Summary of Significant Accounting Policies (Details) (USD $)	0 Months Ended	12 Months Ended		9 Months Ended
	Dec. 14, 2011	Dec. 31, 2012 item	Dec. 31, 2011	Sep. 30, 2012 Supernus Executive Retirement Plan (SERP) item	Dec. 31, 2012 Supernus Executive Retirement Plan (SERP)	Dec. 31, 2011 Supernus Executive Retirement Plan (SERP)	Dec. 31, 2012 Quoted Prices in Active Markets (Level 1)	Dec. 31, 2011 Quoted Prices in Active Markets (Level 1)	Dec. 31, 2012 Significant Other Observable Inputs (Level 2)	Dec. 31, 2011 Significant Other Observable Inputs (Level 2)	Dec. 31, 2012 Significant Unobservable Inputs (Level 3)	Dec. 31, 2011 Significant Unobservable Inputs (Level 3)	Dec. 31, 2012 Total Carrying Value	Dec. 31, 2011 Total Carrying Value
Basis of Presentation
Equity interest sold (as a percent)	100.00%
Number of business segments		1
Accrued compensation reclassified to accounts payable and accrued expenses			$ 1,500,000
Interest payable reclassified to accounts payable and accrued expenses			100,000
Reverse Stock Split
Conversion ratio of reverse stock split		0.25
Fair value of financial instruments
Number of executives for whom SERP was established				2
Assets:
Cash and cash equivalents							31,561,000	48,544,000	8,741,000				40,302,000	48,544,000
Marketable securities		48,206,000							48,206,000				48,206,000
Marketable securities - restricted		279,000	245,000		279,000	245,000			279,000	245,000			279,000	245,000
Total assets at fair value							31,561,000	48,544,000	57,226,000	245,000			88,787,000	48,789,000
Liabilities:
Warrant liability		$ 251,000	$ 697,000								$ 251,000	$ 697,000	$ 251,000	$ 697,000