DEBT (Tables)

12 Months Ended

Dec. 31, 2019

DEBT [Abstract]

Debt

	Effective
in thousands	Interest Rates	2019	2018
Short-term Debt
Bank line of credit expires 2021 1		$                  0	$       133,000
Total short-term debt		$                  0	$       133,000
Long-term Debt
Bank line of credit expires 2021 1		$                  0	$                  0
Floating-rate notes due 2020 2	2.89%	250,000	250,000
Floating-rate notes due 2021	2.85%	500,000	500,000
8.85% notes due 2021	8.88%	6,000	6,000
4.50% notes due 2025	4.65%	400,000	400,000
3.90% notes due 2027	4.00%	400,000	400,000
7.15% notes due 2037	8.05%	129,239	129,239
4.50% notes due 2047	4.59%	700,000	700,000
4.70% notes due 2048	5.42%	460,949	460,949
Other notes	6.46%	185	208
Total long-term debt - face value		$    2,846,373	$    2,846,396
Unamortized discounts and debt issuance costs		(62,033)	(67,016)
Total long-term debt - book value		$    2,784,340	$    2,779,380
Less current maturities		25	23
Total long-term debt - reported value		$    2,784,315	$    2,779,357
Estimated fair value of long-term debt		$    3,073,693	$    2,695,802

1	Borrowings on the bank line of credit are classified as short-term if we intend to repay within twelve months and as long-term if we have the intent and ability to extend payment beyond twelve months.
2	This debt is classified as long-term since we intend to refinance it, and we have the ability to do so by borrowing on our line of credit.

Schedule of Principal and Interest Debt Payments

in thousands	Total	Principal	Interest
Scheduled Debt Payments (excluding the line of credit)
2020 1	$      362,691	$     250,025	$     112,666
2021	605,685	506,026	99,659
2022	96,041	28	96,013
2023	96,041	30	96,011
2024	96,041	32	96,009

¹ The floating-rate notes due 2020 in the amount of $250,000 thousand are classified as long-term since we intend to refinance, and we have the ability to do so by borrowing on our line of credit.

Standby Letters of Credit

in thousands
Standby Letters of Credit
Risk management insurance	$       44,781
Reclamation/restoration requirements	7,819
Total	$       52,600