Share-Based Compensation, Share-Based Compensation Expense (Details) - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Matching contributions related to 401(k) plan				$ 7,400
Share-Based Compensation Expense [Abstract]
Granted (in shares)		522	496	588
Compensation cost for share-based awards	[1],[2]	$ 41,170	$ 44,928	$ 32,189
Tax benefit recognized in income		16,005	17,570	12,557
Capitalized compensation cost for share-based awards	[3]	0	0	$ 1,887
Unrecognized compensation cost related to nonvested share-based compensation awards		$ 29,000	$ 36,400
Weighted-average period for recognition of unrecognized compensation cost related to nonvested share-based compensation awards (in years)		1 year 7 months
Award Vesting Period (in years)		3 years
Xcel Energy Inc. 2015 Omnibus Incentive Plan [Member]
Share-Based Compensation Expense [Abstract]
Number of shares of common stock approved for issuance (in shares)		7,000
Xcel Energy Inc. Long-Term Incentive Plan [Member]
Share-Based Compensation Expense [Abstract]
Number of shares of common stock approved for issuance (in shares)		8,300
Xcel Energy Inc. Executive Annual Incentive Award Plan [Member]
Share-Based Compensation Expense [Abstract]
Number of shares of common stock approved for issuance (in shares)		1,200
Service-based awards [Member]
Share-Based Compensation Expense [Abstract]
Granted (in shares)		300	300	400

[1] Compensation costs for share-based payment arrangements are included in O&M expense in the consolidated statements of income.

[2] Included in compensation cost for share-based awards are matching contributions related to the Xcel Energy 401(k) plan, which totaled $7.4 million for 2014. In October 2013, Xcel Energy determined that it would settle the 401(k) employer match in cash instead of common stock going forward for all employee groups except PSCo bargaining employees. Share-based compensation accounting for the impacted employee groups ceased in October 2013, and corresponding expense amounts recorded to equity were reclassified to a liability for expected cash settlements. In August 2015, consistent with a new PSCo bargaining agreement, share-based compensation accounting ceased for the employer 401(k) match for PSCo bargaining employees, which will be paid in cash. As a result, 2015 and 2016 compensation cost for share-based awards includes no 401(k) matching contributions.

[3] An allocated amount of the 401(k) match is capitalized.