SHARE-BASED COMPENSATION: (Details 2) (USD $)	3 Months Ended
	Jun. 30, 2013
Stock options outstanding and exercisable by exercise price range
Options outstanding (in shares)	8,053,253
Options outstanding - Weighted-average remaining contractual life	3 years 7 months 17 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 20.92
Options exercisable (in shares)	6,813,217
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 21.92
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)	68,298
Options outstanding - Weighted-average remaining contractual life	4 years 7 months 2 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 8.60
Options exercisable (in shares)	68,298
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 8.60
Range of exercise price per share from $11.08 to $15.00
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)	$ 15.00
Options outstanding (in shares)	2,195,410
Options outstanding - Weighted-average remaining contractual life	6 years 2 months 23 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 13.02
Options exercisable (in shares)	1,255,989
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 12.65
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)	1,533,823
Options outstanding - Weighted-average remaining contractual life	2 years 9 months 11 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 16.68
Options exercisable (in shares)	1,524,041
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 16.67
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)	2,312,306
Options outstanding - Weighted-average remaining contractual life	3 years 9 months 4 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 22.74
Options exercisable (in shares)	2,021,473
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)	1,095,763
Options outstanding - Weighted-average remaining contractual life	1 year 2 months 12 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 26.69
Options exercisable (in shares)	1,095,763
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)	640,123
Options outstanding - Weighted-average remaining contractual life	1 year 4 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 35.79
Options exercisable (in shares)	640,123
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 35.79
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)	207,530
Options outstanding - Weighted-average remaining contractual life	1 year 6 months 11 days
Options outstanding - Weighted-average exercise price per share (in dollars per share)	$ 43.40
Options exercisable (in shares)	207,530
Options exercisable - Weighted-average exercise price per share (in dollars per share)	$ 43.40