Income Taxes - Reconciliation of the Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income tax expense computed at statutory rate	$ 27,129	$ 17,872	$ 20,981
Increases (decreases) resulting from:
State income taxes, net of federal tax benefit	4,985	4,902	1,936
Federal jobs credits	(3,089)	(3,164)	(5,006)
Tax exempt interest	(323)	(399)	(384)
Share-based compensation	1,323	298	(1,179)
Other, net	479	1,006	38
Tax provision	$ 30,504	$ 20,515	$ 16,386

Effective Income Tax Rate Reconciliation Increases (Decreases)

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Amount of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to expense for award under share-based payment arrangement. Excludes expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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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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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 noncontrolling interest income (loss) exempt from income taxes.

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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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