Loans Receivable and Allowance for Credit Losses (Non-PCI Impaired Loans) (Details) - Non-PCI impaired loans - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Impaired loans disclosures
Unpaid Principal Balance	$ 171,016	$ 255,273
Recorded Investment With No Allowance	79,064	121,934
Recorded Investment With Allowance	91,823	84,121
Total Recorded Investment	170,887	206,055
Individually evaluated for impairment	19,895	12,701
Related Allowance	19,895	12,701
Average Recorded Investment	185,132	236,227	$ 172,269
Recognized Interest Income	2,989	4,711	1,714
Commercial Lending
Impaired loans disclosures
Unpaid Principal Balance	149,037	235,822
Recorded Investment With No Allowance	76,777	121,934
Recorded Investment With Allowance	72,073	66,104
Total Recorded Investment	148,850	188,038
Related Allowance	16,866	11,983
Average Recorded Investment	162,502	218,201	155,652
Recognized Interest Income	2,517	4,201	1,425
Commercial Lending \| C&I
Impaired loans disclosures
Unpaid Principal Balance	98,889	167,466
Recorded Investment With No Allowance	36,086	78,316
Recorded Investment With Allowance	62,599	47,303
Total Recorded Investment	98,685	125,619
Individually evaluated for impairment	16,094	10,477
Average Recorded Investment	110,662	148,986	85,290
Recognized Interest Income	1,517	2,612	538
Commercial Lending \| CRE
Impaired loans disclosures
Unpaid Principal Balance	35,550	50,718
Recorded Investment With No Allowance	28,699	32,507
Recorded Investment With Allowance	6,857	14,001
Total Recorded Investment	35,556	46,508
Individually evaluated for impairment	684	1,263
Average Recorded Investment	36,003	47,064	43,598
Recognized Interest Income	578	1,253	536
Commercial Lending \| Residential loan \| Multifamily
Impaired loans disclosures
Unpaid Principal Balance	10,625	11,181
Recorded Investment With No Allowance	8,019	5,684
Recorded Investment With Allowance	2,617	4,357
Total Recorded Investment	10,636	10,041
Individually evaluated for impairment	88	180
Average Recorded Investment	11,455	15,763	24,024
Recognized Interest Income	422	302	312
Commercial Lending \| Construction and land
Impaired loans disclosures
Unpaid Principal Balance	3,973	6,457
Recorded Investment With No Allowance	3,973	5,427
Recorded Investment With Allowance	0	443
Total Recorded Investment	3,973	5,870
Individually evaluated for impairment	0	63
Average Recorded Investment	4,382	6,388	2,740
Recognized Interest Income	0	34	39
Consumer Lending
Impaired loans disclosures
Unpaid Principal Balance	21,979	19,451
Recorded Investment With No Allowance	2,287	0
Recorded Investment With Allowance	19,750	18,017
Total Recorded Investment	22,037	18,017
Related Allowance	3,029	718
Average Recorded Investment	22,630	18,026	16,617
Recognized Interest Income	472	510	289
Consumer Lending \| Residential loan \| Single-family
Impaired loans disclosures
Unpaid Principal Balance	14,287	15,435
Recorded Investment With No Allowance	0	0
Recorded Investment With Allowance	14,338	14,335
Total Recorded Investment	14,338	14,335
Individually evaluated for impairment	534	687
Average Recorded Investment	14,994	14,323	15,365
Recognized Interest Income	417	447	242
Consumer Lending \| HELOCs
Impaired loans disclosures
Unpaid Principal Balance	5,201	4,016
Recorded Investment With No Allowance	2,287	0
Recorded Investment With Allowance	2,921	3,682
Total Recorded Investment	5,208	3,682
Individually evaluated for impairment	4	31
Average Recorded Investment	5,494	3,703	1,252
Recognized Interest Income	55	63	47
Consumer Lending \| Other consumer
Impaired loans disclosures
Unpaid Principal Balance	2,491
Recorded Investment With No Allowance	0
Recorded Investment With Allowance	2,491
Total Recorded Investment	2,491
Individually evaluated for impairment	2,491	0
Average Recorded Investment	2,142	0	0
Recognized Interest Income	$ 0	$ 0	$ 0

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5258-111524

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953550-111524

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