Consolidated Condensed Statements of Comprehensive Income of Energen Corporation (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net Income	$ 131,287	$ 63,325	$ 188,693	$ 157,593
Other Comprehensive Income (Loss):
Current period change in fair value of commodity derivative instruments, net of tax of $68,741, $30,307, $61,243 and ($29,067)	112,158	49,449	99,923	(47,425)
Pension and postretirement plans:
Amortization of net obligation at transition, net of taxes of $25, $24, $50 and $48	47	44	93	89
Amortization of prior service cost, net of taxes of $30, $26, $59 and $52	55	48	110	97
Amortization of net loss, net of taxes of $413, $318, $826 and $635,	766	591	1,533	1,179
Total pension and postretirement plans	868	683	1,736	1,365
Current period change in fair value of interest rate swap, net of tax ($566) and ($830)	(1,051)	0	(1,542)	0
Comprehensive Income (Loss)	227,732	117,494	274,027	111,887
Commodity Contract [Member]
Other Comprehensive Income (Loss):
Reclassification adjustment for derivative instruments, net of tax	(15,797)	4,037	(15,303)	354
Interest Rate Swap [Member]
Other Comprehensive Income (Loss):
Reclassification adjustment for derivative instruments, net of tax	$ 267	$ 0	$ 520	$ 0