Investment Securities (Held-to-maturity Securities with Unrealized Loss) (Details) $ in Thousands	Jun. 30, 2018 USD ($) securities	Dec. 31, 2017 USD ($) securities
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 months, fair value	$ 11,258	$ 1,476
Less than 12 months, unrealized loss	$ 107	$ 4
Less than 12 months, no. of securities | securities	5	2
12 months or more, fair value	$ 15,058	$ 16,667
12 months or more, unrealized loss	$ 923	$ 587
12 months or more, no. of securities | securities	4	4
Total fair value	$ 26,316	$ 18,143
Total unrealized loss	1,030	591
States and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Total unrealized loss	0	0
Residential mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 months, fair value	11,258	1,476
Less than 12 months, unrealized loss	$ 107	$ 4
Less than 12 months, no. of securities | securities	5	2
12 months or more, fair value	$ 11,511	$ 12,098
12 months or more, unrealized loss	$ 834	$ 525
12 months or more, no. of securities | securities	3	3
Total fair value	$ 22,769	$ 13,574
Total unrealized loss	941	529
Commercial mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 months, fair value	0	0
Less than 12 months, unrealized loss	$ 0	$ 0
Less than 12 months, no. of securities | securities	0	0
12 months or more, fair value	$ 3,547	$ 4,569
12 months or more, unrealized loss	$ 89	$ 62
12 months or more, no. of securities | securities	1	1
Total fair value	$ 3,547	$ 4,569
Total unrealized loss	$ 89	$ 62