Segments (Schedule of net sales, adjusted EBITDA and certain other measures by reportable segment) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Net sales	$ 1,090,343	$ 964,249	$ 2,991,118	$ 2,736,029
Gross profit	273,082	254,767	763,032	716,666
Depreciation & amortization	20,453	18,535	60,747	52,959
Operating segments [Member] | Geographic divisions [Member]
Segment Reporting Information [Line Items]
Net sales	1,090,343	964,249	2,991,118	2,736,029
Gross profit	273,082	254,767	763,032	716,666
Depreciation & amortization	19,941	17,974	59,218	51,121
Adjusted EBITDA	114,149	96,752	300,991	260,537
Other reconciling items [Member] | Other reconciling items [Member]
Segment Reporting Information [Line Items]
Net sales	0	0	0	0
Gross profit	0	0	0	0
Depreciation & amortization	512	561	1,529	1,838
Adjusted EBITDA	$ (14,961)	$ (22,094)	$ (50,448)	$ (58,150)