Investment Securities - Amortized cost and estimated fair value of securities with gross unrealized gains and losses (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Available-for-Sale Portfolio
Amortized cost	$ 18,494	$ 17,875
Gross unrealized gains	25	45
Gross unrealized losses	(124)	(173)
Fair Value	18,395	17,747
Held-to-Maturity Portfolio
Amortized cost	6,598	7,420
Gross unrealized gains	62	38
Gross unrealized losses	(16)	(74)
Fair Value	6,644	7,384
U.S. Government and agency obligations
Available-for-Sale Portfolio
Amortized cost	10,609	8,106
Gross unrealized gains		3
Gross unrealized losses	(80)	(110)
Fair Value	10,529	7,999
Mortgage-backed securities - residential
Available-for-Sale Portfolio
Amortized cost	7,885	9,769
Gross unrealized gains	25	42
Gross unrealized losses	(44)	(63)
Fair Value	7,866	9,748
Held-to-Maturity Portfolio
Amortized cost	655	745
Gross unrealized gains	8	13
Gross unrealized losses
Fair Value	663	758
State and Municipal securities
Held-to-Maturity Portfolio
Amortized cost	5,943	6,675
Gross unrealized gains	54	25
Gross unrealized losses	(16)	(74)
Fair Value	$ 5,981	$ 6,626

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
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Amount of accumulated unrealized gain on investments in debt securities classified as held-to-maturity.

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Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity.

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Amount before other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

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Fair value of investments in debt securities classified as held-to-maturity.

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