Fair Value of Financial Instruments - Schedule of Assets Measured At Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Jun. 30, 2018
Assets:
Securities available for sale, Fair value	$ 543,832	$ 590,562
Mortgage-backed securities available for sale	122,770	134,523
Securities available for sale	666,602	725,085
Interest rate swaps	22,109	31,881
Total assets	688,711	756,966
Interest Rate Swaps [Member]
Assets:
Interest rate swaps	22,109	31,881
Debt Securities [Member]
Assets:
Securities available for sale, Fair value	543,832	590,562
Debt Securities [Member] \| U.S. Agency Securities [Member]
Assets:
Securities available for sale, Fair value	3,942	4,411
Debt Securities [Member] \| Obligations of State and Political Subdivisions [Member]
Assets:
Securities available for sale, Fair value	26,205	26,088
Debt Securities [Member] \| Asset-backed Securities [Member]
Assets:
Securities available for sale, Fair value	180,828	182,620
Debt Securities [Member] \| Collateralized Loan Obligations [Member]
Assets:
Securities available for sale, Fair value	184,439	226,066
Debt Securities [Member] \| Corporate Bonds [Member]
Assets:
Securities available for sale, Fair value	144,692	147,594
Debt Securities [Member] \| Trust Preferred Securities [Member]
Assets:
Securities available for sale, Fair value	3,726	3,783
Collateralized Mortgage Obligations Excluding Pass Through Securities [Member]
Assets:
Mortgage-backed securities available for sale	23,019	24,292
Residential Pass-Through Securities [Member]
Assets:
Mortgage-backed securities available for sale	91,918	102,359
Commercial Pass-Through Securities [Member]
Assets:
Mortgage-backed securities available for sale	7,833	7,872
Interest Rate Swaps and Caps [Member]
Assets:
Interest rate swaps		31,881
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Securities available for sale, Fair value	542,832	589,562
Mortgage-backed securities available for sale	122,770	134,523
Securities available for sale	665,602	724,085
Total assets	687,711	755,966
Significant Other Observable Inputs (Level 2) [Member] \| Interest Rate Swaps [Member]
Assets:
Interest rate swaps	22,109
Significant Other Observable Inputs (Level 2) [Member] \| Debt Securities [Member] \| U.S. Agency Securities [Member]
Assets:
Securities available for sale, Fair value	3,942	4,411
Significant Other Observable Inputs (Level 2) [Member] \| Debt Securities [Member] \| Obligations of State and Political Subdivisions [Member]
Assets:
Securities available for sale, Fair value	26,205	26,088
Significant Other Observable Inputs (Level 2) [Member] \| Debt Securities [Member] \| Asset-backed Securities [Member]
Assets:
Securities available for sale, Fair value	180,828	182,620
Significant Other Observable Inputs (Level 2) [Member] \| Debt Securities [Member] \| Collateralized Loan Obligations [Member]
Assets:
Securities available for sale, Fair value	184,439	226,066
Significant Other Observable Inputs (Level 2) [Member] \| Debt Securities [Member] \| Corporate Bonds [Member]
Assets:
Securities available for sale, Fair value	144,692	147,594
Significant Other Observable Inputs (Level 2) [Member] \| Debt Securities [Member] \| Trust Preferred Securities [Member]
Assets:
Securities available for sale, Fair value	2,726	2,783
Significant Other Observable Inputs (Level 2) [Member] \| Collateralized Mortgage Obligations Excluding Pass Through Securities [Member]
Assets:
Mortgage-backed securities available for sale	23,019	24,292
Significant Other Observable Inputs (Level 2) [Member] \| Residential Pass-Through Securities [Member]
Assets:
Mortgage-backed securities available for sale	91,918	102,359
Significant Other Observable Inputs (Level 2) [Member] \| Commercial Pass-Through Securities [Member]
Assets:
Mortgage-backed securities available for sale	7,833	7,872
Significant Other Observable Inputs (Level 2) [Member] \| Interest Rate Swaps and Caps [Member]
Assets:
Interest rate swaps		31,881
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Securities available for sale, Fair value	1,000	1,000
Securities available for sale	1,000	1,000
Total assets	1,000	1,000
Significant Unobservable Inputs (Level 3) [Member] \| Debt Securities [Member] \| Trust Preferred Securities [Member]
Assets:
Securities available for sale, Fair value	$ 1,000	$ 1,000

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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