Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Supplemental Cash Flow Information [Abstract]
Interest (1)	[1]	$ 77,828	$ 52,189
Income Taxes, Net of Refunds Received		81,960	(48,412)
Accrued Capital Expenditures		$ 415,000	$ 357,000

[1] Net of capitalized interest of $7 million and $9 million for the three months ended March 31, 2017 and 2016, respectively.