COMMON STOCK: (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended													12 Months Ended										12 Months Ended
	Feb. 28, 2013	Dec. 31, 2012	Nov. 29, 2012	Sep. 30, 2012	Aug. 31, 2012	Jun. 30, 2012	May 31, 2012	Mar. 31, 2012	Feb. 29, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 9.25% Senior Secured Second Lien Notes, due 2017	Oct. 29, 2009 9.25% Senior Secured Second Lien Notes, due 2017	Dec. 31, 2012 8.375% Senior Notes, due 2018	Oct. 04, 2010 8.375% Senior Notes, due 2018	Dec. 31, 2012 6.125% Notes	Oct. 12, 2012 6.125% Notes	Dec. 31, 2012 Bank Credit Agreement	Dec. 31, 2012 Class A Common Stock item	Dec. 31, 2012 Class B Common Stock item	Dec. 31, 2011 Class B Common Stock
Common Stock
Number of votes holders of common stock are entitled for each share held																								1	10
Number of Class B shares converted into Class A Common stock																										1,149,960
Interest rate (as a percent)																	9.25%	9.25%	8.375%	8.375%	6.125%	6.125%
Quarterly dividend declared (in dollars per share)	$ 0.15		$ 0.15		$ 0.15		$ 0.12		$ 0.12					$ 1.54	$ 0.48	$ 0.43
Dividend paid (in dollars per share)		$ 0.15		$ 0.15		$ 0.12		$ 0.12		$ 0.12	$ 0.12	$ 0.12	$ 0.12		$ 0.48
Special cash dividend declared (in dollars per share)			$ 1.00
Special cash dividend paid (in dollars per share)		$ 1.00												$ 1.54
Amount of unrestricted annual cash payments																							$ 100.0
Amount of unrestricted annual cash payments to be carry over to next year																							$ 50.0