Reconciliation of Segment Information, Revenue and Other Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 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	$ (3,033)	$ (3,311)	$ 103,426	$ 30,200
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	90,032	62,522	417,717	262,714
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	2,689	(2,385)	5,941	5,076
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	(79,366)	(57,479)	(277,322)	(166,542)
Fees for Disposing Non-core Assets	(16,388)	(5,969)	42,910	71,048
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	$ (95,754)	$ (63,448)	$ (320,232)	$ (237,590)