Warrants (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Revenue, Major Customer [Line Items]
Warrant-related charges	$ 383,000	$ 0
Comcast [Member]
Revenue, Major Customer [Line Items]
Warrants issuable, maximum (in shares)	975,000	975,000
Warrants, exercise price (in dollars per share)	$ 4.9498	$ 4.9498
Investment warrants expiration period from issuance date	3 years	3 years
Warrants issued (in shares)	166,000	0
Warrant-related charges	383,000	0
Comcast [Member] | First Tranche [Member]
Revenue, Major Customer [Line Items]
Warrants issuable, maximum (in shares)	166,000
Warrants issued (in shares)	166,000
Warrant-related charges	383,000
Fair value assumptions for warrants issued [Abstract]
Risk free interest rate (in hundredths)	0.64%
Expected term	3 years
Volatility (in hundredths)	58.51%
Expected dividend (in hundredths)	0.00%
Comcast [Member] | Second Tranche [Member]
Revenue, Major Customer [Line Items]
Warrants issuable, maximum (in shares)	324,000
Warrants issued (in shares)	0
Warrant-related charges	0
Comcast [Member] | Third Tranche [Member]
Revenue, Major Customer [Line Items]
Warrants issuable, maximum (in shares)	485,000
Warrants issued (in shares)	0
Warrant-related charges	$ 0