Loans Receivable and Allowance for Credit Losses (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Nonaccrual loans
Financing receivable, nonaccrual	$ 215,154
Loans in process of foreclosure
Foreclosed assets	19,700	$ 1,300
Commercial Lending
Nonaccrual loans
Financing receivable, nonaccrual	184,153
Consumer Lending
Nonaccrual loans
Financing receivable, nonaccrual	31,001
Residential real estate properties
Loans in process of foreclosure
Recorded investment in consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process	$ 4,100	7,200
PCI Loans
Nonaccrual loans
Financing receivable, nonaccrual		$ 297