Loans Receivable and Allowance for Credit Losses (Details 4) - Loans Receivable - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Nonaccrual and Past Due Loans
Number of days beyond loan classified nonaccrual	90 days
Total loans	$ 26,461,292	$ 25,503,139
CRE
Nonaccrual and Past Due Loans
Total loans	8,986,890	8,690,863
CRE | Income producing
Nonaccrual and Past Due Loans
Total loans	8,302,098	8,016,109
CRE | Construction
Nonaccrual and Past Due Loans
Total loans	562,560	551,560
CRE | Land
Nonaccrual and Past Due Loans
Total loans	122,232	123,194
C&I
Nonaccrual and Past Due Loans
Total loans	9,918,072	9,640,563
C&I | Commercial business
Nonaccrual and Past Due Loans
Total loans	9,208,857	8,959,633
C&I | Trade finance
Nonaccrual and Past Due Loans
Total loans	709,215	680,930
Residential
Nonaccrual and Past Due Loans
Total loans	5,432,767	5,095,718
Residential | Real estate loan | Single-family
Nonaccrual and Past Due Loans
Total loans	3,700,072	3,509,779
Residential | Real estate loan | Multifamily
Nonaccrual and Past Due Loans
Total loans	1,732,695	1,585,939
Consumer
Nonaccrual and Past Due Loans
Total loans	2,123,563	2,075,995
Non-PCI Loans
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	28,573	101,189
Total Nonaccrual Loans	141,155	122,817
Current Accruing Loans	25,679,900	24,636,688
Total loans	25,849,628	24,860,694
Non-PCI Loans | CRE
Nonaccrual and Past Due Loans
Total loans	8,647,669	8,340,497
Non-PCI Loans | CRE | Income producing
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	3,132	20,313
Total Nonaccrual Loans	33,716	26,907
Current Accruing Loans	7,927,376	7,620,441
Total loans	7,964,224	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	562,560	546,566
Total loans	562,560	551,560
Non-PCI Loans | CRE | Land
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	0	0
Total Nonaccrual Loans	4,500	5,326
Current Accruing Loans	116,385	115,950
Total loans	120,885	121,276
Non-PCI Loans | C&I
Nonaccrual and Past Due Loans
Total loans	9,885,962	9,602,176
Non-PCI Loans | C&I | Commercial business
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	8,483	47,331
Total Nonaccrual Loans	92,093	81,248
Current Accruing Loans	9,076,171	8,792,667
Total loans	9,176,747	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	709,215	680,922
Total loans	709,215	680,930
Non-PCI Loans | Residential
Nonaccrual and Past Due Loans
Total loans	5,209,906	4,860,954
Non-PCI Loans | Residential | Real estate loan | Single-family
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	7,457	17,671
Total Nonaccrual Loans	5,643	4,214
Current Accruing Loans	3,553,639	3,348,784
Total loans	3,566,739	3,370,669
Non-PCI Loans | Residential | Real estate loan | Multifamily
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	5,705	4,325
Total Nonaccrual Loans	2,222	2,984
Current Accruing Loans	1,635,240	1,482,976
Total loans	1,643,167	1,490,285
Non-PCI Loans | Consumer
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	3,796	6,555
Total Nonaccrual Loans	2,981	2,130
Current Accruing Loans	2,099,314	2,048,382
Total loans	2,106,091	2,057,067
Non-PCI Loans | Accruing Loans 30-59 Days Past Due
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	21,974	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	3,132	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	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	8,478	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	2,211	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	4,801	3,951
Non-PCI Loans | Accruing Loans 30-59 Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	3,352	3,327
Non-PCI Loans | Accruing Loans 60-89 Days Past Due
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	6,599	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	0	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	5	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	5,246	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	904	374
Non-PCI Loans | Accruing Loans 60-89 Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Accruing Past Due Loans	444	3,228
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	60,067	78,779
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | CRE | Income producing
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	11,596	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	47	433
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | C&I | Commercial business
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	47,238	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	1,030	2,790
Non-PCI Loans | Nonaccrual Loans Less Than 90 Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	156	165
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	81,088	44,038
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | CRE | Income producing
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	22,120	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	4,453	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	44,855	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	5,643	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	1,192	194
Non-PCI Loans | Nonaccrual Loans 90 or More Days Past Due | Consumer
Nonaccrual and Past Due Loans
Total Nonaccrual Loans	$ 2,825	$ 1,965