Rate Matters	9 Months Ended
Sep. 30, 2016
Public Utilities, General Disclosures [Abstract]
Rate Matters	Rate Matters Except to the extent noted below, the circumstances set forth in Note 11 to the consolidated financial statements included in PSCo’s Annual Report on Form 10-K for the year ended Dec. 31, 2015 and in Note 5 to PSCo’s Quarterly Reports on Form 10-Q for the quarterly periods ended March 31, 2016 and June 30, 2016, appropriately represent, in all material respects, the current status of other rate matters, and are incorporated herein by reference. Pending Regulatory Proceeding — Colorado Public Utilities Commission (CPUC) Annual Electric Earnings Test — As part of an annual earnings test, PSCo must share with customers earnings that exceed the authorized return on equity (ROE) threshold of 9.83 percent for 2015 through 2017. The current estimate of the 2016 earnings test, based on annual forecasted information, did not result in the recognition of a liability as of Sept. 30, 2016.

Rate Matters

Except to the extent noted below, the circumstances set forth in Note 11 to the consolidated financial statements included in PSCo’s Annual Report on Form 10-K for the year ended Dec. 31, 2015 and in Note 5 to PSCo’s Quarterly Reports on Form 10-Q for the quarterly periods ended March 31, 2016 and June 30, 2016, appropriately represent, in all material respects, the current status of other rate matters, and are incorporated herein by reference.

Pending Regulatory Proceeding — Colorado Public Utilities Commission (CPUC)

Annual Electric Earnings Test — As part of an annual earnings test, PSCo must share with customers earnings that exceed the authorized return on equity (ROE) threshold of 9.83 percent for 2015 through 2017. The current estimate of the 2016 earnings test, based on annual forecasted information, did not result in the recognition of a liability as of Sept. 30, 2016.