SHARE-BASED COMPENSATION: (Tables)

3 Months Ended

Jun. 30, 2017

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

Schedule of option activity

Stock option activity for the three months endedJune 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	(130,157	)	$	14.66		$	1,532
Forfeited or canceled	(2,052	)	$	14.80
Outstanding at June 30, 2017	3,200,503		$	13.85	5.9	$	38,971
Exercisable at June 30, 2017	2,412,279		$	14.49	5.1	$	27,826

Summary of stock options outstanding and exercisable

A summary of stock options outstanding and exercisable as of June 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	801,586	7.1 years	$	1.67	460,516	$	1.71
$	10.00	—	$	19.99	1,396,449	5.2 years	$	15.10	1,184,653	$	14.62
$	20.00	—	$	24.99	982,916	6.0 years	$	21.62	752,447	$	21.74
$	25.00	—	$	32.85	19,552	6.4 years	$	32.85	14,663	$	32.85
					3,200,503	5.9 years	$	13.85	2,412,279	$	14.49

Schedule of stock appreciation right (SAR) activity

SAR activity for the three months endedJune 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 June 30, 2017	—		$	—	—	$	—

Performance stock option unit activity for the three months endedJune 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	(6,954	)	$	21.32
Outstanding at June 30, 2017	364,847		$	21.41	2.4	$	1,668
Exercisable at June 30, 2017	—		$	—	—	$	—

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

Non-vested time-vesting restricted stock unit activity for the three months endedJune 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	1,156,431		$	26.55
Vested	(542,617	)	$	20.25
Forfeited or canceled	(74,744	)	$	21.87
Outstanding at June 30, 2017	3,846,647		$	24.11	2.78

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

Non-vested performance-based restricted stock unit activity for the three months endedJune 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	334,734		$	27.43
Additional performance shares	94,775		$	19.46
Vested	(252,760	)	$	19.46
Forfeited or canceled	(586	)	$	17.98
Outstanding at June 30, 2017	908,874		$	23.55	1.68

Schedule of other performance unit activity

Other performance-based stock unit activity for the three months endedJune 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
Forfeited or canceled	(201,464	)	$	5.18
Outstanding at June 30, 2017	395,729		$	3.61	0.21