SHARE-BASED COMPENSATION: (Details 2)	9 Months Ended
	Dec. 31, 2015 $ / shares shares
Stock options outstanding and exercisable by exercise price range
Options outstanding (in shares) | shares	3,908,957
Options outstanding - Weighted-average remaining contractual life	5 years 1 month 10 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 14.04
Options exercisable (in shares) | shares	2,678,043
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 14.27
Range of exercise price per share from $0.63 to $8.90
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	0.63
Exercise price per share, high end of range (in dollars per share)	$ 8.90
Options outstanding (in shares) | shares	809,387
Options outstanding - Weighted-average remaining contractual life	6 years 3 months 22 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 1.70
Options exercisable (in shares) | shares	439,366
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 1.69
Range of exercise price per share from $11.08 to $14.42
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	11.08
Exercise price per share, high end of range (in dollars per share)	$ 14.42
Options outstanding (in shares) | shares	1,204,258
Options outstanding - Weighted-average remaining contractual life	4 years 4 months 13 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 13.18
Options exercisable (in shares) | shares	1,090,931
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 13.16
Range of exercise price per share from $15.10 to $19.76
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	15.10
Exercise price per share, high end of range (in dollars per share)	$ 19.76
Options outstanding (in shares) | shares	851,168
Options outstanding - Weighted-average remaining contractual life	5 years 7 months 6 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 17.15
Options exercisable (in shares) | shares	436,121
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 16.57
Range of exercise price per share from $20.44 to $25.00
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	20.44
Exercise price per share, high end of range (in dollars per share)	$ 25.00
Options outstanding (in shares) | shares	1,024,502
Options outstanding - Weighted-average remaining contractual life	4 years 6 months 29 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 21.87
Options exercisable (in shares) | shares	701,761
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 22.18
Range of exercise price per share from $26.33 to $62.06
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	26.33
Exercise price per share, high end of range (in dollars per share)	$ 62.06
Options outstanding (in shares) | shares	19,642
Options outstanding - Weighted-average remaining contractual life	7 years 9 months 29 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 32.83
Options exercisable (in shares) | shares	9,864
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 32.80