Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2013

Marketable Securities

Schedule of amortized cost and fair value for held-to-maturity securities by major security type

	March 31, 2013
	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value
Certificates of deposit	$	2,557,996	$	5,499	$	—	$	2,563,495
Municipal bonds	944,414		3,279		—		947,693
	$	3,502,410	$	8,778	$	—	$	3,511,188

	December 31, 2012
	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Fair Value
Certificates of deposit	$	2,802,993	$	8,684	$	—		$	2,811,677
Municipal bonds	2,903,003		5,057		(30		)	2,908,030
	$	5,705,996	$	13,741	$	(30	)	$	5,719,707