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.

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- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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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

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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- Definition

Total number of shares issued during the period, including shares forfeited, as a result of Restricted Stock Awards.

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Compensation Plans (Restricted Stock Units) (Details) - Restricted Stock Units (RSUs) [Member] - USD ($) $ 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]
Restricted stock units issued	172,000	114,000	62,000
Vesting period of compensation expense not yet recognized	2 years 11 days
2017 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense recognized		$ 1,200
Unrecognized compensation expense		$ 4,300
2017 Grants [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of compensation expense not yet recognized		24 months
2017 Grants [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of compensation expense not yet recognized		26 months
2018 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense recognized	$ 2,200
Unrecognized compensation expense	$ 8,100
2018 Grants [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of compensation expense not yet recognized	24 months
2018 Grants [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of compensation expense not yet recognized	26 months
2016 Grants [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense recognized			$ 800
Unrecognized compensation expense			$ 3,400
2016 Grants [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of compensation expense not yet recognized			24 months
2016 Grants [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of compensation expense not yet recognized			28 months