Mortgage Servicing Rights Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Servicing Assets at Amortized Value [Line Items]
Loans serviced by unrelated third party	$ 4,300,000	$ 4,700,000
Estimated fair value of MSRs	35,400	28,200
Non-interest income before investment securities gains	240,229	226,335	$ 211,427
Mortgage banking
Servicing Assets at Amortized Value [Line Items]
Non-interest income before investment securities gains	33,576	42,309	23,099
Residential mortgage
Servicing Assets at Amortized Value [Line Items]
Estimated fair value of MSRs	35,393	28,245	45,193
Increase to valuation allowance	600	10,500	0	$ 0
Amortization expense	11,968	12,695	6,852
Residential mortgage | Mortgage banking
Servicing Assets at Amortized Value [Line Items]
Non-interest income before investment securities gains	$ 11,200	$ 11,900	$ 12,000