Goodwill and Other Intangible Assets (Goodwill Reporting Unit) (Details) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($) segment
Goodwill [Line Items]
Number of reportable segments \| segment	3
Goodwill [Roll Forward]
Goodwill, beginning	$ 469,433
Goodwill, end	465,547
Consumer and Business Banking
Goodwill [Roll Forward]
Goodwill, beginning	357,207
Goodwill, end	353,321
Commercial Banking
Goodwill [Roll Forward]
Goodwill, beginning	112,226
Goodwill, end	112,226
Desert Community Bank
Goodwill [Roll Forward]
Disposition	(3,886)
Desert Community Bank \| Consumer and Business Banking
Goodwill [Roll Forward]
Disposition	(3,886)
Desert Community Bank \| Commercial Banking
Goodwill [Roll Forward]
Disposition	$ 0

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

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Period Type:	duration

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
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- Details

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