Loan Servicing Rights - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017
Transfers and Servicing [Abstract]
Loan servicing rights	$ 24,303	$ 24,661	$ 25,023
Principal balance of loans serviced for others	3,306,000	3,321,000
Funds held in escrow	$ 37,800	8,900
Percentage of mortgage loan	99.70%
Fair value of servicing rights	$ 27,000	$ 25,800
Fair value at discount rate	13.00%	13.00%
Fair value inputs weighted average prepayment speed	115.00%	140.00%

Fair value inputs discount rate 1.

No definition available.

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- Definition

Weighted average prepayment speed percentage used to find the present value of an amount to be received in the future as an input to measure fair value.

+ References

No definition available.

+ Details

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- Definition

Amount of contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer, net of valuation allowance for impairment of recognized servicing assets.

+ References

No definition available.

+ Details

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- Definition

Percentage of loan servicing rights that are mortgage loans.

+ References

No definition available.

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- Definition

The principal balance of the loans serviced for others related to the Company's loan servicing rights.

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No definition available.

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- Definition

The designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=68078379&loc=d3e122625-111746

+ Details

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- References

No definition available.

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