find/add inter-table relationships when they include a second dimension

[cmgosnell]

Ex: in the income_statement_ferc1 table, there is an operating_revenues factoid. In the electric_operating_revenues_ferc1 there is a electric_operating_revenues factoid. They are conceptually related but not the same and do not have the same factoid name. The income_statement_ferc1 table & thus the operating_revenues has another dimension of the utility_type. So there is a line of operating_revenues in the income statement table which is electric.

This one is really easy to see bc it is {other_dimension}_{xbrl_factoid_name} but i expect it won't always be that straightforward.

If we add in the implied dimension in the tables where these dimensions are implied (which would probably be helpful anyway) and renamed the factoids to match we could convert these conceptual connections into more tangible ones that can be id-ed programmatically, checked and scrubbed for the 💥

- [x] HUNT DOWN all of these inter-table connections that don't link up by name (@jrea-rmi  if you have any pointers on this that would be vv helpful)
- [x] when required, add the other dimension into the implicitly-dimension-ed table (i.e. `assign(utility_type="electric")` to `electric_operating_revenues_ferc1`.
- [ ] possibly add check into the explosion (e.g. if dimension and factoid name the same, remove duplicate)

[e-belfer]

Will continue to update as I go through the tables

For the electric-specific columns of income_statement_ferc1 table:

• operating_revenues comes from Schedule 400 -> electric_operating_revenues (electric_operating_revenues_ferc1)

• operating_expense comes from Schedule 401 -> operation_supervision (electric_operating_expenses_ferc1)

• maintenance_expense comes from Schedule 402 -> maintenance_supervision_and_engineering (electric_operating_expenses_ferc1)

• depreciation_expense comes from Schedule 403 -> depreciation_expense in depreciation_amortization_summary_ferc1 where plant_function == common_plant_electric

• depreciation_expense_for_asset_retirement_costs comes from Schedule 403.1 -> depreciation_expense_asset_retirement in depreciation_amortization_summary_ferc1 (where plant_function == common_plant_electric only??)

• amortization_and_depletion_of_utility_plant comes from Schedule 404-5 -> ??

• amortization_of_electric_plant_acquisition_adjustments comes from Schedule 406 -> ??

• amortization_of_property_losses_unrecovered_plant_and_regulatory_study_costs comes from Schedule 407 -> ??

• amortization_of_conversion_expenses comes from Schedule 407 -> ??

• regulatory_debits comes from Schedule 407.3 -> ??

• regulatory_credits comes from Schedule 407.4 -> ??

[e-belfer]

@jrea-rmi Just circling back to this. Do you all have a working list of fields which are not identically named but are effectively identical and should be compared across tables? See above for some examples. We're particularly looking at 'second dimension' relationships (e.g. electric plants), but if there are others you're aware of this is also helpful to know!

[jrea-rmi]

@e-belfer I don't already have a compiled list like this, but I could review my previous table connections and see if I have additions to what you have.

A few balance sheet fields to add to your income statement notes are:

• regulatory assets (from assets side of balance sheet) is a detail table
• regulatory liabilities (from liabilities side of balance sheet) is a detail table
• several fields from utility plant section of balance sheet assets should match summary of utility plant fields
• electric plant in service and accumulated provision for depreciation, amortization... tables are components of the summary of utility plant table

[e-belfer]

Thanks for the follow-up and the suggestions! I'll work on compiling a list and push it to a PR for you to look over to see that nothing's missing or out-of-place.

[cmgosnell]

closing this issue bc we merged #2669 into explode_ferc1