Gross Realized Gains and Losses on Sales and Calls of Available for Sale Securities (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Schedule of Available-for-sale Securities [Line Items]
Gross realized gains	$ 10,227	$ 10,532	$ 11,219	$ 22,762
Gross realized losses	(2,713)	(214)	(2,713)	(214)
Total Realized Gains on Sales and Calls of AFS Securities, Net	7,976	10,318	9,955	22,881
Call Option
Schedule of Available-for-sale Securities [Line Items]
Gross realized gains	462		1,449	333
Gross realized losses

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

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This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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