Summary of Significant Accounting Policies - Out of Period Adjustments (Details) (Immaterial Corrections [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Sep. 30, 2011	Mar. 31, 2011
Effect of Fourth Quarter Events [Line Items]
Effect of Fourth Quarter Events, Decrease in Revenue, Amount	$ (87)			$ 88
Effect of Fourth Quarter Events, Decrease Allocated Share Based Compensation Expense Amount, Cumulative Prior Years 2010 and 2011	65
Effect of Fourth Quarter Events, Decrease Allocated Share Based Compensation Expense Amount	106	32
Effect of Fourth Quarter Events, Increase Royalty Expense Amount	39		20
Year Ended December 31, 2011 [Member]
Effect of Fourth Quarter Events [Line Items]
Effect of Fourth Quarter Events, Decrease Allocated Share Based Compensation Expense Amount	35
Year Ended December 31, 2010 [Member]
Effect of Fourth Quarter Events [Line Items]
Effect of Fourth Quarter Events, Decrease Allocated Share Based Compensation Expense Amount	$ 30