Debt

Debt consists of the following:



	March 31, 2015					December 31, 2014
(millions, except percentages)	Debt			Interest Rate		Debt			Interest Rate
Credit Facility, due October 3, 2018	$	—		—	%	$	—		—	%
Capital Lease and Other Obligations	419			—	%	413			—	%
8.25% Senior Notes, due March 1, 2019	1,000			8.25	%	1,000			8.25	%
4.15% Senior Notes, due December 15, 2021	1,000			4.15	%	1,000			4.15	%
7.25% Senior Notes, due October 15, 2023	100			7.25	%	100			7.25	%
3.90% Senior Notes, due November 15, 2024	650			3.90	%	650			3.90	%
8.00% Senior Notes, due April 1, 2027	250			8.00	%	250			8.00	%
6.00% Senior Notes, due March 1, 2041	850			6.00	%	850			6.00	%
5.25% Senior Notes, due November 15, 2043	1,000			5.25	%	1,000			5.25	%
5.05% Senior Notes, due November 15, 2044	850			5.05	%	850			5.05	%
7.25% Senior Debentures, due August 1, 2097	84			7.25	%	84			7.25	%
Total	6,203					6,197
Unamortized Discount	(25		)			(26		)
Total Debt, Net of Discount	6,178					6,171
Less Amounts Due Within One Year
Capital Lease Obligations	(65		)			(68		)
Long-Term Debt Due After One Year	$	6,113				$	6,103

Credit Facility Our Credit Agreement provides for a $4.0 billion unsecured revolving credit facility (Credit Facility), which is available for general corporate purposes. The Credit Facility (i) provides for facility fee rates that range from 12.5 basis points to 30 basis points per year depending upon our credit rating, (ii) includes sub-facilities for short-term loans and letters of credit up to an aggregate amount of $500 million under each sub-facility and (iii) provides for interest rates that are based upon the Eurodollar rate plus a margin that ranges from 100 basis points to 145 basis points depending upon our credit rating.

See Note 7. Fair Value Measurements and Disclosures for a discussion of methods and assumptions used to estimate the fair values of debt.