Organization and Summary of Significant Accounting Policies Trade Accounts Receivable and Allowance for Doubtful Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allowance for doubtful accounts [Roll Forward]
Balance at beginning of period	$ 20	$ 43	$ 9
Adjustments to costs and expenses-offs	(18)	(16)	34
Write-offs	0	(7)	0
Balance at end of period	$ 2	$ 20	$ 43
Accounts Receivable [Member]
Concentration Risk [Line Items]
Customer concentration risk (in hundredths)	10.00%	10.00%
Minimum threshold for reporting concentration risk	10.00%	10.00%
Accounts Receivable [Member] | Comcast [Member]
Concentration Risk [Line Items]
Customer concentration risk (in hundredths)	52.00%	41.00%
Accounts Receivable [Member] | Office Max [Member]
Concentration Risk [Line Items]
Customer concentration risk (in hundredths)	10.00%	13.00%
Accounts Receivable [Member] | Staples [Member]
Concentration Risk [Line Items]
Customer concentration risk (in hundredths)		17.00%
Accounts Receivable [Member] | Office Depot [Member]
Concentration Risk [Line Items]
Customer concentration risk (in hundredths)		15.00%