Segment Information - Disaggregated Geographical Revenue by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 5,015,023	$ 4,722,922	$ 14,686,116	$ 14,131,281
North America
Disaggregation of Revenue [Line Items]
Net sales	4,058,810	3,992,020	12,110,118	11,827,213
Australasia
Disaggregation of Revenue [Line Items]
Net sales	403,952	298,797	975,222	903,600
Automotive Parts | North America
Disaggregation of Revenue [Line Items]
Net sales	1,942,922	1,918,814	5,720,290	5,646,108
Automotive Parts | Australasia
Disaggregation of Revenue [Line Items]
Net sales	295,424	298,797	866,694	903,600
Automotive Parts | Europe
Disaggregation of Revenue [Line Items]
Net sales	552,261	432,105	1,600,776	1,400,468
Industrial Parts | North America
Disaggregation of Revenue [Line Items]
Net sales	1,624,303	1,577,329	4,941,447	4,727,938
Industrial Parts | Australasia
Disaggregation of Revenue [Line Items]
Net sales	108,528	0	108,528	0
Business Products | North America
Disaggregation of Revenue [Line Items]
Net sales	$ 491,585	$ 495,877	$ 1,448,381	$ 1,453,167