Stock-Based Employee Compensation (Restricted and Performance-Based Stock Unit Activity) (Details) - Restricted Stock Units (RSUs) shares in Thousands	9 Months Ended
	Dec. 31, 2017 $ / shares shares
Shares
Beginning Balance outstanding (in shares) | shares	3,840
Granted (in shares) | shares	2,349
Released (in shares) | shares	(1,409)
Forfeited (in shares) | shares	(356)
Ending Balance outstanding (in shares) | shares	4,752
Weighted-average grant date fair value per share
Beginning Balance outstanding (in dollars per share) | $ / shares	$ 18.88
Granted (in dollars per share) | $ / shares	24.34
Released (in dollars per share) | $ / shares	17.34
Forfeited (in dollars per share) | $ / shares	21.63
Ending Balance outstanding (in dollars per share) | $ / shares	$ 22.16
GigPeak, Inc.
Shares
Assumed from GigPeak acquisition (in shares) | shares	328
Weighted-average grant date fair value per share
Assumed from GigPeak acquisition (in dollars per share) | $ / shares	$ 23.62