Comprehensive Income - Schedule of Comprehensive Income (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Comprehensive Income Net Of Tax [Abstract]
Net unrealized holding loss on securities available for sale		$ (2,644)	$ (2,011)	$ (3,671)	$ (78)
Amortization of net unrealized holding loss on securities available for sale transferred to held to maturity	[1]	40	74	167	103
Fair value adjustments on derivatives		(11,615)	7,489	(9,772)	9,134
Amortization of actuarial loss		11	11	22	22
Net actuarial loss	[2]			(59)	(83)
Net change in benefit plan accrued expense		11	11	(37)	(61)
Other comprehensive (loss) income before taxes		(14,208)	5,563	(13,313)	9,098
Stranded tax effects	[3]		(1,381)		(1,381)
Tax effect	[4]	4,192	(910)	3,580	(2,349)
Total Other Comprehensive (Loss) Income		$ (10,016)	$ 3,272	$ (9,733)	$ 5,368

[1] Represents amounts reclassified out of accumulated other comprehensive income and included in interest income on taxable securities.

[2] Represents amounts reclassified out of accumulated other comprehensive income and included in the computation of net periodic pension expense. See Note 15 – Benefit Plans for additional information.

[3] Represents amounts reclassified from accumulated other comprehensive income that did not reflect the appropriate tax rate.

[4] The amounts included in income taxes for items reclassified out of accumulated other comprehensive income totaled $3 and $23 for the three and six months ended December 31, 2018, respectively, and $148 and $119 for the three and six months ended December 31, 2017.