Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018
Supplemental Cash Flow Information [Abstract]
Interest (1)	[1]	$ 108,994	$ 133,148
Income Taxes, Net of Refunds Received		(331,778)	62,777
Interest Costs Capitalized		18,000	11,000
Accrued Capital Expenditures		626,000	724,000
Non-Cash Property Exchanges		$ 72,000	83,000
Non-Cash Investing From Other Property, Plant and Equipment			$ 48,000

[1] Net of capitalized interest of $18 million and $11 million for the six months ended June 30, 2019 and 2018, respectively.