Discontinued Operations And Assets Held For Sale (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended									12 Months Ended
	Jul. 31, 2014	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on sale of discontinued operations											$ 7,836	$ 12,566	$ 10,106
Tax provision (benefit) on sale of discontinued operations											2,743	899	(3,009)
Gain on disposal of discontinued operations, net of taxes		$ 3,793	$ 1,300	$ 0	$ 0	$ (6,518)	$ 7,685	$ 500	$ 0		$ 5,093	$ 1,667	13,115
Premier [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration from sale of business	$ 250,000
Pre-tax gain (loss) on sale of discontinued operations							$ 12,100
Power Production Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Pre-tax gain (loss) on sale of discontinued operations										$ 6,400
Empire [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration from sale of business													3,200
Tax provision (benefit) on sale of discontinued operations													(5,400)
Gain on disposal of discontinued operations, net of taxes													$ 8,600