Mortgage Servicing Assets (Tables)

12 Months Ended

Dec. 31, 2017

Mortgage Banking [Abstract]

Summary of Mortgage Servicing Rights

A summary of mortgage servicing rights follows:

	2017			2016			2015
	(dollars in thousands)
Beginning of year mortgage servicing rights:	$	2,271		$	2,040		$	2,072
Amounts capitalized		587			982			657
Amortization		(733	)		(751	)		(689	)
Impairment		—			—			—
End of year	$	2,125		$	2,271		$	2,040

Estimated Amortization Expense

Amortization expense is estimated as follows:

Year ending December 31,
(dollars in thousands)
2018	$	501
2019		434
2020		367
2021		300
2022		232
Thereafter		291
Total	$	2,125

Key Assumptions Used to Value Mortgage Servicing Rights

The key assumptions used to value mortgage servicing rights were as follows:

	2017			2016
Weighted average remaining life	264 months			262 months
Weighted average discount rate		13	%		14	%
Weighted average coupon		3.94	%		3.89	%
Weighted average prepayment speed		150	%		145	%