Cost and Fair Value of Long-Term Debt (tables)

9 Months Ended

Sep. 30, 2012

Long-term Debt, Current and Noncurrent [Abstract]

Fair Value Of Long Term Debt Table [Text Block]

	September 30,				December 31,
Thousands	2012		2011		2011
Carrying amount	$	641,700	$	641,700	$	681,700
Estimated fair value	$	786,496	$	774,186	$	808,724