XML 51 R40.htm IDEA: XBRL DOCUMENT v3.19.2
Regulatory Assets and Liabilities (Details) - USD ($)
$ in Thousands
Jun. 30, 2019
Dec. 31, 2018
Regulatory Assets [Line Items]    
Net Regulatory Assets $ 97,650 $ 103,625
Less: current regulatory asset, net 15,904 26,910
Total regulatory assets, net, less current portion 81,746 76,715
Total regulatory liability in Consolidated Balance Sheets 57,901 59,149
Deferred Income Tax Charge [Member]    
Regulatory Assets [Line Items]    
Regulatory Liabilities 57,901 59,149
Postretirement pensions and other medical benefits    
Regulatory Assets [Line Items]    
Regulatory assets: 66,233 66,233
Balancing and memorandum accounts, net    
Regulatory Assets [Line Items]    
Regulatory assets: 28,177 34,413
Other, net    
Regulatory Assets [Line Items]    
Regulatory assets: $ 3,240 $ 2,979