Business Segment Information (Reconciliation of Total Operating Profit) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Total operating profit from segments	$ 117,703	$ 136,709	$ 245,914	$ 260,305
Income from operations	100,312	120,136	210,540	223,697
Operating Segments
Segment Reporting Information [Line Items]
Total operating profit from segments	117,703	136,709	245,914	260,305
Corporate
Segment Reporting Information [Line Items]
Corporate overhead expenses	$ (17,391)	$ (16,573)	$ (35,374)	$ (36,608)