Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Reconciliation of Federal Statutory to Actual Tax Expense:
Federal statutory income tax at 21%	$ 9,609	$ 9,091
Tax-exempt interest income	(2,267)	(2,015)
Share-based compensation	(350)	(441)
Tax-exempt earnings and gains on life insurance	(207)	(247)
Tax credits	(78)	39
Other	234	184
Actual Tax Expense	$ 6,941	$ 6,611
Federal statutory income tax rate	21.00%	21.00%
Effective Tax Rate	15.20%	15.30%

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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