Loans Receivable and Allowance for Credit Losses (TDR Post-Modifications) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	$ 156,914	$ 92,649	$ 12,081
Financing Receivable, Troubled Debt Restructuring, Commitment to Lend	3,000	2,200
Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	81,581
Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	10,863
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	31,913
Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	32,557
Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	156,914	91,023	10,272
Commercial Lending | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	81,581
Commercial Lending | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	10,863
Commercial Lending | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	31,913
Commercial Lending | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	32,557
Commercial Lending | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | C&I
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	134,467	71,332	9,520
Commercial Lending | C&I | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	59,134
Commercial Lending | C&I | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	10,863
Commercial Lending | C&I | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	31,913
Commercial Lending | C&I | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	32,557
Commercial Lending | C&I | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	21,221		752
Commercial Lending | CRE | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	21,221
Commercial Lending | CRE | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | CRE | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | CRE | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | CRE | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Residential loan | Multifamily
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,226
Commercial Lending | Residential loan | Multifamily | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,226
Commercial Lending | Residential loan | Multifamily | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Residential loan | Multifamily | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Residential loan | Multifamily | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Residential loan | Multifamily | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Construction and land
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		19,691
Commercial Lending | Total CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	22,447	19,691	752
Commercial Lending | Total CRE | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	22,447
Commercial Lending | Total CRE | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Total CRE | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Total CRE | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Total CRE | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Consumer Lending
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	1,626	1,809
Consumer Lending | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Consumer Lending | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Consumer Lending | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Consumer Lending | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Consumer Lending | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	$ 0
Consumer Lending | Residential loan | Single-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		1,098	391
Consumer Lending | HELOCs
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		528	1,418
Consumer Lending | Total residential mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		1,626	1,809
Non-PCI impaired loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		92,649	12,081
Non-PCI impaired loans | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		31,611	6,891
Non-PCI impaired loans | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		1,495	0
Non-PCI impaired loans | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		19,691	752
Non-PCI impaired loans | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		39,852	4,438
Non-PCI impaired loans | Commercial Lending
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		91,023	10,272
Non-PCI impaired loans | Commercial Lending | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		31,611	5,472
Non-PCI impaired loans | Commercial Lending | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Commercial Lending | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		19,691	752
Non-PCI impaired loans | Commercial Lending | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Commercial Lending | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		39,721	4,048
Non-PCI impaired loans | Commercial Lending | C&I
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		71,332	9,520
Non-PCI impaired loans | Commercial Lending | C&I | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		31,611	5,472
Non-PCI impaired loans | Commercial Lending | C&I | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Commercial Lending | C&I | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Commercial Lending | C&I | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Commercial Lending | C&I | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		39,721	4,048
Non-PCI impaired loans | Commercial Lending | CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment			752
Non-PCI impaired loans | Commercial Lending | CRE | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment			0
Non-PCI impaired loans | Commercial Lending | CRE | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment			0
Non-PCI impaired loans | Commercial Lending | CRE | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment			752
Non-PCI impaired loans | Commercial Lending | CRE | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment			0
Non-PCI impaired loans | Commercial Lending | CRE | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment			0
Non-PCI impaired loans | Commercial Lending | Construction and land
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		19,691
Non-PCI impaired loans | Commercial Lending | Construction and land | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0
Non-PCI impaired loans | Commercial Lending | Construction and land | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0
Non-PCI impaired loans | Commercial Lending | Construction and land | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		19,691
Non-PCI impaired loans | Commercial Lending | Construction and land | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0
Non-PCI impaired loans | Commercial Lending | Construction and land | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0
Non-PCI impaired loans | Commercial Lending | Total CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		19,691	752
Non-PCI impaired loans | Commercial Lending | Total CRE | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Commercial Lending | Total CRE | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Commercial Lending | Total CRE | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		19,691	752
Non-PCI impaired loans | Commercial Lending | Total CRE | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Commercial Lending | Total CRE | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Consumer Lending
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		1,626	1,809
Non-PCI impaired loans | Consumer Lending | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	1,419
Non-PCI impaired loans | Consumer Lending | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		1,495	0
Non-PCI impaired loans | Consumer Lending | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Consumer Lending | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Consumer Lending | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		131	390
Non-PCI impaired loans | Consumer Lending | Residential loan | Single-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		1,098	391
Non-PCI impaired loans | Consumer Lending | Residential loan | Single-family | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	66
Non-PCI impaired loans | Consumer Lending | Residential loan | Single-family | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		1,098	0
Non-PCI impaired loans | Consumer Lending | Residential loan | Single-family | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Consumer Lending | Residential loan | Single-family | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Consumer Lending | Residential loan | Single-family | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	325
Non-PCI impaired loans | Consumer Lending | HELOCs
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		528	1,418
Non-PCI impaired loans | Consumer Lending | HELOCs | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	1,353
Non-PCI impaired loans | Consumer Lending | HELOCs | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		397	0
Non-PCI impaired loans | Consumer Lending | HELOCs | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Consumer Lending | HELOCs | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Consumer Lending | HELOCs | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		131	65
Non-PCI impaired loans | Consumer Lending | Total residential mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		1,626	1,809
Non-PCI impaired loans | Consumer Lending | Total residential mortgage | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	1,419
Non-PCI impaired loans | Consumer Lending | Total residential mortgage | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		1,495	0
Non-PCI impaired loans | Consumer Lending | Total residential mortgage | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Consumer Lending | Total residential mortgage | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Non-PCI impaired loans | Consumer Lending | Total residential mortgage | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		$ 131	$ 390