9. Notes Payable

The following is a summary of our indebtedness:



(in millions)	March 31, 2019		December 31, 2018
Commercial banks
Term Loan, due 2022	$	99.6	$	99.6
Unsecured credit facility	242.0		—
	$	341.6	$	99.6

Senior unsecured notes (1)
4.78% Notes, due 2021	$	249.2	$	249.1
3.15% Notes, due 2022	347.4		347.3
5.07% Notes, due 2023	248.1		248.0
4.36% Notes, due 2024	248.8		248.7
3.68% Notes, due 2024	247.7		247.6
3.74% Notes, due 2028	396.3		396.1
	$	1,737.5	$	1,736.8

Total unsecured notes payable	$	2,079.1	$	1,836.4

Secured notes (1)
4.38% Conventional Mortgage Loan, due 2045	$	45.7	$	45.9
5.19% Conventional Mortgage Notes, due 2019	—		419.9
5.33% Conventional Mortgage Loan, due 2019	—		19.4
Total secured notes payable	$	45.7	$	485.2

Total notes payable	$	2,124.8	$	2,321.6

Other floating rate debt included in unsecured notes (3.33%)	$	341.6	$	99.6


(1)	Unamortized debt discounts and debt issuance costs of $13.1 million and $13.9 million are included in senior unsecured and secured notes payable as of March 31, 2019 and December 31, 2018, respectively.

In March 2019, we amended and restated our $600 million unsecured credit facility extending the maturity date from August 2019 to March 2023, with two options to further extend the facility at our election for two additional six month periods, and increasing the facility from $600 million to $900 million, which may be expanded three times by up to an additional $500 million upon satisfaction of certain conditions. The interest rate on our unsecured credit facility is based upon the London Interbank Offered Rate ("LIBOR") plus a margin which is subject to change as our credit ratings change. Advances under our credit facility may be priced at the scheduled rates, or we may enter into bid rate loans with participating banks at rates below the scheduled rates. These bid rate loans have terms of 180 days or less and may not exceed the lesser of $450 million or the remaining amount available under our credit facility. Our credit facility is subject to customary financial covenants and limitations. We believe we are in compliance with all such financial covenants and limitations on the date of this filing.

Our credit facility provides us with the ability to issue up to $50 million in letters of credit. While our issuance of letters of credit does not increase our borrowings outstanding under our credit facility, it does reduce the amount available. At March 31, 2019, we had approximately $242.0 million amounts outstanding on our $900 million credit facility and we had outstanding letters of credit totaling approximately $10.1 million, leaving approximately $647.9 million available under our credit facility.

We have a $45.0 million unsecured short-term borrowing facility which matures in May 2019. The interest rate is based on LIBOR plus 0.95%. At March 31, 2019, we had no balance outstanding, leaving $45.0 million available under this facility.

During the three months ended March 31, 2019, we repaid approximately $439.3 million of secured conventional mortgage debt utilizing our unsecured credit facility and proceeds from our equity offering completed in February 2019.

We had outstanding floating rate debt of approximately $341.6 million and $175.0 million at March 31, 2019 and 2018, respectively, which includes our unsecured credit facility. The weighted average interest rate on such debt was approximately 3.3% and 2.2% for the three months ended March 31, 2019 and 2018, respectively.

Our indebtedness, which includes our unsecured credit facility, had a weighted average maturity of approximately 5.6 years at March 31, 2019. The table below is a summary of the maturity dates of our outstanding debt and principal amortizations, and the weighted average interest rates on such debt, at March 31, 2019:



(in millions) (1)	Amount			Weighted Average Interest Rate
2019	$	(1.5	)	—	%
2020	(1.9		)	—
2021	248.5			4.8
2022	448.8			3.2
2023	249.8			5.1
Thereafter (2)	1,181.1			3.8
Total	$	2,124.8		3.9	%


(1)	Includes amortization of debt discounts, debt issuance costs, net of scheduled principal payments, and all available extension options.


(2)	Includes $242.0 million outstanding on our unsecured credit facility.