Other Assets - Composition of Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Benefit plan-related assets	$ 98,536	$ 84,600
Non-current deferred tax assets	103,559	79,618
Other	54,221	58,027
Total other assets	$ 256,316	$ 222,245