CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net (loss) income for the period	$ (266,608)	$ 1,111,702	$ (1,099,710)	$ 1,307,713
Other comprehensive (loss) income, net of tax
Net (loss) gain from foreign currency translation	28,323	(17,128)	(39,520)	36,927
Retirement and postretirement benefit plans	3,726	2,761	(45,219)	8,277
Deferred loss on interest rate hedges reclassified to interest expense	297	585	905	1,756
Other comprehensive (loss) income	32,346	(13,782)	(83,834)	46,960
COMPREHENSIVE (LOSS) INCOME	$ (234,262)	$ 1,097,920	$ (1,183,544)	$ 1,354,673