			300		500
Net interest income after provision for loan and lease losses		11,580	9,875	22,925	19,409
Noninterest income:
Fees on payroll and benefit processing		146	147	315	338
Life insurance		127	135	256	781
Gain on sale of investment securities, net		4	35	40	101
Federal Home Loan Bank of San Francisco dividends		95	54	175	157
Gain (loss) on sale of OREO			12	16	(59)
Other income		115	182	225	325
Total noninterest income		962	995	1,944	2,466
Noninterest expense:
Salaries and related benefits		4,513	4,147	9,368	9,005
Premises and equipment		1,016	1,054	2,087	2,102
Federal Deposit Insurance Corporation insurance premium		93	104	189	152
Data processing fees		471	451	903	857
Professional service fees		314	459	659	843
Telecommunications		178	223	394	434
Other expenses		1,086	1,288	2,104	2,323
Total noninterest expense		7,671	7,726	15,704	15,716
Income before provision for income taxes		4,871	3,144	9,165	6,159
Provision for income taxes		1,253	935	2,306	1,698
Net income		$ 3,618	$ 2,209	$ 6,859	$ 4,461
Earnings per share - basic (in dollars per share)		$ 0.22	$ 0.15	$ 0.42	$ 0.31
Weighted average shares - basic (in shares)	[1]	16,245	15,014	16,237	14,220
Earnings per share - diluted (in dollars per share)		$ 0.22	$ 0.15	$ 0.42	$ 0.31
Weighted average shares - diluted (in shares)		16,325	15,113	16,319	14,321
Deposit Account [Member]
Noninterest income:
Revenue from Contract with Customer		$ 175	$ 142	$ 351	$ 269
Credit and Debit Card [Member]
Noninterest income:
Revenue from Contract with Customer		$ 300	$ 288	$ 566	$ 554

[1] Excludes unvested restricted shares because they do not have dividend or voting rights