Debt is summarized as follows:


in thousands	*March 31* *2013*		December 31 2012		March 31 2012
Long-term Debt
Bank line of credit		$0		$0		$0
5.60% notes due 2012 ¹		0		0		134,521
6.30% notes due 2013 ²		140,430		140,413		140,367
10.125% notes due 2015 ³		152,520		152,718		153,284
6.50% notes due 2016 ⁴		514,221		515,060		517,503
6.40% notes due 2017 ⁵		349,892		349,888		349,874
7.00% notes due 2018 ⁶		399,741		399,731		399,702
10.375% notes due 2018 ⁷		248,716		248,676		248,562
7.50% notes due 2021 ⁸		600,000		600,000		600,000
7.15% notes due 2037 ⁹		239,555		239,553		239,547
Medium-term notes		6,000		16,000		16,000
Industrial revenue bonds		14,000		14,000		14,000
Other notes		949		964		1,098
Total long-term debt including current maturities		$2,666,024		$2,677,003		$2,814,458
Less current maturities		140,604		150,602		144,706
Total long-term debt		$2,525,420		$2,526,401		$2,669,752

Estimated fair value of long-term debt		$2,851,237		$2,766,835		$2,864,657

Includes decreases for unamortized discounts, as follows: March 31, 2012 — $36 thousand.

Includes decreases for unamortized discounts, as follows: March 31, 2013 — $14 thousand, December 31, 2012 — $30 thousand and March 31, 2012 — $77 thousand. The effective interest rate for these notes is 7.48%.

Includes an increase for the unamortized portion of the deferred gain realized upon the August 2011 settlement of interest rate swaps, as follows: March 31, 2013 — $2,766 thousand, December 31, 2012 — $2,983 thousand and March 31, 2012 — $3,604 thousand. Additionally, includes decreases for unamortized discounts, as follows: March 31, 2013 — $246 thousand, December 31, 2012 — $265 thousand and March 31, 2012 — $320 thousand. The effective interest rate for these notes is 9.59%.

⁴

Includes an increase for the unamortized portion of the deferred gain realized upon the August 2011 settlement of interest rate swaps, as follows: March 31, 2013 — $14,221 thousand, December 31, 2012 — $15,060 thousand and March 31, 2012 — $17,503 thousand. The effective interest rate for these notes is 6.02%.

⁵

Includes decreases for unamortized discounts, as follows: March 31, 2013 — $108 thousand, December 31, 2012 — $112 thousand and March 31, 2012 — $126 thousand. The effective interest rate for these notes is 7.41%.

⁶

Includes decreases for unamortized discounts, as follows: March 31, 2013 — $259 thousand, December 31, 2012 — $269 thousand and March 31, 2012 — $298 thousand. The effective interest rate for these notes is 7.87%.

⁷

Includes decreases for unamortized discounts, as follows: March 31, 2013 — $1,284 thousand, December 31, 2012 — $1,324 thousand and March 31, 2012 — $1,438 thousand. The effective interest rate for these notes is 10.62%.

⁸

The effective interest rate for these notes is 7.75%.

⁹

Includes decreases for unamortized discounts, as follows: March 31, 2013 — $633 thousand, December 31, 2012 — $635 thousand and March 31, 2012 — $641 thousand. The effective interest rate for these notes is 8.05%.