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Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Available for Sale (Detail) (USD $) In Thousands, unless otherwise specified | Jun. 30, 2014 | Jun. 30, 2013
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Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | $ 553,144 |
Gross Unrealized Gains | 8,933 |
Gross Unrealized Losses | (945) |
Estimated Fair Value, Total | 561,132 |
U.S. treasury and other federal agencies [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 458,976 |
Gross Unrealized Gains | 2,061 |
Gross Unrealized Losses | (212) |
Estimated Fair Value, Total | 460,825 |
Mortgage-backed securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 28,390 |
Gross Unrealized Gains | 678 |
Gross Unrealized Losses | (508) |
Estimated Fair Value, Total | 28,560 | 16,031
States and political subdivisions [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 53,652 |
Gross Unrealized Gains | 1,918 |
Gross Unrealized Losses | (48) |
Estimated Fair Value, Total | 55,522 |
Other securities [Member] |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 12,126 |
Gross Unrealized Gains | 4,276 |
Gross Unrealized Losses | (177) |
Estimated Fair Value, Total | $ 16,225 |

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- Definition Amount of accumulated pre-tax unrealized gain before deducting pre-tax unrealized losses on investments in available-for-sale securities impacting investments. + References No definition available. + Details
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- Definition Amount of accumulated pre-tax unrealized loss before deducting pre-tax unrealized gain on investments in available-for-sale securities impacting investments. + References No definition available. + Details
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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 + Details
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- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.2) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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