Debt Debt (Tables)

3 Months Ended

Mar. 31, 2013

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments [Table Text Block]

(Dollars in thousands)	March 31, 2013		December 31, 2012
Revenue bonds, fixed rate 5.9% to 7.75%, due 2013 through 2026	$	116,993	$	144,627
7.5% Senior Notes, due 2019	148,305		148,241
Debentures, 6.95%, due 2015	22,494		22,493
Medium-term notes, fixed rate 8.75% to 8.89%, due 2016 through 2022	27,250		27,250
Term loans, fixed rate 2.95% due 2017 and 3.70% due 2020	12,000		12,000
Fair value adjustment of hedged debt	2,706		2,952
Other notes	13		13
	329,761		357,576
Less current installments on long-term debt	9,013		8,413
Long-term debt	$	320,748	$	349,163

Schedule of Maturities of Long-term Debt [Table Text Block]

(Dollars in thousands)
2013	$	9,013
2014	—
2015	22,500
2016	5,000
2017	11,000