Statements Of Consolidated Operations - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Operating Revenue	$ 4,832.4	$ 5,068.8	$ 4,865.4
Operating Expenses:
Salaries, wages and employee benefits	2,868.2	2,901.2	2,803.1
Operating expenses and supplies	878.4	1,110.7	1,116.9
Purchased transportation	561.1	590.9	512.5
Depreciation and amortization	163.7	163.6	172.3
Other operating expenses	266.1	268.8	234.4
(Gains) losses on property disposals, net	1.9	(11.9)	(2.2)
Total operating expenses	4,739.4	5,023.3	4,837.0
Operating Income	93.0	45.5	28.4
Nonoperating Expenses:
Interest expense	107.6	150.0	163.9
(Gain) loss on extinguishment of debt	0.6	(11.2)	0.0
Other, net	(10.8)	(9.5)	(6.0)
Nonoperating expenses, net	97.4	129.3	157.9
Loss before income taxes	(4.4)	(83.8)	(129.5)
Income tax benefit	(5.1)	(16.1)	(45.9)
Net Income (Loss)	0.7	(67.7)	(83.6)
Amortization of beneficial conversion feature on preferred stock	0.0	(18.1)	0.0
Net Income (Loss) Attributable to Common Shareholders	$ 0.7	$ (85.8)	$ (83.6)
Average Common Shares Outstanding - Basic	31,736	28,592	9,332
Average Common Shares Outstanding - Diluted	32,592	28,592	9,332
Earnings (Loss) Per Share - Basic	$ 0.02	$ (3.00)	$ (8.96)
Earnings (Loss) Per Share - Diluted	$ 0.02	$ (3.00)	$ (8.96)