Discontinued Operations Discontinued Operations Summary of Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended			24 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Revenue									$ 0	$ 87,534	$ 176,761
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax									777	160,612	0
Discontinued Operation Transaction Expenses												$ 11,100
Discontinued Operation Gain Loss From Disposal Of Discontinued Operation Before Income Taxes Net of Transaction Costs									706	151,550	0
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax									706	156,025	13,177
Discontinued Operation, Tax Effect of Discontinued Operation									(4,441)	83,614	5,216
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	$ 4,662	$ 289	$ 196	$ 0	$ 1,639	$ (55)	$ 69,312	$ 1,515	5,147	72,411	7,961
Comprehensive income attributable to noncontrolling interests									(90)	(236)	(1,217)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	$ 4,662	$ 289	$ 196	$ 0	$ 1,639	$ (55)	$ 69,617	$ 1,023	5,147	72,224	6,804
Ecova [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation Transaction Expenses									71	9,062	0	$ 9,100
Comprehensive income attributable to noncontrolling interests									$ 0	$ (187)	$ (1,157)