Schedule II - Valuation and Qualifying Accounts (Notes)
|12 Months Ended|
Dec. 31, 2017
|Valuation and Qualifying Accounts [Abstract]|
|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 any allowance and reserve accounts (their beginning and ending balances, as well as a reconciliation by type of activity during the period). Alternatively, disclosure of the required information may be within the footnotes to the financial statements or a supplemental schedule to the financial statements.
Reference 1: http://www.xbrl.org/2003/role/presentationRef