Securities - Investments in continuous unrealized loss position (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Held to Maturity, Fair Value, Less than Twelve Months		$ 3,389
Held to Maturity, Gross Unrealized Losses, Less than Twelve Months		(68)
Held to Maturity, Fair Value, Twelve Months or Greater		0
Held to Maturity, Gross Unrealized Losses, Twelve Months or Greater		0
Held to Maturity, Fair Value		3,389
Held to Maturity, Gross Unrealized Losses, Total		(68)
Fair Value, Less than Twelve Months	$ 53,486	134,167
Gross Unrealized Losses, Less than Twelve Months	(526)	(1,721)
Fair Value, Twelve Months or Greater	58,905	32,790
Gross Unrealized Losses, Twelve Months or Greater	(1,663)	(1,239)
Fair Value, Total	112,391	166,957
Gross Unrealized Losses, Total	(2,189)	(2,960)
U.S. government agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than Twelve Months	18,090	46,000
Gross Unrealized Losses, Less than Twelve Months	(99)	(304)
Fair Value, Twelve Months or Greater	5,052	4,223
Gross Unrealized Losses, Twelve Months or Greater	(64)	(76)
Fair Value, Total	23,142	50,223
Gross Unrealized Losses, Total	(163)	(380)
Obligations of states and political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Held to Maturity, Fair Value, Less than Twelve Months		1,419
Held to Maturity, Gross Unrealized Losses, Less than Twelve Months		(38)
Held to Maturity, Fair Value, Twelve Months or Greater		0
Held to Maturity, Gross Unrealized Losses, Twelve Months or Greater		0
Held to Maturity, Fair Value		1,419
Held to Maturity, Gross Unrealized Losses, Total		(38)
Fair Value, Less than Twelve Months	1,334	16,559
Gross Unrealized Losses, Less than Twelve Months	(15)	(324)
Fair Value, Twelve Months or Greater	7,432	1,082
Gross Unrealized Losses, Twelve Months or Greater	(88)	(110)
Fair Value, Total	8,766	17,641
Gross Unrealized Losses, Total	(103)	(434)
Mortgage-backed securities, Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than Twelve Months	17,246	27,627
Gross Unrealized Losses, Less than Twelve Months	(90)	(402)
Fair Value, Twelve Months or Greater	12,728	9,911
Gross Unrealized Losses, Twelve Months or Greater	(423)	(343)
Fair Value, Total	29,974	37,538
Gross Unrealized Losses, Total	(513)	(745)
Mortgage-backed securities, Non-agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than Twelve Months	5,616	7,842
Gross Unrealized Losses, Less than Twelve Months	(84)	(37)
Fair Value, Twelve Months or Greater	1,940	671
Gross Unrealized Losses, Twelve Months or Greater	(10)	(1)
Fair Value, Total	7,556	8,513
Gross Unrealized Losses, Total	(94)	(38)
Other asset backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than Twelve Months	9,206	25,399
Gross Unrealized Losses, Less than Twelve Months	(178)	(276)
Fair Value, Twelve Months or Greater	20,487	12,037
Gross Unrealized Losses, Twelve Months or Greater	(287)	(327)
Fair Value, Total	29,693	37,436
Gross Unrealized Losses, Total	(465)	(603)
Corporate securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Held to Maturity, Fair Value, Less than Twelve Months		1,970
Held to Maturity, Gross Unrealized Losses, Less than Twelve Months		(30)
Held to Maturity, Fair Value, Twelve Months or Greater		0
Held to Maturity, Gross Unrealized Losses, Twelve Months or Greater		0
Held to Maturity, Fair Value		1,970
Held to Maturity, Gross Unrealized Losses, Total		(30)
Fair Value, Less than Twelve Months	1,994	10,740
Gross Unrealized Losses, Less than Twelve Months	(60)	(378)
Fair Value, Twelve Months or Greater	11,266	4,866
Gross Unrealized Losses, Twelve Months or Greater	(791)	(382)
Fair Value, Total	13,260	15,606
Gross Unrealized Losses, Total	$ (851)	$ (760)