Schedule I, Condensed Financial Statements of Xcel Energy Inc, Condensed Statements of Income (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income
Equity earnings of subsidiaries									$ 42,123	$ 34,390	$ 30,151
Expenses and other deductions
Other income									(7,950)	(5,400)	(5,296)
Interest charges and financing costs									646,907	595,282	566,608
Income before income taxes									1,704,596	1,527,204	1,545,121
Income tax benefit									581,217	542,719	523,815
Net income	$ 227,477	$ 457,795	$ 196,795	$ 241,312	$ 209,025	$ 426,463	$ 196,931	$ 152,066	1,123,379	984,485	1,021,306
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension and retiree medical benefits, net of tax of $(2,759), $(2,777), and $(2,528) respectively									(7,783)	(7,906)	(7,517)
Comprehensive Income, Net of Tax									$ 1,122,778	$ 982,871	$ 1,019,442
Weighted average common shares outstanding:
Basic (in shares)									508,794	507,768	503,847
Diluted (in shares)									509,465	508,168	504,117
Earnings per average common share:
Basic (in dollars per share)	$ 0.45	$ 0.90	$ 0.39	$ 0.47	$ 0.41	$ 0.84	$ 0.39	$ 0.30	$ 2.21	$ 1.94	$ 2.03
Diluted (in dollars per share)	0.45	0.90	0.39	0.47	0.41	0.84	0.39	0.30	2.21	1.94	2.03
Cash dividends declared per common share (in dollars per share)	$ 0.34	$ 0.34	$ 0.34	$ 0.34	$ 0.32	$ 0.32	$ 0.32	$ 0.32	$ 1.36	$ 1.28	$ 1.20
Xcel Energy Inc.
Income
Equity earnings of subsidiaries									$ 1,198,556	$ 1,045,788	$ 1,077,714
Total income									1,198,556	1,045,788	1,077,714
Expenses and other deductions
Operating expenses									22,128	19,865	19,756
Other income									(3,047)	(1,242)	(537)
Interest charges and financing costs									115,473	91,801	84,830
Total expenses and other deductions									134,554	110,424	104,049
Income before income taxes									1,064,002	935,364	973,665
Income tax benefit									(59,377)	(49,121)	(47,641)
Net income									1,123,379	984,485	1,021,306
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Pension and retiree medical benefits, net of tax of $(2,759), $(2,777), and $(2,528) respectively									(4,312)	(4,380)	(4,022)
Derivative instruments, net of tax of $2,344, $1,764, and $1,390, respectively									3,711	2,766	2,125
Other, net of tax of $0, $0 and $21, respectively									0	0	33
Other Comprehensive Income (Loss), Net of Tax									(601)	(1,614)	(1,864)
Comprehensive Income, Net of Tax									$ 1,122,778	$ 982,871	$ 1,019,442