Note 7: Debt

Debt is detailed as follows:



	Effective	March 31	December 31	March 31
in thousands	Interest Rates	2017	2016	2016
Short-term Debt
Bank line of credit expires 2021 1, 2, 3	n/a	$ 0	$ 0	$ 0
Total short-term debt		$ 0	$ 0	$ 0
Long-term Debt
Bank line of credit expires 2020 1, 2, 3	1.25%	$ 235,000	$ 235,000	$ 235,000
7.00% notes due 2018	7.87%	272,512	272,512	272,512
10.375% notes due 2018	10.63%	250,000	250,000	250,000
7.50% notes due 2021	7.75%	600,000	600,000	600,000
8.85% notes due 2021	8.88%	6,000	6,000	6,000
Delayed draw term loan 2, 3	1.25%	0	0	0
4.50% notes due 2025	4.65%	400,000	400,000	400,000
3.90% notes due 2027	4.06%	350,000	0	0
7.15% notes due 2037	8.05%	240,188	240,188	240,188
Other notes 3	6.31%	364	365	494
Total long-term debt - face value		$ 2,354,064	$ 2,004,065	$ 2,004,194
Unamortized discounts and debt issuance costs		(24,677)	(21,176)	(22,638)
Total long-term debt - book value		$ 2,329,387	$ 1,982,889	$ 1,981,556
Less current maturities		139	138	131
Total long-term debt - reported value		$ 2,329,248	$ 1,982,751	$ 1,981,425
Estimated fair value of long-term debt		$ 2,605,379	$ 2,243,213	$ 2,236,669


1	Borrowings on the bank line of credit are classified as short-term debt if we intend to repay within twelve months and as long-term debt if we have the intent and ability to extend payment beyond twelve months.
2	The effective interest rate is the spread over LIBOR as of the most recent balance sheet date.
3	Non-publicly traded debt.

Our total long-term debt - book value is presented in the table above net of unamortized discounts from par and unamortized deferred debt issuance costs. Discounts and debt issuance costs are amortized using the effective interest method over the terms of the respective notes resulting in $1,065,000 of net interest expense for these items for the three months ended March 31, 2017.

The estimated fair value of our debt presented in the table above was determined by: (1) averaging several asking price quotes for the publicly traded notes and (2) assuming par value for the remainder of the debt. The fair value estimates for the publicly traded notes were based on Level 2 information (as defined in Note 5) as of their respective balance sheet dates.

LINE OF CREDIT

In December 2016, among other favorable changes, we extended the maturity date of our unsecured $750,000,000 line of credit from June 2020 to December 2021 (incurring $1,876,000 of transaction fees together with the new term loan described below). The credit agreement contains affirmative, negative and financial covenants customary for an unsecured investment-grade facility. The primary negative covenant limits our ability to incur secured debt. The financial covenants are: (1) a maximum ratio of debt to EBITDA of 3.5:1 (upon certain acquisitions, the maximum ratio can be 3.75:1 for three quarters), and (2) a minimum ratio of EBITDA to net cash interest expense of 3.0:1. As of March 31, 2017, we were in compliance with the line of credit covenants.

Borrowings on our line of credit are classified as short-term debt if we intend to repay within twelve months and as long-term debt if we have the intent and ability to extend repayment beyond twelve months. Borrowings bear interest, at our option, at either LIBOR plus a credit margin ranging from 1.00% to 1.75%, or SunTrust Bank’s base rate (generally, its prime rate) plus a credit margin ranging from 0.00% to 0.75%. The credit margin for both LIBOR and base rate borrowings is determined by our credit ratings. Standby letters of credit, which are issued under the line of credit and reduce availability, are charged a fee equal to the credit margin for LIBOR borrowings plus 0.175%. We also pay a commitment fee on the daily average unused amount of the line of credit that ranges from 0.10% to 0.25% determined by our credit ratings. As of March 31, 2017, the credit margin for LIBOR borrowings was 1.25%, the credit margin for base rate borrowings was 0.25%, and the commitment fee for the unused amount was 0.15%.

As of March 31, 2017, our available borrowing capacity was $471,462,000. Utilization of the borrowing capacity was as follows:

$235,000,000 was borrowed

$43,538,000 was used to provide support for outstanding standby letters of credit

TERM DEBT

All of our term debt is unsecured. $2,118,700,000 of such debt is governed by two essentially identical indentures that contain customary investment-grade type covenants. The primary covenant in both indentures limits the amount of secured debt we may incur without ratably securing such debt. As of March 31, 2017, we were in compliance with all of the term debt covenants.

In March 2017, we issued $350,000,000 of 3.90% senior notes due April 2027 for proceeds of $345,450,000 (net of original issue discounts, underwriter fees and other transaction costs). The proceeds will be used for general corporate purposes.

In December 2016, we entered into an unsecured $250,000,000 delayed draw term loan (incurring, together with the line of credit extension mentioned previously, $1,876,000 of transaction costs). The term loan is provided by the same group of banks that provides our line of credit, and is governed by the same credit agreement as the line of credit. As such, it is subject to the same affirmative, negative, and financial covenants.

The 2016 term loan may be funded in up to three draws through June 21, 2017, after which any undrawn amount expires. Borrowings bear interest in the same manner as the line of credit. The term loan principal will be repaid quarterly beginning March 2018 as follows: quarters 5 - 8 @ 0.625%; quarters 9 - 12 @ 1.25%; quarters 13 - 19 @ 1.875% and quarter 20 @ 79.375%. The term loan may be prepaid at any time without penalty. As of March 31, 2017, no draws have been made under this term loan.

STANDBY LETTERS OF CREDIT

We provide, in the normal course of business, certain third-party beneficiaries standby letters of credit to support our obligations to pay or perform according to the requirements of an underlying agreement. Such letters of credit typically have an initial term of one year, typically renew automatically, and can only be modified or cancelled with the approval of the beneficiary. All of our standby letters of credit are issued by banks that participate in our $750,000,000 line of credit, and reduce the borrowing capacity thereunder. Our standby letters of credit as of March 31, 2017 are summarized by purpose in the table below:



in thousands
Standby Letters of Credit
Risk management insurance	$ 38,111
Reclamation/restoration requirements	5,427
Total	$ 43,538