Derivatives (Tables)

12 Months Ended

Dec. 31, 2014

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Derivative Instruments

The following table provides a detail of the swaps outstanding and the related hedged items as of December 31, 2014:

		Face value of	Aggregate notional amount of interest		Weighted-average variable interest rate on hedged debt as of December 31,
Issuance date	Maturity date	medium-term notes	rate swaps	Fixed interest rate	2014	2013
		(Dollars in thousands)
February 2011	March 2015	$350,000	$150,000	3.15%	1.28%	1.34%
May 2011	June 2017	$350,000	$150,000	3.50%	1.42%	1.44%
November 2013	November 2018	$300,000	$100,000	2.45%	1.19%	1.19%
February 2014	June 2019	$350,000	$100,000	2.55%	1.10%	—%
May 2014	September 2019	$400,000	$100,000	2.45%	0.86%	—%

Impact on the Consolidated Condensed Statements of Earnings related to Fair Value Hedges

The location and amount of (gains) losses on derivative instruments and related hedged items reported in the Consolidated Statements of Earnings were as follows:

	Location of (Gain) Loss Recognized in Income	December 31,
Fair Value Hedging Relationship		2014			2013		2012
		(In thousands)
Derivative: Interest rate swap	Interest expense	$	(3,341	)	(8,554	)	(5,118	)
Hedged item: Fixed-rate debt	Interest expense	3,341			8,554		5,118
Total		$	—		—		—