Loans Receivable and Allowance for Credit Losses (Details 4) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Nonaccrual and Past Due Loans
Number of days beyond loan classified nonaccrual	90 days
Total loans	$ 28,525,357	$ 25,503,139
CRE
Nonaccrual and Past Due Loans
Total loans	9,527,180	8,690,863
CRE | Income producing
Nonaccrual and Past Due Loans
Total loans	8,843,776	8,016,109
CRE | Construction
Nonaccrual and Past Due Loans
Total loans	572,027	551,560
CRE | Land
Nonaccrual and Past Due Loans
Total loans	111,377	123,194
C&I
Nonaccrual and Past Due Loans
Total loans	10,645,156	9,640,563
C&I | Commercial business
Nonaccrual and Past Due Loans
Total loans	9,776,254	8,959,633
C&I | Trade finance
Nonaccrual and Past Due Loans
Total loans	868,902	680,930
Residential
Nonaccrual and Past Due Loans
Total loans	6,232,965	5,095,718
Residential | Real estate loan | Single-family
Nonaccrual and Past Due Loans
Total loans	4,356,009	3,509,779
Residential | Real estate loan | Multifamily
Nonaccrual and Past Due Loans
Total loans	1,876,956	1,585,939
Consumer
Nonaccrual and Past Due Loans
Total loans	2,120,056	2,075,995
Non-PCI Loans
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	73,206	101,189
Total Nonaccrual Loans	114,725	122,817
Current Accruing Loans	27,805,153	24,636,688
Total loans	27,993,084	24,860,694
Non-PCI Loans | CRE
Nonaccrual and Past Due Loans
Total loans	9,213,552	8,340,497
Non-PCI Loans | CRE | Income producing
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	7,135	20,313
Total Nonaccrual Loans	24,802	26,907
Current Accruing Loans	8,498,582	7,620,441
Total loans	8,530,519	7,667,661
Non-PCI Loans | CRE | Construction
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	9,000	4,994
Total Nonaccrual Loans	0	0
Current Accruing Loans	563,027	546,566
Total loans	572,027	551,560
Non-PCI Loans | CRE | Land
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	0	0
Total Nonaccrual Loans	4,183	5,326
Current Accruing Loans	106,823	115,950
Total loans	111,006	121,276
Non-PCI Loans | C&I
Nonaccrual and Past Due Loans
Total loans	10,632,590	9,602,176
Non-PCI Loans | C&I | Commercial business
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	16,423	47,331
Total Nonaccrual Loans	73,384	81,248
Current Accruing Loans	9,673,881	8,792,667
Total loans	9,763,688	8,921,246
Non-PCI Loans | C&I | Trade finance
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	0	0
Total Nonaccrual Loans	0	8
Current Accruing Loans	868,902	680,922
Total loans	868,902	680,930
Non-PCI Loans | Residential
Nonaccrual and Past Due Loans
Total loans	6,042,328	4,860,954
Non-PCI Loans | Residential | Real estate loan | Single-family
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	18,325	17,671
Total Nonaccrual Loans	6,639	4,214
Current Accruing Loans	4,209,053	3,348,784
Total loans	4,234,017	3,370,669
Non-PCI Loans | Residential | Real estate loan | Multifamily
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	8,140	4,325
Total Nonaccrual Loans	2,620	2,984
Current Accruing Loans	1,797,551	1,482,976
Total loans	1,808,311	1,490,285
Non-PCI Loans | Consumer
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	14,183	6,555
Total Nonaccrual Loans	3,097	2,130
Current Accruing Loans	2,087,334	2,048,382
Total loans	2,104,614	2,057,067
Non-PCI Loans | Accruing Loans 30-59 Days Past Due
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	63,604	73,152
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | CRE | Income producing
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	5,211	6,233
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | CRE | Construction
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	9,000	4,994
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | CRE | Land
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	0	0
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | C&I | Commercial business
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	16,315	45,052
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | C&I | Trade finance
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	0	0
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | Residential | Real estate loan | Single-family
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	16,765	9,595
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | Residential | Real estate loan | Multifamily
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	7,476	3,951
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	8,837	3,327
Non-PCI Loans | Accruing Loans 60-89 Days Past Due
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	9,602	28,037
Non-PCI Loans | Accruing Loans 60-89 Days Past Due | CRE | Income producing
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	1,924	14,080
Non-PCI Loans | Accruing Loans 60-89 Days Past Due | CRE | Construction
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	0	0
Non-PCI Loans | Accruing Loans 60-89 Days Past Due | CRE | Land
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	0	0
Non-PCI Loans | Accruing Loans 60-89 Days Past Due | C&I | Commercial business
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	108	2,279
Non-PCI Loans | Accruing Loans 60-89 Days Past Due | C&I | Trade finance
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	0	0
Non-PCI Loans | Accruing Loans 60-89 Days Past Due | Residential | Real estate loan | Single-family
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	1,560	8,076
Non-PCI Loans | Accruing Loans 60-89 Days Past Due | Residential | Real estate loan | Multifamily
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	664	374
Non-PCI Loans | Accruing Loans 60-89 Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	5,346	3,228
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	41,256	78,779
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | CRE | Income producing
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	4,853	14,872
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | CRE | Construction
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	0	0
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | CRE | Land
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	10	433
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | C&I | Commercial business
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	34,844	60,511
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | C&I | Trade finance
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	0	8
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | Residential | Real estate loan | Single-family
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	0	0
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | Residential | Real estate loan | Multifamily
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	1,456	2,790
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	93	165
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	73,469	44,038
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | CRE | Income producing
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	19,949	12,035
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | CRE | Construction
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	0	0
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | CRE | Land
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	4,173	4,893
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | C&I | Commercial business
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	38,540	20,737
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | C&I | Trade finance
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	0	0
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | Residential | Real estate loan | Single-family
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	6,639	4,214
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | Residential | Real estate loan | Multifamily
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	1,164	194
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	$ 3,004	$ 1,965