The following table presents a composition of total income from servicing rights, which is reported in Loan Servicing Income on the Consolidated Statements of Operations for the periods indicated:



	Year Ended December 31,
($ in thousands)	2019			2018			2017
Servicing fees for sold loans with servicing retained	$	1,291		$	5,048		$	19,642
Losses on the fair value and amortization of servicing rights	(612		)	(1,328		)	(17,066		)
Total income from servicing rights⁽¹⁾	$	679		$	3,720		$	2,576

The following table presents a composition of servicing rights as of the dates indicated:



	December 31,
($ in thousands)	2019		2018
Mortgage servicing rights, at fair value	$	1,157	$	1,770
SBA servicing rights, at cost	1,142		1,658
Total	$	2,299	$	3,428

Mortgage loans sold with servicing retained are subserviced by a third party vendor. The unpaid principal balance of these loans at December 31, 2019 and 2018 was $150.6 million and $204.0 million and are not reported as assets. Custodial escrow balances maintained in connection with serviced loans were $198 thousand and $300 thousand at December 31, 2019 and 2018. The unpaid principal balance of the loans underlying our SBA servicing rights at December 31, 2019 and 2018 was $75.2 million and $96.4 million.

The value of retained MSRs is generally estimated based on a valuation from a third party provider that calculates the present

value of the expected net servicing income from the portfolio based on key factors that include interest rates, prepayment assumptions, discount rate and estimated cash flows. The following table presents the key characteristics, inputs and economic



	December 31,
($ in thousands)	2019			2018
Fair value of retained MSRs	$	1,157		$	1,704
Discount rate	13.00		%	13.00		%
Constant prepayment rate	18.96		%	17.21		%
Weighted-average life (in years)	4.41			4.93

The following table presents activity in the MSRs for the periods indicated:



	Year Ended December 31,
($ in thousands)	2019			2018			2017
Balance at beginning of year	$	1,770		$	31,852		$	76,121
Additions	—			—			12,127
Changes in fair value resulting from valuation inputs or assumptions	(265		)	(1,155		)	(10,240		)
Sales of servicing rights ⁽¹⁾	—			(28,549		)	(39,345		)
Other—loans paid off	(348		)	(378		)	(6,811		)
Balance at end of year	$	1,157		$	1,770		$	31,852

(1) Includes $37.8 million of MSRs sold as a part of discontinued operations for the year ended December 31, 2017.

During the first half of 2018, we sold $28.5 million of MSRs on approximately $3.55 billion in unpaid principal

balances of conventional agency mortgage loans for cash consideration of $30.1 million, subject to a prepayment protection

provision and standard representations and warranties. The sale of MSRs resulted in a net loss of $2.3 million for the year ended December 31, 2018, primarily related to transaction costs, provision for early repayments of loans, and expected repurchase obligations under standard representations and warranties.

The value of SBA servicing rights is estimated based on a present value of the expected net servicing income from the portfolio based on key factors that include interest rates, prepayment assumptions, discount rate and estimated cash flows. The following table presents the key characteristics, inputs and economic assumptions used to estimate the fair value of the SBA servicing rights as of the dates indicated:



	December 31,
($ in thousands)	2019			2018
Servicing rights	$	1,142		$	1,658
Discount rate	8.75		%	9.50		%
Constant prepayment rate	8.00		%	8.00		%
Weighted-average life (in years)	3.75			4.29

The following table presents activity in the SBA servicing rights for the periods indicated:



	Year Ended December 31,
($ in thousands)	2019			2018			2017
Balance at beginning of year	$	1,658		$	1,856		$	1,496
Additions	—			127			761
Amortization, including prepayments	(493		)	(298		)	(318		)
Impairment	(23		)	(27		)	(83		)
Balance at end of year	$	1,142		$	1,658		$	1,856