Discontinued Operations Discontinued Operations Summary of Cash Proceeds from Sale of Discontinued Operations (Details) - USD ($) $ in Thousands	12 Months Ended			24 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Jun. 30, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business Disposition Contract Sales Price					$ 335,000
Business Dispositions Tax Payments Made	$ (590)	$ (74,842)
Business Disposition Contract Price Closing Adjustments				$ 4,103
Business Disposition Adjusted Contract Price				339,691
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents					$ (95,932)
Proceeds from Divestiture of Business Before Tax Payments		205,400		219,180
Proceeds from Divestiture of Businesses, Net of Cash Divested	13,856	229,903	$ 0	243,759
Repayment of borrowings from Ecova line of credit	0	(46,000)	(11,000)
Payments for Repurchase of Redeemable Noncontrolling Interest	0	(20,871)	0
Payments to Noncontrolling Interests	0	$ (54,179)	$ 0
Transaction Expenses Withheld from Sales Proceeds				(5,461)
Proceeds from Divestiture of Businesses				143,748
Ecova [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Repayment of borrowings from Ecova line of credit	$ (40,000)
Ecova [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Litigation Settlement, Amount				$ 588