ALLOWANCE FOR LOAN LOSSES

As discussed in Note 1, the Company estimates for currently existing and probable losses for its mortgage loans that are considered impaired. A loan can be considered impaired even if it is not delinquent. The following table summarizes the aggregate activity for the portion of the allowance for loan losses that relates to the securitized mortgage loan portfolio for the periods indicated:



	Three Months Ended
	March 31,
	2013						2012
	Commercial			Single-family			Commercial			Single-family
Allowance at beginning of period	$	150		$	289		$	2,268		$	231
Provision for loan losses	—			261			60			—
Credit losses, net of recoveries	(5		)	(435		)	(987		)	—
Allowance at end of period	$	145		$	115		$	1,341		$	231

The following table summarizes information regarding the Company's impaired securitized commercial and single-family mortgage loans as of March 31, 2013 and December 31, 2012:



	March 31, 2013				March 31, 2012
	Commercial		Single-family		Commercial		Single-family
Unpaid principal balance of impaired securitized loans	$	—	$	4,171	$	1,814	$	3,029
Basis adjustments related to impaired securitized loans	—		62		—		59
Amortized cost basis of impaired securitized loans	$	—	$	4,233	$	1,814	$	3,088

For the securitized single-family mortgage loans identified as impaired as of March 31, 2013, the Company estimates that it has recognized approximately $61 of interest income for the three months ended March 31, 2013 compared to $40 for the three months ended March 31, 2012 for the securitized single-family mortgage loans identified as impaired as of March 31, 2012. Although the Company did not have any specific securitized commercial mortgage loans identified as impaired as of March 31, 2013, it is currently maintaining a general allowance for commercial mortgage loan losses of $145. The Company recognized $0 of interest income on impaired commercial securitized mortgage loans for the three months ended March 31, 2013compared to an estimate of $25 for the three months ended March 31, 2012 for the securitized commercial mortgage loans identified as impaired as of March 31, 2012.