Summary of Significant Accounting Policies Summary of Significant Accounting Policies (SIP) (Details) - shares	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares to be issued in stock incentive plan (in shares)	149,983
Options, Grants in Period, Gross	0	0	0
RSA/RSU, Grants in Period, Gross	28,700	18,391	13,912
Employee Discount for Employee Stock Purchase Plan	5.00%
Employee Stock Purchase Plan, Number Of Shares Authorized	600,000
Stock Unit Awards and Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSA/RSU, Grants in Period, Gross			13,912
Stock Unit Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSA/RSU, Grants in Period, Gross	28,700	18,391

Employee Discount for Employee Stock Purchase Plan

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- Definition

Employee Stock Purchase Plan, Number Of Shares Authorized

+ References

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

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