INVESTMENT DEBT

Investment debt at March 31, 2014 and December 31, 2013 consist of the following:



(Dollars in millions)		Carrying Amount of Investment Debt as of ⁽¹⁾
Types of Property Pledged as Collateral	Region	March 31, 2014		December 31, 2013
Multifamily properties ⁽¹⁾	Western U.S.	$	260.2	$	261.0
Commercial buildings	Western U.S.	128.2		110.4
Residential	Western U.S	30.0		28.0
Commercial	Japan	2.4		2.4
Commercial⁽¹⁾	Ireland	75.2		—
Multifamily ⁽¹⁾	Ireland	202.8		—
Notes Receivable ⁽¹⁾	Ireland	82.5		—
Commercial ⁽¹⁾	United Kingdom	94.9		—
Notes Receivable ⁽¹⁾	United Kingdom	6.0		—
Investment debt⁽²⁾		$	882.2	$	401.8

⁽¹⁾The investment debt balances include the unamortized debt premiums. Debt premiums represent the excess of the fair value of debt over the principal value of debt assumed in various acquisitions and are amortized into interest expense over the remaining term of the related debt in a manner that approximates the effective interest method. The unamortized loan premium as of March 31, 2014 and December 31, 2013 was $12.9 million and $5.3 million, respectively.

⁽²⁾ The investment debt had a weighted average interest rate of 4.35% and 4.13% at March 31, 2014 and December 31, 2013.

During the three months ended March 31, 2014, seven mortgage loans secured by three apartment buildings and an office building in Ireland, and a retail center, office building, and loans in the United Kingdom were consolidated. See footnote 4 for further discussion. Additionally, during the three months ended March 31, 2014, the acquisition of a retail center in North Hollywood, CA, two apartment buildings in Ireland, and a note receivable in Ireland, were partially financed with mortgages. See note 4 for more detail on the acquisitions and the investment debt.

The aggregate maturities of investment debt subsequent to March 31, 2014 are as follows:



(Dollars in millions)
2014	$	26.9
2015	118.7
2016	51.8
2017	146.7
2018	86.7
Thereafter	438.5
	869.3
Debt premium	12.9
	$	882.2