FAIR VALUE MEASUREMENTS

6 Months Ended

Jun. 30, 2012

FAIR VALUE MEASUREMENTS

2. FAIR VALUE MEASUREMENTS

Items Measured at Fair Value on a Recurring Basis – The Company’s earnouts related to acquisitions are measured at fair value on a recurring basis using Level 3 inputs. The Company determines the fair value of acquisition-related contingent consideration, and any subsequent changes in fair value, using a discounted probability-weighted approach, as determined using Level 3 inputs. The fair value of the earnouts is reviewed quarterly and is based on the payments the Company expects to make based on historical internal observations related to the anticipated performance of the underlying assets. The Company’s estimate of the fair value of its obligation if the performance targets contained in various acquisition agreements were met was $2.5 million and $5.5 million as of June 30, 2012 and December 31, 2011, respectively, which the Company recorded in accrued expenses on its Consolidated Balance Sheet. The maximum potential obligation related to the performance targets was $5.6 million as of June 30, 2012.

Items Measured at Fair Value on a Nonrecurring Basis – The Company’s intangibles, certain long-lived assets, and asset retirement obligations are measured at fair value on a nonrecurring basis using Level 3 inputs. Level 3 valuations rely on unobservable inputs for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. The Company considers many factors and makes certain assumptions when making this assessment, including but not limited to: general market and economic conditions, historical operating results, geographic location, lease-up potential and expected timing of lease-up. The fair value of the long-lived assets, intangibles and asset retirement obligations is calculated using a discounted cash flow model. During the three and six months ended June 30, 2012, the Company recognized an impairment charge of $0.6 million and $1.0 million, respectively, related to its long-lived assets resulting from the Company’s analysis that the future cash flows from certain tower sites would not recover the carrying value of the investment in those tower sites. During the three and six months ended June 30, 2011, the Company recognized an impairment charge of $0.3 million related to its long-lived assets resulting from the Company’s analysis that the future cash flows from certain tower sites would not recover the carrying value of the investment in those tower sites.

Fair Value of Financial Instruments – The carrying values of cash and cash equivalents, accounts receivable, restricted cash, accounts payable, and short-term investments, which consist of $4.8 million and $5.6 million in certificate of deposits, as of June 30, 2012 and December 31, 2011, respectively, approximate their related estimated fair values due to the short maturity of those instruments. The Company’s estimate of the fair value of its held-to-maturity investments in treasury and corporate bonds, including current portion, are based primarily upon Level 1 reported market values. As of each of the dates ending June 30, 2012 and December 31, 2011, the carrying value and fair value of the held-to-maturity investments, including current portion, was $1.4 million and $1.6 million, respectively.

The Company determines fair value of its debt instruments utilizing various Level 2 sources including quoted prices and indicative quotes (non-binding quotes) from brokers that require judgment to interpret market information including implied credit spreads for similar borrowings on recent trades or bid/ask prices. The fair value of the Revolving Credit Facility and the Mobilitie Bridge Loan is considered to be equal to the carrying value because the interest payments are based on Eurodollar rates and LIBOR rates, respectively, that reset every month. The Company does not believe its credit risk has changed materially from the date the applicable Eurodollar Rate plus 187.5 basis points was set for the Revolving Credit Facility and the applicable LIBOR rate plus 350 basis points was set for the Mobilitie Bridge Loan. The following table reflects fair values, principal values and carrying values of the Company’s debt instruments (see Note 9).

	As of June 30, 2012						As of December 31, 2011
	Fair Value		Principal Value		Carrying Value		Fair Value		Principal Value		Carrying Value
	(in millions)
1.875% Convertible Senior Notes due 2013	$	742.6	$	535.0	$	503.0	$	605.2	$	535.0	$	485.0
4.0% Convertible Senior Notes due 2014	$	966.3	$	500.0	$	413.6	$	761.6	$	500.0	$	397.6
8.0% Senior Notes due 2016	$	259.3	$	243.8	$	242.7	$	405.0	$	375.0	$	373.2
8.25% Senior Notes due 2019	$	266.9	$	243.8	$	242.1	$	407.8	$	375.0	$	372.4
4.254% 2010-1C Tower Securities	$	710.4	$	680.0	$	680.0	$	699.0	$	680.0	$	680.0
5.101% 2010-2C Tower Securities	$	601.5	$	550.0	$	550.0	$	579.0	$	550.0	$	550.0
Revolving Credit Facility	$	284.0	$	284.0	$	284.0	$	—	$	—	$	—
2011 Term Loan	$	488.8	$	495.0	$	493.9	$	494.4	$	497.5	$	496.3
2012 Term Loan	$	197.5	$	200.0	$	200.0	$	—	$	—	$	—
Mobilitie Bridge Loan	$	400.0	$	400.0	$	400.0	$	—	$	—	$	—