Borrowings and Other Financing Instruments (Tables)

12 Months Ended

Dec. 31, 2019

Debt Disclosure [Abstract]

Money Pool [Table Text Block]

(Millions of Dollars, Except Interest Rates)	Three Months Ended Dec. 31, 2019			Year Ended Dec. 31
				2019			2018			2017
Borrowing limit	$	250		$	250		$	250		$	250
Amount outstanding at period end	—			—			—			85
Average amount outstanding	34			32			17			25
Maximum amount outstanding	119			250			143			142
Weighted average interest rate, computed on a daily basis	1.67		%	2.05		%	1.96		%	1.14		%
Weighted average interest rate at period end	N/A			N/A			N/A			1.18

Short Term Debt

Commercial paper outstanding for NSP-Minnesota was as follows:

(Millions of Dollars, Except Interest Rates)	Three Months Ended Dec. 31, 2019			Year Ended Dec. 31
				2019			2018			2017
Borrowing limit	$	500		$	500		$	500		$	500
Amount outstanding at period end	30			30			150			20
Average amount outstanding	2			71			38			62
Maximum amount outstanding	30			317			198			237
Weighted average interest rate, computed on a daily basis	2.05		%	2.59		%	2.08		%	1.10		%
Weighted average interest rate at end of period	2.05			2.05			2.97			1.93

Schedule of Debt To Total Capitalization Ratio

Features of NSP-Minnesota’s credit facility:

Debt-to-Total Capitalization Ratio (a)				Amount Facility May Be Increased (millions)		Additional Periods for Which a One-Year Extension May Be Requested (b)
2019		2018
48	%	48	%	$	100	2

^(a)  The credit facility has a financial covenant requiring that the debt-to-total capitalization ratio be less than or equal to 65%.

^(b) 

All extension requests are subject to majority bank group approval

Credit Facilities

Dec. 31, 2019 (in millions):

Credit Facility (a)		Drawn (b)		Available
$	500	$	40	$	460

^(a)  This credit facility matures in June 2024 .

^(b)  Includes outstanding commercial paper and letters of credit.

Schedule of Long-Term Debt

Long term debt obligations for NSP-Minnesota as of Dec. 31 (millions of dollars):

Financing Instrument	Interest Rate		Maturity Date	2019			2018
First mortgage bonds	2.20	%	Aug. 15, 2020	$	300		$	300
First mortgage bonds	2.15	%	Aug. 15, 2022	300			300
First mortgage bonds	2.60	%	May 15, 2023	400			400
First mortgage bonds	7.13	%	July 1, 2025	250			250
First mortgage bonds	6.50	%	March 1, 2028	150			150
First mortgage bonds	5.25	%	July 15, 2035	250			250
First mortgage bonds	6.25	%	June 1, 2036	400			400
First mortgage bonds	6.20	%	July 1, 2037	350			350
First mortgage bonds	5.35	%	Nov. 1, 2039	300			300
First mortgage bonds	4.85	%	Aug. 15, 2040	250			250
First mortgage bonds	3.40	%	Aug. 15, 2042	500			500
First mortgage bonds	4.13	%	May 15, 2044	300			300
First mortgage bonds	4.00	%	Aug. 15, 2045	300			300
First mortgage bonds	3.60	%	May 15, 2046	350			350
First mortgage bonds	3.60	%	Sept. 15, 2047	600			600
First mortgage bonds (a)	2.90	%	March 1, 2050	600			—
Unamortized discount				(31		)	(21		)
Unamortized debt issuance cost				(48		)	(42		)
Current maturities				(300		)	—
Total long-term debt				$	5,221		$	4,937

^(a) 

2019 financing

Schedule of Maturities of Long-term Debt

Maturities of long-term debt are as follows:

(Millions of Dollars)
2020	$	300
2021	—
2022	300
2023	400
2024	—

Dividend Payment Restrictions

Requirements and actuals as of Dec. 31, 2019:

Equity to Total Capitalization Ratio - Required Range				Equity to Total Capitalization Ratio - Actual
Low		High		2019
47.1	%	57.5	%	52.3	%

Unrestricted Retained Earnings			Total Capitalization			Limit on Total Capitalization
$	1.1	billion	$	11.6	billion	$	12.7	billion