Consolidated Statements of Comprehensive (Loss) Income (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement Of Income And Comprehensive Income [Abstract]
Income tax on unrealized holding during the period	$ (638,094)	$ 3,494,545	$ (13,782,319)	$ 5,895,784
Income tax on reclassification adjustment for gains	$ 118,715	$ 446,127	$ 1,000,861	$ 1,751,153