Debt and Financing Arrangements (Tables)

12 Months Ended

Dec. 31, 2013

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments [Table Text Block]

The following table shows the Company’s financing structure:

	Outstanding(1)		Balance(2)
December 31, 2013
2006 Senior notes due 2016	$	500,000	$	499,512
2010 Senior notes due 2020	300,000		298,987
$1,000,000 Secured letter of credit facility — uncommitted	707,915		—
$450,000 Secured letter of credit facility — committed	86,102		—
	$	1,594,017	$	798,499
December 31, 2012
2006 Senior notes due 2016	$	500,000	$	499,347
2010 Senior notes due 2020	300,000		298,868
$1,000,000 Secured letter of credit facility — uncommitted	907,592		—
$450,000 Secured letter of credit facility — committed	108,853		—
	$	1,816,445	$	798,215

(1) Indicates utilization of commitment amount, not drawn borrowings.

(2) Represents the principal amount borrowed, net of unamortized discount.

Schedule of Maturities of Long-term Debt [Table Text Block]

The following table reflects the Company’s debt maturities:

	Amount
2014	$	—
2015	—
2016	500,000
2017	—
2018	—
2019 and thereafter	300,000
Total	$	800,000