The Company periodically sells or securitizes mortgage loans while retaining the obligation to perform the servicing of such loans. In addition, the Company may purchase or assume the right to service mortgage loans originated by others. Whenever the Company undertakes an obligation to service a loan, management assesses whether a servicing asset and/or liability should be recognized. A servicing asset is recognized whenever the compensation for servicing is expected to more than adequately compensate the Company for servicing the loans and leases. Likewise, a servicing liability would be recognized in the event that servicing fees to be received are not expected to adequately compensate the Company for its expected cost.

All separately recognized servicing assets are recognized at fair value using the fair value measurement method. Under the fair value measurement method, the Company measures servicing rights at fair value at each reporting date, reports changes in fair value of servicing assets in earnings in the period in which the changes occur, and includes these changes, if any, with mortgage banking activities in the consolidated statements of operations. The fair value of servicing rights is subject to fluctuations as a result of changes in estimated and actual prepayment speeds and default rates and losses.

The fair value of servicing rights is estimated by using a cash flow valuation model which calculates the present value of estimated future net servicing cash flows, taking into consideration actual and expected loan prepayment rates, discount rates, servicing costs, and other economic factors, which are determined based on current market conditions.

At December 31, 2014, servicing assets amounted to $14.0 million, related to residential mortgage loans. At December 31, 2013, servicing assets was composed of $13.8 million related to residential mortgage loans and $22 thousand of leasing servicing assets acquired in the FDIC-assisted acquisition of Eurobank.

The following table presents the changes in servicing rights measured using the fair value method for the years ended December 31, 2014, 2013 and 2012:

		Year Ended December 31,
		2014	2013		2012
		(In thousands)
Fair value at beginning of year	$	13,801	$	10,795	$	10,454
Servicing from mortgage securitizations or asset transfers		2,149		3,177		1,867
Changes due to payments on loans		(1,072)		(950)		(1,107)
Changes in fair value due to changes in valuation model inputs or assumptions		(886)		779		(419)
Fair value at end of year	$	13,992	$	13,801	$	10,795

The following table presents key economic assumption ranges used in measuring the mortgage-related servicing asset value for the years ended December 31, 2014, 2013 and 2012:

	Year Ended December 31,
	2014	2013	2012
Constant prepayment rate	4.16% - 13.98%	5.78% - 14.33%	8.51% - 16.29%
Discount rate	10.00% - 12.00%	10.00% - 12.00%	10.50% - 13.50%

The sensitivity of the current fair value of servicing assets to immediate 10 percent and 20 percent adverse changes in the above key assumptions were as follows:

	December 31, 2014
	(In thousands)
Mortgage-related servicing asset
Carrying value of mortgage servicing asset	$	13,992
Constant prepayment rate
Decrease in fair value due to 10% adverse change	$	(414)
Decrease in fair value due to 20% adverse change	$	(807)
Discount rate
Decrease in fair value due to 10% adverse change	$	(643)
Decrease in fair value due to 20% adverse change	$	(1,234)

These sensitivities are hypothetical and should be used with caution. As the figures indicate, changes in fair value based on a 10 percent variation in assumptions generally cannot be extrapolated because the relationship of the change in assumption to the change in fair value may not be linear. Also, in this table, the effect of a variation in a particular assumption on the fair value of the retained interest is calculated without changing any other assumption.

Changes in one factor may result in changes in another (for example, increases in market interest rates may result in lower prepayments), which may magnify or offset the sensitivities. Mortgage banking activities, a component of total banking and financial service revenue in the consolidated statements of operations, include the changes from period to period in the fair value of the mortgage loan servicing rights, which may result from changes in the valuation model inputs or assumptions (principally reflecting changes in discount rates and prepayment speed assumptions) and other changes, including changes due to collection/realization of expected cash flows.

Servicing fee income is based on a contractual percentage of the outstanding principal and is recorded as income when earned. Servicing fees on mortgage loans totaled $6.3 million in 2014, $5.5 million in 2013, and $3.6 million in 2012. There were no late fees and ancillary fees recorded in such years because these fees belong to the third party engaged by the Company pursuant to a subservicing agreement. Servicing fees on leases amounted to $10 thousand in 2014, $68 thousand in 2013 and $239 thousand in 2012.