Revenue (Tables)

12 Months Ended

Dec. 31, 2018

Revenue from Contract with Customer [Abstract]

Disaggregation of revenue

	For the Year Ended   December 31,
	2018		2017		2016
Sales to do-it-yourself customers	$	5,351,035	$	5,113,288	$	4,911,826
Sales to professional service provider customers	4,035,898		3,724,220		3,540,116
Other sales and sales adjustments	149,495		140,218		141,154
Total sales	$	9,536,428	$	8,977,726	$	8,593,096