8. DEBT

The following table presents the primary components of our outstanding indebtedness with third parties and the weighted average interest rates associated with each component as of June 30, 2015, before the effect of our interest rate hedging activities. Our indebtedness with related parties is discussed in Note 10. Related Party Transactions.

	Interest			June 30,			December 31,
	Rate			2015			2014
				(in millions)
EEP debt obligations:
Commercial Paper⁽¹⁾		0.763	%	$	1,257.6		$	612.3
Credit Facilities due 2016 – 2019		1.22% – 3.25	%		810.0			1,160.0
Senior Notes due 2016		5.875	%		300.0			300.0
Senior Notes due 2018		7.000	%		100.0			100.0
Senior Notes due 2018		6.500	%		400.0			400.0
Senior Notes due 2019		9.875	%		500.0			500.0
Senior Notes due 2020		5.200	%		500.0			500.0
Senior Notes due 2021		4.200	%		600.0			600.0
Senior Notes due 2028		7.125	%		100.0			100.0
Senior Notes due 2033		5.950	%		200.0			200.0
Senior Notes due 2034		6.300	%		100.0			100.0
Senior Notes due 2038		7.500	%		400.0			400.0
Senior Notes due 2040		5.500	%		550.0			550.0
Junior subordinated notes due 2067		8.050	%		400.0			400.0
MEP debt obligations:
MEP Credit Agreement		2.413	%		410.0			360.0
MEP Series A Senior Notes due 2019		3.560	%		75.0			75.0
MEP Series B Senior Notes due 2021		4.040	%		175.0			175.0
MEP Series C Senior Notes due 2024		4.420	%		150.0			150.0
Total Principal of Debt Obligations					7,027.6			6,682.3
Other:
Unamortized Discount					(7.0	)		(7.1	)
Total Long Term Debt				$	7,020.6		$	6,675.2

⁽¹⁾	Individual issuances of commercial paper generally mature in 90 days or less, but are supported by our Credit Facilities and are therefore considered long-term debt.

Interest Cost

Our interest cost for the three and six months ended June 30, 2015, and 2014, is comprised of the following:

	For the three months				For the six months
	ended June 30,				ended June 30,
	2015		2014		2015		2014
	(in millions)
Interest expense	$	78.0	$	80.2	$	126.3	$	157.1
Less: Interest capitalized		6.1		10.2		18.3		24.1
Interest cost incurred	$	84.1	$	90.4	$	144.6	$	181.2

The $30.8 million decrease in interest expense for the six months ended June 30, 2015, as compared with the same period in 2014 was primarily due to changes to interest expense from ineffectiveness on hedging instruments.

Credit Facilities and Commercial Paper

We have a committed multi-year senior unsecured revolving credit facility, which we refer to as the Credit Facility, and a 364-day credit agreement, which we refer to as the 364-Day Credit Facility. We refer to our Credit Facility and our 364-Day Credit Facility as the Credit Facilities. The Credit Facility permits aggregate borrowings of up to, at any one time outstanding, $1.975 billion. The maturity date on the Credit Facility is September 26, 2019; however, $175.0 million of commitments will expire on the original maturity date of September 26, 2018. At June 30, 2015, we had $810.0 million outstanding under our Credit Facilities at a weighted average interest rate of 1.59%. During the six months ended June 30, 2015, we had net repayments of $350.0 million, which includes gross borrowings of $6,885.0 million and gross repayments of $7,235.0 million.

On July 2, 2015, we amended our 364-Day Credit Facility to extend the revolving credit termination date from July 3, 2015 to July 1, 2016. We further amended the 364-Day Credit Facility, to decrease the aggregate commitments from $650.0 million to $525.0 million: (1) on a revolving basis for a 364-day period, extendible annually at the lenders' discretion, and (2) for a 364-day term on a non-revolving basis following the expiration of all revolving periods. After the amendment to the 364-Day Credit Facility, the Credit Facilities provide an aggregate amount of approximately $2.5 billion of bank credit, as of July 2, 2015, which we use to fund our general activities and working capital needs.

In addition, we have a credit agreement with Enbridge (U.S.) Inc., an affiliate of Enbridge, or the EUS 364-day Credit Facility, that permits aggregate borrowing of up to, at any one time outstanding, $750.0 million, which is discussed in Note 9. Related Party Transactions.

We have a commercial paper program that provides for the issuance of up to an aggregate principal amount of $1.5 billion of commercial paper and is supported by our Credit Facilities. We access the commercial paper market primarily to provide temporary financing for our operating activities, capital expenditures and acquisitions when the available interest rates we can obtain are lower than the rates available under our Credit Facilities. At June 30, 2015, we had approximately $1,257.6 million in principal amount of commercial paper outstanding at a weighted average interest rate of 0.76%, excluding the effect of our interest rate hedging activities. Under our commercial paper program, we had net borrowings of approximately $644.9 million during the six months ended June 30, 2015, which includes gross borrowings of $5,717.3 million and gross repayments of $5,072.4 million. At December 31, 2014, we had approximately $612.3 million in principal amount of commercial paper outstanding at a weighted average interest rate of 0.50%, excluding the effect of our interest rate hedging activities. Our policy is to limit the amount of commercial paper we can issue by the amounts available under our Credit Facility up to an aggregate principal amount of $1.5 billion.

We have an uncommitted letter of credit arrangement, pursuant to which the lender may, on a discretionary basis and with no commitment, agree to issue standby letters of credit upon our request. The aggregate amount of this uncommitted letter of credit is not to exceed $220.0 million. While the letter of credit arrangement is uncommitted and issuance of letters of credit is at the lender's sole discretion, we view this arrangement as a liquidity enhancement as it allows us to potentially reduce our reliance on utilizing our committed Credit Facilities for issuance of letters of credit to support our hedging activities.

The amounts we may borrow under the terms of our Credit Facilities are reduced by the face amount of our letters of credit outstanding. Our policy is to maintain availability at any time under our Credit Facilities amounts that are at least equal to the amount of commercial paper that we have outstanding at any time.

At June 30, 2015, we had approximately $990.2 million available under the terms of our Credit Facilities and the EUS 364-day Credit Facility, determined as follows:

	(in millions)
Total credit available under our Credit Facilities⁽¹⁾	$	2,625.0
Total credit available under the EUS 364-day Credit Facility		750.0
Less: Amounts outstanding under our Credit Facilities		810.0
Principal amount of commercial paper outstanding		1,257.6
EUS 364-day Credit Facility⁽²⁾		—
Letters of credit outstanding		317.2
Total amount available at June 30, 2015	$	990.2

	⁽¹⁾	On July 2, 2015, we had an amendment to our 364-day Credit Facility. After the amendment on a pro-forma basis our total credit available under our Credit Facilities is $2,500.0 million, and the total amount available under the Credit Facilities and the EUS 364-day Credit Facility, less amounts outstanding, is $865.2 million.
	⁽²⁾	Refer to Note 9. Related Party Transactions for further details regarding the EUS 364-day Credit Facility.

As of June 30, 2015, we were in compliance with the terms of all of our financial covenants under our Credit Facilities and the EUS 364-day Credit Facility.

MEP Credit Agreement

MEP, Midcoast Operating, and their material domestic subsidiaries are party to a senior revolving credit facility, which we refer to as the MEP Credit Agreement, which permits aggregate borrowings of up to, at any one time outstanding, $850.0 million. The original term of the MEP Credit Agreement was three years with an initial maturity date of November 13, 2016, subject to four one-year requests for extensions. On September 30, 2014, MEP amended the MEP Credit Agreement to extend the maturity date from November 13, 2016, to September 30, 2017; however, $140.0 million of commitments will expire on the original maturity date of November 13, 2016.

At June 30, 2015, MEP had $410.0 million in outstanding borrowings under the MEP Credit Agreement at a weighted average interest rate of 2.4%. Under the MEP Credit Agreement, MEP had net borrowings of approximately $50.0 million during the six months ended June 30, 2015, which includes gross borrowings of $2,505.0 million and gross repayments of $2,455.0 million. As of June 30, 2015, MEP was in compliance with the terms of its financial covenants.

MEP Senior Notes

MEP's senior notes in the aggregate amount of $400.0 million were issued in a private placement on September 30, 2014 consist of three tranches: $75.0 million of 3.56% Series A Senior Notes due in 2019; $175.0 million of 4.04% Series B Senior Notes due in 2021; and $150.0 million of 4.42% Series C Senior Notes due in 2024, collectively the Notes. All of the Notes pay interest semi-annually on March 31 and September 30, which commenced on March 31, 2015. At June 30, 2015, MEP was in compliance with the terms of its financial covenants under the note purchase agreement.

Fair Value of Debt Obligations

The carrying amounts of our outstanding commercial paper, borrowings under our Credit Facilities, and the MEP Credit Agreement approximate their fair values at June 30, 2015, and December 31, 2014, respectively, due to the short-term nature and frequent repricing of the amounts outstanding under these obligations. The fair value of our outstanding commercial paper and borrowings under our Credit Facilities and the MEP Credit Agreement are included with our long-term debt obligations above since we have the ability and the intent to refinance the amounts outstanding on a long-term basis.

The approximate fair values of our fixed-rate debt obligations was $5.0 billion and $5.1 billion at June 30, 2015, and December 31, 2014, respectively. We determined the approximate fair values using a standard methodology that incorporates pricing points that are obtained from independent, third-party investment dealers who actively make markets in our debt securities. We use these pricing points to calculate the present value of the principal obligation to be repaid at maturity and all future interest payment obligations for any debt outstanding. The fair value of our long-term debt obligations is categorized as Level 2 within the fair value hierarchy.