XML 71 R52.htm IDEA: XBRL DOCUMENT v3.20.2
Regulatory matters - Regulatory Assets and Liabilities (Detail)
$ in Thousands
Jun. 30, 2020
USD ($)
Mar. 01, 2020
jurisdiction
Dec. 31, 2019
USD ($)
Regulatory Liabilities [Line Items]      
Total regulatory assets $ 753,641   $ 559,887
Less: current regulatory assets (43,558)   (50,213)
Non-current regulatory assets 710,083   509,674
Total regulatory liabilities 608,826   598,062
Less: current regulatory liabilities (31,720)   (41,683)
Non-current regulatory liabilities 577,106   556,379
Income taxes      
Regulatory Liabilities [Line Items]      
Total regulatory liabilities 331,991   321,960
Cost of removal      
Regulatory Liabilities [Line Items]      
Total regulatory liabilities 195,277   196,423
Rate base offset      
Regulatory Liabilities [Line Items]      
Total regulatory liabilities 7,342   8,719
Fuel and commodity costs adjustments      
Regulatory Liabilities [Line Items]      
Total regulatory liabilities 19,090   16,645
Rate adjustment mechanism      
Regulatory Liabilities [Line Items]      
Total regulatory liabilities 4,514   10,446
Deferred capitalized costs - fuel related      
Regulatory Liabilities [Line Items]      
Total regulatory liabilities 7,017   7,097
Pension and post-employment benefits      
Regulatory Liabilities [Line Items]      
Total regulatory liabilities 24,460   22,256
Other      
Regulatory Liabilities [Line Items]      
Total regulatory liabilities 19,135   14,516
Retired generating plant      
Regulatory Liabilities [Line Items]      
Number of Commission Jurisdictions | jurisdiction   3  
Total regulatory assets 196,476   0
Environmental remediation      
Regulatory Liabilities [Line Items]      
Total regulatory assets 88,914   82,300
Pension and post-employment benefits      
Regulatory Liabilities [Line Items]      
Total regulatory assets 136,901   143,292
Income taxes      
Regulatory Liabilities [Line Items]      
Total regulatory assets 73,662   71,506
Debt premium      
Regulatory Liabilities [Line Items]      
Total regulatory assets 38,462   42,150
Fuel and commodity costs adjustments      
Regulatory Liabilities [Line Items]      
Total regulatory assets 7,736   23,433
Rate adjustment mechanism      
Regulatory Liabilities [Line Items]      
Total regulatory assets 77,173   69,121
Clean energy and other customer programs      
Regulatory Liabilities [Line Items]      
Total regulatory assets 26,510   26,369
Deferred capitalized costs      
Regulatory Liabilities [Line Items]      
Total regulatory assets 37,920   38,833
Asset retirement obligation      
Regulatory Liabilities [Line Items]      
Total regulatory assets 25,631   23,841
Long-term maintenance contract      
Regulatory Liabilities [Line Items]      
Total regulatory assets 14,913   13,264
Rate review costs      
Regulatory Liabilities [Line Items]      
Total regulatory assets 7,000   6,695
Other      
Regulatory Liabilities [Line Items]      
Total regulatory assets $ 22,343   $ 19,083