Equity - Summary of Dividends Paid Per Share (Detail) - $ / shares	9 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Class A Common Stock [Member]
Class of Stock [Line Items]
Cash dividend paid per share	$ 0.10	$ 0.10
Class B Common Stock [Member]
Class of Stock [Line Items]
Cash dividend paid per share	$ 0.10	$ 0.10