Securities - Available for Sale Securities (Unrealized Loss Position) (Parenthetical) (Detail) - Maximum [Member] - Other Securities [Member] - USD ($)	6 Months Ended	12 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Gross unrealized losses, held-to-maturity securities	$ 1,000,000	$ 1,000,000	$ 1,000,000
Gross unrealized losses, available for sale securities		$ 1,000,000

Amount of unrealized loss on securities classified as available-for-sale.

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- Definition

Amount of unrealized loss on investments in held-to-maturity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

+ Details

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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