STOCKHOLDERS' EQUITY: (Details 3) (USD $)	12 Months Ended
	Mar. 31, 2013
Stock options outstanding and exercisable by exercise price range
Options outstanding (in shares)	8,193,248
Options outstanding - Weighted-average remaining contractual life	3 years 7 months 20 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 20.85
Options exercisable (in shares)	7,045,869
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 22.05
Range of exercise price per share from $6.32 to $9.62
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	$ 6.32
Exercise price per share, high end of range (in dollars per share)	$ 9.62
Options outstanding (in shares)	98,798
Options outstanding - Weighted-average remaining contractual life	5 years 3 months 7 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 8.69
Options exercisable (in shares)	71,798
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 8.61
Range of exercise price per share from $10.22 to $15.00
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	$ 10.22
Exercise price per share, high end of range (in dollars per share)	$ 15.00
Options outstanding (in shares)	2,308,398
Options outstanding - Weighted-average remaining contractual life	6 years 5 months 12 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 13.04
Options exercisable (in shares)	1,211,163
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 12.62
Range of exercise price per share from $15.10 to $19.82
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)	$ 19.82
Options outstanding (in shares)	1,700,968
Options outstanding - Weighted-average remaining contractual life	3 years 18 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 16.71
Options exercisable (in shares)	1,677,824
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 16.70
Range of exercise price per share from $20.12 to $25.00
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	$ 20.12
Exercise price per share, high end of range (in dollars per share)	$ 25.00
Options outstanding (in shares)	2,081,052
Options outstanding - Weighted-average remaining contractual life	3 years 1 month 6 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 22.92
Options exercisable (in shares)	2,081,052
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 22.92
Range of exercise price per share from $25.98 to $29.30
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	$ 25.98
Exercise price per share, high end of range (in dollars per share)	$ 29.30
Options outstanding (in shares)	1,095,987
Options outstanding - Weighted-average remaining contractual life	1 year 5 months 12 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 26.69
Options exercisable (in shares)	1,095,987
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 26.69
Range of exercise price per share from $30.93 to $39.12
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	$ 30.93
Exercise price per share, high end of range (in dollars per share)	$ 39.12
Options outstanding (in shares)	668,512
Options outstanding - Weighted-average remaining contractual life	1 year 2 months 19 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 35.81
Options exercisable (in shares)	668,512
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 35.81
Range of exercise price per share from $40.88 to $62.06
Stock options outstanding and exercisable by exercise price range
Exercise price per share, low end of range (in dollars per share)	$ 40.88
Exercise price per share, high end of range (in dollars per share)	$ 62.06
Options outstanding (in shares)	239,533
Options outstanding - Weighted-average remaining contractual life	1 year 6 months 25 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 44.07
Options exercisable (in shares)	239,533
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 44.07