Selling Arrangement (Details) (News America Settlement Agreement [Member], USD $)	1 Months Ended	3 Months Ended
	Feb. 28, 2011	Mar. 31, 2013	Mar. 31, 2012
News America Settlement Agreement [Member]
Gain Contingencies [Line Items]
Settlement agreement, amount paid	$ 4,000,000
Settlement agreement, term	10 years
Settlement agreement, amortization expense		100,000	100,000
Settlement agreement, expected yearly amortization expense, year one		400,000
Settlement agreement, expected yearly amortization expense, year two		400,000
Settlement agreement, expected yearly amortization expense, year three		400,000
Settlement agreement, expected yearly amortization expense, year four		400,000
Settlement agreement, expected yearly amortization expense, year five		$ 400,000
Settlement agreement, expected yearly amortization expense, term		5 years