Related Party Transactions (Investment Balance in Company's Equity Method Investees) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Equity Method Investment Companys Investment Balance In Each Equity Method Investees By Entity [Abstract]
Equity Method Investments	$ 26,461	$ 23,857
Providence Grain
Equity Method Investment Companys Investment Balance In Each Equity Method Investees By Entity [Abstract]
Equity Method Investments	12,467	12,424
Quadra Commodities S.A.
Equity Method Investment Companys Investment Balance In Each Equity Method Investees By Entity [Abstract]
Equity Method Investments	7,013	5,574
Other
Equity Method Investment Companys Investment Balance In Each Equity Method Investees By Entity [Abstract]
Equity Method Investments	$ 6,981	$ 5,859