Asset Retirement Obligations

6 Months Ended

Jun. 30, 2013

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations

Note 5 – Asset Retirement Obligations

The change in our asset retirement obligations during the six months ended June 30, 2013 is set forth below:

	Six Months Ended June  30, 2013
	(in millions)
Asset retirement obligations as of the beginning of the period, including current portion	$	488.3
Liabilities incurred		16.5
Liabilities settled		(37.3	)
Accretion expense		16.6
Asset retirement obligations as of the end of the period, including current portion	$	484.1