Share-Based Compensation - Components of Awards (Details) - 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]
Pre-tax compensation expense	$ 3,592	$ 2,827	$ 2,600
Income tax expense (benefit)	(1,276)	(1,883)	(865)
Total share-based compensation expense, net of income taxes	2,316	944	1,735
Stock and ESPP Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	109	121	76
Income tax expense (benefit)	(97)	(322)	18
Total share-based compensation expense, net of income taxes	12	(201)	94
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	3,483	2,706	2,524
Income tax expense (benefit)	(1,179)	(1,561)	(883)
Total share-based compensation expense, net of income taxes	$ 2,304	$ 1,145	$ 1,641

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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