Investment Securities (Disclosure Regarding Length of Time on Securities Available for Sale with Temporary Impairment) (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	$ 47,557	$ 138,283
Less than 12 months, gross unrealized losses	(547)	(644)
12 months or longer, fair value	14	46,819
12 months or longer, gross unrealized losses	(4)	(504)
Total, fair value	47,571	185,102
Total, gross unrealized losses	(551)	(1,148)
Mortgage-Backed Securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	45,567	136,270
Less than 12 months, gross unrealized losses	(510)	(629)
12 months or longer, fair value	14	46,819
12 months or longer, gross unrealized losses	(4)	(504)
Total, fair value	45,581	183,089
Total, gross unrealized losses	(514)	(1,133)
Corporate Obligations
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, fair value	1,990	2,013
Less than 12 months, gross unrealized losses	(37)	(15)
12 months or longer, fair value	0	0
12 months or longer, gross unrealized losses	0	0
Total, fair value	1,990	2,013
Total, gross unrealized losses	$ (37)	$ (15)

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118955579&loc=SL82922890-210455

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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