Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue
Sales	$ 3,207,638	$ 2,666,528	$ 8,775,720	$ 7,667,010
DIY customer [Member]
Disaggregation of Revenue
Sales	1,869,079	1,473,514	5,067,676	4,244,689
Professional service provider customer [Member]
Disaggregation of Revenue
Sales	1,264,802	1,151,721	3,510,031	3,303,987
Other sales and sales adjustments [Member]
Disaggregation of Revenue
Sales	$ 73,757	$ 41,293	$ 198,013	$ 118,334