Equity - Additional Information (Detail) - USD ($)	1 Months Ended				3 Months Ended		9 Months Ended		24 Months Ended
	Feb. 28, 2017	Aug. 31, 2016	Feb. 28, 2016	Aug. 31, 2015	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	May 05, 2017	May 31, 2013
Class of Stock [Line Items]
Aggregate cost of shares repurchased							$ 0	$ 39,000,000
Cash dividend declared					$ 0.10	$ 0.10	$ 0.20	$ 0.20
Dividend declaration date	2017-02	2016-08	2016-02	2015-08
Dividend payable date	Apr. 19, 2017	Oct. 19, 2016	Apr. 13, 2016	Oct. 21, 2015
Dividend record date	Mar. 15, 2017	Sep. 14, 2016	Mar. 09, 2016	Sep. 16, 2015
Subsequent Event [Member]
Class of Stock [Line Items]
Remaining authorized amount under stock repurchase program									$ 429,000,000
Class A Common Stock [Member]
Class of Stock [Line Items]
Aggregate amount of shares authorized to be repurchased										$ 500,000,000
Number of shares repurchased							0
Cash dividend declared	$ 0.10	$ 0.10
Class A Common Stock [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Number of shares repurchased									5,200,000
Aggregate cost of shares repurchased									$ 71,000,000
Class B Common Stock [Member]
Class of Stock [Line Items]
Cash dividend declared	$ 0.10	$ 0.10