Acquisitions - Summary of Loans Acquired (Detail) (Somerset Hills Bancorp [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2013
Business Acquisition [Line Items]
Contractually required principal and interest at acquisition	$ 356,655
Contractual cash flows not expected to be collected (non-accretable difference)	2,541
Expected cash flows at acquisition	354,114
Interest component of expected cash flows (accretable difference)	107,694
Fair value of acquired loans, including mortgages held for sale	246,420
Acquired Credit Impaired Loans [Member]
Business Acquisition [Line Items]
Contractually required principal and interest at acquisition	4,507
Contractual cash flows not expected to be collected (non-accretable difference)	2,541
Expected cash flows at acquisition	1,966
Interest component of expected cash flows (accretable difference)	361
Fair value of acquired loans, including mortgages held for sale	1,605
Acquired Non-Credit Impaired Loans [Member]
Business Acquisition [Line Items]
Contractually required principal and interest at acquisition	352,148
Expected cash flows at acquisition	352,148
Interest component of expected cash flows (accretable difference)	107,333
Fair value of acquired loans, including mortgages held for sale	$ 244,815

Fair Value Of Acquired Loans Including Mortgages Held For Sale

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- Definition

Interest Component Of Expected Cash Flows Accretable Difference

+ References

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- Definition

Amount of cash flows expected to be collected at acquisition of acquired loans accounted for as debt securities with evidence of deterioration of credit quality.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 15

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=27045933&loc=d3e13503-111538

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544

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- Definition

Amount of contractually required payments receivable at acquisition of acquired loans accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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- Definition

The amount of the loan's contractually required payments receivable in excess of the amount of its cash flows expected to be collected. This relates to loans with deteriorating of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

No definition available.

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