
	June 30, 2011		December 31, 2010
8.125% unsecured senior notes due February 2011 (a)	$	—	$	13,900
5.45% unsecured senior notes due August 2012 (b)		97,116		104,823
6.25% unsecured senior notes due February 2013 (b)		62,647		62,617
5.125% unsecured senior notes due October 2013 (b)		116,545		160,212
5.25% unsecured senior notes due January 2014 (b)		335,859		335,848
5.70% unsecured senior notes due May 2014 (b)		310,474		309,048
5.20% unsecured senior notes due January 2015 (b)		244,862		244,839
5.25% unsecured senior notes due June 2015 (b)		400,702		397,700
6.50% unsecured senior notes due May 2016 (b)		467,894		466,644
7.625% unsecured senior notes due September 2017 (a)		149,319		149,265
7.875% unsecured senior notes due May 2032 (b)		299,087		299,065
6.375% unsecured senior notes due May 2033 (b)		398,381		398,344
6.00% unsecured senior notes due January 2035 (b)		299,377		299,363
7.375% unsecured senior notes due June 2046 (b)		150,000		150,000

Total senior notes - carrying value (c)	$	3,332,263	$	3,391,668

Estimated fair value	$	3,244,674	$	3,227,404

(a)

Not redeemable prior to maturity, guaranteed on a senior basis by certain wholly-owned subsidiaries

(b)

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