Income and Partnership Taxes - Income Before Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Domestic	$ (675,746)	$ 167,510	$ 185,749
Foreign	(52,412)	47,644	(24,353)
(Loss) income before taxes	$ (728,158)	$ 215,154	$ 161,396