Fair Value Measurements

9 Months Ended

Sep. 30, 2011

Fair Value Measurements [Abstract]

Fair Value Measurements

Note 6. Fair Value Measurements

FASB ASC 820 — Fair Value Measurements and Disclosures, defines fair value as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. FASB ASC 820 requires disclosures about the fair value of all financial instruments, whether or not recognized, for financial statement purposes. Disclosures about the fair value of financial instruments are based on pertinent information available to us as of the reporting dates. Accordingly, the estimates presented in these condensed consolidated financial statements are not necessarily indicative of the amounts that could be realized on disposition of the financial instruments.

FASB ASC 820 specifies a hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect market assumptions. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement).

The three levels of the fair value hierarchy are as follows:

Level 1 — Quoted prices for identical instruments in active markets.

Level 2 — Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable.

Level 3 — Instruments with primarily unobservable value drivers.

The following table represents the fair value of our financial assets and financial liabilities measured at fair value on a recurring basis and which level was used in the fair value hierarchy.

At September 30, 2011
	Carrying			Fair		Fair Value Measurements at the Reporting Date Using
	Value			Value		Level 1		Level 2		Level 3
Assets
Short-term investments	$	90,291,868		$	90,291,868	$	—	$	90,291,868	$	—
Foreign exchange instrument		101,250			101,250		—		101,250		—
Liabilities
Convertible senior notes		92,876,969	(1)		141,899,938		—		141,899,938		—

At December 31, 2010
	Carrying			Fair		Fair Value Measurements at the Reporting Date Using
	Value			Value		Level 1		Level 2		Level 3
Assets
Short-term investments	$	21,330,110		$	21,330,110	$	—		21,330,110	$	—
Long-term investments		4,005,659			4,005,659		—		4,005,659		—
Liabilities
Convertible senior notes		88,921,557	(1)		160,693,813		—		160,693,813		—

(1) The carrying amount of our convertible senior notes is net of unamortized discount. See Note 11, “Debt” for more information.

The fair value of our investments was determined using quoted prices for the instruments in markets that are not considered active. The fair value of our foreign exchange instrument was determined using observable market data such as pricing for similar instruments or recently executed transactions. The fair value of our convertible senior notes was determined using observable market data (including trade data) and is presented for disclosure purposes only.