Warrants (Details) (USD $)	3 Months Ended
Mar. 31, 2013
Warrants [Abstract]
Warrants issuable under agreement with Comcast, Maximum (in shares)	975,000
Investment warrants, exercise price (in dollars per share)	$ 4.9498
Investment warrants expiration period from issuance date	3 years

Exercise price of the warrants.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column A

Name:	invest_InvestmentWarrantsExercisePrice
Namespace Prefix:	invest_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration