Income Taxes (Summary of Income Before Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Abstract]
United States operations									$ 106,222	$ 135,177	$ 128,072
Foreign and U.S. territory operations									26,391	18,798	21,043
INCOME BEFORE INCOME TAXES	$ 75,152	$ 32,804	$ 39,867	$ (15,210)	$ 45,193	$ 34,396	$ 52,516	$ 21,870	$ 132,613	$ 153,975	$ 149,115

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

+ References

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The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

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