Loans Receivable and Allowance for Credit Losses (Details 10) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Allowance for loan losses
Beginning balance	$ 276,316	$ 266,768	$ 260,520	$ 264,959
(Reversal of) provision for loan losses	13,448	11,514	32,134	19,049
Charge-offs	(7,424)	(24,047)	(20,024)	(32,457)
Recoveries	3,586	1,577	13,296	4,261
Net recoveries (charge-offs)	(3,838)	(22,470)	(6,728)	(28,196)
Ending balance	285,926	255,812	285,926	255,812
CRE
Allowance for loan losses
Beginning balance			72,916
Ending balance	74,317		74,317
C&I
Allowance for loan losses
Beginning balance			142,167
Charge-offs	(232)		(441)
Ending balance	160,598		160,598
Residential
Allowance for loan losses
Beginning balance			37,338
Ending balance	43,905		43,905
Consumer
Allowance for loan losses
Beginning balance			8,099
Ending balance	7,106		7,106
Non-PCI Loans
Allowance for loan losses
Beginning balance	276,238	266,511	260,402	264,600
(Reversal of) provision for loan losses	13,458	11,615	32,184	19,252
Charge-offs	(7,424)	(24,047)	(20,024)	(32,457)
Recoveries	3,586	1,577	13,296	4,261
Net recoveries (charge-offs)	(3,838)	(22,470)	(6,728)	(28,196)
Ending balance	285,858	255,656	285,858	255,656
Non-PCI Loans | CRE
Allowance for loan losses
Beginning balance	73,985	78,102	72,804	81,191
(Reversal of) provision for loan losses	(346)	(6,598)	(120)	(9,731)
Charge-offs	0	(309)	(149)	(504)
Recoveries	610	634	1,714	873
Net recoveries (charge-offs)	610	325	1,565	369
Ending balance	74,249	71,829	74,249	71,829
Non-PCI Loans | C&I
Allowance for loan losses
Beginning balance	150,136	148,427	142,166	134,597
(Reversal of) provision for loan losses	15,656	18,548	28,576	38,549
Charge-offs	(7,359)	(23,696)	(19,802)	(31,770)
Recoveries	2,165	165	9,658	2,068
Net recoveries (charge-offs)	(5,194)	(23,531)	(10,144)	(29,702)
Ending balance	160,598	143,444	160,598	143,444
Non-PCI Loans | Residential
Allowance for loan losses
Beginning balance	43,679	31,561	37,333	39,292
(Reversal of) provision for loan losses	(583)	309	4,815	(7,679)
Charge-offs	0	(29)	(1)	(166)
Recoveries	809	654	1,758	1,048
Net recoveries (charge-offs)	809	625	1,757	882
Ending balance	43,905	32,495	43,905	32,495
Non-PCI Loans | Consumer
Allowance for loan losses
Beginning balance	8,438	8,421	8,099	9,520
(Reversal of) provision for loan losses	(1,269)	(644)	(1,087)	(1,887)
Charge-offs	(65)	(13)	(72)	(17)
Recoveries	2	124	166	272
Net recoveries (charge-offs)	(63)	111	94	255
Ending balance	7,106	7,888	7,106	7,888
PCI Loans
Allowance for loan losses
Beginning balance	78	257	118	359
(Reversal of) provision for loan losses	(10)	(101)	(50)	(203)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Net recoveries (charge-offs)	0	0	0	0
Ending balance	$ 68	$ 156	$ 68	$ 156