Asset Retirement Obligations

12 Months Ended

Dec. 31, 2011

Asset Retirement Obligation Disclosure [Abstract]

Asset Retirement Obligations

Asset Retirement Obligations

The Company's asset retirement obligations consist of legal requirements to remove certain of its network infrastructure at the expiration of the underlying right-of-way ("ROW") term and restoration requirements for leased facilities. The Company recognizes its estimate of the fair value of its asset retirement obligations in the period incurred in other long-term liabilities. The fair value of the asset retirement obligation is also capitalized as property, plant and equipment and then amortized over the estimated remaining useful life of the associated asset.

In 2011, the asset retirement obligations for certain leased facilities were primarily increased by liabilities assumed in the Global Crossing acquisition. In 2010, the asset retirement obligations for certain leased facilities were increased by an insignificant amount due to revised estimates of future obligations.

The following table provides asset retirement obligation activity for the years ended December 31, 2011 and 2010 (dollars in millions):

	2011			2010
Asset retirement obligation at January 1	$	74		$	64
Accretion expense	9			8
Liabilities assumed in Global Crossing acquisition	41			—
Liabilities settled	(2		)	(5		)
Revision in estimated cash flows	—			7
Effect of foreign currency rate change	$	(1	)	$	—
Asset retirement obligation at December 31	$	121		$	74

The balance as of January 1, 2010, activity for the year ended December 31, 2010, and balance as of December 31, 2010 have been restated to exclude the reclamation liability of the discontinued operations of the coal mining business. At December 31, 2010, the excluded reclamation liability of the discontinued operations of the coal mining business was $105 million.