Securities (Narrative) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Jan. 31, 2018
Schedule of Trading Securities and Other Trading Assets [Line Items]
Asset-backed securities pledged to secure certain deposits	$ 45,500,000	$ 41,300,000
Asset-backed securities pledged as collateral	0	3,300,000
Amount	223,895,000	216,247,000
Amortized cost, available for sale	129,053,000	122,524,000
Other-than temporary impairment charges	0	0
Sale of securities	0	0	$ 34,900,000
Securities held to maturity (HTM), at amortized cost	95,495,000	96,271,000
Securities available for sale (AFS), at fair value	128,400,000	119,976,000
Fair value of securities of unrealized losses from amortized cost	62,329,000	84,941,000
Unrealized losses	1,453,000	2,757,000
Held-to-maturity Securities, Fair Value, Total	94,565,000	93,745,000
Fair value of securities of unrealized losses from amortized cost	65,003,000	83,047,000
Total, unrealized losses	1,273,000	2,672,000
Gross unrealized losses, available for sale	1,453,000	2,757,000
Gross unrealized losses, held to maturity	1,273,000	2,672,000
Residential Mortgage Backed Securities Issued By US Government Sponsored Enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amortized cost, available for sale	12,343,000	7,641,000
Securities held to maturity (HTM), at amortized cost	25,191,000	25,948,000
Securities available for sale (AFS), at fair value	12,244,000	7,361,000
Held-to-maturity Securities, Fair Value, Total	25,123,000	25,267,000
Gross unrealized losses, available for sale	126,000	281,000
Gross unrealized losses, held to maturity	192,000	756,000
Residential Collateralized Mortgage Obligations, Issued By US Government Sponsored Enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amortized cost, available for sale	104,772,000	102,411,000
Securities held to maturity (HTM), at amortized cost	52,074,000	52,375,000
Securities available for sale (AFS), at fair value	104,512,000	100,740,000
Held-to-maturity Securities, Fair Value, Total	51,420,000	51,079,000
Gross unrealized losses, available for sale	1,014,000	1,870,000
Gross unrealized losses, held to maturity	$ 842,000	$ 1,360,000
Asset-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Held to maturity securities with unrealized losses, average life	3 years 10 months 24 days	4 years 10 months 17 days
Securities held to maturity (HTM), at amortized cost	$ 64,600,000	$ 82,600,000
Fair value of securities of unrealized losses from amortized cost	62,329,000	84,941,000
Unrealized losses	1,453,000	2,757,000
Fair value of securities of unrealized losses from amortized cost	59,581,000	77,707,000
Total, unrealized losses	$ 1,223,000	$ 2,521,000
Asset-backed Securities, Issued by Private Enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Held to maturity securities with unrealized losses, average life	3 years 2 months 9 days	3 years 4 days
Held to maturity securities with unrealized losses, average duration	2 years 7 months 24 days	2 years 3 months 29 days
Fair value of securities of unrealized losses from amortized cost	$ 446,000	$ 441,000
Total, unrealized losses	$ 19,000	$ 41,000
Asset Backed Securities Or Bonds Issued By Us Government Sponsored Enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Held to maturity securities with unrealized losses, average duration	3 years 5 months 27 days	4 years 3 months 4 days
Asset-backed securities issued by GSEs [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Available for sale securities, average life	4 years 1 month 21 days	4 years 4 months 13 days
Available for sale securities, average duration	3 years 8 months 5 days	3 years 10 months 10 days
Held to maturity securities, average life	4 years 6 months 15 days	4 years 10 months 17 days
Held to maturity securities, average duration	3 years 11 months 27 days	4 years 3 months
Available for sale securities with unrealized losses, average life	4 years 2 months 23 days	4 years 3 months 26 days
Available for sale securities with unrealized losses, average duration	3 years 9 months 11 days	3 years 9 months 29 days
Residential Collateralized Mortgage Obligations, Issued By Private Enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Securities held to maturity (HTM), at amortized cost	$ 465,000	$ 483,000
Held-to-maturity Securities, Fair Value, Total	446,000	442,000
Gross unrealized losses, held to maturity	19,000	41,000
US Government Obligations [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Securities held to maturity (HTM), at amortized cost	1,489,000	999,000
Held-to-maturity Securities, Fair Value, Total	1,488,000	998,000
Gross unrealized losses, held to maturity	$ 1,000	$ 1,000
Standard Poor's, AAA Rating [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Percentage of asset backed securities in investment portfolio	99.00%	99.00%
Amount	$ 223,430,000	$ 215,764,000
Standard Poor's, BB Rating [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Amount	$ 465,000	$ 483,000