Effective Income Tax Rate Reconciliation, Bank Owned Life Insurance Earnings, Amount

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Effective Income Tax Rate Reconciliation, Deduction, Share-based Compensation, Amount

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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 increase (decrease) in the income tax rates.

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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 the disposition of a business not qualifying as a discontinued operation.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from 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 tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.

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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 income (loss) exempt from income taxes.

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Income Tax - Reconciliation of Federal Statutory to Actual Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Federal Statutory Income Tax at 35%									$ 46,758	$ 38,031	$ 31,867
Tax-exempt Interest Income									(11,127)	(8,749)	(7,083)
Basis Difference on Sale of Insurance Subsidiary											2,252
Stock Compensation									(893)	(61)	(31)
Earnings on Life Insurance									(2,302)	(1,486)	(1,012)
Tax Credits									(811)	(564)	(583)
Tax Cuts and Jobs Act - Rate Reform Impact									5,120
Other									779	438	255
Income Tax Expense	$ 15,210	$ 7,939	$ 7,207	$ 7,168	$ 7,850	$ 7,469	$ 6,716	$ 5,574	$ 37,524	$ 27,609	$ 25,665
Federal statutory income tax rate									35.00%	35.00%	35.00%