Fair Value Measurements - Fair Value of Assets Measured on Nonrecurring Basis (Details) - Nonrecurring - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 27,348	$ 21,686
OREO	2,820	4,319
Mortgage servicing rights	53,208
Total financial assets	83,376	26,005
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
OREO	0	0
Mortgage servicing rights	0
Total financial assets	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
OREO	0	0
Mortgage servicing rights	0
Total financial assets	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	27,348	21,686
OREO	2,820	4,319
Mortgage servicing rights	53,208
Total financial assets	$ 83,376	$ 26,005