Organization and Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013 item	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Organization and Summary of Significant Accounting Policies
Number of reportable segments	1
Cash and cash equivalents	$ 10,816	$ 13,638	$ 21,089	$ 5,530
Maximum period before cash and cash equivalents are not sufficient to sustain operations	1 year
Minimum period of uncertainty regarding the entity's ability to maintain liquidity sufficient to operate business effectively	12 months