Reconciliation of Segment Information, Revenue and Other Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Domestic	$ (23,721)	$ 38,127	$ 106,459	$ 33,511
Total Reportable Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Domestic	142,977	101,178	327,685	200,192
Other Segments [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Domestic	1,755	4,887	3,252	7,461
Excludes Gas Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Interest Income (Expense), Net and Other Non-operating Activity	(144,013)	(56,403)	(197,956)	(109,063)
Fees for Disposing Non-core Assets	(24,440)	(11,535)	26,522	65,079
Intersegment Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Income (Loss) from Continuing Operations before Income Taxes, Domestic	$ (168,453)	$ (67,938)	$ (224,478)	$ (174,142)