Fair Value Measurements (Table)

6 Months Ended

Jun. 30, 2014

Fair Value Disclosures

Fair value measurements

		Level within the Fair Value Hierarchy	June 30, 2014				December 31, 2013
			Book Value			Fair Value	Book Value		Fair Value
(Dollars in thousands)
Cash and cash equivalents		1	$	404,058	$	404,058	$	342,065	$	342,065
Short-term investments
	U.S. Treasury Notes	1		40,035		40,035		50,104		50,104
Long-term debt
	6.95% Senior Notes	1		342,000		348,703		342,000		309,852
	6.7% Senior Notes	2		532,583		550,727		532,449		507,697