Asset Retirement Obligations (Tables)
 3 Months Ended
Mar. 31, 2015
Asset Retirement Obligation [Abstract]  
Changes In Company's Liability For Asset Retirement Obligations
(in millions)
2015
 
2014
 
 
 
Predecessor
Balance as of January 1,
$
23.2

 
$
26.3

Noncontributed net parent investment adjustments(1)
(0.4
)
 
—

Accretion expense
0.3

 
0.4

Additions
—

 
—

Settlements
—

 
—

Change in estimated cash flows
—

 
—

Balance as of March 31,
$
23.1

 
$
26.7


(1) Reflects the removal of amounts related to Crossroads Pipeline Company, which was included in the Predecessor but was not contributed to the Partnership.
The asset retirement obligations above relate to obligations related to the modernization program of pipelines and transmission facilities, the retiring of offshore facilities, PCB remediation and asbestos removal at several compressor and measuring stations. The Partnership recognizes that there are obligations to incur significant costs to retire wells associated with gas storage operations; however, the lives of these wells are indeterminable until management establishes plans for closure.