Other comprehensive income (Tables)

12 Months Ended

Dec. 31, 2011

ACCUMULATED OTHER COMPREHENSIVE LOSS: [Abstract]

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

	Treasury Rate Lock			Change in Fair Value of Cash Flow Hedges			Adjustments for Actuarially Determined Liabilities			Adjustments for Non-controlling Interest			Accumulated Other Comprehensive Loss
Balance at December 31, 2008	$	263		$	124,510		$	(564,744	)	$	(21,929	)	$	(461,900	)
Net increase in value of cash flow hedge	$	—		$	186,824		$	—		$	(31,162	)	$	154,700
Reclassification of cash flow hedges from other comprehensive income to earnings	$	—		$	(239,956	)	$	—		$	40,024		$	(198,970	)
Current period change	$	(83	)	$	—		$	(134,549	)	$	298		$	(134,334	)
Balance at December 31, 2009	$	180		$	71,378		$	(699,293	)	$	(12,769	)	$	(640,504	)
Net increase in value of cash flow hedge	$	—		$	140,985		$	—		$	(12,500	)	$	128,540
Reclassification of cash flow hedges from other comprehensive income to earnings	$	—		$	(166,276	)	$	—		$	7,248		$	(159,083	)
Elimination of noncontrolling interest from purchase of CNX Gas	$	—		$	—		$	—		$	18,026		$	18,026
Current period change	$	(84	)	$	—		$	(221,228	)	$	(5	)	$	(221,317	)
Balance at December 31, 2010	$	96		$	46,087		$	(920,521	)	$	—		$	(874,338	)
Net increase in value of cash flow hedge	$	—		$	200,699		$	—		$	—		$	200,699
Reclassification of cash flow hedges from other comprehensive income to earnings	$	—		$	(95,006	)	$	—		$	—		$	(95,006	)
Current period change	$	(96	)	$	—		$	(32,813	)	$	—		$	(32,909	)
Balance at December 31, 2011	$	—		$	151,780		$	(953,334	)	$	—		$	(801,554	)