Short-Term Borrowings and Credit Arrangements

12 Months Ended

Dec. 31, 2014

Short-term Debt [Abstract]

Short-Term Debt

Short-Term Borrowings and Credit Arrangements

Short-Term Borrowings

Short-term borrowings and the corresponding weighted average interest rates as of December 31 were as follows (dollars in millions, except for percentages):

	2014				2013
Short-Term Debt	Balance		Interest Rate		Balance		Interest Rate
Commercial Paper	$	267.8	0.50	%	$	141.0	0.41	%

The following information relates to commercial paper for the years ended December 31 (dollars in millions):

	2014			2013
Maximum short-term debt outstanding	$	276.9		$	199.9
Average short-term debt outstanding	$	132.5		$	69.0
Weighted-average interest rate	0.39		%	0.40		%

In the fourth quarter of 2014, we increased the size of our commercial paper program from $250 million to $340 million. Under the program we may issue unsecured commercial paper notes on a private placement basis to provide an additional financing source for our short-term liquidity needs. The maturities of the commercial paper issuances will vary, but may not exceed 270 days from the date of issue. Commercial paper issuances are supported by available capacity under our unsecured revolving credit facility.

Unsecured Revolving Line of Credit

In the fourth quarter of 2014, we exercised the accordion feature under our $300 million unsecured revolving credit facility to increase the size to $350 million. The facility does not amortize and is scheduled to expire on November 5, 2018. The facility bears interest at the Eurodollar rate plus a credit spread, ranging from 0.88% to 1.75%, or a base rate, plus a margin of 0.0% to 0.75%. A total of eight banks participate in the facility, with no one bank providing more than 21% of the total availability. There were no direct borrowings or letters of credit outstanding as of December 31, 2014. Commitment fees for the unsecured revolving line of credit were $0.4 million and $0.5 million for the years ended December 31, 2014 and 2013, respectively.

The credit facility includes covenants that require us to meet certain financial tests, including a maximum debt to capitalization ratio not to exceed 65%. The facility also contains 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 facility would not trigger a default on any other obligations.

Bridge Facility

In November 2013, in connection with the Hydro Transaction, we entered into a $900 million364-day senior bridge credit facility. The bridge facility was not drawn upon and cancelled in November 2014.