Divestitures Divestitures - Other Assets and Liabilities Held for Sale (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from divestitures, net	$ 413,569	$ 6,857	$ 3,325,571
Current assets	0	39,152
Net property, plant and equipment		215,900
Current liabilities	0	1,938
Assets held for sale, excluding discontinued operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash proceeds from divestitures, net	$ 413,600
Current assets		39,152
Net property, plant and equipment		121,759
Goodwill		14,422
Other intangibles, net of amortization		3,632
Assets held for sale		178,965
Current liabilities		1,938
Noncurrent liabilities		614
Liabilities held for sale		$ 2,552