Investment Securities (Narrative) (Details)	3 Months Ended	15 Months Ended
	Mar. 31, 2020 USD ($) item	Mar. 31, 2020 USD ($) item security	Dec. 31, 2019 USD ($) item
Investment Securities [Line Items]
Number of holdings greater than 10 percent of stockholders equity | item	0	0	0
Held-to-maturity securities, Number of sales | security		0
Available-for-Sale Securities, Number of sales | security		0
Restricted investment securities	$ 415,868,000	$ 415,868,000	$ 382,963,000
Allowance for credit losses	0	0
Fair Value	120,138,000	120,138,000	167,833,000
Unrealized Loss	16,468,000	16,468,000	3,707,000
Fair value, 2021	45,576,000	45,576,000	93,855,000
Fair value, 2020	74,562,000	74,562,000	73,978,000
Corporate Bonds [Member]
Investment Securities [Line Items]
Fair Value	102,682,000	102,682,000	115,830,000
Unrealized Loss	$ 16,318,000	$ 16,318,000	3,170,000
Number of institutions | item	6	6
Maturity period	10 years
Fair value, 2021	$ 28,120,000	$ 28,120,000	51,020,000
Fair value, 2020	$ 74,562,000	$ 74,562,000	64,810,000
Debt securities, Weighted average fixed rate	5.14%	5.14%
State And Municipals [Member]
Investment Securities [Line Items]
Fair Value	$ 7,765,000	$ 7,765,000	11,746,000
Unrealized Loss	127,000	127,000	239,000
Fair value, 2021	7,765,000	7,765,000	6,662,000
Fair value, 2020			5,084,000
Collateralized Mortgage Obligations [Member]
Investment Securities [Line Items]
Fair Value	9,691,000	9,691,000	30,886,000
Unrealized Loss	23,000	23,000	259,000
Fair value, 2021	$ 9,691,000	$ 9,691,000	$ 30,886,000
Minimum [Member] | Corporate Bonds [Member]
Investment Securities [Line Items]
Fixed interest rate period	2 years
Maximum [Member] | Corporate Bonds [Member]
Investment Securities [Line Items]
Fixed interest rate period	3 years