Information Pertaining to Held to Maturity Securities With Gross Unrealized Losses (Detail) (Corporate Bond, USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2014	Dec. 31, 2013
Corporate Bond
Schedule of Held-to-maturity Securities [Line Items]
Less than 12 months Fair Value	$ 9,763	$ 28,839
Less than 12 months Gross Unrealized Losses	(14)	(40)
12 months or longer Fair Value	5,163	2,614
12 months or longer Gross Unrealized Losses	(11)	(3)
Total Fair Value	14,926	31,453
Total Gross Unrealized Losses	$ (25)	$ (43)

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

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

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

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

-Publisher FASB

-Name Accounting Standards Codification

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Amount of unrealized loss before deducting unrealized gain on investments in held-to-maturity securities that have been in a 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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