Loans Receivable and Allowance for Credit Losses (Details 4) - Loans Receivable - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Nonaccrual and Past Due Loans
Number of days beyond loan classified nonaccrual	90 days
Total loans	$ 27,210,666	$ 25,503,139
CRE
Nonaccrual and Past Due Loans
Total loans	9,125,849	8,690,863
CRE | Income producing
Nonaccrual and Past Due Loans
Total loans	8,465,030	8,016,109
CRE | Construction
Nonaccrual and Past Due Loans
Total loans	550,781	551,560
CRE | Land
Nonaccrual and Past Due Loans
Total loans	110,038	123,194
C&I
Nonaccrual and Past Due Loans
Total loans	10,187,349	9,640,563
C&I | Commercial business
Nonaccrual and Past Due Loans
Total loans	9,424,236	8,959,633
C&I | Trade finance
Nonaccrual and Past Due Loans
Total loans	763,113	680,930
Residential
Nonaccrual and Past Due Loans
Total loans	5,774,229	5,095,718
Residential | Real estate loan | Single-family
Nonaccrual and Past Due Loans
Total loans	4,001,488	3,509,779
Residential | Real estate loan | Multifamily
Nonaccrual and Past Due Loans
Total loans	1,772,741	1,585,939
Consumer
Nonaccrual and Past Due Loans
Total loans	2,123,239	2,075,995
Non-PCI Loans
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	36,689	101,189
Total Nonaccrual Loans	130,806	122,817
Current Accruing Loans	26,477,716	24,636,688
Total loans	26,645,211	24,860,694
Non-PCI Loans | CRE
Nonaccrual and Past Due Loans
Total loans	8,801,059	8,340,497
Non-PCI Loans | CRE | Income producing
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	5,477	20,313
Total Nonaccrual Loans	25,975	26,907
Current Accruing Loans	8,110,031	7,620,441
Total loans	8,141,483	7,667,661
Non-PCI Loans | CRE | Construction
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	0	4,994
Total Nonaccrual Loans	0	0
Current Accruing Loans	550,781	546,566
Total loans	550,781	551,560
Non-PCI Loans | CRE | Land
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	1,103	0
Total Nonaccrual Loans	4,344	5,326
Current Accruing Loans	103,348	115,950
Total loans	108,795	121,276
Non-PCI Loans | C&I
Nonaccrual and Past Due Loans
Total loans	10,166,688	9,602,176
Non-PCI Loans | C&I | Commercial business
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	12,102	47,331
Total Nonaccrual Loans	87,189	81,248
Current Accruing Loans	9,304,284	8,792,667
Total loans	9,403,575	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	763,113	680,922
Total loans	763,113	680,930
Non-PCI Loans | Residential
Nonaccrual and Past Due Loans
Total loans	5,570,781	4,860,954
Non-PCI Loans | Residential | Real estate loan | Single-family
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	7,948	17,671
Total Nonaccrual Loans	7,624	4,214
Current Accruing Loans	3,858,231	3,348,784
Total loans	3,873,803	3,370,669
Non-PCI Loans | Residential | Real estate loan | Multifamily
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	3,979	4,325
Total Nonaccrual Loans	2,678	2,984
Current Accruing Loans	1,690,321	1,482,976
Total loans	1,696,978	1,490,285
Non-PCI Loans | Consumer
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	6,080	6,555
Total Nonaccrual Loans	2,996	2,130
Current Accruing Loans	2,097,607	2,048,382
Total loans	2,106,683	2,057,067
Non-PCI Loans | Accruing Loans 30-59 Days Past Due
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	20,210	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	4,192	6,233
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | CRE | Construction
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	0	4,994
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | CRE | Land
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	1,103	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	2,976	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	4,581	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	3,611	3,951
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	3,747	3,327
Non-PCI Loans | Accruing Loans 60-89 Days Past Due
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	16,479	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	1,285	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	9,126	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	3,367	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	368	374
Non-PCI Loans | Accruing Loans 60-89 Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	2,333	3,228
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	56,425	78,779
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | CRE | Income producing
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	5,438	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	21	433
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | C&I | Commercial business
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	49,899	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	966	2,790
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	101	165
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	74,381	44,038
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | CRE | Income producing
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	20,537	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	4,323	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	37,290	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	7,624	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	1,712	194
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	$ 2,895	$ 1,965