Discontinued Operations Summary of Income Statement Information (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax			$ 68,100,000
Contract price			335,000,000
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	69,617,000	1,445,000	70,640,000	2,566,000
Transaction expenses withheld from proceeds			5,390,000
Revenues	43,150,000	44,560,000	87,534,000	86,967,000
Gain on sale of Ecova (1)	161,100,000	0	161,100,000	0
Transaction expenses and accelerated employee benefits (2)	10,900,000
Gain on sale of Ecova, net of transaction expenses	152,124,000	0	152,124,000	0
Income before income taxes	154,190,000	2,593,000	156,599,000	5,459,000
Income tax expense	84,878,000	1,102,000	85,772,000	2,086,000
Net income from discontinued operations	69,312,000	1,491,000	70,827,000	3,373,000
Net income attributable to noncontrolling interests	289,000	(73,000)	(193,000)	(833,000)
Ecova [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transaction expenses and accelerated employee benefits (2)	8,976,000	0	8,976,000	0
Net income attributable to noncontrolling interests	$ 305,000	$ (46,000)	$ (187,000)	$ (807,000)