XML 59 R43.htm IDEA: XBRL DOCUMENT v3.22.0.1
Summary of Significant Accounting Policies - Advances for Construction and Contributions in Aid of Construction (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Estimated Refunds of Advances for Construction [Abstract]    
2022 $ 3,609  
2023 3,548  
2024 3,282  
2025 3,030  
2026 2,809  
Thereafter 49,582  
Advances for construction 130,693 $ 125,027
Customer advances for construction, non-refundable 36,388  
Customer advances for construction, refunded on service connections $ 28,445  
Contract with customer, refund period 40 years  
Contract with customer, fair value of advances $ 51,067 $ 50,391
Amortization period for taxes paid relating to advances and contributions 40 years