Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2015

Investments, All Other Investments [Abstract]

Summary of Carrying Amounts and Estimated Fair Values of Other Financial Instruments

The following table summarizes the carrying amounts and estimated fair values of our other financial instruments at June 30, 2015:

	Carrying Amount		Fair Value
	(Dollars in thousands)
Assets:
Cash and cash equivalents	$	126,676	$	126,676
Liabilities:
Bank debt	$	1,184,089	$	1,184,089
5½% Senior Notes	300,000		311,436
5% Senior Notes	500,000		511,250
Interest rate swap agreements	1,280		1,280
Natural gas swap agreements	367		367