Income Tax (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Reconciliation of Federal Statutory to Actual Tax Expense:
Federal statutory income tax rate	35.00%	35.00%
Federal statutory income tax at 35%	$ 10,627	$ 8,143
Tax-exempt interest income	(2,549)	(2,026)
Share-based compensation	(755)	2
Earnings on life insurance	(314)	(517)
Tax credits	(132)	(129)
Other	291	101
Actual Tax Expense	$ 7,168	$ 5,574
Effective Tax Rate	23.60%	24.00%

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

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Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other deductions.

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