Loans Receivable and Allowance for Credit Losses (Details 10) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Allowance for loan losses
Beginning balance			$ 260,520
Charge-offs	$ (117)	$ (37)	(209)	$ (1,900)
Ending balance	276,316		276,316
CRE
Allowance for loan losses
Beginning balance			72,916
Ending balance	74,063		74,063
C&I
Allowance for loan losses
Beginning balance			142,167
Ending balance	150,136		150,136
Residential
Allowance for loan losses
Beginning balance			37,338
Ending balance	43,679		43,679
Consumer
Allowance for loan losses
Beginning balance			8,099
Ending balance	8,438		8,438
PCI Loans
Allowance for loan losses
Beginning balance			118
Ending balance	78		78
PCI Loans | CRE
Allowance for loan losses
Beginning balance			112
Ending balance	78		78
PCI Loans | C&I
Allowance for loan losses
Beginning balance			1
Ending balance	0		0
PCI Loans | Residential
Allowance for loan losses
Beginning balance			5
Ending balance	0		0
PCI Loans | Consumer
Allowance for loan losses
Beginning balance			0
Ending balance	0		0
Loans Receivable
Allowance for loan losses
Beginning balance	263,094	260,238	260,520	264,959
(Reversal of) provision for loan losses	10,671	7,149	18,686	7,535
Charge-offs	(5,391)	(2,356)	(12,600)	(8,410)
Recoveries	7,942	1,737	9,710	2,684
Net recoveries (charge-offs)	2,551	(619)	(2,890)	(5,726)
Ending balance	276,316	266,768	276,316	266,768
Loans Receivable | PCI Loans
Allowance for loan losses
Beginning balance	87	328	118	359
(Reversal of) provision for loan losses	(9)	(71)	(40)	(102)
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Net recoveries (charge-offs)	0	0	0	0
Ending balance	78	257	78	257
Loans Receivable | Non-PCI Loans
Allowance for loan losses
Beginning balance	263,007	259,910	260,402	264,600
(Reversal of) provision for loan losses	10,680	7,220	18,726	7,637
Charge-offs	(5,391)	(2,356)	(12,600)	(8,410)
Recoveries	7,942	1,737	9,710	2,684
Net recoveries (charge-offs)	2,551	(619)	(2,890)	(5,726)
Ending balance	276,238	266,511	276,238	266,511
Loans Receivable | Non-PCI Loans | CRE
Allowance for loan losses
Beginning balance	74,888	82,538	72,804	81,191
(Reversal of) provision for loan losses	(1,413)	(4,439)	226	(3,133)
Charge-offs	(1)	(139)	(149)	(195)
Recoveries	511	142	1,104	239
Net recoveries (charge-offs)	510	3	955	44
Ending balance	73,985	78,102	73,985	78,102
Loans Receivable | Non-PCI Loans | C&I
Allowance for loan losses
Beginning balance	137,510	134,077	142,166	134,597
(Reversal of) provision for loan losses	10,974	15,347	12,920	20,001
Charge-offs	(5,386)	(2,214)	(12,443)	(8,074)
Recoveries	7,038	1,217	7,493	1,903
Net recoveries (charge-offs)	1,652	(997)	(4,950)	(6,171)
Ending balance	150,136	148,427	150,136	148,427
Loans Receivable | Non-PCI Loans | Residential
Allowance for loan losses
Beginning balance	41,746	33,935	37,333	39,292
(Reversal of) provision for loan losses	1,563	(2,671)	5,398	(7,988)
Charge-offs	(1)	0	(1)	(137)
Recoveries	371	297	949	394
Net recoveries (charge-offs)	370	297	948	257
Ending balance	43,679	31,561	43,679	31,561
Loans Receivable | Non-PCI Loans | Consumer
Allowance for loan losses
Beginning balance	8,863	9,360	8,099	9,520
(Reversal of) provision for loan losses	(444)	(1,017)	182	(1,243)
Charge-offs	(3)	(3)	(7)	(4)
Recoveries	22	81	164	148
Net recoveries (charge-offs)	19	78	157	144
Ending balance	$ 8,438	$ 8,421	$ 8,438	$ 8,421