Mortgage Servicing Rights - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Servicing Asset at Amortized Cost [Line Items]
Mortgage Loans Serviced By For Third Parties	$ 4,400,000			$ 4,400,000		$ 4,700,000
Fair value of MSRs	29,500			29,500		28,200
Residential Mortgage
Servicing Asset at Amortized Cost [Line Items]
Reduction (addition) to valuation allowance	2,200	$ (6,100)	$ 6,600	(3,900)	$ 7,700
Valuation Allowance for Impairment of Recognized Servicing Assets, Balance	$ 6,600	$ 4,400	$ 7,700	$ 6,600	$ 7,700	$ 10,500	$ 1,100	$ 0