Fair Value of Financial Instruments and Non-Financial Assets (Tables)

12 Months Ended

Dec. 31, 2011

Schedule of Fair Value - Assets Measured on Recurring Basis

The following tables set forth by level within the fair value hierarchy the Company's assets and liabilities that were recorded at fair value as of December 31, 2011 and December 31, 2010 (in thousands). As required by the guidance for fair value measurements, financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Thus, assets and liabilities categorized as Level 3 may be measured at fair value using inputs that are observable (Levels 1 and 2) and unobservable (Level 3). Management's assessment of the significance of a particular input to the fair value measurement requires judgment, which may affect the valuation of assets and liabilities and their placement within the fair value hierarchy levels.



	At Fair Value as of December 31, 2011
	Level 1		Level 2		Level 3		Total

Assets:
Money market funds	$	—	$	224,383	$	—	$	224,383
Commercial paper	—		165,202		—		165,202
U.S. government or government agency securities	—		293,610		—		293,610
Total	$	—	$	683,195	$	—	$	683,195



	At Fair Value as of December 31, 2010
	Level 1		Level 2		Level 3		Total

Assets:
Money market funds	$	—	$	168,831	$	—	$	168,831
Commercial paper	—		17,494		—		17,494
U.S. government or government agency securities	—		108,364		—		108,364
Total	$	—	$	294,689	$	—	$	294,689

Summary of Changes in Fair Value of Company's Level 3 Assets

The following table provides a summary of the changes in the fair value of the Company's Level 3 financial assets (in thousands).



	Year Ended December 31,
	2011		2010
Beginning balance, January 1	$	—	$	2,731
Total gains (losses):
Included in net loss	$	—	$	3,341
Included in comprehensive income (loss)	—		(1,680		)
Purchases and (sales):
Sales	—		(4,392		)
Transfers in (out) of Level 3	—		—
Ending balance, December 31,	$	—	$	—

Available-for-sale Securities

Available-for-sale securities were comprised as follows as of December 31, 2011 and December 31, 2010 (in thousands):



	As of December 31, 2011
	Cost		Fair Value

Money market funds	$	224,383	$	224,383
Commercial paper	165,201		165,202
U.S. government or government agency securities	293,626		293,610
	$	683,210	$	683,195



	As of December 31, 2010
	Cost		Fair Value

Money market funds	$	168,831	$	168,831
Commercial paper	17,494		17,494
U.S. government or government agency securities	108,364		108,364
	$	294,689	$	294,689

Schedule of Fair Value - Assets Measured on a Nonrecurring Basis

The tables below summarize the non-financial assets that were measured and recorded at fair value on a non-recurring basis as of December 31, 2011 and December 31, 2010 and the losses recorded during the years ended December 31, 2011 and 2010 on those assets (in thousands):



	At Fair Value as of December 31, 2011
	Level 1		Level 2		Level 3		Losses

Assets:
Wireless licenses	$	—	$	—	$	9,115	$	377
Total	$	—	$	—	$	9,115	$	377



	At Fair Value as of December 31, 2010
	Level 1		Level 2		Level 3		Losses

Assets:
Goodwill	$	—	$	—	$	—	$	430,101
Property and equipment	—		—		—		46,460
Wireless licenses	—		—		7,496		766
Total	$	—	$	—	$	7,496	$	477,327

- Definition

Tabular disclosure of available-for-sale securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

Tabular disclosure of assets and liabilities by class, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a nonrecurring basis in periods after initial recognition (for example, impaired assets). The disclosures that may be required or desired include: (a) the fair value measurements recorded during the period and the reasons for the measurements and (b) the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets or liabilities (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). Where the quoted price in an active market for the identical liability is not available, the Level 1 input is the quoted price of an identical liability when traded as an asset.

+ References+ Details

- Definition

Tabular disclosure of the fair value measurement of assets using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income, and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issuances, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset.

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