REVENUES (Freight & Delivery Revenues) (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Total revenues		$ 1,088,047	$ 1,240,197	$ 1,200,151	$ 854,474	$ 977,490	$ 1,094,715	$ 1,030,763	$ 787,328	$ 4,382,869	[1]	$ 3,890,296	[1]	$ 3,592,667	[1]
Freight & Delivery Revenues [Member]
Disaggregation of Revenue [Line Items]
Total revenues	[2]									(641,815)		(528,916)		(535,929)
Total Revenues Excluding Freight & Delivery [Member]
Disaggregation of Revenue [Line Items]
Total revenues										$ 3,741,054		$ 3,361,380		$ 3,056,738

[1] The geographic markets are defined by states/countries as follows:East market - Arkansas, Delaware, Illinois, Kentucky, Maryland, North Carolina, Pennsylvania, Tennessee, Virginia, and Washington D.C.Gulf Coast market - Alabama, Florida, Georgia, Louisiana, Mexico, Mississippi, Oklahoma, South Carolina, Texas and the BahamasWest market - Arizona, California and New Mexico

[2] Includes freight & delivery to remote distribution sites.