Income Taxes (Details) (USD $)	3 Months Ended						6 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2013	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Deferred tax assets:
Deferred tax assets, net operating losses											$ 36,764,901	$ 32,109,373
Deferred tax assets, capitalized research and development costs											2,950,555	3,674,469
Deferred tax assets, intangible assets											1,572,281	1,814,271
Deferred tax assets, share-based compensation cost											1,768,990	1,417,093
Deferred tax assets, property, plant and equipment											709,184	777,957
Deferred tax assets, deferred income											4,403,266	0
Deferred tax assets, other											1,104,612	896,251
Deferred tax assets, gross											49,273,789	40,689,414
Deferred tax assets, valuation allowance											(4,328,233)	(4,629,238)
Deferred tax assets, net of valuation allowance											44,945,556	36,060,176
Deferred tax liabilities:
Deferred tax liabilities, goodwill											(203,682)	(183,373)
Deferred tax liabilities, capitalized contract costs											(1,017,269)	0
Deferred tax assets, net											43,724,605	35,876,803
Operating loss carryforwards from excess tax deductions on stock option activity											700,000
Federal net operating loss carryforwards											103,800,000
Federal net operating loss carryforwards, Expired											1,200,000	900,000
Benefit from (provision for) income taxes	1,932,719	2,470,346	1,660,720	1,527,275	32,907,988	1,511,563	3,593,439	32,895,101	6,063,785	34,422,376	7,844,153	36,031,646	(175,175)
Other income, tax credit program													$ 648,000
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
U.S. federal statutory taxes											(35.00%)	(35.00%)	(34.00%)
State and local income taxes											(1.40%)	0.30%	0.00%
Loss from fair value of common warrants											(1.30%)	(123.40%)	25.80%
Share-based compensation cost											0.80%	24.80%	0.00%
Other adjustments											0.50%	1.40%	1.00%
Change in deferred tax assets valuation allowance											0.50%	(387.60%)	7.50%
Effective income tax rate											(35.90%)	(519.50%)	0.30%