Debt (Tables)

6 Months Ended

Jun. 30, 2014

Debt Disclosure [Abstract]

Schedule of Senior Notes

Our senior notes are summarized as follows ($000’s omitted):

	June 30, 2014		December 31, 2013
5.20% unsecured senior notes due February 2015 (a)	$	—	$	95,633
5.25% unsecured senior notes due June 2015 (a)	234,769		233,085
6.50% unsecured senior notes due May 2016 (a)	460,795		459,581
7.625% unsecured senior notes due October 2017 (b)	122,707		122,663
7.875% unsecured senior notes due June 2032 (a)	299,217		299,196
6.375% unsecured senior notes due May 2033 (a)	398,604		398,567
6.00% unsecured senior notes due February 2035 (a)	299,456		299,443
7.375% unsecured senior notes due June 2046 (a)	—		150,000
Total senior notes – carrying value (c)	$	1,815,548	$	2,058,168
Estimated fair value	$	1,910,989	$	2,070,744

(a) Redeemable prior to maturity; guaranteed on a senior basis by certain wholly-owned subsidiaries.

(b) Not redeemable prior to maturity; guaranteed on a senior basis by certain wholly-owned subsidiaries.

(c) The recorded carrying value reflects the impact of various discounts and premiums that are amortized to interest cost over the respective terms of the senior notes