Quarterly Financial Information (unaudited) (Details) - USD ($) $ / shares in Units, $ 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
Interest Income
Interest income	$ 18,920	$ 17,669	$ 17,743	$ 17,015	$ 17,464	$ 16,957	$ 16,741	$ 16,928	$ 71,347	$ 68,090	$ 64,088
Net interest income	17,463	16,230	16,299	15,618	16,123	15,396	15,242	15,498	65,610	62,259	58,931
Provision for loan and lease losses	(500)		(1,000)						(1,500)
Non-Interest Income
Non-interest income	2,880	3,344	2,583	3,407	2,061	2,806	2,271	3,001	12,214	10,139	9,575
Non-Interest Expense
Non-interest expense	12,906	12,723	13,064	12,621	12,774	12,151	11,429	11,813	51,314	48,167	54,792
Income before provision for income taxes	7,937	6,851	6,818	6,404	5,410	6,051	6,084	6,686	28,010	24,231	13,714
Net income	4,550	4,183	4,215	3,985	3,478	4,002	3,800	4,069	16,933	15,349	8,965
Dividends and accretion on preferred stock							70			70	168
Net income available to common shareholders	$ 4,550	$ 4,183	$ 4,215	$ 3,985	$ 3,478	$ 4,002	$ 3,730	$ 4,069	$ 16,933	$ 15,279	$ 8,797
Earnings Per Common Share
Basic (in dollars per share)	$ 0.13	$ 0.12	$ 0.12	$ 0.12	$ 0.10	$ 0.12	$ 0.11	$ 0.12	$ 0.49	$ 0.45	$ 0.27
Diluted (in dollars per share)	0.13	0.12	0.12	0.12	0.10	0.12	0.11	0.12	0.49	0.44	0.27
Dividends Declared Per Common Share (in dollars per share)	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.05	$ 0.24	$ 0.23	$ 0.08
Heritage Oaks Bancorp
Interest Income
Interest income									$ 20	$ 17	$ 16
Non-Interest Expense
Income before provision for income taxes									8,635	9,060	8,569
Net income									16,933	15,349	8,965
Dividends and accretion on preferred stock										70	168
Net income available to common shareholders									$ 16,933	$ 15,279	$ 8,797