Employee Stock Purchase Plan [Abstract]

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- Definition

Share-based compensation arrangement by share-based payment award, percentage of outstanding and available for grant, maximum

+ References

No definition available.

+ Details

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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=96867065&loc=d3e5047-113901

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

+ Details

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

+ References

+ Details

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

+ References

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- Definition

The aggregate cash inflow comprised of the amount received from (a) employees to acquire the entity's shares under incentive awards, including stock option exercises and restricted stock arrangements, and (b) the excess tax benefit arising from such transactions.

+ References

No definition available.

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- References

No definition available.

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- Definition

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Discount rate from fair value on purchase date that participants pay for shares.

+ References

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- References

No definition available.

+ Details

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

+ Details

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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

+ Details

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued 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

+ Details

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

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- Definition

Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

+ Details

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- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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- References

No definition available.

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

+ References

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

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- Definition

Weighted average expected volatility rate of share-based compensation awards.

+ References

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- Definition

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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No definition available.

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- References

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- Definition

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ References

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- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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- Definition

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

+ References

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- Definition

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

+ References

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- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

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- Definition

Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest options outstanding. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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- Definition

Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

+ References

No definition available.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

+ References

No definition available.

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- Definition

Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

+ References

No definition available.

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- Definition

Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

+ References

No definition available.

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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

+ References

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- Definition

The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ References

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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- Definition

Intrinsic value of equity-based compensation awards not vested. Excludes stock and unit options.

+ References

No definition available.

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- Definition

Expected term of share-based compensation awards, 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
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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Purchase price of common stock expressed as a percentage of its fair value.

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No definition available.

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- Definition

Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

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Weighted average remaining contractual term of outstanding stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

+ 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(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

Reference 3: 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(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: 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)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual percentage of outstanding shares available for grant, maximum	5.00%
Cumulative percentage of outstanding shares available for grant in a year, maximum	10.00%
Salaries, Wages and Officers' Compensation [Abstract]
Compensation expense, stock-based compensation	$ 3,370	$ 4,049	$ 2,811
Income tax benefit	$ 602	$ 1,315	$ 823
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Volatility rate	10.10%	10.30%	10.60%
Risk-free interest rate	2.70%	2.20%	1.80%
Expected dividend yield	0.70%	0.70%	0.70%
Expected life of awards (years)	9 years 2 months 12 days	8 years 10 months 24 days	9 years 6 months
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, ending balance	1,466,264
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Exercisable, ending balance	889,814
Outstanding, weighted average exercise price, ending balance		$ 13.05
Granted, weighted average exercise price	$ 19.10
Forfeited, weighted average exercise price	$ 13.29
Excess tax benefits	$ 453	$ 691	$ 1,113
Employee stock option [Member]
Salaries, Wages and Officers' Compensation [Abstract]
Compensation expense, stock-based compensation	$ 663	$ 705
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning balance	1,528,615
Granted	143,250
Exercised	(147,321)
Forfeited	58,280
Outstanding, ending balance		1,528,615
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding, weighted average exercise price, ending balance	$ 13.94
Exercised, weighted average exercise price	9.93
Exercisable, weighted average exercise price	$ 11.79
Outstanding, weighted average remaining contractual life (years)	5 years 10 months 10 days
Exercisable, weighted average remaining contractual life (years)	4 years 7 months 28 days
Unrecognized compensation cost	$ 1,393
Outstanding, aggregate intrinsic value	8,446
Exercisable, aggregate intrinisic value	$ 7,037
Number outstanding	1,466,264
Outstanding options, weighted average exercise price	$ 13.94
Number exercisable	889,814
Exercisable options, weighted average exercise price	$ 11.79
Employee stock option [Member] \| $8.00 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Lower range limit	8
Upper range limit	$ 8
Number outstanding	88,413
Weighted average remaining contractual life (years)	10 months 2 days
Outstanding options, weighted average exercise price	$ 8.00
Number exercisable	88,413
Exercisable options, weighted average exercise price	$ 8.00
Employee stock option [Member] \| $8.30 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Lower range limit	8.3
Upper range limit	$ 8.3
Number outstanding	107,000
Weighted average remaining contractual life (years)	1 year 10 months 2 days
Outstanding options, weighted average exercise price	$ 8.30
Number exercisable	107,000
Exercisable options, weighted average exercise price	$ 8.30
Employee stock option [Member] \| $11.60 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Lower range limit	11.6
Upper range limit	$ 11.6
Number outstanding	270,414
Weighted average remaining contractual life (years)	4 years 5 months 23 days
Outstanding options, weighted average exercise price	$ 11.60
Number exercisable	270,414
Exercisable options, weighted average exercise price	$ 11.60
Employee stock option [Member] \| $13.20 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Lower range limit	13.2
Upper range limit	$ 13.2
Number outstanding	284,822
Weighted average remaining contractual life (years)	5 years 6 months
Outstanding options, weighted average exercise price	$ 13.20
Number exercisable	211,422
Exercisable options, weighted average exercise price	$ 13.20
Employee stock option [Member] \| $15.05 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Lower range limit	15.05
Upper range limit	$ 15.05
Number outstanding	219,965
Weighted average remaining contractual life (years)	6 years 6 months
Outstanding options, weighted average exercise price	$ 15.05
Number exercisable	112,765
Exercisable options, weighted average exercise price	$ 15.05
Employee stock option [Member] \| $16.35 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Lower range limit	16.35
Upper range limit	$ 16.35
Number outstanding	230,800
Weighted average remaining contractual life (years)	7 years 6 months
Outstanding options, weighted average exercise price	$ 16.35
Number exercisable	77,800
Exercisable options, weighted average exercise price	$ 16.35
Employee stock option [Member] \| $17.60 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Lower range limit	17.60
Upper range limit	$ 17.60
Number outstanding	129,300
Weighted average remaining contractual life (years)	8 years 5 months 23 days
Outstanding options, weighted average exercise price	$ 17.60
Number exercisable	22,000
Exercisable options, weighted average exercise price	$ 17.60
Employee stock option [Member] \| $19.10 [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Lower range limit	19.10
Upper range limit	$ 19.10
Number outstanding	135,550
Weighted average remaining contractual life (years)	9 years 6 months
Outstanding options, weighted average exercise price	$ 19.10
Number exercisable	0
Exercisable options, weighted average exercise price	$ 19.10
Equity option [Member]
Salaries, Wages and Officers' Compensation [Abstract]
Compensation expense, stock-based compensation			596
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Vesting period	10 years
Stock Appreciation Rights (SARs) [Member]
Salaries, Wages and Officers' Compensation [Abstract]
Compensation expense, stock-based compensation	$ 540	$ 1,035	591
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Vesting period	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested, beginning balance	448,180
Granted	121,243
Forfeited	0
Vested	(188,441)
Unvested, ending balance	380,982	448,180
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Unvested, weighted average award date value, beginning balance	$ 3.10
Granted, weighted average award date value	3.84
Forfeited, weighted average award date value	0
Vested, weighted average award date value	2.93
Unvested, weighted average award date value, ending balance	$ 3.42	$ 3.10
Weighted average remaining contractual life (years)	2 years 4 months 24 days
Unrecognized compensation cost	$ 924
Aggregate intrinsic value, unvested	7,505
Restricted Stock Units (RSUs) [Member]
Salaries, Wages and Officers' Compensation [Abstract]
Compensation expense, stock-based compensation	$ 1,169	$ 1,421	897
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested, beginning balance	290,666
Granted	44,926
Forfeited	0
Vested	(87,754)
Unvested, ending balance	247,838	290,666
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Unvested, weighted average award date value, beginning balance	$ 14.41
Granted, weighted average award date value	18.55
Forfeited, weighted average award date value	0
Vested, weighted average award date value	12.94
Unvested, weighted average award date value, ending balance	$ 15.68	$ 14.41
Weighted average remaining contractual life (years)	1 year 10 months 24 days
Unrecognized compensation cost	$ 1,727
Aggregate intrinsic value, unvested	$ 4,882
Employee PRSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted	31,738
Unvested, ending balance	209,186
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Unvested, weighted average award date value, ending balance	$ 15.40
Weighted average remaining contractual life (years)	2 years 2 months 12 days
Unrecognized compensation cost	$ 1,401
Aggregate intrinsic value, unvested	$ 4,121
Nonemployee Director RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted	13,188
Unvested, ending balance	38,652
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Unvested, weighted average award date value, ending balance	$ 17.17
Weighted average remaining contractual life (years)	1 year 3 months 18 days
Unrecognized compensation cost	$ 326
Aggregate intrinsic value, unvested	761
The Davey Employee Stock Purchase Plan [Member]
Salaries, Wages and Officers' Compensation [Abstract]
Compensation expense, stock-based compensation	$ 998	$ 888	$ 727
Employee Stock Purchase Plan [Abstract]
Employee stock purchase plan, service period (in years)	1 year
Employee stock purchase plan, percentage of market price, purchase date	85.00%
Employee stock purchase, discount from market price, purchase date	15.00%