Loans Receivable and Allowance for Credit Losses (Non-PCI TDR Modifications) (Details) - Non-PCI Loans - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	$ 7,029	$ 8,006	$ 82,283	$ 10,666
Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	6,000	8,006	44,271	9,470
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	798
Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	893	0	1,109	0
Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	136	0	36,903	398
Commercial lending
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	6,000	8,006	81,038	8,804
Commercial lending | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	6,000	8,006	44,271	8,006
Commercial lending | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	798
Commercial lending | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	36,767	0
Commercial lending | Commercial and industrial (“C&I”)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	6,000	8,006	81,038	8,006
Commercial lending | Commercial and industrial (“C&I”) | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	6,000	8,006	44,271	8,006
Commercial lending | Commercial and industrial (“C&I”) | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Commercial and industrial (“C&I”) | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	0
Commercial lending | Commercial and industrial (“C&I”) | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	36,767	0
Commercial lending | Commercial real estate (“CRE”)
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	798
Commercial lending | Commercial real estate (“CRE”) | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0	0
Commercial lending | Commercial real estate (“CRE”) | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0	798
Commercial lending | Commercial real estate (“CRE”) | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0	0
Commercial lending | Commercial real estate (“CRE”) | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment			0	0
Consumer lending
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	1,029	0	1,245	1,862
Consumer lending | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	1,464
Consumer lending | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	0
Consumer lending | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	893	0	1,109	0
Consumer lending | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	136	0	136	398
Consumer lending | Real estate loan | Single-family residential
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	893	0	1,109	395
Consumer lending | Real estate loan | Single-family residential | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	64
Consumer lending | Real estate loan | Single-family residential | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	0
Consumer lending | Real estate loan | Single-family residential | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	893	0	1,109	0
Consumer lending | Real estate loan | Single-family residential | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	331
Consumer lending | HELOCs
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	136	0	136	1,467
Consumer lending | HELOCs | Principal
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	1,400
Consumer lending | HELOCs | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	0
Consumer lending | HELOCs | Interest Deferments
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	0	0	0	0
Consumer lending | HELOCs | Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Post- Modification Outstanding Recorded Investment	$ 136	$ 0	$ 136	$ 67