Cash, Cash Equivalents, and Investments (Tables)

3 Months Ended

Mar. 31, 2013

Cash, Cash Equivalents and Investments [Abstract]

Summary of cash, cash equivalents and held-to-maturity investments by type

	March 31, 2013								December 31, 2012
	Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value		Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Cash and money market funds	$	38,580,384	$	—	$	—	$	38,580,384	$	36,126,791	$	—	$	—		$	36,126,791
Corporate bonds		—		—		—		—		958		—		—			958
Certificates of deposit		—		—		—		—		1,680,000		—		(1,488	)		1,678,512
Total cash, cash equivalents and investments	$	38,580,384	$	—	$	—	$	38,580,384	$	37,807,749	$	—	$	(1,488	)	$	37,806,261

Summarized classification of short term and Long term investments

	March 31, 2013		December 31, 2012
Cash	$	38,580,384	$	19,811,735
Cash equivalents		—		16,315,056
Total cash and cash equivalents		38,580,384		36,126,791
Short-term investments		—		1,680,958
Total cash, cash equivalents and investments	$	38,580,384	$	37,807,749