Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amortized cost and fair value of investment securities Available-for-sale [Abstract]
Amortized Cost	$ 10,169
Estimated Fair Value	10,119	$ 0
Amortized cost and fair value of investment securities held to maturity [Abstract]
Amortized Cost	54,303	62,757
Unrealized Gains	176	352
Unrealized Losses	475	282
Estimated Fair Value	54,004	62,827
Fair Value [Abstract]
Less than 12 Months, Fair Value	29,963	28,459
12 Months or More, Fair Value	14,010	0
Total, Fair Value	43,973	28,459
Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	246	282
12 Months or More, Unrealized Losses	229	0
Total, Unrealized Losses	475	282
Available for sale securities, fair value less than 12 months	10,000
Amortized Cost [Abstract]
Due in one year or less	0
Due after one through five years	10,169
Due after five years through ten years	0
Mortgage-backed securities	0
Amortized Cost	10,169
Estimated Fair Value [Abstract]
Due in one year or less	0
Due after one through five years	10,119
Due after five years through ten years	0
Mortgage-backed securities	0
Fair Value	10,119	0
Amortized Cost [Abstract]
Due in one year or less	10,011
Due after one through five years	12,020
Due after five years through ten years	1,967
Mortgage-backed securities	30,305
Amortized Cost	54,303	62,757
Estimated Fair Value [Abstract]
Due in one year or less	10,008
Due after one through five years	11,990
Due after five years through ten years	2,044
Mortgage-backed securities	29,962
Fair Value	54,004	62,827
Securities pledged as collateral	0	0
U.S. Treasury Securities [Member]
Amortized cost and fair value of investment securities held to maturity [Abstract]
Amortized Cost	4,994	12,998
Unrealized Gains	68	167
Unrealized Losses	6	0
Estimated Fair Value	5,056	13,165
Fair Value [Abstract]
Less than 12 Months, Fair Value	1,993
12 Months or More, Fair Value	0
Total, Fair Value	1,993
Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	6
12 Months or More, Unrealized Losses	0
Total, Unrealized Losses	6
Amortized Cost [Abstract]
Amortized Cost	4,994	12,998
Estimated Fair Value [Abstract]
Fair Value	5,056	13,165
U.S. Government Agency Notes [Member]
Amortized cost and fair value of investment securities Available-for-sale [Abstract]
Amortized Cost	10,169
Unrealized Gains	0
Unrealized Losses	50
Estimated Fair Value	10,119
Amortized cost and fair value of investment securities held to maturity [Abstract]
Amortized Cost	19,004	20,027
Unrealized Gains	81	133
Unrealized Losses	99	54
Estimated Fair Value	18,986	20,106
Fair Value [Abstract]
Less than 12 Months, Fair Value	6,977	5,002
12 Months or More, Fair Value	6,964	0
Total, Fair Value	13,941	5,002
Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	23	54
12 Months or More, Unrealized Losses	76	0
Total, Unrealized Losses	99	54
Amortized Cost [Abstract]
Amortized Cost	10,169
Estimated Fair Value [Abstract]
Fair Value	10,119
Amortized Cost [Abstract]
Amortized Cost	19,004	20,027
Estimated Fair Value [Abstract]
Fair Value	18,986	20,106
Mortgage-backed Securities [Member]
Amortized cost and fair value of investment securities held to maturity [Abstract]
Amortized Cost	30,305	29,732
Unrealized Gains	27	52
Unrealized Losses	370	228
Estimated Fair Value	29,962	29,556
Fair Value [Abstract]
Less than 12 Months, Fair Value	20,993	23,457
12 Months or More, Fair Value	7,046	0
Total, Fair Value	28,039	23,457
Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	217	228
12 Months or More, Unrealized Losses	153	0
Total, Unrealized Losses	370	228
Amortized Cost [Abstract]
Amortized Cost	30,305	29,732
Estimated Fair Value [Abstract]
Fair Value	$ 29,962	$ 29,556