Loans Receivable and Allowance for Credit Losses (Additions to TDRs) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan
Loans Modified as TDRs
Number of Loans | loan	9		14
Pre- Modification Outstanding Recorded Investment	$ 66,027		$ 115,884
Post- Modification Outstanding Recorded Investment	58,036		102,181
Financial Impact	$ 12,129		$ 12,528
Commercial lending
Loans Modified as TDRs
Number of Loans | loan	9		14
Pre- Modification Outstanding Recorded Investment	$ 66,027		$ 115,884
Post- Modification Outstanding Recorded Investment	58,036		102,181
Financial Impact	$ 12,129		$ 12,528
Commercial lending | Commercial and industrial (“C&I”)
Loans Modified as TDRs
Number of Loans | loan	6		11
Pre- Modification Outstanding Recorded Investment	$ 43,378		$ 93,235
Post- Modification Outstanding Recorded Investment	35,568		79,713
Financial Impact	$ 12,108		$ 12,507
Commercial lending | Commercial real estate (“CRE”)
Loans Modified as TDRs
Number of Loans | loan	2		2
Pre- Modification Outstanding Recorded Investment	$ 21,429		$ 21,429
Post- Modification Outstanding Recorded Investment	21,242		21,242
Financial Impact	$ 21		$ 21
Commercial lending | Real estate loan | Multifamily residential
Loans Modified as TDRs
Number of Loans | loan	1		1
Pre- Modification Outstanding Recorded Investment	$ 1,220		$ 1,220
Post- Modification Outstanding Recorded Investment	1,226		1,226
Financial Impact	$ 0		$ 0
Commercial lending | Total CRE
Loans Modified as TDRs
Number of Loans | loan	3		3
Pre- Modification Outstanding Recorded Investment	$ 22,649		$ 22,649
Post- Modification Outstanding Recorded Investment	22,468		22,468
Financial Impact	$ 21		$ 21
Consumer lending
Loans Modified as TDRs
Number of Loans | loan	0		0
Pre- Modification Outstanding Recorded Investment	$ 0		$ 0
Post- Modification Outstanding Recorded Investment	0		0
Financial Impact	$ 0		$ 0
Consumer lending | Real estate loan | Single-family residential
Loans Modified as TDRs
Number of Loans | loan	0		0
Pre- Modification Outstanding Recorded Investment	$ 0		$ 0
Post- Modification Outstanding Recorded Investment	0		0
Financial Impact	$ 0		$ 0
Consumer lending | HELOCs
Loans Modified as TDRs
Number of Loans | loan	0		0
Pre- Modification Outstanding Recorded Investment	$ 0		$ 0
Post- Modification Outstanding Recorded Investment	0		0
Financial Impact	$ 0		$ 0
Consumer lending | Total residential mortgage
Loans Modified as TDRs
Number of Loans | loan	0		0
Pre- Modification Outstanding Recorded Investment	$ 0		$ 0
Post- Modification Outstanding Recorded Investment	0		0
Financial Impact	$ 0		$ 0
Non-PCI Loans
Loans Modified as TDRs
Number of Loans | loan		3		12
Pre- Modification Outstanding Recorded Investment		$ 8,975		$ 86,335
Post- Modification Outstanding Recorded Investment		7,029		82,283
Financial Impact		$ 2,396		$ 9,233
Non-PCI Loans | Commercial lending
Loans Modified as TDRs
Number of Loans | loan		1		9
Pre- Modification Outstanding Recorded Investment		$ 7,933		$ 85,073
Post- Modification Outstanding Recorded Investment		6,000		81,038
Financial Impact		$ 2,396		$ 9,231
Non-PCI Loans | Commercial lending | Commercial and industrial (“C&I”)
Loans Modified as TDRs
Number of Loans | loan		1		9
Pre- Modification Outstanding Recorded Investment		$ 7,933		$ 85,073
Post- Modification Outstanding Recorded Investment		6,000		81,038
Financial Impact		$ 2,396		$ 9,231
Non-PCI Loans | Commercial lending | Commercial real estate (“CRE”)
Loans Modified as TDRs
Number of Loans | loan		0		0
Pre- Modification Outstanding Recorded Investment		$ 0		$ 0
Post- Modification Outstanding Recorded Investment		0		0
Financial Impact		$ 0		$ 0
Non-PCI Loans | Commercial lending | Real estate loan | Multifamily residential
Loans Modified as TDRs
Number of Loans | loan		0		0
Pre- Modification Outstanding Recorded Investment		$ 0		$ 0
Post- Modification Outstanding Recorded Investment		0		0
Financial Impact		$ 0		$ 0
Non-PCI Loans | Commercial lending | Total CRE
Loans Modified as TDRs
Number of Loans | loan		0		0
Pre- Modification Outstanding Recorded Investment		$ 0		$ 0
Post- Modification Outstanding Recorded Investment		0		0
Financial Impact		$ 0		$ 0
Non-PCI Loans | Consumer lending
Loans Modified as TDRs
Number of Loans | loan		2		3
Pre- Modification Outstanding Recorded Investment		$ 1,042		$ 1,262
Post- Modification Outstanding Recorded Investment		1,029		1,245
Financial Impact		$ 0		$ 2
Non-PCI Loans | Consumer lending | Real estate loan | Single-family residential
Loans Modified as TDRs
Number of Loans | loan		1		2
Pre- Modification Outstanding Recorded Investment		$ 903		$ 1,123
Post- Modification Outstanding Recorded Investment		893		1,109
Financial Impact		$ 0		$ 2
Non-PCI Loans | Consumer lending | HELOCs
Loans Modified as TDRs
Number of Loans | loan		1		1
Pre- Modification Outstanding Recorded Investment		$ 139		$ 139
Post- Modification Outstanding Recorded Investment		136		136
Financial Impact		$ 0		$ 0
Non-PCI Loans | Consumer lending | Total residential mortgage
Loans Modified as TDRs
Number of Loans | loan		2		3
Pre- Modification Outstanding Recorded Investment		$ 1,042		$ 1,262
Post- Modification Outstanding Recorded Investment		1,029		1,245
Financial Impact		$ 0		$ 2