LONG-TERM DEBT

Long-term debt consisted of the following (in thousands of dollars):



	As of December 31,
	2017			2016
4.60% senior notes due 2045	$	1,000,000		$	1,000,000
3.75% senior notes due 2046	400,000			400,000
4.20% senior notes due 2047	400,000			—
British pound term loan	194,574			187,506
Euro term loan	131,956			120,900
Canadian dollar revolving credit facility	99,388			100,521
Capital lease obligations and other	84,274			71,109
	2,310,192			1,880,036
Less current maturities	(38,709		)	(19,966		)
Debt issuance costs and discounts	(23,447		)	(19,124		)
	$	2,248,036		$	1,840,946

Senior Notes

In May 2017, the Company issued $400 million of unsecured 4.20%Senior Notes (4.20% Notes) that mature on May 15, 2047. The 4.20% Notes require no principal payments until the maturity date and interest is payable semi-annually on May 15 and November 15, beginning on November 15, 2017. Prior to November 15, 2046, the Company may redeem the 4.20% Notes in whole at any time or in part from time to time at a “make-whole” redemption price. This redemption price is calculated by reference to the then-current yield on a U.S. treasury security with a maturity comparable to the remaining term of the 4.20% Notes plus 20 basis points, together with accrued and unpaid interest, if any, at the redemption date. Additionally, if the Company experiences specific kinds of changes in control, it will be required to make an offer to purchase the 4.20% Notes at 101% of their principal amount plus accrued and unpaid interest, if any, at the date of purchase. On or after November 15, 2046, the Company may redeem the 4.20% Notes in whole at any time or in part from time to time at 100% of their principal amount, together with accrued and unpaid interest, if any, to the redemption date. Costs and discounts of approximately $5.8 million associated with the issuance of the 4.20% Notes, representing underwriting fees and other expenses, have been recorded as a contra-liability within Long-term debt and is being amortized to interest expense over the term of the 4.20% Notes. The fair value of the 4.20% Notes was approximately $411 million as of December 31, 2017.

In May 2016, the Company issued $400 million of unsecured 3.75% Senior Notes (3.75% Notes) that mature on May 15, 2046. The 3.75% Notes require no principal payments until the maturity date and interest is payable semi-annually on May 15 and November 15, beginning on November 15, 2016. Prior to November 15, 2045, the Company may redeem the 3.75% Notes in whole at any time or in part from time to time at a “make-whole” redemption price. This redemption price is calculated by reference to the then-current yield on a U.S. treasury security with a maturity comparable to the remaining term of the 3.75% Notes plus 20 basis points, together with accrued and unpaid interest, if any, to the redemption date. Additionally, if the Company experiences specific kinds of changes in control, it will be required to make an offer to purchase the 3.75% Notes at 101% of their principal amount plus accrued and unpaid interest, if any, to the date of purchase. On or after November 15, 2045, the Company may redeem the 3.75% Notes in whole at any time or in part from time to time at 100% of their principal amount, together with accrued and unpaid interest, if any, to the redemption date. Costs and discounts of approximately $7 million associated with the issuance of the 3.75% Notes, representing underwriting fees and other expenses, have been recorded as a contra-liability within Long-term debt and is being amortized to interest expense over the term of the 3.75% Notes. The fair value of the 3.75% Notes was approximately $384 million and $371 million as of December 31, 2017 and 2016, respectively.

In June 2015, the Company issued $1 billion of unsecured 4.60% Senior Notes (4.60% Notes) that mature on June 15, 2045. The 4.60% Notes require no principal payments until the maturity date and interest is payable semi-annually on June 15 and December 15, beginning on December 31, 2015. Prior to December 15, 2044, the Company may redeem the 4.60% Notes in whole at any time or in part from time to time at a “make-whole” redemption price. This redemption price is calculated by reference to the then-current yield on a U.S. treasury security with a maturity comparable to the remaining term of the 4.60% Notes plus 25 basis points, together with accrued and unpaid interest, if any, to the redemption date. Additionally, if the Company experiences specific kinds of changes in control, it will be required to make an offer to purchase the 4.60% Notes at 101% of their principal amount plus accrued and unpaid interest, if any, to the date of purchase. On or after December 15, 2044, the Company may redeem the 4.60% Notes in whole at any time or in part from time to time at 100% of their principal amount, together with accrued and unpaid interest, if any, to the redemption date. Costs and discounts of approximately $11 million associated with the issuance of the 4.60% Notes, representing underwriting fees and other expenses, have been recorded as a contra-liability within Long-term debt and is beingamortized to interest expense over the term of the 4.60% Notes. The fair value of the 4.60% Notes was approximately $1.1 billion as of December 31, 2017 and 2016.

The estimated fair values of the Company’s Senior Notes were based on available external pricing data and current market rates for similar debt instruments, among other factors, which are classified as level 2 inputs within the fair value hierarchy.

British Pound Term Loan

In August 2015, the Company entered into an unsecured credit facilities agreement providing for a five-year term loan of £160 million and revolving credit facility of up to £20 million (see Note 7 to the Consolidated Financial Statements). Proceeds of the term loan were used to partially fund the acquisition of Cromwell and to pay certain costs related to the acquisition. Under the agreement, the principal amount of the term loan will be repaid semiannually in installments of £4 million beginning February 2016 through February 2020 with the remaining outstanding amount due August 2020. At the election of the Company, the term loan bears interest at the LIBOR Rate plus a margin of 75 basis points, as defined within the term loan agreement. At December 31, 2017, the Company had elected a one-month LIBOR interest period. The weighted average interest rate was 1.04% and 1.17% for the years ended December 31, 2017 and 2016, respectively. The carrying value of the British Pound term loan approximates fair value due to the variable interest rate.

Euro Term Loan

On August 31, 2016, the Company entered into an agreement for a five-year term loan of €110 million and a revolving credit facility of up to €20 million (see Note 7 to the Consolidated Financial Statements). The proceeds from the term loan were used to pay in full €102.5 million of a term loan that matured in August 2016. Under the agreement, no principal amount of the loan will be required to be paid until the loan becomes due on August 31, 2021, at which time the loan will be required to be paid in full. The Company, at its option, may prepay this term loan in whole or in part at the end of any interest period without penalty. The loan bears interest at the EURIBOR plus a margin of 45 basis points, as defined within the term loan agreement. If EURIBOR is less than zero, then EURIBOR will be deemed to be zero. The interest rate at December 31, 2017, was 0.45%. The carrying value of the Euro term loan approximates fair value due to the variable interest rate.

Canadian Dollar Revolving Credit Facility

In September 2014, the Company entered into an unsecured revolving credit facility with a maximum availability of C$175 million. Pursuant to the credit agreement, there is a commitment fee of 0.07% as of December 31, 2017, and the facility matures on September 24, 2019. The amounts outstanding were C$125 million and C$135 million as of December 31, 2017 and 2016, respectively. The loan bears interest at the Canadian Dollar Offered Rate (CDOR) plus a margin of 70 basis points, as defined within the loan agreement. The weighted average interest rate during the year on this outstanding amount was 1.78%. No principal payments are required on the credit facility until the maturity date. Accordingly, the amount outstanding is included in long-term debt as of December 31, 2017. The carrying value of the Canadian Dollar revolving credit facility approximates fair value due to the variable interest rate.

The scheduled aggregate principal payments related to capital lease obligations and long-term debt, excluding debt issuance costs, are due as follows (in thousands of dollars):



Year	Payment Amount
2018	$	38,709
2019	144,156
2020	190,774
2021	136,543
2022	10
Thereafter	1,800,000
Total	$	2,310,192

The Company's debt instruments include affirmative and negative covenants that are usual and customary for companies with similar credit ratings. The Company was in compliance with all debt covenants as December 31, 2017.