Comprehensive Income - Schedule of Comprehensive Income (Parenthetical) (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Tax effect	[1]	$ (4,192)	$ 910	$ (3,580)	$ 2,349
Reclassification Out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Tax effect		$ 3	$ 148	$ 23	$ 119

[1] 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.