COMMON STOCK (Details)		1 Months Ended									12 Months Ended
	May. 07, 2013 USD ($) $ / shares shares	Feb. 29, 2016 $ / shares	Nov. 30, 2015 $ / shares	Aug. 31, 2015 $ / shares	Apr. 30, 2015 $ / shares	Feb. 28, 2015 $ / shares	Nov. 30, 2014 $ / shares	Aug. 31, 2014 $ / shares	Apr. 30, 2014 $ / shares	Feb. 28, 2014 $ / shares	Dec. 31, 2015 USD ($) vote $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) $ / shares	Mar. 20, 2014 USD ($)	Oct. 12, 2013	Oct. 11, 2013	Apr. 02, 2013	Oct. 12, 2012	Oct. 28, 1999 USD ($)
Common Stock
Net proceeds from public offering											$ 0	$ 0	$ 472,913,000
Quarterly dividend declared (in dollars per share) | $ / shares			$ 0.165	$ 0.165	$ 0.165	$ 0.165	$ 0.165	$ 0.165	$ 0.15	$ 0.15	$ 0.66	$ 0.63	$ 0.6
Share repurchase program, authorized amount														$ 150,000,000.0					$ 150,000,000.0
Dividend paid (in dollars per share) | $ / shares												$ 0.63
Number of shares repurchased | shares											1,100,000
Value of shares repurchased											$ 28,800,000	$ 133,157,000
Total remaining authorization amount											$ 105,500,000.0
Bank Credit Agreement
Common Stock
Unrestricted Cash First Lien Indebtedness Ratio											4.00
Amount of unrestricted annual cash payments (up to)											$ 200,000,000.0
Amount of unrestricted annual cash payments to be carry over to next year											50,000,000
Additional aggregate basket (up to)											250,000,000.0
Aggregate basket as long as no Event											$ 50,000,000
Bank Credit Agreement | Maximum
Common Stock
Unrestricted Cash First Lien Indebtedness Ratio											3.75
6.125% Senior Unsecured Notes, due 2022
Common Stock
Interest rate (as a percent)											6.125%	6.125%			6.125%			6.125%
5.375% Senior Unsecured Notes, due 2021
Common Stock
Interest rate (as a percent)											5.375%	5.375%					5.375%
6.375% Senior Notes, due 2021
Common Stock
Interest rate (as a percent)											6.375%	6.375%				6.375%
5.625% Senior Notes, due
Common Stock
Interest rate (as a percent)												5.625%
Subsequent Event
Common Stock
Quarterly dividend declared (in dollars per share) | $ / shares		$ 0.165
Class A Common Stock
Common Stock
Number of votes holders of common stock are entitled for each share held | vote											1
Shares sold public offering (in shares) | shares	18,000,000
Offering price (in dollars per share) | $ / shares	$ 27.25
Net proceeds from public offering	$ 472,900,000
Class B Common Stock
Common Stock
Number of votes holders of common stock are entitled for each share held | vote											10
Number of Class B shares converted into Class A Common stock | shares											0	100,000