
					Weighted-
					Average Interest
		December 31,		June 30,	Rate at
		2011		2012	June 30, 2012 (a)
Revolving credit facility	$	—	$	—	—	%
$250.0 million of 6.45% Notes due 2014		249,844		249,874	6.3	%
$250.0 million of 5.65% Notes due 2016		252,037		251,823	5.6	%
$250.0 million of 6.40% Notes due 2018		263,477		262,445	5.3	%
$550.0 million of 6.55% Notes due 2019		578,521		576,804	5.6	%
$550.0 million of 4.25% Notes due 2021		558,932		558,514	4.0	%
$250.0 million of 6.40% Notes due 2037		248,964		248,972	6.4	%
Total debt	$	2,151,775	$	2,148,432	5.3	%

(a) Weighted-average interest rate includes the impact of interest rate swaps, the amortization/accretion of discounts and premiums and the amortization/accretion of gains and losses realized on historical cash flow and fair value hedges on interest expense (see Note 7—Derivative Financial Instruments for detailed information regarding fair value hedges and interest rate swaps).