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.

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

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Number of reporting units tested for impairment of goodwill. A reporting unit is an operating segment or one level below an operating segment.

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Goodwill and Other Intangible Assets (Goodwill and Impairment) (Details)	1 Months Ended	9 Months Ended
	Mar. 31, 2018 USD ($)	Sep. 30, 2018 USD ($) segment	Dec. 31, 2017 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill		$ 465,547,000	$ 469,433,000
Number of reporting units \| segment		3
Goodwill impairment			$ 0
Desert Community Bank
Goodwill [Line Items]
Decrease in goodwill	$ (3,900,000)