Earnings Per Share (Details) - shares	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Earnings Per Share [Abstract]
Weighted average shares used in basic computations (in shares)	42,893,498	42,865,407	42,886,867	40,084,730
Dilutive effect of stock options and restricted stock units (in shares)	16,519	13,912	16,921	210
Weighted average shares used in diluted computations (in shares)	42,910,017	42,879,319	42,903,788	40,084,940
Antidilutive securities excluded from computation of weighted average common shares (in shares)	66,000	83,000		96,000	177,000

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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- Definition

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
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- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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