Fair Value (Details 3) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2018	Dec. 31, 2017
Fair value measurements for financial instruments
Recorded Investment	$ 5,410	$ 5,536
Fair Value, Measurements, Nonrecurring \| Residential Real Estate
Fair value measurements for financial instruments
Recorded Investment	735	740
Fair Value, Measurements, Nonrecurring \| Consumer
Fair value measurements for financial instruments
Recorded Investment	4	2
Fair Value, Measurements, Nonrecurring \| Sales Comparison Valuation \| Residential Real Estate
Fair value measurements for financial instruments
Recorded Investment	$ 735	$ 740
Fair Value Measurements Valuation Technique(s) Description	Sales comparison	Sales comparison
Fair Value, Measurements, Nonrecurring \| Sales Comparison Valuation \| Residential Real Estate \| Minimum
Fair value measurements for financial instruments
Adjustment for differences between earning multiplier and comparable sales, Percent	(15.76%)	(15.76%)
Fair Value, Measurements, Nonrecurring \| Sales Comparison Valuation \| Residential Real Estate \| Maximum
Fair value measurements for financial instruments
Adjustment for differences between earning multiplier and comparable sales, Percent	27.92%	27.92%
Fair Value, Measurements, Nonrecurring \| Sales Comparison Valuation \| Residential Real Estate \| Weighted Average
Fair value measurements for financial instruments
Adjustment for differences between earning multiplier and comparable sales, Percent	0.53%	0.53%
Fair Value, Measurements, Nonrecurring \| Sales Comparison Valuation \| Consumer
Fair value measurements for financial instruments
Recorded Investment	$ 4	$ 2
Fair Value Measurements Valuation Technique(s) Description	Sales comparison	Sales comparison
Fair Value, Measurements, Nonrecurring \| Sales Comparison Valuation \| Consumer \| Minimum
Fair value measurements for financial instruments
Adjustment for differences between earning multiplier and comparable sales, Percent	(21.98%)	(21.98%)
Fair Value, Measurements, Nonrecurring \| Sales Comparison Valuation \| Consumer \| Maximum
Fair value measurements for financial instruments
Adjustment for differences between earning multiplier and comparable sales, Percent	21.98%	21.98%
Fair Value, Measurements, Nonrecurring \| Sales Comparison Valuation \| Consumer \| Weighted Average
Fair value measurements for financial instruments
Adjustment for differences between earning multiplier and comparable sales, Percent	0.00%	0.00%

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- Definition

Percentage of adjustment to the observed price for a similar asset or liability when an identical transaction does not exist, used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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Description of the inputs and valuation technique(s) used to measure fair value.

+ References

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- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

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