Held to Maturity Securities in Continuous Unrealized Loss Position (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Fair Value	$ 27,397
Less than 12 Months, Unrealized Losses	(130)
12 Months or Longer, Fair Value
12 Months or Longer, Unrealized Losses
Fair Value	27,397
Unrealized Losses	(130)
U.S. Agency securities
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Fair Value	19,958
Less than 12 Months, Unrealized Losses	(87)
12 Months or Longer, Fair Value
12 Months or Longer, Unrealized Losses
Fair Value	19,958
Unrealized Losses	(87)
Corporate securities
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 Months, Fair Value	7,439
Less than 12 Months, Unrealized Losses	(43)
12 Months or Longer, Fair Value
12 Months or Longer, Unrealized Losses
Fair Value	7,439
Unrealized Losses	$ (43)

Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (c)

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Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity that have been in a continuous loss position for twelve months or longer.

+ References

Reference 1: 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=27724398&loc=d3e27337-111563

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This item represents the fair value of securities categorized as held-to-maturity which are in an unrealized loss position.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

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-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

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Amount of accumulated unrealized loss on investments in debt securities classified as held-to-maturity that have been in a continuous loss position for less than twelve months.

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This item represents the fair value of securities categorized as held-to-maturity that have been in a continuous unrealized loss position for less than twelve months.

+ References

Reference 1: 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=27724398&loc=d3e27337-111563

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This item represents the fair value of securities categorized as held-to-maturity securities that have been in a continuous unrealized loss position for twelve months or longer.

+ References

Reference 1: 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=27724398&loc=d3e27337-111563

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