Condensed Consolidating Financial Information (Schedule Of Condensed Consolidating Statement Of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Oil and gas revenues	$ 129,728	$ 144,329	$ 134,224	$ 111,901	$ 107,450	$ 96,197	$ 83,818	$ 80,715	$ 520,182	$ 368,180	$ 202,167
Costs and expenses									367,123	269,527	164,016
Loss on sale of oil and gas properties									45,377	0	0
Operating income (loss)	(21,002)	48,603	46,618	33,463	37,151	24,318	14,806	22,380	107,682	98,653	38,151
Other income (expense), net									(72,921)	(16,520)	19,994
Income (loss) from continuing operations before income taxes									34,761	82,133	58,145
Income tax (expense) benefit									(12,903)	(30,956)	(25,611)
Equity in income (loss) of subsidiaries									0	0	0
Net income from continuing operations	(22,215)	5,712	35,837	2,524	16,763	(1,945)	25,683	10,676	21,858	51,177	32,534
Net income from discontinued operations, net of income taxes									21,825	4,310	4,095
NET INCOME	(23,989)	4,521	36,969	26,182	18,490	(930)	28,504	9,423	43,683	55,487	36,629
Parent Company [Member]
Oil and gas revenues									6,490	20,195	31,875
Costs and expenses									82,282	76,839	68,652
Loss on sale of oil and gas properties									0
Operating income (loss)									(75,792)	(56,644)	(36,777)
Other income (expense), net									(52,592)	20,022	41,182
Income (loss) from continuing operations before income taxes									(128,384)	(36,622)	4,405
Income tax (expense) benefit									44,934	12,658	(1,209)
Equity in income (loss) of subsidiaries									106,538	73,150	29,319
Net income from continuing operations									23,088	49,186	32,515
Net income from discontinued operations, net of income taxes									21,825	126	1,013
NET INCOME									44,913	49,312	33,528
Combined Guarantor Subsidiaries [Member]
Oil and gas revenues									513,692	347,985	170,292
Costs and expenses									284,076	205,341	100,255
Loss on sale of oil and gas properties									45,377
Operating income (loss)									184,239	142,644	70,037
Other income (expense), net									(20,329)	(36,542)	(21,188)
Income (loss) from continuing operations before income taxes									163,910	106,102	48,849
Income tax (expense) benefit									(57,369)	(37,136)	(22,612)
Equity in income (loss) of subsidiaries									0	0	0
Net income from continuing operations									106,541	68,966	26,237
Net income from discontinued operations, net of income taxes									0	0	0
NET INCOME									106,541	68,966	26,237
Combined Non-Guarantor Subsidiaries [Member]
Oil and gas revenues									0	0	0
Costs and expenses									3	0	0
Loss on sale of oil and gas properties									0
Operating income (loss)									(3)	0	0
Other income (expense), net									0	0	0
Income (loss) from continuing operations before income taxes									(3)	0	0
Income tax (expense) benefit									0	0	0
Equity in income (loss) of subsidiaries									0	0	0
Net income from continuing operations									(3)	0	0
Net income from discontinued operations, net of income taxes									0	4,184	3,082
NET INCOME									(3)	4,184	3,082
Eliminations [Member]
Oil and gas revenues									0	0	0
Costs and expenses									762	(12,653)	(4,891)
Loss on sale of oil and gas properties									0
Operating income (loss)									(762)	12,653	4,891
Other income (expense), net									0	0	0
Income (loss) from continuing operations before income taxes									(762)	12,653	4,891
Income tax (expense) benefit									(468)	(6,478)	(1,790)
Equity in income (loss) of subsidiaries									(106,538)	(73,150)	(29,319)
Net income from continuing operations									(107,768)	(66,975)	(26,218)
Net income from discontinued operations, net of income taxes									0	0	0
NET INCOME									$ (107,768)	$ (66,975)	$ (26,218)