XML 65 R51.htm IDEA: XBRL DOCUMENT v3.22.0.1
Investments - Narrative (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]      
SERP Investments at fair value $ 2,317 $ 2,687  
CoBank      
Schedule of Equity Method Investments [Line Items]      
SERP Investments at fair value 10,300 9,800  
Other nonoperating income (expense) $ 2,000 4,200 $ 4,200
Percentage of patronage credit paid in cash 75.00%    
Percentage of patronage credit paid in share 25.00%    
Valley Network Partnership      
Schedule of Equity Method Investments [Line Items]      
Ownership interest, percentage 20.00%    
Equity Method Investee      
Schedule of Equity Method Investments [Line Items]      
Revenue from related parties $ 700 900 1,000
Related party costs $ 1,200 $ 2,700 $ 3,000