Schedule I, Condensed Financial Statements of Xcel Energy Inc, Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating activities
Net cash provided by (used in) operating activities	$ 3,052,299	$ 3,037,863	$ 2,659,486
Investing activities
Payments for (Proceeds from) Other Investing Activities	789	(145)	(3,695)
Net cash provided by (used in) investing activities	(3,261,413)	(3,622,774)	(3,117,251)
Financing activities
Proceeds from (repayment of) short-term borrowings, net	(454,000)	(173,500)	260,500
Proceeds from issuance of long-term debt	2,423,768	1,626,212	837,584
Repayment of long-term debt	(1,035,901)	(250,882)	(275,948)
Proceeds from issuance of common stock	0	7,011	180,798
Repurchase of common stock	32,209	0	0
Dividends paid	(680,521)	(606,574)	(561,411)
Other	(12,487)	(12,024)	(11,294)
Net cash provided by (used in) financing activities	208,650	590,243	430,229
Net change in cash and cash equivalents	(464)	5,332	(27,536)
Cash and cash equivalents at beginning of period	84,940	79,608	107,144
Cash and cash equivalents at end of period	84,476	84,940	79,608
Xcel Energy Inc.
Operating activities
Net cash provided by (used in) operating activities	816,717	704,823	842,832
Investing activities
Capital contributions to subsidiaries	(414,246)	(820,382)	(422,459)
Investments in the utility money pool	(1,879,500)	(971,200)	(1,148,000)
Return of investments in the utility money pool	1,879,500	987,200	1,204,000
Payments for (Proceeds from) Other Investing Activities	0	(16)	0
Net cash provided by (used in) investing activities	(414,246)	(804,398)	(366,459)
Financing activities
Proceeds from (repayment of) short-term borrowings, net	(516,000)	203,500	(95,500)
Proceeds from issuance of long-term debt	1,538,762	495,449	0
Repayment of long-term debt	(703,979)	0	0
Proceeds from issuance of common stock	0	7,011	180,798
Repurchase of common stock	(32,209)	0	0
Dividends paid	(680,521)	(606,574)	(561,411)
Other	(8,690)	0	0
Net cash provided by (used in) financing activities	(402,637)	99,386	(476,113)
Net change in cash and cash equivalents	(166)	(189)	260
Cash and cash equivalents at beginning of period	517	706	446
Cash and cash equivalents at end of period	$ 351	$ 517	$ 706