Preferred and Common Stockholder's Equity - Additional Information (Detail) - USD ($)	Dec. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2016
Class of Stock [Line Items]
Preferred stock, shares authorized	5,000,000.0
Preferred stock, par value	$ 0.01
Preferred stock, shares outstanding	0
Common stock, shares authorized	150,000,000.0
Common stock, par value	$ 0.01
Common stock, shares issued	74,500,000	73,500,000	70,600,000
Common stock, shares outstanding	74,500,000	73,500,000	70,600,000
Share repurchase program, remaining authorized repurchase amount	$ 110,700,000
Eighth Share Repurchase Program [Member]
Class of Stock [Line Items]
Share repurchase program, authorized amount				$ 200,000,000.0