CREDIT FACILITIES, SHORT-TERM LOAN FACILITY AND LONG-TERM DEBT (Details) (USD $)	12 Months Ended	0 Months Ended	3 Months Ended	12 Months Ended		0 Months Ended
	Dec. 31, 2014	Oct. 01, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 02, 2013	Jul. 01, 2013	Dec. 31, 2014
Credit facilities, short-term loan facility and long-term debt
Credit facilities, short-term loan facility and long-term debt	$ 1,695,000,000		1,695,000,000	1,578,000,000				1,695,000,000
Less: current portion	249,000,000		249,000,000	3,000,000				249,000,000
Long-term debt	1,446,000,000		1,446,000,000	1,575,000,000				1,446,000,000
Borrowings under facility	170,000,000
Term loan
Credit facilities, short-term loan facility and long-term debt
Credit facilities, short-term loan facility and long-term debt	170,000,000		170,000,000					170,000,000
Amount of facility		170,000,000
Borrowings under facility		170,000,000
Term of the facility		364 days
Term loan | LIBOR
Credit facilities, short-term loan facility and long-term debt
Variable rate basis		one-month LIBOR
Basis spread on variable rate (as a percent)		1.00%
Debt average interest rate (as a percent)			1.28%
Debt interest rate, at period end (as a percent)	1.28%		1.28%					1.28%
Term loan | Prime rate
Credit facilities, short-term loan facility and long-term debt
Variable rate basis		prime rate
Term loan | Federal funds rate
Credit facilities, short-term loan facility and long-term debt
Variable rate basis		federal funds rate
Basis spread on variable rate (as a percent)		0.50%
Senior Credit Facility due 2017
Credit facilities, short-term loan facility and long-term debt
Credit facilities, short-term loan facility and long-term debt	330,000,000		330,000,000	380,000,000				330,000,000
Senior Credit Facility due 2017 | Maximum
Credit facilities, short-term loan facility and long-term debt
Option to increase credit facility borrowing capacity	250,000,000		250,000,000					250,000,000
Senior Credit Facility due 2017 | LIBOR
Credit facilities, short-term loan facility and long-term debt
Variable rate basis	LIBOR			LIBOR	LIBOR
Debt average interest rate (as a percent)	1.41%			1.44%	1.61%
Debt interest rate, at period end (as a percent)	1.41%		1.41%	1.42%				1.41%
Senior Credit Facility due 2017 | Senior revolving credit facility
Credit facilities, short-term loan facility and long-term debt
Maximum borrowing capacity	500,000,000		500,000,000					500,000,000
Amount outstanding under credit facility	330,000,000		330,000,000	380,000,000				330,000,000
Remaining borrowing capacity	170,000,000		170,000,000					170,000,000
Term Loan Facility due 2018
Credit facilities, short-term loan facility and long-term debt
Credit facilities, short-term loan facility and long-term debt	500,000,000		500,000,000	500,000,000				500,000,000
Maximum borrowing capacity							500,000,000
Borrowings under the facility						500,000,000
Term Loan Facility due 2018 | LIBOR borrowings | LIBOR
Credit facilities, short-term loan facility and long-term debt
Variable rate basis	LIBOR			LIBOR			LIBOR
Debt average interest rate (as a percent)	1.41%			1.43%
Debt interest rate, at period end (as a percent)	1.41%		1.41%	1.42%				1.41%
Term Loan Facility due 2018 | LIBOR borrowings | LIBOR | Minimum
Credit facilities, short-term loan facility and long-term debt
Basis spread on variable rate (as a percent)							1.125%
Term Loan Facility due 2018 | LIBOR borrowings | LIBOR | Maximum
Credit facilities, short-term loan facility and long-term debt
Basis spread on variable rate (as a percent)							2.00%
Term Loan Facility due 2018 | LIBOR borrowings | LIBOR | Hedges of cash flows | Interest rate swaps
Credit facilities, short-term loan facility and long-term debt
Debt average interest rate (as a percent)	1.82%			1.70%
Term Loan Facility due 2018 | Base rate borrowings | LIBOR
Credit facilities, short-term loan facility and long-term debt
Variable rate basis							one-month LIBOR
Basis spread on variable rate (as a percent)							1.00%
Term Loan Facility due 2018 | Base rate borrowings | Base rate
Credit facilities, short-term loan facility and long-term debt
Variable rate basis							Lender prime rate, federal funds rate or one-month LIBOR
Term Loan Facility due 2018 | Base rate borrowings | Base rate | Minimum
Credit facilities, short-term loan facility and long-term debt
Basis spread on variable rate (as a percent)							0.125%
Term Loan Facility due 2018 | Base rate borrowings | Base rate | Maximum
Credit facilities, short-term loan facility and long-term debt
Basis spread on variable rate (as a percent)							1.00%
Term Loan Facility due 2018 | Base rate borrowings | Prime rate
Credit facilities, short-term loan facility and long-term debt
Variable rate basis							prime rate
Term Loan Facility due 2018 | Base rate borrowings | Federal funds rate
Credit facilities, short-term loan facility and long-term debt
Variable rate basis							federal funds rate
Basis spread on variable rate (as a percent)							0.50%
Senior Credit Facility, Term Loan Facilities and Short-Term Loan Facility
Credit facilities, short-term loan facility and long-term debt
Leverage ratio (as a percent)								436.00%
Senior Credit Facility, Term Loan Facilities and Short-Term Loan Facility | Debt agreement covenants, period prior to occurrence of specified material acquisition | Maximum
Credit facilities, short-term loan facility and long-term debt
Leverage ratio (as a percent)	500.00%
Senior Credit Facility, Term Loan Facilities and Short-Term Loan Facility | Debt agreement covenants, initial period after occurrence of specified material acquisition
Credit facilities, short-term loan facility and long-term debt
Additional period immediately following the fiscal quarter in which a specified material acquisition occurs	6 months
Senior Credit Facility, Term Loan Facilities and Short-Term Loan Facility | Debt agreement covenants, initial period after occurrence of specified material acquisition | Maximum
Credit facilities, short-term loan facility and long-term debt
Leverage ratio (as a percent)	550.00%
Senior Credit Facility, Term Loan Facilities and Short-Term Loan Facility | Debt agreement covenants, periods subsequent to initial period after occurrence of specified material acquisition | Maximum
Credit facilities, short-term loan facility and long-term debt
Leverage ratio (as a percent)	500.00%
4.65% Senior Notes due 2021
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	4.65%		4.65%	4.65%				4.65%
Credit facilities, short-term loan facility and long-term debt	350,000,000		350,000,000	349,000,000				350,000,000
5.09% Unsecured Senior Notes due 2015
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	5.09%		5.09%	5.09%				5.09%
Credit facilities, short-term loan facility and long-term debt	75,000,000		75,000,000	75,000,000				75,000,000
5.29% Unsecured Senior Notes due 2020
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	5.29%		5.29%	5.29%				5.29%
Credit facilities, short-term loan facility and long-term debt	100,000,000		100,000,000	100,000,000				100,000,000
5.69% Unsecured Senior Notes due 2035
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	5.69%		5.69%	5.69%				5.69%
Credit facilities, short-term loan facility and long-term debt	150,000,000		150,000,000	150,000,000				150,000,000
3.82% Series D Senior Notes due 2017
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	3.82%		3.82%	3.82%				3.82%
Credit facilities, short-term loan facility and long-term debt	$ 20,000,000		20,000,000	24,000,000				20,000,000
GTN | 5.09% Unsecured Senior Notes due 2015
Credit facilities, short-term loan facility and long-term debt
Stated interest rate (as a percent)	5.09%		5.09%					5.09%
GTN | Senior Notes | Maximum
Credit facilities, short-term loan facility and long-term debt
Percentage of debt to total capitalization	70.00%