Loans Receivable and Allowance for Credit Losses (Amortized Cost of Loans on Nonaccrual Status) (Details) $ in Thousands	Sep. 30, 2020 USD ($)
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	$ 169,528
Commercial lending
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	152,684
Commercial lending | Commercial and industrial (“C&I”)
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	95,475
Commercial lending | Commercial real estate (“CRE”)
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	54,659
Commercial lending | Total CRE
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	57,209
Consumer lending
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	16,844
Consumer lending | HELOCs
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	8,339
Consumer lending | Total residential mortgage
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	14,353
Consumer lending | Other consumer
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	2,491
Single-family residential | Consumer lending | Real estate loan
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	6,014
Multifamily residential | Commercial lending | Real estate loan
Financing Receivable, Nonaccrual [Line Items]
Total nonaccrual loans with no related allowance for loan losses	$ 2,550