Other Noncurrent Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Other Liabilities Disclosure [Abstract]
Pension and retiree medical obligations	$ 84,831	$ 99,417
Transition tax payable	14,208	14,208
Liability for uncertain tax positions	1,429	1,071
Deferred revenue	36,531	30,354
Lease liability	92,083	94,250
Other	26,288	27,497
Total other noncurrent liabilities	$ 255,370	$ 266,797