Fair Value Measurements - Assets Measured at Fair Value on a Nonrecurring Basis (Details) - Fair Value, measurements, nonrecurring - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Impaired loans measured at fair value on a nonrecurring basis
Individually evaluated loans, net of allowance for credit losses	$ 11,150	$ 24,145
OREO	549	2,736
Mortgage servicing rights	84,912	62,994
Total financial assets	96,611	89,875
Level 1
Impaired loans measured at fair value on a nonrecurring basis
Individually evaluated loans, net of allowance for credit losses	0	0
OREO	0	0
Mortgage servicing rights	0	0
Total financial assets	0	0
Level 2
Impaired loans measured at fair value on a nonrecurring basis
Individually evaluated loans, net of allowance for credit losses	0	0
OREO	0	0
Mortgage servicing rights	0	0
Total financial assets	0	0
Level 3
Impaired loans measured at fair value on a nonrecurring basis
Individually evaluated loans, net of allowance for credit losses	11,150	24,145
OREO	549	2,736
Mortgage servicing rights	84,912	62,994
Total financial assets	$ 96,611	$ 89,875