LONG-TERM DEBT

We provide detail on our long-term debt balances, net of discounts, premiums, and debt issuance costs, in the following table at the end of the 2018 second quarter and year-end 2017:



	At Period End
($ in millions)	June 30, 2018			December 31, 2017
Senior Notes:
Series K Notes, interest rate of 3.0%, face amount of $600, maturing March 1, 2019 (effective interest rate of 4.4%)	$	599		$	598
Series L Notes, interest rate of 3.3%, face amount of $350, maturing September 15, 2022 (effective interest rate of 3.4%)	348			348
Series M Notes, interest rate of 3.4%, face amount of $350, maturing October 15, 2020 (effective interest rate of 3.6%)	348			348
Series N Notes, interest rate of 3.1%, face amount of $400, maturing October 15, 2021 (effective interest rate of 3.4%)	397			397
Series O Notes, interest rate of 2.9%, face amount of $450, maturing March 1, 2021 (effective interest rate of 3.1%)	448			447
Series P Notes, interest rate of 3.8%, face amount of $350, maturing October 1, 2025 (effective interest rate of 4.0%)	345			345
Series Q Notes, interest rate of 2.3%, face amount of $750, maturing January 15, 2022 (effective interest rate of 2.5%)	744			744
Series R Notes, interest rate of 3.1%, face amount of $750, maturing June 15, 2026 (effective interest rate of 3.3%)	743			743
Series S Notes, interest rate of 6.8%, face amount of $324, matured May 15, 2018 (effective interest rate of 1.7%)	—			330
Series T Notes, interest rate of 7.2%, face amount of $181, maturing December 1, 2019 (effective interest rate of 2.3%)	192			197
Series U Notes, interest rate of 3.1%, face amount of $291, maturing February 15, 2023 (effective interest rate of 3.1%)	291			291
Series V Notes, interest rate of 3.8%, face amount of $318, maturing March 15, 2025 (effective interest rate of 2.8%)	336			337
Series W Notes, interest rate of 4.5%, face amount of $278, maturing October 1, 2034 (effective interest rate of 4.1%)	292			292
Series X Notes, interest rate of 4.0%, face amount of $450, maturing April 15, 2028 (effective interest rate of 4.2%)	443			—
Commercial paper	3,079			2,371
Credit Facility	—			—
Capital lease obligations	168			171
Other	218			279
	$	8,991		$	8,238
Less: Current portion of long-term debt	(616		)	(398		)
	$	8,375		$	7,840

We paid cash for interest, net of amounts capitalized, of $144 million in the 2018 first half and $123 million in the 2017 first half.

We are party to a multicurrency revolving credit agreement (the “Credit Facility”) that provides for up to $4,000 million of aggregate effective borrowings to support our commercial paper program and general corporate needs, including working capital, capital expenditures, share repurchases, letters of credit, and acquisitions. Borrowings under the Credit Facility generally bear interest at LIBOR (the London Interbank Offered Rate) plus a spread, based on our public debt rating. We also pay quarterly fees on the Credit Facility at a rate based on our public debt rating. While any outstanding commercial paper borrowings and/or borrowings under our Credit Facility generally have short-term maturities, we classify the outstanding borrowings as long-term based on our ability and intent to refinance the outstanding borrowings on a long-term basis. The Credit Facility expires on June 10, 2021. See the “Cash Requirements and Our Credit Facility” caption later in this report in the “Liquidity and Capital Resources” section of Item 2 below for further information on our Credit Facility and available borrowing capacity at June 30, 2018.

In the 2018 second quarter, we issued $450 million aggregate principal amount of 4.000 percent Series X Notes due April 15, 2028 (the “Series X Notes”). We will pay interest on the Series X Notes on April 15 and October 15 of each year, commencing on October 15, 2018. We received net proceeds of approximately $443 million from the offering of the Series X Notes, after deducting the underwriting discount and estimated expenses. We expect to use these proceeds for general corporate purposes, which may include working capital, capital expenditures, acquisitions, stock repurchases, or repayment of outstanding commercial paper or other borrowings.