DEBT (Tables)

12 Months Ended

Dec. 31, 2015

DEBT [Abstract]

Summary of Debt

	Effective
in thousands	Interest Rates	2015	2014
Short-term Debt
Bank line of credit expires 2020 1, 2, 3	n/a	$                  0	$                  0
Total short-term debt		$                  0	$                  0
Long-term Debt
Bank line of credit expires 20201, 2, 3	1.75%	$       235,000	$                  0
10.125% notes due 2015	n/a	0	150,000
6.50% notes due 2016	n/a	0	125,001
6.40% notes due 2017	n/a	0	218,633
7.00% notes due 2018	7.87%	272,512	400,000
10.375% notes due 2018	10.63%	250,000	250,000
7.50% notes due 2021	7.75%	600,000	600,000
8.85% notes due 2021	8.88%	6,000	6,000
Industrial revenue bond due 2022	n/a	0	14,000
4.50% notes due 2025	4.65%	400,000	0
7.15% notes due 2037	8.05%	240,188	240,188
Other notes 2	6.25%	498	637
Unamortized discounts and debt issuance costs	n/a	(23,734)	(22,716)
Unamortized deferred interest rate swap gain 4	n/a	0	3,036
Total long-term debt including current maturities 5		$    1,980,464	$    1,984,779
Less current maturities		130	150,137
Total long-term debt		$    1,980,334	$    1,834,642
Total debt 6		$    1,980,464	$    1,984,779
Estimated fair value of long-term debt		$    2,204,816	$    2,092,673

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 otherwise.
2	Non-publicly traded debt.
3	The effective interest rate is the spread over LIBOR as of the balance sheet dates.
4	The unamortized deferred gain was realized upon the August 2011 settlement of interest rate swaps as discussed in Note 5.
5	The debt balances as of December 31, 2014 have been adjusted to reflect our early adoption of ASU 2015-03 and related election as discussed in Note 1 under the caption New Accounting Standards.
6	Face value of our debt is equal to total debt plus unamortized discounts and debt issuance costs, and unamortized deferred interest rate swap gain, as follows: December 31, 2015 — $2,004,198 thousand and December 31, 2014 — $2,004,459 thousand.

Schedule of Principal and Interest Debt Payments

in thousands	Total	Principal	Interest
Debt Payments (excluding the line of credit)
2016	$      125,878	$           130	$    125,748
2017	125,878	138	125,740
2018	638,728	522,534	116,194
2019	80,740	23	80,717
2020	80,740	25	80,715

Summary of Standby Letters of Credit

in thousands
Standby Letters of Credit
Risk management insurance	$       33,111
Reclamation/restoration requirements	5,753
Total	$       38,864