Regulatory Accounting: Rate Review (Details) $ in Millions	Feb. 01, 2019 USD ($)	Mar. 29, 2019 utility	Mar. 06, 2019 utility
Application Filed | Nebraska Public Service Commission (NPSC) | Black Hills Energy, Nebraska Gas
Public Utilities, General Disclosures [Line Items]
Public Utilities, Number of Companies Being Merged		2
Application Filed | Wyoming Public Service Commission (WPSC) | Black Hills Energy, Wyoming Gas
Public Utilities, General Disclosures [Line Items]
Public Utilities, Number of Companies Being Merged			4
Rate Review Filed with the Regulatory Agency | Colorado Public Utilities Commission (CPUC) | Black Hills Energy, Colorado Gas
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase, Amount | $	$ 2.5