XML 127 R107.htm IDEA: XBRL DOCUMENT v3.20.4
Schedule 1 - Condensed Financial Information of Registrant - Related Party Transactions (Details) - Otter Tail Corporation - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Related Party Transaction [Line Items]    
Accounts Receivable from Subsidiaries $ 2,734 $ 2,144
Interest Receivable from Subsidiaries 117 117
Current Notes Receivable 0 0
Notes Receivable from Subsidiaries 79,069 79,251
Accounts Payable 7 7
Notes Payable to Subsidiaries 134,352 89,611
OTP    
Related Party Transaction [Line Items]    
Accounts Receivable from Subsidiaries 2,698 2,056
Interest Receivable from Subsidiaries 0 0
Current Notes Receivable 0 0
Notes Receivable from Subsidiaries 0 0
Accounts Payable 7 7
Notes Payable to Subsidiaries 0 0
Northern Pipe Products, Inc.    
Related Party Transaction [Line Items]    
Accounts Receivable from Subsidiaries 0 0
Interest Receivable from Subsidiaries 8 8
Current Notes Receivable 0 0
Notes Receivable from Subsidiaries 5,169 5,351
Accounts Payable 0 0
Notes Payable to Subsidiaries 9,103 3,056
Vinyltech Corporation    
Related Party Transaction [Line Items]    
Accounts Receivable from Subsidiaries 0 4
Interest Receivable from Subsidiaries 17 17
Current Notes Receivable 0 0
Notes Receivable from Subsidiaries 11,500 11,500
Accounts Payable 0 0
Notes Payable to Subsidiaries 18,004 15,099
BTD Manufacturing, Inc.    
Related Party Transaction [Line Items]    
Accounts Receivable from Subsidiaries 0 0
Interest Receivable from Subsidiaries 77 77
Current Notes Receivable 0 0
Notes Receivable from Subsidiaries 52,000 52,000
Accounts Payable 0 0
Notes Payable to Subsidiaries 30,344 18,474
T.O. Plastics, Inc.    
Related Party Transaction [Line Items]    
Accounts Receivable from Subsidiaries 0 0
Interest Receivable from Subsidiaries 15 15
Current Notes Receivable 0 0
Notes Receivable from Subsidiaries 10,400 10,400
Accounts Payable 0 0
Notes Payable to Subsidiaries 3,101 3,099
Varistar Corporation    
Related Party Transaction [Line Items]    
Accounts Receivable from Subsidiaries 0 0
Interest Receivable from Subsidiaries 0 0
Current Notes Receivable 0 0
Notes Receivable from Subsidiaries 0 0
Accounts Payable 0 0
Notes Payable to Subsidiaries 73,800 49,883
Otter Tail Assurance Limited    
Related Party Transaction [Line Items]    
Accounts Receivable from Subsidiaries 36 84
Interest Receivable from Subsidiaries 0 0
Current Notes Receivable 0 0
Notes Receivable from Subsidiaries 0 0
Accounts Payable 0 0
Notes Payable to Subsidiaries $ 0 $ 0