Investments (Gross Unrealized Losses and Fair Values of Securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	$ 99,796	$ 98,642
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	2,104	2,063
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	23,336	23,188
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	7,496	7,767
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	29,871	27,918
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss	535	598
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0	0
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss	0	0
US government agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	24,297	24,253
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	703	747
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	0	0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	0	0
Residential mortgage-backed agencies [Member]
Schedule of Investments [Line Items]
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	22,960	20,899
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss	348	279
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0	0
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss	0	0
Commercial mortgage-backed agencies [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	50,394	51,604
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	927	757
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	0	0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	0	0
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value		4,684
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss		149
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value		0
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss		0
Collateralized mortgage obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	18,445	14,706
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	370	399
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	0	0
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	0	0
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	4,491
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss	102
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss	0
Obligations of states and political subdivisions [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	6,660	8,079
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	104	160
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	2,979	2,934
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	63	91
Held-to-maturity securities, continuous unrealized loss position, less than twelve months, fair value	2,420	2,335
Held-to-maturity securities, continuous unrealized loss position, less than 12 months, unrealized loss	85	170
Held-to-maturity securities, continuous unrealized loss position, twelve months or longer, fair value	0	0
Held-to-maturity securities, continuous unrealized loss position, 12 months or longer, unrealized loss	0	0
Collateralized debt obligations [Member]
Schedule of Investments [Line Items]
Available-for-sale securities, continuous unrealized loss position, less than twelve months, fair value	0	0
Available-for-sale securities, continuous unrealized loss position, less than 12 months, unrealized losses	0	0
Available-for-sale securities, continuous unrealized loss position, twelve months or longer, fair value	20,357	20,254
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, unrealized losses	$ 7,433	$ 7,676