Stock-Based Compensation (Details 5) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Stock-based compensation
Shares tendered by employees to pay employee withholding taxes (in shares)			205,500
Compensation expense, net of forfeitures, and related tax effects recognized in connection with nonvested shares
Compensation expense	$ 4,170	$ 3,837	$ 12,492	$ 11,269
Income tax benefit	792	$ 713	2,347	2,098
Nonvested shares
Stock-based compensation
Total fair value of shares vested			24,900	$ 75,200
Total unrecognized compensation expense	$ 21,500		$ 21,500
Expected weighted average period for recognition of expense			2 years

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

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