Revenue (Tables)

9 Months Ended

Sep. 30, 2018

Revenue from Contract with Customer [Abstract]

Disaggregation of revenue

	For the Three Months Ended   September 30,				For the Nine Months Ended   September 30,
	2018		2017		2018		2017
Sales to do-it-yourself customers	$	1,408,140	$	1,342,727	$	4,053,137	$	3,867,771
Sales to professional service provider customers	1,040,728		960,421		3,058,127		2,812,602
Other sales and sales adjustments	33,849		36,682		110,207		106,545
Total sales	$	2,482,717	$	2,339,830	$	7,221,471	$	6,786,918