Goodwill and Other Intangible Assets (Gross Carrying Value And Accumulated Amortization Of Other Intangible Assets) (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 47,625	$ 43,000
Accumulated Amortization	24,096	21,083
Net Carrying Amount	$ 23,529	21,917
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	9 years
Core Deposits [Member] | HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 26,625	22,000
Accumulated Amortization	14,875	13,073
Net Carrying Amount	11,750	8,927
Customer Relationships [Member] | HSA Bank [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	21,000	21,000
Accumulated Amortization	9,221	8,010
Net Carrying Amount	$ 11,779	$ 12,990