Share-Based Compensation - Components of Share-Based Compensation Awards (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	$ 1,062	$ 891	$ 2,887	$ 2,546
Income tax benefit	(226)	(217)	(1,008)	(1,105)
Total share-based compensation expense, net of income taxes	836	674	1,879	1,441
Stock and ESPP Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	36	39	72	88
Income tax benefit	0	(15)	(57)	(153)
Total share-based compensation expense, net of income taxes	36	24	15	(65)
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense	1,026	852	2,815	2,458
Income tax benefit	(226)	(202)	(951)	(952)
Total share-based compensation expense, net of income taxes	$ 800	$ 650	$ 1,864	$ 1,506

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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