FAIR VALUE MEASUREMENTS (Tables)

12 Months Ended

Dec. 31, 2014

Fair Value Disclosures [Abstract]

Assets and liabilities measured at fair value on recurring basis

Assets and liabilities measured at fair value on a recurring basis at December 31 are presented below (in thousands):

			Estimated fair value measurements
	Carrying value		Quoted prices in active markets (Level 1)		Significant other observable inputs (Level 2)		Significant unobservable inputs (Level 3)
December 31, 2014:
Assets - cash equivalents	$	314,570	$	314,570	$	—	$	—
Other assets	16,304		16,304		—		—
December 31, 2013:
Assets - cash equivalents	$	1,063,500	$	1,063,500	$	—	$	—

Fair value of financial instruments

Estimated fair values and related carrying values of our long-term debt securities at December 31 are presented below (in thousands):

	2014				2013
	Fair value		Carrying value		Fair value		Carrying value
5% Senior Notes, due 2017	$	414,552	$	399,244	$	433,879	$	398,961
7.875% Senior Notes, due 2019	570,626		498,500		603,177		498,171
4.875% Senior Notes, due 2022	680,165		711,640		711,816		713,208
4.75% Senior Notes, due 2024	377,703		399,631		—		—
5.4% Senior Notes, due 2042	345,835		398,417		368,602		398,360
5.85% Senior Notes, due 2044	366,132		399,892		—		—
	$	2,755,013	$	2,807,324	$	2,117,474	$	2,008,700