Mortgage Servicing Rights - Loans, Fees, Amortization and Carrying Value (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Other Intangible Assets
Unpaid principal amount of consumer loans serviced for others	$ 2,400,000		$ 2,300,000
Contractually specified fees, late charges, and ancillary fees	1,500	$ 1,600
Amortization of mortgage servicing rights	1,980	764
MSRs
Other Intangible Assets
Amortization of mortgage servicing rights	2,000	$ 800
Estimated future amortization expenses for MSRs, next five years
Under one year	2,535
2021	2,047
2022	1,651
2023	1,341
2024	1,101
Details of MSRs
Gross carrying amount	64,771		63,480
Less: accumulated amortization	52,792		50,812
Net carrying value	$ 11,979		$ 12,668

Principal amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

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Amount of contractually specified servicing fee, late fee, and ancillary fee recognized as income for servicing asset and servicing liability.

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of amortization of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

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