Goodwill and Other Amortizing Intangible Assets - Summarized Other Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	$ 31,455	$ 20,126
Accumulated Amortization	(19,442)	(18,895)
Net Intangible Assets	12,013	1,231
Customer Deposit Intangibles [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	30,471	19,142
Accumulated Amortization	(18,998)	(18,619)
Net Intangible Assets	11,473	523
Customer list intangible
Finite-Lived Intangible Assets [Line Items]
Gross Intangible Assets	984	984
Accumulated Amortization	(444)	(276)
Net Intangible Assets	$ 540	$ 708