Summary of Significant Accounting Policies -Basic and Diluted Weighted Average Shares Outstanding (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Basic weighted-average shares outstanding (in shares)	46,752	39,151	46,701	39,004
Effect of dilutive equity instruments (in shares)	695	834	837	916
Diluted weighted-average shares outstanding (in shares)	47,447	39,985	47,538	39,920
Antidilutive securities excluded from computation of earnings per share (in shares)	23	9	162	6