Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 5,100	$ 2,800
Interest and penalties	$ 0	$ 0
Effective income tax rate (as percent)	19.70%	19.00%
Federal and State income tax statutory rate (as percent)	26.14%	26.14%
Excess tax benefit	$ 769	$ 2,700

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 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 excess tax benefit for share-based compensation cost.

+ References

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The sum of the amounts of estimated penalties and interest recognized in the period arising from income tax examinations.

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Amount of unrecognized tax benefits.

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