Share-Based Compensation - Components of Awards (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	$ 1,217	$ 1,135	$ 3,615	$ 3,568
Income tax expense (benefit)	(136)	149	(711)	(373)
Total share-based compensation expense, net of income taxes	1,081	1,284	2,904	3,195
Stock and ESPP Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	16	23	131	76
Income tax expense (benefit)	0	0	(92)	(29)
Total share-based compensation expense, net of income taxes	16	23	39	47
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	1,201	1,112	3,484	3,492
Income tax expense (benefit)	(136)	149	(619)	(344)
Total share-based compensation expense, net of income taxes	$ 1,065	$ 1,261	$ 2,865	$ 3,148

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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