Goodwill and Other Amortizing Intangible Assets - Summarized Other Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 21,754	$ 31,455
Accumulated Amortization	(6,822)	(19,442)
Net Intangible Assets	14,932	12,013
Customer Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	19,471	30,471
Accumulated Amortization	(6,071)	(18,998)
Net Intangible Assets	13,400	11,473
Customer list intangible
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	2,283	984
Accumulated Amortization	(751)	(444)
Net Intangible Assets	$ 1,532	$ 540

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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