Supplemental Disclosure of Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Non-cash Investing and Financing Activities from Continuing Operations [Abstract]
Property, plant and equipment acquired with accrued liabilities	$ 56,571	$ 21,708
Supplemental Cash Flow Elements [Abstract]
Interest (net of amounts capitalized)	(30,672)	(36,928)
Income taxes	$ 8	$ (14,336)