Credit Facilities (Tables)

6 Months Ended

Jun. 30, 2015

Line of Credit Facility [Line Items]

Summary Of Costs Incurred Connection With Credit Facilities

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(Dollars in thousands)	2015		2014		2015		2014
Credit facility fees incurred	$	167	$	221	$	299	$	395

Wells Fargo Bank Group Credit Facility [Member]

Line of Credit Facility [Line Items]

Summary Of Outstanding Letters Of Credit And/Or Borrowings

(Dollars in thousands)		At June 30, 2015					At December 31, 2014
Bank		Commitment		In Use		Date of Expiry	Commitment		In Use		Date of Expiry
Wells Fargo Bank Group Credit Facility	Tranche One	$	200,000	$	-		$	200,000	$	-
	Tranche Two		600,000		450,100	12/31/2015		600,000		444,012	12/31/2015
Total Wells Fargo Bank Group Credit Facility		$	800,000	$	450,100		$	800,000	$	444,012

Citibank Bilateral Agreement [Member]

Line of Credit Facility [Line Items]

Summary Of Outstanding Letters Of Credit And/Or Borrowings

(Dollars in thousands)	At June 30, 2015					At December 31, 2014
Bank	Commitment		In Use		Date of Expiry	Commitment		In Use		Date of Expiry
Citibank Bilateral Letter of Credit Agreement	$	300,000	$	3,672	11/24/2015	$	300,000	$	112	8/30/2015
				68,772	12/31/2015				3,672	11/24/2015
				106	8/30/2016				70,922	12/31/2015
				2,950	12/31/2016				2,014	12/31/2016
				132,877	6/30/2019				149,353	12/31/2018
Total Citibank Bilateral Agreement	$	300,000	$	208,377		$	300,000	$	226,073