Loans Receivable and Allowance for Credit Losses (Non-PCI TDR Modifications) (Details) - Non-PCI impaired loans - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	$ 92,649	$ 12,081	$ 43,651
Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	31,611	6,891	19,164
Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,495	0	8,003
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	19,691	752	0
Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	39,852	4,438	16,484
Commercial Lending
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	91,023	10,272	43,496
Commercial Lending | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	31,611	5,472	19,164
Commercial Lending | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	7,848
Commercial Lending | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	19,691	752	0
Commercial Lending | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	39,721	4,048	16,484
Commercial Lending | C&I
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	71,332	9,520	37,900
Commercial Lending | C&I | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	31,611	5,472	13,568
Commercial Lending | C&I | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	7,848
Commercial Lending | C&I | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0
Commercial Lending | C&I | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	39,721	4,048	16,484
Commercial Lending | CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		752	2,627
Commercial Lending | CRE | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	2,627
Commercial Lending | CRE | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Commercial Lending | CRE | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		752	0
Commercial Lending | CRE | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment		0	0
Commercial Lending | Residential loan | Multifamily
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment			2,969
Commercial Lending | Residential loan | Multifamily | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment			2,969
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 | 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 | Construction and land | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Construction and land | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Construction and land | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	19,691
Commercial Lending | Construction and land | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0
Commercial Lending | Total CRE
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	19,691	752	5,596
Commercial Lending | Total CRE | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	5,596
Commercial Lending | Total CRE | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0
Commercial Lending | Total CRE | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	19,691	752	0
Commercial Lending | Total CRE | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0
Consumer Lending
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,626	1,809	155
Consumer Lending | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	1,419	0
Consumer Lending | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,495	0	155
Consumer Lending | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0
Consumer Lending | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	131	390	0
Consumer Lending | Residential loan | Single-family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,098	391
Consumer Lending | Residential loan | Single-family | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	66
Consumer Lending | Residential loan | Single-family | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,098	0
Consumer Lending | Residential loan | Single-family | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0
Consumer Lending | Residential loan | Single-family | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	325
Consumer Lending | HELOCs
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	528	1,418	155
Consumer Lending | HELOCs | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	1,353	0
Consumer Lending | HELOCs | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	397	0	155
Consumer Lending | HELOCs | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0
Consumer Lending | HELOCs | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	131	65	0
Consumer Lending | Total residential mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,626	1,809	155
Consumer Lending | Total residential mortgage | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	1,419	0
Consumer Lending | Total residential mortgage | Principal and Interest
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	1,495	0	155
Consumer Lending | Total residential mortgage | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	0	0	0
Consumer Lending | Total residential mortgage | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post-Modification Outstanding Recorded Investment	$ 131	$ 390	$ 0