Share Repurchase (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended		21 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Jan. 29, 2020	Nov. 07, 2018
Equity, Class of Treasury Stock [Line Items]
Total number of share repurchases	1,164,308	1,266,160	3,838,275	3,631,611	6,383,431
Total cost of share repurchases	$ 36,870	$ 60,970	$ 136,889	$ 176,903	$ 254,769
Average price paid per share	$ 31.67	$ 48.15	$ 35.66	$ 48.71	$ 39.91
Authorized On January Thirty-One Two-Thousand Twenty [Member]
Equity, Class of Treasury Stock [Line Items]
Authorized amount for repurchase						$ 300,000
Maximum | Authorized on November 7, 2018
Equity, Class of Treasury Stock [Line Items]
Authorized amount for repurchase							$ 300,000
Remaining authorized amount for repurchase	$ 45,200		$ 45,200		$ 45,200