Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
Income taxes, refunds	$ 7,438	$ 21,459	$ 17,522
Income taxes (net of refunds of $7,438, $21,459 and $17,522 in 2019, 2018 and 2017, respectively)(a)	170,450	157,758	320,222
Interest (net of capitalization)	45,532	49,762	61,243
Capital expenditures included in Accounts payable	$ 199,451	$ 134,784	$ 89,188