Fair Values of Assets and Liabilities (Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	$ 375,929	$ 350,040	[1]
US Government-sponsored Enterprises Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	2,019	2,044
Residential mortgage-backed securities - GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	288,141	290,145
Residential mortgage-backed securities - Private [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	15,083	17,271
Commercial mortgage-backed securities - GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	22,148	21,958
Commercial mortgage-backed securities - Private [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	17,813	10,215
Corporate notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	30,725	8,407
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Level 1 [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	375,929	350,040
Level 2 [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	(1,359)
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Level 3 [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	0
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Mortgage servicing rights	0	0
Total assets at fair value	0	0
Recurring [Member] | Level 1 [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	0	0
Recurring [Member] | Level 1 [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 1 [Member] | Residential mortgage-backed securities - GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 1 [Member] | Residential mortgage-backed securities - Private [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 1 [Member] | Commercial mortgage-backed securities - GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 1 [Member] | Commercial mortgage-backed securities - Private [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 1 [Member] | Corporate notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	375,929	350,040
Mortgage servicing rights	0	0
Total assets at fair value	374,570	349,515
Recurring [Member] | Level 2 [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	(1,359)	(525)
Recurring [Member] | Level 2 [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	2,019	2,044
Recurring [Member] | Level 2 [Member] | Residential mortgage-backed securities - GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	288,141	290,145
Recurring [Member] | Level 2 [Member] | Residential mortgage-backed securities - Private [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	15,083	17,271
Recurring [Member] | Level 2 [Member] | Commercial mortgage-backed securities - GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	22,148	21,958
Recurring [Member] | Level 2 [Member] | Commercial mortgage-backed securities - Private [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	17,813	10,215
Recurring [Member] | Level 2 [Member] | Corporate notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	30,725	8,407
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Mortgage servicing rights	2,108	1,726
Total assets at fair value	2,108	1,726
Recurring [Member] | Level 3 [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	0	0
Recurring [Member] | Level 3 [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 3 [Member] | Residential mortgage-backed securities - GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 3 [Member] | Residential mortgage-backed securities - Private [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 3 [Member] | Commercial mortgage-backed securities - GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 3 [Member] | Commercial mortgage-backed securities - Private [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Recurring [Member] | Level 3 [Member] | Corporate notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	0	0
Total [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	375,929	350,040
Total [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	(1,359)
Total [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	375,929	350,040
Mortgage servicing rights	2,108	1,726
Total assets at fair value	376,678	351,241
Total [Member] | Recurring [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative assets	(1,359)	(525)
Total [Member] | Recurring [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	2,019	2,044
Total [Member] | Recurring [Member] | Residential mortgage-backed securities - GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	288,141	290,145
Total [Member] | Recurring [Member] | Residential mortgage-backed securities - Private [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	15,083	17,271
Total [Member] | Recurring [Member] | Commercial mortgage-backed securities - GSE [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	22,148	21,958
Total [Member] | Recurring [Member] | Commercial mortgage-backed securities - Private [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	17,813	10,215
Total [Member] | Recurring [Member] | Corporate notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available-for-sale securities	$ 30,725	$ 8,407

[1] Derived from audited consolidated financial statements