Goodwill and other intangible assets (Details) - USD ($) $ in Thousands		12 Months Ended
	Mar. 04, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Aug. 01, 2016	May 16, 2014
Finite-lived Intangible Assets [Roll Forward]
Core deposit intangible, net, beginning of period		$ 6,863
CDI current period amortization		(1,316)	$ (820)	$ (513)
Total core deposit intangible, end of period		12,317	6,863
Other Goodwill Disclosures
Goodwill		85,852	78,610
Core Deposits
Finite-Lived Intangible Assets [Line Items]
Gross core deposit intangibles balance, beginning of period			8,196	8,196
Accumulated amortization, beginning of period			(1,333)	(513)
Finite-lived Intangible Assets [Roll Forward]
Core deposit intangible, net, beginning of period		6,863	7,683
Established through acquisitions		6,770	0
CDI current period amortization		(1,316)	(820)	(500)
Total core deposit intangible, end of period		$ 12,317	$ 6,863	$ 7,683
Other Goodwill Disclosures
Core deposit intangible, useful life		10 years
Prime Pacific Financial Services
Other Goodwill Disclosures
Goodwill					$ 3,258
Bank Of America, Branch Locations
Other Goodwill Disclosures
Goodwill	$ 3,984
Bank Of America, Branch Locations | Core Deposits
Other Goodwill Disclosures
Core deposit intangible, useful life	10 years
Home Federal Bank
Other Goodwill Disclosures
Goodwill						$ 78,610