Securities, Available-for-sale Securities (Details) Unit13 in Thousands, $ in Thousands	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months Securities		1
12 months or more securities	9	9
Total Securities	9	10
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 Months, Fair Value		$ 990
12 Months or More, Fair Value	$ 10,992	10,988
Total, Estimated Fair Value	10,992	11,978
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 Months, Unrealized Losses		5
12 Months or More, Unrealized Losses	69	95
Total, Unrealized Losses	$ 69	$ 100
U.S. Treasury Securities [Member]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
Less than 12 months Securities		1
12 months or more securities	2	1
Total Securities	2	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than 12 Months, Fair Value		$ 990
12 Months or More, Fair Value	$ 1,988	991
Total, Estimated Fair Value	1,988	1,981
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 Months, Unrealized Losses		5
12 Months or More, Unrealized Losses	7	6
Total, Unrealized Losses	$ 7	$ 11
U.S. Government Agency Notes [Member]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Number of Positions [Abstract]
12 months or more securities	7	8
Total Securities	7	8
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract]
12 Months or More, Fair Value	$ 9,004	$ 9,997
Total, Estimated Fair Value	9,004	9,997
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss [Abstract]
12 Months or More, Unrealized Losses	62	89
Total, Unrealized Losses	$ 62	$ 89