Unsecured Revolving Line of Credit

12 Months Ended

Dec. 31, 2019

Line of Credit Facility [Abstract]

Debt Disclosure

(10)          Unsecured Revolving Line of Credit

Unsecured Revolving Line of Credit

We have a $400 million revolving credit facility, which matures December 12, 2021. The facility includes an accordion feature that allows us to increase the size to $450 million with the consent of the lenders. The facility does not amortize and is unsecured. The facility bears interest at the lower of prime plus a credit spread, ranging from 0% to 0.75%, or available rates tied to the Eurodollar rate plus a credit spread, ranging from 0.88% to 1.75%. A total of eight banks participate in the facility, with no one bank providing more than 16% of the total availability. In addition, on March 27, 2018, we entered into a $25 million revolving credit facility, maturing March 27, 2021, to provide swingline borrowing capability. The $25 million revolving credit facility bears interest at the lower of prime plus a credit spread of 0.13%, or available rates tied to the Eurodollar rate plus a credit spread of 0.65%. Commitment fees for the unsecured revolving lines of credit were $0.3 million and $0.4 million for the years ended December 31, 2019 and 2018.

The availability under the facilities in place for the years ended December 31 is shown in the following table (in millions):

	2019		2018
Unsecured revolving line of credit, expiring December 2021	$	400.0	$	400.0
Unsecured revolving line of credit, expiring March 2021	25.0		25.0
	425.0		425.0
Amounts outstanding at December 31:
Eurodollar borrowings	289.0		308.0
Letters of credit	—		0.2
	289.0		308.2
Net availability as of December 31	$	136.0	$	116.8

Our covenants require us to meet certain financial tests, including a maximum debt to capitalization ratio not to exceed 65%. In addition, there are covenants which, among other things, limit our ability to engage in any consolidation or merger or otherwise liquidate or dissolve, dispose of property, and enter into transactions with affiliates. A default on the South Dakota or Montana First Mortgage Bonds would trigger a cross default on the credit facility; however a default on the credit facilities would not trigger a default on any other obligations.