Discontinued Operations Discontinued Operations Summary of Income Statement Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended			24 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	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
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax									$ 0	777	160,612
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
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax										706	156,025
Discontinued Operation, Tax Effect of Discontinued Operation										(4,441)	83,614
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest					$ 4,662	$ 289	$ 196	$ 0	0	5,147	72,411
Comprehensive income attributable to noncontrolling interests	$ (12)	$ (27)	$ (33)	$ (16)	(17)	(32)	(28)	(13)	(88)	(90)	(236)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent					$ 4,662	$ 289	$ 196	$ 0	$ 0	5,147	72,224
Transaction Expenses Withheld from Sales Proceeds												(5,500)
Ecova [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation Transaction Expenses										71	9,062	$ 9,100
Comprehensive income attributable to noncontrolling interests										$ 0	$ (187)