SHARE-BASED COMPENSATION: (Tables)

6 Months Ended

Sep. 30, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of option activity

Stock option activity for the six months endedSeptember 30, 2017 was: 

					Weighted-average
			Weighted-average		remaining	Aggregate
	Number of		exercise price		contractual term	Intrinsic value
	shares		per share		(in years)	(in thousands)
Outstanding at March 31, 2017	3,033,071		$	13.14
Performance units converted to options	299,641		$	21.32
Exercised	(396,912	)	$	16.31		$	4,039
Forfeited or canceled	(63,540	)	$	20.20
Outstanding at September 30, 2017	2,872,260		$	13.40	6.1	$	32,439
Exercisable at September 30, 2017	2,174,071		$	13.65	5.4	$	24,016

Summary of stock options outstanding and exercisable

A summary of stock options outstanding and exercisable as of September 30, 2017 was:

					Options outstanding				Options exercisable
Range of						Weighted-average	Weighted-average			Weighted-average
exercise price					Options	remaining	exercise price		Options	exercise price
per share					outstanding	contractual life	per share		exercisable	per share
$	0.61	—	$	9.99	746,976	6.8 years	$	1.68	473,841	$	1.74
$	10.00	—	$	19.99	1,305,746	5.1 years	$	14.99	1,109,428	$	14.50
$	20.00	—	$	24.99	799,986	7.0 years	$	21.29	576,139	$	21.31
$	25.00	—	$	32.85	19,552	6.1 years	$	32.85	14,663	$	32.85
					2,872,260	6.1 years	$	13.40	2,174,071	$	13.65

Schedule of stock appreciation right (SAR) activity

SAR activity for the six months endedSeptember 30, 2017 was:

					Weighted-average
			Weighted-average		remaining	Aggregate
	Number		exercise price		contractual term	intrinsic value
	of shares		per share		(in years)	(in thousands)
Outstanding at March 31, 2017	245,404		$	40.00
Forfeited or canceled	(245,404	)	$	40.00
Outstanding at September 30, 2017	—		$	—	—	$	—

Performance stock option unit activity for the six months endedSeptember 30, 2017 was:

					Weighted-average
			Weighted-average		remaining	Aggregate
	Number		exercise price		contractual term	intrinsic value
	of shares		per share		(in years)	(in thousands)
Outstanding at March 31, 2017	555,123		$	21.41
Performance units converted to options	(183,322	)	$	21.41
Forfeited or canceled	(11,291	)	$	21.32
Outstanding at September 30, 2017	360,510		$	21.41	2.1	$	1,168
Exercisable at September 30, 2017	—		$	—	—	$	—

Schedule of non-vested time-vesting restricted stock unit activity

Non-vested time-vesting restricted stock unit activity for the six months endedSeptember 30, 2017 was:

			Weighted-average
			fair value per		Weighted-average
	Number		share at grant		remaining contractual
	of shares		date		term (in years)
Outstanding at March 31, 2017	3,307,577		$	22.57	2.45
Granted	1,424,678		$	26.09
Vested	(691,507	)	$	20.44
Forfeited or canceled	(196,056	)	$	22.51
Outstanding at September 30, 2017	3,844,692		$	24.26	2.59

Schedule of non-vested performance-based restricted stock units activity

Non-vested performance-based restricted stock unit activity for the six months endedSeptember 30, 2017 was:

			Weighted-average
			fair value per		Weighted-average
	Number		share at grant		remaining contractual
	of shares		date		term (in years)
Outstanding at March 31, 2017	732,711		$	20.89	1.13
Granted	421,918		$	26.70
Additional performance shares	94,775		$	19.46
Vested	(252,760	)	$	19.46
Forfeited or canceled	(13,498	)	$	18.91
Outstanding at September 30, 2017	983,146		$	23.64	1.62

Schedule of other performance unit activity

Other performance-based stock unit activity for the six months endedSeptember 30, 2017 was: 

			Weighted-average
			fair value per		Weighted-average
	Number		share at grant		remaining contractual
	of shares		date		term (in years)
Outstanding at March 31, 2017	597,193		$	4.14	0.30
Vested	(24,573	)	$	2.94
Forfeited or canceled	(461,509	)	$	3.92
Outstanding at September 30, 2017	111,111		$	5.33	0.50