Principles of Consolidation (Tables)
 12 Months Ended
Dec. 31, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Undiscounted Amounts And Material Changes In Insurance Claims [Table Text Block]
Expected aggregate undiscounted amounts and material changes to these amounts as of December 31 are presented below:

(in millions)
Workers'
Compensation
Property Damage and Liability Claims
Total
Undiscounted amount at December 31, 2011
$
449.6

$
79.9

$
529.5

Estimated settlement cost for 2012 claims
100.4

27.4

127.8

Claim payments, net of recoveries
(140.9
)
(43.7
)
(184.6
)
Change in estimated settlement cost for older claim years
(19.0
)
1.5

(17.5
)
Undiscounted amount at December 31, 2012
$
390.1

$
65.1

$
455.2

Estimated settlement cost for 2013 claims
89.2

36.7

125.9

Claim payments, net of recoveries
(115.6
)
(24.3
)
(139.9
)
Change in estimated settlement cost for older claim years
(16.7
)
(8.7
)
(25.4
)
Undiscounted settlement cost estimate at December 31, 2013
$
347.0

$
68.8

$
415.8

Discounted settlement cost estimate at December 31, 2013
$
316.6

$
68.2

$
384.8
Estimated Cash Payments To Settle Claims [Table Text Block]
Estimated cash payments to settle claims which were incurred on or before December 31, 2013, for the next five years and thereafter are as follows:

(in millions)
Workers'
Compensation
Property Damage and Liability Claims
Total
2014
$
84.3

$
23.2

$
107.5

2015
59.0

18.6

77.6

2016
41.5

13.7

55.2

2017
30.2

6.9

37.1

2018
22.8

3.9

26.7

Thereafter
109.2

2.5

111.7

Total
$
347.0

$
68.8

$
415.8
Property, Plant and Equipment [Table Text Block]
The following is a summary of the components of our property and equipment at cost as of December 31:

(in millions)
2013
 
2012
Land
$
267.8

 
$
269.6

Structures
810.4

 
825.8

Revenue equipment
1,438.3

 
1,442.8

Technology equipment and software
133.9

 
127.0

Other
193.8

 
203.8

Total cost
$
2,844.2

 
$
2,869.0
Schedule of Service Lives for Property, Plant and Equipment [Table Text Block]
We carry property and equipment at cost less accumulated depreciation. We compute depreciation using the straight-line method based on the following service lives:

 
Years
Structures
10 - 30
Revenue equipment
10 - 20
Technology equipment and software
3 - 7
Other
3 - 10
Schedule of Equity Method Investments [Table Text Block]
The following reflects the components of these results for the years ended December 31:

(in millions)
2013
2012
2011
Our share of joint venture earnings
$
(2.1
)
$
(1.9
)
$
(2.7
)
Impairment charge
—

30.8

—

Net equity method (earnings) losses
$
(2.1
)
$
28.9

$
(2.7
)
Fair Value, Assets Measured on Recurring Basis [Table Text Block]
The following tables summarize the fair value hierarchy of our financial assets held at fair value on a recurring basis, which consists of our restricted cash held in escrow:

 
 
 
Fair Value Measurement at December 31, 2013
(in millions)
Total Carrying
Value
 
Quoted prices
in active market
(Level 1)
 
Significant
other
observable
inputs (Level 2)
 
Significant
unobservable
inputs
(Level 3)
Restricted amounts held in escrow-current
$
90.1

 
$
90.1

 
$
—

 
$
—

Restricted amounts held in escrow-long term
0.6

 
0.6

 
—

 
—

Total assets at fair value
$
90.7

 
$
90.7

 
$
—

 
$
—



 
 
 
Fair Value Measurement at December 31, 2012
(in millions)
Total Carrying
Value
 
Quoted prices
in active market
(Level 1)
 
Significant
other
observable
inputs (Level 2)
 
Significant
unobservable
inputs
(Level 3)
Restricted amounts held in escrow-current
$
20.0

 
$
20.0

 
$
—

 
$
—

Restricted amounts held in escrow-long term
102.5

 
102.5

 
—

 
—

Total assets at fair value
$
122.5

 
$
122.5

 
$
—

 
$
—