Credit Facilities (Tables)

12 Months Ended

Dec. 31, 2014

Line of Credit Facility [Line Items]

Summary Of Costs Incurred Connection With Credit Facilities

	Years Ended December 31,
(Dollars in thousands)	2014		2013		2012
Credit facility fees incurred	$	659	$	964	$	3,519

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 December 31, 2014					At December 31, 2013
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		444,012	12/31/2015		600,000		502,059	12/31/2014
Total Wells Fargo Bank Group Credit Facility		$	800,000	$	444,012		$	800,000	$	502,059

Citibank Bilateral Agreement [Member]

Line of Credit Facility [Line Items]

Summary Of Outstanding Letters Of Credit And/Or Borrowings

(Dollars in thousands)	At December 31, 2014					At December 31, 2013
Bank	Commitment		In Use		Date of Expiry	Commitment		In Use		Date of Expiry
Citibank Bilateral Letter of Credit Agreement	$	300,000	$	112	8/30/2015	$	300,000	$	119	8/30/2014
				3,672	11/24/2015				3,672	11/24/2014
				70,922	12/31/2015				79,336	12/31/2014
				2,014	12/31/2016				1,045	12/31/2015
				149,353	12/30/2018				22,800	12/31/2017
				-					129,147	3/30/2018
Total Citibank Bilateral Agreement	$	300,000	$	226,073		$	300,000	$	236,119

Citibank Holdings Credit Facility [Member]

Line of Credit Facility [Line Items]

Summary Of Outstanding Letters Of Credit And/Or Borrowings

(Dollars in thousands)	At December 31, 2014						At December 31, 2013
Bank	Commitment		In Use		Date of Loan	Maturity/Expiry Date	Commitment		In Use		Date of Loan	Maturity/Expiry Date
Citibank Holdings Credit Facility	$	-	$	-			$	150,000	$	-
Total revolving credit borrowings				-						-
Total letters of credit				-						851		12/31/2014
Total Citibank Holdings Credit Facility	$	-	$	-			$	150,000	$	851