CONDENSED CONSOLIDATED BALANCE SHEETS ( UNAUDITED ) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current Assets:
Accounts and notes receivable (less allowances)	$ 5,344	$ 5,000
SNI shareholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	25,000,000	25,000,000
Preferred stock, outstanding (in shares)		0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Class A [Member]
SNI shareholders' equity:
Preferred stock, outstanding (in shares)	0
Common stock, authorized (in shares)	240,000,000	240,000,000
Common stock, issued (in shares)	115,461,988	122,828,359
Common stock, outstanding (in shares)	115,461,988	122,828,359
Voting Common Stock [Member]
SNI shareholders' equity:
Common stock, authorized (in shares)	60,000,000	60,000,000
Common stock, issued (in shares)	34,317,173	34,317,173
Common stock, outstanding (in shares)	34,317,173	34,317,173