XML 73 R31.htm IDEA: XBRL DOCUMENT v3.8.0.1
Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2017
Accounting Policies [Abstract]  
Net gain on disposition of assets
The following table presents the net gain on asset dispositions for the years ending December 31 (in millions):
 
2017
 
2016
 
2015
Net disposition gains
$
44.1

 
$
49.7

 
$
90.3

Residual sharing income
10.2

 
83.6

 
13.4

Non-remarketing net disposition gains
8.4

 
3.2

 
9.4

Asset impairment losses (1)
(8.6
)
 
(38.5
)
 
(33.9
)
Net Gain on Asset Dispositions
$
54.1

 
$
98.0

 
$
79.2