Share-Based Payments - Non-vested Roll forward (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 4.85	$ 4.38
Stock Issued During Period, Value, Stock Options Exercised	$ 1,337	$ 489
Stock-based compensation expense	401	296
Compensation cost associated with ASC Topic 718	401	296
Tax benefit - stock option exercise	211	96
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Nonvested awards, total compensation cost not yet recognized, stock options	$ 1,230
Nonvested awards, total compensation cost not yet recognized, period for recognition	2 years 8 months 12 days
Additional Paid-in Capital
Share-based Compensation Arrangement by Share-based Payment Award
Stock Issued During Period, Value, Stock Options Exercised	$ 1,337	489
Compensation cost associated with ASC Topic 718	401	296
Tax benefit - stock option exercise	$ 211	$ 96

This element represents the amount of recognized equity-based compensation during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized). Alternate captions include the words "stock-based compensation".

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 35
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415241&loc=d3e4534-113899

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 20
-Section 55
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=32706628&loc=d3e11149-113907

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 20
-Section 55
-Paragraph 13
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- Definition

Amount of increase in additional paid in capital (APIC) resulting from a tax benefit associated with share-based compensation plan other than an employee stock ownership plan (ESOP). Includes, but is not limited to, excess tax benefit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 740
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6419406&loc=d3e23524-113945

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
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- Definition

Costs and payments related to employee benefits and equity-based compensation, such as pension expense and contributions, other postretirement benefits expense and payments, stock or unit options expense, and amortization of restricted stock or unit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
-Subparagraph (i)
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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

+ References

No definition available.

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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.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 2
-Subparagraph (d)(1)
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- Definition

Value of stock issued as a result of the exercise of stock options.

+ References

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-Publisher FASB
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-SubTopic 10
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-Name Accounting Standards Codification
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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30, 31
-Article 5

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-Name Regulation S-X (SX)
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