Acquisitions 2 (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Dec. 31, 2016	Dec. 31, 2016
Unaudited pro forma combined financial information for the Company, Automic and Veracode as though combined as of beginning of fiscal year 2017
Total revenue	$ 1,061	$ 3,178
Net income	$ 181	$ 527
Basic income per common share (in dollars per share)	$ 0.43	$ 1.26
Diluted income per common share (in dollars per share)	$ 0.43	$ 1.25