Loans Receivable and Allowance for Credit Losses (TDR Post-Modifications) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	$ 28,229	$ 58,036	$ 47,072	$ 102,181
Commitment to lend	6,800		6,800		$ 3,000
Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	28,229	41,493	29,898	58,511
Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	10,819
Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	16,543	0	32,851
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	17,174	0
Commercial lending
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	28,229	58,036	47,072	102,181
Commercial lending | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	28,229	41,493	29,898	58,511
Commercial lending | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	10,819
Commercial lending | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	16,543	0	32,851
Commercial lending | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0
Commercial lending | Commercial and industrial (“C&I”)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	27,111	35,568	45,954	79,713
Commercial lending | Commercial and industrial (“C&I”) | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	27,111	19,025	28,780	36,043
Commercial lending | Commercial and industrial (“C&I”) | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	10,819
Commercial lending | Commercial and industrial (“C&I”) | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	16,543	0	32,851
Commercial lending | Commercial and industrial (“C&I”) | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	17,174	0
Commercial lending | Commercial real estate (“CRE”)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	21,242	0	21,242
Commercial lending | Commercial real estate (“CRE”) | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	21,242	0	21,242
Commercial lending | Commercial real estate (“CRE”) | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Commercial real estate (“CRE”) | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Commercial real estate (“CRE”) | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Real estate loan | Multifamily residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,118	1,226	1,118	1,226
Commercial lending | Real estate loan | Principal | Multifamily residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,118	1,226	1,118	1,226
Commercial lending | Real estate loan | Principal and Interest | Multifamily residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Real estate loan | Interest Deferments | Multifamily residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Real estate loan | Interest Rate Reduction | Multifamily residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Total CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,118	22,468	1,118	22,468
Commercial lending | Total CRE | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,118	22,468	1,118	22,468
Commercial lending | Total CRE | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Total CRE | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Total CRE | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		$ 0	$ 0	$ 0