Provision (Benefit) for Income Taxes Textuals (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Aug. 10, 2018
Income Tax Contingency [Line Items]
Tax Credit Carryforward, Valuation Allowance	$ 105,000
Deferred Tax Liabilities, Net, Noncurrent	(1,524,000)	$ (3,147,000)
Foreign income (loss) in Income from continuing operations before income taxes	(3,000)	(7,000)	$ (885,000)
Minimum tax credit	71,000	155,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	31,000
Income Taxes Paid, Net	11,000	28,000	5,000
Unrecognized tax benefits	51,000	50,000	50,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	51,000	50,000
Total interest and penalties recognized as part of income tax provision	800	(400)	$ 300
Total interest and penalties accrued as uncertain tax positions	3,000	$ 2,000
Federal tax rate before Tax Reform [Member]
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent		35.00%
Federal tax rate after Tax Reform [Member]
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent		21.00%
Internal Revenue Service (IRS) [Member] | Expiration2019to2023 [Member]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards	5,000
Internal Revenue Service (IRS) [Member] | ExpirationNone [Member]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards	$ 142,000
WPZ Merger Public Unit Exchange [Member]
Income Tax Contingency [Line Items]
Deferred Tax Liabilities, Net, Noncurrent				$ 1,829,000