Note 5 — Capitalized Mortgage Servicing Rights

Our capitalized mortgage servicing rights (“MSRs”) reflect commercial real estate MSRs derived from loans sold in our Agency Business. The discount rates used to determine the present value of our MSRs throughout the periods presented for all MSRs were between 8% - 15% (representing a weighted average discount rate of 12%) based on our best estimate of market discount rates. The weighted average estimated life remaining of our MSRs was 7.2 years at both March 31, 2018 and December 31, 2017.

A summary of our capitalized MSR activity is as follows (in thousands):

	Three Months Ended March 31, 2018
	Acquired			Originated			Total
Balance at beginning of period	$	143,270		$	109,338		$	252,608
Additions	—			19,800			19,800
Amortization	(7,995		)	(3,870		)	(11,865		)
Write-downs and payoffs	(3,341		)	(1,470		)	(4,811		)

Balance at end of period	$	131,934		$	123,798		$	255,732

	Three Months Ended March 31, 2017
Balance at beginning of period	$	194,801		$	32,942		$	227,743
Additions	—			26,469			26,469
Amortization	(10,462		)	(1,426		)	(11,888		)
Write-downs and payoffs	(3,393		)	—			(3,393		)

Balance at end of period	$	180,946		$	57,985		$	238,931

We collected prepayment fees of $3.7 million and $2.0 million during the three months ended March 31, 2018 and 2017, respectively, which are included as a component of servicing revenue, net on the consolidated statements of income. As of March 31, 2018 and December 31, 2017, we had no valuation allowance recorded on any of our MSRs.

The expected amortization of capitalized MSRs recorded as of March 31, 2018 is shown in the table below. Actual amortization may vary from these estimates (in thousands).

Year	Amortization
2018 (nine months ending 12/31/2018)	$	35,767
2019	44,539
2020	39,231
2021	31,900
2022	25,314
2023	20,802
Thereafter	58,179

Total	$	255,732