Commitments and Contingencies

12 Months Ended

Dec. 31, 2014

Commitments and Contingencies [Abstract]

Commitments and Contingencies

Commitments and Contingencies

The Company is involved in various claims, lawsuits, or proceedings arising in the ordinary course of business. While there are uncertainties inherent in the ultimate outcome of such matters and it is impossible to presently determine the ultimate costs or losses that may be incurred, if any, management believes the resolution of such uncertainties and the incurrence of such costs should not have a material adverse effect on the Company's consolidated financial position or results of operations. Additionally, the Company and certain of its subsidiaries are contingently liable for commitments or performance guarantees arising in the ordinary course of business, including certain letters of credit or surety bonds. See note 14 for a discussion of the operating lease commitments. In addition, see note 1 for a discussion of the Company's option to purchase approximately 53% of its towers at the end of their respective lease terms. The Company has no obligation to exercise such purchase options.

Asset Retirement Obligations

Pursuant to its ground lease and easement agreements, the Company has the obligation to perform certain asset retirement activities, including requirements upon lease or easement termination to remove wireless infrastructure or remediate the land upon which its wireless infrastructure resides. Accretion expense related to liabilities for retirement obligations amounted to $10.1 million, $8.1 million, and $6.5 million for the years ended December 31, 2014, 2013, and 2012, respectively. During the year ended December 31, 2013, the Company recorded $16.3 million in asset retirement obligations as a result of the AT&T Acquisition. As of December 31, 2014 and 2013, liabilities for retirement obligations were $128.2 million and $118.4 million, respectively, representing the net present value of the estimated expected future cash outlay. As of December 31, 2014, the estimated undiscounted future cash outlay for asset retirement obligations was approximately $1.2 billion. See note 2.