Income Taxes (Schedule of Provision for Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ 70,600	$ 77,400	$ 26,700
Foreign	2,100	6,200	9,400
State and local	22,600	15,600	10,500
Total current income tax expense	95,300	99,200	46,600
Deferred:
Federal	14,800	22,400	43,900
Foreign	(9,800)	(2,800)	3,300
State and local	2,200	(2,000)	12,300
Total deferred income tax expense	7,180	22,160	56,209
Provision for income taxes	102,465	116,843	106,072
Continuing Operations [Member]
Deferred:
Total deferred income tax expense	$ 7,200	$ 17,600	$ 59,500