Revenue Recognition - Schedule of Disaggregated Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation Of Revenue [Line Items]
Revenue	$ 1,254,222	$ 1,260,656	$ 2,494,378	$ 2,530,038
Janitorial, foodservice and breakroom supplies (JanSan products) [Member]
Disaggregation Of Revenue [Line Items]
Revenue	346,305	349,700	674,809	695,127
Technology products [Member]
Disaggregation Of Revenue [Line Items]
Revenue	298,801	309,689	613,621	626,900
Traditional office products [Member]
Disaggregation Of Revenue [Line Items]
Revenue	176,617	186,708	355,568	384,740
Industrial supplies [Member]
Disaggregation Of Revenue [Line Items]
Revenue	163,031	146,104	318,241	293,303
Cut sheet paper products [Member]
Disaggregation Of Revenue [Line Items]
Revenue	116,020	109,631	235,587	215,795
Automotive products [Member]
Disaggregation Of Revenue [Line Items]
Revenue	85,389	82,143	166,381	160,949
Office furniture [Member]
Disaggregation Of Revenue [Line Items]
Revenue	62,997	69,939	121,798	142,027
Other revenues [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 5,062	$ 6,742	$ 8,373	$ 11,198