Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental Cash Flow Information [Abstract]
Interest, Net of Capitalized Interest	$ 243,279	$ 275,305	$ 252,030
Income Taxes, Net of Refunds Received	75,634	188,946	(39,293)
Accrued Capital Expenditures	592,000	475,000	388,000
Non-cash investing and financing activities from property exchanges.	362,000	$ 282,000
Non-Cash Investing From Other Property, Plant and Equipment	$ 49,000
Non-cash investing and financing activities from the Yates transaction			$ 3,834,000