Schedule II - Valuation and Qualifying Accounts (Notes)
|12 Months Ended|
Dec. 31, 2018
|SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]|
|SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]||
(1) Represents an allowance for adjustments to accounts receivable due to disputed rates, accessorial charges and other aspects of previously billed shipments.
(2) Represents uncollectible accounts written off, net of recoveries
(3) Represents adjustments to billed accounts receivable
The entire disclosure for valuation and qualifying accounts and reserves.
Reference 1: http://www.xbrl.org/2003/role/disclosureRef