Income Taxes (Summary of Income Before Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
United States operations									$ 138,426	$ (456,403)	$ 106,222
Foreign and U.S. territory operations									35,853	30,569	26,391
INCOME (LOSS) BEFORE INCOME TAXES	$ 53,212	$ 49,360	$ 40,435	$ 31,272	$ (106,717)	$ 32,312	$ (358,339)	$ 6,910	$ 174,279	$ (425,834)	$ 132,613