Segments and Related Information (Reconciliation of Consolidated Income before Income Taxes to EBITDA) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
EBITDA Reconciliation:
Income before income taxes	$ 77,565	$ 159,959	$ 114,050	$ 215,100
Interest expense, net	14,808	16,623	31,812	38,881
Depreciation	57,687	55,279	110,776	109,504
Amortization of intangible assets	9,793	4,665	17,184	9,471
EBITDA	$ 159,900	$ 236,500	$ 273,800	$ 373,000