components of the Company's stock-based compensation (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Time lapse restricted stock:
Pre-tax compensation expense	$ 3,305	$ 3,660	$ 10,891	$ 10,030
Tax benefit	(982)	(947)	(2,728)	(2,766)
Restricted stock expense, net of tax	$ 2,323	$ 2,713	$ 8,163	$ (8,125)

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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