Debt and Credit Arrangements

Long-Term Debt

A summary of the carrying amounts and fair values of our long-term debt is listed below.



	Effective Interest Rate	March 31, 2018				December 31, 2017
	Effective Interest Rate	Book Value		Fair Value ¹		Book Value		Fair Value ¹
4.00% Senior Notes due 2022 (less unamortized discount and issuance costs of $1.2 and $1.0, respectively)	4.13%	$	247.8	$	253.0	$	247.6	$	259.0
3.75% Senior Notes due 2023 (less unamortized discount and issuance costs of $0.8 and $2.0, respectively)	4.32%	497.2		499.9		497.1		513.2
4.20% Senior Notes due 2024 (less unamortized discount and issuance costs of $0.6 and $2.5, respectively)	4.24%	496.9		509.0		496.7		524.2
Other notes payable and capitalized leases		48.4		48.4		46.2		46.2
Total long-term debt		1,290.3				1,287.6
Less: current portion		2.1				2.0
Long-term debt, excluding current portion		$	1,288.2			$	1,285.6


1	See Note 12 for information on the fair value measurement of our long-term debt.

Credit Agreements

We maintain a committed corporate credit facility, which has been amended and restated from time to time (the "Credit Agreement"). We use our Credit Agreement to increase our financial flexibility, to provide letters of credit primarily to support obligations of our subsidiaries and to support our commercial paper program. The Credit Agreement is a revolving facility, expiring in October 2022, under which amounts borrowed by us or any of our subsidiaries designated under the Credit Agreement may be repaid and reborrowed, subject to an aggregate lending limit of $1,500.0, or the equivalent in other currencies. The Company has the ability to increase the commitments under the Credit Agreement from time to time by an additional amount of up to $250.0, provided the Company receives commitments for such increases and satisfies certain other conditions. The aggregate available amount of letters of credit outstanding may decrease or increase, subject to a sublimit on letters of credit of $50.0, or the equivalent in other currencies. Our obligations under the Credit Agreement are unsecured. As of March 31, 2018, there were no borrowings under the Credit Agreement; however, we had $8.5 of letters of credit under the Credit Agreement, which reduced our total availability to $1,491.5. We were in compliance with all of our covenants in the Credit Agreement as of March 31, 2018.

We also have uncommitted lines of credit with various banks, which permit borrowings at variable interest rates and which are primarily used to fund working capital needs. We have guaranteed the repayment of some of these borrowings made by certain subsidiaries. If we lose access to these credit lines, we would have to provide funding directly to some of our operations. As of March 31, 2018, the Company had uncommitted lines of credit in an aggregate amount of $1,150.8, under which we had outstanding borrowings of $178.5 classified as short-term borrowings on our Consolidated Balance Sheet. The average amount outstanding during the first quarter of 2018 was $111.3, with a weighted-average interest rate of approximately 3.5%.

Commercial Paper

We have a commercial paper program under which the Company is authorized to issue unsecured commercial paper up to a maximum aggregate amount outstanding at any time of $1,500.0. Borrowings under the program are supported by the Credit Agreement described above. Proceeds of the commercial paper are used for working capital and general corporate purposes, including the repayment of maturing indebtedness and other short-term liquidity needs. The maturities of the commercial paper vary but may not exceed 397 days from the date of issue. As of March 31, 2018, there was $620.9 commercial paper outstanding. The average amount outstanding under the program during the first quarter of 2018 was $453.4, with a weighted-average interest rate of 2.1% and a weighted-average maturity of sixteen days.